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000
FXUS63 KAPX 210452
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1252 AM EDT TUE APR 21 2015

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 1242 AM EDT TUE APR 21 2015

...COLD/DREARY AND SHOWERY...

SYNOPTIC PATTERN AND OBSERVATIONS:

EARLY THIS MORNING...LARGE SPIRALING SFC AND UPPER LEVEL LOW
PRESSURE DRIFTING NORTH WITH TIGHT PRESSURE GRADIENT AND DEEP
MOISTURE BLOWING COLD AIR THROUGH THE GREAT LAKES. FREEZING LEVEL
HAVE STEADILY BEEN LOWERING THROUGH THE NIGHT. PREVIOUS BAND OF
LIGHT RAIN MIXED WITH LIGHT SNOW...BUT PRECIPITATION HAS TAPERED OFF
TO OCCASIONAL SPITS INTO MAINLY THE HIGHER TERRAIN...AS DEEPER
MOISTURE ALOFT HAS EXITED...PER WATER VAPOR IMAGERY. TEMPERATURES
WERE IN THE VERY CHILLY MIDDLE TO UPPER 30S.

FURTHER UPSTREAM ACROSS MN/WI...NEXT BATCH OF DEEPER MOISTURE AND
DEFINED SFC TROUGH ARE SEEN ROTATING TOWARD THE WESTERN GREAT LAKES.
THIS IS THE NEXT AREA OF MORE WIDESPREAD LIGHT RAIN/SNOW.

SYNOPTIC PATTERN EVOLUTION AND ASSOCIATED WEATHER:

SPITS OF LIGHT RAIN AND SNOW TO CONTINUE INTO THE DAYBREAK
HOURS...WHILE THE UPPER/SFC LOWS DRAG THE AFOREMENTIONED SFC TROUGH
AND DEEPER MOISTURE INTO NRN MICHIGAN. STEEP LAPSE RATES AIDED BY
APRIL SUN ANGLE WILL WORK IN TANDEM WITH THE FRONTAL CONVERGENCE TO
FIRE OFF NUMEROUS LIGHT RAIN SHOWERS. MAYBE SOME HIGHER TERRAIN
AREAS SEEING BRIEF SNOW MIXING IN...AS WET BULBS CLIMB TO 1600 FEET
AT THE PEAK OF THE SHOWER COVERAGE. BETTER COVERAGE LIKELY TIED TO
THE FRONT WHICH WILL PRIMARILY BE IN WESTERN AREAS OF THE CWA.
THINGS WILL NOT GET MUCH BETTER HEADING INTO TONIGHT...DESPITE
SHOWERS TAPERING OFF INTO THE EARLY EVENING FROM DEPARTING "SUN".
MORE DEEP MOISTURE AND WEAK EMBEDDED VORTICITY MAXIMA WRAP INTO THE
REGION...WHILE THE SFC TROUGH WALKS ACROSS NRN MICHIGAN. THE ENTIRE
ATMOSPHERE WILL CONTINUALLY COOL...TO WHERE SNOW WILL BE THE PRIMARY
PRECIP TYPE. WONDERFUL. ONGOING FORECAST OVER SEVERAL TENTHS OF AN
INCH OF SNOW SEEM OK....ESPECIALLY IN HIGHER TERRAIN AREAS OF NRN
LOWER. THERE JUST WONT BE STRONG FORCING...SO DON`T FORESEE ANYTHING
CRAZY...LIKE WAKING UP TO MORE THAN AN INCH OF SNOW.

HIGH TEMPS TODAY IN THE LOW TO MID 40S...MILDEST IN DOWNSLOPING
REGIMES OF NE LOWER. LOWS TONIGHT WILL BE IN THE UPPER 20S TO LOWER
30S MOST AREAS.

&&

.SHORT TERM...(WEDNESDAY THROUGH THURSDAY NIGHT)
ISSUED AT 1242 AM EDT TUE APR 21 2015

THE PATTERN THROUGH THE REST OF THE WEEK WILL BE DOMINATED BY A
MID/UPPER LEVEL LOW MOVING SLOWLY THROUGH THE NORTHERN GREAT LAKES
TOWARD SRN QUEBEC. THIS WILL BRING UNSETTLED WEATHER ALONG WITH
BELOW NORMAL TEMPERATURES.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO
THE ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING
DAYTIME HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE
AREA WITHIN THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST
SCT SHOWERY PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN
OVER OVER THE SE CWA DURING PEAK HEATING. ALTHOUGH THERE WILL BE
SOME LAKE CONTRIBUTION AS 850 MB TEMPS RANGE FROM -9C TO
-12C...THE BEST COVERAGE DURING THE DAYTIME SHOULD BE IN THE
AFTERNOON INLAND FROM LAKE SUPERIOR WHERE HEATING WILL BE
STRONGEST WITH STEEP SFC-700 MB LAPSE RATES 700 MB TEMPS TO AROUND
-18C WED WILL ONLY MODERATE TO NEAR -14C THU. HIGH TEMPS BOTH DAYS
SHOULD BE WELL BELOW NORMAL...IN THE MID 30S TO AROUND 40.

&&

.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 1242 AM EDT TUE APR 21 2015

FRI-MON...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM
MAINTAIN TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE
WEEKEND WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH
DRIER AND WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE
EXPECTED TO REMAIN BELOW NORMAL WITH LOW(GFS/GEFS)OR NO(ECMWF)
PCPN CHANCES.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1242 AM EDT TUE APR 21 2015

...AFTERNOON SHOWERS...

CIGS HAVE CLIMBED TO VFR AS DEEP MOISTURE HAS CROSSED NRN MICHIGAN.
STRONG LOW PRESSURE HOWEVER WILL DRAG A SFC TROUGH AND DEEPER
MOISTURE BACK INTO THE REGION TUESDAY. NUMEROUS RAIN SHOWERS WILL
FIRE OFF WITH PERIODIC PRIMARILY MVFR CIGS ANTICIPATED. BETTER
COVERAGE OF SHOWERS EXPECTED ACROSS THE NW LOWER AIRPORTS. AS THIS
TROUGH DRIFTS BY INTO THE OVERNIGHT HOURS TUESDAY NIGHT...THE AIR
MASS BECOMES COLDER AND COLDER. EVENTUALLY ALL AREAS WILL BE COLD
ENOUGH FOR SNOW. LOW SNOWFALL RATES OF COURSE...LESS THAN AN INCH
EXPECTED...LIKELY ONLY A FEW TENTHS.

SW/WSW WINDS REMAINING RATHER BLUSTERY...ESPECIALLY TUESDAY
AFTERNOON.

&&

.MARINE...
ISSUED AT 1242 AM EDT TUE APR 21 2015

SW WINDS WILL GRADUALLY TURN OUT OF THE WEST THEN NW TONIGHT...AS
SFC LOW PRESSURE PULLS NORTH OF MICHIGAN...SHIFTING THE FOCUS OF
THE STRONGEST WINDS AND BIGGEST WAVES FROM THE LAKE HURON
SHORELINE TO THE LAKE MICHIGAN SHORELINE. DID EXTEND THE ADVISORY
FOR THE NEARSHORE WATERS SOUTH OF STURGEON POINT THROUGH
TODAY...AND MAY NEED TO EXTEND FURTHER INTO TUESDAY EVENING.
CHILLY AND OCCASIONALLY GUSTY WILL BE THE THEME THROUGH THE WEEK.
WAVES MAY STAY CHOPPY ENOUGH ON LAKE MICHIGAN FOR
ADDITIONAL/EXTENDED ADVISORIES.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LHZ349.

LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LMZ323-342-
     344>346.

LS...NONE.
&&

$$

NEAR TERM...SMD
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...SMD
MARINE...SMD



000
FXUS63 KAPX 210452
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1252 AM EDT TUE APR 21 2015

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 1242 AM EDT TUE APR 21 2015

...COLD/DREARY AND SHOWERY...

SYNOPTIC PATTERN AND OBSERVATIONS:

EARLY THIS MORNING...LARGE SPIRALING SFC AND UPPER LEVEL LOW
PRESSURE DRIFTING NORTH WITH TIGHT PRESSURE GRADIENT AND DEEP
MOISTURE BLOWING COLD AIR THROUGH THE GREAT LAKES. FREEZING LEVEL
HAVE STEADILY BEEN LOWERING THROUGH THE NIGHT. PREVIOUS BAND OF
LIGHT RAIN MIXED WITH LIGHT SNOW...BUT PRECIPITATION HAS TAPERED OFF
TO OCCASIONAL SPITS INTO MAINLY THE HIGHER TERRAIN...AS DEEPER
MOISTURE ALOFT HAS EXITED...PER WATER VAPOR IMAGERY. TEMPERATURES
WERE IN THE VERY CHILLY MIDDLE TO UPPER 30S.

FURTHER UPSTREAM ACROSS MN/WI...NEXT BATCH OF DEEPER MOISTURE AND
DEFINED SFC TROUGH ARE SEEN ROTATING TOWARD THE WESTERN GREAT LAKES.
THIS IS THE NEXT AREA OF MORE WIDESPREAD LIGHT RAIN/SNOW.

SYNOPTIC PATTERN EVOLUTION AND ASSOCIATED WEATHER:

SPITS OF LIGHT RAIN AND SNOW TO CONTINUE INTO THE DAYBREAK
HOURS...WHILE THE UPPER/SFC LOWS DRAG THE AFOREMENTIONED SFC TROUGH
AND DEEPER MOISTURE INTO NRN MICHIGAN. STEEP LAPSE RATES AIDED BY
APRIL SUN ANGLE WILL WORK IN TANDEM WITH THE FRONTAL CONVERGENCE TO
FIRE OFF NUMEROUS LIGHT RAIN SHOWERS. MAYBE SOME HIGHER TERRAIN
AREAS SEEING BRIEF SNOW MIXING IN...AS WET BULBS CLIMB TO 1600 FEET
AT THE PEAK OF THE SHOWER COVERAGE. BETTER COVERAGE LIKELY TIED TO
THE FRONT WHICH WILL PRIMARILY BE IN WESTERN AREAS OF THE CWA.
THINGS WILL NOT GET MUCH BETTER HEADING INTO TONIGHT...DESPITE
SHOWERS TAPERING OFF INTO THE EARLY EVENING FROM DEPARTING "SUN".
MORE DEEP MOISTURE AND WEAK EMBEDDED VORTICITY MAXIMA WRAP INTO THE
REGION...WHILE THE SFC TROUGH WALKS ACROSS NRN MICHIGAN. THE ENTIRE
ATMOSPHERE WILL CONTINUALLY COOL...TO WHERE SNOW WILL BE THE PRIMARY
PRECIP TYPE. WONDERFUL. ONGOING FORECAST OVER SEVERAL TENTHS OF AN
INCH OF SNOW SEEM OK....ESPECIALLY IN HIGHER TERRAIN AREAS OF NRN
LOWER. THERE JUST WONT BE STRONG FORCING...SO DON`T FORESEE ANYTHING
CRAZY...LIKE WAKING UP TO MORE THAN AN INCH OF SNOW.

HIGH TEMPS TODAY IN THE LOW TO MID 40S...MILDEST IN DOWNSLOPING
REGIMES OF NE LOWER. LOWS TONIGHT WILL BE IN THE UPPER 20S TO LOWER
30S MOST AREAS.

&&

.SHORT TERM...(WEDNESDAY THROUGH THURSDAY NIGHT)
ISSUED AT 1242 AM EDT TUE APR 21 2015

THE PATTERN THROUGH THE REST OF THE WEEK WILL BE DOMINATED BY A
MID/UPPER LEVEL LOW MOVING SLOWLY THROUGH THE NORTHERN GREAT LAKES
TOWARD SRN QUEBEC. THIS WILL BRING UNSETTLED WEATHER ALONG WITH
BELOW NORMAL TEMPERATURES.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO
THE ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING
DAYTIME HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE
AREA WITHIN THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST
SCT SHOWERY PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN
OVER OVER THE SE CWA DURING PEAK HEATING. ALTHOUGH THERE WILL BE
SOME LAKE CONTRIBUTION AS 850 MB TEMPS RANGE FROM -9C TO
-12C...THE BEST COVERAGE DURING THE DAYTIME SHOULD BE IN THE
AFTERNOON INLAND FROM LAKE SUPERIOR WHERE HEATING WILL BE
STRONGEST WITH STEEP SFC-700 MB LAPSE RATES 700 MB TEMPS TO AROUND
-18C WED WILL ONLY MODERATE TO NEAR -14C THU. HIGH TEMPS BOTH DAYS
SHOULD BE WELL BELOW NORMAL...IN THE MID 30S TO AROUND 40.

&&

.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 1242 AM EDT TUE APR 21 2015

FRI-MON...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM
MAINTAIN TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE
WEEKEND WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH
DRIER AND WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE
EXPECTED TO REMAIN BELOW NORMAL WITH LOW(GFS/GEFS)OR NO(ECMWF)
PCPN CHANCES.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1242 AM EDT TUE APR 21 2015

...AFTERNOON SHOWERS...

CIGS HAVE CLIMBED TO VFR AS DEEP MOISTURE HAS CROSSED NRN MICHIGAN.
STRONG LOW PRESSURE HOWEVER WILL DRAG A SFC TROUGH AND DEEPER
MOISTURE BACK INTO THE REGION TUESDAY. NUMEROUS RAIN SHOWERS WILL
FIRE OFF WITH PERIODIC PRIMARILY MVFR CIGS ANTICIPATED. BETTER
COVERAGE OF SHOWERS EXPECTED ACROSS THE NW LOWER AIRPORTS. AS THIS
TROUGH DRIFTS BY INTO THE OVERNIGHT HOURS TUESDAY NIGHT...THE AIR
MASS BECOMES COLDER AND COLDER. EVENTUALLY ALL AREAS WILL BE COLD
ENOUGH FOR SNOW. LOW SNOWFALL RATES OF COURSE...LESS THAN AN INCH
EXPECTED...LIKELY ONLY A FEW TENTHS.

SW/WSW WINDS REMAINING RATHER BLUSTERY...ESPECIALLY TUESDAY
AFTERNOON.

&&

.MARINE...
ISSUED AT 1242 AM EDT TUE APR 21 2015

SW WINDS WILL GRADUALLY TURN OUT OF THE WEST THEN NW TONIGHT...AS
SFC LOW PRESSURE PULLS NORTH OF MICHIGAN...SHIFTING THE FOCUS OF
THE STRONGEST WINDS AND BIGGEST WAVES FROM THE LAKE HURON
SHORELINE TO THE LAKE MICHIGAN SHORELINE. DID EXTEND THE ADVISORY
FOR THE NEARSHORE WATERS SOUTH OF STURGEON POINT THROUGH
TODAY...AND MAY NEED TO EXTEND FURTHER INTO TUESDAY EVENING.
CHILLY AND OCCASIONALLY GUSTY WILL BE THE THEME THROUGH THE WEEK.
WAVES MAY STAY CHOPPY ENOUGH ON LAKE MICHIGAN FOR
ADDITIONAL/EXTENDED ADVISORIES.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LHZ349.

LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LMZ323-342-
     344>346.

LS...NONE.
&&

$$

NEAR TERM...SMD
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...SMD
MARINE...SMD



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000
FXUS63 KDTX 210350
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1150 PM EDT MON APR 20 2015


.AVIATION...

CEILINGS HEIGHTS UPSTREAM HAVE BEEN LIFTING AS DRIER AIR PUSHES INTO
THE AREA IN THE WAKE OF THIS EVENINGS LIGHT RAIN SHOWERS. A POOL OF
DEEPER COLD AIR WILL OVERSPREAD SRN MI TONIGHT. THIS WILL LIFT
INVERSION BASES AND TOGETHER WITH THE DRIER AIR WILL MAINTAIN VFR
CEILINGS INTO THE AFTERNOON. WINDS SPEEDS WILL CONTINUE TO DECREASE
DURING THE EARLY MORNING UNDER CONTINUED COOLING IN THE BOUNDARY
LAYER. RAPID DEEPENING OF THE DAYTIME MIXED LAYER AIDED BY THE DEPTH
OF THE COLD POOL ALOFT WILL LEAD TO STRONG SW WINDS LATE IN THE
MORNING THROUGH TUES AFTERNOON. THE CURRENT SET OF TAFS ACCOUNTS FOR
SOME POTENTIAL FOR STRONG CONVECTIVE WIND GUSTS OUT OF AFTERNOON
SHOWERS ON TUES...WHICH STILL LOOKS REASONABLE.

FOR DTW...THERE IS A CLEARING TREND NOTED UPSTREAM WHICH WILL LIKELY
MAKE INROADS INTO METRO PRIOR TO DAYBREAK. WITH THE LIFTING
INVERSION HEIGHTS AND THIS DRIER AIR...LINGERING CEILINGS AT OR
BELOW 5000 FT SHOULD BE LIMITED. WINDS SHOULD INCREASE RATHER
DRAMATICALLY WITH THE ONSET OF DAYTIME HEATING...ROUGHLY AROUND 14Z.

//DTW THRESHOLD PROBABILITIES...

* LOW IN CEILINGS AT OR BELOW 5000 FT THIS MORNING AND AFTERNOON.

* LOW IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS TUESDAY
  AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 1003 PM EDT MON APR 20 2015

UPDATE...

A BAND OF LIGHT SHOWERS WILL CONTINUE TO LIFT NORTHEAST ACROSS
MAINLY THE NORTHERN HALF OF THE FORECAST AREA THROUGH 06Z. THESE
SHOWERS ARE ASSOCIATED WITH A MID LEVEL SHORT WAVE FEATURE SHOWN
ON THE WATER VAPOR LOOP NOW ROTATING ACROSS SRN MI. THE FORCING
HAS BEEN WEAKENING SUBSTANTIALLY OVER SE MI...SO THE REMAINING
SHOWERS HAVE BEEN VERY LIGHT. THE OVERALL TREND WITH THE FORECAST
OF DECREASING COVERAGE OF SHOWERS OVERNIGHT LOOKS GOOD AS THE
FORCING EXITS TO THE NE OVER THE NEXT 2 TO 4 HOURS. A LITTLE BIT
OF SUBSIDENCE IN THE WAKE OF THIS FEATURE HAS BEEN PROMOTING SOME
CLEARING ACROSS NRN IL/FAR SRN LAKE MI. A LITTLE BETTER RESERVOIR
OF LOW LEVEL MOISTURE SHOULD KEEP CONDITIONS MOSTLY CLOUDY ACROSS
THE NRN HALF OF THE FORECAST AREA THROUGH THE NIGHT. SOUTH OF I-69
HOWEVER...CURRENT SATELLITE TRENDS DO SUGGEST SOME POSSIBLE
CLEARING LATE TONIGHT. AN UPDATE WILL BE ISSUED TO FURTHER LOWER
POPS AFTER 06Z AND DECREASE OVERNIGHT CLOUD COVERAGE ACROSS THE
SRN HALF OF THE FORECAST AREA.

PREV DISCUSSION...ISSUED 346 PM EDT MON APR 20 2015

SHORT TERM...TONIGHT

MUCAPES DID REACH 500 TO 800 J/KG EARLIER THIS AFTERNOON (PER LAPS
DATA)...WHICH WAS ABLE TO SUPPORT A COUPLE THUNDERSTORMS OVER
SOUTHEAST MICHIGAN. BULK OF CONVECTIVE ACTIVITY HAS PUSHED
EAST...AND CONTINUED DRYING BEHIND THE COLD FRONT WILL OCCUR...AS
SURFACE DEW PTS CRASH INTO THE 40S. WITH THAT COLDER/DRY AIR PUSH
IS SOME GUSTY WINDS...AS SOME PEAK WINDS OF 35 TO 45 MPH CAN BE
EXPECTED FOR ANOTHER COUPLE OF HOURS AS WE EXIT PEAK HEATING.
NOTED PEAK WIND AT DTW OF 42 KNOTS AT 1855Z. NAM/GFS MODEL
SOUNDINGS/LOW LEVEL RH FIELDS SUGGEST WE ARE GOING TO PARTIALLY
CLEAR OUT TONIGHT...BUT UPSTREAM OBSERVATIONS EXTENDING BACK WEST
OVER THE WESTERN GREAT LAKES/UPPER MISSISSIPPI RIVER VALLEY TO NOT
LOOK VERY ENCOURAGING...AND PREFERENCE WAS TO INCREASE THE CLOUD
COVER FORECAST FOR TONIGHT WITH THE COLD CYCLONIC FLOW. ALSO...AS
850 MB TEMPS FALL INTO THE MID NEGATIVE SINGLE NUMBERS OVER LAKE
MICHIGAN...SOME LAKE MICHIGAN MOISTURE/INSTABILITY CONTRIBUTION IS
NOT OUT OF THE QUESTION. HAVE CARRIED ISOLATED-SCATTERED LIGHT
RAIN SHOWER MENTION TO ACCOUNT FOR LINGERING ACTIVITY LATE THIS
AFTERNOON/EARLY THIS EVENING AND THEN THE POSSIBLE ACTIVITY TOWARD
MORNING. DESPITE CLOUDS...COLD ADVECTION EXPECTED TO SEND MINS
INTO THE UPPER 30S TO LOWER 40S.

LONG TERM...

A BROAD UPPER LEVEL TROUGH WITH A CLOSED LOW IN CLOSE PROXIMITY TO
THE GREAT LAKES REGION WILL KEEP SOUTHEASTERN MICHIGAN UNDER THE
INFLUENCE OF COLD CYCLONIC FLOW THROUGHOUT THE MIDWEEK PERIOD.
NATURE OF INDIVIDUAL SHORTWAVES ROTATING AROUND THIS UPPER LEVEL
FEATURE KEEPS THE SPECIFIC TIMING CONFIDENCE INHERENTLY LOW.

MAGNITUDE OF COLD AND DRY AIR ADVECTION FROM TONIGHT WILL
PRECONDITION THE ATMOSPHERE AND ALLOW FOR THE GROWTH OF A DEEP
DIURNAL NEAR SURFACE MIXED LAYER ON TUESDAY. FORECAST SOUNDINGS
SUGGEST MIXING HEIGHTS REACHING AS HIGH AS 6 TO 7 KFT AGL BY THE
AFTERNOON HOURS. GEOSTROPHIC FLOW IN THE REGION WILL REMAIN ELEVATED
WITH THE LOW HEIGHT ANOMALY OVER CENTRAL ONTARIO WHICH SUPPORTS
WIDESPREAD WESTERLY WIND GUSTS LATE TUESDAY MORNING/TUESDAY
AFTERNOON IN EXCESS OF 30 KNOTS. COMBINATION OF SHORTWAVE ENERGY
WORKING THROUGH THE TROUGH AXIS AND SPOKES OF ENHANCED MIDLEVEL
CONVERGENCE/SATURATION WILL BRING THE POTENTIAL FOR RAIN SHOWERS BY
TUESDAY MORNING. POTENTIAL MEDIUM IMPACT WEATHER SCENARIO MAY
UNFOLD...CONTINGENT ON OVERALL EFFICIENCY OF INDIVIDUAL CONVECTIVE
CIRCULATIONS OF THE SHOWERS TO ENHANCE DOWNWARD MOMENTUM TRANSPORT.
AFOREMENTIONED FORECAST DISCUSSION MADE REFERENCE TO A CLASSIC
INVERTED V STRUCTURE...WHICH SUGGESTS SOME POSSIBILITY THAT
WINDGUSTS COULD REACH 50 MPH. FUTURE SHIFTS CAN ASSESS THE
FEASIBILITY OF A POSSIBLE WIND ADVISORY FOR WEDNESDAY AFTERNOON.

PERSISTENT CYCLONIC FLOW AROUND UPPER LEVEL CLOSED LOW WILL BRING
ANOTHER DAY OF COLD AND SHOWERY TO SOUTHEASTERN MICHIGAN ON
WEDNESDAY. A SECONDARY SURGE OF COLD AIR ADVECTION IS FORECASTED
BETWEEN 15-18Z. THE CAA SHOULD WORK AGAINST DIURNAL HEATING...WITH
HIGHS SOME 7 TO 10 DEGREES COOLER THAN THE DAY BEFORE. HIGHS ON
WEDNESDAY ARE ONLY EXPECTED TO REACH THE MIDDLE TO UPPER 40S. BETTER
MESSAGE TO COMMUNICATE IS THAT WIND CHILLS FOR MANY AREAS WILL NOT
CLIMB OUT OF THE 30S.

THE REGION WILL STILL BE UNDER THE INFLUENCE OF LONGWAVE TROUGHING
ON THURSDAY BEFORE WEAK UPPER LEVEL RIDGING BUILDS IN FOR THE START
OF THE WEEKEND.  THIS TROUGH WILL CONTINUE TO LEAD TO COOLER TEMPS
THURSDAY BEFORE TEMPERATURES MODERATE A TINY BIT BACK INTO THE 50S
BY THE WEEKEND.  AT THIS POINT THE ONLY POTENTIAL FOR POSSIBLE
PRECIP IN THE EXTENDED WOULD BE ON SATURDAY...ALTHOUGH MOST MODELS
ARE KEEPING THE BULK OF THE PRECIP SOUTH OF THE CWA WITH THE
EXCEPTION OF THE 12Z ECMWF.

MARINE...

STRONG SOUTHWESTERLY WIND FIELD IS NOW IN PLACE WITH WINDSPEEDS AREA
WIDE RANGING BETWEEN 25 AND 35 KNOTS. SMALL CRAFT ADVISORIES REMAIN
IN EFFECT FOR ALL NEARSHORE ZONES. BREEZY WESTERLY WINDS WILL
PERSIST THROUGH MIDWEEK AS CONDITIONS REMAIN RELATIVELY STATIC WITH
LOW PRESSURE PARKED OVER THE GREAT LAKES. ADDITIONAL SMALL CRAFT
ADVISORIES FOR WIND WILL LIKELY BE NEEDED ON TUESDAY AND POSSIBLY
ONCE MORE ON WEDNESDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LEZ444.

&&

$$

AVIATION.....SC
UPDATE.......SC
SHORT TERM...SF
LONG TERM....CB/SS
MARINE.......CB


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).


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000
FXUS63 KGRR 210349
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1149 PM EDT MON APR 20 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 PM EDT MON APR 20 2015

A STALLED STORM SYSTEM OVER THE NORTHERN GREAT LAKES WILL KEEP
SHOWERS AND UNSEASONABLY COLD WEATHER THROUGH A GOOD PART OF THIS
WEEK. THE SHOWERS MAY BE MIXED WITH SNOW OR TURN TO SNOW AT TIMES
TUESDAY NIGHT INTO THURSDAY. ANY ACCUMULATIONS WILL BE MINOR.
FREEZING TEMPERATURES ARE EXPECTED EACH MORNING STARTING ON
WEDNESDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 330 PM EDT MON APR 20 2015

THE MAIN ISSUES ARE THE PRECIPITATION THREAT...THE RISK FOR SNOW
TUESDAY NIGHT INTO WEDNESDAY NIGHT AND THE GUSTY WINDS TONIGHT INTO
WEDNESDAY. OUR STALLED LOW PRESSURE SYSTEM WILL CONTINUE BRING
COLDER AIR INTO THE REGION INTO WEDNESDAY. SHORTWAVES ROTATING
AROUND THE STALLED SYSTEM WILL KEEP SHOWERS GOING THROUGH THE
SHORT TERM. WITH THE LAKE TEMPERATURE NEAR 3C... AND 850 TEMPS
FALLING TO NEAR -8C.... THAT IS MARGINAL FOR LAKE EFFECT BUT GIVEN
THERE IS ENOUGH MOISTURE IN THE 950 TO 700 MB LAYER THROUGH THIS
TIME PERIOD SHOWERS WILL CONTINUE AS WELL AS GUSTY WINDS. BY
TUESDAY NIGHT IT GETS COLD ENOUGH FOR MIXER RAIN AND SNOW AND THAT
THREAT CONTINUES INTO WEDNESDAY NIGHT.

SOME NOTE WORTHY ASPECTS TO OUR STORM SYSTEM... BASED ON THE
WESTERN REGION ENSEMBLE SITUATIONAL AWARENESS TABLE... A LOW
PRESSURE SYSTEM AS DEEP AS THIS ONE IS (984 MB AT 8 AM THIS
MORNING) HAS A RETURN PERIOD THAT IS LESS FREQUENT THAN ONCE IN 30
YEARS. HAVING 850 MB TEMPERATURES FALL INTO THE -8C TO -10C RANGE
OVER WESTERN LOWER MICHIGAN AND LAKE MICHIGAN DURING AROUND THE
21ST AND 22ND OF APRIL OCCURS ONLY ONCE IN 5 YEARS. HAVING THE 700
MB TEMPERATURE BELOW -16C HAPPENS LESS THAN ONCE IN 10 YEARS. SO
MY POINT IS THIS EVENT IS ACTUALLY A RATHER RARE EVENT FOR THIS
TIME OF YEAR IN THE GREAT LAKES.

IT SHOULD BE NOTED THE COLD TEMPERATURES (925/850/700/500 MB) FORECAST
BY THE GFS...ECMWF..THE ENSEMBLES OF BOTH...THE GEFS AND NAEFS
HAVE VERY PERSISTENT RUN AFTER RUN FOR MORE THAN A WEEK. MY POINT
HERE IS WE CAN TRUST THAT IT REALLY WILL GET AS COLD AS WE ARE
FORECASTING IT TO BE. WHICH MEANS WHEN THE 850 TEMPS FALL BELOW -6C
TOMORROW EVENING... SNOW WILL BE MORE LIKELY THAN RAIN AS A
PRECIPITATION TYPE.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 330 PM EDT MON APR 20 2015

UNSEASONABLY COOL WEATHER WILL CONTINUE THURSDAY WITH THE UPPER
TROUGH AXIS IN PLACE OVER THE EASTERN GREAT LAKES REGION AND DEEP
CYCLONIC FLOW. SCATTERED RAIN SHOWERS WILL LINGER THURSDAY AND MAY
BE MIXED AT TIMES WITH WET SNOW FLAKES PARTICULARLY ACROSS HIGHER
ELEVATIONS OF OUR NORTHERN FCST AREA.

THE UPPER TROUGH WILL SHIFT FURTHER EAST THURSDAY NIGHT AS A SFC
RIDGE BEGINS TO BUILD IN. THIS WILL LIKELY SET THE STAGE FOR A
COLDER NIGHT DEPENDING ON EXTENT AND TIMING OF CLEARING AS THE RIDGE
BEGINS TO BUILD IN. THERE IS POTENTIAL FOR WIDESPREAD TEMPS IN THE
25 TO 30 DEGREE RANGE BY EARLY FRIDAY MORNING SO FROST/FREEZE ISSUES
ARE CERTAINLY A CONCERN FOR LATE WEEK.

THE SFC HIGH PRESSURE RIDGE WILL BRING FAIR BUT COOL WEATHER FRIDAY
INTO SATURDAY. MAX TEMPS BY FRIDAY SHOULD REACH THE UPPER 40S TO
LOWER 50S WITH MIN TEMPS FRIDAY NIGHT IN THE 20S TO AROUND 30
DEGREES. TEMPERATURES WILL UNDERGO A SLOW MODERATING TREND FOR THE
WEEKEND INTO EARLY NEXT WEEK WITH FAIR WX EXPECTED TO CONTINUE WITH
THE SFC RIDGE REMAINING IN CONTROL OF THE WX PATTERN.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1148 PM EDT MON APR 20 2015

FAIRLY HIGH CONFIDENCE THAT WE WILL STAY ABOVE FUEL ALTERNATES AND
MAY IN FACT EVEN REMAIN VFR THROUGH 12Z. EXPECT LIGHT RAIN TO
REDEVELOP LATE TUESDAY MORNING/EARLY AFTERNOON PRIMARILY AT
NORTHERN TERMINALS. EXPECT LITTLE VSBY RESTRICTIONS...BUT CIGS ARE
A BIT LESS CERTAIN. CURRENTLY ADVERTISE CIGS LOWERING TO AROUND
025 AREAWIDE BUT COULD SEE FUEL ALTS BELOW 020 REALIZED AT MKG AND
GRR.

&&

.MARINE...
ISSUED AT 330 PM EDT MON APR 20 2015

I EXTENDED THE AREA COVERED BY THE SCA TO COVER THE ENTIRE NEAR
SHORE. I ALSO CONTINUED IT THROUGH WEDNESDAY AFTERNOON. WITH OUR
SYSTEM STALLED OVER THE GREAT LAKES MOST OF THE WEEK WE WILL SEE A
CONTINUATION OF 15 TO 25 KNOT WINDS FROM THE SOUTHWEST INTO
TUESDAY THEN NORTHWEST TUESDAY NIGHT THROUGH A GOOD PART OF THE
REST OF THE WEEK.


&&

.HYDROLOGY...
ISSUED AT 1156 AM EDT MON APR 20 2015

WIDESPREAD RAINFALL THROUGH 8 AM THIS MORNING PRODUCED 0.50 TO 0.75
INCHES ACROSS MOST OF THE GRAND AND MUSKEGON RIVER BASINS. FURTHER
SOUTH ACROSS THE KALAMAZOO RIVER BASIN...RAINFALL AMOUNTS WERE
HIGHER IN THE 0.75 TO 1.00 INCH RANGE. AS EXPECTED...GRADUAL RIVER
RISES HAVE BEGUN ON MOST AREA RIVERS. GENERAL HYDRO THINKING HAS NOT
CHANGED MUCH...MOSTLY WITHIN BANK RISES ARE EXPECTED. A FEW SITES
COULD EXCEED BANKFULL. BUT WITH RAIN TODAY AND TONIGHT BEING OF THE
SCATTERED AND LIGHT VARIETY...SIGNIFICANT FLOODING IS NOT EXPECTED.

FORECAST RAINFALL TODAY AND TONIGHT IS IN THE 0.10 TO 0.25 INCH
RANGE. EVEN LIGHTER PRECIP AMOUNTS ARE EXPECTED TUESDAY
INTO WEDNESDAY. A SLIGHT CHANCE OF LIGHT RAIN AND SNOW WILL LINGER
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. BUT MAINLY DRY AND CHILLY
WEATHER IS EXPECTED TOWARD THE END OF THE WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...TJT
HYDROLOGY...EBW
MARINE...WDM







000
FXUS63 KDTX 210203
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1003 PM EDT MON APR 20 2015

.UPDATE...

A BAND OF LIGHT SHOWERS WILL CONTINUE TO LIFT NORTHEAST ACROSS
MAINLY THE NORTHERN HALF OF THE FORECAST AREA THROUGH 06Z. THESE
SHOWERS ARE ASSOCIATED WITH A MID LEVEL SHORT WAVE FEATURE SHOWN
ON THE WATER VAPOR LOOP NOW ROTATING ACROSS SRN MI. THE FORCING
HAS BEEN WEAKENING SUBSTANTIALLY OVER SE MI...SO THE REMAINING
SHOWERS HAVE BEEN VERY LIGHT. THE OVERALL TREND WITH THE FORECAST
OF DECREASING COVERAGE OF SHOWERS OVERNIGHT LOOKS GOOD AS THE
FORCING EXITS TO THE NE OVER THE NEXT 2 TO 4 HOURS. A LITTLE BIT
OF SUBSIDENCE IN THE WAKE OF THIS FEATURE HAS BEEN PROMOTING SOME
CLEARING ACROSS NRN IL/FAR SRN LAKE MI. A LITTLE BETTER RESERVOIR
OF LOW LEVEL MOISTURE SHOULD KEEP CONDITIONS MOSTLY CLOUDY ACROSS
THE NRN HALF OF THE FORECAST AREA THROUGH THE NIGHT. SOUTH OF I-69
HOWEVER...CURRENT SATELLITE TRENDS DO SUGGEST SOME POSSIBLE
CLEARING LATE TONIGHT. AN UPDATE WILL BE ISSUED TO FURTHER LOWER
POPS AFTER 06Z AND DECREASE OVERNIGHT CLOUD COVERAGE ACROSS THE
SRN HALF OF THE FORECAST AREA.

&&

.AVIATION...ISSUED 702 PM EDT MON APR 20 2015

THERE HAS BEEN SOME SLIGHT DECREASE IN WIND SPEEDS OVER THE LAST
COUPLE OF HOURS. ONGOING LOW LEVEL COLD AIR ADVECTION SHOULD KEEP
SOME DEGREE OF GUSTINESS TO THE WINDS DURING THE FIRST HOUR OR TWO
OF THE TAF FORECAST. THERE SHOULD THEN BE SOME DEGREE OF DECOUPLING
IN THE BOUNDARY LAYER DURING THE EVENING WHICH WILL DECREASE WIND
SPEEDS FURTHER AND HELP SUPPRESS SOME OF THE GUSTINESS. AN AXIS OF
LOW LEVEL MOISTURE WILL TRACK ACROSS SE MI THIS EVENING...SUSTAINING
SOME RESIDUAL LIGHT SHOWERS AND MVFR BASED CEILINGS. CEILINGS WILL
LIFT DURING THE OVERNIGHT AS THE DEPTH OF COLD AIR DRAMATICALLY
INCREASES ACROSS SRN MI. RAPID DEEPENING OF THE DAYTIME MIXED LAYER
WILL LEAD TO STRONG SW WINDS LATE TUES MORNING THROUGH TUES
AFTERNOON. THE CURRENT SET OF OF TAFS ACCOUNTS FOR SOME POTENTIAL
FOR STRONG CONVECTIVE WIND GUSTS OUT OF AFTERNOON SHOWERS ON TUES.
THIS STILL LOOKS REASONABLE.

FOR DTW...IN LIGHT OF CURRENT OBSERVATIONS...THERE IS A CHANCE THAT
CEILINGS WILL DROP BELOW 2K FT BRIEFLY THIS EVENING. THE BETTER LOW
LEVEL MOISTURE WILL LIFT NORTH OF METRO OVERNIGHT...POSSIBLY OPENING
THE DOOR FOR SOME BRIEF CLEARING TOWARD DAYBREAK. CONFIDENCE OF THIS
IS NOT HIGH ENOUGH TO ADD A PERIOD OF CLEAR SKIES ATTM.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS BELOW 5000 FT THIS EVENING. LOW OVERNIGHT AND
  TUESDAY.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS TUESDAY
  AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 346 PM EDT MON APR 20 2015

SHORT TERM...TONIGHT

MUCAPES DID REACH 500 TO 800 J/KG EARLIER THIS AFTERNOON (PER LAPS
DATA)...WHICH WAS ABLE TO SUPPORT A COUPLE THUNDERSTORMS OVER
SOUTHEAST MICHIGAN. BULK OF CONVECTIVE ACTIVITY HAS PUSHED
EAST...AND CONTINUED DRYING BEHIND THE COLD FRONT WILL OCCUR...AS
SURFACE DEW PTS CRASH INTO THE 40S. WITH THAT COLDER/DRY AIR PUSH
IS SOME GUSTY WINDS...AS SOME PEAK WINDS OF 35 TO 45 MPH CAN BE
EXPECTED FOR ANOTHER COUPLE OF HOURS AS WE EXIT PEAK HEATING.
NOTED PEAK WIND AT DTW OF 42 KNOTS AT 1855Z. NAM/GFS MODEL
SOUNDINGS/LOW LEVEL RH FIELDS SUGGEST WE ARE GOING TO PARTIALLY
CLEAR OUT TONIGHT...BUT UPSTREAM OBSERVATIONS EXTENDING BACK WEST
OVER THE WESTERN GREAT LAKES/UPPER MISSISSIPPI RIVER VALLEY TO NOT
LOOK VERY ENCOURAGING...AND PREFERENCE WAS TO INCREASE THE CLOUD
COVER FORECAST FOR TONIGHT WITH THE COLD CYCLONIC FLOW. ALSO...AS
850 MB TEMPS FALL INTO THE MID NEGATIVE SINGLE NUMBERS OVER LAKE
MICHIGAN...SOME LAKE MICHIGAN MOISTURE/INSTABILITY CONTRIBUTION IS
NOT OUT OF THE QUESTION. HAVE CARRIED ISOLATED-SCATTERED LIGHT
RAIN SHOWER MENTION TO ACCOUNT FOR LINGERING ACTIVITY LATE THIS
AFTERNOON/EARLY THIS EVENING AND THEN THE POSSIBLE ACTIVITY TOWARD
MORNING. DESPITE CLOUDS...COLD ADVECTION EXPECTED TO SEND MINS
INTO THE UPPER 30S TO LOWER 40S.

LONG TERM...

A BROAD UPPER LEVEL TROUGH WITH A CLOSED LOW IN CLOSE PROXIMITY TO
THE GREAT LAKES REGION WILL KEEP SOUTHEASTERN MICHIGAN UNDER THE
INFLUENCE OF COLD CYCLONIC FLOW THROUGHOUT THE MIDWEEK PERIOD.
NATURE OF INDIVIDUAL SHORTWAVES ROTATING AROUND THIS UPPER LEVEL
FEATURE KEEPS THE SPECIFIC TIMING CONFIDENCE INHERENTLY LOW.

MAGNITUDE OF COLD AND DRY AIR ADVECTION FROM TONIGHT WILL
PRECONDITION THE ATMOSPHERE AND ALLOW FOR THE GROWTH OF A DEEP
DIURNAL NEAR SURFACE MIXED LAYER ON TUESDAY. FORECAST SOUNDINGS
SUGGEST MIXING HEIGHTS REACHING AS HIGH AS 6 TO 7 KFT AGL BY THE
AFTERNOON HOURS. GEOSTROPHIC FLOW IN THE REGION WILL REMAIN ELEVATED
WITH THE LOW HEIGHT ANOMALY OVER CENTRAL ONTARIO WHICH SUPPORTS
WIDESPREAD WESTERLY WIND GUSTS LATE TUESDAY MORNING/TUESDAY
AFTERNOON IN EXCESS OF 30 KNOTS. COMBINATION OF SHORTWAVE ENERGY
WORKING THROUGH THE TROUGH AXIS AND SPOKES OF ENHANCED MIDLEVEL
CONVERGENCE/SATURATION WILL BRING THE POTENTIAL FOR RAIN SHOWERS BY
TUESDAY MORNING. POTENTIAL MEDIUM IMPACT WEATHER SCENARIO MAY
UNFOLD...CONTINGENT ON OVERALL EFFICIENCY OF INDIVIDUAL CONVECTIVE
CIRCULATIONS OF THE SHOWERS TO ENHANCE DOWNWARD MOMENTUM TRANSPORT.
AFOREMENTIONED FORECAST DISCUSSION MADE REFERENCE TO A CLASSIC
INVERTED V STRUCTURE...WHICH SUGGESTS SOME POSSIBILITY THAT
WINDGUSTS COULD REACH 50 MPH. FUTURE SHIFTS CAN ASSESS THE
FEASIBILITY OF A POSSIBLE WIND ADVISORY FOR WEDNESDAY AFTERNOON.

PERSISTENT CYCLONIC FLOW AROUND UPPER LEVEL CLOSED LOW WILL BRING
ANOTHER DAY OF COLD AND SHOWERY TO SOUTHEASTERN MICHIGAN ON
WEDNESDAY. A SECONDARY SURGE OF COLD AIR ADVECTION IS FORECASTED
BETWEEN 15-18Z. THE CAA SHOULD WORK AGAINST DIURNAL HEATING...WITH
HIGHS SOME 7 TO 10 DEGREES COOLER THAN THE DAY BEFORE. HIGHS ON
WEDNESDAY ARE ONLY EXPECTED TO REACH THE MIDDLE TO UPPER 40S. BETTER
MESSAGE TO COMMUNICATE IS THAT WIND CHILLS FOR MANY AREAS WILL NOT
CLIMB OUT OF THE 30S.

THE REGION WILL STILL BE UNDER THE INFLUENCE OF LONGWAVE TROUGHING
ON THURSDAY BEFORE WEAK UPPER LEVEL RIDGING BUILDS IN FOR THE START
OF THE WEEKEND.  THIS TROUGH WILL CONTINUE TO LEAD TO COOLER TEMPS
THURSDAY BEFORE TEMPERATURES MODERATE A TINY BIT BACK INTO THE 50S
BY THE WEEKEND.  AT THIS POINT THE ONLY POTENTIAL FOR POSSIBLE
PRECIP IN THE EXTENDED WOULD BE ON SATURDAY...ALTHOUGH MOST MODELS
ARE KEEPING THE BULK OF THE PRECIP SOUTH OF THE CWA WITH THE
EXCEPTION OF THE 12Z ECMWF.

MARINE...

STRONG SOUTHWESTERLY WIND FIELD IS NOW IN PLACE WITH WINDSPEEDS AREA
WIDE RANGING BETWEEN 25 AND 35 KNOTS. SMALL CRAFT ADVISORIES REMAIN
IN EFFECT FOR ALL NEARSHORE ZONES. BREEZY WESTERLY WINDS WILL
PERSIST THROUGH MIDWEEK AS CONDITIONS REMAIN RELATIVELY STATIC WITH
LOW PRESSURE PARKED OVER THE GREAT LAKES. ADDITIONAL SMALL CRAFT
ADVISORIES FOR WIND WILL LIKELY BE NEEDED ON TUESDAY AND POSSIBLY
ONCE MORE ON WEDNESDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LEZ444.

&&

$$

UPDATE.......SC
AVIATION.....SC
SHORT TERM...SF
LONG TERM....CB/SS
MARINE.......CB


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).




000
FXUS63 KDTX 210203
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1003 PM EDT MON APR 20 2015

.UPDATE...

A BAND OF LIGHT SHOWERS WILL CONTINUE TO LIFT NORTHEAST ACROSS
MAINLY THE NORTHERN HALF OF THE FORECAST AREA THROUGH 06Z. THESE
SHOWERS ARE ASSOCIATED WITH A MID LEVEL SHORT WAVE FEATURE SHOWN
ON THE WATER VAPOR LOOP NOW ROTATING ACROSS SRN MI. THE FORCING
HAS BEEN WEAKENING SUBSTANTIALLY OVER SE MI...SO THE REMAINING
SHOWERS HAVE BEEN VERY LIGHT. THE OVERALL TREND WITH THE FORECAST
OF DECREASING COVERAGE OF SHOWERS OVERNIGHT LOOKS GOOD AS THE
FORCING EXITS TO THE NE OVER THE NEXT 2 TO 4 HOURS. A LITTLE BIT
OF SUBSIDENCE IN THE WAKE OF THIS FEATURE HAS BEEN PROMOTING SOME
CLEARING ACROSS NRN IL/FAR SRN LAKE MI. A LITTLE BETTER RESERVOIR
OF LOW LEVEL MOISTURE SHOULD KEEP CONDITIONS MOSTLY CLOUDY ACROSS
THE NRN HALF OF THE FORECAST AREA THROUGH THE NIGHT. SOUTH OF I-69
HOWEVER...CURRENT SATELLITE TRENDS DO SUGGEST SOME POSSIBLE
CLEARING LATE TONIGHT. AN UPDATE WILL BE ISSUED TO FURTHER LOWER
POPS AFTER 06Z AND DECREASE OVERNIGHT CLOUD COVERAGE ACROSS THE
SRN HALF OF THE FORECAST AREA.

&&

.AVIATION...ISSUED 702 PM EDT MON APR 20 2015

THERE HAS BEEN SOME SLIGHT DECREASE IN WIND SPEEDS OVER THE LAST
COUPLE OF HOURS. ONGOING LOW LEVEL COLD AIR ADVECTION SHOULD KEEP
SOME DEGREE OF GUSTINESS TO THE WINDS DURING THE FIRST HOUR OR TWO
OF THE TAF FORECAST. THERE SHOULD THEN BE SOME DEGREE OF DECOUPLING
IN THE BOUNDARY LAYER DURING THE EVENING WHICH WILL DECREASE WIND
SPEEDS FURTHER AND HELP SUPPRESS SOME OF THE GUSTINESS. AN AXIS OF
LOW LEVEL MOISTURE WILL TRACK ACROSS SE MI THIS EVENING...SUSTAINING
SOME RESIDUAL LIGHT SHOWERS AND MVFR BASED CEILINGS. CEILINGS WILL
LIFT DURING THE OVERNIGHT AS THE DEPTH OF COLD AIR DRAMATICALLY
INCREASES ACROSS SRN MI. RAPID DEEPENING OF THE DAYTIME MIXED LAYER
WILL LEAD TO STRONG SW WINDS LATE TUES MORNING THROUGH TUES
AFTERNOON. THE CURRENT SET OF OF TAFS ACCOUNTS FOR SOME POTENTIAL
FOR STRONG CONVECTIVE WIND GUSTS OUT OF AFTERNOON SHOWERS ON TUES.
THIS STILL LOOKS REASONABLE.

FOR DTW...IN LIGHT OF CURRENT OBSERVATIONS...THERE IS A CHANCE THAT
CEILINGS WILL DROP BELOW 2K FT BRIEFLY THIS EVENING. THE BETTER LOW
LEVEL MOISTURE WILL LIFT NORTH OF METRO OVERNIGHT...POSSIBLY OPENING
THE DOOR FOR SOME BRIEF CLEARING TOWARD DAYBREAK. CONFIDENCE OF THIS
IS NOT HIGH ENOUGH TO ADD A PERIOD OF CLEAR SKIES ATTM.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS BELOW 5000 FT THIS EVENING. LOW OVERNIGHT AND
  TUESDAY.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS TUESDAY
  AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 346 PM EDT MON APR 20 2015

SHORT TERM...TONIGHT

MUCAPES DID REACH 500 TO 800 J/KG EARLIER THIS AFTERNOON (PER LAPS
DATA)...WHICH WAS ABLE TO SUPPORT A COUPLE THUNDERSTORMS OVER
SOUTHEAST MICHIGAN. BULK OF CONVECTIVE ACTIVITY HAS PUSHED
EAST...AND CONTINUED DRYING BEHIND THE COLD FRONT WILL OCCUR...AS
SURFACE DEW PTS CRASH INTO THE 40S. WITH THAT COLDER/DRY AIR PUSH
IS SOME GUSTY WINDS...AS SOME PEAK WINDS OF 35 TO 45 MPH CAN BE
EXPECTED FOR ANOTHER COUPLE OF HOURS AS WE EXIT PEAK HEATING.
NOTED PEAK WIND AT DTW OF 42 KNOTS AT 1855Z. NAM/GFS MODEL
SOUNDINGS/LOW LEVEL RH FIELDS SUGGEST WE ARE GOING TO PARTIALLY
CLEAR OUT TONIGHT...BUT UPSTREAM OBSERVATIONS EXTENDING BACK WEST
OVER THE WESTERN GREAT LAKES/UPPER MISSISSIPPI RIVER VALLEY TO NOT
LOOK VERY ENCOURAGING...AND PREFERENCE WAS TO INCREASE THE CLOUD
COVER FORECAST FOR TONIGHT WITH THE COLD CYCLONIC FLOW. ALSO...AS
850 MB TEMPS FALL INTO THE MID NEGATIVE SINGLE NUMBERS OVER LAKE
MICHIGAN...SOME LAKE MICHIGAN MOISTURE/INSTABILITY CONTRIBUTION IS
NOT OUT OF THE QUESTION. HAVE CARRIED ISOLATED-SCATTERED LIGHT
RAIN SHOWER MENTION TO ACCOUNT FOR LINGERING ACTIVITY LATE THIS
AFTERNOON/EARLY THIS EVENING AND THEN THE POSSIBLE ACTIVITY TOWARD
MORNING. DESPITE CLOUDS...COLD ADVECTION EXPECTED TO SEND MINS
INTO THE UPPER 30S TO LOWER 40S.

LONG TERM...

A BROAD UPPER LEVEL TROUGH WITH A CLOSED LOW IN CLOSE PROXIMITY TO
THE GREAT LAKES REGION WILL KEEP SOUTHEASTERN MICHIGAN UNDER THE
INFLUENCE OF COLD CYCLONIC FLOW THROUGHOUT THE MIDWEEK PERIOD.
NATURE OF INDIVIDUAL SHORTWAVES ROTATING AROUND THIS UPPER LEVEL
FEATURE KEEPS THE SPECIFIC TIMING CONFIDENCE INHERENTLY LOW.

MAGNITUDE OF COLD AND DRY AIR ADVECTION FROM TONIGHT WILL
PRECONDITION THE ATMOSPHERE AND ALLOW FOR THE GROWTH OF A DEEP
DIURNAL NEAR SURFACE MIXED LAYER ON TUESDAY. FORECAST SOUNDINGS
SUGGEST MIXING HEIGHTS REACHING AS HIGH AS 6 TO 7 KFT AGL BY THE
AFTERNOON HOURS. GEOSTROPHIC FLOW IN THE REGION WILL REMAIN ELEVATED
WITH THE LOW HEIGHT ANOMALY OVER CENTRAL ONTARIO WHICH SUPPORTS
WIDESPREAD WESTERLY WIND GUSTS LATE TUESDAY MORNING/TUESDAY
AFTERNOON IN EXCESS OF 30 KNOTS. COMBINATION OF SHORTWAVE ENERGY
WORKING THROUGH THE TROUGH AXIS AND SPOKES OF ENHANCED MIDLEVEL
CONVERGENCE/SATURATION WILL BRING THE POTENTIAL FOR RAIN SHOWERS BY
TUESDAY MORNING. POTENTIAL MEDIUM IMPACT WEATHER SCENARIO MAY
UNFOLD...CONTINGENT ON OVERALL EFFICIENCY OF INDIVIDUAL CONVECTIVE
CIRCULATIONS OF THE SHOWERS TO ENHANCE DOWNWARD MOMENTUM TRANSPORT.
AFOREMENTIONED FORECAST DISCUSSION MADE REFERENCE TO A CLASSIC
INVERTED V STRUCTURE...WHICH SUGGESTS SOME POSSIBILITY THAT
WINDGUSTS COULD REACH 50 MPH. FUTURE SHIFTS CAN ASSESS THE
FEASIBILITY OF A POSSIBLE WIND ADVISORY FOR WEDNESDAY AFTERNOON.

PERSISTENT CYCLONIC FLOW AROUND UPPER LEVEL CLOSED LOW WILL BRING
ANOTHER DAY OF COLD AND SHOWERY TO SOUTHEASTERN MICHIGAN ON
WEDNESDAY. A SECONDARY SURGE OF COLD AIR ADVECTION IS FORECASTED
BETWEEN 15-18Z. THE CAA SHOULD WORK AGAINST DIURNAL HEATING...WITH
HIGHS SOME 7 TO 10 DEGREES COOLER THAN THE DAY BEFORE. HIGHS ON
WEDNESDAY ARE ONLY EXPECTED TO REACH THE MIDDLE TO UPPER 40S. BETTER
MESSAGE TO COMMUNICATE IS THAT WIND CHILLS FOR MANY AREAS WILL NOT
CLIMB OUT OF THE 30S.

THE REGION WILL STILL BE UNDER THE INFLUENCE OF LONGWAVE TROUGHING
ON THURSDAY BEFORE WEAK UPPER LEVEL RIDGING BUILDS IN FOR THE START
OF THE WEEKEND.  THIS TROUGH WILL CONTINUE TO LEAD TO COOLER TEMPS
THURSDAY BEFORE TEMPERATURES MODERATE A TINY BIT BACK INTO THE 50S
BY THE WEEKEND.  AT THIS POINT THE ONLY POTENTIAL FOR POSSIBLE
PRECIP IN THE EXTENDED WOULD BE ON SATURDAY...ALTHOUGH MOST MODELS
ARE KEEPING THE BULK OF THE PRECIP SOUTH OF THE CWA WITH THE
EXCEPTION OF THE 12Z ECMWF.

MARINE...

STRONG SOUTHWESTERLY WIND FIELD IS NOW IN PLACE WITH WINDSPEEDS AREA
WIDE RANGING BETWEEN 25 AND 35 KNOTS. SMALL CRAFT ADVISORIES REMAIN
IN EFFECT FOR ALL NEARSHORE ZONES. BREEZY WESTERLY WINDS WILL
PERSIST THROUGH MIDWEEK AS CONDITIONS REMAIN RELATIVELY STATIC WITH
LOW PRESSURE PARKED OVER THE GREAT LAKES. ADDITIONAL SMALL CRAFT
ADVISORIES FOR WIND WILL LIKELY BE NEEDED ON TUESDAY AND POSSIBLY
ONCE MORE ON WEDNESDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LEZ444.

&&

$$

UPDATE.......SC
AVIATION.....SC
SHORT TERM...SF
LONG TERM....CB/SS
MARINE.......CB


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).




000
FXUS63 KDTX 210203
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1003 PM EDT MON APR 20 2015

.UPDATE...

A BAND OF LIGHT SHOWERS WILL CONTINUE TO LIFT NORTHEAST ACROSS
MAINLY THE NORTHERN HALF OF THE FORECAST AREA THROUGH 06Z. THESE
SHOWERS ARE ASSOCIATED WITH A MID LEVEL SHORT WAVE FEATURE SHOWN
ON THE WATER VAPOR LOOP NOW ROTATING ACROSS SRN MI. THE FORCING
HAS BEEN WEAKENING SUBSTANTIALLY OVER SE MI...SO THE REMAINING
SHOWERS HAVE BEEN VERY LIGHT. THE OVERALL TREND WITH THE FORECAST
OF DECREASING COVERAGE OF SHOWERS OVERNIGHT LOOKS GOOD AS THE
FORCING EXITS TO THE NE OVER THE NEXT 2 TO 4 HOURS. A LITTLE BIT
OF SUBSIDENCE IN THE WAKE OF THIS FEATURE HAS BEEN PROMOTING SOME
CLEARING ACROSS NRN IL/FAR SRN LAKE MI. A LITTLE BETTER RESERVOIR
OF LOW LEVEL MOISTURE SHOULD KEEP CONDITIONS MOSTLY CLOUDY ACROSS
THE NRN HALF OF THE FORECAST AREA THROUGH THE NIGHT. SOUTH OF I-69
HOWEVER...CURRENT SATELLITE TRENDS DO SUGGEST SOME POSSIBLE
CLEARING LATE TONIGHT. AN UPDATE WILL BE ISSUED TO FURTHER LOWER
POPS AFTER 06Z AND DECREASE OVERNIGHT CLOUD COVERAGE ACROSS THE
SRN HALF OF THE FORECAST AREA.

&&

.AVIATION...ISSUED 702 PM EDT MON APR 20 2015

THERE HAS BEEN SOME SLIGHT DECREASE IN WIND SPEEDS OVER THE LAST
COUPLE OF HOURS. ONGOING LOW LEVEL COLD AIR ADVECTION SHOULD KEEP
SOME DEGREE OF GUSTINESS TO THE WINDS DURING THE FIRST HOUR OR TWO
OF THE TAF FORECAST. THERE SHOULD THEN BE SOME DEGREE OF DECOUPLING
IN THE BOUNDARY LAYER DURING THE EVENING WHICH WILL DECREASE WIND
SPEEDS FURTHER AND HELP SUPPRESS SOME OF THE GUSTINESS. AN AXIS OF
LOW LEVEL MOISTURE WILL TRACK ACROSS SE MI THIS EVENING...SUSTAINING
SOME RESIDUAL LIGHT SHOWERS AND MVFR BASED CEILINGS. CEILINGS WILL
LIFT DURING THE OVERNIGHT AS THE DEPTH OF COLD AIR DRAMATICALLY
INCREASES ACROSS SRN MI. RAPID DEEPENING OF THE DAYTIME MIXED LAYER
WILL LEAD TO STRONG SW WINDS LATE TUES MORNING THROUGH TUES
AFTERNOON. THE CURRENT SET OF OF TAFS ACCOUNTS FOR SOME POTENTIAL
FOR STRONG CONVECTIVE WIND GUSTS OUT OF AFTERNOON SHOWERS ON TUES.
THIS STILL LOOKS REASONABLE.

FOR DTW...IN LIGHT OF CURRENT OBSERVATIONS...THERE IS A CHANCE THAT
CEILINGS WILL DROP BELOW 2K FT BRIEFLY THIS EVENING. THE BETTER LOW
LEVEL MOISTURE WILL LIFT NORTH OF METRO OVERNIGHT...POSSIBLY OPENING
THE DOOR FOR SOME BRIEF CLEARING TOWARD DAYBREAK. CONFIDENCE OF THIS
IS NOT HIGH ENOUGH TO ADD A PERIOD OF CLEAR SKIES ATTM.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS BELOW 5000 FT THIS EVENING. LOW OVERNIGHT AND
  TUESDAY.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS TUESDAY
  AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 346 PM EDT MON APR 20 2015

SHORT TERM...TONIGHT

MUCAPES DID REACH 500 TO 800 J/KG EARLIER THIS AFTERNOON (PER LAPS
DATA)...WHICH WAS ABLE TO SUPPORT A COUPLE THUNDERSTORMS OVER
SOUTHEAST MICHIGAN. BULK OF CONVECTIVE ACTIVITY HAS PUSHED
EAST...AND CONTINUED DRYING BEHIND THE COLD FRONT WILL OCCUR...AS
SURFACE DEW PTS CRASH INTO THE 40S. WITH THAT COLDER/DRY AIR PUSH
IS SOME GUSTY WINDS...AS SOME PEAK WINDS OF 35 TO 45 MPH CAN BE
EXPECTED FOR ANOTHER COUPLE OF HOURS AS WE EXIT PEAK HEATING.
NOTED PEAK WIND AT DTW OF 42 KNOTS AT 1855Z. NAM/GFS MODEL
SOUNDINGS/LOW LEVEL RH FIELDS SUGGEST WE ARE GOING TO PARTIALLY
CLEAR OUT TONIGHT...BUT UPSTREAM OBSERVATIONS EXTENDING BACK WEST
OVER THE WESTERN GREAT LAKES/UPPER MISSISSIPPI RIVER VALLEY TO NOT
LOOK VERY ENCOURAGING...AND PREFERENCE WAS TO INCREASE THE CLOUD
COVER FORECAST FOR TONIGHT WITH THE COLD CYCLONIC FLOW. ALSO...AS
850 MB TEMPS FALL INTO THE MID NEGATIVE SINGLE NUMBERS OVER LAKE
MICHIGAN...SOME LAKE MICHIGAN MOISTURE/INSTABILITY CONTRIBUTION IS
NOT OUT OF THE QUESTION. HAVE CARRIED ISOLATED-SCATTERED LIGHT
RAIN SHOWER MENTION TO ACCOUNT FOR LINGERING ACTIVITY LATE THIS
AFTERNOON/EARLY THIS EVENING AND THEN THE POSSIBLE ACTIVITY TOWARD
MORNING. DESPITE CLOUDS...COLD ADVECTION EXPECTED TO SEND MINS
INTO THE UPPER 30S TO LOWER 40S.

LONG TERM...

A BROAD UPPER LEVEL TROUGH WITH A CLOSED LOW IN CLOSE PROXIMITY TO
THE GREAT LAKES REGION WILL KEEP SOUTHEASTERN MICHIGAN UNDER THE
INFLUENCE OF COLD CYCLONIC FLOW THROUGHOUT THE MIDWEEK PERIOD.
NATURE OF INDIVIDUAL SHORTWAVES ROTATING AROUND THIS UPPER LEVEL
FEATURE KEEPS THE SPECIFIC TIMING CONFIDENCE INHERENTLY LOW.

MAGNITUDE OF COLD AND DRY AIR ADVECTION FROM TONIGHT WILL
PRECONDITION THE ATMOSPHERE AND ALLOW FOR THE GROWTH OF A DEEP
DIURNAL NEAR SURFACE MIXED LAYER ON TUESDAY. FORECAST SOUNDINGS
SUGGEST MIXING HEIGHTS REACHING AS HIGH AS 6 TO 7 KFT AGL BY THE
AFTERNOON HOURS. GEOSTROPHIC FLOW IN THE REGION WILL REMAIN ELEVATED
WITH THE LOW HEIGHT ANOMALY OVER CENTRAL ONTARIO WHICH SUPPORTS
WIDESPREAD WESTERLY WIND GUSTS LATE TUESDAY MORNING/TUESDAY
AFTERNOON IN EXCESS OF 30 KNOTS. COMBINATION OF SHORTWAVE ENERGY
WORKING THROUGH THE TROUGH AXIS AND SPOKES OF ENHANCED MIDLEVEL
CONVERGENCE/SATURATION WILL BRING THE POTENTIAL FOR RAIN SHOWERS BY
TUESDAY MORNING. POTENTIAL MEDIUM IMPACT WEATHER SCENARIO MAY
UNFOLD...CONTINGENT ON OVERALL EFFICIENCY OF INDIVIDUAL CONVECTIVE
CIRCULATIONS OF THE SHOWERS TO ENHANCE DOWNWARD MOMENTUM TRANSPORT.
AFOREMENTIONED FORECAST DISCUSSION MADE REFERENCE TO A CLASSIC
INVERTED V STRUCTURE...WHICH SUGGESTS SOME POSSIBILITY THAT
WINDGUSTS COULD REACH 50 MPH. FUTURE SHIFTS CAN ASSESS THE
FEASIBILITY OF A POSSIBLE WIND ADVISORY FOR WEDNESDAY AFTERNOON.

PERSISTENT CYCLONIC FLOW AROUND UPPER LEVEL CLOSED LOW WILL BRING
ANOTHER DAY OF COLD AND SHOWERY TO SOUTHEASTERN MICHIGAN ON
WEDNESDAY. A SECONDARY SURGE OF COLD AIR ADVECTION IS FORECASTED
BETWEEN 15-18Z. THE CAA SHOULD WORK AGAINST DIURNAL HEATING...WITH
HIGHS SOME 7 TO 10 DEGREES COOLER THAN THE DAY BEFORE. HIGHS ON
WEDNESDAY ARE ONLY EXPECTED TO REACH THE MIDDLE TO UPPER 40S. BETTER
MESSAGE TO COMMUNICATE IS THAT WIND CHILLS FOR MANY AREAS WILL NOT
CLIMB OUT OF THE 30S.

THE REGION WILL STILL BE UNDER THE INFLUENCE OF LONGWAVE TROUGHING
ON THURSDAY BEFORE WEAK UPPER LEVEL RIDGING BUILDS IN FOR THE START
OF THE WEEKEND.  THIS TROUGH WILL CONTINUE TO LEAD TO COOLER TEMPS
THURSDAY BEFORE TEMPERATURES MODERATE A TINY BIT BACK INTO THE 50S
BY THE WEEKEND.  AT THIS POINT THE ONLY POTENTIAL FOR POSSIBLE
PRECIP IN THE EXTENDED WOULD BE ON SATURDAY...ALTHOUGH MOST MODELS
ARE KEEPING THE BULK OF THE PRECIP SOUTH OF THE CWA WITH THE
EXCEPTION OF THE 12Z ECMWF.

MARINE...

STRONG SOUTHWESTERLY WIND FIELD IS NOW IN PLACE WITH WINDSPEEDS AREA
WIDE RANGING BETWEEN 25 AND 35 KNOTS. SMALL CRAFT ADVISORIES REMAIN
IN EFFECT FOR ALL NEARSHORE ZONES. BREEZY WESTERLY WINDS WILL
PERSIST THROUGH MIDWEEK AS CONDITIONS REMAIN RELATIVELY STATIC WITH
LOW PRESSURE PARKED OVER THE GREAT LAKES. ADDITIONAL SMALL CRAFT
ADVISORIES FOR WIND WILL LIKELY BE NEEDED ON TUESDAY AND POSSIBLY
ONCE MORE ON WEDNESDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LEZ444.

&&

$$

UPDATE.......SC
AVIATION.....SC
SHORT TERM...SF
LONG TERM....CB/SS
MARINE.......CB


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).




000
FXUS63 KDTX 210203
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1003 PM EDT MON APR 20 2015

.UPDATE...

A BAND OF LIGHT SHOWERS WILL CONTINUE TO LIFT NORTHEAST ACROSS
MAINLY THE NORTHERN HALF OF THE FORECAST AREA THROUGH 06Z. THESE
SHOWERS ARE ASSOCIATED WITH A MID LEVEL SHORT WAVE FEATURE SHOWN
ON THE WATER VAPOR LOOP NOW ROTATING ACROSS SRN MI. THE FORCING
HAS BEEN WEAKENING SUBSTANTIALLY OVER SE MI...SO THE REMAINING
SHOWERS HAVE BEEN VERY LIGHT. THE OVERALL TREND WITH THE FORECAST
OF DECREASING COVERAGE OF SHOWERS OVERNIGHT LOOKS GOOD AS THE
FORCING EXITS TO THE NE OVER THE NEXT 2 TO 4 HOURS. A LITTLE BIT
OF SUBSIDENCE IN THE WAKE OF THIS FEATURE HAS BEEN PROMOTING SOME
CLEARING ACROSS NRN IL/FAR SRN LAKE MI. A LITTLE BETTER RESERVOIR
OF LOW LEVEL MOISTURE SHOULD KEEP CONDITIONS MOSTLY CLOUDY ACROSS
THE NRN HALF OF THE FORECAST AREA THROUGH THE NIGHT. SOUTH OF I-69
HOWEVER...CURRENT SATELLITE TRENDS DO SUGGEST SOME POSSIBLE
CLEARING LATE TONIGHT. AN UPDATE WILL BE ISSUED TO FURTHER LOWER
POPS AFTER 06Z AND DECREASE OVERNIGHT CLOUD COVERAGE ACROSS THE
SRN HALF OF THE FORECAST AREA.

&&

.AVIATION...ISSUED 702 PM EDT MON APR 20 2015

THERE HAS BEEN SOME SLIGHT DECREASE IN WIND SPEEDS OVER THE LAST
COUPLE OF HOURS. ONGOING LOW LEVEL COLD AIR ADVECTION SHOULD KEEP
SOME DEGREE OF GUSTINESS TO THE WINDS DURING THE FIRST HOUR OR TWO
OF THE TAF FORECAST. THERE SHOULD THEN BE SOME DEGREE OF DECOUPLING
IN THE BOUNDARY LAYER DURING THE EVENING WHICH WILL DECREASE WIND
SPEEDS FURTHER AND HELP SUPPRESS SOME OF THE GUSTINESS. AN AXIS OF
LOW LEVEL MOISTURE WILL TRACK ACROSS SE MI THIS EVENING...SUSTAINING
SOME RESIDUAL LIGHT SHOWERS AND MVFR BASED CEILINGS. CEILINGS WILL
LIFT DURING THE OVERNIGHT AS THE DEPTH OF COLD AIR DRAMATICALLY
INCREASES ACROSS SRN MI. RAPID DEEPENING OF THE DAYTIME MIXED LAYER
WILL LEAD TO STRONG SW WINDS LATE TUES MORNING THROUGH TUES
AFTERNOON. THE CURRENT SET OF OF TAFS ACCOUNTS FOR SOME POTENTIAL
FOR STRONG CONVECTIVE WIND GUSTS OUT OF AFTERNOON SHOWERS ON TUES.
THIS STILL LOOKS REASONABLE.

FOR DTW...IN LIGHT OF CURRENT OBSERVATIONS...THERE IS A CHANCE THAT
CEILINGS WILL DROP BELOW 2K FT BRIEFLY THIS EVENING. THE BETTER LOW
LEVEL MOISTURE WILL LIFT NORTH OF METRO OVERNIGHT...POSSIBLY OPENING
THE DOOR FOR SOME BRIEF CLEARING TOWARD DAYBREAK. CONFIDENCE OF THIS
IS NOT HIGH ENOUGH TO ADD A PERIOD OF CLEAR SKIES ATTM.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS BELOW 5000 FT THIS EVENING. LOW OVERNIGHT AND
  TUESDAY.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS TUESDAY
  AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 346 PM EDT MON APR 20 2015

SHORT TERM...TONIGHT

MUCAPES DID REACH 500 TO 800 J/KG EARLIER THIS AFTERNOON (PER LAPS
DATA)...WHICH WAS ABLE TO SUPPORT A COUPLE THUNDERSTORMS OVER
SOUTHEAST MICHIGAN. BULK OF CONVECTIVE ACTIVITY HAS PUSHED
EAST...AND CONTINUED DRYING BEHIND THE COLD FRONT WILL OCCUR...AS
SURFACE DEW PTS CRASH INTO THE 40S. WITH THAT COLDER/DRY AIR PUSH
IS SOME GUSTY WINDS...AS SOME PEAK WINDS OF 35 TO 45 MPH CAN BE
EXPECTED FOR ANOTHER COUPLE OF HOURS AS WE EXIT PEAK HEATING.
NOTED PEAK WIND AT DTW OF 42 KNOTS AT 1855Z. NAM/GFS MODEL
SOUNDINGS/LOW LEVEL RH FIELDS SUGGEST WE ARE GOING TO PARTIALLY
CLEAR OUT TONIGHT...BUT UPSTREAM OBSERVATIONS EXTENDING BACK WEST
OVER THE WESTERN GREAT LAKES/UPPER MISSISSIPPI RIVER VALLEY TO NOT
LOOK VERY ENCOURAGING...AND PREFERENCE WAS TO INCREASE THE CLOUD
COVER FORECAST FOR TONIGHT WITH THE COLD CYCLONIC FLOW. ALSO...AS
850 MB TEMPS FALL INTO THE MID NEGATIVE SINGLE NUMBERS OVER LAKE
MICHIGAN...SOME LAKE MICHIGAN MOISTURE/INSTABILITY CONTRIBUTION IS
NOT OUT OF THE QUESTION. HAVE CARRIED ISOLATED-SCATTERED LIGHT
RAIN SHOWER MENTION TO ACCOUNT FOR LINGERING ACTIVITY LATE THIS
AFTERNOON/EARLY THIS EVENING AND THEN THE POSSIBLE ACTIVITY TOWARD
MORNING. DESPITE CLOUDS...COLD ADVECTION EXPECTED TO SEND MINS
INTO THE UPPER 30S TO LOWER 40S.

LONG TERM...

A BROAD UPPER LEVEL TROUGH WITH A CLOSED LOW IN CLOSE PROXIMITY TO
THE GREAT LAKES REGION WILL KEEP SOUTHEASTERN MICHIGAN UNDER THE
INFLUENCE OF COLD CYCLONIC FLOW THROUGHOUT THE MIDWEEK PERIOD.
NATURE OF INDIVIDUAL SHORTWAVES ROTATING AROUND THIS UPPER LEVEL
FEATURE KEEPS THE SPECIFIC TIMING CONFIDENCE INHERENTLY LOW.

MAGNITUDE OF COLD AND DRY AIR ADVECTION FROM TONIGHT WILL
PRECONDITION THE ATMOSPHERE AND ALLOW FOR THE GROWTH OF A DEEP
DIURNAL NEAR SURFACE MIXED LAYER ON TUESDAY. FORECAST SOUNDINGS
SUGGEST MIXING HEIGHTS REACHING AS HIGH AS 6 TO 7 KFT AGL BY THE
AFTERNOON HOURS. GEOSTROPHIC FLOW IN THE REGION WILL REMAIN ELEVATED
WITH THE LOW HEIGHT ANOMALY OVER CENTRAL ONTARIO WHICH SUPPORTS
WIDESPREAD WESTERLY WIND GUSTS LATE TUESDAY MORNING/TUESDAY
AFTERNOON IN EXCESS OF 30 KNOTS. COMBINATION OF SHORTWAVE ENERGY
WORKING THROUGH THE TROUGH AXIS AND SPOKES OF ENHANCED MIDLEVEL
CONVERGENCE/SATURATION WILL BRING THE POTENTIAL FOR RAIN SHOWERS BY
TUESDAY MORNING. POTENTIAL MEDIUM IMPACT WEATHER SCENARIO MAY
UNFOLD...CONTINGENT ON OVERALL EFFICIENCY OF INDIVIDUAL CONVECTIVE
CIRCULATIONS OF THE SHOWERS TO ENHANCE DOWNWARD MOMENTUM TRANSPORT.
AFOREMENTIONED FORECAST DISCUSSION MADE REFERENCE TO A CLASSIC
INVERTED V STRUCTURE...WHICH SUGGESTS SOME POSSIBILITY THAT
WINDGUSTS COULD REACH 50 MPH. FUTURE SHIFTS CAN ASSESS THE
FEASIBILITY OF A POSSIBLE WIND ADVISORY FOR WEDNESDAY AFTERNOON.

PERSISTENT CYCLONIC FLOW AROUND UPPER LEVEL CLOSED LOW WILL BRING
ANOTHER DAY OF COLD AND SHOWERY TO SOUTHEASTERN MICHIGAN ON
WEDNESDAY. A SECONDARY SURGE OF COLD AIR ADVECTION IS FORECASTED
BETWEEN 15-18Z. THE CAA SHOULD WORK AGAINST DIURNAL HEATING...WITH
HIGHS SOME 7 TO 10 DEGREES COOLER THAN THE DAY BEFORE. HIGHS ON
WEDNESDAY ARE ONLY EXPECTED TO REACH THE MIDDLE TO UPPER 40S. BETTER
MESSAGE TO COMMUNICATE IS THAT WIND CHILLS FOR MANY AREAS WILL NOT
CLIMB OUT OF THE 30S.

THE REGION WILL STILL BE UNDER THE INFLUENCE OF LONGWAVE TROUGHING
ON THURSDAY BEFORE WEAK UPPER LEVEL RIDGING BUILDS IN FOR THE START
OF THE WEEKEND.  THIS TROUGH WILL CONTINUE TO LEAD TO COOLER TEMPS
THURSDAY BEFORE TEMPERATURES MODERATE A TINY BIT BACK INTO THE 50S
BY THE WEEKEND.  AT THIS POINT THE ONLY POTENTIAL FOR POSSIBLE
PRECIP IN THE EXTENDED WOULD BE ON SATURDAY...ALTHOUGH MOST MODELS
ARE KEEPING THE BULK OF THE PRECIP SOUTH OF THE CWA WITH THE
EXCEPTION OF THE 12Z ECMWF.

MARINE...

STRONG SOUTHWESTERLY WIND FIELD IS NOW IN PLACE WITH WINDSPEEDS AREA
WIDE RANGING BETWEEN 25 AND 35 KNOTS. SMALL CRAFT ADVISORIES REMAIN
IN EFFECT FOR ALL NEARSHORE ZONES. BREEZY WESTERLY WINDS WILL
PERSIST THROUGH MIDWEEK AS CONDITIONS REMAIN RELATIVELY STATIC WITH
LOW PRESSURE PARKED OVER THE GREAT LAKES. ADDITIONAL SMALL CRAFT
ADVISORIES FOR WIND WILL LIKELY BE NEEDED ON TUESDAY AND POSSIBLY
ONCE MORE ON WEDNESDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LEZ444.

&&

$$

UPDATE.......SC
AVIATION.....SC
SHORT TERM...SF
LONG TERM....CB/SS
MARINE.......CB


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).




000
FXUS63 KDTX 210203
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1003 PM EDT MON APR 20 2015

.UPDATE...

A BAND OF LIGHT SHOWERS WILL CONTINUE TO LIFT NORTHEAST ACROSS
MAINLY THE NORTHERN HALF OF THE FORECAST AREA THROUGH 06Z. THESE
SHOWERS ARE ASSOCIATED WITH A MID LEVEL SHORT WAVE FEATURE SHOWN
ON THE WATER VAPOR LOOP NOW ROTATING ACROSS SRN MI. THE FORCING
HAS BEEN WEAKENING SUBSTANTIALLY OVER SE MI...SO THE REMAINING
SHOWERS HAVE BEEN VERY LIGHT. THE OVERALL TREND WITH THE FORECAST
OF DECREASING COVERAGE OF SHOWERS OVERNIGHT LOOKS GOOD AS THE
FORCING EXITS TO THE NE OVER THE NEXT 2 TO 4 HOURS. A LITTLE BIT
OF SUBSIDENCE IN THE WAKE OF THIS FEATURE HAS BEEN PROMOTING SOME
CLEARING ACROSS NRN IL/FAR SRN LAKE MI. A LITTLE BETTER RESERVOIR
OF LOW LEVEL MOISTURE SHOULD KEEP CONDITIONS MOSTLY CLOUDY ACROSS
THE NRN HALF OF THE FORECAST AREA THROUGH THE NIGHT. SOUTH OF I-69
HOWEVER...CURRENT SATELLITE TRENDS DO SUGGEST SOME POSSIBLE
CLEARING LATE TONIGHT. AN UPDATE WILL BE ISSUED TO FURTHER LOWER
POPS AFTER 06Z AND DECREASE OVERNIGHT CLOUD COVERAGE ACROSS THE
SRN HALF OF THE FORECAST AREA.

&&

.AVIATION...ISSUED 702 PM EDT MON APR 20 2015

THERE HAS BEEN SOME SLIGHT DECREASE IN WIND SPEEDS OVER THE LAST
COUPLE OF HOURS. ONGOING LOW LEVEL COLD AIR ADVECTION SHOULD KEEP
SOME DEGREE OF GUSTINESS TO THE WINDS DURING THE FIRST HOUR OR TWO
OF THE TAF FORECAST. THERE SHOULD THEN BE SOME DEGREE OF DECOUPLING
IN THE BOUNDARY LAYER DURING THE EVENING WHICH WILL DECREASE WIND
SPEEDS FURTHER AND HELP SUPPRESS SOME OF THE GUSTINESS. AN AXIS OF
LOW LEVEL MOISTURE WILL TRACK ACROSS SE MI THIS EVENING...SUSTAINING
SOME RESIDUAL LIGHT SHOWERS AND MVFR BASED CEILINGS. CEILINGS WILL
LIFT DURING THE OVERNIGHT AS THE DEPTH OF COLD AIR DRAMATICALLY
INCREASES ACROSS SRN MI. RAPID DEEPENING OF THE DAYTIME MIXED LAYER
WILL LEAD TO STRONG SW WINDS LATE TUES MORNING THROUGH TUES
AFTERNOON. THE CURRENT SET OF OF TAFS ACCOUNTS FOR SOME POTENTIAL
FOR STRONG CONVECTIVE WIND GUSTS OUT OF AFTERNOON SHOWERS ON TUES.
THIS STILL LOOKS REASONABLE.

FOR DTW...IN LIGHT OF CURRENT OBSERVATIONS...THERE IS A CHANCE THAT
CEILINGS WILL DROP BELOW 2K FT BRIEFLY THIS EVENING. THE BETTER LOW
LEVEL MOISTURE WILL LIFT NORTH OF METRO OVERNIGHT...POSSIBLY OPENING
THE DOOR FOR SOME BRIEF CLEARING TOWARD DAYBREAK. CONFIDENCE OF THIS
IS NOT HIGH ENOUGH TO ADD A PERIOD OF CLEAR SKIES ATTM.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS BELOW 5000 FT THIS EVENING. LOW OVERNIGHT AND
  TUESDAY.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS TUESDAY
  AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 346 PM EDT MON APR 20 2015

SHORT TERM...TONIGHT

MUCAPES DID REACH 500 TO 800 J/KG EARLIER THIS AFTERNOON (PER LAPS
DATA)...WHICH WAS ABLE TO SUPPORT A COUPLE THUNDERSTORMS OVER
SOUTHEAST MICHIGAN. BULK OF CONVECTIVE ACTIVITY HAS PUSHED
EAST...AND CONTINUED DRYING BEHIND THE COLD FRONT WILL OCCUR...AS
SURFACE DEW PTS CRASH INTO THE 40S. WITH THAT COLDER/DRY AIR PUSH
IS SOME GUSTY WINDS...AS SOME PEAK WINDS OF 35 TO 45 MPH CAN BE
EXPECTED FOR ANOTHER COUPLE OF HOURS AS WE EXIT PEAK HEATING.
NOTED PEAK WIND AT DTW OF 42 KNOTS AT 1855Z. NAM/GFS MODEL
SOUNDINGS/LOW LEVEL RH FIELDS SUGGEST WE ARE GOING TO PARTIALLY
CLEAR OUT TONIGHT...BUT UPSTREAM OBSERVATIONS EXTENDING BACK WEST
OVER THE WESTERN GREAT LAKES/UPPER MISSISSIPPI RIVER VALLEY TO NOT
LOOK VERY ENCOURAGING...AND PREFERENCE WAS TO INCREASE THE CLOUD
COVER FORECAST FOR TONIGHT WITH THE COLD CYCLONIC FLOW. ALSO...AS
850 MB TEMPS FALL INTO THE MID NEGATIVE SINGLE NUMBERS OVER LAKE
MICHIGAN...SOME LAKE MICHIGAN MOISTURE/INSTABILITY CONTRIBUTION IS
NOT OUT OF THE QUESTION. HAVE CARRIED ISOLATED-SCATTERED LIGHT
RAIN SHOWER MENTION TO ACCOUNT FOR LINGERING ACTIVITY LATE THIS
AFTERNOON/EARLY THIS EVENING AND THEN THE POSSIBLE ACTIVITY TOWARD
MORNING. DESPITE CLOUDS...COLD ADVECTION EXPECTED TO SEND MINS
INTO THE UPPER 30S TO LOWER 40S.

LONG TERM...

A BROAD UPPER LEVEL TROUGH WITH A CLOSED LOW IN CLOSE PROXIMITY TO
THE GREAT LAKES REGION WILL KEEP SOUTHEASTERN MICHIGAN UNDER THE
INFLUENCE OF COLD CYCLONIC FLOW THROUGHOUT THE MIDWEEK PERIOD.
NATURE OF INDIVIDUAL SHORTWAVES ROTATING AROUND THIS UPPER LEVEL
FEATURE KEEPS THE SPECIFIC TIMING CONFIDENCE INHERENTLY LOW.

MAGNITUDE OF COLD AND DRY AIR ADVECTION FROM TONIGHT WILL
PRECONDITION THE ATMOSPHERE AND ALLOW FOR THE GROWTH OF A DEEP
DIURNAL NEAR SURFACE MIXED LAYER ON TUESDAY. FORECAST SOUNDINGS
SUGGEST MIXING HEIGHTS REACHING AS HIGH AS 6 TO 7 KFT AGL BY THE
AFTERNOON HOURS. GEOSTROPHIC FLOW IN THE REGION WILL REMAIN ELEVATED
WITH THE LOW HEIGHT ANOMALY OVER CENTRAL ONTARIO WHICH SUPPORTS
WIDESPREAD WESTERLY WIND GUSTS LATE TUESDAY MORNING/TUESDAY
AFTERNOON IN EXCESS OF 30 KNOTS. COMBINATION OF SHORTWAVE ENERGY
WORKING THROUGH THE TROUGH AXIS AND SPOKES OF ENHANCED MIDLEVEL
CONVERGENCE/SATURATION WILL BRING THE POTENTIAL FOR RAIN SHOWERS BY
TUESDAY MORNING. POTENTIAL MEDIUM IMPACT WEATHER SCENARIO MAY
UNFOLD...CONTINGENT ON OVERALL EFFICIENCY OF INDIVIDUAL CONVECTIVE
CIRCULATIONS OF THE SHOWERS TO ENHANCE DOWNWARD MOMENTUM TRANSPORT.
AFOREMENTIONED FORECAST DISCUSSION MADE REFERENCE TO A CLASSIC
INVERTED V STRUCTURE...WHICH SUGGESTS SOME POSSIBILITY THAT
WINDGUSTS COULD REACH 50 MPH. FUTURE SHIFTS CAN ASSESS THE
FEASIBILITY OF A POSSIBLE WIND ADVISORY FOR WEDNESDAY AFTERNOON.

PERSISTENT CYCLONIC FLOW AROUND UPPER LEVEL CLOSED LOW WILL BRING
ANOTHER DAY OF COLD AND SHOWERY TO SOUTHEASTERN MICHIGAN ON
WEDNESDAY. A SECONDARY SURGE OF COLD AIR ADVECTION IS FORECASTED
BETWEEN 15-18Z. THE CAA SHOULD WORK AGAINST DIURNAL HEATING...WITH
HIGHS SOME 7 TO 10 DEGREES COOLER THAN THE DAY BEFORE. HIGHS ON
WEDNESDAY ARE ONLY EXPECTED TO REACH THE MIDDLE TO UPPER 40S. BETTER
MESSAGE TO COMMUNICATE IS THAT WIND CHILLS FOR MANY AREAS WILL NOT
CLIMB OUT OF THE 30S.

THE REGION WILL STILL BE UNDER THE INFLUENCE OF LONGWAVE TROUGHING
ON THURSDAY BEFORE WEAK UPPER LEVEL RIDGING BUILDS IN FOR THE START
OF THE WEEKEND.  THIS TROUGH WILL CONTINUE TO LEAD TO COOLER TEMPS
THURSDAY BEFORE TEMPERATURES MODERATE A TINY BIT BACK INTO THE 50S
BY THE WEEKEND.  AT THIS POINT THE ONLY POTENTIAL FOR POSSIBLE
PRECIP IN THE EXTENDED WOULD BE ON SATURDAY...ALTHOUGH MOST MODELS
ARE KEEPING THE BULK OF THE PRECIP SOUTH OF THE CWA WITH THE
EXCEPTION OF THE 12Z ECMWF.

MARINE...

STRONG SOUTHWESTERLY WIND FIELD IS NOW IN PLACE WITH WINDSPEEDS AREA
WIDE RANGING BETWEEN 25 AND 35 KNOTS. SMALL CRAFT ADVISORIES REMAIN
IN EFFECT FOR ALL NEARSHORE ZONES. BREEZY WESTERLY WINDS WILL
PERSIST THROUGH MIDWEEK AS CONDITIONS REMAIN RELATIVELY STATIC WITH
LOW PRESSURE PARKED OVER THE GREAT LAKES. ADDITIONAL SMALL CRAFT
ADVISORIES FOR WIND WILL LIKELY BE NEEDED ON TUESDAY AND POSSIBLY
ONCE MORE ON WEDNESDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LEZ444.

&&

$$

UPDATE.......SC
AVIATION.....SC
SHORT TERM...SF
LONG TERM....CB/SS
MARINE.......CB


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).



000
FXUS63 KDTX 210203
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1003 PM EDT MON APR 20 2015

.UPDATE...

A BAND OF LIGHT SHOWERS WILL CONTINUE TO LIFT NORTHEAST ACROSS
MAINLY THE NORTHERN HALF OF THE FORECAST AREA THROUGH 06Z. THESE
SHOWERS ARE ASSOCIATED WITH A MID LEVEL SHORT WAVE FEATURE SHOWN
ON THE WATER VAPOR LOOP NOW ROTATING ACROSS SRN MI. THE FORCING
HAS BEEN WEAKENING SUBSTANTIALLY OVER SE MI...SO THE REMAINING
SHOWERS HAVE BEEN VERY LIGHT. THE OVERALL TREND WITH THE FORECAST
OF DECREASING COVERAGE OF SHOWERS OVERNIGHT LOOKS GOOD AS THE
FORCING EXITS TO THE NE OVER THE NEXT 2 TO 4 HOURS. A LITTLE BIT
OF SUBSIDENCE IN THE WAKE OF THIS FEATURE HAS BEEN PROMOTING SOME
CLEARING ACROSS NRN IL/FAR SRN LAKE MI. A LITTLE BETTER RESERVOIR
OF LOW LEVEL MOISTURE SHOULD KEEP CONDITIONS MOSTLY CLOUDY ACROSS
THE NRN HALF OF THE FORECAST AREA THROUGH THE NIGHT. SOUTH OF I-69
HOWEVER...CURRENT SATELLITE TRENDS DO SUGGEST SOME POSSIBLE
CLEARING LATE TONIGHT. AN UPDATE WILL BE ISSUED TO FURTHER LOWER
POPS AFTER 06Z AND DECREASE OVERNIGHT CLOUD COVERAGE ACROSS THE
SRN HALF OF THE FORECAST AREA.

&&

.AVIATION...ISSUED 702 PM EDT MON APR 20 2015

THERE HAS BEEN SOME SLIGHT DECREASE IN WIND SPEEDS OVER THE LAST
COUPLE OF HOURS. ONGOING LOW LEVEL COLD AIR ADVECTION SHOULD KEEP
SOME DEGREE OF GUSTINESS TO THE WINDS DURING THE FIRST HOUR OR TWO
OF THE TAF FORECAST. THERE SHOULD THEN BE SOME DEGREE OF DECOUPLING
IN THE BOUNDARY LAYER DURING THE EVENING WHICH WILL DECREASE WIND
SPEEDS FURTHER AND HELP SUPPRESS SOME OF THE GUSTINESS. AN AXIS OF
LOW LEVEL MOISTURE WILL TRACK ACROSS SE MI THIS EVENING...SUSTAINING
SOME RESIDUAL LIGHT SHOWERS AND MVFR BASED CEILINGS. CEILINGS WILL
LIFT DURING THE OVERNIGHT AS THE DEPTH OF COLD AIR DRAMATICALLY
INCREASES ACROSS SRN MI. RAPID DEEPENING OF THE DAYTIME MIXED LAYER
WILL LEAD TO STRONG SW WINDS LATE TUES MORNING THROUGH TUES
AFTERNOON. THE CURRENT SET OF OF TAFS ACCOUNTS FOR SOME POTENTIAL
FOR STRONG CONVECTIVE WIND GUSTS OUT OF AFTERNOON SHOWERS ON TUES.
THIS STILL LOOKS REASONABLE.

FOR DTW...IN LIGHT OF CURRENT OBSERVATIONS...THERE IS A CHANCE THAT
CEILINGS WILL DROP BELOW 2K FT BRIEFLY THIS EVENING. THE BETTER LOW
LEVEL MOISTURE WILL LIFT NORTH OF METRO OVERNIGHT...POSSIBLY OPENING
THE DOOR FOR SOME BRIEF CLEARING TOWARD DAYBREAK. CONFIDENCE OF THIS
IS NOT HIGH ENOUGH TO ADD A PERIOD OF CLEAR SKIES ATTM.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS BELOW 5000 FT THIS EVENING. LOW OVERNIGHT AND
  TUESDAY.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS TUESDAY
  AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 346 PM EDT MON APR 20 2015

SHORT TERM...TONIGHT

MUCAPES DID REACH 500 TO 800 J/KG EARLIER THIS AFTERNOON (PER LAPS
DATA)...WHICH WAS ABLE TO SUPPORT A COUPLE THUNDERSTORMS OVER
SOUTHEAST MICHIGAN. BULK OF CONVECTIVE ACTIVITY HAS PUSHED
EAST...AND CONTINUED DRYING BEHIND THE COLD FRONT WILL OCCUR...AS
SURFACE DEW PTS CRASH INTO THE 40S. WITH THAT COLDER/DRY AIR PUSH
IS SOME GUSTY WINDS...AS SOME PEAK WINDS OF 35 TO 45 MPH CAN BE
EXPECTED FOR ANOTHER COUPLE OF HOURS AS WE EXIT PEAK HEATING.
NOTED PEAK WIND AT DTW OF 42 KNOTS AT 1855Z. NAM/GFS MODEL
SOUNDINGS/LOW LEVEL RH FIELDS SUGGEST WE ARE GOING TO PARTIALLY
CLEAR OUT TONIGHT...BUT UPSTREAM OBSERVATIONS EXTENDING BACK WEST
OVER THE WESTERN GREAT LAKES/UPPER MISSISSIPPI RIVER VALLEY TO NOT
LOOK VERY ENCOURAGING...AND PREFERENCE WAS TO INCREASE THE CLOUD
COVER FORECAST FOR TONIGHT WITH THE COLD CYCLONIC FLOW. ALSO...AS
850 MB TEMPS FALL INTO THE MID NEGATIVE SINGLE NUMBERS OVER LAKE
MICHIGAN...SOME LAKE MICHIGAN MOISTURE/INSTABILITY CONTRIBUTION IS
NOT OUT OF THE QUESTION. HAVE CARRIED ISOLATED-SCATTERED LIGHT
RAIN SHOWER MENTION TO ACCOUNT FOR LINGERING ACTIVITY LATE THIS
AFTERNOON/EARLY THIS EVENING AND THEN THE POSSIBLE ACTIVITY TOWARD
MORNING. DESPITE CLOUDS...COLD ADVECTION EXPECTED TO SEND MINS
INTO THE UPPER 30S TO LOWER 40S.

LONG TERM...

A BROAD UPPER LEVEL TROUGH WITH A CLOSED LOW IN CLOSE PROXIMITY TO
THE GREAT LAKES REGION WILL KEEP SOUTHEASTERN MICHIGAN UNDER THE
INFLUENCE OF COLD CYCLONIC FLOW THROUGHOUT THE MIDWEEK PERIOD.
NATURE OF INDIVIDUAL SHORTWAVES ROTATING AROUND THIS UPPER LEVEL
FEATURE KEEPS THE SPECIFIC TIMING CONFIDENCE INHERENTLY LOW.

MAGNITUDE OF COLD AND DRY AIR ADVECTION FROM TONIGHT WILL
PRECONDITION THE ATMOSPHERE AND ALLOW FOR THE GROWTH OF A DEEP
DIURNAL NEAR SURFACE MIXED LAYER ON TUESDAY. FORECAST SOUNDINGS
SUGGEST MIXING HEIGHTS REACHING AS HIGH AS 6 TO 7 KFT AGL BY THE
AFTERNOON HOURS. GEOSTROPHIC FLOW IN THE REGION WILL REMAIN ELEVATED
WITH THE LOW HEIGHT ANOMALY OVER CENTRAL ONTARIO WHICH SUPPORTS
WIDESPREAD WESTERLY WIND GUSTS LATE TUESDAY MORNING/TUESDAY
AFTERNOON IN EXCESS OF 30 KNOTS. COMBINATION OF SHORTWAVE ENERGY
WORKING THROUGH THE TROUGH AXIS AND SPOKES OF ENHANCED MIDLEVEL
CONVERGENCE/SATURATION WILL BRING THE POTENTIAL FOR RAIN SHOWERS BY
TUESDAY MORNING. POTENTIAL MEDIUM IMPACT WEATHER SCENARIO MAY
UNFOLD...CONTINGENT ON OVERALL EFFICIENCY OF INDIVIDUAL CONVECTIVE
CIRCULATIONS OF THE SHOWERS TO ENHANCE DOWNWARD MOMENTUM TRANSPORT.
AFOREMENTIONED FORECAST DISCUSSION MADE REFERENCE TO A CLASSIC
INVERTED V STRUCTURE...WHICH SUGGESTS SOME POSSIBILITY THAT
WINDGUSTS COULD REACH 50 MPH. FUTURE SHIFTS CAN ASSESS THE
FEASIBILITY OF A POSSIBLE WIND ADVISORY FOR WEDNESDAY AFTERNOON.

PERSISTENT CYCLONIC FLOW AROUND UPPER LEVEL CLOSED LOW WILL BRING
ANOTHER DAY OF COLD AND SHOWERY TO SOUTHEASTERN MICHIGAN ON
WEDNESDAY. A SECONDARY SURGE OF COLD AIR ADVECTION IS FORECASTED
BETWEEN 15-18Z. THE CAA SHOULD WORK AGAINST DIURNAL HEATING...WITH
HIGHS SOME 7 TO 10 DEGREES COOLER THAN THE DAY BEFORE. HIGHS ON
WEDNESDAY ARE ONLY EXPECTED TO REACH THE MIDDLE TO UPPER 40S. BETTER
MESSAGE TO COMMUNICATE IS THAT WIND CHILLS FOR MANY AREAS WILL NOT
CLIMB OUT OF THE 30S.

THE REGION WILL STILL BE UNDER THE INFLUENCE OF LONGWAVE TROUGHING
ON THURSDAY BEFORE WEAK UPPER LEVEL RIDGING BUILDS IN FOR THE START
OF THE WEEKEND.  THIS TROUGH WILL CONTINUE TO LEAD TO COOLER TEMPS
THURSDAY BEFORE TEMPERATURES MODERATE A TINY BIT BACK INTO THE 50S
BY THE WEEKEND.  AT THIS POINT THE ONLY POTENTIAL FOR POSSIBLE
PRECIP IN THE EXTENDED WOULD BE ON SATURDAY...ALTHOUGH MOST MODELS
ARE KEEPING THE BULK OF THE PRECIP SOUTH OF THE CWA WITH THE
EXCEPTION OF THE 12Z ECMWF.

MARINE...

STRONG SOUTHWESTERLY WIND FIELD IS NOW IN PLACE WITH WINDSPEEDS AREA
WIDE RANGING BETWEEN 25 AND 35 KNOTS. SMALL CRAFT ADVISORIES REMAIN
IN EFFECT FOR ALL NEARSHORE ZONES. BREEZY WESTERLY WINDS WILL
PERSIST THROUGH MIDWEEK AS CONDITIONS REMAIN RELATIVELY STATIC WITH
LOW PRESSURE PARKED OVER THE GREAT LAKES. ADDITIONAL SMALL CRAFT
ADVISORIES FOR WIND WILL LIKELY BE NEEDED ON TUESDAY AND POSSIBLY
ONCE MORE ON WEDNESDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT TUESDAY FOR LEZ444.

&&

$$

UPDATE.......SC
AVIATION.....SC
SHORT TERM...SF
LONG TERM....CB/SS
MARINE.......CB


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).




000
FXUS63 KAPX 210131
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
930 PM EDT MON APR 20 2015

.UPDATE...
ISSUED AT 930 PM EDT MON APR 20 2015

BAND OF WRAPAROUND PRECIP IS MAKING STEADY EASTWARD PROGRESS ACROSS
NORTHERN MI. THIS HAS BEEN MOSTLY LIQUID...BUT SHOULD BE TRENDING
MIXY IN WESTERN CHIP/MACK COUNTIES. WE HAVE ALSO STARTED TO MIX WITH
SNOW HERE AT OUR OFFICE. THIS IS SOMEWHAT AHEAD OF SCHEDULE...AND
HAVE BEEN UPDATING THE FORECAST TO SPEED UP THE ONSET OF MIXED
PRECIP.

STILL EXPECT TO SEE SOMETHING OF A BREAK OVERNIGHT...BEHIND THE
ONGOING PRECIP BAND AND AHEAD OF THE NEXT AREA OF PRECIP BACK IN THE
DULUTH MN AREA. DO NOT EXPECT PRECIP WILL TOTALLY CEASE OVERNIGHT...
GIVEN SHARPLY CYCLONIC/MOIST FLOW AND (IN AREAS) UPSLOPE FLOW. SO
CURRENT RELATIVELY WIDESPREAD PRECIP WILL GIVE WAY TO SCT/CHANCY
POPS OVERNIGHT.

&&

.SHORT TERM...(THROUGH TUESDAY)
ISSUED AT 354 PM EDT MON APR 20 2015

DRIER AIR HAS MOVED INTO THE NERN HALF OF THE CWA THIS AFTERNOON
BEHIND A 983MB SFC LOW JUST E OF LAKE SUPERIOR. LIGHT RAIN AND SNOW
SHOWERS ARE BEING OBSERVED OVER THE FANTASTIC UPPER
PENINSULA...WHILE RAIN SHOWER ARE OCCURRING FARTHER SOUTH AND EAST
OVER ERN WI AND WRN LOWER MI. THE WRAP AROUND PRECIP ON THE SW SIDE
OF THE SFC LOW WILL MOVE THROUGH THE CWA THIS EVENING BEFORE DRY AIR
SHIFTS THROUGH TONIGHT. EXPECT ALL RAIN THROUGH THIS EVENING.

AS COOLER WINDS ADVECTS INTO THE AREA FROM THE WSW BEHIND A COLD
FRONT CURRENTLY OVER ERN WI...LAKE ENHANCED/UPSLOPE/SHORTWAVE FORCED
RAIN AND SNOW ALSO BEING FORCED BY A SHORTWAVE WILL RESULT LATE
TONIGHT INTO TUE MORNING. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED
DUE TO WARM GROUND TEMPS AND 2M TEMPS ONLY FALLING INTO THE MID 30S.
SHOWERS WILL TURN TO ALL RAIN AS SFC TEMPS WARM LATE TUE MORNING
INTO TUE AFTERNOON. USED WET BULB ZERO HEIGHTS FROM THE NAM TO
DELINEATE RAIN/SNOW/MIX. HIGHS ON TUE WILL BE IN THE 40S.

&&

.LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 405 PM MON APR 20 2015

THE PATTERN THROUGH THE REST OF THE WEEK WILL BE DOMINATED BY A
MID/UPPER LEVEL LOW MOVING SLOWLY THROUGH THE NORTHERN GREAT LAKES
TOWARD SRN QUEBEC. THIS WILL BRING UNSETTLED WEATHER ALONG WITH
BELOW NORMAL TEMPERATURES.

TUE NIGHT...MODELS SUGGEST THAT A SHORTWAVE TROUGH SLIDING INTO THE
AREA WILL HELP ENHANCE THE PCPN. EXPECT THE HIGHS POPS/COVERAGE FOR
LOCATIONS FAVORED BY UPSLOPE WNW FLOW. WITH DEEP MOISTURE IN PLACE
OVER THE REGION AND 850 MB TEMPS DROPPING FROM AROUND -4C TO
-8C...THERE MAY ALSO BE ENOUGH INSTABILITY FOR SOME LAKE
ENHANCEMENT. WET-BULB ZERO HEIGHTS SUGGEST A TRANSITION FROM RAIN TO
SNOW WILL SPREAD THROUGH THE CWA FROM NW TO SE DURING THE EVENING.
SNOWFALL AMOUNTS TO AROUND AN INCH MAY BE POSSIBLE...MAINLY IN THE
HIGHER TERRAIN. WITH THE TEMPS FALLING OFF TO NEAR 30...SOME WET
SNOW/SLUSH MAY ALSO ACCUMULATE ON SOME ROADS.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN OVER OVER THE
SE CWA DURING PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE
CONTRIBUTION AS 850 MB TEMPS RANGE FROM -9C TO -12C...THE BEST
COVERAGE DURING THE DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM
LAKE SUPERIOR WHERE HEATING WILL BE STRONGEST WITH STEEP SFC-700 MB
LAPSE RATES 700 MB TEMPS TO AROUND -18C WED WILL ONLY MODERATE TO
NEAR -14C THU. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW NORMAL...IN
THE MID 30S TO AROUND 40.

FRI-MON...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH LOW(GFS/GEFS)OR NO(ECMWF) PCPN CHANCES.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 745 PM EDT MON APR 20 2015

MVFR TO IFR THIS EVENING...VFR OVERNIGHT...MVFR TUESDAY.

UNSEASONABLY STRONG LOW PRESSURE NORTH OF LAKE SUPERIOR WILL NOT BE
IN ANY HURRY TO DEPART...ONLY DRIFTING TOWARD JAMES BAY THRU TUESDAY
EVENING. PLENTY OF COOL AND MOIST AIR WILL CIRCULATE INTO THE REGION
BEHIND THE LOW. EXTENSIVE LOW CLOUD COVER IS EXPECTED...THOUGH FOR A
PORTION OF THE OVERNIGHT HOURS CIGS ARE EXPECTED TO RISE TO VFR.
OTHERWISE...MVFR TO IFR CIGS WILL BE SEEN...ALONG WITH PERIODS OF
LIGHT PRECIP (MOSTLY RAIN TONIGHT...RA/SN MIX TUESDAY).

SOMEWHAT BLUSTERY WESTERLY WINDS THRU THE FORECAST.

&&

.MARINE...

SW WINDS WILL CONTINUE AS THE SURFACE LOW BEGINS TO PULL NORTH OF
MICHIGAN...SHIFTING THE FOCUS OF THE STRONGEST WINDS AND BIGGEST
WAVES FROM THE LAKE HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

UPDATE...JZ
SHORT TERM...JIT
LONG TERM...JLB
AVIATION...JZ
MARINE...JIT



000
FXUS63 KAPX 210131
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
930 PM EDT MON APR 20 2015

.UPDATE...
ISSUED AT 930 PM EDT MON APR 20 2015

BAND OF WRAPAROUND PRECIP IS MAKING STEADY EASTWARD PROGRESS ACROSS
NORTHERN MI. THIS HAS BEEN MOSTLY LIQUID...BUT SHOULD BE TRENDING
MIXY IN WESTERN CHIP/MACK COUNTIES. WE HAVE ALSO STARTED TO MIX WITH
SNOW HERE AT OUR OFFICE. THIS IS SOMEWHAT AHEAD OF SCHEDULE...AND
HAVE BEEN UPDATING THE FORECAST TO SPEED UP THE ONSET OF MIXED
PRECIP.

STILL EXPECT TO SEE SOMETHING OF A BREAK OVERNIGHT...BEHIND THE
ONGOING PRECIP BAND AND AHEAD OF THE NEXT AREA OF PRECIP BACK IN THE
DULUTH MN AREA. DO NOT EXPECT PRECIP WILL TOTALLY CEASE OVERNIGHT...
GIVEN SHARPLY CYCLONIC/MOIST FLOW AND (IN AREAS) UPSLOPE FLOW. SO
CURRENT RELATIVELY WIDESPREAD PRECIP WILL GIVE WAY TO SCT/CHANCY
POPS OVERNIGHT.

&&

.SHORT TERM...(THROUGH TUESDAY)
ISSUED AT 354 PM EDT MON APR 20 2015

DRIER AIR HAS MOVED INTO THE NERN HALF OF THE CWA THIS AFTERNOON
BEHIND A 983MB SFC LOW JUST E OF LAKE SUPERIOR. LIGHT RAIN AND SNOW
SHOWERS ARE BEING OBSERVED OVER THE FANTASTIC UPPER
PENINSULA...WHILE RAIN SHOWER ARE OCCURRING FARTHER SOUTH AND EAST
OVER ERN WI AND WRN LOWER MI. THE WRAP AROUND PRECIP ON THE SW SIDE
OF THE SFC LOW WILL MOVE THROUGH THE CWA THIS EVENING BEFORE DRY AIR
SHIFTS THROUGH TONIGHT. EXPECT ALL RAIN THROUGH THIS EVENING.

AS COOLER WINDS ADVECTS INTO THE AREA FROM THE WSW BEHIND A COLD
FRONT CURRENTLY OVER ERN WI...LAKE ENHANCED/UPSLOPE/SHORTWAVE FORCED
RAIN AND SNOW ALSO BEING FORCED BY A SHORTWAVE WILL RESULT LATE
TONIGHT INTO TUE MORNING. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED
DUE TO WARM GROUND TEMPS AND 2M TEMPS ONLY FALLING INTO THE MID 30S.
SHOWERS WILL TURN TO ALL RAIN AS SFC TEMPS WARM LATE TUE MORNING
INTO TUE AFTERNOON. USED WET BULB ZERO HEIGHTS FROM THE NAM TO
DELINEATE RAIN/SNOW/MIX. HIGHS ON TUE WILL BE IN THE 40S.

&&

.LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 405 PM MON APR 20 2015

THE PATTERN THROUGH THE REST OF THE WEEK WILL BE DOMINATED BY A
MID/UPPER LEVEL LOW MOVING SLOWLY THROUGH THE NORTHERN GREAT LAKES
TOWARD SRN QUEBEC. THIS WILL BRING UNSETTLED WEATHER ALONG WITH
BELOW NORMAL TEMPERATURES.

TUE NIGHT...MODELS SUGGEST THAT A SHORTWAVE TROUGH SLIDING INTO THE
AREA WILL HELP ENHANCE THE PCPN. EXPECT THE HIGHS POPS/COVERAGE FOR
LOCATIONS FAVORED BY UPSLOPE WNW FLOW. WITH DEEP MOISTURE IN PLACE
OVER THE REGION AND 850 MB TEMPS DROPPING FROM AROUND -4C TO
-8C...THERE MAY ALSO BE ENOUGH INSTABILITY FOR SOME LAKE
ENHANCEMENT. WET-BULB ZERO HEIGHTS SUGGEST A TRANSITION FROM RAIN TO
SNOW WILL SPREAD THROUGH THE CWA FROM NW TO SE DURING THE EVENING.
SNOWFALL AMOUNTS TO AROUND AN INCH MAY BE POSSIBLE...MAINLY IN THE
HIGHER TERRAIN. WITH THE TEMPS FALLING OFF TO NEAR 30...SOME WET
SNOW/SLUSH MAY ALSO ACCUMULATE ON SOME ROADS.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN OVER OVER THE
SE CWA DURING PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE
CONTRIBUTION AS 850 MB TEMPS RANGE FROM -9C TO -12C...THE BEST
COVERAGE DURING THE DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM
LAKE SUPERIOR WHERE HEATING WILL BE STRONGEST WITH STEEP SFC-700 MB
LAPSE RATES 700 MB TEMPS TO AROUND -18C WED WILL ONLY MODERATE TO
NEAR -14C THU. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW NORMAL...IN
THE MID 30S TO AROUND 40.

FRI-MON...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH LOW(GFS/GEFS)OR NO(ECMWF) PCPN CHANCES.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 745 PM EDT MON APR 20 2015

MVFR TO IFR THIS EVENING...VFR OVERNIGHT...MVFR TUESDAY.

UNSEASONABLY STRONG LOW PRESSURE NORTH OF LAKE SUPERIOR WILL NOT BE
IN ANY HURRY TO DEPART...ONLY DRIFTING TOWARD JAMES BAY THRU TUESDAY
EVENING. PLENTY OF COOL AND MOIST AIR WILL CIRCULATE INTO THE REGION
BEHIND THE LOW. EXTENSIVE LOW CLOUD COVER IS EXPECTED...THOUGH FOR A
PORTION OF THE OVERNIGHT HOURS CIGS ARE EXPECTED TO RISE TO VFR.
OTHERWISE...MVFR TO IFR CIGS WILL BE SEEN...ALONG WITH PERIODS OF
LIGHT PRECIP (MOSTLY RAIN TONIGHT...RA/SN MIX TUESDAY).

SOMEWHAT BLUSTERY WESTERLY WINDS THRU THE FORECAST.

&&

.MARINE...

SW WINDS WILL CONTINUE AS THE SURFACE LOW BEGINS TO PULL NORTH OF
MICHIGAN...SHIFTING THE FOCUS OF THE STRONGEST WINDS AND BIGGEST
WAVES FROM THE LAKE HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

UPDATE...JZ
SHORT TERM...JIT
LONG TERM...JLB
AVIATION...JZ
MARINE...JIT



  [top]

000
FXUS63 KMQT 202347
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
747 PM EDT MON APR 20 2015

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 353 PM EDT MON APR 20 2015

12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEPENING UPR TROF
OVER CENTRAL NAMERICA BTWN RDGS ALONG THE E AND W COASTS...WITH 12HR
H5 HGT FALLS UP TO 150M NOTED OVER NRN WI IN ADVANCE OF SHRTWV
LIFTING NWD INTO THE UPR LKS TO THE E OF THE UPR TROF AXIS. IR AND
WV IMAGERY SHOW A WELL DEFINED COMMA HEAD CLD OVER THE UPR GREAT LKS
IN ADVANCE OF SHRTWV AND ON CYC SIDE OF ACCOMPANYING H7 LO TRACK.
STEADY RA UNDER THIS COMMA HEAD HAS MIXED WITH SN OVER THE WRN CWA
WHERE DYNAMIC COOLING AND SOME LLVL CAA HAVE COOLED THE COLUMN
SUFFICIENTLY. FARTHER TO THE E...DRY SLOTTING ON THE ACYC SIDE OF H7
LO TRACK HAS TENDED TO DIMINISH THE PCPN COVERAGE/INTENSITY OVER THE
FAR E. ANOTHER SHRTWV IS DIGGING SWD THRU FAR NW ONTARIO/MANITOBA ON
THE WRN FLANK OF H5 CLOSED LO

MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/PTYPE ASSOCIATED
WITH SHRTWV MOVING THRU THE UPR LKS RIGHT NOW AND THEN TNGT/TMRW
ACCOMPANYING PASSAGE OF NEXT SHRTWV AND WITHIN LINGERING DEEP CYC
FLOW UNDER CUTOFF H5 LO PROGGED TO LINGER OVER THE UPR LKS.

LATE TDAY/TNGT...AS SHRTWV E OF THE UPR TROF AXIS LIFTS TO THE N
THRU THIS AFTN AND TENDS TO SHEAR OUT...MODELS SHOW AREA OF SHARP
DEEP LYR QVECTOR CNVGC SUPPORTING AXIS OF COLDER CLD TOPS
DIMINISHING AND GIVING WAY TO SOME DEEP LYR QVECTOR DVGC. SO AREA OF
STEADY RA/SN OVER THE W SHOULD DIMINISH BY LATE AFTN WITH ARRIVAL OF
THE NEGATIVE DYNAMICS/MID LVL DRYING. POPS OVER THE E WL TEND TO
INCREASE LATE THIS AFTN/EARLY EVNG AS COMMA TAIL AXIS OF HIER RH
SWINGS E THRU THAT AREA...BUT PCPN INTENSITY WL NOT BE AS GREAT AS
OVER THE W SINCE THE SUPPORTING AXIS OF DIMINISHING DEEP LYR QVECTOR
CNVGC IS FCST TO REMAIN OVER THE W. NOT OUT OF THE QUESTION THERE
COULD BE A FEW INCHES OF WET SN ACCUM OVER THE HIER TERRAIN OF THE
W...BUT THERE SHOULD BE LTL IF ANY SN OVER THE E HALF WITH WEAKER
DYNAMIC FORCING/COOLING. LATER TNGT...THE TRAILING SHRTWV DIGGING
SWD TOWARD NW MN ON THE WRN FLANK OF CLOSED H5 LO IS FCST TO DIG TO
NEAR NW WI BY 12Z TUE...BRINGING SOME DPVA/MORE DEEP LYR QVECTOR
CNVGC TO THE W LATER TNGT. SHARP CYC UPSLOPE WNW FLOW IN THE
PRESENCE OF THE DEEPER FORCING/MSTR WL SUPPORT LIKELY POPS IN THIS
AREA. THERE COULD BE A FEW INCHES OF WET SN ACCUM OVER MAINLY THE
HIER TERRAIN. OVER THE CENTRAL AND E...THERE WL BE ONLY ISOLD-SCT RA
AND SN SHOWERS.

TUE...SHRTWV/ACCOMPANYING SFC LO PRES TROF ROTATING ARND CLOSED H5
LO SHIFTING SLOWLY TO THE E OVER LK SUP IS FCST TO WEAKEN SLOWLY...
LEADING TO SLOWLY DIMINISHING DEEP LYR QVECTOR CNVGC. ALTHOUGH THESE
TRENDS WL RESULT IN DIMINISHING POPS...DAYTIME HEATING/LLVL
DESTABILIZATION WL ENHANCE POPS ESPECIALLY OVER THE ERN CWA IN THE
AFTN...WHERE LLVL CNVGC WITHIN LO PRES TROF WL BE ENHANCED BY LK
BREEZE DEVELOPMENT. OTRW...LINGERING SHARP LLVL CNVGC AND THE
DAYTIME HEATING WL MAINTAIN AT LEAST CHC POPS. THE PCPN SHOULD BE
MAINLY SN IN THE MRNG...BUT THIS PCPN WL MIX WITH/CHG TO RA OVER THE
SE HALF IN THE AFTN WITH DAYTIME HEATING/TEMPS RISING AOA 40.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 PM EDT MON APR 20 2015

A LARGE UPPER LOW CENTERED OVER NORTHERN ONTARIO WILL BE
INFLUENCING THE GREAT LAKES REGION THROUGH THE FIRST HALF OF THE
LONG TERM PERIOD. THIS WILL LEAD TO BELOW NORMAL TEMPERATURES AND
PERIODS OF SNOW BEFORE GRADUALLY SHIFTING EAST INTO THE ATLANTIC BY
THE WEEKEND.

AS THAT UPPER LOW SPINS BETWEEN LAKE SUPERIOR AND JAMES BAY...IT
WILL ROTATE SEVERAL SHORTWAVES ACROSS THE UPPER GREAT LAKES REGION
TUESDAY NIGHT THROUGH THURSDAY. THESE WAVES WILL BRING PERIODS OF
SHOWERS TO THE AREA...WITH HELP FROM BOTH LAKE SUPERIOR (850MB
TEMPS FALLING TO -10C TO -12C ON WEDNESDAY MORNING) AND TERRAIN
ENHANCEMENT (PERSISTENT LOW LEVEL NORTHWESTERLY FLOW). WILL CONTINUE
TO FOCUS THE HIGHEST POPS (LIKELY VALUES) IN THOSE AREAS FAVORED BY
ALL THREE FEATURES (HIGHER TERRAIN OF THE WEST/NORTHWEST) AND ALSO
EAST DOWNWIND OF LAKE SUPERIOR...AND INCLUDE CHANCE/SLIGHTS FOR THE
REST OF THE CWA. WITH THE AMOUNT OF COLD AIR IN PLACE...EXPECT THE
PRECIPITATION TO FALL MAINLY AS SNOW. WITH LOW LEVEL TEMPERATURES
WARMING AWAY OVER THE SOUTHERN THIRD OF THE CWA...COULD SEE SOME
RAIN MIXING IN THERE...BUT OTHERWISE SNOW WILL BE THE NORM. COULD
SEE A COUPLE INCHES OF ACCUMULATION IN THE FAVORED LOCATIONS
TUESDAY NIGHT AND UP TO AN INCH WEDNESDAY AND AGAIN WEDNESDAY
NIGHT. WITH DRIER AIR STARTING TO MOVE INTO THE AREA ON
THURSDAY (ASSOCIATED WITH A SURFACE RIDGE MOVING INTO THE
NORTHERN PLAINS...SHOULD SEE THE COVERAGE OF THE SHOWERS
DIMINISHING THROUGH THE DAY THURSDAY AND CONTINUING TO WEAKENING
INTO FRIDAY. ALSO...DON/T EXPECT HIGHS TO RISE MUCH OUT OF THE
LOW-MID 30S ON WED/THURS OVER THE NORTH HALF OF THE CWA...WITH SOME
HIGHS AROUND 40 OVER THE SOUTH CENTRAL. WILL LIKELY BREAK THE
RECORD LOW HIGH TEMPERATURE HERE AT OUR OFFICE ON WEDNESDAY (36 SET
IN 1972).

EXTENDED RANGE MODELS DIFFER ON HOW QUICKLY THE UPPER LOW DEPARTS
THIS WEEKEND...BUT SHOULD STILL SEE ENOUGH INFLUENCE FROM THE
SURFACE RIDGE MOVING INTO THE NORTHERN PLAINS TO KEEP MOST OF THE
AREA DRY. WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR...EXPECT
TEMPERATURES TO REMAIN BELOW NORMAL BUT IN THE 40S TO AROUND 50. AS
THE UPPER LOW RETROGRADES BACK OVER QUEBEC EARLY NEXT WEEK...COULD
SEE THE UPPER GREAT LAKES REGION BEING AFFECTED BY THE WESTERN EDGE
OF THE ENERGY ROTATING AROUND THE UPPER LOW AND LIKELY KEEPING
BELOW NORMAL TEMPERATURES IN PLACE THROUGH THE END OF APRIL.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 747 PM EDT MON APR 20 2015

AREA OF DEEPER MOISTURE AND STEADIER SNOW CONTINUES TO LIFT NE
ACROSS UPPER MI/LAKE SUPERIOR. BEHIND THIS DEEPER MOISTURE/STEADIER
SNOW...EXPECT MVFR CONDITIONS WITH -SHSN AT TIMES TO PREVAIL AT KIWD
THIS EVENING. AT KCMX...IFR CONDITIONS SHOULD IMPROVE TO MVFR IN THE
NEXT HR OR TWO. AT KSAW...IT`S POSSIBLE MVFR CONDITIONS COULD
IMPROVE TO VFR AT TIMES THIS EVENING. APPROACH OF ANOTHER
DISTURBANCE/LOW PRES TROF LATER TONIGHT SHOULD RESULT IN
DETERIORATING CONDITIONS TO IFR AT KIWD/KCMX. DOWNSLOPE WIND W TO SW
WINDS AT KSAW WILL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO KIWD/KCMX MID TO LATE MORNING ON TUE. -SHSN
WILL CONTINUE AT ALL TERMINALS TUE...AND IT`S NOT OUT OF THE
QUESTION THAT IFR VIS COULD OCCUR AT TIMES...ESPECIALLY AT KIWD/KSAW
AS DAYTIME HEATING/INSTABILITY AIDS -SHSN INTENSITY. WINDS WILL
GENERALLY REMAIN GUSTY...PARTICULARLY AT KCMX WHERE GUSTS OF 25-30KT
SHOULD BE COMMON FOR MUCH OF THE FCST PERIOD.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 353 PM EDT MON APR 20 2015

SHARP PRES GRADIENT ON THE SW FLANK OF SLOW MOVING LO PRES IN
ONTARIO WILL CAUSE W TO NW WINDS UP TO 25-30 KTS INTO THU. ALTHOUGH
THERE COULD BE SOME GALE FORCE GUSTS AT TIMES...WIDESPREAD GALES ARE
NOT EXPECTED. THE CLOSER APPROACH OF HI PRES LATER IN THE WEEK WILL
RESULT IN NW WINDS DIMINISHING TO NO MORE THAN 20 KTS ON FRI AND
SAT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...KC




000
FXUS63 KMQT 202347
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
747 PM EDT MON APR 20 2015

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 353 PM EDT MON APR 20 2015

12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEPENING UPR TROF
OVER CENTRAL NAMERICA BTWN RDGS ALONG THE E AND W COASTS...WITH 12HR
H5 HGT FALLS UP TO 150M NOTED OVER NRN WI IN ADVANCE OF SHRTWV
LIFTING NWD INTO THE UPR LKS TO THE E OF THE UPR TROF AXIS. IR AND
WV IMAGERY SHOW A WELL DEFINED COMMA HEAD CLD OVER THE UPR GREAT LKS
IN ADVANCE OF SHRTWV AND ON CYC SIDE OF ACCOMPANYING H7 LO TRACK.
STEADY RA UNDER THIS COMMA HEAD HAS MIXED WITH SN OVER THE WRN CWA
WHERE DYNAMIC COOLING AND SOME LLVL CAA HAVE COOLED THE COLUMN
SUFFICIENTLY. FARTHER TO THE E...DRY SLOTTING ON THE ACYC SIDE OF H7
LO TRACK HAS TENDED TO DIMINISH THE PCPN COVERAGE/INTENSITY OVER THE
FAR E. ANOTHER SHRTWV IS DIGGING SWD THRU FAR NW ONTARIO/MANITOBA ON
THE WRN FLANK OF H5 CLOSED LO

MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/PTYPE ASSOCIATED
WITH SHRTWV MOVING THRU THE UPR LKS RIGHT NOW AND THEN TNGT/TMRW
ACCOMPANYING PASSAGE OF NEXT SHRTWV AND WITHIN LINGERING DEEP CYC
FLOW UNDER CUTOFF H5 LO PROGGED TO LINGER OVER THE UPR LKS.

LATE TDAY/TNGT...AS SHRTWV E OF THE UPR TROF AXIS LIFTS TO THE N
THRU THIS AFTN AND TENDS TO SHEAR OUT...MODELS SHOW AREA OF SHARP
DEEP LYR QVECTOR CNVGC SUPPORTING AXIS OF COLDER CLD TOPS
DIMINISHING AND GIVING WAY TO SOME DEEP LYR QVECTOR DVGC. SO AREA OF
STEADY RA/SN OVER THE W SHOULD DIMINISH BY LATE AFTN WITH ARRIVAL OF
THE NEGATIVE DYNAMICS/MID LVL DRYING. POPS OVER THE E WL TEND TO
INCREASE LATE THIS AFTN/EARLY EVNG AS COMMA TAIL AXIS OF HIER RH
SWINGS E THRU THAT AREA...BUT PCPN INTENSITY WL NOT BE AS GREAT AS
OVER THE W SINCE THE SUPPORTING AXIS OF DIMINISHING DEEP LYR QVECTOR
CNVGC IS FCST TO REMAIN OVER THE W. NOT OUT OF THE QUESTION THERE
COULD BE A FEW INCHES OF WET SN ACCUM OVER THE HIER TERRAIN OF THE
W...BUT THERE SHOULD BE LTL IF ANY SN OVER THE E HALF WITH WEAKER
DYNAMIC FORCING/COOLING. LATER TNGT...THE TRAILING SHRTWV DIGGING
SWD TOWARD NW MN ON THE WRN FLANK OF CLOSED H5 LO IS FCST TO DIG TO
NEAR NW WI BY 12Z TUE...BRINGING SOME DPVA/MORE DEEP LYR QVECTOR
CNVGC TO THE W LATER TNGT. SHARP CYC UPSLOPE WNW FLOW IN THE
PRESENCE OF THE DEEPER FORCING/MSTR WL SUPPORT LIKELY POPS IN THIS
AREA. THERE COULD BE A FEW INCHES OF WET SN ACCUM OVER MAINLY THE
HIER TERRAIN. OVER THE CENTRAL AND E...THERE WL BE ONLY ISOLD-SCT RA
AND SN SHOWERS.

TUE...SHRTWV/ACCOMPANYING SFC LO PRES TROF ROTATING ARND CLOSED H5
LO SHIFTING SLOWLY TO THE E OVER LK SUP IS FCST TO WEAKEN SLOWLY...
LEADING TO SLOWLY DIMINISHING DEEP LYR QVECTOR CNVGC. ALTHOUGH THESE
TRENDS WL RESULT IN DIMINISHING POPS...DAYTIME HEATING/LLVL
DESTABILIZATION WL ENHANCE POPS ESPECIALLY OVER THE ERN CWA IN THE
AFTN...WHERE LLVL CNVGC WITHIN LO PRES TROF WL BE ENHANCED BY LK
BREEZE DEVELOPMENT. OTRW...LINGERING SHARP LLVL CNVGC AND THE
DAYTIME HEATING WL MAINTAIN AT LEAST CHC POPS. THE PCPN SHOULD BE
MAINLY SN IN THE MRNG...BUT THIS PCPN WL MIX WITH/CHG TO RA OVER THE
SE HALF IN THE AFTN WITH DAYTIME HEATING/TEMPS RISING AOA 40.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 PM EDT MON APR 20 2015

A LARGE UPPER LOW CENTERED OVER NORTHERN ONTARIO WILL BE
INFLUENCING THE GREAT LAKES REGION THROUGH THE FIRST HALF OF THE
LONG TERM PERIOD. THIS WILL LEAD TO BELOW NORMAL TEMPERATURES AND
PERIODS OF SNOW BEFORE GRADUALLY SHIFTING EAST INTO THE ATLANTIC BY
THE WEEKEND.

AS THAT UPPER LOW SPINS BETWEEN LAKE SUPERIOR AND JAMES BAY...IT
WILL ROTATE SEVERAL SHORTWAVES ACROSS THE UPPER GREAT LAKES REGION
TUESDAY NIGHT THROUGH THURSDAY. THESE WAVES WILL BRING PERIODS OF
SHOWERS TO THE AREA...WITH HELP FROM BOTH LAKE SUPERIOR (850MB
TEMPS FALLING TO -10C TO -12C ON WEDNESDAY MORNING) AND TERRAIN
ENHANCEMENT (PERSISTENT LOW LEVEL NORTHWESTERLY FLOW). WILL CONTINUE
TO FOCUS THE HIGHEST POPS (LIKELY VALUES) IN THOSE AREAS FAVORED BY
ALL THREE FEATURES (HIGHER TERRAIN OF THE WEST/NORTHWEST) AND ALSO
EAST DOWNWIND OF LAKE SUPERIOR...AND INCLUDE CHANCE/SLIGHTS FOR THE
REST OF THE CWA. WITH THE AMOUNT OF COLD AIR IN PLACE...EXPECT THE
PRECIPITATION TO FALL MAINLY AS SNOW. WITH LOW LEVEL TEMPERATURES
WARMING AWAY OVER THE SOUTHERN THIRD OF THE CWA...COULD SEE SOME
RAIN MIXING IN THERE...BUT OTHERWISE SNOW WILL BE THE NORM. COULD
SEE A COUPLE INCHES OF ACCUMULATION IN THE FAVORED LOCATIONS
TUESDAY NIGHT AND UP TO AN INCH WEDNESDAY AND AGAIN WEDNESDAY
NIGHT. WITH DRIER AIR STARTING TO MOVE INTO THE AREA ON
THURSDAY (ASSOCIATED WITH A SURFACE RIDGE MOVING INTO THE
NORTHERN PLAINS...SHOULD SEE THE COVERAGE OF THE SHOWERS
DIMINISHING THROUGH THE DAY THURSDAY AND CONTINUING TO WEAKENING
INTO FRIDAY. ALSO...DON/T EXPECT HIGHS TO RISE MUCH OUT OF THE
LOW-MID 30S ON WED/THURS OVER THE NORTH HALF OF THE CWA...WITH SOME
HIGHS AROUND 40 OVER THE SOUTH CENTRAL. WILL LIKELY BREAK THE
RECORD LOW HIGH TEMPERATURE HERE AT OUR OFFICE ON WEDNESDAY (36 SET
IN 1972).

EXTENDED RANGE MODELS DIFFER ON HOW QUICKLY THE UPPER LOW DEPARTS
THIS WEEKEND...BUT SHOULD STILL SEE ENOUGH INFLUENCE FROM THE
SURFACE RIDGE MOVING INTO THE NORTHERN PLAINS TO KEEP MOST OF THE
AREA DRY. WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR...EXPECT
TEMPERATURES TO REMAIN BELOW NORMAL BUT IN THE 40S TO AROUND 50. AS
THE UPPER LOW RETROGRADES BACK OVER QUEBEC EARLY NEXT WEEK...COULD
SEE THE UPPER GREAT LAKES REGION BEING AFFECTED BY THE WESTERN EDGE
OF THE ENERGY ROTATING AROUND THE UPPER LOW AND LIKELY KEEPING
BELOW NORMAL TEMPERATURES IN PLACE THROUGH THE END OF APRIL.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 747 PM EDT MON APR 20 2015

AREA OF DEEPER MOISTURE AND STEADIER SNOW CONTINUES TO LIFT NE
ACROSS UPPER MI/LAKE SUPERIOR. BEHIND THIS DEEPER MOISTURE/STEADIER
SNOW...EXPECT MVFR CONDITIONS WITH -SHSN AT TIMES TO PREVAIL AT KIWD
THIS EVENING. AT KCMX...IFR CONDITIONS SHOULD IMPROVE TO MVFR IN THE
NEXT HR OR TWO. AT KSAW...IT`S POSSIBLE MVFR CONDITIONS COULD
IMPROVE TO VFR AT TIMES THIS EVENING. APPROACH OF ANOTHER
DISTURBANCE/LOW PRES TROF LATER TONIGHT SHOULD RESULT IN
DETERIORATING CONDITIONS TO IFR AT KIWD/KCMX. DOWNSLOPE WIND W TO SW
WINDS AT KSAW WILL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO KIWD/KCMX MID TO LATE MORNING ON TUE. -SHSN
WILL CONTINUE AT ALL TERMINALS TUE...AND IT`S NOT OUT OF THE
QUESTION THAT IFR VIS COULD OCCUR AT TIMES...ESPECIALLY AT KIWD/KSAW
AS DAYTIME HEATING/INSTABILITY AIDS -SHSN INTENSITY. WINDS WILL
GENERALLY REMAIN GUSTY...PARTICULARLY AT KCMX WHERE GUSTS OF 25-30KT
SHOULD BE COMMON FOR MUCH OF THE FCST PERIOD.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 353 PM EDT MON APR 20 2015

SHARP PRES GRADIENT ON THE SW FLANK OF SLOW MOVING LO PRES IN
ONTARIO WILL CAUSE W TO NW WINDS UP TO 25-30 KTS INTO THU. ALTHOUGH
THERE COULD BE SOME GALE FORCE GUSTS AT TIMES...WIDESPREAD GALES ARE
NOT EXPECTED. THE CLOSER APPROACH OF HI PRES LATER IN THE WEEK WILL
RESULT IN NW WINDS DIMINISHING TO NO MORE THAN 20 KTS ON FRI AND
SAT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...KC



000
FXUS63 KMQT 202347
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
747 PM EDT MON APR 20 2015

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 353 PM EDT MON APR 20 2015

12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEPENING UPR TROF
OVER CENTRAL NAMERICA BTWN RDGS ALONG THE E AND W COASTS...WITH 12HR
H5 HGT FALLS UP TO 150M NOTED OVER NRN WI IN ADVANCE OF SHRTWV
LIFTING NWD INTO THE UPR LKS TO THE E OF THE UPR TROF AXIS. IR AND
WV IMAGERY SHOW A WELL DEFINED COMMA HEAD CLD OVER THE UPR GREAT LKS
IN ADVANCE OF SHRTWV AND ON CYC SIDE OF ACCOMPANYING H7 LO TRACK.
STEADY RA UNDER THIS COMMA HEAD HAS MIXED WITH SN OVER THE WRN CWA
WHERE DYNAMIC COOLING AND SOME LLVL CAA HAVE COOLED THE COLUMN
SUFFICIENTLY. FARTHER TO THE E...DRY SLOTTING ON THE ACYC SIDE OF H7
LO TRACK HAS TENDED TO DIMINISH THE PCPN COVERAGE/INTENSITY OVER THE
FAR E. ANOTHER SHRTWV IS DIGGING SWD THRU FAR NW ONTARIO/MANITOBA ON
THE WRN FLANK OF H5 CLOSED LO

MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/PTYPE ASSOCIATED
WITH SHRTWV MOVING THRU THE UPR LKS RIGHT NOW AND THEN TNGT/TMRW
ACCOMPANYING PASSAGE OF NEXT SHRTWV AND WITHIN LINGERING DEEP CYC
FLOW UNDER CUTOFF H5 LO PROGGED TO LINGER OVER THE UPR LKS.

LATE TDAY/TNGT...AS SHRTWV E OF THE UPR TROF AXIS LIFTS TO THE N
THRU THIS AFTN AND TENDS TO SHEAR OUT...MODELS SHOW AREA OF SHARP
DEEP LYR QVECTOR CNVGC SUPPORTING AXIS OF COLDER CLD TOPS
DIMINISHING AND GIVING WAY TO SOME DEEP LYR QVECTOR DVGC. SO AREA OF
STEADY RA/SN OVER THE W SHOULD DIMINISH BY LATE AFTN WITH ARRIVAL OF
THE NEGATIVE DYNAMICS/MID LVL DRYING. POPS OVER THE E WL TEND TO
INCREASE LATE THIS AFTN/EARLY EVNG AS COMMA TAIL AXIS OF HIER RH
SWINGS E THRU THAT AREA...BUT PCPN INTENSITY WL NOT BE AS GREAT AS
OVER THE W SINCE THE SUPPORTING AXIS OF DIMINISHING DEEP LYR QVECTOR
CNVGC IS FCST TO REMAIN OVER THE W. NOT OUT OF THE QUESTION THERE
COULD BE A FEW INCHES OF WET SN ACCUM OVER THE HIER TERRAIN OF THE
W...BUT THERE SHOULD BE LTL IF ANY SN OVER THE E HALF WITH WEAKER
DYNAMIC FORCING/COOLING. LATER TNGT...THE TRAILING SHRTWV DIGGING
SWD TOWARD NW MN ON THE WRN FLANK OF CLOSED H5 LO IS FCST TO DIG TO
NEAR NW WI BY 12Z TUE...BRINGING SOME DPVA/MORE DEEP LYR QVECTOR
CNVGC TO THE W LATER TNGT. SHARP CYC UPSLOPE WNW FLOW IN THE
PRESENCE OF THE DEEPER FORCING/MSTR WL SUPPORT LIKELY POPS IN THIS
AREA. THERE COULD BE A FEW INCHES OF WET SN ACCUM OVER MAINLY THE
HIER TERRAIN. OVER THE CENTRAL AND E...THERE WL BE ONLY ISOLD-SCT RA
AND SN SHOWERS.

TUE...SHRTWV/ACCOMPANYING SFC LO PRES TROF ROTATING ARND CLOSED H5
LO SHIFTING SLOWLY TO THE E OVER LK SUP IS FCST TO WEAKEN SLOWLY...
LEADING TO SLOWLY DIMINISHING DEEP LYR QVECTOR CNVGC. ALTHOUGH THESE
TRENDS WL RESULT IN DIMINISHING POPS...DAYTIME HEATING/LLVL
DESTABILIZATION WL ENHANCE POPS ESPECIALLY OVER THE ERN CWA IN THE
AFTN...WHERE LLVL CNVGC WITHIN LO PRES TROF WL BE ENHANCED BY LK
BREEZE DEVELOPMENT. OTRW...LINGERING SHARP LLVL CNVGC AND THE
DAYTIME HEATING WL MAINTAIN AT LEAST CHC POPS. THE PCPN SHOULD BE
MAINLY SN IN THE MRNG...BUT THIS PCPN WL MIX WITH/CHG TO RA OVER THE
SE HALF IN THE AFTN WITH DAYTIME HEATING/TEMPS RISING AOA 40.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 PM EDT MON APR 20 2015

A LARGE UPPER LOW CENTERED OVER NORTHERN ONTARIO WILL BE
INFLUENCING THE GREAT LAKES REGION THROUGH THE FIRST HALF OF THE
LONG TERM PERIOD. THIS WILL LEAD TO BELOW NORMAL TEMPERATURES AND
PERIODS OF SNOW BEFORE GRADUALLY SHIFTING EAST INTO THE ATLANTIC BY
THE WEEKEND.

AS THAT UPPER LOW SPINS BETWEEN LAKE SUPERIOR AND JAMES BAY...IT
WILL ROTATE SEVERAL SHORTWAVES ACROSS THE UPPER GREAT LAKES REGION
TUESDAY NIGHT THROUGH THURSDAY. THESE WAVES WILL BRING PERIODS OF
SHOWERS TO THE AREA...WITH HELP FROM BOTH LAKE SUPERIOR (850MB
TEMPS FALLING TO -10C TO -12C ON WEDNESDAY MORNING) AND TERRAIN
ENHANCEMENT (PERSISTENT LOW LEVEL NORTHWESTERLY FLOW). WILL CONTINUE
TO FOCUS THE HIGHEST POPS (LIKELY VALUES) IN THOSE AREAS FAVORED BY
ALL THREE FEATURES (HIGHER TERRAIN OF THE WEST/NORTHWEST) AND ALSO
EAST DOWNWIND OF LAKE SUPERIOR...AND INCLUDE CHANCE/SLIGHTS FOR THE
REST OF THE CWA. WITH THE AMOUNT OF COLD AIR IN PLACE...EXPECT THE
PRECIPITATION TO FALL MAINLY AS SNOW. WITH LOW LEVEL TEMPERATURES
WARMING AWAY OVER THE SOUTHERN THIRD OF THE CWA...COULD SEE SOME
RAIN MIXING IN THERE...BUT OTHERWISE SNOW WILL BE THE NORM. COULD
SEE A COUPLE INCHES OF ACCUMULATION IN THE FAVORED LOCATIONS
TUESDAY NIGHT AND UP TO AN INCH WEDNESDAY AND AGAIN WEDNESDAY
NIGHT. WITH DRIER AIR STARTING TO MOVE INTO THE AREA ON
THURSDAY (ASSOCIATED WITH A SURFACE RIDGE MOVING INTO THE
NORTHERN PLAINS...SHOULD SEE THE COVERAGE OF THE SHOWERS
DIMINISHING THROUGH THE DAY THURSDAY AND CONTINUING TO WEAKENING
INTO FRIDAY. ALSO...DON/T EXPECT HIGHS TO RISE MUCH OUT OF THE
LOW-MID 30S ON WED/THURS OVER THE NORTH HALF OF THE CWA...WITH SOME
HIGHS AROUND 40 OVER THE SOUTH CENTRAL. WILL LIKELY BREAK THE
RECORD LOW HIGH TEMPERATURE HERE AT OUR OFFICE ON WEDNESDAY (36 SET
IN 1972).

EXTENDED RANGE MODELS DIFFER ON HOW QUICKLY THE UPPER LOW DEPARTS
THIS WEEKEND...BUT SHOULD STILL SEE ENOUGH INFLUENCE FROM THE
SURFACE RIDGE MOVING INTO THE NORTHERN PLAINS TO KEEP MOST OF THE
AREA DRY. WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR...EXPECT
TEMPERATURES TO REMAIN BELOW NORMAL BUT IN THE 40S TO AROUND 50. AS
THE UPPER LOW RETROGRADES BACK OVER QUEBEC EARLY NEXT WEEK...COULD
SEE THE UPPER GREAT LAKES REGION BEING AFFECTED BY THE WESTERN EDGE
OF THE ENERGY ROTATING AROUND THE UPPER LOW AND LIKELY KEEPING
BELOW NORMAL TEMPERATURES IN PLACE THROUGH THE END OF APRIL.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 747 PM EDT MON APR 20 2015

AREA OF DEEPER MOISTURE AND STEADIER SNOW CONTINUES TO LIFT NE
ACROSS UPPER MI/LAKE SUPERIOR. BEHIND THIS DEEPER MOISTURE/STEADIER
SNOW...EXPECT MVFR CONDITIONS WITH -SHSN AT TIMES TO PREVAIL AT KIWD
THIS EVENING. AT KCMX...IFR CONDITIONS SHOULD IMPROVE TO MVFR IN THE
NEXT HR OR TWO. AT KSAW...IT`S POSSIBLE MVFR CONDITIONS COULD
IMPROVE TO VFR AT TIMES THIS EVENING. APPROACH OF ANOTHER
DISTURBANCE/LOW PRES TROF LATER TONIGHT SHOULD RESULT IN
DETERIORATING CONDITIONS TO IFR AT KIWD/KCMX. DOWNSLOPE WIND W TO SW
WINDS AT KSAW WILL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO KIWD/KCMX MID TO LATE MORNING ON TUE. -SHSN
WILL CONTINUE AT ALL TERMINALS TUE...AND IT`S NOT OUT OF THE
QUESTION THAT IFR VIS COULD OCCUR AT TIMES...ESPECIALLY AT KIWD/KSAW
AS DAYTIME HEATING/INSTABILITY AIDS -SHSN INTENSITY. WINDS WILL
GENERALLY REMAIN GUSTY...PARTICULARLY AT KCMX WHERE GUSTS OF 25-30KT
SHOULD BE COMMON FOR MUCH OF THE FCST PERIOD.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 353 PM EDT MON APR 20 2015

SHARP PRES GRADIENT ON THE SW FLANK OF SLOW MOVING LO PRES IN
ONTARIO WILL CAUSE W TO NW WINDS UP TO 25-30 KTS INTO THU. ALTHOUGH
THERE COULD BE SOME GALE FORCE GUSTS AT TIMES...WIDESPREAD GALES ARE
NOT EXPECTED. THE CLOSER APPROACH OF HI PRES LATER IN THE WEEK WILL
RESULT IN NW WINDS DIMINISHING TO NO MORE THAN 20 KTS ON FRI AND
SAT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...KC




000
FXUS63 KMQT 202347
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
747 PM EDT MON APR 20 2015

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 353 PM EDT MON APR 20 2015

12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEPENING UPR TROF
OVER CENTRAL NAMERICA BTWN RDGS ALONG THE E AND W COASTS...WITH 12HR
H5 HGT FALLS UP TO 150M NOTED OVER NRN WI IN ADVANCE OF SHRTWV
LIFTING NWD INTO THE UPR LKS TO THE E OF THE UPR TROF AXIS. IR AND
WV IMAGERY SHOW A WELL DEFINED COMMA HEAD CLD OVER THE UPR GREAT LKS
IN ADVANCE OF SHRTWV AND ON CYC SIDE OF ACCOMPANYING H7 LO TRACK.
STEADY RA UNDER THIS COMMA HEAD HAS MIXED WITH SN OVER THE WRN CWA
WHERE DYNAMIC COOLING AND SOME LLVL CAA HAVE COOLED THE COLUMN
SUFFICIENTLY. FARTHER TO THE E...DRY SLOTTING ON THE ACYC SIDE OF H7
LO TRACK HAS TENDED TO DIMINISH THE PCPN COVERAGE/INTENSITY OVER THE
FAR E. ANOTHER SHRTWV IS DIGGING SWD THRU FAR NW ONTARIO/MANITOBA ON
THE WRN FLANK OF H5 CLOSED LO

MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/PTYPE ASSOCIATED
WITH SHRTWV MOVING THRU THE UPR LKS RIGHT NOW AND THEN TNGT/TMRW
ACCOMPANYING PASSAGE OF NEXT SHRTWV AND WITHIN LINGERING DEEP CYC
FLOW UNDER CUTOFF H5 LO PROGGED TO LINGER OVER THE UPR LKS.

LATE TDAY/TNGT...AS SHRTWV E OF THE UPR TROF AXIS LIFTS TO THE N
THRU THIS AFTN AND TENDS TO SHEAR OUT...MODELS SHOW AREA OF SHARP
DEEP LYR QVECTOR CNVGC SUPPORTING AXIS OF COLDER CLD TOPS
DIMINISHING AND GIVING WAY TO SOME DEEP LYR QVECTOR DVGC. SO AREA OF
STEADY RA/SN OVER THE W SHOULD DIMINISH BY LATE AFTN WITH ARRIVAL OF
THE NEGATIVE DYNAMICS/MID LVL DRYING. POPS OVER THE E WL TEND TO
INCREASE LATE THIS AFTN/EARLY EVNG AS COMMA TAIL AXIS OF HIER RH
SWINGS E THRU THAT AREA...BUT PCPN INTENSITY WL NOT BE AS GREAT AS
OVER THE W SINCE THE SUPPORTING AXIS OF DIMINISHING DEEP LYR QVECTOR
CNVGC IS FCST TO REMAIN OVER THE W. NOT OUT OF THE QUESTION THERE
COULD BE A FEW INCHES OF WET SN ACCUM OVER THE HIER TERRAIN OF THE
W...BUT THERE SHOULD BE LTL IF ANY SN OVER THE E HALF WITH WEAKER
DYNAMIC FORCING/COOLING. LATER TNGT...THE TRAILING SHRTWV DIGGING
SWD TOWARD NW MN ON THE WRN FLANK OF CLOSED H5 LO IS FCST TO DIG TO
NEAR NW WI BY 12Z TUE...BRINGING SOME DPVA/MORE DEEP LYR QVECTOR
CNVGC TO THE W LATER TNGT. SHARP CYC UPSLOPE WNW FLOW IN THE
PRESENCE OF THE DEEPER FORCING/MSTR WL SUPPORT LIKELY POPS IN THIS
AREA. THERE COULD BE A FEW INCHES OF WET SN ACCUM OVER MAINLY THE
HIER TERRAIN. OVER THE CENTRAL AND E...THERE WL BE ONLY ISOLD-SCT RA
AND SN SHOWERS.

TUE...SHRTWV/ACCOMPANYING SFC LO PRES TROF ROTATING ARND CLOSED H5
LO SHIFTING SLOWLY TO THE E OVER LK SUP IS FCST TO WEAKEN SLOWLY...
LEADING TO SLOWLY DIMINISHING DEEP LYR QVECTOR CNVGC. ALTHOUGH THESE
TRENDS WL RESULT IN DIMINISHING POPS...DAYTIME HEATING/LLVL
DESTABILIZATION WL ENHANCE POPS ESPECIALLY OVER THE ERN CWA IN THE
AFTN...WHERE LLVL CNVGC WITHIN LO PRES TROF WL BE ENHANCED BY LK
BREEZE DEVELOPMENT. OTRW...LINGERING SHARP LLVL CNVGC AND THE
DAYTIME HEATING WL MAINTAIN AT LEAST CHC POPS. THE PCPN SHOULD BE
MAINLY SN IN THE MRNG...BUT THIS PCPN WL MIX WITH/CHG TO RA OVER THE
SE HALF IN THE AFTN WITH DAYTIME HEATING/TEMPS RISING AOA 40.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 PM EDT MON APR 20 2015

A LARGE UPPER LOW CENTERED OVER NORTHERN ONTARIO WILL BE
INFLUENCING THE GREAT LAKES REGION THROUGH THE FIRST HALF OF THE
LONG TERM PERIOD. THIS WILL LEAD TO BELOW NORMAL TEMPERATURES AND
PERIODS OF SNOW BEFORE GRADUALLY SHIFTING EAST INTO THE ATLANTIC BY
THE WEEKEND.

AS THAT UPPER LOW SPINS BETWEEN LAKE SUPERIOR AND JAMES BAY...IT
WILL ROTATE SEVERAL SHORTWAVES ACROSS THE UPPER GREAT LAKES REGION
TUESDAY NIGHT THROUGH THURSDAY. THESE WAVES WILL BRING PERIODS OF
SHOWERS TO THE AREA...WITH HELP FROM BOTH LAKE SUPERIOR (850MB
TEMPS FALLING TO -10C TO -12C ON WEDNESDAY MORNING) AND TERRAIN
ENHANCEMENT (PERSISTENT LOW LEVEL NORTHWESTERLY FLOW). WILL CONTINUE
TO FOCUS THE HIGHEST POPS (LIKELY VALUES) IN THOSE AREAS FAVORED BY
ALL THREE FEATURES (HIGHER TERRAIN OF THE WEST/NORTHWEST) AND ALSO
EAST DOWNWIND OF LAKE SUPERIOR...AND INCLUDE CHANCE/SLIGHTS FOR THE
REST OF THE CWA. WITH THE AMOUNT OF COLD AIR IN PLACE...EXPECT THE
PRECIPITATION TO FALL MAINLY AS SNOW. WITH LOW LEVEL TEMPERATURES
WARMING AWAY OVER THE SOUTHERN THIRD OF THE CWA...COULD SEE SOME
RAIN MIXING IN THERE...BUT OTHERWISE SNOW WILL BE THE NORM. COULD
SEE A COUPLE INCHES OF ACCUMULATION IN THE FAVORED LOCATIONS
TUESDAY NIGHT AND UP TO AN INCH WEDNESDAY AND AGAIN WEDNESDAY
NIGHT. WITH DRIER AIR STARTING TO MOVE INTO THE AREA ON
THURSDAY (ASSOCIATED WITH A SURFACE RIDGE MOVING INTO THE
NORTHERN PLAINS...SHOULD SEE THE COVERAGE OF THE SHOWERS
DIMINISHING THROUGH THE DAY THURSDAY AND CONTINUING TO WEAKENING
INTO FRIDAY. ALSO...DON/T EXPECT HIGHS TO RISE MUCH OUT OF THE
LOW-MID 30S ON WED/THURS OVER THE NORTH HALF OF THE CWA...WITH SOME
HIGHS AROUND 40 OVER THE SOUTH CENTRAL. WILL LIKELY BREAK THE
RECORD LOW HIGH TEMPERATURE HERE AT OUR OFFICE ON WEDNESDAY (36 SET
IN 1972).

EXTENDED RANGE MODELS DIFFER ON HOW QUICKLY THE UPPER LOW DEPARTS
THIS WEEKEND...BUT SHOULD STILL SEE ENOUGH INFLUENCE FROM THE
SURFACE RIDGE MOVING INTO THE NORTHERN PLAINS TO KEEP MOST OF THE
AREA DRY. WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR...EXPECT
TEMPERATURES TO REMAIN BELOW NORMAL BUT IN THE 40S TO AROUND 50. AS
THE UPPER LOW RETROGRADES BACK OVER QUEBEC EARLY NEXT WEEK...COULD
SEE THE UPPER GREAT LAKES REGION BEING AFFECTED BY THE WESTERN EDGE
OF THE ENERGY ROTATING AROUND THE UPPER LOW AND LIKELY KEEPING
BELOW NORMAL TEMPERATURES IN PLACE THROUGH THE END OF APRIL.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 747 PM EDT MON APR 20 2015

AREA OF DEEPER MOISTURE AND STEADIER SNOW CONTINUES TO LIFT NE
ACROSS UPPER MI/LAKE SUPERIOR. BEHIND THIS DEEPER MOISTURE/STEADIER
SNOW...EXPECT MVFR CONDITIONS WITH -SHSN AT TIMES TO PREVAIL AT KIWD
THIS EVENING. AT KCMX...IFR CONDITIONS SHOULD IMPROVE TO MVFR IN THE
NEXT HR OR TWO. AT KSAW...IT`S POSSIBLE MVFR CONDITIONS COULD
IMPROVE TO VFR AT TIMES THIS EVENING. APPROACH OF ANOTHER
DISTURBANCE/LOW PRES TROF LATER TONIGHT SHOULD RESULT IN
DETERIORATING CONDITIONS TO IFR AT KIWD/KCMX. DOWNSLOPE WIND W TO SW
WINDS AT KSAW WILL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO KIWD/KCMX MID TO LATE MORNING ON TUE. -SHSN
WILL CONTINUE AT ALL TERMINALS TUE...AND IT`S NOT OUT OF THE
QUESTION THAT IFR VIS COULD OCCUR AT TIMES...ESPECIALLY AT KIWD/KSAW
AS DAYTIME HEATING/INSTABILITY AIDS -SHSN INTENSITY. WINDS WILL
GENERALLY REMAIN GUSTY...PARTICULARLY AT KCMX WHERE GUSTS OF 25-30KT
SHOULD BE COMMON FOR MUCH OF THE FCST PERIOD.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 353 PM EDT MON APR 20 2015

SHARP PRES GRADIENT ON THE SW FLANK OF SLOW MOVING LO PRES IN
ONTARIO WILL CAUSE W TO NW WINDS UP TO 25-30 KTS INTO THU. ALTHOUGH
THERE COULD BE SOME GALE FORCE GUSTS AT TIMES...WIDESPREAD GALES ARE
NOT EXPECTED. THE CLOSER APPROACH OF HI PRES LATER IN THE WEEK WILL
RESULT IN NW WINDS DIMINISHING TO NO MORE THAN 20 KTS ON FRI AND
SAT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...KC



000
FXUS63 KAPX 202345
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
745 PM EDT MON APR 20 2015

.SHORT TERM...(THROUGH TUESDAY)
ISSUED AT 354 PM EDT MON APR 20 2015

DRIER AIR HAS MOVED INTO THE NERN HALF OF THE CWA THIS AFTERNOON
BEHIND A 983MB SFC LOW JUST E OF LAKE SUPERIOR. LIGHT RAIN AND SNOW
SHOWERS ARE BEING OBSERVED OVER THE FANTASTIC UPPER
PENINSULA...WHILE RAIN SHOWER ARE OCCURRING FARTHER SOUTH AND EAST
OVER ERN WI AND WRN LOWER MI. THE WRAP AROUND PRECIP ON THE SW SIDE
OF THE SFC LOW WILL MOVE THROUGH THE CWA THIS EVENING BEFORE DRY AIR
SHIFTS THROUGH TONIGHT. EXPECT ALL RAIN THROUGH THIS EVENING.

AS COOLER WINDS ADVECTS INTO THE AREA FROM THE WSW BEHIND A COLD
FRONT CURRENTLY OVER ERN WI...LAKE ENHANCED/UPSLOPE/SHORTWAVE FORCED
RAIN AND SNOW ALSO BEING FORCED BY A SHORTWAVE WILL RESULT LATE
TONIGHT INTO TUE MORNING. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED
DUE TO WARM GROUND TEMPS AND 2M TEMPS ONLY FALLING INTO THE MID 30S.
SHOWERS WILL TURN TO ALL RAIN AS SFC TEMPS WARM LATE TUE MORNING
INTO TUE AFTERNOON. USED WET BULB ZERO HEIGHTS FROM THE NAM TO
DELINEATE RAIN/SNOW/MIX. HIGHS ON TUE WILL BE IN THE 40S.

&&

.LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 405 PM MON APR 20 2015

THE PATTERN THROUGH THE REST OF THE WEEK WILL BE DOMINATED BY A
MID/UPPER LEVEL LOW MOVING SLOWLY THROUGH THE NORTHERN GREAT LAKES
TOWARD SRN QUEBEC. THIS WILL BRING UNSETTLED WEATHER ALONG WITH
BELOW NORMAL TEMPERATURES.

TUE NIGHT...MODELS SUGGEST THAT A SHORTWAVE TROUGH SLIDING INTO THE
AREA WILL HELP ENHANCE THE PCPN. EXPECT THE HIGHS POPS/COVERAGE FOR
LOCATIONS FAVORED BY UPSLOPE WNW FLOW. WITH DEEP MOISTURE IN PLACE
OVER THE REGION AND 850 MB TEMPS DROPPING FROM AROUND -4C TO
-8C...THERE MAY ALSO BE ENOUGH INSTABILITY FOR SOME LAKE
ENHANCEMENT. WET-BULB ZERO HEIGHTS SUGGEST A TRANSITION FROM RAIN TO
SNOW WILL SPREAD THROUGH THE CWA FROM NW TO SE DURING THE EVENING.
SNOWFALL AMOUNTS TO AROUND AN INCH MAY BE POSSIBLE...MAINLY IN THE
HIGHER TERRAIN. WITH THE TEMPS FALLING OFF TO NEAR 30...SOME WET
SNOW/SLUSH MAY ALSO ACCUMULATE ON SOME ROADS.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN OVER OVER THE
SE CWA DURING PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE
CONTRIBUTION AS 850 MB TEMPS RANGE FROM -9C TO -12C...THE BEST
COVERAGE DURING THE DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM
LAKE SUPERIOR WHERE HEATING WILL BE STRONGEST WITH STEEP SFC-700 MB
LAPSE RATES 700 MB TEMPS TO AROUND -18C WED WILL ONLY MODERATE TO
NEAR -14C THU. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW NORMAL...IN
THE MID 30S TO AROUND 40.

FRI-MON...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH LOW(GFS/GEFS)OR NO(ECMWF) PCPN CHANCES.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 745 PM EDT MON APR 20 2015

MVFR TO IFR THIS EVENING...VFR OVERNIGHT...MVFR TUESDAY.

UNSEASONABLY STRONG LOW PRESSURE NORTH OF LAKE SUPERIOR WILL NOT BE
IN ANY HURRY TO DEPART...ONLY DRIFTING TOWARD JAMES BAY THRU TUESDAY
EVENING. PLENTY OF COOL AND MOIST AIR WILL CIRCULATE INTO THE REGION
BEHIND THE LOW. EXTENSIVE LOW CLOUD COVER IS EXPECTED...THOUGH FOR A
PORTION OF THE OVERNIGHT HOURS CIGS ARE EXPECTED TO RISE TO VFR.
OTHERWISE...MVFR TO IFR CIGS WILL BE SEEN...ALONG WITH PERIODS OF
LIGHT PRECIP (MOSTLY RAIN TONIGHT...RA/SN MIX TUESDAY).

SOMEWHAT BLUSTERY WESTERLY WINDS THRU THE FORECAST.

&&

.MARINE...

SW WINDS WILL CONTINUE AS THE SURFACE LOW BEGINS TO PULL NORTH OF
MICHIGAN...SHIFTING THE FOCUS OF THE STRONGEST WINDS AND BIGGEST
WAVES FROM THE LAKE HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...JIT
LONG TERM...JLB
AVIATION...JIT
MARINE...JIT



000
FXUS63 KAPX 202345
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
745 PM EDT MON APR 20 2015

.SHORT TERM...(THROUGH TUESDAY)
ISSUED AT 354 PM EDT MON APR 20 2015

DRIER AIR HAS MOVED INTO THE NERN HALF OF THE CWA THIS AFTERNOON
BEHIND A 983MB SFC LOW JUST E OF LAKE SUPERIOR. LIGHT RAIN AND SNOW
SHOWERS ARE BEING OBSERVED OVER THE FANTASTIC UPPER
PENINSULA...WHILE RAIN SHOWER ARE OCCURRING FARTHER SOUTH AND EAST
OVER ERN WI AND WRN LOWER MI. THE WRAP AROUND PRECIP ON THE SW SIDE
OF THE SFC LOW WILL MOVE THROUGH THE CWA THIS EVENING BEFORE DRY AIR
SHIFTS THROUGH TONIGHT. EXPECT ALL RAIN THROUGH THIS EVENING.

AS COOLER WINDS ADVECTS INTO THE AREA FROM THE WSW BEHIND A COLD
FRONT CURRENTLY OVER ERN WI...LAKE ENHANCED/UPSLOPE/SHORTWAVE FORCED
RAIN AND SNOW ALSO BEING FORCED BY A SHORTWAVE WILL RESULT LATE
TONIGHT INTO TUE MORNING. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED
DUE TO WARM GROUND TEMPS AND 2M TEMPS ONLY FALLING INTO THE MID 30S.
SHOWERS WILL TURN TO ALL RAIN AS SFC TEMPS WARM LATE TUE MORNING
INTO TUE AFTERNOON. USED WET BULB ZERO HEIGHTS FROM THE NAM TO
DELINEATE RAIN/SNOW/MIX. HIGHS ON TUE WILL BE IN THE 40S.

&&

.LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 405 PM MON APR 20 2015

THE PATTERN THROUGH THE REST OF THE WEEK WILL BE DOMINATED BY A
MID/UPPER LEVEL LOW MOVING SLOWLY THROUGH THE NORTHERN GREAT LAKES
TOWARD SRN QUEBEC. THIS WILL BRING UNSETTLED WEATHER ALONG WITH
BELOW NORMAL TEMPERATURES.

TUE NIGHT...MODELS SUGGEST THAT A SHORTWAVE TROUGH SLIDING INTO THE
AREA WILL HELP ENHANCE THE PCPN. EXPECT THE HIGHS POPS/COVERAGE FOR
LOCATIONS FAVORED BY UPSLOPE WNW FLOW. WITH DEEP MOISTURE IN PLACE
OVER THE REGION AND 850 MB TEMPS DROPPING FROM AROUND -4C TO
-8C...THERE MAY ALSO BE ENOUGH INSTABILITY FOR SOME LAKE
ENHANCEMENT. WET-BULB ZERO HEIGHTS SUGGEST A TRANSITION FROM RAIN TO
SNOW WILL SPREAD THROUGH THE CWA FROM NW TO SE DURING THE EVENING.
SNOWFALL AMOUNTS TO AROUND AN INCH MAY BE POSSIBLE...MAINLY IN THE
HIGHER TERRAIN. WITH THE TEMPS FALLING OFF TO NEAR 30...SOME WET
SNOW/SLUSH MAY ALSO ACCUMULATE ON SOME ROADS.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN OVER OVER THE
SE CWA DURING PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE
CONTRIBUTION AS 850 MB TEMPS RANGE FROM -9C TO -12C...THE BEST
COVERAGE DURING THE DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM
LAKE SUPERIOR WHERE HEATING WILL BE STRONGEST WITH STEEP SFC-700 MB
LAPSE RATES 700 MB TEMPS TO AROUND -18C WED WILL ONLY MODERATE TO
NEAR -14C THU. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW NORMAL...IN
THE MID 30S TO AROUND 40.

FRI-MON...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH LOW(GFS/GEFS)OR NO(ECMWF) PCPN CHANCES.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 745 PM EDT MON APR 20 2015

MVFR TO IFR THIS EVENING...VFR OVERNIGHT...MVFR TUESDAY.

UNSEASONABLY STRONG LOW PRESSURE NORTH OF LAKE SUPERIOR WILL NOT BE
IN ANY HURRY TO DEPART...ONLY DRIFTING TOWARD JAMES BAY THRU TUESDAY
EVENING. PLENTY OF COOL AND MOIST AIR WILL CIRCULATE INTO THE REGION
BEHIND THE LOW. EXTENSIVE LOW CLOUD COVER IS EXPECTED...THOUGH FOR A
PORTION OF THE OVERNIGHT HOURS CIGS ARE EXPECTED TO RISE TO VFR.
OTHERWISE...MVFR TO IFR CIGS WILL BE SEEN...ALONG WITH PERIODS OF
LIGHT PRECIP (MOSTLY RAIN TONIGHT...RA/SN MIX TUESDAY).

SOMEWHAT BLUSTERY WESTERLY WINDS THRU THE FORECAST.

&&

.MARINE...

SW WINDS WILL CONTINUE AS THE SURFACE LOW BEGINS TO PULL NORTH OF
MICHIGAN...SHIFTING THE FOCUS OF THE STRONGEST WINDS AND BIGGEST
WAVES FROM THE LAKE HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...JIT
LONG TERM...JLB
AVIATION...JIT
MARINE...JIT




000
FXUS63 KAPX 202345
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
745 PM EDT MON APR 20 2015

.SHORT TERM...(THROUGH TUESDAY)
ISSUED AT 354 PM EDT MON APR 20 2015

DRIER AIR HAS MOVED INTO THE NERN HALF OF THE CWA THIS AFTERNOON
BEHIND A 983MB SFC LOW JUST E OF LAKE SUPERIOR. LIGHT RAIN AND SNOW
SHOWERS ARE BEING OBSERVED OVER THE FANTASTIC UPPER
PENINSULA...WHILE RAIN SHOWER ARE OCCURRING FARTHER SOUTH AND EAST
OVER ERN WI AND WRN LOWER MI. THE WRAP AROUND PRECIP ON THE SW SIDE
OF THE SFC LOW WILL MOVE THROUGH THE CWA THIS EVENING BEFORE DRY AIR
SHIFTS THROUGH TONIGHT. EXPECT ALL RAIN THROUGH THIS EVENING.

AS COOLER WINDS ADVECTS INTO THE AREA FROM THE WSW BEHIND A COLD
FRONT CURRENTLY OVER ERN WI...LAKE ENHANCED/UPSLOPE/SHORTWAVE FORCED
RAIN AND SNOW ALSO BEING FORCED BY A SHORTWAVE WILL RESULT LATE
TONIGHT INTO TUE MORNING. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED
DUE TO WARM GROUND TEMPS AND 2M TEMPS ONLY FALLING INTO THE MID 30S.
SHOWERS WILL TURN TO ALL RAIN AS SFC TEMPS WARM LATE TUE MORNING
INTO TUE AFTERNOON. USED WET BULB ZERO HEIGHTS FROM THE NAM TO
DELINEATE RAIN/SNOW/MIX. HIGHS ON TUE WILL BE IN THE 40S.

&&

.LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 405 PM MON APR 20 2015

THE PATTERN THROUGH THE REST OF THE WEEK WILL BE DOMINATED BY A
MID/UPPER LEVEL LOW MOVING SLOWLY THROUGH THE NORTHERN GREAT LAKES
TOWARD SRN QUEBEC. THIS WILL BRING UNSETTLED WEATHER ALONG WITH
BELOW NORMAL TEMPERATURES.

TUE NIGHT...MODELS SUGGEST THAT A SHORTWAVE TROUGH SLIDING INTO THE
AREA WILL HELP ENHANCE THE PCPN. EXPECT THE HIGHS POPS/COVERAGE FOR
LOCATIONS FAVORED BY UPSLOPE WNW FLOW. WITH DEEP MOISTURE IN PLACE
OVER THE REGION AND 850 MB TEMPS DROPPING FROM AROUND -4C TO
-8C...THERE MAY ALSO BE ENOUGH INSTABILITY FOR SOME LAKE
ENHANCEMENT. WET-BULB ZERO HEIGHTS SUGGEST A TRANSITION FROM RAIN TO
SNOW WILL SPREAD THROUGH THE CWA FROM NW TO SE DURING THE EVENING.
SNOWFALL AMOUNTS TO AROUND AN INCH MAY BE POSSIBLE...MAINLY IN THE
HIGHER TERRAIN. WITH THE TEMPS FALLING OFF TO NEAR 30...SOME WET
SNOW/SLUSH MAY ALSO ACCUMULATE ON SOME ROADS.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN OVER OVER THE
SE CWA DURING PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE
CONTRIBUTION AS 850 MB TEMPS RANGE FROM -9C TO -12C...THE BEST
COVERAGE DURING THE DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM
LAKE SUPERIOR WHERE HEATING WILL BE STRONGEST WITH STEEP SFC-700 MB
LAPSE RATES 700 MB TEMPS TO AROUND -18C WED WILL ONLY MODERATE TO
NEAR -14C THU. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW NORMAL...IN
THE MID 30S TO AROUND 40.

FRI-MON...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH LOW(GFS/GEFS)OR NO(ECMWF) PCPN CHANCES.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 745 PM EDT MON APR 20 2015

MVFR TO IFR THIS EVENING...VFR OVERNIGHT...MVFR TUESDAY.

UNSEASONABLY STRONG LOW PRESSURE NORTH OF LAKE SUPERIOR WILL NOT BE
IN ANY HURRY TO DEPART...ONLY DRIFTING TOWARD JAMES BAY THRU TUESDAY
EVENING. PLENTY OF COOL AND MOIST AIR WILL CIRCULATE INTO THE REGION
BEHIND THE LOW. EXTENSIVE LOW CLOUD COVER IS EXPECTED...THOUGH FOR A
PORTION OF THE OVERNIGHT HOURS CIGS ARE EXPECTED TO RISE TO VFR.
OTHERWISE...MVFR TO IFR CIGS WILL BE SEEN...ALONG WITH PERIODS OF
LIGHT PRECIP (MOSTLY RAIN TONIGHT...RA/SN MIX TUESDAY).

SOMEWHAT BLUSTERY WESTERLY WINDS THRU THE FORECAST.

&&

.MARINE...

SW WINDS WILL CONTINUE AS THE SURFACE LOW BEGINS TO PULL NORTH OF
MICHIGAN...SHIFTING THE FOCUS OF THE STRONGEST WINDS AND BIGGEST
WAVES FROM THE LAKE HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...JIT
LONG TERM...JLB
AVIATION...JIT
MARINE...JIT




000
FXUS63 KAPX 202345
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
745 PM EDT MON APR 20 2015

.SHORT TERM...(THROUGH TUESDAY)
ISSUED AT 354 PM EDT MON APR 20 2015

DRIER AIR HAS MOVED INTO THE NERN HALF OF THE CWA THIS AFTERNOON
BEHIND A 983MB SFC LOW JUST E OF LAKE SUPERIOR. LIGHT RAIN AND SNOW
SHOWERS ARE BEING OBSERVED OVER THE FANTASTIC UPPER
PENINSULA...WHILE RAIN SHOWER ARE OCCURRING FARTHER SOUTH AND EAST
OVER ERN WI AND WRN LOWER MI. THE WRAP AROUND PRECIP ON THE SW SIDE
OF THE SFC LOW WILL MOVE THROUGH THE CWA THIS EVENING BEFORE DRY AIR
SHIFTS THROUGH TONIGHT. EXPECT ALL RAIN THROUGH THIS EVENING.

AS COOLER WINDS ADVECTS INTO THE AREA FROM THE WSW BEHIND A COLD
FRONT CURRENTLY OVER ERN WI...LAKE ENHANCED/UPSLOPE/SHORTWAVE FORCED
RAIN AND SNOW ALSO BEING FORCED BY A SHORTWAVE WILL RESULT LATE
TONIGHT INTO TUE MORNING. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED
DUE TO WARM GROUND TEMPS AND 2M TEMPS ONLY FALLING INTO THE MID 30S.
SHOWERS WILL TURN TO ALL RAIN AS SFC TEMPS WARM LATE TUE MORNING
INTO TUE AFTERNOON. USED WET BULB ZERO HEIGHTS FROM THE NAM TO
DELINEATE RAIN/SNOW/MIX. HIGHS ON TUE WILL BE IN THE 40S.

&&

.LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 405 PM MON APR 20 2015

THE PATTERN THROUGH THE REST OF THE WEEK WILL BE DOMINATED BY A
MID/UPPER LEVEL LOW MOVING SLOWLY THROUGH THE NORTHERN GREAT LAKES
TOWARD SRN QUEBEC. THIS WILL BRING UNSETTLED WEATHER ALONG WITH
BELOW NORMAL TEMPERATURES.

TUE NIGHT...MODELS SUGGEST THAT A SHORTWAVE TROUGH SLIDING INTO THE
AREA WILL HELP ENHANCE THE PCPN. EXPECT THE HIGHS POPS/COVERAGE FOR
LOCATIONS FAVORED BY UPSLOPE WNW FLOW. WITH DEEP MOISTURE IN PLACE
OVER THE REGION AND 850 MB TEMPS DROPPING FROM AROUND -4C TO
-8C...THERE MAY ALSO BE ENOUGH INSTABILITY FOR SOME LAKE
ENHANCEMENT. WET-BULB ZERO HEIGHTS SUGGEST A TRANSITION FROM RAIN TO
SNOW WILL SPREAD THROUGH THE CWA FROM NW TO SE DURING THE EVENING.
SNOWFALL AMOUNTS TO AROUND AN INCH MAY BE POSSIBLE...MAINLY IN THE
HIGHER TERRAIN. WITH THE TEMPS FALLING OFF TO NEAR 30...SOME WET
SNOW/SLUSH MAY ALSO ACCUMULATE ON SOME ROADS.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN OVER OVER THE
SE CWA DURING PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE
CONTRIBUTION AS 850 MB TEMPS RANGE FROM -9C TO -12C...THE BEST
COVERAGE DURING THE DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM
LAKE SUPERIOR WHERE HEATING WILL BE STRONGEST WITH STEEP SFC-700 MB
LAPSE RATES 700 MB TEMPS TO AROUND -18C WED WILL ONLY MODERATE TO
NEAR -14C THU. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW NORMAL...IN
THE MID 30S TO AROUND 40.

FRI-MON...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH LOW(GFS/GEFS)OR NO(ECMWF) PCPN CHANCES.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 745 PM EDT MON APR 20 2015

MVFR TO IFR THIS EVENING...VFR OVERNIGHT...MVFR TUESDAY.

UNSEASONABLY STRONG LOW PRESSURE NORTH OF LAKE SUPERIOR WILL NOT BE
IN ANY HURRY TO DEPART...ONLY DRIFTING TOWARD JAMES BAY THRU TUESDAY
EVENING. PLENTY OF COOL AND MOIST AIR WILL CIRCULATE INTO THE REGION
BEHIND THE LOW. EXTENSIVE LOW CLOUD COVER IS EXPECTED...THOUGH FOR A
PORTION OF THE OVERNIGHT HOURS CIGS ARE EXPECTED TO RISE TO VFR.
OTHERWISE...MVFR TO IFR CIGS WILL BE SEEN...ALONG WITH PERIODS OF
LIGHT PRECIP (MOSTLY RAIN TONIGHT...RA/SN MIX TUESDAY).

SOMEWHAT BLUSTERY WESTERLY WINDS THRU THE FORECAST.

&&

.MARINE...

SW WINDS WILL CONTINUE AS THE SURFACE LOW BEGINS TO PULL NORTH OF
MICHIGAN...SHIFTING THE FOCUS OF THE STRONGEST WINDS AND BIGGEST
WAVES FROM THE LAKE HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...JIT
LONG TERM...JLB
AVIATION...JIT
MARINE...JIT




000
FXUS63 KAPX 202345
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
745 PM EDT MON APR 20 2015

.SHORT TERM...(THROUGH TUESDAY)
ISSUED AT 354 PM EDT MON APR 20 2015

DRIER AIR HAS MOVED INTO THE NERN HALF OF THE CWA THIS AFTERNOON
BEHIND A 983MB SFC LOW JUST E OF LAKE SUPERIOR. LIGHT RAIN AND SNOW
SHOWERS ARE BEING OBSERVED OVER THE FANTASTIC UPPER
PENINSULA...WHILE RAIN SHOWER ARE OCCURRING FARTHER SOUTH AND EAST
OVER ERN WI AND WRN LOWER MI. THE WRAP AROUND PRECIP ON THE SW SIDE
OF THE SFC LOW WILL MOVE THROUGH THE CWA THIS EVENING BEFORE DRY AIR
SHIFTS THROUGH TONIGHT. EXPECT ALL RAIN THROUGH THIS EVENING.

AS COOLER WINDS ADVECTS INTO THE AREA FROM THE WSW BEHIND A COLD
FRONT CURRENTLY OVER ERN WI...LAKE ENHANCED/UPSLOPE/SHORTWAVE FORCED
RAIN AND SNOW ALSO BEING FORCED BY A SHORTWAVE WILL RESULT LATE
TONIGHT INTO TUE MORNING. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED
DUE TO WARM GROUND TEMPS AND 2M TEMPS ONLY FALLING INTO THE MID 30S.
SHOWERS WILL TURN TO ALL RAIN AS SFC TEMPS WARM LATE TUE MORNING
INTO TUE AFTERNOON. USED WET BULB ZERO HEIGHTS FROM THE NAM TO
DELINEATE RAIN/SNOW/MIX. HIGHS ON TUE WILL BE IN THE 40S.

&&

.LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 405 PM MON APR 20 2015

THE PATTERN THROUGH THE REST OF THE WEEK WILL BE DOMINATED BY A
MID/UPPER LEVEL LOW MOVING SLOWLY THROUGH THE NORTHERN GREAT LAKES
TOWARD SRN QUEBEC. THIS WILL BRING UNSETTLED WEATHER ALONG WITH
BELOW NORMAL TEMPERATURES.

TUE NIGHT...MODELS SUGGEST THAT A SHORTWAVE TROUGH SLIDING INTO THE
AREA WILL HELP ENHANCE THE PCPN. EXPECT THE HIGHS POPS/COVERAGE FOR
LOCATIONS FAVORED BY UPSLOPE WNW FLOW. WITH DEEP MOISTURE IN PLACE
OVER THE REGION AND 850 MB TEMPS DROPPING FROM AROUND -4C TO
-8C...THERE MAY ALSO BE ENOUGH INSTABILITY FOR SOME LAKE
ENHANCEMENT. WET-BULB ZERO HEIGHTS SUGGEST A TRANSITION FROM RAIN TO
SNOW WILL SPREAD THROUGH THE CWA FROM NW TO SE DURING THE EVENING.
SNOWFALL AMOUNTS TO AROUND AN INCH MAY BE POSSIBLE...MAINLY IN THE
HIGHER TERRAIN. WITH THE TEMPS FALLING OFF TO NEAR 30...SOME WET
SNOW/SLUSH MAY ALSO ACCUMULATE ON SOME ROADS.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN OVER OVER THE
SE CWA DURING PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE
CONTRIBUTION AS 850 MB TEMPS RANGE FROM -9C TO -12C...THE BEST
COVERAGE DURING THE DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM
LAKE SUPERIOR WHERE HEATING WILL BE STRONGEST WITH STEEP SFC-700 MB
LAPSE RATES 700 MB TEMPS TO AROUND -18C WED WILL ONLY MODERATE TO
NEAR -14C THU. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW NORMAL...IN
THE MID 30S TO AROUND 40.

FRI-MON...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH LOW(GFS/GEFS)OR NO(ECMWF) PCPN CHANCES.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 745 PM EDT MON APR 20 2015

MVFR TO IFR THIS EVENING...VFR OVERNIGHT...MVFR TUESDAY.

UNSEASONABLY STRONG LOW PRESSURE NORTH OF LAKE SUPERIOR WILL NOT BE
IN ANY HURRY TO DEPART...ONLY DRIFTING TOWARD JAMES BAY THRU TUESDAY
EVENING. PLENTY OF COOL AND MOIST AIR WILL CIRCULATE INTO THE REGION
BEHIND THE LOW. EXTENSIVE LOW CLOUD COVER IS EXPECTED...THOUGH FOR A
PORTION OF THE OVERNIGHT HOURS CIGS ARE EXPECTED TO RISE TO VFR.
OTHERWISE...MVFR TO IFR CIGS WILL BE SEEN...ALONG WITH PERIODS OF
LIGHT PRECIP (MOSTLY RAIN TONIGHT...RA/SN MIX TUESDAY).

SOMEWHAT BLUSTERY WESTERLY WINDS THRU THE FORECAST.

&&

.MARINE...

SW WINDS WILL CONTINUE AS THE SURFACE LOW BEGINS TO PULL NORTH OF
MICHIGAN...SHIFTING THE FOCUS OF THE STRONGEST WINDS AND BIGGEST
WAVES FROM THE LAKE HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...JIT
LONG TERM...JLB
AVIATION...JIT
MARINE...JIT




000
FXUS63 KGRR 202342
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
742 PM EDT MON APR 20 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 PM EDT MON APR 20 2015

A STALLED STORM SYSTEM OVER THE NORTHERN GREAT LAKES WILL KEEP
SHOWERS AND UNSEASONABLY COLD WEATHER THROUGH A GOOD PART OF THIS
WEEK. THE SHOWERS MAY BE MIXED WITH SNOW OR TURN TO SNOW AT TIMES
TUESDAY NIGHT INTO THURSDAY. ANY ACCUMULATIONS WILL BE MINOR.
FREEZING TEMPERATURES ARE EXPECTED EACH MORNING STARTING ON
WEDNESDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 330 PM EDT MON APR 20 2015

THE MAIN ISSUES ARE THE PRECIPITATION THREAT...THE RISK FOR SNOW
TUESDAY NIGHT INTO WEDNESDAY NIGHT AND THE GUSTY WINDS TONIGHT INTO
WEDNESDAY. OUR STALLED LOW PRESSURE SYSTEM WILL CONTINUE BRING
COLDER AIR INTO THE REGION INTO WEDNESDAY. SHORTWAVES ROTATING
AROUND THE STALLED SYSTEM WILL KEEP SHOWERS GOING THROUGH THE
SHORT TERM. WITH THE LAKE TEMPERATURE NEAR 3C... AND 850 TEMPS
FALLING TO NEAR -8C.... THAT IS MARGINAL FOR LAKE EFFECT BUT GIVEN
THERE IS ENOUGH MOISTURE IN THE 950 TO 700 MB LAYER THROUGH THIS
TIME PERIOD SHOWERS WILL CONTINUE AS WELL AS GUSTY WINDS. BY
TUESDAY NIGHT IT GETS COLD ENOUGH FOR MIXER RAIN AND SNOW AND THAT
THREAT CONTINUES INTO WEDNESDAY NIGHT.

SOME NOTE WORTHY ASPECTS TO OUR STORM SYSTEM... BASED ON THE
WESTERN REGION ENSEMBLE SITUATIONAL AWARENESS TABLE... A LOW
PRESSURE SYSTEM AS DEEP AS THIS ONE IS (984 MB AT 8 AM THIS
MORNING) HAS A RETURN PERIOD THAT IS LESS FREQUENT THAN ONCE IN 30
YEARS. HAVING 850 MB TEMPERATURES FALL INTO THE -8C TO -10C RANGE
OVER WESTERN LOWER MICHIGAN AND LAKE MICHIGAN DURING AROUND THE
21ST AND 22ND OF APRIL OCCURS ONLY ONCE IN 5 YEARS. HAVING THE 700
MB TEMPERATURE BELOW -16C HAPPENS LESS THAN ONCE IN 10 YEARS. SO
MY POINT IS THIS EVENT IS ACTUALLY A RATHER RARE EVENT FOR THIS
TIME OF YEAR IN THE GREAT LAKES.

IT SHOULD BE NOTED THE COLD TEMPERATURES (925/850/700/500 MB) FORECAST
BY THE GFS...ECMWF..THE ENSEMBLES OF BOTH...THE GEFS AND NAEFS
HAVE VERY PERSISTENT RUN AFTER RUN FOR MORE THAN A WEEK. MY POINT
HERE IS WE CAN TRUST THAT IT REALLY WILL GET AS COLD AS WE ARE
FORECASTING IT TO BE. WHICH MEANS WHEN THE 850 TEMPS FALL BELOW -6C
TOMORROW EVENING... SNOW WILL BE MORE LIKELY THAN RAIN AS A
PRECIPITATION TYPE.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 330 PM EDT MON APR 20 2015

UNSEASONABLY COOL WEATHER WILL CONTINUE THURSDAY WITH THE UPPER
TROUGH AXIS IN PLACE OVER THE EASTERN GREAT LAKES REGION AND DEEP
CYCLONIC FLOW. SCATTERED RAIN SHOWERS WILL LINGER THURSDAY AND MAY
BE MIXED AT TIMES WITH WET SNOW FLAKES PARTICULARLY ACROSS HIGHER
ELEVATIONS OF OUR NORTHERN FCST AREA.

THE UPPER TROUGH WILL SHIFT FURTHER EAST THURSDAY NIGHT AS A SFC
RIDGE BEGINS TO BUILD IN. THIS WILL LIKELY SET THE STAGE FOR A
COLDER NIGHT DEPENDING ON EXTENT AND TIMING OF CLEARING AS THE RIDGE
BEGINS TO BUILD IN. THERE IS POTENTIAL FOR WIDESPREAD TEMPS IN THE
25 TO 30 DEGREE RANGE BY EARLY FRIDAY MORNING SO FROST/FREEZE ISSUES
ARE CERTAINLY A CONCERN FOR LATE WEEK.

THE SFC HIGH PRESSURE RIDGE WILL BRING FAIR BUT COOL WEATHER FRIDAY
INTO SATURDAY. MAX TEMPS BY FRIDAY SHOULD REACH THE UPPER 40S TO
LOWER 50S WITH MIN TEMPS FRIDAY NIGHT IN THE 20S TO AROUND 30
DEGREES. TEMPERATURES WILL UNDERGO A SLOW MODERATING TREND FOR THE
WEEKEND INTO EARLY NEXT WEEK WITH FAIR WX EXPECTED TO CONTINUE WITH
THE SFC RIDGE REMAINING IN CONTROL OF THE WX PATTERN.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 741 PM EDT MON APR 20 2015

ALL TERMINALS RECENTLY CLIMBED OUT OF IFR CONDITIONS WITH MKG/AZO EVEN
AT VFR. THE BACK EDGE OF THE RAIN AREA VERY RECENTLY MOVED ONSHORE
FROM LAKE MICHIGAN...WHICH LIKELY HELPS TO EXPLAIN THE IMPROVED
CONDITIONS AT THESE WESTERN TERMINALS. HAVE TIMED THE END OF
PRECIPITATION BASED ON RADAR AND EXPECT A FAIRLY QUICK RISE INTO
VFR CEILINGS AFTERWARDS.

MENTIONED RAIN RETURNING AFTER 12Z...BUT CERTAINTY WITH TIMING
REMAINS LIMITED THIS FAR OUT. HAVE DECENT CONFIDENCE THAT CIGS
WILL REMAIN ABOVE 2000FT AGL / FUEL ALT THRESHOLDS.

&&

.MARINE...
ISSUED AT 330 PM EDT MON APR 20 2015

I EXTENDED THE AREA COVERED BY THE SCA TO COVER THE ENTIRE NEAR
SHORE. I ALSO CONTINUED IT THROUGH WEDNESDAY AFTERNOON. WITH OUR
SYSTEM STALLED OVER THE GREAT LAKES MOST OF THE WEEK WE WILL SEE A
CONTINUATION OF 15 TO 25 KNOT WINDS FROM THE SOUTHWEST INTO
TUESDAY THEN NORTHWEST TUESDAY NIGHT THROUGH A GOOD PART OF THE
REST OF THE WEEK.


&&

.HYDROLOGY...
ISSUED AT 1156 AM EDT MON APR 20 2015

WIDESPREAD RAINFALL THROUGH 8 AM THIS MORNING PRODUCED 0.50 TO 0.75
INCHES ACROSS MOST OF THE GRAND AND MUSKEGON RIVER BASINS. FURTHER
SOUTH ACROSS THE KALAMAZOO RIVER BASIN...RAINFALL AMOUNTS WERE
HIGHER IN THE 0.75 TO 1.00 INCH RANGE. AS EXPECTED...GRADUAL RIVER
RISES HAVE BEGUN ON MOST AREA RIVERS. GENERAL HYDRO THINKING HAS NOT
CHANGED MUCH...MOSTLY WITHIN BANK RISES ARE EXPECTED. A FEW SITES
COULD EXCEED BANKFULL. BUT WITH RAIN TODAY AND TONIGHT BEING OF THE
SCATTERED AND LIGHT VARIETY...SIGNIFICANT FLOODING IS NOT EXPECTED.

FORECAST RAINFALL TODAY AND TONIGHT IS IN THE 0.10 TO 0.25 INCH
RANGE. EVEN LIGHTER PRECIP AMOUNTS ARE EXPECTED TUESDAY
INTO WEDNESDAY. A SLIGHT CHANCE OF LIGHT RAIN AND SNOW WILL LINGER
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. BUT MAINLY DRY AND CHILLY
WEATHER IS EXPECTED TOWARD THE END OF THE WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...TJT
HYDROLOGY...EBW
MARINE...WDM






000
FXUS63 KGRR 202342
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
742 PM EDT MON APR 20 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 PM EDT MON APR 20 2015

A STALLED STORM SYSTEM OVER THE NORTHERN GREAT LAKES WILL KEEP
SHOWERS AND UNSEASONABLY COLD WEATHER THROUGH A GOOD PART OF THIS
WEEK. THE SHOWERS MAY BE MIXED WITH SNOW OR TURN TO SNOW AT TIMES
TUESDAY NIGHT INTO THURSDAY. ANY ACCUMULATIONS WILL BE MINOR.
FREEZING TEMPERATURES ARE EXPECTED EACH MORNING STARTING ON
WEDNESDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 330 PM EDT MON APR 20 2015

THE MAIN ISSUES ARE THE PRECIPITATION THREAT...THE RISK FOR SNOW
TUESDAY NIGHT INTO WEDNESDAY NIGHT AND THE GUSTY WINDS TONIGHT INTO
WEDNESDAY. OUR STALLED LOW PRESSURE SYSTEM WILL CONTINUE BRING
COLDER AIR INTO THE REGION INTO WEDNESDAY. SHORTWAVES ROTATING
AROUND THE STALLED SYSTEM WILL KEEP SHOWERS GOING THROUGH THE
SHORT TERM. WITH THE LAKE TEMPERATURE NEAR 3C... AND 850 TEMPS
FALLING TO NEAR -8C.... THAT IS MARGINAL FOR LAKE EFFECT BUT GIVEN
THERE IS ENOUGH MOISTURE IN THE 950 TO 700 MB LAYER THROUGH THIS
TIME PERIOD SHOWERS WILL CONTINUE AS WELL AS GUSTY WINDS. BY
TUESDAY NIGHT IT GETS COLD ENOUGH FOR MIXER RAIN AND SNOW AND THAT
THREAT CONTINUES INTO WEDNESDAY NIGHT.

SOME NOTE WORTHY ASPECTS TO OUR STORM SYSTEM... BASED ON THE
WESTERN REGION ENSEMBLE SITUATIONAL AWARENESS TABLE... A LOW
PRESSURE SYSTEM AS DEEP AS THIS ONE IS (984 MB AT 8 AM THIS
MORNING) HAS A RETURN PERIOD THAT IS LESS FREQUENT THAN ONCE IN 30
YEARS. HAVING 850 MB TEMPERATURES FALL INTO THE -8C TO -10C RANGE
OVER WESTERN LOWER MICHIGAN AND LAKE MICHIGAN DURING AROUND THE
21ST AND 22ND OF APRIL OCCURS ONLY ONCE IN 5 YEARS. HAVING THE 700
MB TEMPERATURE BELOW -16C HAPPENS LESS THAN ONCE IN 10 YEARS. SO
MY POINT IS THIS EVENT IS ACTUALLY A RATHER RARE EVENT FOR THIS
TIME OF YEAR IN THE GREAT LAKES.

IT SHOULD BE NOTED THE COLD TEMPERATURES (925/850/700/500 MB) FORECAST
BY THE GFS...ECMWF..THE ENSEMBLES OF BOTH...THE GEFS AND NAEFS
HAVE VERY PERSISTENT RUN AFTER RUN FOR MORE THAN A WEEK. MY POINT
HERE IS WE CAN TRUST THAT IT REALLY WILL GET AS COLD AS WE ARE
FORECASTING IT TO BE. WHICH MEANS WHEN THE 850 TEMPS FALL BELOW -6C
TOMORROW EVENING... SNOW WILL BE MORE LIKELY THAN RAIN AS A
PRECIPITATION TYPE.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 330 PM EDT MON APR 20 2015

UNSEASONABLY COOL WEATHER WILL CONTINUE THURSDAY WITH THE UPPER
TROUGH AXIS IN PLACE OVER THE EASTERN GREAT LAKES REGION AND DEEP
CYCLONIC FLOW. SCATTERED RAIN SHOWERS WILL LINGER THURSDAY AND MAY
BE MIXED AT TIMES WITH WET SNOW FLAKES PARTICULARLY ACROSS HIGHER
ELEVATIONS OF OUR NORTHERN FCST AREA.

THE UPPER TROUGH WILL SHIFT FURTHER EAST THURSDAY NIGHT AS A SFC
RIDGE BEGINS TO BUILD IN. THIS WILL LIKELY SET THE STAGE FOR A
COLDER NIGHT DEPENDING ON EXTENT AND TIMING OF CLEARING AS THE RIDGE
BEGINS TO BUILD IN. THERE IS POTENTIAL FOR WIDESPREAD TEMPS IN THE
25 TO 30 DEGREE RANGE BY EARLY FRIDAY MORNING SO FROST/FREEZE ISSUES
ARE CERTAINLY A CONCERN FOR LATE WEEK.

THE SFC HIGH PRESSURE RIDGE WILL BRING FAIR BUT COOL WEATHER FRIDAY
INTO SATURDAY. MAX TEMPS BY FRIDAY SHOULD REACH THE UPPER 40S TO
LOWER 50S WITH MIN TEMPS FRIDAY NIGHT IN THE 20S TO AROUND 30
DEGREES. TEMPERATURES WILL UNDERGO A SLOW MODERATING TREND FOR THE
WEEKEND INTO EARLY NEXT WEEK WITH FAIR WX EXPECTED TO CONTINUE WITH
THE SFC RIDGE REMAINING IN CONTROL OF THE WX PATTERN.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 741 PM EDT MON APR 20 2015

ALL TERMINALS RECENTLY CLIMBED OUT OF IFR CONDITIONS WITH MKG/AZO EVEN
AT VFR. THE BACK EDGE OF THE RAIN AREA VERY RECENTLY MOVED ONSHORE
FROM LAKE MICHIGAN...WHICH LIKELY HELPS TO EXPLAIN THE IMPROVED
CONDITIONS AT THESE WESTERN TERMINALS. HAVE TIMED THE END OF
PRECIPITATION BASED ON RADAR AND EXPECT A FAIRLY QUICK RISE INTO
VFR CEILINGS AFTERWARDS.

MENTIONED RAIN RETURNING AFTER 12Z...BUT CERTAINTY WITH TIMING
REMAINS LIMITED THIS FAR OUT. HAVE DECENT CONFIDENCE THAT CIGS
WILL REMAIN ABOVE 2000FT AGL / FUEL ALT THRESHOLDS.

&&

.MARINE...
ISSUED AT 330 PM EDT MON APR 20 2015

I EXTENDED THE AREA COVERED BY THE SCA TO COVER THE ENTIRE NEAR
SHORE. I ALSO CONTINUED IT THROUGH WEDNESDAY AFTERNOON. WITH OUR
SYSTEM STALLED OVER THE GREAT LAKES MOST OF THE WEEK WE WILL SEE A
CONTINUATION OF 15 TO 25 KNOT WINDS FROM THE SOUTHWEST INTO
TUESDAY THEN NORTHWEST TUESDAY NIGHT THROUGH A GOOD PART OF THE
REST OF THE WEEK.


&&

.HYDROLOGY...
ISSUED AT 1156 AM EDT MON APR 20 2015

WIDESPREAD RAINFALL THROUGH 8 AM THIS MORNING PRODUCED 0.50 TO 0.75
INCHES ACROSS MOST OF THE GRAND AND MUSKEGON RIVER BASINS. FURTHER
SOUTH ACROSS THE KALAMAZOO RIVER BASIN...RAINFALL AMOUNTS WERE
HIGHER IN THE 0.75 TO 1.00 INCH RANGE. AS EXPECTED...GRADUAL RIVER
RISES HAVE BEGUN ON MOST AREA RIVERS. GENERAL HYDRO THINKING HAS NOT
CHANGED MUCH...MOSTLY WITHIN BANK RISES ARE EXPECTED. A FEW SITES
COULD EXCEED BANKFULL. BUT WITH RAIN TODAY AND TONIGHT BEING OF THE
SCATTERED AND LIGHT VARIETY...SIGNIFICANT FLOODING IS NOT EXPECTED.

FORECAST RAINFALL TODAY AND TONIGHT IS IN THE 0.10 TO 0.25 INCH
RANGE. EVEN LIGHTER PRECIP AMOUNTS ARE EXPECTED TUESDAY
INTO WEDNESDAY. A SLIGHT CHANCE OF LIGHT RAIN AND SNOW WILL LINGER
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. BUT MAINLY DRY AND CHILLY
WEATHER IS EXPECTED TOWARD THE END OF THE WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...TJT
HYDROLOGY...EBW
MARINE...WDM







000
FXUS63 KGRR 202342
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
742 PM EDT MON APR 20 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 PM EDT MON APR 20 2015

A STALLED STORM SYSTEM OVER THE NORTHERN GREAT LAKES WILL KEEP
SHOWERS AND UNSEASONABLY COLD WEATHER THROUGH A GOOD PART OF THIS
WEEK. THE SHOWERS MAY BE MIXED WITH SNOW OR TURN TO SNOW AT TIMES
TUESDAY NIGHT INTO THURSDAY. ANY ACCUMULATIONS WILL BE MINOR.
FREEZING TEMPERATURES ARE EXPECTED EACH MORNING STARTING ON
WEDNESDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 330 PM EDT MON APR 20 2015

THE MAIN ISSUES ARE THE PRECIPITATION THREAT...THE RISK FOR SNOW
TUESDAY NIGHT INTO WEDNESDAY NIGHT AND THE GUSTY WINDS TONIGHT INTO
WEDNESDAY. OUR STALLED LOW PRESSURE SYSTEM WILL CONTINUE BRING
COLDER AIR INTO THE REGION INTO WEDNESDAY. SHORTWAVES ROTATING
AROUND THE STALLED SYSTEM WILL KEEP SHOWERS GOING THROUGH THE
SHORT TERM. WITH THE LAKE TEMPERATURE NEAR 3C... AND 850 TEMPS
FALLING TO NEAR -8C.... THAT IS MARGINAL FOR LAKE EFFECT BUT GIVEN
THERE IS ENOUGH MOISTURE IN THE 950 TO 700 MB LAYER THROUGH THIS
TIME PERIOD SHOWERS WILL CONTINUE AS WELL AS GUSTY WINDS. BY
TUESDAY NIGHT IT GETS COLD ENOUGH FOR MIXER RAIN AND SNOW AND THAT
THREAT CONTINUES INTO WEDNESDAY NIGHT.

SOME NOTE WORTHY ASPECTS TO OUR STORM SYSTEM... BASED ON THE
WESTERN REGION ENSEMBLE SITUATIONAL AWARENESS TABLE... A LOW
PRESSURE SYSTEM AS DEEP AS THIS ONE IS (984 MB AT 8 AM THIS
MORNING) HAS A RETURN PERIOD THAT IS LESS FREQUENT THAN ONCE IN 30
YEARS. HAVING 850 MB TEMPERATURES FALL INTO THE -8C TO -10C RANGE
OVER WESTERN LOWER MICHIGAN AND LAKE MICHIGAN DURING AROUND THE
21ST AND 22ND OF APRIL OCCURS ONLY ONCE IN 5 YEARS. HAVING THE 700
MB TEMPERATURE BELOW -16C HAPPENS LESS THAN ONCE IN 10 YEARS. SO
MY POINT IS THIS EVENT IS ACTUALLY A RATHER RARE EVENT FOR THIS
TIME OF YEAR IN THE GREAT LAKES.

IT SHOULD BE NOTED THE COLD TEMPERATURES (925/850/700/500 MB) FORECAST
BY THE GFS...ECMWF..THE ENSEMBLES OF BOTH...THE GEFS AND NAEFS
HAVE VERY PERSISTENT RUN AFTER RUN FOR MORE THAN A WEEK. MY POINT
HERE IS WE CAN TRUST THAT IT REALLY WILL GET AS COLD AS WE ARE
FORECASTING IT TO BE. WHICH MEANS WHEN THE 850 TEMPS FALL BELOW -6C
TOMORROW EVENING... SNOW WILL BE MORE LIKELY THAN RAIN AS A
PRECIPITATION TYPE.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 330 PM EDT MON APR 20 2015

UNSEASONABLY COOL WEATHER WILL CONTINUE THURSDAY WITH THE UPPER
TROUGH AXIS IN PLACE OVER THE EASTERN GREAT LAKES REGION AND DEEP
CYCLONIC FLOW. SCATTERED RAIN SHOWERS WILL LINGER THURSDAY AND MAY
BE MIXED AT TIMES WITH WET SNOW FLAKES PARTICULARLY ACROSS HIGHER
ELEVATIONS OF OUR NORTHERN FCST AREA.

THE UPPER TROUGH WILL SHIFT FURTHER EAST THURSDAY NIGHT AS A SFC
RIDGE BEGINS TO BUILD IN. THIS WILL LIKELY SET THE STAGE FOR A
COLDER NIGHT DEPENDING ON EXTENT AND TIMING OF CLEARING AS THE RIDGE
BEGINS TO BUILD IN. THERE IS POTENTIAL FOR WIDESPREAD TEMPS IN THE
25 TO 30 DEGREE RANGE BY EARLY FRIDAY MORNING SO FROST/FREEZE ISSUES
ARE CERTAINLY A CONCERN FOR LATE WEEK.

THE SFC HIGH PRESSURE RIDGE WILL BRING FAIR BUT COOL WEATHER FRIDAY
INTO SATURDAY. MAX TEMPS BY FRIDAY SHOULD REACH THE UPPER 40S TO
LOWER 50S WITH MIN TEMPS FRIDAY NIGHT IN THE 20S TO AROUND 30
DEGREES. TEMPERATURES WILL UNDERGO A SLOW MODERATING TREND FOR THE
WEEKEND INTO EARLY NEXT WEEK WITH FAIR WX EXPECTED TO CONTINUE WITH
THE SFC RIDGE REMAINING IN CONTROL OF THE WX PATTERN.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 741 PM EDT MON APR 20 2015

ALL TERMINALS RECENTLY CLIMBED OUT OF IFR CONDITIONS WITH MKG/AZO EVEN
AT VFR. THE BACK EDGE OF THE RAIN AREA VERY RECENTLY MOVED ONSHORE
FROM LAKE MICHIGAN...WHICH LIKELY HELPS TO EXPLAIN THE IMPROVED
CONDITIONS AT THESE WESTERN TERMINALS. HAVE TIMED THE END OF
PRECIPITATION BASED ON RADAR AND EXPECT A FAIRLY QUICK RISE INTO
VFR CEILINGS AFTERWARDS.

MENTIONED RAIN RETURNING AFTER 12Z...BUT CERTAINTY WITH TIMING
REMAINS LIMITED THIS FAR OUT. HAVE DECENT CONFIDENCE THAT CIGS
WILL REMAIN ABOVE 2000FT AGL / FUEL ALT THRESHOLDS.

&&

.MARINE...
ISSUED AT 330 PM EDT MON APR 20 2015

I EXTENDED THE AREA COVERED BY THE SCA TO COVER THE ENTIRE NEAR
SHORE. I ALSO CONTINUED IT THROUGH WEDNESDAY AFTERNOON. WITH OUR
SYSTEM STALLED OVER THE GREAT LAKES MOST OF THE WEEK WE WILL SEE A
CONTINUATION OF 15 TO 25 KNOT WINDS FROM THE SOUTHWEST INTO
TUESDAY THEN NORTHWEST TUESDAY NIGHT THROUGH A GOOD PART OF THE
REST OF THE WEEK.


&&

.HYDROLOGY...
ISSUED AT 1156 AM EDT MON APR 20 2015

WIDESPREAD RAINFALL THROUGH 8 AM THIS MORNING PRODUCED 0.50 TO 0.75
INCHES ACROSS MOST OF THE GRAND AND MUSKEGON RIVER BASINS. FURTHER
SOUTH ACROSS THE KALAMAZOO RIVER BASIN...RAINFALL AMOUNTS WERE
HIGHER IN THE 0.75 TO 1.00 INCH RANGE. AS EXPECTED...GRADUAL RIVER
RISES HAVE BEGUN ON MOST AREA RIVERS. GENERAL HYDRO THINKING HAS NOT
CHANGED MUCH...MOSTLY WITHIN BANK RISES ARE EXPECTED. A FEW SITES
COULD EXCEED BANKFULL. BUT WITH RAIN TODAY AND TONIGHT BEING OF THE
SCATTERED AND LIGHT VARIETY...SIGNIFICANT FLOODING IS NOT EXPECTED.

FORECAST RAINFALL TODAY AND TONIGHT IS IN THE 0.10 TO 0.25 INCH
RANGE. EVEN LIGHTER PRECIP AMOUNTS ARE EXPECTED TUESDAY
INTO WEDNESDAY. A SLIGHT CHANCE OF LIGHT RAIN AND SNOW WILL LINGER
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. BUT MAINLY DRY AND CHILLY
WEATHER IS EXPECTED TOWARD THE END OF THE WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...TJT
HYDROLOGY...EBW
MARINE...WDM






000
FXUS63 KGRR 202342
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
742 PM EDT MON APR 20 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 PM EDT MON APR 20 2015

A STALLED STORM SYSTEM OVER THE NORTHERN GREAT LAKES WILL KEEP
SHOWERS AND UNSEASONABLY COLD WEATHER THROUGH A GOOD PART OF THIS
WEEK. THE SHOWERS MAY BE MIXED WITH SNOW OR TURN TO SNOW AT TIMES
TUESDAY NIGHT INTO THURSDAY. ANY ACCUMULATIONS WILL BE MINOR.
FREEZING TEMPERATURES ARE EXPECTED EACH MORNING STARTING ON
WEDNESDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 330 PM EDT MON APR 20 2015

THE MAIN ISSUES ARE THE PRECIPITATION THREAT...THE RISK FOR SNOW
TUESDAY NIGHT INTO WEDNESDAY NIGHT AND THE GUSTY WINDS TONIGHT INTO
WEDNESDAY. OUR STALLED LOW PRESSURE SYSTEM WILL CONTINUE BRING
COLDER AIR INTO THE REGION INTO WEDNESDAY. SHORTWAVES ROTATING
AROUND THE STALLED SYSTEM WILL KEEP SHOWERS GOING THROUGH THE
SHORT TERM. WITH THE LAKE TEMPERATURE NEAR 3C... AND 850 TEMPS
FALLING TO NEAR -8C.... THAT IS MARGINAL FOR LAKE EFFECT BUT GIVEN
THERE IS ENOUGH MOISTURE IN THE 950 TO 700 MB LAYER THROUGH THIS
TIME PERIOD SHOWERS WILL CONTINUE AS WELL AS GUSTY WINDS. BY
TUESDAY NIGHT IT GETS COLD ENOUGH FOR MIXER RAIN AND SNOW AND THAT
THREAT CONTINUES INTO WEDNESDAY NIGHT.

SOME NOTE WORTHY ASPECTS TO OUR STORM SYSTEM... BASED ON THE
WESTERN REGION ENSEMBLE SITUATIONAL AWARENESS TABLE... A LOW
PRESSURE SYSTEM AS DEEP AS THIS ONE IS (984 MB AT 8 AM THIS
MORNING) HAS A RETURN PERIOD THAT IS LESS FREQUENT THAN ONCE IN 30
YEARS. HAVING 850 MB TEMPERATURES FALL INTO THE -8C TO -10C RANGE
OVER WESTERN LOWER MICHIGAN AND LAKE MICHIGAN DURING AROUND THE
21ST AND 22ND OF APRIL OCCURS ONLY ONCE IN 5 YEARS. HAVING THE 700
MB TEMPERATURE BELOW -16C HAPPENS LESS THAN ONCE IN 10 YEARS. SO
MY POINT IS THIS EVENT IS ACTUALLY A RATHER RARE EVENT FOR THIS
TIME OF YEAR IN THE GREAT LAKES.

IT SHOULD BE NOTED THE COLD TEMPERATURES (925/850/700/500 MB) FORECAST
BY THE GFS...ECMWF..THE ENSEMBLES OF BOTH...THE GEFS AND NAEFS
HAVE VERY PERSISTENT RUN AFTER RUN FOR MORE THAN A WEEK. MY POINT
HERE IS WE CAN TRUST THAT IT REALLY WILL GET AS COLD AS WE ARE
FORECASTING IT TO BE. WHICH MEANS WHEN THE 850 TEMPS FALL BELOW -6C
TOMORROW EVENING... SNOW WILL BE MORE LIKELY THAN RAIN AS A
PRECIPITATION TYPE.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 330 PM EDT MON APR 20 2015

UNSEASONABLY COOL WEATHER WILL CONTINUE THURSDAY WITH THE UPPER
TROUGH AXIS IN PLACE OVER THE EASTERN GREAT LAKES REGION AND DEEP
CYCLONIC FLOW. SCATTERED RAIN SHOWERS WILL LINGER THURSDAY AND MAY
BE MIXED AT TIMES WITH WET SNOW FLAKES PARTICULARLY ACROSS HIGHER
ELEVATIONS OF OUR NORTHERN FCST AREA.

THE UPPER TROUGH WILL SHIFT FURTHER EAST THURSDAY NIGHT AS A SFC
RIDGE BEGINS TO BUILD IN. THIS WILL LIKELY SET THE STAGE FOR A
COLDER NIGHT DEPENDING ON EXTENT AND TIMING OF CLEARING AS THE RIDGE
BEGINS TO BUILD IN. THERE IS POTENTIAL FOR WIDESPREAD TEMPS IN THE
25 TO 30 DEGREE RANGE BY EARLY FRIDAY MORNING SO FROST/FREEZE ISSUES
ARE CERTAINLY A CONCERN FOR LATE WEEK.

THE SFC HIGH PRESSURE RIDGE WILL BRING FAIR BUT COOL WEATHER FRIDAY
INTO SATURDAY. MAX TEMPS BY FRIDAY SHOULD REACH THE UPPER 40S TO
LOWER 50S WITH MIN TEMPS FRIDAY NIGHT IN THE 20S TO AROUND 30
DEGREES. TEMPERATURES WILL UNDERGO A SLOW MODERATING TREND FOR THE
WEEKEND INTO EARLY NEXT WEEK WITH FAIR WX EXPECTED TO CONTINUE WITH
THE SFC RIDGE REMAINING IN CONTROL OF THE WX PATTERN.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 741 PM EDT MON APR 20 2015

ALL TERMINALS RECENTLY CLIMBED OUT OF IFR CONDITIONS WITH MKG/AZO EVEN
AT VFR. THE BACK EDGE OF THE RAIN AREA VERY RECENTLY MOVED ONSHORE
FROM LAKE MICHIGAN...WHICH LIKELY HELPS TO EXPLAIN THE IMPROVED
CONDITIONS AT THESE WESTERN TERMINALS. HAVE TIMED THE END OF
PRECIPITATION BASED ON RADAR AND EXPECT A FAIRLY QUICK RISE INTO
VFR CEILINGS AFTERWARDS.

MENTIONED RAIN RETURNING AFTER 12Z...BUT CERTAINTY WITH TIMING
REMAINS LIMITED THIS FAR OUT. HAVE DECENT CONFIDENCE THAT CIGS
WILL REMAIN ABOVE 2000FT AGL / FUEL ALT THRESHOLDS.

&&

.MARINE...
ISSUED AT 330 PM EDT MON APR 20 2015

I EXTENDED THE AREA COVERED BY THE SCA TO COVER THE ENTIRE NEAR
SHORE. I ALSO CONTINUED IT THROUGH WEDNESDAY AFTERNOON. WITH OUR
SYSTEM STALLED OVER THE GREAT LAKES MOST OF THE WEEK WE WILL SEE A
CONTINUATION OF 15 TO 25 KNOT WINDS FROM THE SOUTHWEST INTO
TUESDAY THEN NORTHWEST TUESDAY NIGHT THROUGH A GOOD PART OF THE
REST OF THE WEEK.


&&

.HYDROLOGY...
ISSUED AT 1156 AM EDT MON APR 20 2015

WIDESPREAD RAINFALL THROUGH 8 AM THIS MORNING PRODUCED 0.50 TO 0.75
INCHES ACROSS MOST OF THE GRAND AND MUSKEGON RIVER BASINS. FURTHER
SOUTH ACROSS THE KALAMAZOO RIVER BASIN...RAINFALL AMOUNTS WERE
HIGHER IN THE 0.75 TO 1.00 INCH RANGE. AS EXPECTED...GRADUAL RIVER
RISES HAVE BEGUN ON MOST AREA RIVERS. GENERAL HYDRO THINKING HAS NOT
CHANGED MUCH...MOSTLY WITHIN BANK RISES ARE EXPECTED. A FEW SITES
COULD EXCEED BANKFULL. BUT WITH RAIN TODAY AND TONIGHT BEING OF THE
SCATTERED AND LIGHT VARIETY...SIGNIFICANT FLOODING IS NOT EXPECTED.

FORECAST RAINFALL TODAY AND TONIGHT IS IN THE 0.10 TO 0.25 INCH
RANGE. EVEN LIGHTER PRECIP AMOUNTS ARE EXPECTED TUESDAY
INTO WEDNESDAY. A SLIGHT CHANCE OF LIGHT RAIN AND SNOW WILL LINGER
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. BUT MAINLY DRY AND CHILLY
WEATHER IS EXPECTED TOWARD THE END OF THE WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...TJT
HYDROLOGY...EBW
MARINE...WDM







000
FXUS63 KDTX 202302
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
702 PM EDT MON APR 20 2015


.AVIATION...

THERE HAS BEEN SOME SLIGHT DECREASE IN WIND SPEEDS OVER THE LAST
COUPLE OF HOURS. ONGOING LOW LEVEL COLD AIR ADVECTION SHOULD KEEP
SOME DEGREE OF GUSTINESS TO THE WINDS DURING THE FIRST HOUR OR TWO
OF THE TAF FORECAST. THERE SHOULD THEN BE SOME DEGREE OF DECOUPLING
IN THE BOUNDARY LAYER DURING THE EVENING WHICH WILL DECREASE WIND
SPEEDS FURTHER AND HELP SUPPRESS SOME OF THE GUSTINESS. AN AXIS OF
LOW LEVEL MOISTURE WILL TRACK ACROSS SE MI THIS EVENING...SUSTAINING
SOME RESIDUAL LIGHT SHOWERS AND MVFR BASED CEILINGS. CEILINGS WILL
LIFT DURING THE OVERNIGHT AS THE DEPTH OF COLD AIR DRAMATICALLY
INCREASES ACROSS SRN MI. RAPID DEEPENING OF THE DAYTIME MIXED LAYER
WILL LEAD TO STRONG SW WINDS LATE TUES MORNING THROUGH TUES
AFTERNOON. THE CURRENT SET OF OF TAFS ACCOUNTS FOR SOME POTENTIAL
FOR STRONG CONVECTIVE WIND GUSTS OUT OF AFTERNOON SHOWERS ON TUES.
THIS STILL LOOKS REASONABLE.

FOR DTW...IN LIGHT OF CURRENT OBSERVATIONS...THERE IS A CHANCE THAT
CEILINGS WILL DROP BELOW 2K FT BRIEFLY THIS EVENING. THE BETTER LOW
LEVEL MOISTURE WILL LIFT NORTH OF METRO OVERNIGHT...POSSIBLY OPENING
THE DOOR FOR SOME BRIEF CLEARING TOWARD DAYBREAK. CONFIDENCE OF THIS
IS NOT HIGH ENOUGH TO ADD A PERIOD OF CLEAR SKIES ATTM.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS BELOW 5000 FT THIS EVENING. LOW OVERNIGHT AND
  TUESDAY.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS TUESDAY
  AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 346 PM EDT MON APR 20 2015

SHORT TERM...TONIGHT

MUCAPES DID REACH 500 TO 800 J/KG EARLIER THIS AFTERNOON (PER LAPS
DATA)...WHICH WAS ABLE TO SUPPORT A COUPLE THUNDERSTORMS OVER
SOUTHEAST MICHIGAN. BULK OF CONVECTIVE ACTIVITY HAS PUSHED
EAST...AND CONTINUED DRYING BEHIND THE COLD FRONT WILL OCCUR...AS
SURFACE DEW PTS CRASH INTO THE 40S. WITH THAT COLDER/DRY AIR PUSH
IS SOME GUSTY WINDS...AS SOME PEAK WINDS OF 35 TO 45 MPH CAN BE
EXPECTED FOR ANOTHER COUPLE OF HOURS AS WE EXIT PEAK HEATING.
NOTED PEAK WIND AT DTW OF 42 KNOTS AT 1855Z. NAM/GFS MODEL
SOUNDINGS/LOW LEVEL RH FIELDS SUGGEST WE ARE GOING TO PARTIALLY
CLEAR OUT TONIGHT...BUT UPSTREAM OBSERVATIONS EXTENDING BACK WEST
OVER THE WESTERN GREAT LAKES/UPPER MISSISSIPPI RIVER VALLEY TO NOT
LOOK VERY ENCOURAGING...AND PREFERENCE WAS TO INCREASE THE CLOUD
COVER FORECAST FOR TONIGHT WITH THE COLD CYCLONIC FLOW. ALSO...AS
850 MB TEMPS FALL INTO THE MID NEGATIVE SINGLE NUMBERS OVER LAKE
MICHIGAN...SOME LAKE MICHIGAN MOISTURE/INSTABILITY CONTRIBUTION IS
NOT OUT OF THE QUESTION. HAVE CARRIED ISOLATED-SCATTERED LIGHT
RAIN SHOWER MENTION TO ACCOUNT FOR LINGERING ACTIVITY LATE THIS
AFTERNOON/EARLY THIS EVENING AND THEN THE POSSIBLE ACTIVITY TOWARD
MORNING. DESPITE CLOUDS...COLD ADVECTION EXPECTED TO SEND MINS
INTO THE UPPER 30S TO LOWER 40S.

LONG TERM...

A BROAD UPPER LEVEL TROUGH WITH A CLOSED LOW IN CLOSE PROXIMITY TO
THE GREAT LAKES REGION WILL KEEP SOUTHEASTERN MICHIGAN UNDER THE
INFLUENCE OF COLD CYCLONIC FLOW THROUGHOUT THE MIDWEEK PERIOD.
NATURE OF INDIVIDUAL SHORTWAVES ROTATING AROUND THIS UPPER LEVEL
FEATURE KEEPS THE SPECIFIC TIMING CONFIDENCE INHERENTLY LOW.

MAGNITUDE OF COLD AND DRY AIR ADVECTION FROM TONIGHT WILL
PRECONDITION THE ATMOSPHERE AND ALLOW FOR THE GROWTH OF A DEEP
DIURNAL NEAR SURFACE MIXED LAYER ON TUESDAY. FORECAST SOUNDINGS
SUGGEST MIXING HEIGHTS REACHING AS HIGH AS 6 TO 7 KFT AGL BY THE
AFTERNOON HOURS. GEOSTROPHIC FLOW IN THE REGION WILL REMAIN ELEVATED
WITH THE LOW HEIGHT ANOMALY OVER CENTRAL ONTARIO WHICH SUPPORTS
WIDESPREAD WESTERLY WIND GUSTS LATE TUESDAY MORNING/TUESDAY
AFTERNOON IN EXCESS OF 30 KNOTS. COMBINATION OF SHORTWAVE ENERGY
WORKING THROUGH THE TROUGH AXIS AND SPOKES OF ENHANCED MIDLEVEL
CONVERGENCE/SATURATION WILL BRING THE POTENTIAL FOR RAIN SHOWERS BY
TUESDAY MORNING. POTENTIAL MEDIUM IMPACT WEATHER SCENARIO MAY
UNFOLD...CONTINGENT ON OVERALL EFFICIENCY OF INDIVIDUAL CONVECTIVE
CIRCULATIONS OF THE SHOWERS TO ENHANCE DOWNWARD MOMENTUM TRANSPORT.
AFOREMENTIONED FORECAST DISCUSSION MADE REFERENCE TO A CLASSIC
INVERTED V STRUCTURE...WHICH SUGGESTS SOME POSSIBILITY THAT
WINDGUSTS COULD REACH 50 MPH. FUTURE SHIFTS CAN ASSESS THE
FEASIBILITY OF A POSSIBLE WIND ADVISORY FOR WEDNESDAY AFTERNOON.

PERSISTENT CYCLONIC FLOW AROUND UPPER LEVEL CLOSED LOW WILL BRING
ANOTHER DAY OF COLD AND SHOWERY TO SOUTHEASTERN MICHIGAN ON
WEDNESDAY. A SECONDARY SURGE OF COLD AIR ADVECTION IS FORECASTED
BETWEEN 15-18Z. THE CAA SHOULD WORK AGAINST DIURNAL HEATING...WITH
HIGHS SOME 7 TO 10 DEGREES COOLER THAN THE DAY BEFORE. HIGHS ON
WEDNESDAY ARE ONLY EXPECTED TO REACH THE MIDDLE TO UPPER 40S. BETTER
MESSAGE TO COMMUNICATE IS THAT WIND CHILLS FOR MANY AREAS WILL NOT
CLIMB OUT OF THE 30S.

THE REGION WILL STILL BE UNDER THE INFLUENCE OF LONGWAVE TROUGHING
ON THURSDAY BEFORE WEAK UPPER LEVEL RIDGING BUILDS IN FOR THE START
OF THE WEEKEND.  THIS TROUGH WILL CONTINUE TO LEAD TO COOLER TEMPS
THURSDAY BEFORE TEMPERATURES MODERATE A TINY BIT BACK INTO THE 50S
BY THE WEEKEND.  AT THIS POINT THE ONLY POTENTIAL FOR POSSIBLE
PRECIP IN THE EXTENDED WOULD BE ON SATURDAY...ALTHOUGH MOST MODELS
ARE KEEPING THE BULK OF THE PRECIP SOUTH OF THE CWA WITH THE
EXCEPTION OF THE 12Z ECMWF.

MARINE...

STRONG SOUTHWESTERLY WIND FIELD IS NOW IN PLACE WITH WINDSPEEDS AREA
WIDE RANGING BETWEEN 25 AND 35 KNOTS. SMALL CRAFT ADVISORIES REMAIN
IN EFFECT FOR ALL NEARSHORE ZONES. BREEZY WESTERLY WINDS WILL
PERSIST THROUGH MIDWEEK AS CONDITIONS REMAIN RELATIVELY STATIC WITH
LOW PRESSURE PARKED OVER THE GREAT LAKES. ADDITIONAL SMALL CRAFT
ADVISORIES FOR WIND WILL LIKELY BE NEEDED ON TUESDAY AND POSSIBLY
ONCE MORE ON WEDNESDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LHZ421-422-
     441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LEZ444.

&&

$$

AVIATION.....SC
SHORT TERM...SF
LONG TERM....CB/SS
MARINE.......CB


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).




000
FXUS63 KDTX 202302
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
702 PM EDT MON APR 20 2015


.AVIATION...

THERE HAS BEEN SOME SLIGHT DECREASE IN WIND SPEEDS OVER THE LAST
COUPLE OF HOURS. ONGOING LOW LEVEL COLD AIR ADVECTION SHOULD KEEP
SOME DEGREE OF GUSTINESS TO THE WINDS DURING THE FIRST HOUR OR TWO
OF THE TAF FORECAST. THERE SHOULD THEN BE SOME DEGREE OF DECOUPLING
IN THE BOUNDARY LAYER DURING THE EVENING WHICH WILL DECREASE WIND
SPEEDS FURTHER AND HELP SUPPRESS SOME OF THE GUSTINESS. AN AXIS OF
LOW LEVEL MOISTURE WILL TRACK ACROSS SE MI THIS EVENING...SUSTAINING
SOME RESIDUAL LIGHT SHOWERS AND MVFR BASED CEILINGS. CEILINGS WILL
LIFT DURING THE OVERNIGHT AS THE DEPTH OF COLD AIR DRAMATICALLY
INCREASES ACROSS SRN MI. RAPID DEEPENING OF THE DAYTIME MIXED LAYER
WILL LEAD TO STRONG SW WINDS LATE TUES MORNING THROUGH TUES
AFTERNOON. THE CURRENT SET OF OF TAFS ACCOUNTS FOR SOME POTENTIAL
FOR STRONG CONVECTIVE WIND GUSTS OUT OF AFTERNOON SHOWERS ON TUES.
THIS STILL LOOKS REASONABLE.

FOR DTW...IN LIGHT OF CURRENT OBSERVATIONS...THERE IS A CHANCE THAT
CEILINGS WILL DROP BELOW 2K FT BRIEFLY THIS EVENING. THE BETTER LOW
LEVEL MOISTURE WILL LIFT NORTH OF METRO OVERNIGHT...POSSIBLY OPENING
THE DOOR FOR SOME BRIEF CLEARING TOWARD DAYBREAK. CONFIDENCE OF THIS
IS NOT HIGH ENOUGH TO ADD A PERIOD OF CLEAR SKIES ATTM.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS BELOW 5000 FT THIS EVENING. LOW OVERNIGHT AND
  TUESDAY.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS TUESDAY
  AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 346 PM EDT MON APR 20 2015

SHORT TERM...TONIGHT

MUCAPES DID REACH 500 TO 800 J/KG EARLIER THIS AFTERNOON (PER LAPS
DATA)...WHICH WAS ABLE TO SUPPORT A COUPLE THUNDERSTORMS OVER
SOUTHEAST MICHIGAN. BULK OF CONVECTIVE ACTIVITY HAS PUSHED
EAST...AND CONTINUED DRYING BEHIND THE COLD FRONT WILL OCCUR...AS
SURFACE DEW PTS CRASH INTO THE 40S. WITH THAT COLDER/DRY AIR PUSH
IS SOME GUSTY WINDS...AS SOME PEAK WINDS OF 35 TO 45 MPH CAN BE
EXPECTED FOR ANOTHER COUPLE OF HOURS AS WE EXIT PEAK HEATING.
NOTED PEAK WIND AT DTW OF 42 KNOTS AT 1855Z. NAM/GFS MODEL
SOUNDINGS/LOW LEVEL RH FIELDS SUGGEST WE ARE GOING TO PARTIALLY
CLEAR OUT TONIGHT...BUT UPSTREAM OBSERVATIONS EXTENDING BACK WEST
OVER THE WESTERN GREAT LAKES/UPPER MISSISSIPPI RIVER VALLEY TO NOT
LOOK VERY ENCOURAGING...AND PREFERENCE WAS TO INCREASE THE CLOUD
COVER FORECAST FOR TONIGHT WITH THE COLD CYCLONIC FLOW. ALSO...AS
850 MB TEMPS FALL INTO THE MID NEGATIVE SINGLE NUMBERS OVER LAKE
MICHIGAN...SOME LAKE MICHIGAN MOISTURE/INSTABILITY CONTRIBUTION IS
NOT OUT OF THE QUESTION. HAVE CARRIED ISOLATED-SCATTERED LIGHT
RAIN SHOWER MENTION TO ACCOUNT FOR LINGERING ACTIVITY LATE THIS
AFTERNOON/EARLY THIS EVENING AND THEN THE POSSIBLE ACTIVITY TOWARD
MORNING. DESPITE CLOUDS...COLD ADVECTION EXPECTED TO SEND MINS
INTO THE UPPER 30S TO LOWER 40S.

LONG TERM...

A BROAD UPPER LEVEL TROUGH WITH A CLOSED LOW IN CLOSE PROXIMITY TO
THE GREAT LAKES REGION WILL KEEP SOUTHEASTERN MICHIGAN UNDER THE
INFLUENCE OF COLD CYCLONIC FLOW THROUGHOUT THE MIDWEEK PERIOD.
NATURE OF INDIVIDUAL SHORTWAVES ROTATING AROUND THIS UPPER LEVEL
FEATURE KEEPS THE SPECIFIC TIMING CONFIDENCE INHERENTLY LOW.

MAGNITUDE OF COLD AND DRY AIR ADVECTION FROM TONIGHT WILL
PRECONDITION THE ATMOSPHERE AND ALLOW FOR THE GROWTH OF A DEEP
DIURNAL NEAR SURFACE MIXED LAYER ON TUESDAY. FORECAST SOUNDINGS
SUGGEST MIXING HEIGHTS REACHING AS HIGH AS 6 TO 7 KFT AGL BY THE
AFTERNOON HOURS. GEOSTROPHIC FLOW IN THE REGION WILL REMAIN ELEVATED
WITH THE LOW HEIGHT ANOMALY OVER CENTRAL ONTARIO WHICH SUPPORTS
WIDESPREAD WESTERLY WIND GUSTS LATE TUESDAY MORNING/TUESDAY
AFTERNOON IN EXCESS OF 30 KNOTS. COMBINATION OF SHORTWAVE ENERGY
WORKING THROUGH THE TROUGH AXIS AND SPOKES OF ENHANCED MIDLEVEL
CONVERGENCE/SATURATION WILL BRING THE POTENTIAL FOR RAIN SHOWERS BY
TUESDAY MORNING. POTENTIAL MEDIUM IMPACT WEATHER SCENARIO MAY
UNFOLD...CONTINGENT ON OVERALL EFFICIENCY OF INDIVIDUAL CONVECTIVE
CIRCULATIONS OF THE SHOWERS TO ENHANCE DOWNWARD MOMENTUM TRANSPORT.
AFOREMENTIONED FORECAST DISCUSSION MADE REFERENCE TO A CLASSIC
INVERTED V STRUCTURE...WHICH SUGGESTS SOME POSSIBILITY THAT
WINDGUSTS COULD REACH 50 MPH. FUTURE SHIFTS CAN ASSESS THE
FEASIBILITY OF A POSSIBLE WIND ADVISORY FOR WEDNESDAY AFTERNOON.

PERSISTENT CYCLONIC FLOW AROUND UPPER LEVEL CLOSED LOW WILL BRING
ANOTHER DAY OF COLD AND SHOWERY TO SOUTHEASTERN MICHIGAN ON
WEDNESDAY. A SECONDARY SURGE OF COLD AIR ADVECTION IS FORECASTED
BETWEEN 15-18Z. THE CAA SHOULD WORK AGAINST DIURNAL HEATING...WITH
HIGHS SOME 7 TO 10 DEGREES COOLER THAN THE DAY BEFORE. HIGHS ON
WEDNESDAY ARE ONLY EXPECTED TO REACH THE MIDDLE TO UPPER 40S. BETTER
MESSAGE TO COMMUNICATE IS THAT WIND CHILLS FOR MANY AREAS WILL NOT
CLIMB OUT OF THE 30S.

THE REGION WILL STILL BE UNDER THE INFLUENCE OF LONGWAVE TROUGHING
ON THURSDAY BEFORE WEAK UPPER LEVEL RIDGING BUILDS IN FOR THE START
OF THE WEEKEND.  THIS TROUGH WILL CONTINUE TO LEAD TO COOLER TEMPS
THURSDAY BEFORE TEMPERATURES MODERATE A TINY BIT BACK INTO THE 50S
BY THE WEEKEND.  AT THIS POINT THE ONLY POTENTIAL FOR POSSIBLE
PRECIP IN THE EXTENDED WOULD BE ON SATURDAY...ALTHOUGH MOST MODELS
ARE KEEPING THE BULK OF THE PRECIP SOUTH OF THE CWA WITH THE
EXCEPTION OF THE 12Z ECMWF.

MARINE...

STRONG SOUTHWESTERLY WIND FIELD IS NOW IN PLACE WITH WINDSPEEDS AREA
WIDE RANGING BETWEEN 25 AND 35 KNOTS. SMALL CRAFT ADVISORIES REMAIN
IN EFFECT FOR ALL NEARSHORE ZONES. BREEZY WESTERLY WINDS WILL
PERSIST THROUGH MIDWEEK AS CONDITIONS REMAIN RELATIVELY STATIC WITH
LOW PRESSURE PARKED OVER THE GREAT LAKES. ADDITIONAL SMALL CRAFT
ADVISORIES FOR WIND WILL LIKELY BE NEEDED ON TUESDAY AND POSSIBLY
ONCE MORE ON WEDNESDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LHZ421-422-
     441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LEZ444.

&&

$$

AVIATION.....SC
SHORT TERM...SF
LONG TERM....CB/SS
MARINE.......CB


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).




000
FXUS63 KDTX 202302
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
702 PM EDT MON APR 20 2015


.AVIATION...

THERE HAS BEEN SOME SLIGHT DECREASE IN WIND SPEEDS OVER THE LAST
COUPLE OF HOURS. ONGOING LOW LEVEL COLD AIR ADVECTION SHOULD KEEP
SOME DEGREE OF GUSTINESS TO THE WINDS DURING THE FIRST HOUR OR TWO
OF THE TAF FORECAST. THERE SHOULD THEN BE SOME DEGREE OF DECOUPLING
IN THE BOUNDARY LAYER DURING THE EVENING WHICH WILL DECREASE WIND
SPEEDS FURTHER AND HELP SUPPRESS SOME OF THE GUSTINESS. AN AXIS OF
LOW LEVEL MOISTURE WILL TRACK ACROSS SE MI THIS EVENING...SUSTAINING
SOME RESIDUAL LIGHT SHOWERS AND MVFR BASED CEILINGS. CEILINGS WILL
LIFT DURING THE OVERNIGHT AS THE DEPTH OF COLD AIR DRAMATICALLY
INCREASES ACROSS SRN MI. RAPID DEEPENING OF THE DAYTIME MIXED LAYER
WILL LEAD TO STRONG SW WINDS LATE TUES MORNING THROUGH TUES
AFTERNOON. THE CURRENT SET OF OF TAFS ACCOUNTS FOR SOME POTENTIAL
FOR STRONG CONVECTIVE WIND GUSTS OUT OF AFTERNOON SHOWERS ON TUES.
THIS STILL LOOKS REASONABLE.

FOR DTW...IN LIGHT OF CURRENT OBSERVATIONS...THERE IS A CHANCE THAT
CEILINGS WILL DROP BELOW 2K FT BRIEFLY THIS EVENING. THE BETTER LOW
LEVEL MOISTURE WILL LIFT NORTH OF METRO OVERNIGHT...POSSIBLY OPENING
THE DOOR FOR SOME BRIEF CLEARING TOWARD DAYBREAK. CONFIDENCE OF THIS
IS NOT HIGH ENOUGH TO ADD A PERIOD OF CLEAR SKIES ATTM.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS BELOW 5000 FT THIS EVENING. LOW OVERNIGHT AND
  TUESDAY.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS TUESDAY
  AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 346 PM EDT MON APR 20 2015

SHORT TERM...TONIGHT

MUCAPES DID REACH 500 TO 800 J/KG EARLIER THIS AFTERNOON (PER LAPS
DATA)...WHICH WAS ABLE TO SUPPORT A COUPLE THUNDERSTORMS OVER
SOUTHEAST MICHIGAN. BULK OF CONVECTIVE ACTIVITY HAS PUSHED
EAST...AND CONTINUED DRYING BEHIND THE COLD FRONT WILL OCCUR...AS
SURFACE DEW PTS CRASH INTO THE 40S. WITH THAT COLDER/DRY AIR PUSH
IS SOME GUSTY WINDS...AS SOME PEAK WINDS OF 35 TO 45 MPH CAN BE
EXPECTED FOR ANOTHER COUPLE OF HOURS AS WE EXIT PEAK HEATING.
NOTED PEAK WIND AT DTW OF 42 KNOTS AT 1855Z. NAM/GFS MODEL
SOUNDINGS/LOW LEVEL RH FIELDS SUGGEST WE ARE GOING TO PARTIALLY
CLEAR OUT TONIGHT...BUT UPSTREAM OBSERVATIONS EXTENDING BACK WEST
OVER THE WESTERN GREAT LAKES/UPPER MISSISSIPPI RIVER VALLEY TO NOT
LOOK VERY ENCOURAGING...AND PREFERENCE WAS TO INCREASE THE CLOUD
COVER FORECAST FOR TONIGHT WITH THE COLD CYCLONIC FLOW. ALSO...AS
850 MB TEMPS FALL INTO THE MID NEGATIVE SINGLE NUMBERS OVER LAKE
MICHIGAN...SOME LAKE MICHIGAN MOISTURE/INSTABILITY CONTRIBUTION IS
NOT OUT OF THE QUESTION. HAVE CARRIED ISOLATED-SCATTERED LIGHT
RAIN SHOWER MENTION TO ACCOUNT FOR LINGERING ACTIVITY LATE THIS
AFTERNOON/EARLY THIS EVENING AND THEN THE POSSIBLE ACTIVITY TOWARD
MORNING. DESPITE CLOUDS...COLD ADVECTION EXPECTED TO SEND MINS
INTO THE UPPER 30S TO LOWER 40S.

LONG TERM...

A BROAD UPPER LEVEL TROUGH WITH A CLOSED LOW IN CLOSE PROXIMITY TO
THE GREAT LAKES REGION WILL KEEP SOUTHEASTERN MICHIGAN UNDER THE
INFLUENCE OF COLD CYCLONIC FLOW THROUGHOUT THE MIDWEEK PERIOD.
NATURE OF INDIVIDUAL SHORTWAVES ROTATING AROUND THIS UPPER LEVEL
FEATURE KEEPS THE SPECIFIC TIMING CONFIDENCE INHERENTLY LOW.

MAGNITUDE OF COLD AND DRY AIR ADVECTION FROM TONIGHT WILL
PRECONDITION THE ATMOSPHERE AND ALLOW FOR THE GROWTH OF A DEEP
DIURNAL NEAR SURFACE MIXED LAYER ON TUESDAY. FORECAST SOUNDINGS
SUGGEST MIXING HEIGHTS REACHING AS HIGH AS 6 TO 7 KFT AGL BY THE
AFTERNOON HOURS. GEOSTROPHIC FLOW IN THE REGION WILL REMAIN ELEVATED
WITH THE LOW HEIGHT ANOMALY OVER CENTRAL ONTARIO WHICH SUPPORTS
WIDESPREAD WESTERLY WIND GUSTS LATE TUESDAY MORNING/TUESDAY
AFTERNOON IN EXCESS OF 30 KNOTS. COMBINATION OF SHORTWAVE ENERGY
WORKING THROUGH THE TROUGH AXIS AND SPOKES OF ENHANCED MIDLEVEL
CONVERGENCE/SATURATION WILL BRING THE POTENTIAL FOR RAIN SHOWERS BY
TUESDAY MORNING. POTENTIAL MEDIUM IMPACT WEATHER SCENARIO MAY
UNFOLD...CONTINGENT ON OVERALL EFFICIENCY OF INDIVIDUAL CONVECTIVE
CIRCULATIONS OF THE SHOWERS TO ENHANCE DOWNWARD MOMENTUM TRANSPORT.
AFOREMENTIONED FORECAST DISCUSSION MADE REFERENCE TO A CLASSIC
INVERTED V STRUCTURE...WHICH SUGGESTS SOME POSSIBILITY THAT
WINDGUSTS COULD REACH 50 MPH. FUTURE SHIFTS CAN ASSESS THE
FEASIBILITY OF A POSSIBLE WIND ADVISORY FOR WEDNESDAY AFTERNOON.

PERSISTENT CYCLONIC FLOW AROUND UPPER LEVEL CLOSED LOW WILL BRING
ANOTHER DAY OF COLD AND SHOWERY TO SOUTHEASTERN MICHIGAN ON
WEDNESDAY. A SECONDARY SURGE OF COLD AIR ADVECTION IS FORECASTED
BETWEEN 15-18Z. THE CAA SHOULD WORK AGAINST DIURNAL HEATING...WITH
HIGHS SOME 7 TO 10 DEGREES COOLER THAN THE DAY BEFORE. HIGHS ON
WEDNESDAY ARE ONLY EXPECTED TO REACH THE MIDDLE TO UPPER 40S. BETTER
MESSAGE TO COMMUNICATE IS THAT WIND CHILLS FOR MANY AREAS WILL NOT
CLIMB OUT OF THE 30S.

THE REGION WILL STILL BE UNDER THE INFLUENCE OF LONGWAVE TROUGHING
ON THURSDAY BEFORE WEAK UPPER LEVEL RIDGING BUILDS IN FOR THE START
OF THE WEEKEND.  THIS TROUGH WILL CONTINUE TO LEAD TO COOLER TEMPS
THURSDAY BEFORE TEMPERATURES MODERATE A TINY BIT BACK INTO THE 50S
BY THE WEEKEND.  AT THIS POINT THE ONLY POTENTIAL FOR POSSIBLE
PRECIP IN THE EXTENDED WOULD BE ON SATURDAY...ALTHOUGH MOST MODELS
ARE KEEPING THE BULK OF THE PRECIP SOUTH OF THE CWA WITH THE
EXCEPTION OF THE 12Z ECMWF.

MARINE...

STRONG SOUTHWESTERLY WIND FIELD IS NOW IN PLACE WITH WINDSPEEDS AREA
WIDE RANGING BETWEEN 25 AND 35 KNOTS. SMALL CRAFT ADVISORIES REMAIN
IN EFFECT FOR ALL NEARSHORE ZONES. BREEZY WESTERLY WINDS WILL
PERSIST THROUGH MIDWEEK AS CONDITIONS REMAIN RELATIVELY STATIC WITH
LOW PRESSURE PARKED OVER THE GREAT LAKES. ADDITIONAL SMALL CRAFT
ADVISORIES FOR WIND WILL LIKELY BE NEEDED ON TUESDAY AND POSSIBLY
ONCE MORE ON WEDNESDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LHZ421-422-
     441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LEZ444.

&&

$$

AVIATION.....SC
SHORT TERM...SF
LONG TERM....CB/SS
MARINE.......CB


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).



000
FXUS63 KDTX 202302
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
702 PM EDT MON APR 20 2015


.AVIATION...

THERE HAS BEEN SOME SLIGHT DECREASE IN WIND SPEEDS OVER THE LAST
COUPLE OF HOURS. ONGOING LOW LEVEL COLD AIR ADVECTION SHOULD KEEP
SOME DEGREE OF GUSTINESS TO THE WINDS DURING THE FIRST HOUR OR TWO
OF THE TAF FORECAST. THERE SHOULD THEN BE SOME DEGREE OF DECOUPLING
IN THE BOUNDARY LAYER DURING THE EVENING WHICH WILL DECREASE WIND
SPEEDS FURTHER AND HELP SUPPRESS SOME OF THE GUSTINESS. AN AXIS OF
LOW LEVEL MOISTURE WILL TRACK ACROSS SE MI THIS EVENING...SUSTAINING
SOME RESIDUAL LIGHT SHOWERS AND MVFR BASED CEILINGS. CEILINGS WILL
LIFT DURING THE OVERNIGHT AS THE DEPTH OF COLD AIR DRAMATICALLY
INCREASES ACROSS SRN MI. RAPID DEEPENING OF THE DAYTIME MIXED LAYER
WILL LEAD TO STRONG SW WINDS LATE TUES MORNING THROUGH TUES
AFTERNOON. THE CURRENT SET OF OF TAFS ACCOUNTS FOR SOME POTENTIAL
FOR STRONG CONVECTIVE WIND GUSTS OUT OF AFTERNOON SHOWERS ON TUES.
THIS STILL LOOKS REASONABLE.

FOR DTW...IN LIGHT OF CURRENT OBSERVATIONS...THERE IS A CHANCE THAT
CEILINGS WILL DROP BELOW 2K FT BRIEFLY THIS EVENING. THE BETTER LOW
LEVEL MOISTURE WILL LIFT NORTH OF METRO OVERNIGHT...POSSIBLY OPENING
THE DOOR FOR SOME BRIEF CLEARING TOWARD DAYBREAK. CONFIDENCE OF THIS
IS NOT HIGH ENOUGH TO ADD A PERIOD OF CLEAR SKIES ATTM.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS BELOW 5000 FT THIS EVENING. LOW OVERNIGHT AND
  TUESDAY.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS TUESDAY
  AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 346 PM EDT MON APR 20 2015

SHORT TERM...TONIGHT

MUCAPES DID REACH 500 TO 800 J/KG EARLIER THIS AFTERNOON (PER LAPS
DATA)...WHICH WAS ABLE TO SUPPORT A COUPLE THUNDERSTORMS OVER
SOUTHEAST MICHIGAN. BULK OF CONVECTIVE ACTIVITY HAS PUSHED
EAST...AND CONTINUED DRYING BEHIND THE COLD FRONT WILL OCCUR...AS
SURFACE DEW PTS CRASH INTO THE 40S. WITH THAT COLDER/DRY AIR PUSH
IS SOME GUSTY WINDS...AS SOME PEAK WINDS OF 35 TO 45 MPH CAN BE
EXPECTED FOR ANOTHER COUPLE OF HOURS AS WE EXIT PEAK HEATING.
NOTED PEAK WIND AT DTW OF 42 KNOTS AT 1855Z. NAM/GFS MODEL
SOUNDINGS/LOW LEVEL RH FIELDS SUGGEST WE ARE GOING TO PARTIALLY
CLEAR OUT TONIGHT...BUT UPSTREAM OBSERVATIONS EXTENDING BACK WEST
OVER THE WESTERN GREAT LAKES/UPPER MISSISSIPPI RIVER VALLEY TO NOT
LOOK VERY ENCOURAGING...AND PREFERENCE WAS TO INCREASE THE CLOUD
COVER FORECAST FOR TONIGHT WITH THE COLD CYCLONIC FLOW. ALSO...AS
850 MB TEMPS FALL INTO THE MID NEGATIVE SINGLE NUMBERS OVER LAKE
MICHIGAN...SOME LAKE MICHIGAN MOISTURE/INSTABILITY CONTRIBUTION IS
NOT OUT OF THE QUESTION. HAVE CARRIED ISOLATED-SCATTERED LIGHT
RAIN SHOWER MENTION TO ACCOUNT FOR LINGERING ACTIVITY LATE THIS
AFTERNOON/EARLY THIS EVENING AND THEN THE POSSIBLE ACTIVITY TOWARD
MORNING. DESPITE CLOUDS...COLD ADVECTION EXPECTED TO SEND MINS
INTO THE UPPER 30S TO LOWER 40S.

LONG TERM...

A BROAD UPPER LEVEL TROUGH WITH A CLOSED LOW IN CLOSE PROXIMITY TO
THE GREAT LAKES REGION WILL KEEP SOUTHEASTERN MICHIGAN UNDER THE
INFLUENCE OF COLD CYCLONIC FLOW THROUGHOUT THE MIDWEEK PERIOD.
NATURE OF INDIVIDUAL SHORTWAVES ROTATING AROUND THIS UPPER LEVEL
FEATURE KEEPS THE SPECIFIC TIMING CONFIDENCE INHERENTLY LOW.

MAGNITUDE OF COLD AND DRY AIR ADVECTION FROM TONIGHT WILL
PRECONDITION THE ATMOSPHERE AND ALLOW FOR THE GROWTH OF A DEEP
DIURNAL NEAR SURFACE MIXED LAYER ON TUESDAY. FORECAST SOUNDINGS
SUGGEST MIXING HEIGHTS REACHING AS HIGH AS 6 TO 7 KFT AGL BY THE
AFTERNOON HOURS. GEOSTROPHIC FLOW IN THE REGION WILL REMAIN ELEVATED
WITH THE LOW HEIGHT ANOMALY OVER CENTRAL ONTARIO WHICH SUPPORTS
WIDESPREAD WESTERLY WIND GUSTS LATE TUESDAY MORNING/TUESDAY
AFTERNOON IN EXCESS OF 30 KNOTS. COMBINATION OF SHORTWAVE ENERGY
WORKING THROUGH THE TROUGH AXIS AND SPOKES OF ENHANCED MIDLEVEL
CONVERGENCE/SATURATION WILL BRING THE POTENTIAL FOR RAIN SHOWERS BY
TUESDAY MORNING. POTENTIAL MEDIUM IMPACT WEATHER SCENARIO MAY
UNFOLD...CONTINGENT ON OVERALL EFFICIENCY OF INDIVIDUAL CONVECTIVE
CIRCULATIONS OF THE SHOWERS TO ENHANCE DOWNWARD MOMENTUM TRANSPORT.
AFOREMENTIONED FORECAST DISCUSSION MADE REFERENCE TO A CLASSIC
INVERTED V STRUCTURE...WHICH SUGGESTS SOME POSSIBILITY THAT
WINDGUSTS COULD REACH 50 MPH. FUTURE SHIFTS CAN ASSESS THE
FEASIBILITY OF A POSSIBLE WIND ADVISORY FOR WEDNESDAY AFTERNOON.

PERSISTENT CYCLONIC FLOW AROUND UPPER LEVEL CLOSED LOW WILL BRING
ANOTHER DAY OF COLD AND SHOWERY TO SOUTHEASTERN MICHIGAN ON
WEDNESDAY. A SECONDARY SURGE OF COLD AIR ADVECTION IS FORECASTED
BETWEEN 15-18Z. THE CAA SHOULD WORK AGAINST DIURNAL HEATING...WITH
HIGHS SOME 7 TO 10 DEGREES COOLER THAN THE DAY BEFORE. HIGHS ON
WEDNESDAY ARE ONLY EXPECTED TO REACH THE MIDDLE TO UPPER 40S. BETTER
MESSAGE TO COMMUNICATE IS THAT WIND CHILLS FOR MANY AREAS WILL NOT
CLIMB OUT OF THE 30S.

THE REGION WILL STILL BE UNDER THE INFLUENCE OF LONGWAVE TROUGHING
ON THURSDAY BEFORE WEAK UPPER LEVEL RIDGING BUILDS IN FOR THE START
OF THE WEEKEND.  THIS TROUGH WILL CONTINUE TO LEAD TO COOLER TEMPS
THURSDAY BEFORE TEMPERATURES MODERATE A TINY BIT BACK INTO THE 50S
BY THE WEEKEND.  AT THIS POINT THE ONLY POTENTIAL FOR POSSIBLE
PRECIP IN THE EXTENDED WOULD BE ON SATURDAY...ALTHOUGH MOST MODELS
ARE KEEPING THE BULK OF THE PRECIP SOUTH OF THE CWA WITH THE
EXCEPTION OF THE 12Z ECMWF.

MARINE...

STRONG SOUTHWESTERLY WIND FIELD IS NOW IN PLACE WITH WINDSPEEDS AREA
WIDE RANGING BETWEEN 25 AND 35 KNOTS. SMALL CRAFT ADVISORIES REMAIN
IN EFFECT FOR ALL NEARSHORE ZONES. BREEZY WESTERLY WINDS WILL
PERSIST THROUGH MIDWEEK AS CONDITIONS REMAIN RELATIVELY STATIC WITH
LOW PRESSURE PARKED OVER THE GREAT LAKES. ADDITIONAL SMALL CRAFT
ADVISORIES FOR WIND WILL LIKELY BE NEEDED ON TUESDAY AND POSSIBLY
ONCE MORE ON WEDNESDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LHZ421-422-
     441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LEZ444.

&&

$$

AVIATION.....SC
SHORT TERM...SF
LONG TERM....CB/SS
MARINE.......CB


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).



000
FXUS63 KGRR 202010 CCA
AFDGRR

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
333 PM EDT MON APR 20 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE

.SYNOPSIS...
ISSUED AT 330 PM EDT MON APR 20 2015

A STALLED STORM SYSTEM OVER THE NORTHERN GREAT LAKES WILL KEEP
SHOWERS AND UNSEASONABLY COLD WEATHER THROUGH A GOOD PART OF THIS
WEEK. THE SHOWERS MAY BE MIXED WITH SNOW OR TURN TO SNOW AT TIMES
TUESDAY NIGHT INTO THURSDAY. ANY ACCUMULATIONS WILL BE MINOR.
FREEZING TEMPERATURES ARE EXPECTED EACH MORNING STARTING ON
WEDNESDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 330 PM EDT MON APR 20 2015


THE MAIN ISSUES ARE THE PRECIPITATION THREAT...THE RISK FOR SNOW
TUESDAY NIGHT INTO WEDNESDAY NIGHT AND THE GUSTY WINDS TONIGHT INTO
WEDNESDAY. OUR STALLED LOW PRESSURE SYSTEM WILL CONTINUE BRING
COLDER AIR INTO THE REGION INTO WEDNESDAY. SHORTWAVES ROTATING
AROUND THE STALLED SYSTEM WILL KEEP SHOWERS GOING THROUGH THE
SHORT TERM. WITH THE LAKE TEMPERATURE NEAR 3C... AND 850 TEMPS
FALLING TO NEAR -8C.... THAT IS MARGINAL FOR LAKE EFFECT BUT GIVEN
THERE IS ENOUGH MOISTURE IN THE 950 TO 700 MB LAYER THROUGH THIS
TIME PERIOD SHOWERS WILL CONTINUE AS WELL AS GUSTY WINDS. BY
TUESDAY NIGHT IT GETS COLD ENOUGH FOR MIXER RAIN AND SNOW AND THAT
THREAT CONTINUES INTO WEDNESDAY NIGHT.

SOME NOTE WORTHY ASPECTS TO OUR STORM SYSTEM... BASED ON THE
WESTERN REGION ENSEMBLE SITUATIONAL AWARENESS TABLE... A LOW
PRESSURE SYSTEM AS DEEP AS THIS ONE IS (984 MB AT 8 AM THIS
MORNING) HAS A RETURN PERIOD THAT IS LESS FREQUENT THAN ONCE IN 30
YEARS. HAVING 850 MB TEMPERATURES FALL INTO THE -8C TO -10C RANGE
OVER WESTERN LOWER MICHIGAN AND LAKE MICHIGAN DURING AROUND THE
21ST AND 22ND OF APRIL OCCURS ONLY ONCE IN 5 YEARS. HAVING THE 700
MB TEMPERATURE BELOW -16C HAPPENS LESS THAN ONCE IN 10 YEARS. SO
MY POINT IS THIS EVENT IS ACTUALLY A RATHER RARE EVENT FOR THIS
TIME OF YEAR IN THE GREAT LAKES.

IT SHOULD BE NOTED THE COLD TEMPERATURES (925/850/700/500 MB) FORECAST
BY THE GFS...ECMWF..THE ENSEMBLES OF BOTH...THE GEFS AND NAEFS
HAVE VERY PERSISTENT RUN AFTER RUN FOR MORE THAN A WEEK. MY POINT
HERE IS WE CAN TRUST THAT IT REALLY WILL GET AS COLD AS WE ARE
FORECASTING IT TO BE. WHICH MEANS WHEN THE 850 TEMPS FALL BELOW -6C
TOMORROW EVENING... SNOW WILL BE MORE LIKELY THAN RAIN AS A
PRECIPITATION TYPE.




.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 330 PM EDT MON APR 20 2015

UNSEASONABLY COOL WEATHER WILL CONTINUE THURSDAY WITH THE UPPER
TROUGH AXIS IN PLACE OVER THE EASTERN GREAT LAKES REGION AND DEEP
CYCLONIC FLOW. SCATTERED RAIN SHOWERS WILL LINGER THURSDAY AND MAY
BE MIXED AT TIMES WITH WET SNOW FLAKES PARTICULARLY ACROSS HIGHER
ELEVATIONS OF OUR NORTHERN FCST AREA.

THE UPPER TROUGH WILL SHIFT FURTHER EAST THURSDAY NIGHT AS A SFC
RIDGE BEGINS TO BUILD IN. THIS WILL LIKELY SET THE STAGE FOR A
COLDER NIGHT DEPENDING ON EXTENT AND TIMING OF CLEARING AS THE RIDGE
BEGINS TO BUILD IN. THERE IS POTENTIAL FOR WIDESPREAD TEMPS IN THE
25 TO 30 DEGREE RANGE BY EARLY FRIDAY MORNING SO FROST/FREEZE ISSUES
ARE CERTAINLY A CONCERN FOR LATE WEEK.

THE SFC HIGH PRESSURE RIDGE WILL BRING FAIR BUT COOL WEATHER FRIDAY
INTO SATURDAY. MAX TEMPS BY FRIDAY SHOULD REACH THE UPPER 40S TO
LOWER 50S WITH MIN TEMPS FRIDAY NIGHT IN THE 20S TO AROUND 30
DEGREES. TEMPERATURES WILL UNDERGO A SLOW MODERATING TREND FOR THE
WEEKEND INTO EARLY NEXT WEEK WITH FAIR WX EXPECTED TO CONTINUE WITH
THE SFC RIDGE REMAINING IN CONTROL OF THE WX PATTERN.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY)
ISSUED AT 1220 PM EDT MON APR 20 2015

MAINLY IFR/MVFR CONDITIONS WILL CONTINUE THROUGH MID TO LATE
AFTERNOON DUE TO LOW CIGS AND SCATTERED SHOWERS AND PATCHY FOG
BEFORE GRADUALLY IMPROVING TO VFR THIS EVENING AND OVERNIGHT.

IT WILL BE BREEZY THIS AFTERNOON WITH SW WINDS OF 15 TO 25 KTS WITH
GUSTS TO AROUND 30 KTS. SOUTHWEST TO WEST WINDS WILL STAY UP AROUND
15 TO 25 KTS OVERNIGHT AND THEN VEER TO THE WEST AND INCREASE TO 20
TO 25 KTS WITH GUSTS TO AROUND 30 KTS BY MID TO LATE TUESDAY MORNING.

SCATTERED LIGHT RAIN SHOWERS WILL LINGER OVERNIGHT AND THEN BECOME
MORE PREVALENT ON TUESDAY. MAINLY VFR CONDITIONS ARE ANTICIPATED
TUESDAY ALTHOUGH SOME PATCHY MVFR IS POSSIBLE DUE TO LOWER CIGS AND
HEAVIER SHOWERS.


&&

.MARINE...
ISSUED AT 330 PM EDT MON APR 20 2015

I EXTENDED THE AREA COVERED BY THE SCA TO COVER THE ENTIRE NEAR
SHORE. I ALSO CONTINUED IT THROUGH WEDNESDAY AFTERNOON. WITH OUR
SYSTEM STALLED OVER THE GREAT LAKES MOST OF THE WEEK WE WILL SEE A
CONTINUATION OF 15 TO 25 KNOT WINDS FROM THE SOUTHWEST INTO
TUESDAY THEN NORTHWEST TUESDAY NIGHT THROUGH A GOOD PART OF THE
REST OF THE WEEK.

&&

.HYDROLOGY...
ISSUED AT 1156 AM EDT MON APR 20 2015

WIDESPREAD RAINFALL THROUGH 8 AM THIS MORNING PRODUCED 0.50 TO 0.75
INCHES ACROSS MOST OF THE GRAND AND MUSKEGON RIVER BASINS. FURTHER
SOUTH ACROSS THE KALAMAZOO RIVER BASIN...RAINFALL AMOUNTS WERE
HIGHER IN THE 0.75 TO 1.00 INCH RANGE. AS EXPECTED...GRADUAL RIVER
RISES HAVE BEGUN ON MOST AREA RIVERS. GENERAL HYDRO THINKING HAS NOT
CHANGED MUCH...MOSTLY WITHIN BANK RISES ARE EXPECTED. A FEW SITES
COULD EXCEED BANKFULL. BUT WITH RAIN TODAY AND TONIGHT BEING OF THE
SCATTERED AND LIGHT VARIETY...SIGNIFICANT FLOODING IS NOT EXPECTED.

FORECAST RAINFALL TODAY AND TONIGHT IS IN THE 0.10 TO 0.25 INCH
RANGE. EVEN LIGHTER PRECIP AMOUNTS ARE EXPECTED TUESDAY
INTO WEDNESDAY. A SLIGHT CHANCE OF LIGHT RAIN AND SNOW WILL LINGER
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. BUT MAINLY DRY AND CHILLY
WEATHER IS EXPECTED TOWARD THE END OF THE WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...LAURENS
HYDROLOGY...EBW
MARINE...WDM









000
FXUS63 KGRR 202010 CCA
AFDGRR

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
333 PM EDT MON APR 20 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE

.SYNOPSIS...
ISSUED AT 330 PM EDT MON APR 20 2015

A STALLED STORM SYSTEM OVER THE NORTHERN GREAT LAKES WILL KEEP
SHOWERS AND UNSEASONABLY COLD WEATHER THROUGH A GOOD PART OF THIS
WEEK. THE SHOWERS MAY BE MIXED WITH SNOW OR TURN TO SNOW AT TIMES
TUESDAY NIGHT INTO THURSDAY. ANY ACCUMULATIONS WILL BE MINOR.
FREEZING TEMPERATURES ARE EXPECTED EACH MORNING STARTING ON
WEDNESDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 330 PM EDT MON APR 20 2015


THE MAIN ISSUES ARE THE PRECIPITATION THREAT...THE RISK FOR SNOW
TUESDAY NIGHT INTO WEDNESDAY NIGHT AND THE GUSTY WINDS TONIGHT INTO
WEDNESDAY. OUR STALLED LOW PRESSURE SYSTEM WILL CONTINUE BRING
COLDER AIR INTO THE REGION INTO WEDNESDAY. SHORTWAVES ROTATING
AROUND THE STALLED SYSTEM WILL KEEP SHOWERS GOING THROUGH THE
SHORT TERM. WITH THE LAKE TEMPERATURE NEAR 3C... AND 850 TEMPS
FALLING TO NEAR -8C.... THAT IS MARGINAL FOR LAKE EFFECT BUT GIVEN
THERE IS ENOUGH MOISTURE IN THE 950 TO 700 MB LAYER THROUGH THIS
TIME PERIOD SHOWERS WILL CONTINUE AS WELL AS GUSTY WINDS. BY
TUESDAY NIGHT IT GETS COLD ENOUGH FOR MIXER RAIN AND SNOW AND THAT
THREAT CONTINUES INTO WEDNESDAY NIGHT.

SOME NOTE WORTHY ASPECTS TO OUR STORM SYSTEM... BASED ON THE
WESTERN REGION ENSEMBLE SITUATIONAL AWARENESS TABLE... A LOW
PRESSURE SYSTEM AS DEEP AS THIS ONE IS (984 MB AT 8 AM THIS
MORNING) HAS A RETURN PERIOD THAT IS LESS FREQUENT THAN ONCE IN 30
YEARS. HAVING 850 MB TEMPERATURES FALL INTO THE -8C TO -10C RANGE
OVER WESTERN LOWER MICHIGAN AND LAKE MICHIGAN DURING AROUND THE
21ST AND 22ND OF APRIL OCCURS ONLY ONCE IN 5 YEARS. HAVING THE 700
MB TEMPERATURE BELOW -16C HAPPENS LESS THAN ONCE IN 10 YEARS. SO
MY POINT IS THIS EVENT IS ACTUALLY A RATHER RARE EVENT FOR THIS
TIME OF YEAR IN THE GREAT LAKES.

IT SHOULD BE NOTED THE COLD TEMPERATURES (925/850/700/500 MB) FORECAST
BY THE GFS...ECMWF..THE ENSEMBLES OF BOTH...THE GEFS AND NAEFS
HAVE VERY PERSISTENT RUN AFTER RUN FOR MORE THAN A WEEK. MY POINT
HERE IS WE CAN TRUST THAT IT REALLY WILL GET AS COLD AS WE ARE
FORECASTING IT TO BE. WHICH MEANS WHEN THE 850 TEMPS FALL BELOW -6C
TOMORROW EVENING... SNOW WILL BE MORE LIKELY THAN RAIN AS A
PRECIPITATION TYPE.




.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 330 PM EDT MON APR 20 2015

UNSEASONABLY COOL WEATHER WILL CONTINUE THURSDAY WITH THE UPPER
TROUGH AXIS IN PLACE OVER THE EASTERN GREAT LAKES REGION AND DEEP
CYCLONIC FLOW. SCATTERED RAIN SHOWERS WILL LINGER THURSDAY AND MAY
BE MIXED AT TIMES WITH WET SNOW FLAKES PARTICULARLY ACROSS HIGHER
ELEVATIONS OF OUR NORTHERN FCST AREA.

THE UPPER TROUGH WILL SHIFT FURTHER EAST THURSDAY NIGHT AS A SFC
RIDGE BEGINS TO BUILD IN. THIS WILL LIKELY SET THE STAGE FOR A
COLDER NIGHT DEPENDING ON EXTENT AND TIMING OF CLEARING AS THE RIDGE
BEGINS TO BUILD IN. THERE IS POTENTIAL FOR WIDESPREAD TEMPS IN THE
25 TO 30 DEGREE RANGE BY EARLY FRIDAY MORNING SO FROST/FREEZE ISSUES
ARE CERTAINLY A CONCERN FOR LATE WEEK.

THE SFC HIGH PRESSURE RIDGE WILL BRING FAIR BUT COOL WEATHER FRIDAY
INTO SATURDAY. MAX TEMPS BY FRIDAY SHOULD REACH THE UPPER 40S TO
LOWER 50S WITH MIN TEMPS FRIDAY NIGHT IN THE 20S TO AROUND 30
DEGREES. TEMPERATURES WILL UNDERGO A SLOW MODERATING TREND FOR THE
WEEKEND INTO EARLY NEXT WEEK WITH FAIR WX EXPECTED TO CONTINUE WITH
THE SFC RIDGE REMAINING IN CONTROL OF THE WX PATTERN.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY)
ISSUED AT 1220 PM EDT MON APR 20 2015

MAINLY IFR/MVFR CONDITIONS WILL CONTINUE THROUGH MID TO LATE
AFTERNOON DUE TO LOW CIGS AND SCATTERED SHOWERS AND PATCHY FOG
BEFORE GRADUALLY IMPROVING TO VFR THIS EVENING AND OVERNIGHT.

IT WILL BE BREEZY THIS AFTERNOON WITH SW WINDS OF 15 TO 25 KTS WITH
GUSTS TO AROUND 30 KTS. SOUTHWEST TO WEST WINDS WILL STAY UP AROUND
15 TO 25 KTS OVERNIGHT AND THEN VEER TO THE WEST AND INCREASE TO 20
TO 25 KTS WITH GUSTS TO AROUND 30 KTS BY MID TO LATE TUESDAY MORNING.

SCATTERED LIGHT RAIN SHOWERS WILL LINGER OVERNIGHT AND THEN BECOME
MORE PREVALENT ON TUESDAY. MAINLY VFR CONDITIONS ARE ANTICIPATED
TUESDAY ALTHOUGH SOME PATCHY MVFR IS POSSIBLE DUE TO LOWER CIGS AND
HEAVIER SHOWERS.


&&

.MARINE...
ISSUED AT 330 PM EDT MON APR 20 2015

I EXTENDED THE AREA COVERED BY THE SCA TO COVER THE ENTIRE NEAR
SHORE. I ALSO CONTINUED IT THROUGH WEDNESDAY AFTERNOON. WITH OUR
SYSTEM STALLED OVER THE GREAT LAKES MOST OF THE WEEK WE WILL SEE A
CONTINUATION OF 15 TO 25 KNOT WINDS FROM THE SOUTHWEST INTO
TUESDAY THEN NORTHWEST TUESDAY NIGHT THROUGH A GOOD PART OF THE
REST OF THE WEEK.

&&

.HYDROLOGY...
ISSUED AT 1156 AM EDT MON APR 20 2015

WIDESPREAD RAINFALL THROUGH 8 AM THIS MORNING PRODUCED 0.50 TO 0.75
INCHES ACROSS MOST OF THE GRAND AND MUSKEGON RIVER BASINS. FURTHER
SOUTH ACROSS THE KALAMAZOO RIVER BASIN...RAINFALL AMOUNTS WERE
HIGHER IN THE 0.75 TO 1.00 INCH RANGE. AS EXPECTED...GRADUAL RIVER
RISES HAVE BEGUN ON MOST AREA RIVERS. GENERAL HYDRO THINKING HAS NOT
CHANGED MUCH...MOSTLY WITHIN BANK RISES ARE EXPECTED. A FEW SITES
COULD EXCEED BANKFULL. BUT WITH RAIN TODAY AND TONIGHT BEING OF THE
SCATTERED AND LIGHT VARIETY...SIGNIFICANT FLOODING IS NOT EXPECTED.

FORECAST RAINFALL TODAY AND TONIGHT IS IN THE 0.10 TO 0.25 INCH
RANGE. EVEN LIGHTER PRECIP AMOUNTS ARE EXPECTED TUESDAY
INTO WEDNESDAY. A SLIGHT CHANCE OF LIGHT RAIN AND SNOW WILL LINGER
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. BUT MAINLY DRY AND CHILLY
WEATHER IS EXPECTED TOWARD THE END OF THE WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...LAURENS
HYDROLOGY...EBW
MARINE...WDM








000
FXUS63 KAPX 202004
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
ISSUED BY NATIONAL WEATHER SERVICE MARQUETTE MI
405 PM EDT MON APR 20 2015

.SHORT TERM...(THROUGH TUESDAY)
ISSUED AT 354 PM EDT MON APR 20 2015

DRIER AIR HAS MOVED INTO THE NERN HALF OF THE CWA THIS AFTERNOON
BEHIND A 983MB SFC LOW JUST E OF LAKE SUPERIOR. LIGHT RAIN AND SNOW
SHOWERS ARE BEING OBSERVED OVER THE FANTASTIC UPPER
PENINSULA...WHILE RAIN SHOWER ARE OCCURING FARTHER SOUTH AND EAST
OVER ERN WI AND WRN LOWER MI. THE WRAP AROUND PRECIP ON THE SW SIDE
OF THE SFC LOW WILL MOVE THROUGH THE CWA THIS EVENING BEFORE DRY AIR
SHIFTS THROUGH TONIGHT. EXPECT ALL RAIN THROUGH THIS EVENING.

AS COOLER WINDS ADVECTS INTO THE AREA FROM THE WSW BEHIND A COLD
FRONT CURRENTLY OVER ERN WI...LAKE ENHANCED/UPSLOPE/SHORTWAVE FORCED
RAIN AND SNOW ALSO BEING FORCED BY A SHORTWAVE WILL RESULT LATE
TONIGHT INTO TUE MORNING. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED
DUE TO WARM GROUND TEMPS AND 2M TEMPS ONLY FALLING INTO THE MID 30S.
SHOWERS WILL TURN TO ALL RAIN AS SFC TEMPS WARM LATE TUE MORNING
INTO TUE AFTERNOON. USED WET BULB ZERO HEIGHTS FROM THE NAM TO
DELINEATE RAIN/SNOW/MIX. HIGHS ON TUE WILL BE IN THE 40S.

&&

.LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 405 PM MON APR 20 2015

THE PATTERN THROUGH THE REST OF THE WEEK WILL BE DOMINATED BY A
MID/UPPER LEVEL LOW MOVING SLOWLY THROUGH THE NORTHERN GREAT LAKES
TOWARD SRN QUEBEC. THIS WILL BRING UNSETTLED WEATHER ALONG WITH
BELOW NORMAL TEMPERATURES.

TUE NIGHT...MODELS SUGGEST THAT A SHORTWAVE TROUGH SLIDING INTO THE
AREA WILL HELP ENHANCE THE PCPN. EXPECT THE HIGHS POPS/COVERAGE FOR
LOCATIONS FAVORED BY UPSLOPE WNW FLOW. WITH DEEP MOISTURE IN PLACE
OVER THE REGION AND 850 MB TEMPS DROPPING FROM AROUND -4C TO
-8C...THERE MAY ALSO BE ENOUGH INSTABILITY FOR SOME LAKE
ENHANCEMENT. WET-BULB ZERO HEIGHTS SUGGEST A TRANSITION FROM RAIN TO
SNOW WILL SPREAD THROUGH THE CWA FROM NW TO SE DURING THE EVENING.
SNOWFALL AMOUNTS TO AROUND AN INCH MAY BE POSSIBLE...MAINLY IN THE
HIGHER TERRAIN. WITH THE TEMPS FALLING OFF TO NEAR 30...SOME WET
SNOW/SLUSH MAY ALSO ACCUMULATE ON SOME ROADS.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN OVER OVER THE
SE CWA DURING PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE
CONTRIBUTION AS 850 MB TEMPS RANGE FROM -9C TO -12C...THE BEST
COVERAGE DURING THE DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM
LAKE SUPERIOR WHERE HEATING WILL BE STRONGEST WITH STEEP SFC-700 MB
LAPSE RATES 700 MB TEMPS TO AROUND -18C WED WILL ONLY MODERATE TO
NEAR -14C THU. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW NORMAL...IN
THE MID 30S TO AROUND 40.

FRI-MON...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH LOW(GFS/GEFS)OR NO(ECMWF) PCPN CHANCES.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 145 PM EDT MON APR 20 2015

EXPECT IMPROVEMENT AT ALL SITES THIS EVENING INTO TONIGHT AS DRIER
AIR MOVES INTO THE AREA. CONDITIONS WILL THEN DETERIORATE TUE
MORNING AS ANOTHER ROUND OF MOISTURE MOVES IN WITH AN UPPER LEVEL
DISTURBANCE. EXACT TIMING AND MAGNITUDE OF DETERIORATING CONDITIONS
ON TUE IS UNCERTAIN AT THIS TIME.

&&

.MARINE...

SW WINDS WILL CONTINUE AS THE SURFACE LOW BEGINS TO PULL NORTH OF
MICHIGAN...SHIFTING THE FOCUS OF THE STRONGEST WINDS AND BIGGEST
WAVES FROM THE LAKE HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...JIT
LONG TERM...JLB
AVIATION...JIT
MARINE...JIT



000
FXUS63 KAPX 202004
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
ISSUED BY NATIONAL WEATHER SERVICE MARQUETTE MI
405 PM EDT MON APR 20 2015

.SHORT TERM...(THROUGH TUESDAY)
ISSUED AT 354 PM EDT MON APR 20 2015

DRIER AIR HAS MOVED INTO THE NERN HALF OF THE CWA THIS AFTERNOON
BEHIND A 983MB SFC LOW JUST E OF LAKE SUPERIOR. LIGHT RAIN AND SNOW
SHOWERS ARE BEING OBSERVED OVER THE FANTASTIC UPPER
PENINSULA...WHILE RAIN SHOWER ARE OCCURING FARTHER SOUTH AND EAST
OVER ERN WI AND WRN LOWER MI. THE WRAP AROUND PRECIP ON THE SW SIDE
OF THE SFC LOW WILL MOVE THROUGH THE CWA THIS EVENING BEFORE DRY AIR
SHIFTS THROUGH TONIGHT. EXPECT ALL RAIN THROUGH THIS EVENING.

AS COOLER WINDS ADVECTS INTO THE AREA FROM THE WSW BEHIND A COLD
FRONT CURRENTLY OVER ERN WI...LAKE ENHANCED/UPSLOPE/SHORTWAVE FORCED
RAIN AND SNOW ALSO BEING FORCED BY A SHORTWAVE WILL RESULT LATE
TONIGHT INTO TUE MORNING. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED
DUE TO WARM GROUND TEMPS AND 2M TEMPS ONLY FALLING INTO THE MID 30S.
SHOWERS WILL TURN TO ALL RAIN AS SFC TEMPS WARM LATE TUE MORNING
INTO TUE AFTERNOON. USED WET BULB ZERO HEIGHTS FROM THE NAM TO
DELINEATE RAIN/SNOW/MIX. HIGHS ON TUE WILL BE IN THE 40S.

&&

.LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 405 PM MON APR 20 2015

THE PATTERN THROUGH THE REST OF THE WEEK WILL BE DOMINATED BY A
MID/UPPER LEVEL LOW MOVING SLOWLY THROUGH THE NORTHERN GREAT LAKES
TOWARD SRN QUEBEC. THIS WILL BRING UNSETTLED WEATHER ALONG WITH
BELOW NORMAL TEMPERATURES.

TUE NIGHT...MODELS SUGGEST THAT A SHORTWAVE TROUGH SLIDING INTO THE
AREA WILL HELP ENHANCE THE PCPN. EXPECT THE HIGHS POPS/COVERAGE FOR
LOCATIONS FAVORED BY UPSLOPE WNW FLOW. WITH DEEP MOISTURE IN PLACE
OVER THE REGION AND 850 MB TEMPS DROPPING FROM AROUND -4C TO
-8C...THERE MAY ALSO BE ENOUGH INSTABILITY FOR SOME LAKE
ENHANCEMENT. WET-BULB ZERO HEIGHTS SUGGEST A TRANSITION FROM RAIN TO
SNOW WILL SPREAD THROUGH THE CWA FROM NW TO SE DURING THE EVENING.
SNOWFALL AMOUNTS TO AROUND AN INCH MAY BE POSSIBLE...MAINLY IN THE
HIGHER TERRAIN. WITH THE TEMPS FALLING OFF TO NEAR 30...SOME WET
SNOW/SLUSH MAY ALSO ACCUMULATE ON SOME ROADS.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN OVER OVER THE
SE CWA DURING PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE
CONTRIBUTION AS 850 MB TEMPS RANGE FROM -9C TO -12C...THE BEST
COVERAGE DURING THE DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM
LAKE SUPERIOR WHERE HEATING WILL BE STRONGEST WITH STEEP SFC-700 MB
LAPSE RATES 700 MB TEMPS TO AROUND -18C WED WILL ONLY MODERATE TO
NEAR -14C THU. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW NORMAL...IN
THE MID 30S TO AROUND 40.

FRI-MON...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH LOW(GFS/GEFS)OR NO(ECMWF) PCPN CHANCES.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 145 PM EDT MON APR 20 2015

EXPECT IMPROVEMENT AT ALL SITES THIS EVENING INTO TONIGHT AS DRIER
AIR MOVES INTO THE AREA. CONDITIONS WILL THEN DETERIORATE TUE
MORNING AS ANOTHER ROUND OF MOISTURE MOVES IN WITH AN UPPER LEVEL
DISTURBANCE. EXACT TIMING AND MAGNITUDE OF DETERIORATING CONDITIONS
ON TUE IS UNCERTAIN AT THIS TIME.

&&

.MARINE...

SW WINDS WILL CONTINUE AS THE SURFACE LOW BEGINS TO PULL NORTH OF
MICHIGAN...SHIFTING THE FOCUS OF THE STRONGEST WINDS AND BIGGEST
WAVES FROM THE LAKE HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...JIT
LONG TERM...JLB
AVIATION...JIT
MARINE...JIT




000
FXUS63 KAPX 202004
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
ISSUED BY NATIONAL WEATHER SERVICE MARQUETTE MI
405 PM EDT MON APR 20 2015

.SHORT TERM...(THROUGH TUESDAY)
ISSUED AT 354 PM EDT MON APR 20 2015

DRIER AIR HAS MOVED INTO THE NERN HALF OF THE CWA THIS AFTERNOON
BEHIND A 983MB SFC LOW JUST E OF LAKE SUPERIOR. LIGHT RAIN AND SNOW
SHOWERS ARE BEING OBSERVED OVER THE FANTASTIC UPPER
PENINSULA...WHILE RAIN SHOWER ARE OCCURING FARTHER SOUTH AND EAST
OVER ERN WI AND WRN LOWER MI. THE WRAP AROUND PRECIP ON THE SW SIDE
OF THE SFC LOW WILL MOVE THROUGH THE CWA THIS EVENING BEFORE DRY AIR
SHIFTS THROUGH TONIGHT. EXPECT ALL RAIN THROUGH THIS EVENING.

AS COOLER WINDS ADVECTS INTO THE AREA FROM THE WSW BEHIND A COLD
FRONT CURRENTLY OVER ERN WI...LAKE ENHANCED/UPSLOPE/SHORTWAVE FORCED
RAIN AND SNOW ALSO BEING FORCED BY A SHORTWAVE WILL RESULT LATE
TONIGHT INTO TUE MORNING. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED
DUE TO WARM GROUND TEMPS AND 2M TEMPS ONLY FALLING INTO THE MID 30S.
SHOWERS WILL TURN TO ALL RAIN AS SFC TEMPS WARM LATE TUE MORNING
INTO TUE AFTERNOON. USED WET BULB ZERO HEIGHTS FROM THE NAM TO
DELINEATE RAIN/SNOW/MIX. HIGHS ON TUE WILL BE IN THE 40S.

&&

.LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 405 PM MON APR 20 2015

THE PATTERN THROUGH THE REST OF THE WEEK WILL BE DOMINATED BY A
MID/UPPER LEVEL LOW MOVING SLOWLY THROUGH THE NORTHERN GREAT LAKES
TOWARD SRN QUEBEC. THIS WILL BRING UNSETTLED WEATHER ALONG WITH
BELOW NORMAL TEMPERATURES.

TUE NIGHT...MODELS SUGGEST THAT A SHORTWAVE TROUGH SLIDING INTO THE
AREA WILL HELP ENHANCE THE PCPN. EXPECT THE HIGHS POPS/COVERAGE FOR
LOCATIONS FAVORED BY UPSLOPE WNW FLOW. WITH DEEP MOISTURE IN PLACE
OVER THE REGION AND 850 MB TEMPS DROPPING FROM AROUND -4C TO
-8C...THERE MAY ALSO BE ENOUGH INSTABILITY FOR SOME LAKE
ENHANCEMENT. WET-BULB ZERO HEIGHTS SUGGEST A TRANSITION FROM RAIN TO
SNOW WILL SPREAD THROUGH THE CWA FROM NW TO SE DURING THE EVENING.
SNOWFALL AMOUNTS TO AROUND AN INCH MAY BE POSSIBLE...MAINLY IN THE
HIGHER TERRAIN. WITH THE TEMPS FALLING OFF TO NEAR 30...SOME WET
SNOW/SLUSH MAY ALSO ACCUMULATE ON SOME ROADS.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN OVER OVER THE
SE CWA DURING PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE
CONTRIBUTION AS 850 MB TEMPS RANGE FROM -9C TO -12C...THE BEST
COVERAGE DURING THE DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM
LAKE SUPERIOR WHERE HEATING WILL BE STRONGEST WITH STEEP SFC-700 MB
LAPSE RATES 700 MB TEMPS TO AROUND -18C WED WILL ONLY MODERATE TO
NEAR -14C THU. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW NORMAL...IN
THE MID 30S TO AROUND 40.

FRI-MON...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH LOW(GFS/GEFS)OR NO(ECMWF) PCPN CHANCES.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 145 PM EDT MON APR 20 2015

EXPECT IMPROVEMENT AT ALL SITES THIS EVENING INTO TONIGHT AS DRIER
AIR MOVES INTO THE AREA. CONDITIONS WILL THEN DETERIORATE TUE
MORNING AS ANOTHER ROUND OF MOISTURE MOVES IN WITH AN UPPER LEVEL
DISTURBANCE. EXACT TIMING AND MAGNITUDE OF DETERIORATING CONDITIONS
ON TUE IS UNCERTAIN AT THIS TIME.

&&

.MARINE...

SW WINDS WILL CONTINUE AS THE SURFACE LOW BEGINS TO PULL NORTH OF
MICHIGAN...SHIFTING THE FOCUS OF THE STRONGEST WINDS AND BIGGEST
WAVES FROM THE LAKE HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...JIT
LONG TERM...JLB
AVIATION...JIT
MARINE...JIT




000
FXUS63 KAPX 202004
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
ISSUED BY NATIONAL WEATHER SERVICE MARQUETTE MI
405 PM EDT MON APR 20 2015

.SHORT TERM...(THROUGH TUESDAY)
ISSUED AT 354 PM EDT MON APR 20 2015

DRIER AIR HAS MOVED INTO THE NERN HALF OF THE CWA THIS AFTERNOON
BEHIND A 983MB SFC LOW JUST E OF LAKE SUPERIOR. LIGHT RAIN AND SNOW
SHOWERS ARE BEING OBSERVED OVER THE FANTASTIC UPPER
PENINSULA...WHILE RAIN SHOWER ARE OCCURING FARTHER SOUTH AND EAST
OVER ERN WI AND WRN LOWER MI. THE WRAP AROUND PRECIP ON THE SW SIDE
OF THE SFC LOW WILL MOVE THROUGH THE CWA THIS EVENING BEFORE DRY AIR
SHIFTS THROUGH TONIGHT. EXPECT ALL RAIN THROUGH THIS EVENING.

AS COOLER WINDS ADVECTS INTO THE AREA FROM THE WSW BEHIND A COLD
FRONT CURRENTLY OVER ERN WI...LAKE ENHANCED/UPSLOPE/SHORTWAVE FORCED
RAIN AND SNOW ALSO BEING FORCED BY A SHORTWAVE WILL RESULT LATE
TONIGHT INTO TUE MORNING. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED
DUE TO WARM GROUND TEMPS AND 2M TEMPS ONLY FALLING INTO THE MID 30S.
SHOWERS WILL TURN TO ALL RAIN AS SFC TEMPS WARM LATE TUE MORNING
INTO TUE AFTERNOON. USED WET BULB ZERO HEIGHTS FROM THE NAM TO
DELINEATE RAIN/SNOW/MIX. HIGHS ON TUE WILL BE IN THE 40S.

&&

.LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 405 PM MON APR 20 2015

THE PATTERN THROUGH THE REST OF THE WEEK WILL BE DOMINATED BY A
MID/UPPER LEVEL LOW MOVING SLOWLY THROUGH THE NORTHERN GREAT LAKES
TOWARD SRN QUEBEC. THIS WILL BRING UNSETTLED WEATHER ALONG WITH
BELOW NORMAL TEMPERATURES.

TUE NIGHT...MODELS SUGGEST THAT A SHORTWAVE TROUGH SLIDING INTO THE
AREA WILL HELP ENHANCE THE PCPN. EXPECT THE HIGHS POPS/COVERAGE FOR
LOCATIONS FAVORED BY UPSLOPE WNW FLOW. WITH DEEP MOISTURE IN PLACE
OVER THE REGION AND 850 MB TEMPS DROPPING FROM AROUND -4C TO
-8C...THERE MAY ALSO BE ENOUGH INSTABILITY FOR SOME LAKE
ENHANCEMENT. WET-BULB ZERO HEIGHTS SUGGEST A TRANSITION FROM RAIN TO
SNOW WILL SPREAD THROUGH THE CWA FROM NW TO SE DURING THE EVENING.
SNOWFALL AMOUNTS TO AROUND AN INCH MAY BE POSSIBLE...MAINLY IN THE
HIGHER TERRAIN. WITH THE TEMPS FALLING OFF TO NEAR 30...SOME WET
SNOW/SLUSH MAY ALSO ACCUMULATE ON SOME ROADS.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN OVER OVER THE
SE CWA DURING PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE
CONTRIBUTION AS 850 MB TEMPS RANGE FROM -9C TO -12C...THE BEST
COVERAGE DURING THE DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM
LAKE SUPERIOR WHERE HEATING WILL BE STRONGEST WITH STEEP SFC-700 MB
LAPSE RATES 700 MB TEMPS TO AROUND -18C WED WILL ONLY MODERATE TO
NEAR -14C THU. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW NORMAL...IN
THE MID 30S TO AROUND 40.

FRI-MON...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH LOW(GFS/GEFS)OR NO(ECMWF) PCPN CHANCES.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 145 PM EDT MON APR 20 2015

EXPECT IMPROVEMENT AT ALL SITES THIS EVENING INTO TONIGHT AS DRIER
AIR MOVES INTO THE AREA. CONDITIONS WILL THEN DETERIORATE TUE
MORNING AS ANOTHER ROUND OF MOISTURE MOVES IN WITH AN UPPER LEVEL
DISTURBANCE. EXACT TIMING AND MAGNITUDE OF DETERIORATING CONDITIONS
ON TUE IS UNCERTAIN AT THIS TIME.

&&

.MARINE...

SW WINDS WILL CONTINUE AS THE SURFACE LOW BEGINS TO PULL NORTH OF
MICHIGAN...SHIFTING THE FOCUS OF THE STRONGEST WINDS AND BIGGEST
WAVES FROM THE LAKE HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...JIT
LONG TERM...JLB
AVIATION...JIT
MARINE...JIT




000
FXUS63 KAPX 202004
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
ISSUED BY NATIONAL WEATHER SERVICE MARQUETTE MI
405 PM EDT MON APR 20 2015

.SHORT TERM...(THROUGH TUESDAY)
ISSUED AT 354 PM EDT MON APR 20 2015

DRIER AIR HAS MOVED INTO THE NERN HALF OF THE CWA THIS AFTERNOON
BEHIND A 983MB SFC LOW JUST E OF LAKE SUPERIOR. LIGHT RAIN AND SNOW
SHOWERS ARE BEING OBSERVED OVER THE FANTASTIC UPPER
PENINSULA...WHILE RAIN SHOWER ARE OCCURING FARTHER SOUTH AND EAST
OVER ERN WI AND WRN LOWER MI. THE WRAP AROUND PRECIP ON THE SW SIDE
OF THE SFC LOW WILL MOVE THROUGH THE CWA THIS EVENING BEFORE DRY AIR
SHIFTS THROUGH TONIGHT. EXPECT ALL RAIN THROUGH THIS EVENING.

AS COOLER WINDS ADVECTS INTO THE AREA FROM THE WSW BEHIND A COLD
FRONT CURRENTLY OVER ERN WI...LAKE ENHANCED/UPSLOPE/SHORTWAVE FORCED
RAIN AND SNOW ALSO BEING FORCED BY A SHORTWAVE WILL RESULT LATE
TONIGHT INTO TUE MORNING. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED
DUE TO WARM GROUND TEMPS AND 2M TEMPS ONLY FALLING INTO THE MID 30S.
SHOWERS WILL TURN TO ALL RAIN AS SFC TEMPS WARM LATE TUE MORNING
INTO TUE AFTERNOON. USED WET BULB ZERO HEIGHTS FROM THE NAM TO
DELINEATE RAIN/SNOW/MIX. HIGHS ON TUE WILL BE IN THE 40S.

&&

.LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 405 PM MON APR 20 2015

THE PATTERN THROUGH THE REST OF THE WEEK WILL BE DOMINATED BY A
MID/UPPER LEVEL LOW MOVING SLOWLY THROUGH THE NORTHERN GREAT LAKES
TOWARD SRN QUEBEC. THIS WILL BRING UNSETTLED WEATHER ALONG WITH
BELOW NORMAL TEMPERATURES.

TUE NIGHT...MODELS SUGGEST THAT A SHORTWAVE TROUGH SLIDING INTO THE
AREA WILL HELP ENHANCE THE PCPN. EXPECT THE HIGHS POPS/COVERAGE FOR
LOCATIONS FAVORED BY UPSLOPE WNW FLOW. WITH DEEP MOISTURE IN PLACE
OVER THE REGION AND 850 MB TEMPS DROPPING FROM AROUND -4C TO
-8C...THERE MAY ALSO BE ENOUGH INSTABILITY FOR SOME LAKE
ENHANCEMENT. WET-BULB ZERO HEIGHTS SUGGEST A TRANSITION FROM RAIN TO
SNOW WILL SPREAD THROUGH THE CWA FROM NW TO SE DURING THE EVENING.
SNOWFALL AMOUNTS TO AROUND AN INCH MAY BE POSSIBLE...MAINLY IN THE
HIGHER TERRAIN. WITH THE TEMPS FALLING OFF TO NEAR 30...SOME WET
SNOW/SLUSH MAY ALSO ACCUMULATE ON SOME ROADS.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN OVER OVER THE
SE CWA DURING PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE
CONTRIBUTION AS 850 MB TEMPS RANGE FROM -9C TO -12C...THE BEST
COVERAGE DURING THE DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM
LAKE SUPERIOR WHERE HEATING WILL BE STRONGEST WITH STEEP SFC-700 MB
LAPSE RATES 700 MB TEMPS TO AROUND -18C WED WILL ONLY MODERATE TO
NEAR -14C THU. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW NORMAL...IN
THE MID 30S TO AROUND 40.

FRI-MON...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH LOW(GFS/GEFS)OR NO(ECMWF) PCPN CHANCES.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 145 PM EDT MON APR 20 2015

EXPECT IMPROVEMENT AT ALL SITES THIS EVENING INTO TONIGHT AS DRIER
AIR MOVES INTO THE AREA. CONDITIONS WILL THEN DETERIORATE TUE
MORNING AS ANOTHER ROUND OF MOISTURE MOVES IN WITH AN UPPER LEVEL
DISTURBANCE. EXACT TIMING AND MAGNITUDE OF DETERIORATING CONDITIONS
ON TUE IS UNCERTAIN AT THIS TIME.

&&

.MARINE...

SW WINDS WILL CONTINUE AS THE SURFACE LOW BEGINS TO PULL NORTH OF
MICHIGAN...SHIFTING THE FOCUS OF THE STRONGEST WINDS AND BIGGEST
WAVES FROM THE LAKE HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...JIT
LONG TERM...JLB
AVIATION...JIT
MARINE...JIT




000
FXUS63 KAPX 202004
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
ISSUED BY NATIONAL WEATHER SERVICE MARQUETTE MI
405 PM EDT MON APR 20 2015

.SHORT TERM...(THROUGH TUESDAY)
ISSUED AT 354 PM EDT MON APR 20 2015

DRIER AIR HAS MOVED INTO THE NERN HALF OF THE CWA THIS AFTERNOON
BEHIND A 983MB SFC LOW JUST E OF LAKE SUPERIOR. LIGHT RAIN AND SNOW
SHOWERS ARE BEING OBSERVED OVER THE FANTASTIC UPPER
PENINSULA...WHILE RAIN SHOWER ARE OCCURING FARTHER SOUTH AND EAST
OVER ERN WI AND WRN LOWER MI. THE WRAP AROUND PRECIP ON THE SW SIDE
OF THE SFC LOW WILL MOVE THROUGH THE CWA THIS EVENING BEFORE DRY AIR
SHIFTS THROUGH TONIGHT. EXPECT ALL RAIN THROUGH THIS EVENING.

AS COOLER WINDS ADVECTS INTO THE AREA FROM THE WSW BEHIND A COLD
FRONT CURRENTLY OVER ERN WI...LAKE ENHANCED/UPSLOPE/SHORTWAVE FORCED
RAIN AND SNOW ALSO BEING FORCED BY A SHORTWAVE WILL RESULT LATE
TONIGHT INTO TUE MORNING. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED
DUE TO WARM GROUND TEMPS AND 2M TEMPS ONLY FALLING INTO THE MID 30S.
SHOWERS WILL TURN TO ALL RAIN AS SFC TEMPS WARM LATE TUE MORNING
INTO TUE AFTERNOON. USED WET BULB ZERO HEIGHTS FROM THE NAM TO
DELINEATE RAIN/SNOW/MIX. HIGHS ON TUE WILL BE IN THE 40S.

&&

.LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 405 PM MON APR 20 2015

THE PATTERN THROUGH THE REST OF THE WEEK WILL BE DOMINATED BY A
MID/UPPER LEVEL LOW MOVING SLOWLY THROUGH THE NORTHERN GREAT LAKES
TOWARD SRN QUEBEC. THIS WILL BRING UNSETTLED WEATHER ALONG WITH
BELOW NORMAL TEMPERATURES.

TUE NIGHT...MODELS SUGGEST THAT A SHORTWAVE TROUGH SLIDING INTO THE
AREA WILL HELP ENHANCE THE PCPN. EXPECT THE HIGHS POPS/COVERAGE FOR
LOCATIONS FAVORED BY UPSLOPE WNW FLOW. WITH DEEP MOISTURE IN PLACE
OVER THE REGION AND 850 MB TEMPS DROPPING FROM AROUND -4C TO
-8C...THERE MAY ALSO BE ENOUGH INSTABILITY FOR SOME LAKE
ENHANCEMENT. WET-BULB ZERO HEIGHTS SUGGEST A TRANSITION FROM RAIN TO
SNOW WILL SPREAD THROUGH THE CWA FROM NW TO SE DURING THE EVENING.
SNOWFALL AMOUNTS TO AROUND AN INCH MAY BE POSSIBLE...MAINLY IN THE
HIGHER TERRAIN. WITH THE TEMPS FALLING OFF TO NEAR 30...SOME WET
SNOW/SLUSH MAY ALSO ACCUMULATE ON SOME ROADS.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN OVER OVER THE
SE CWA DURING PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE
CONTRIBUTION AS 850 MB TEMPS RANGE FROM -9C TO -12C...THE BEST
COVERAGE DURING THE DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM
LAKE SUPERIOR WHERE HEATING WILL BE STRONGEST WITH STEEP SFC-700 MB
LAPSE RATES 700 MB TEMPS TO AROUND -18C WED WILL ONLY MODERATE TO
NEAR -14C THU. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW NORMAL...IN
THE MID 30S TO AROUND 40.

FRI-MON...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH LOW(GFS/GEFS)OR NO(ECMWF) PCPN CHANCES.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 145 PM EDT MON APR 20 2015

EXPECT IMPROVEMENT AT ALL SITES THIS EVENING INTO TONIGHT AS DRIER
AIR MOVES INTO THE AREA. CONDITIONS WILL THEN DETERIORATE TUE
MORNING AS ANOTHER ROUND OF MOISTURE MOVES IN WITH AN UPPER LEVEL
DISTURBANCE. EXACT TIMING AND MAGNITUDE OF DETERIORATING CONDITIONS
ON TUE IS UNCERTAIN AT THIS TIME.

&&

.MARINE...

SW WINDS WILL CONTINUE AS THE SURFACE LOW BEGINS TO PULL NORTH OF
MICHIGAN...SHIFTING THE FOCUS OF THE STRONGEST WINDS AND BIGGEST
WAVES FROM THE LAKE HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...JIT
LONG TERM...JLB
AVIATION...JIT
MARINE...JIT




000
FXUS63 KAPX 202003
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
ISSUED BY NATIONAL WEATHER SERVICE MARQUETTE MI
405 PM EDT MON APR 20 2015

.SHORT TERM...(THROUGH TUESDAY)
ISSUED AT 354 PM EDT MON APR 20 2015

DRIER AIR HAS MOVED INTO THE NERN HALF OF THE CWA THIS AFTERNOON
BEHIND A 983MB SFC LOW JUST E OF LAKE SUPERIOR. LIGHT RAIN AND SNOW
SHOWERS ARE BEING OBSERVED OVER THE FANTASTIC UPPER
PENINSULA...WHILE RAIN SHOWER ARE OCCURING FARTHER SOUTH AND EAST
OVER ERN WI AND WRN LOWER MI. THE WRAP AROUND PRECIP ON THE SW SIDE
OF THE SFC LOW WILL MOVE THROUGH THE CWA THIS EVENING BEFORE DRY AIR
SHIFTS THROUGH TONIGHT. EXPECT ALL RAIN THROUGH THIS EVENING.

AS COOLER WINDS ADVECTS INTO THE AREA FROM THE WSW BEHIND A COLD
FRONT CURRENTLY OVER ERN WI...LAKE ENHANCED/UPSLOPE/SHORTWAVE FORCED
RAIN AND SNOW ALSO BEING FORCED BY A SHORTWAVE WILL RESULT LATE
TONIGHT INTO TUE MORNING. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED
DUE TO WARM GROUND TEMPS AND 2M TEMPS ONLY FALLING INTO THE MID 30S.
SHOWERS WILL TURN TO ALL RAIN AS SFC TEMPS WARM LATE TUE MORNING
INTO TUE AFTERNOON. USED WET BULB ZERO HEIGHTS FROM THE NAM TO
DELINEATE RAIN/SNOW/MIX. HIGHS ON TUE WILL BE IN THE 40S.

&&

.LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 405 PM MON APR 20 2015

THE PATTERN THROUGH THE REST OF THE WEEK WILL BE DOMINATED BY A
MID/UPPER LEVEL LOW MOVING SLOWLY THROUGH THE NORTHERN GREAT LAKES
TOWARD SRN QUEBEC. THIS WILL BRING UNSETTLED WEATHER ALONG WITH
BELOW NORMAL TEMPERATURES.

TUE NIGHT...MODELS SUGGEST THAT A SHORTWAVE TROUGH SLIDING INTO THE
AREA WILL HELP ENHANCE THE PCPN. EXPECT THE HIGHS POPS/COVERAGE FOR
LOCATIONS FAVORED BY UPSLOPE WNW FLOW. WITH DEEP MOISTURE IN PLACE
OVER THE REGION AND 850 MB TEMPS DROPPING FROM AROUND -4C TO
-8C...THERE MAY ALSO BE ENOUGH INSTABILITY FOR SOME LAKE
ENHANCEMENT. WET-BULB ZERO HEIGHTS SUGGEST A TRANSITION FROM RAIN TO
SNOW WILL SPREAD THROUGH THE CWA FROM NW TO SE DURING THE EVENING.
SNOWFALL AMOUNTS TO AROUND AN INCH MAY BE POSSIBLE...MAINLY IN THE
HIGHER TERRAIN. WITH THE TEMPS FALLING OFF TO NEAR 30...SOME WET
SNOW/SLUSH MAY ALSO ACCUMULATE ON SOME ROADS.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN OVER OVER THE
SE CWA DURING PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE
CONTRIBUTION AS 850 MB TEMPS RANGE FROM -9C TO -12C...THE BEST
COVERAGE DURING THE DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM
LAKE SUPERIOR WHERE HEATING WILL BE STRONGEST WITH STEEP SFC-700 MB
LAPSE RATES 700 MB TEMPS TO AROUND -18C WED WILL ONLY MODERATE TO
NEAR -14C THU. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW NORMAL...IN
THE MID 30S TO AROUND 40.

FRI-MON...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH LOW(GFS/GEFS)OR NO(ECMWF) PCPN CHANCES.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 145 PM EDT MON APR 20 2015

EXPECT IMPROVEMENT AT ALL SITES THIS EVENING INTO TONIGHT AS DRIER
AIR MOVES INTO THE AREA. CONDITIONS WILL THEN DETERIORATE TUE
MORNING AS ANOTHER ROUND OF MOISTURE MOVES IN WITH AN UPPER LEVEL
DISTURBANCE. EXACT TIMING AND MAGNITUDE OF DETERIORATING CONDITIONS
ON TUE IS UNCERTAIN AT THIS TIME.

&&

.MARINE...

SW WINDS WILL CONTINUE AS THE SURFACE LOW BEGINS TO PULL NORTH OF
MICHIGAN...SHIFTING THE FOCUS OF THE STRONGEST WINDS AND BIGGEST
WAVES FROM THE LAKE HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...JIT
LONG TERM...JLB
AVIATION...JIT
MARINE...JIT



000
FXUS63 KAPX 202003
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
ISSUED BY NATIONAL WEATHER SERVICE MARQUETTE MI
405 PM EDT MON APR 20 2015

.SHORT TERM...(THROUGH TUESDAY)
ISSUED AT 354 PM EDT MON APR 20 2015

DRIER AIR HAS MOVED INTO THE NERN HALF OF THE CWA THIS AFTERNOON
BEHIND A 983MB SFC LOW JUST E OF LAKE SUPERIOR. LIGHT RAIN AND SNOW
SHOWERS ARE BEING OBSERVED OVER THE FANTASTIC UPPER
PENINSULA...WHILE RAIN SHOWER ARE OCCURING FARTHER SOUTH AND EAST
OVER ERN WI AND WRN LOWER MI. THE WRAP AROUND PRECIP ON THE SW SIDE
OF THE SFC LOW WILL MOVE THROUGH THE CWA THIS EVENING BEFORE DRY AIR
SHIFTS THROUGH TONIGHT. EXPECT ALL RAIN THROUGH THIS EVENING.

AS COOLER WINDS ADVECTS INTO THE AREA FROM THE WSW BEHIND A COLD
FRONT CURRENTLY OVER ERN WI...LAKE ENHANCED/UPSLOPE/SHORTWAVE FORCED
RAIN AND SNOW ALSO BEING FORCED BY A SHORTWAVE WILL RESULT LATE
TONIGHT INTO TUE MORNING. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED
DUE TO WARM GROUND TEMPS AND 2M TEMPS ONLY FALLING INTO THE MID 30S.
SHOWERS WILL TURN TO ALL RAIN AS SFC TEMPS WARM LATE TUE MORNING
INTO TUE AFTERNOON. USED WET BULB ZERO HEIGHTS FROM THE NAM TO
DELINEATE RAIN/SNOW/MIX. HIGHS ON TUE WILL BE IN THE 40S.

&&

.LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 405 PM MON APR 20 2015

THE PATTERN THROUGH THE REST OF THE WEEK WILL BE DOMINATED BY A
MID/UPPER LEVEL LOW MOVING SLOWLY THROUGH THE NORTHERN GREAT LAKES
TOWARD SRN QUEBEC. THIS WILL BRING UNSETTLED WEATHER ALONG WITH
BELOW NORMAL TEMPERATURES.

TUE NIGHT...MODELS SUGGEST THAT A SHORTWAVE TROUGH SLIDING INTO THE
AREA WILL HELP ENHANCE THE PCPN. EXPECT THE HIGHS POPS/COVERAGE FOR
LOCATIONS FAVORED BY UPSLOPE WNW FLOW. WITH DEEP MOISTURE IN PLACE
OVER THE REGION AND 850 MB TEMPS DROPPING FROM AROUND -4C TO
-8C...THERE MAY ALSO BE ENOUGH INSTABILITY FOR SOME LAKE
ENHANCEMENT. WET-BULB ZERO HEIGHTS SUGGEST A TRANSITION FROM RAIN TO
SNOW WILL SPREAD THROUGH THE CWA FROM NW TO SE DURING THE EVENING.
SNOWFALL AMOUNTS TO AROUND AN INCH MAY BE POSSIBLE...MAINLY IN THE
HIGHER TERRAIN. WITH THE TEMPS FALLING OFF TO NEAR 30...SOME WET
SNOW/SLUSH MAY ALSO ACCUMULATE ON SOME ROADS.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN OVER OVER THE
SE CWA DURING PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE
CONTRIBUTION AS 850 MB TEMPS RANGE FROM -9C TO -12C...THE BEST
COVERAGE DURING THE DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM
LAKE SUPERIOR WHERE HEATING WILL BE STRONGEST WITH STEEP SFC-700 MB
LAPSE RATES 700 MB TEMPS TO AROUND -18C WED WILL ONLY MODERATE TO
NEAR -14C THU. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW NORMAL...IN
THE MID 30S TO AROUND 40.

FRI-MON...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH LOW(GFS/GEFS)OR NO(ECMWF) PCPN CHANCES.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 145 PM EDT MON APR 20 2015

EXPECT IMPROVEMENT AT ALL SITES THIS EVENING INTO TONIGHT AS DRIER
AIR MOVES INTO THE AREA. CONDITIONS WILL THEN DETERIORATE TUE
MORNING AS ANOTHER ROUND OF MOISTURE MOVES IN WITH AN UPPER LEVEL
DISTURBANCE. EXACT TIMING AND MAGNITUDE OF DETERIORATING CONDITIONS
ON TUE IS UNCERTAIN AT THIS TIME.

&&

.MARINE...

SW WINDS WILL CONTINUE AS THE SURFACE LOW BEGINS TO PULL NORTH OF
MICHIGAN...SHIFTING THE FOCUS OF THE STRONGEST WINDS AND BIGGEST
WAVES FROM THE LAKE HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...JIT
LONG TERM...JLB
AVIATION...JIT
MARINE...JIT




000
FXUS63 KAPX 202003
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
ISSUED BY NATIONAL WEATHER SERVICE MARQUETTE MI
405 PM EDT MON APR 20 2015

.SHORT TERM...(THROUGH TUESDAY)
ISSUED AT 354 PM EDT MON APR 20 2015

DRIER AIR HAS MOVED INTO THE NERN HALF OF THE CWA THIS AFTERNOON
BEHIND A 983MB SFC LOW JUST E OF LAKE SUPERIOR. LIGHT RAIN AND SNOW
SHOWERS ARE BEING OBSERVED OVER THE FANTASTIC UPPER
PENINSULA...WHILE RAIN SHOWER ARE OCCURING FARTHER SOUTH AND EAST
OVER ERN WI AND WRN LOWER MI. THE WRAP AROUND PRECIP ON THE SW SIDE
OF THE SFC LOW WILL MOVE THROUGH THE CWA THIS EVENING BEFORE DRY AIR
SHIFTS THROUGH TONIGHT. EXPECT ALL RAIN THROUGH THIS EVENING.

AS COOLER WINDS ADVECTS INTO THE AREA FROM THE WSW BEHIND A COLD
FRONT CURRENTLY OVER ERN WI...LAKE ENHANCED/UPSLOPE/SHORTWAVE FORCED
RAIN AND SNOW ALSO BEING FORCED BY A SHORTWAVE WILL RESULT LATE
TONIGHT INTO TUE MORNING. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED
DUE TO WARM GROUND TEMPS AND 2M TEMPS ONLY FALLING INTO THE MID 30S.
SHOWERS WILL TURN TO ALL RAIN AS SFC TEMPS WARM LATE TUE MORNING
INTO TUE AFTERNOON. USED WET BULB ZERO HEIGHTS FROM THE NAM TO
DELINEATE RAIN/SNOW/MIX. HIGHS ON TUE WILL BE IN THE 40S.

&&

.LONG TERM...(FRIDAY THROUGH MONDAY) ISSUED AT 405 PM MON APR 20 2015

THE PATTERN THROUGH THE REST OF THE WEEK WILL BE DOMINATED BY A
MID/UPPER LEVEL LOW MOVING SLOWLY THROUGH THE NORTHERN GREAT LAKES
TOWARD SRN QUEBEC. THIS WILL BRING UNSETTLED WEATHER ALONG WITH
BELOW NORMAL TEMPERATURES.

TUE NIGHT...MODELS SUGGEST THAT A SHORTWAVE TROUGH SLIDING INTO THE
AREA WILL HELP ENHANCE THE PCPN. EXPECT THE HIGHS POPS/COVERAGE FOR
LOCATIONS FAVORED BY UPSLOPE WNW FLOW. WITH DEEP MOISTURE IN PLACE
OVER THE REGION AND 850 MB TEMPS DROPPING FROM AROUND -4C TO
-8C...THERE MAY ALSO BE ENOUGH INSTABILITY FOR SOME LAKE
ENHANCEMENT. WET-BULB ZERO HEIGHTS SUGGEST A TRANSITION FROM RAIN TO
SNOW WILL SPREAD THROUGH THE CWA FROM NW TO SE DURING THE EVENING.
SNOWFALL AMOUNTS TO AROUND AN INCH MAY BE POSSIBLE...MAINLY IN THE
HIGHER TERRAIN. WITH THE TEMPS FALLING OFF TO NEAR 30...SOME WET
SNOW/SLUSH MAY ALSO ACCUMULATE ON SOME ROADS.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN OVER OVER THE
SE CWA DURING PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE
CONTRIBUTION AS 850 MB TEMPS RANGE FROM -9C TO -12C...THE BEST
COVERAGE DURING THE DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM
LAKE SUPERIOR WHERE HEATING WILL BE STRONGEST WITH STEEP SFC-700 MB
LAPSE RATES 700 MB TEMPS TO AROUND -18C WED WILL ONLY MODERATE TO
NEAR -14C THU. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW NORMAL...IN
THE MID 30S TO AROUND 40.

FRI-MON...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH LOW(GFS/GEFS)OR NO(ECMWF) PCPN CHANCES.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 145 PM EDT MON APR 20 2015

EXPECT IMPROVEMENT AT ALL SITES THIS EVENING INTO TONIGHT AS DRIER
AIR MOVES INTO THE AREA. CONDITIONS WILL THEN DETERIORATE TUE
MORNING AS ANOTHER ROUND OF MOISTURE MOVES IN WITH AN UPPER LEVEL
DISTURBANCE. EXACT TIMING AND MAGNITUDE OF DETERIORATING CONDITIONS
ON TUE IS UNCERTAIN AT THIS TIME.

&&

.MARINE...

SW WINDS WILL CONTINUE AS THE SURFACE LOW BEGINS TO PULL NORTH OF
MICHIGAN...SHIFTING THE FOCUS OF THE STRONGEST WINDS AND BIGGEST
WAVES FROM THE LAKE HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...JIT
LONG TERM...JLB
AVIATION...JIT
MARINE...JIT




000
FXUS63 KAPX 201956
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
ISSUED BY NATIONAL WEATHER SERVICE MARQUETTE MI
356 PM EDT MON APR 20 2015

.SHORT TERM...(THROUGH TUESDAY)
ISSUED AT 354 PM EDT MON APR 20 2015

DRIER AIR HAS MOVED INTO THE NERN HALF OF THE CWA THIS AFTERNOON
BEHIND A 983MB SFC LOW JUST E OF LAKE SUPERIOR. LIGHT RAIN AND SNOW
SHOWERS ARE BEING OBSERVED OVER THE FANTASTIC UPPER
PENINSULA...WHILE RAIN SHOWER ARE OCCURING FARTHER SOUTH AND EAST
OVER ERN WI AND WRN LOWER MI. THE WRAP AROUND PRECIP ON THE SW SIDE
OF THE SFC LOW WILL MOVE THROUGH THE CWA THIS EVENING BEFORE DRY AIR
SHIFTS THROUGH TONIGHT. EXPECT ALL RAIN THROUGH THIS EVENING.

AS COOLER WINDS ADVECTS INTO THE AREA FROM THE WSW BEHIND A COLD
FRONT CURRENTLY OVER ERN WI...LAKE ENHANCED/UPSLOPE/SHORTWAVE FORCED
RAIN AND SNOW ALSO BEING FORCED BY A SHORTWAVE WILL RESULT LATE
TONIGHT INTO TUE MORNING. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED
DUE TO WARM GROUND TEMPS AND 2M TEMPS ONLY FALLING INTO THE MID 30S.
SHOWERS WILL TURN TO ALL RAIN AS SFC TEMPS WARM LATE TUE MORNING
INTO TUE AFTERNOON. USED WET BULB ZERO HEIGHTS FROM THE NAM TO
DELINEATE RAIN/SNOW/MIX. HIGHS ON TUE WILL BE IN THE 40S.

&&

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 245 AM EDT MON APR 20 2015

STILL SOME DISCREPANCIES
REGARDING JUST HOW LONG THIS SYSTEM LINGERS INTO THE END OF THE
WEEK...WITH THE GFS/GEFS/GEM NOTABLY SLOWER MOVING IT OUT THAN
RECENT ECMWF/UKMET RUNS. GIVEN UNCERTAINTIES...WILL SIMPLY RIDE WITH
INHERITED FORECAST...FEATURING SOME LINGERING LIGHT RAIN/SNOW
SHOWERS (AT LEAST FOR PARTS OF THE AREA) RIGHT THROUGH
FRIDAY...GIVING WAY TO A DRY WEEKEND. NO MATTER HOW FAST THIS SYSTEM
EXITS...AIRMASS RECOVERY WILL BE A SLOW ONE...SUGGESTING
TEMPERATURES REMAINING BELOW NORMAL RIGHT THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 145 PM EDT MON APR 20 2015

EXPECT IMPROVEMENT AT ALL SITES THIS EVENING INTO TONIGHT AS DRIER
AIR MOVES INTO THE AREA. CONDITIONS WILL THEN DETERIORATE TUE
MORNING AS ANOTHER ROUND OF MOISTURE MOVES IN WITH AN UPPER LEVEL
DISTURBANCE. EXACT TIMING AND MAGNITUDE OF DETERIORATING CONDITIONS
ON TUE IS UNCERTAIN AT THIS TIME.

&&

.MARINE...

SW WINDS WILL CONTINUE AS THE SURFACE LOW BEGINS TO PULL NORTH OF
MICHIGAN...SHIFTING THE FOCUS OF THE STRONGEST WINDS AND BIGGEST
WAVES FROM THE LAKE HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...JIT
LONG TERM...MSB
AVIATION...JIT
MARINE...JIT



000
FXUS63 KAPX 201956
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
ISSUED BY NATIONAL WEATHER SERVICE MARQUETTE MI
356 PM EDT MON APR 20 2015

.SHORT TERM...(THROUGH TUESDAY)
ISSUED AT 354 PM EDT MON APR 20 2015

DRIER AIR HAS MOVED INTO THE NERN HALF OF THE CWA THIS AFTERNOON
BEHIND A 983MB SFC LOW JUST E OF LAKE SUPERIOR. LIGHT RAIN AND SNOW
SHOWERS ARE BEING OBSERVED OVER THE FANTASTIC UPPER
PENINSULA...WHILE RAIN SHOWER ARE OCCURING FARTHER SOUTH AND EAST
OVER ERN WI AND WRN LOWER MI. THE WRAP AROUND PRECIP ON THE SW SIDE
OF THE SFC LOW WILL MOVE THROUGH THE CWA THIS EVENING BEFORE DRY AIR
SHIFTS THROUGH TONIGHT. EXPECT ALL RAIN THROUGH THIS EVENING.

AS COOLER WINDS ADVECTS INTO THE AREA FROM THE WSW BEHIND A COLD
FRONT CURRENTLY OVER ERN WI...LAKE ENHANCED/UPSLOPE/SHORTWAVE FORCED
RAIN AND SNOW ALSO BEING FORCED BY A SHORTWAVE WILL RESULT LATE
TONIGHT INTO TUE MORNING. NO SIGNIFICANT ACCUMULATIONS ARE EXPECTED
DUE TO WARM GROUND TEMPS AND 2M TEMPS ONLY FALLING INTO THE MID 30S.
SHOWERS WILL TURN TO ALL RAIN AS SFC TEMPS WARM LATE TUE MORNING
INTO TUE AFTERNOON. USED WET BULB ZERO HEIGHTS FROM THE NAM TO
DELINEATE RAIN/SNOW/MIX. HIGHS ON TUE WILL BE IN THE 40S.

&&

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 245 AM EDT MON APR 20 2015

STILL SOME DISCREPANCIES
REGARDING JUST HOW LONG THIS SYSTEM LINGERS INTO THE END OF THE
WEEK...WITH THE GFS/GEFS/GEM NOTABLY SLOWER MOVING IT OUT THAN
RECENT ECMWF/UKMET RUNS. GIVEN UNCERTAINTIES...WILL SIMPLY RIDE WITH
INHERITED FORECAST...FEATURING SOME LINGERING LIGHT RAIN/SNOW
SHOWERS (AT LEAST FOR PARTS OF THE AREA) RIGHT THROUGH
FRIDAY...GIVING WAY TO A DRY WEEKEND. NO MATTER HOW FAST THIS SYSTEM
EXITS...AIRMASS RECOVERY WILL BE A SLOW ONE...SUGGESTING
TEMPERATURES REMAINING BELOW NORMAL RIGHT THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 145 PM EDT MON APR 20 2015

EXPECT IMPROVEMENT AT ALL SITES THIS EVENING INTO TONIGHT AS DRIER
AIR MOVES INTO THE AREA. CONDITIONS WILL THEN DETERIORATE TUE
MORNING AS ANOTHER ROUND OF MOISTURE MOVES IN WITH AN UPPER LEVEL
DISTURBANCE. EXACT TIMING AND MAGNITUDE OF DETERIORATING CONDITIONS
ON TUE IS UNCERTAIN AT THIS TIME.

&&

.MARINE...

SW WINDS WILL CONTINUE AS THE SURFACE LOW BEGINS TO PULL NORTH OF
MICHIGAN...SHIFTING THE FOCUS OF THE STRONGEST WINDS AND BIGGEST
WAVES FROM THE LAKE HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

SHORT TERM...JIT
LONG TERM...MSB
AVIATION...JIT
MARINE...JIT




000
FXUS63 KMQT 201953
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
353 PM EDT MON APR 20 2015

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 353 PM EDT MON APR 20 2015

12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEPENING UPR TROF
OVER CENTRAL NAMERICA BTWN RDGS ALONG THE E AND W COASTS...WITH 12HR
H5 HGT FALLS UP TO 150M NOTED OVER NRN WI IN ADVANCE OF SHRTWV
LIFTING NWD INTO THE UPR LKS TO THE E OF THE UPR TROF AXIS. IR AND
WV IMAGERY SHOW A WELL DEFINED COMMA HEAD CLD OVER THE UPR GREAT LKS
IN ADVANCE OF SHRTWV AND ON CYC SIDE OF ACCOMPANYING H7 LO TRACK.
STEADY RA UNDER THIS COMMA HEAD HAS MIXED WITH SN OVER THE WRN CWA
WHERE DYNAMIC COOLING AND SOME LLVL CAA HAVE COOLED THE COLUMN
SUFFICIENTLY. FARTHER TO THE E...DRY SLOTTING ON THE ACYC SIDE OF H7
LO TRACK HAS TENDED TO DIMINISH THE PCPN COVERAGE/INTENSITY OVER THE
FAR E. ANOTHER SHRTWV IS DIGGING SWD THRU FAR NW ONTARIO/MANITOBA ON
THE WRN FLANK OF H5 CLOSED LO

MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/PTYPE ASSOCIATED
WITH SHRTWV MOVING THRU THE UPR LKS RIGHT NOW AND THEN TNGT/TMRW
ACCOMPANYING PASSAGE OF NEXT SHRTWV AND WITHIN LINGERING DEEP CYC
FLOW UNDER CUTOFF H5 LO PROGGED TO LINGER OVER THE UPR LKS.

LATE TDAY/TNGT...AS SHRTWV E OF THE UPR TROF AXIS LIFTS TO THE N
THRU THIS AFTN AND TENDS TO SHEAR OUT...MODELS SHOW AREA OF SHARP
DEEP LYR QVECTOR CNVGC SUPPORTING AXIS OF COLDER CLD TOPS
DIMINISHING AND GIVING WAY TO SOME DEEP LYR QVECTOR DVGC. SO AREA OF
STEADY RA/SN OVER THE W SHOULD DIMINISH BY LATE AFTN WITH ARRIVAL OF
THE NEGATIVE DYNAMICS/MID LVL DRYING. POPS OVER THE E WL TEND TO
INCREASE LATE THIS AFTN/EARLY EVNG AS COMMA TAIL AXIS OF HIER RH
SWINGS E THRU THAT AREA...BUT PCPN INTENSITY WL NOT BE AS GREAT AS
OVER THE W SINCE THE SUPPORTING AXIS OF DIMINISHING DEEP LYR QVECTOR
CNVGC IS FCST TO REMAIN OVER THE W. NOT OUT OF THE QUESTION THERE
COULD BE A FEW INCHES OF WET SN ACCUM OVER THE HIER TERRAIN OF THE
W...BUT THERE SHOULD BE LTL IF ANY SN OVER THE E HALF WITH WEAKER
DYNAMIC FORCING/COOLING. LATER TNGT...THE TRAILING SHRTWV DIGGING
SWD TOWARD NW MN ON THE WRN FLANK OF CLOSED H5 LO IS FCST TO DIG TO
NEAR NW WI BY 12Z TUE...BRINGING SOME DPVA/MORE DEEP LYR QVECTOR
CNVGC TO THE W LATER TNGT. SHARP CYC UPSLOPE WNW FLOW IN THE
PRESENCE OF THE DEEPER FORCING/MSTR WL SUPPORT LIKELY POPS IN THIS
AREA. THERE COULD BE A FEW INCHES OF WET SN ACCUM OVER MAINLY THE
HIER TERRAIN. OVER THE CENTRAL AND E...THERE WL BE ONLY ISOLD-SCT RA
AND SN SHOWERS.

TUE...SHRTWV/ACCOMPANYING SFC LO PRES TROF ROTATING ARND CLOSED H5
LO SHIFTING SLOWLY TO THE E OVER LK SUP IS FCST TO WEAKEN SLOWLY...
LEADING TO SLOWLY DIMINISHING DEEP LYR QVECTOR CNVGC. ALTHOUGH THESE
TRENDS WL RESULT IN DIMINISHING POPS...DAYTIME HEATING/LLVL
DESTABILIZATION WL ENHANCE POPS ESPECIALLY OVER THE ERN CWA IN THE
AFTN...WHERE LLVL CNVGC WITHIN LO PRES TROF WL BE ENHANCED BY LK
BREEZE DEVELOPMENT. OTRW...LINGERING SHARP LLVL CNVGC AND THE
DAYTIME HEATING WL MAINTAIN AT LEAST CHC POPS. THE PCPN SHOULD BE
MAINLY SN IN THE MRNG...BUT THIS PCPN WL MIX WITH/CHG TO RA OVER THE
SE HALF IN THE AFTN WITH DAYTIME HEATING/TEMPS RISING AOA 40.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 PM EDT MON APR 20 2015

A LARGE UPPER LOW CENTERED OVER NORTHERN ONTARIO WILL BE
INFLUENCING THE GREAT LAKES REGION THROUGH THE FIRST HALF OF THE
LONG TERM PERIOD. THIS WILL LEAD TO BELOW NORMAL TEMPERATURES AND
PERIODS OF SNOW BEFORE GRADUALLY SHIFTING EAST INTO THE ATLANTIC BY
THE WEEKEND.

AS THAT UPPER LOW SPINS BETWEEN LAKE SUPERIOR AND JAMES BAY...IT
WILL ROTATE SEVERAL SHORTWAVES ACROSS THE UPPER GREAT LAKES REGION
TUESDAY NIGHT THROUGH THURSDAY. THESE WAVES WILL BRING PERIODS OF
SHOWERS TO THE AREA...WITH HELP FROM BOTH LAKE SUPERIOR (850MB
TEMPS FALLING TO -10C TO -12C ON WEDNESDAY MORNING) AND TERRAIN
ENHANCEMENT (PERSISTENT LOW LEVEL NORTHWESTERLY FLOW). WILL CONTINUE
TO FOCUS THE HIGHEST POPS (LIKELY VALUES) IN THOSE AREAS FAVORED BY
ALL THREE FEATURES (HIGHER TERRAIN OF THE WEST/NORTHWEST) AND ALSO
EAST DOWNWIND OF LAKE SUPERIOR...AND INCLUDE CHANCE/SLIGHTS FOR THE
REST OF THE CWA. WITH THE AMOUNT OF COLD AIR IN PLACE...EXPECT THE
PRECIPITATION TO FALL MAINLY AS SNOW. WITH LOW LEVEL TEMPERATURES
WARMING AWAY OVER THE SOUTHERN THIRD OF THE CWA...COULD SEE SOME
RAIN MIXING IN THERE...BUT OTHERWISE SNOW WILL BE THE NORM. COULD
SEE A COUPLE INCHES OF ACCUMULATION IN THE FAVORED LOCATIONS
TUESDAY NIGHT AND UP TO AN INCH WEDNESDAY AND AGAIN WEDNESDAY
NIGHT. WITH DRIER AIR STARTING TO MOVE INTO THE AREA ON
THURSDAY (ASSOCIATED WITH A SURFACE RIDGE MOVING INTO THE
NORTHERN PLAINS...SHOULD SEE THE COVERAGE OF THE SHOWERS
DIMINISHING THROUGH THE DAY THURSDAY AND CONTINUING TO WEAKENING
INTO FRIDAY. ALSO...DON/T EXPECT HIGHS TO RISE MUCH OUT OF THE
LOW-MID 30S ON WED/THURS OVER THE NORTH HALF OF THE CWA...WITH SOME
HIGHS AROUND 40 OVER THE SOUTH CENTRAL. WILL LIKELY BREAK THE
RECORD LOW HIGH TEMPERATURE HERE AT OUR OFFICE ON WEDNESDAY (36 SET
IN 1972).

EXTENDED RANGE MODELS DIFFER ON HOW QUICKLY THE UPPER LOW DEPARTS
THIS WEEKEND...BUT SHOULD STILL SEE ENOUGH INFLUENCE FROM THE
SURFACE RIDGE MOVING INTO THE NORTHERN PLAINS TO KEEP MOST OF THE
AREA DRY. WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR...EXPECT
TEMPERATURES TO REMAIN BELOW NORMAL BUT IN THE 40S TO AROUND 50. AS
THE UPPER LOW RETROGRADES BACK OVER QUEBEC EARLY NEXT WEEK...COULD
SEE THE UPPER GREAT LAKES REGION BEING AFFECTED BY THE WESTERN EDGE
OF THE ENERGY ROTATING AROUND THE UPPER LOW AND LIKELY KEEPING
BELOW NORMAL TEMPERATURES IN PLACE THROUGH THE END OF APRIL.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 131 PM EDT MON APR 20 2015

AREA OF DEEPER MSTR ASSOCIATED WITH BAND OF SHARPER FORCING WL BRING
A PERIOD OF STEADY SN TO CMX THRU THIS AFTN ALONG WITH LIFR
CONDITIONS. GUSTY W WINDS TO NEAR 30 KTS WL ALSO IMPACT THIS MORE
EXPOSED LOCATION. THE AREA OF PCPN WL EXIT IWD SOON AFTER TAF
ISSUANCE...SO EXPECT AN IMPROVEMENT THERE FM IFR TO MVFR WITH THE
ARRIVAL OF SOME DRIER AIR/SUBSIDENCE. SINCE THE BAND OF HEAVIER PCPN
IS LIKELY TO REMAIN TO THE W OF SAW...THERE SHOULD BE MVFR CIGS WITH
ONLY SOME OCNL -SHRA IN THE PRESENCE OF A DOWNSLOPE WIND COMPONENT.
FOR THIS EVNG...MVFR CONDITIONS SHOULD BE THE RULE WITH MVFR CIGS
AND ONLY SOME SCT LIGHT -SHSN OR -SHSNRA. BUT THE APRCH OF ANOTHER
DISTURBANCE/LO PRES TROF LATE TNGT SHOULD RESULT IN DETERIORATING
CONDITIONS AGAIN WITH IFR CONDITIONS DVLPG AT IWD AND CMX. DOWNSLOPE
WINDS AT SAW WL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO IWD AND CMX BY LATE MRNG ON TUE.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 353 PM EDT MON APR 20 2015

SHARP PRES GRADIENT ON THE SW FLANK OF SLOW MOVING LO PRES IN
ONTARIO WILL CAUSE W TO NW WINDS UP TO 25-30 KTS INTO THU. ALTHOUGH
THERE COULD BE SOME GALE FORCE GUSTS AT TIMES...WIDESPREAD GALES ARE
NOT EXPECTED. THE CLOSER APPROACH OF HI PRES LATER IN THE WEEK WILL
RESULT IN NW WINDS DIMINISHING TO NO MORE THAN 20 KTS ON FRI AND
SAT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC



000
FXUS63 KMQT 201953
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
353 PM EDT MON APR 20 2015

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 353 PM EDT MON APR 20 2015

12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEPENING UPR TROF
OVER CENTRAL NAMERICA BTWN RDGS ALONG THE E AND W COASTS...WITH 12HR
H5 HGT FALLS UP TO 150M NOTED OVER NRN WI IN ADVANCE OF SHRTWV
LIFTING NWD INTO THE UPR LKS TO THE E OF THE UPR TROF AXIS. IR AND
WV IMAGERY SHOW A WELL DEFINED COMMA HEAD CLD OVER THE UPR GREAT LKS
IN ADVANCE OF SHRTWV AND ON CYC SIDE OF ACCOMPANYING H7 LO TRACK.
STEADY RA UNDER THIS COMMA HEAD HAS MIXED WITH SN OVER THE WRN CWA
WHERE DYNAMIC COOLING AND SOME LLVL CAA HAVE COOLED THE COLUMN
SUFFICIENTLY. FARTHER TO THE E...DRY SLOTTING ON THE ACYC SIDE OF H7
LO TRACK HAS TENDED TO DIMINISH THE PCPN COVERAGE/INTENSITY OVER THE
FAR E. ANOTHER SHRTWV IS DIGGING SWD THRU FAR NW ONTARIO/MANITOBA ON
THE WRN FLANK OF H5 CLOSED LO

MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/PTYPE ASSOCIATED
WITH SHRTWV MOVING THRU THE UPR LKS RIGHT NOW AND THEN TNGT/TMRW
ACCOMPANYING PASSAGE OF NEXT SHRTWV AND WITHIN LINGERING DEEP CYC
FLOW UNDER CUTOFF H5 LO PROGGED TO LINGER OVER THE UPR LKS.

LATE TDAY/TNGT...AS SHRTWV E OF THE UPR TROF AXIS LIFTS TO THE N
THRU THIS AFTN AND TENDS TO SHEAR OUT...MODELS SHOW AREA OF SHARP
DEEP LYR QVECTOR CNVGC SUPPORTING AXIS OF COLDER CLD TOPS
DIMINISHING AND GIVING WAY TO SOME DEEP LYR QVECTOR DVGC. SO AREA OF
STEADY RA/SN OVER THE W SHOULD DIMINISH BY LATE AFTN WITH ARRIVAL OF
THE NEGATIVE DYNAMICS/MID LVL DRYING. POPS OVER THE E WL TEND TO
INCREASE LATE THIS AFTN/EARLY EVNG AS COMMA TAIL AXIS OF HIER RH
SWINGS E THRU THAT AREA...BUT PCPN INTENSITY WL NOT BE AS GREAT AS
OVER THE W SINCE THE SUPPORTING AXIS OF DIMINISHING DEEP LYR QVECTOR
CNVGC IS FCST TO REMAIN OVER THE W. NOT OUT OF THE QUESTION THERE
COULD BE A FEW INCHES OF WET SN ACCUM OVER THE HIER TERRAIN OF THE
W...BUT THERE SHOULD BE LTL IF ANY SN OVER THE E HALF WITH WEAKER
DYNAMIC FORCING/COOLING. LATER TNGT...THE TRAILING SHRTWV DIGGING
SWD TOWARD NW MN ON THE WRN FLANK OF CLOSED H5 LO IS FCST TO DIG TO
NEAR NW WI BY 12Z TUE...BRINGING SOME DPVA/MORE DEEP LYR QVECTOR
CNVGC TO THE W LATER TNGT. SHARP CYC UPSLOPE WNW FLOW IN THE
PRESENCE OF THE DEEPER FORCING/MSTR WL SUPPORT LIKELY POPS IN THIS
AREA. THERE COULD BE A FEW INCHES OF WET SN ACCUM OVER MAINLY THE
HIER TERRAIN. OVER THE CENTRAL AND E...THERE WL BE ONLY ISOLD-SCT RA
AND SN SHOWERS.

TUE...SHRTWV/ACCOMPANYING SFC LO PRES TROF ROTATING ARND CLOSED H5
LO SHIFTING SLOWLY TO THE E OVER LK SUP IS FCST TO WEAKEN SLOWLY...
LEADING TO SLOWLY DIMINISHING DEEP LYR QVECTOR CNVGC. ALTHOUGH THESE
TRENDS WL RESULT IN DIMINISHING POPS...DAYTIME HEATING/LLVL
DESTABILIZATION WL ENHANCE POPS ESPECIALLY OVER THE ERN CWA IN THE
AFTN...WHERE LLVL CNVGC WITHIN LO PRES TROF WL BE ENHANCED BY LK
BREEZE DEVELOPMENT. OTRW...LINGERING SHARP LLVL CNVGC AND THE
DAYTIME HEATING WL MAINTAIN AT LEAST CHC POPS. THE PCPN SHOULD BE
MAINLY SN IN THE MRNG...BUT THIS PCPN WL MIX WITH/CHG TO RA OVER THE
SE HALF IN THE AFTN WITH DAYTIME HEATING/TEMPS RISING AOA 40.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 PM EDT MON APR 20 2015

A LARGE UPPER LOW CENTERED OVER NORTHERN ONTARIO WILL BE
INFLUENCING THE GREAT LAKES REGION THROUGH THE FIRST HALF OF THE
LONG TERM PERIOD. THIS WILL LEAD TO BELOW NORMAL TEMPERATURES AND
PERIODS OF SNOW BEFORE GRADUALLY SHIFTING EAST INTO THE ATLANTIC BY
THE WEEKEND.

AS THAT UPPER LOW SPINS BETWEEN LAKE SUPERIOR AND JAMES BAY...IT
WILL ROTATE SEVERAL SHORTWAVES ACROSS THE UPPER GREAT LAKES REGION
TUESDAY NIGHT THROUGH THURSDAY. THESE WAVES WILL BRING PERIODS OF
SHOWERS TO THE AREA...WITH HELP FROM BOTH LAKE SUPERIOR (850MB
TEMPS FALLING TO -10C TO -12C ON WEDNESDAY MORNING) AND TERRAIN
ENHANCEMENT (PERSISTENT LOW LEVEL NORTHWESTERLY FLOW). WILL CONTINUE
TO FOCUS THE HIGHEST POPS (LIKELY VALUES) IN THOSE AREAS FAVORED BY
ALL THREE FEATURES (HIGHER TERRAIN OF THE WEST/NORTHWEST) AND ALSO
EAST DOWNWIND OF LAKE SUPERIOR...AND INCLUDE CHANCE/SLIGHTS FOR THE
REST OF THE CWA. WITH THE AMOUNT OF COLD AIR IN PLACE...EXPECT THE
PRECIPITATION TO FALL MAINLY AS SNOW. WITH LOW LEVEL TEMPERATURES
WARMING AWAY OVER THE SOUTHERN THIRD OF THE CWA...COULD SEE SOME
RAIN MIXING IN THERE...BUT OTHERWISE SNOW WILL BE THE NORM. COULD
SEE A COUPLE INCHES OF ACCUMULATION IN THE FAVORED LOCATIONS
TUESDAY NIGHT AND UP TO AN INCH WEDNESDAY AND AGAIN WEDNESDAY
NIGHT. WITH DRIER AIR STARTING TO MOVE INTO THE AREA ON
THURSDAY (ASSOCIATED WITH A SURFACE RIDGE MOVING INTO THE
NORTHERN PLAINS...SHOULD SEE THE COVERAGE OF THE SHOWERS
DIMINISHING THROUGH THE DAY THURSDAY AND CONTINUING TO WEAKENING
INTO FRIDAY. ALSO...DON/T EXPECT HIGHS TO RISE MUCH OUT OF THE
LOW-MID 30S ON WED/THURS OVER THE NORTH HALF OF THE CWA...WITH SOME
HIGHS AROUND 40 OVER THE SOUTH CENTRAL. WILL LIKELY BREAK THE
RECORD LOW HIGH TEMPERATURE HERE AT OUR OFFICE ON WEDNESDAY (36 SET
IN 1972).

EXTENDED RANGE MODELS DIFFER ON HOW QUICKLY THE UPPER LOW DEPARTS
THIS WEEKEND...BUT SHOULD STILL SEE ENOUGH INFLUENCE FROM THE
SURFACE RIDGE MOVING INTO THE NORTHERN PLAINS TO KEEP MOST OF THE
AREA DRY. WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR...EXPECT
TEMPERATURES TO REMAIN BELOW NORMAL BUT IN THE 40S TO AROUND 50. AS
THE UPPER LOW RETROGRADES BACK OVER QUEBEC EARLY NEXT WEEK...COULD
SEE THE UPPER GREAT LAKES REGION BEING AFFECTED BY THE WESTERN EDGE
OF THE ENERGY ROTATING AROUND THE UPPER LOW AND LIKELY KEEPING
BELOW NORMAL TEMPERATURES IN PLACE THROUGH THE END OF APRIL.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 131 PM EDT MON APR 20 2015

AREA OF DEEPER MSTR ASSOCIATED WITH BAND OF SHARPER FORCING WL BRING
A PERIOD OF STEADY SN TO CMX THRU THIS AFTN ALONG WITH LIFR
CONDITIONS. GUSTY W WINDS TO NEAR 30 KTS WL ALSO IMPACT THIS MORE
EXPOSED LOCATION. THE AREA OF PCPN WL EXIT IWD SOON AFTER TAF
ISSUANCE...SO EXPECT AN IMPROVEMENT THERE FM IFR TO MVFR WITH THE
ARRIVAL OF SOME DRIER AIR/SUBSIDENCE. SINCE THE BAND OF HEAVIER PCPN
IS LIKELY TO REMAIN TO THE W OF SAW...THERE SHOULD BE MVFR CIGS WITH
ONLY SOME OCNL -SHRA IN THE PRESENCE OF A DOWNSLOPE WIND COMPONENT.
FOR THIS EVNG...MVFR CONDITIONS SHOULD BE THE RULE WITH MVFR CIGS
AND ONLY SOME SCT LIGHT -SHSN OR -SHSNRA. BUT THE APRCH OF ANOTHER
DISTURBANCE/LO PRES TROF LATE TNGT SHOULD RESULT IN DETERIORATING
CONDITIONS AGAIN WITH IFR CONDITIONS DVLPG AT IWD AND CMX. DOWNSLOPE
WINDS AT SAW WL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO IWD AND CMX BY LATE MRNG ON TUE.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 353 PM EDT MON APR 20 2015

SHARP PRES GRADIENT ON THE SW FLANK OF SLOW MOVING LO PRES IN
ONTARIO WILL CAUSE W TO NW WINDS UP TO 25-30 KTS INTO THU. ALTHOUGH
THERE COULD BE SOME GALE FORCE GUSTS AT TIMES...WIDESPREAD GALES ARE
NOT EXPECTED. THE CLOSER APPROACH OF HI PRES LATER IN THE WEEK WILL
RESULT IN NW WINDS DIMINISHING TO NO MORE THAN 20 KTS ON FRI AND
SAT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC




000
FXUS63 KMQT 201953
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
353 PM EDT MON APR 20 2015

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 353 PM EDT MON APR 20 2015

12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEPENING UPR TROF
OVER CENTRAL NAMERICA BTWN RDGS ALONG THE E AND W COASTS...WITH 12HR
H5 HGT FALLS UP TO 150M NOTED OVER NRN WI IN ADVANCE OF SHRTWV
LIFTING NWD INTO THE UPR LKS TO THE E OF THE UPR TROF AXIS. IR AND
WV IMAGERY SHOW A WELL DEFINED COMMA HEAD CLD OVER THE UPR GREAT LKS
IN ADVANCE OF SHRTWV AND ON CYC SIDE OF ACCOMPANYING H7 LO TRACK.
STEADY RA UNDER THIS COMMA HEAD HAS MIXED WITH SN OVER THE WRN CWA
WHERE DYNAMIC COOLING AND SOME LLVL CAA HAVE COOLED THE COLUMN
SUFFICIENTLY. FARTHER TO THE E...DRY SLOTTING ON THE ACYC SIDE OF H7
LO TRACK HAS TENDED TO DIMINISH THE PCPN COVERAGE/INTENSITY OVER THE
FAR E. ANOTHER SHRTWV IS DIGGING SWD THRU FAR NW ONTARIO/MANITOBA ON
THE WRN FLANK OF H5 CLOSED LO

MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/PTYPE ASSOCIATED
WITH SHRTWV MOVING THRU THE UPR LKS RIGHT NOW AND THEN TNGT/TMRW
ACCOMPANYING PASSAGE OF NEXT SHRTWV AND WITHIN LINGERING DEEP CYC
FLOW UNDER CUTOFF H5 LO PROGGED TO LINGER OVER THE UPR LKS.

LATE TDAY/TNGT...AS SHRTWV E OF THE UPR TROF AXIS LIFTS TO THE N
THRU THIS AFTN AND TENDS TO SHEAR OUT...MODELS SHOW AREA OF SHARP
DEEP LYR QVECTOR CNVGC SUPPORTING AXIS OF COLDER CLD TOPS
DIMINISHING AND GIVING WAY TO SOME DEEP LYR QVECTOR DVGC. SO AREA OF
STEADY RA/SN OVER THE W SHOULD DIMINISH BY LATE AFTN WITH ARRIVAL OF
THE NEGATIVE DYNAMICS/MID LVL DRYING. POPS OVER THE E WL TEND TO
INCREASE LATE THIS AFTN/EARLY EVNG AS COMMA TAIL AXIS OF HIER RH
SWINGS E THRU THAT AREA...BUT PCPN INTENSITY WL NOT BE AS GREAT AS
OVER THE W SINCE THE SUPPORTING AXIS OF DIMINISHING DEEP LYR QVECTOR
CNVGC IS FCST TO REMAIN OVER THE W. NOT OUT OF THE QUESTION THERE
COULD BE A FEW INCHES OF WET SN ACCUM OVER THE HIER TERRAIN OF THE
W...BUT THERE SHOULD BE LTL IF ANY SN OVER THE E HALF WITH WEAKER
DYNAMIC FORCING/COOLING. LATER TNGT...THE TRAILING SHRTWV DIGGING
SWD TOWARD NW MN ON THE WRN FLANK OF CLOSED H5 LO IS FCST TO DIG TO
NEAR NW WI BY 12Z TUE...BRINGING SOME DPVA/MORE DEEP LYR QVECTOR
CNVGC TO THE W LATER TNGT. SHARP CYC UPSLOPE WNW FLOW IN THE
PRESENCE OF THE DEEPER FORCING/MSTR WL SUPPORT LIKELY POPS IN THIS
AREA. THERE COULD BE A FEW INCHES OF WET SN ACCUM OVER MAINLY THE
HIER TERRAIN. OVER THE CENTRAL AND E...THERE WL BE ONLY ISOLD-SCT RA
AND SN SHOWERS.

TUE...SHRTWV/ACCOMPANYING SFC LO PRES TROF ROTATING ARND CLOSED H5
LO SHIFTING SLOWLY TO THE E OVER LK SUP IS FCST TO WEAKEN SLOWLY...
LEADING TO SLOWLY DIMINISHING DEEP LYR QVECTOR CNVGC. ALTHOUGH THESE
TRENDS WL RESULT IN DIMINISHING POPS...DAYTIME HEATING/LLVL
DESTABILIZATION WL ENHANCE POPS ESPECIALLY OVER THE ERN CWA IN THE
AFTN...WHERE LLVL CNVGC WITHIN LO PRES TROF WL BE ENHANCED BY LK
BREEZE DEVELOPMENT. OTRW...LINGERING SHARP LLVL CNVGC AND THE
DAYTIME HEATING WL MAINTAIN AT LEAST CHC POPS. THE PCPN SHOULD BE
MAINLY SN IN THE MRNG...BUT THIS PCPN WL MIX WITH/CHG TO RA OVER THE
SE HALF IN THE AFTN WITH DAYTIME HEATING/TEMPS RISING AOA 40.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 PM EDT MON APR 20 2015

A LARGE UPPER LOW CENTERED OVER NORTHERN ONTARIO WILL BE
INFLUENCING THE GREAT LAKES REGION THROUGH THE FIRST HALF OF THE
LONG TERM PERIOD. THIS WILL LEAD TO BELOW NORMAL TEMPERATURES AND
PERIODS OF SNOW BEFORE GRADUALLY SHIFTING EAST INTO THE ATLANTIC BY
THE WEEKEND.

AS THAT UPPER LOW SPINS BETWEEN LAKE SUPERIOR AND JAMES BAY...IT
WILL ROTATE SEVERAL SHORTWAVES ACROSS THE UPPER GREAT LAKES REGION
TUESDAY NIGHT THROUGH THURSDAY. THESE WAVES WILL BRING PERIODS OF
SHOWERS TO THE AREA...WITH HELP FROM BOTH LAKE SUPERIOR (850MB
TEMPS FALLING TO -10C TO -12C ON WEDNESDAY MORNING) AND TERRAIN
ENHANCEMENT (PERSISTENT LOW LEVEL NORTHWESTERLY FLOW). WILL CONTINUE
TO FOCUS THE HIGHEST POPS (LIKELY VALUES) IN THOSE AREAS FAVORED BY
ALL THREE FEATURES (HIGHER TERRAIN OF THE WEST/NORTHWEST) AND ALSO
EAST DOWNWIND OF LAKE SUPERIOR...AND INCLUDE CHANCE/SLIGHTS FOR THE
REST OF THE CWA. WITH THE AMOUNT OF COLD AIR IN PLACE...EXPECT THE
PRECIPITATION TO FALL MAINLY AS SNOW. WITH LOW LEVEL TEMPERATURES
WARMING AWAY OVER THE SOUTHERN THIRD OF THE CWA...COULD SEE SOME
RAIN MIXING IN THERE...BUT OTHERWISE SNOW WILL BE THE NORM. COULD
SEE A COUPLE INCHES OF ACCUMULATION IN THE FAVORED LOCATIONS
TUESDAY NIGHT AND UP TO AN INCH WEDNESDAY AND AGAIN WEDNESDAY
NIGHT. WITH DRIER AIR STARTING TO MOVE INTO THE AREA ON
THURSDAY (ASSOCIATED WITH A SURFACE RIDGE MOVING INTO THE
NORTHERN PLAINS...SHOULD SEE THE COVERAGE OF THE SHOWERS
DIMINISHING THROUGH THE DAY THURSDAY AND CONTINUING TO WEAKENING
INTO FRIDAY. ALSO...DON/T EXPECT HIGHS TO RISE MUCH OUT OF THE
LOW-MID 30S ON WED/THURS OVER THE NORTH HALF OF THE CWA...WITH SOME
HIGHS AROUND 40 OVER THE SOUTH CENTRAL. WILL LIKELY BREAK THE
RECORD LOW HIGH TEMPERATURE HERE AT OUR OFFICE ON WEDNESDAY (36 SET
IN 1972).

EXTENDED RANGE MODELS DIFFER ON HOW QUICKLY THE UPPER LOW DEPARTS
THIS WEEKEND...BUT SHOULD STILL SEE ENOUGH INFLUENCE FROM THE
SURFACE RIDGE MOVING INTO THE NORTHERN PLAINS TO KEEP MOST OF THE
AREA DRY. WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR...EXPECT
TEMPERATURES TO REMAIN BELOW NORMAL BUT IN THE 40S TO AROUND 50. AS
THE UPPER LOW RETROGRADES BACK OVER QUEBEC EARLY NEXT WEEK...COULD
SEE THE UPPER GREAT LAKES REGION BEING AFFECTED BY THE WESTERN EDGE
OF THE ENERGY ROTATING AROUND THE UPPER LOW AND LIKELY KEEPING
BELOW NORMAL TEMPERATURES IN PLACE THROUGH THE END OF APRIL.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 131 PM EDT MON APR 20 2015

AREA OF DEEPER MSTR ASSOCIATED WITH BAND OF SHARPER FORCING WL BRING
A PERIOD OF STEADY SN TO CMX THRU THIS AFTN ALONG WITH LIFR
CONDITIONS. GUSTY W WINDS TO NEAR 30 KTS WL ALSO IMPACT THIS MORE
EXPOSED LOCATION. THE AREA OF PCPN WL EXIT IWD SOON AFTER TAF
ISSUANCE...SO EXPECT AN IMPROVEMENT THERE FM IFR TO MVFR WITH THE
ARRIVAL OF SOME DRIER AIR/SUBSIDENCE. SINCE THE BAND OF HEAVIER PCPN
IS LIKELY TO REMAIN TO THE W OF SAW...THERE SHOULD BE MVFR CIGS WITH
ONLY SOME OCNL -SHRA IN THE PRESENCE OF A DOWNSLOPE WIND COMPONENT.
FOR THIS EVNG...MVFR CONDITIONS SHOULD BE THE RULE WITH MVFR CIGS
AND ONLY SOME SCT LIGHT -SHSN OR -SHSNRA. BUT THE APRCH OF ANOTHER
DISTURBANCE/LO PRES TROF LATE TNGT SHOULD RESULT IN DETERIORATING
CONDITIONS AGAIN WITH IFR CONDITIONS DVLPG AT IWD AND CMX. DOWNSLOPE
WINDS AT SAW WL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO IWD AND CMX BY LATE MRNG ON TUE.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 353 PM EDT MON APR 20 2015

SHARP PRES GRADIENT ON THE SW FLANK OF SLOW MOVING LO PRES IN
ONTARIO WILL CAUSE W TO NW WINDS UP TO 25-30 KTS INTO THU. ALTHOUGH
THERE COULD BE SOME GALE FORCE GUSTS AT TIMES...WIDESPREAD GALES ARE
NOT EXPECTED. THE CLOSER APPROACH OF HI PRES LATER IN THE WEEK WILL
RESULT IN NW WINDS DIMINISHING TO NO MORE THAN 20 KTS ON FRI AND
SAT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC



000
FXUS63 KMQT 201953
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
353 PM EDT MON APR 20 2015

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 353 PM EDT MON APR 20 2015

12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEPENING UPR TROF
OVER CENTRAL NAMERICA BTWN RDGS ALONG THE E AND W COASTS...WITH 12HR
H5 HGT FALLS UP TO 150M NOTED OVER NRN WI IN ADVANCE OF SHRTWV
LIFTING NWD INTO THE UPR LKS TO THE E OF THE UPR TROF AXIS. IR AND
WV IMAGERY SHOW A WELL DEFINED COMMA HEAD CLD OVER THE UPR GREAT LKS
IN ADVANCE OF SHRTWV AND ON CYC SIDE OF ACCOMPANYING H7 LO TRACK.
STEADY RA UNDER THIS COMMA HEAD HAS MIXED WITH SN OVER THE WRN CWA
WHERE DYNAMIC COOLING AND SOME LLVL CAA HAVE COOLED THE COLUMN
SUFFICIENTLY. FARTHER TO THE E...DRY SLOTTING ON THE ACYC SIDE OF H7
LO TRACK HAS TENDED TO DIMINISH THE PCPN COVERAGE/INTENSITY OVER THE
FAR E. ANOTHER SHRTWV IS DIGGING SWD THRU FAR NW ONTARIO/MANITOBA ON
THE WRN FLANK OF H5 CLOSED LO

MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON POPS/PTYPE ASSOCIATED
WITH SHRTWV MOVING THRU THE UPR LKS RIGHT NOW AND THEN TNGT/TMRW
ACCOMPANYING PASSAGE OF NEXT SHRTWV AND WITHIN LINGERING DEEP CYC
FLOW UNDER CUTOFF H5 LO PROGGED TO LINGER OVER THE UPR LKS.

LATE TDAY/TNGT...AS SHRTWV E OF THE UPR TROF AXIS LIFTS TO THE N
THRU THIS AFTN AND TENDS TO SHEAR OUT...MODELS SHOW AREA OF SHARP
DEEP LYR QVECTOR CNVGC SUPPORTING AXIS OF COLDER CLD TOPS
DIMINISHING AND GIVING WAY TO SOME DEEP LYR QVECTOR DVGC. SO AREA OF
STEADY RA/SN OVER THE W SHOULD DIMINISH BY LATE AFTN WITH ARRIVAL OF
THE NEGATIVE DYNAMICS/MID LVL DRYING. POPS OVER THE E WL TEND TO
INCREASE LATE THIS AFTN/EARLY EVNG AS COMMA TAIL AXIS OF HIER RH
SWINGS E THRU THAT AREA...BUT PCPN INTENSITY WL NOT BE AS GREAT AS
OVER THE W SINCE THE SUPPORTING AXIS OF DIMINISHING DEEP LYR QVECTOR
CNVGC IS FCST TO REMAIN OVER THE W. NOT OUT OF THE QUESTION THERE
COULD BE A FEW INCHES OF WET SN ACCUM OVER THE HIER TERRAIN OF THE
W...BUT THERE SHOULD BE LTL IF ANY SN OVER THE E HALF WITH WEAKER
DYNAMIC FORCING/COOLING. LATER TNGT...THE TRAILING SHRTWV DIGGING
SWD TOWARD NW MN ON THE WRN FLANK OF CLOSED H5 LO IS FCST TO DIG TO
NEAR NW WI BY 12Z TUE...BRINGING SOME DPVA/MORE DEEP LYR QVECTOR
CNVGC TO THE W LATER TNGT. SHARP CYC UPSLOPE WNW FLOW IN THE
PRESENCE OF THE DEEPER FORCING/MSTR WL SUPPORT LIKELY POPS IN THIS
AREA. THERE COULD BE A FEW INCHES OF WET SN ACCUM OVER MAINLY THE
HIER TERRAIN. OVER THE CENTRAL AND E...THERE WL BE ONLY ISOLD-SCT RA
AND SN SHOWERS.

TUE...SHRTWV/ACCOMPANYING SFC LO PRES TROF ROTATING ARND CLOSED H5
LO SHIFTING SLOWLY TO THE E OVER LK SUP IS FCST TO WEAKEN SLOWLY...
LEADING TO SLOWLY DIMINISHING DEEP LYR QVECTOR CNVGC. ALTHOUGH THESE
TRENDS WL RESULT IN DIMINISHING POPS...DAYTIME HEATING/LLVL
DESTABILIZATION WL ENHANCE POPS ESPECIALLY OVER THE ERN CWA IN THE
AFTN...WHERE LLVL CNVGC WITHIN LO PRES TROF WL BE ENHANCED BY LK
BREEZE DEVELOPMENT. OTRW...LINGERING SHARP LLVL CNVGC AND THE
DAYTIME HEATING WL MAINTAIN AT LEAST CHC POPS. THE PCPN SHOULD BE
MAINLY SN IN THE MRNG...BUT THIS PCPN WL MIX WITH/CHG TO RA OVER THE
SE HALF IN THE AFTN WITH DAYTIME HEATING/TEMPS RISING AOA 40.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 PM EDT MON APR 20 2015

A LARGE UPPER LOW CENTERED OVER NORTHERN ONTARIO WILL BE
INFLUENCING THE GREAT LAKES REGION THROUGH THE FIRST HALF OF THE
LONG TERM PERIOD. THIS WILL LEAD TO BELOW NORMAL TEMPERATURES AND
PERIODS OF SNOW BEFORE GRADUALLY SHIFTING EAST INTO THE ATLANTIC BY
THE WEEKEND.

AS THAT UPPER LOW SPINS BETWEEN LAKE SUPERIOR AND JAMES BAY...IT
WILL ROTATE SEVERAL SHORTWAVES ACROSS THE UPPER GREAT LAKES REGION
TUESDAY NIGHT THROUGH THURSDAY. THESE WAVES WILL BRING PERIODS OF
SHOWERS TO THE AREA...WITH HELP FROM BOTH LAKE SUPERIOR (850MB
TEMPS FALLING TO -10C TO -12C ON WEDNESDAY MORNING) AND TERRAIN
ENHANCEMENT (PERSISTENT LOW LEVEL NORTHWESTERLY FLOW). WILL CONTINUE
TO FOCUS THE HIGHEST POPS (LIKELY VALUES) IN THOSE AREAS FAVORED BY
ALL THREE FEATURES (HIGHER TERRAIN OF THE WEST/NORTHWEST) AND ALSO
EAST DOWNWIND OF LAKE SUPERIOR...AND INCLUDE CHANCE/SLIGHTS FOR THE
REST OF THE CWA. WITH THE AMOUNT OF COLD AIR IN PLACE...EXPECT THE
PRECIPITATION TO FALL MAINLY AS SNOW. WITH LOW LEVEL TEMPERATURES
WARMING AWAY OVER THE SOUTHERN THIRD OF THE CWA...COULD SEE SOME
RAIN MIXING IN THERE...BUT OTHERWISE SNOW WILL BE THE NORM. COULD
SEE A COUPLE INCHES OF ACCUMULATION IN THE FAVORED LOCATIONS
TUESDAY NIGHT AND UP TO AN INCH WEDNESDAY AND AGAIN WEDNESDAY
NIGHT. WITH DRIER AIR STARTING TO MOVE INTO THE AREA ON
THURSDAY (ASSOCIATED WITH A SURFACE RIDGE MOVING INTO THE
NORTHERN PLAINS...SHOULD SEE THE COVERAGE OF THE SHOWERS
DIMINISHING THROUGH THE DAY THURSDAY AND CONTINUING TO WEAKENING
INTO FRIDAY. ALSO...DON/T EXPECT HIGHS TO RISE MUCH OUT OF THE
LOW-MID 30S ON WED/THURS OVER THE NORTH HALF OF THE CWA...WITH SOME
HIGHS AROUND 40 OVER THE SOUTH CENTRAL. WILL LIKELY BREAK THE
RECORD LOW HIGH TEMPERATURE HERE AT OUR OFFICE ON WEDNESDAY (36 SET
IN 1972).

EXTENDED RANGE MODELS DIFFER ON HOW QUICKLY THE UPPER LOW DEPARTS
THIS WEEKEND...BUT SHOULD STILL SEE ENOUGH INFLUENCE FROM THE
SURFACE RIDGE MOVING INTO THE NORTHERN PLAINS TO KEEP MOST OF THE
AREA DRY. WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR...EXPECT
TEMPERATURES TO REMAIN BELOW NORMAL BUT IN THE 40S TO AROUND 50. AS
THE UPPER LOW RETROGRADES BACK OVER QUEBEC EARLY NEXT WEEK...COULD
SEE THE UPPER GREAT LAKES REGION BEING AFFECTED BY THE WESTERN EDGE
OF THE ENERGY ROTATING AROUND THE UPPER LOW AND LIKELY KEEPING
BELOW NORMAL TEMPERATURES IN PLACE THROUGH THE END OF APRIL.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 131 PM EDT MON APR 20 2015

AREA OF DEEPER MSTR ASSOCIATED WITH BAND OF SHARPER FORCING WL BRING
A PERIOD OF STEADY SN TO CMX THRU THIS AFTN ALONG WITH LIFR
CONDITIONS. GUSTY W WINDS TO NEAR 30 KTS WL ALSO IMPACT THIS MORE
EXPOSED LOCATION. THE AREA OF PCPN WL EXIT IWD SOON AFTER TAF
ISSUANCE...SO EXPECT AN IMPROVEMENT THERE FM IFR TO MVFR WITH THE
ARRIVAL OF SOME DRIER AIR/SUBSIDENCE. SINCE THE BAND OF HEAVIER PCPN
IS LIKELY TO REMAIN TO THE W OF SAW...THERE SHOULD BE MVFR CIGS WITH
ONLY SOME OCNL -SHRA IN THE PRESENCE OF A DOWNSLOPE WIND COMPONENT.
FOR THIS EVNG...MVFR CONDITIONS SHOULD BE THE RULE WITH MVFR CIGS
AND ONLY SOME SCT LIGHT -SHSN OR -SHSNRA. BUT THE APRCH OF ANOTHER
DISTURBANCE/LO PRES TROF LATE TNGT SHOULD RESULT IN DETERIORATING
CONDITIONS AGAIN WITH IFR CONDITIONS DVLPG AT IWD AND CMX. DOWNSLOPE
WINDS AT SAW WL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO IWD AND CMX BY LATE MRNG ON TUE.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 353 PM EDT MON APR 20 2015

SHARP PRES GRADIENT ON THE SW FLANK OF SLOW MOVING LO PRES IN
ONTARIO WILL CAUSE W TO NW WINDS UP TO 25-30 KTS INTO THU. ALTHOUGH
THERE COULD BE SOME GALE FORCE GUSTS AT TIMES...WIDESPREAD GALES ARE
NOT EXPECTED. THE CLOSER APPROACH OF HI PRES LATER IN THE WEEK WILL
RESULT IN NW WINDS DIMINISHING TO NO MORE THAN 20 KTS ON FRI AND
SAT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC




000
FXUS63 KDTX 201946
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
346 PM EDT MON APR 20 2015

.SHORT TERM...TONIGHT

MUCAPES DID REACH 500 TO 800 J/KG EARLIER THIS AFTERNOON (PER LAPS
DATA)...WHICH WAS ABLE TO SUPPORT A COUPLE THUNDERSTORMS OVER
SOUTHEAST MICHIGAN. BULK OF CONVECTIVE ACTIVITY HAS PUSHED
EAST...AND CONTINUED DRYING BEHIND THE COLD FRONT WILL OCCUR...AS
SURFACE DEW PTS CRASH INTO THE 40S. WITH THAT COLDER/DRY AIR PUSH
IS SOME GUSTY WINDS...AS SOME PEAK WINDS OF 35 TO 45 MPH CAN BE
EXPECTED FOR ANOTHER COUPLE OF HOURS AS WE EXIT PEAK HEATING.
NOTED PEAK WIND AT DTW OF 42 KNOTS AT 1855Z. NAM/GFS MODEL
SOUNDINGS/LOW LEVEL RH FIELDS SUGGEST WE ARE GOING TO PARTIALLY
CLEAR OUT TONIGHT...BUT UPSTREAM OBSERVATIONS EXTENDING BACK WEST
OVER THE WESTERN GREAT LAKES/UPPER MISSISSIPPI RIVER VALLEY TO NOT
LOOK VERY ENCOURAGING...AND PREFERENCE WAS TO INCREASE THE CLOUD
COVER FORECAST FOR TONIGHT WITH THE COLD CYCLONIC FLOW. ALSO...AS
850 MB TEMPS FALL INTO THE MID NEGATIVE SINGLE NUMBERS OVER LAKE
MICHIGAN...SOME LAKE MICHIGAN MOISTURE/INSTABILITY CONTRIBUTION IS
NOT OUT OF THE QUESTION. HAVE CARRIED ISOLATED-SCATTERED LIGHT
RAIN SHOWER MENTION TO ACCOUNT FOR LINGERING ACTIVITY LATE THIS
AFTERNOON/EARLY THIS EVENING AND THEN THE POSSIBLE ACTIVITY TOWARD
MORNING. DESPITE CLOUDS...COLD ADVECTION EXPECTED TO SEND MINS
INTO THE UPPER 30S TO LOWER 40S.

&&

.LONG TERM...

A BROAD UPPER LEVEL TROUGH WITH A CLOSED LOW IN CLOSE PROXIMITY TO
THE GREAT LAKES REGION WILL KEEP SOUTHEASTERN MICHIGAN UNDER THE
INFLUENCE OF COLD CYCLONIC FLOW THROUGHOUT THE MIDWEEK PERIOD.
NATURE OF INDIVIDUAL SHORTWAVES ROTATING AROUND THIS UPPER LEVEL
FEATURE KEEPS THE SPECIFIC TIMING CONFIDENCE INHERENTLY LOW.

MAGNITUDE OF COLD AND DRY AIR ADVECTION FROM TONIGHT WILL
PRECONDITION THE ATMOSPHERE AND ALLOW FOR THE GROWTH OF A DEEP
DIURNAL NEAR SURFACE MIXED LAYER ON TUESDAY. FORECAST SOUNDINGS
SUGGEST MIXING HEIGHTS REACHING AS HIGH AS 6 TO 7 KFT AGL BY THE
AFTERNOON HOURS. GEOSTROPHIC FLOW IN THE REGION WILL REMAIN ELEVATED
WITH THE LOW HEIGHT ANOMALY OVER CENTRAL ONTARIO WHICH SUPPORTS
WIDESPREAD WESTERLY WIND GUSTS LATE TUESDAY MORNING/TUESDAY
AFTERNOON IN EXCESS OF 30 KNOTS. COMBINATION OF SHORTWAVE ENERGY
WORKING THROUGH THE TROUGH AXIS AND SPOKES OF ENHANCED MIDLEVEL
CONVERGENCE/SATURATION WILL BRING THE POTENTIAL FOR RAIN SHOWERS BY
TUESDAY MORNING. POTENTIAL MEDIUM IMPACT WEATHER SCENARIO MAY
UNFOLD...CONTINGENT ON OVERALL EFFICIENCY OF INDIVIDUAL CONVECTIVE
CIRCULATIONS OF THE SHOWERS TO ENHANCE DOWNWARD MOMENTUM TRANSPORT.
AFOREMENTIONED FORECAST DISCUSSION MADE REFERENCE TO A CLASSIC
INVERTED V STRUCTURE...WHICH SUGGESTS SOME POSSIBILITY THAT
WINDGUSTS COULD REACH 50 MPH. FUTURE SHIFTS CAN ASSESS THE
FEASIBILITY OF A POSSIBLE WIND ADVISORY FOR WEDNESDAY AFTERNOON.

PERSISTENT CYCLONIC FLOW AROUND UPPER LEVEL CLOSED LOW WILL BRING
ANOTHER DAY OF COLD AND SHOWERY TO SOUTHEASTERN MICHIGAN ON
WEDNESDAY. A SECONDARY SURGE OF COLD AIR ADVECTION IS FORECASTED
BETWEEN 15-18Z. THE CAA SHOULD WORK AGAINST DIURNAL HEATING...WITH
HIGHS SOME 7 TO 10 DEGREES COOLER THAN THE DAY BEFORE. HIGHS ON
WEDNESDAY ARE ONLY EXPECTED TO REACH THE MIDDLE TO UPPER 40S. BETTER
MESSAGE TO COMMUNICATE IS THAT WIND CHILLS FOR MANY AREAS WILL NOT
CLIMB OUT OF THE 30S.

THE REGION WILL STILL BE UNDER THE INFLUENCE OF LONGWAVE TROUGHING
ON THURSDAY BEFORE WEAK UPPER LEVEL RIDGING BUILDS IN FOR THE START
OF THE WEEKEND.  THIS TROUGH WILL CONTINUE TO LEAD TO COOLER TEMPS
THURSDAY BEFORE TEMPERATURES MODERATE A TINY BIT BACK INTO THE 50S
BY THE WEEKEND.  AT THIS POINT THE ONLY POTENTIAL FOR POSSIBLE
PRECIP IN THE EXTENDED WOULD BE ON SATURDAY...ALTHOUGH MOST MODELS
ARE KEEPING THE BULK OF THE PRECIP SOUTH OF THE CWA WITH THE
EXCEPTION OF THE 12Z ECMWF.

&&

.MARINE...

STRONG SOUTHWESTERLY WIND FIELD IS NOW IN PLACE WITH WINDSPEEDS AREA
WIDE RANGING BETWEEN 25 AND 35 KNOTS. SMALL CRAFT ADVISORIES REMAIN
IN EFFECT FOR ALL NEARSHORE ZONES. BREEZY WESTERLY WINDS WILL
PERSIST THROUGH MIDWEEK AS CONDITIONS REMAIN RELATIVELY STATIC WITH
LOW PRESSURE PARKED OVER THE GREAT LAKES. ADDITIONAL SMALL CRAFT
ADVISORIES FOR WIND WILL LIKELY BE NEEDED ON TUESDAY AND POSSIBLY
ONCE MORE ON WEDNESDAY.

&&

.AVIATION...ISSUED 118 PM EDT MON APR 20 2015

DISORGANIZED SHOWERS WORKING THROUGH SOUTHEAST MICHIGAN THIS
AFTERNOON AHEAD OF A COLD FRONT... WITH STILL LOW CHANCE OF ISOLATED
THUNDERSTORM DEVELOPING. WINDS WILL BE GUSTING BETWEEN 30 TO 40
KNOTS WITHIN ANY OF THE STRONGER SHOWERS. MVFR/LOW VFR CEILINGS
WILL HOLD INTO THE EARLY EVENING HOURS...AND STILL COULD BE
ISOLATED-SCATTERED LIGHT RAIN SHOWERS LEFT OVER...BUT WINDS
SHIFTING A BIT MORE SOUTHWEST-WEST BEHIND THE COLD FRONT WILL
ALLOW FOR A DRYING TREND. CLOUD COVER TONIGHT IS SOMEWHAT
UNCERTAIN AS COLD CYCLONIC FLOW OFF LAKE MICHIGAN MAY BE
SUFFICIENT TO MAINTAIN THE LOW VFR/BORDERLINE MVFR CEILINGS. IF
SKIES DO SCATTER OUT TONIGHT...HIGHER CONFIDENCE IN LOW VFR
CEILINGS REDEVELOPING TOMORROW MORNING...WITH POSSIBLY ENOUGH
INSTABILITY TO GENERATE SCATTERED SHOWERS DURING THE DAY. IT WILL
BE WINDY...ESPECIALLY UNDERNEATH ANY SHOWERS...AS WINDS COULD GUST
IN EXCESS OF 35 KNOTS.

FOR DTW...SHOWERS WILL BE CLEARING THE TERMINAL AT THE START OF THE
TAF PERIOD. THERE IS A CHANCE OF A COUPLE LIGHT RAIN SHOWERS EARLY
THIS EVENING...BUT AREA COVERAGE PRECLUDED THE MENTION.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CIGS AOB 5KFT THROUGH EARLY EARLY EVENING...THEN
  MEDIUM CONFIDENCE.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LHZ421-422-
     441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LEZ444.

&&

$$

SHORT TERM...SF
LONG TERM....CB/SS
MARINE.......CB
AVIATION.....SF


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).




000
FXUS63 KDTX 201946
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
346 PM EDT MON APR 20 2015

.SHORT TERM...TONIGHT

MUCAPES DID REACH 500 TO 800 J/KG EARLIER THIS AFTERNOON (PER LAPS
DATA)...WHICH WAS ABLE TO SUPPORT A COUPLE THUNDERSTORMS OVER
SOUTHEAST MICHIGAN. BULK OF CONVECTIVE ACTIVITY HAS PUSHED
EAST...AND CONTINUED DRYING BEHIND THE COLD FRONT WILL OCCUR...AS
SURFACE DEW PTS CRASH INTO THE 40S. WITH THAT COLDER/DRY AIR PUSH
IS SOME GUSTY WINDS...AS SOME PEAK WINDS OF 35 TO 45 MPH CAN BE
EXPECTED FOR ANOTHER COUPLE OF HOURS AS WE EXIT PEAK HEATING.
NOTED PEAK WIND AT DTW OF 42 KNOTS AT 1855Z. NAM/GFS MODEL
SOUNDINGS/LOW LEVEL RH FIELDS SUGGEST WE ARE GOING TO PARTIALLY
CLEAR OUT TONIGHT...BUT UPSTREAM OBSERVATIONS EXTENDING BACK WEST
OVER THE WESTERN GREAT LAKES/UPPER MISSISSIPPI RIVER VALLEY TO NOT
LOOK VERY ENCOURAGING...AND PREFERENCE WAS TO INCREASE THE CLOUD
COVER FORECAST FOR TONIGHT WITH THE COLD CYCLONIC FLOW. ALSO...AS
850 MB TEMPS FALL INTO THE MID NEGATIVE SINGLE NUMBERS OVER LAKE
MICHIGAN...SOME LAKE MICHIGAN MOISTURE/INSTABILITY CONTRIBUTION IS
NOT OUT OF THE QUESTION. HAVE CARRIED ISOLATED-SCATTERED LIGHT
RAIN SHOWER MENTION TO ACCOUNT FOR LINGERING ACTIVITY LATE THIS
AFTERNOON/EARLY THIS EVENING AND THEN THE POSSIBLE ACTIVITY TOWARD
MORNING. DESPITE CLOUDS...COLD ADVECTION EXPECTED TO SEND MINS
INTO THE UPPER 30S TO LOWER 40S.

&&

.LONG TERM...

A BROAD UPPER LEVEL TROUGH WITH A CLOSED LOW IN CLOSE PROXIMITY TO
THE GREAT LAKES REGION WILL KEEP SOUTHEASTERN MICHIGAN UNDER THE
INFLUENCE OF COLD CYCLONIC FLOW THROUGHOUT THE MIDWEEK PERIOD.
NATURE OF INDIVIDUAL SHORTWAVES ROTATING AROUND THIS UPPER LEVEL
FEATURE KEEPS THE SPECIFIC TIMING CONFIDENCE INHERENTLY LOW.

MAGNITUDE OF COLD AND DRY AIR ADVECTION FROM TONIGHT WILL
PRECONDITION THE ATMOSPHERE AND ALLOW FOR THE GROWTH OF A DEEP
DIURNAL NEAR SURFACE MIXED LAYER ON TUESDAY. FORECAST SOUNDINGS
SUGGEST MIXING HEIGHTS REACHING AS HIGH AS 6 TO 7 KFT AGL BY THE
AFTERNOON HOURS. GEOSTROPHIC FLOW IN THE REGION WILL REMAIN ELEVATED
WITH THE LOW HEIGHT ANOMALY OVER CENTRAL ONTARIO WHICH SUPPORTS
WIDESPREAD WESTERLY WIND GUSTS LATE TUESDAY MORNING/TUESDAY
AFTERNOON IN EXCESS OF 30 KNOTS. COMBINATION OF SHORTWAVE ENERGY
WORKING THROUGH THE TROUGH AXIS AND SPOKES OF ENHANCED MIDLEVEL
CONVERGENCE/SATURATION WILL BRING THE POTENTIAL FOR RAIN SHOWERS BY
TUESDAY MORNING. POTENTIAL MEDIUM IMPACT WEATHER SCENARIO MAY
UNFOLD...CONTINGENT ON OVERALL EFFICIENCY OF INDIVIDUAL CONVECTIVE
CIRCULATIONS OF THE SHOWERS TO ENHANCE DOWNWARD MOMENTUM TRANSPORT.
AFOREMENTIONED FORECAST DISCUSSION MADE REFERENCE TO A CLASSIC
INVERTED V STRUCTURE...WHICH SUGGESTS SOME POSSIBILITY THAT
WINDGUSTS COULD REACH 50 MPH. FUTURE SHIFTS CAN ASSESS THE
FEASIBILITY OF A POSSIBLE WIND ADVISORY FOR WEDNESDAY AFTERNOON.

PERSISTENT CYCLONIC FLOW AROUND UPPER LEVEL CLOSED LOW WILL BRING
ANOTHER DAY OF COLD AND SHOWERY TO SOUTHEASTERN MICHIGAN ON
WEDNESDAY. A SECONDARY SURGE OF COLD AIR ADVECTION IS FORECASTED
BETWEEN 15-18Z. THE CAA SHOULD WORK AGAINST DIURNAL HEATING...WITH
HIGHS SOME 7 TO 10 DEGREES COOLER THAN THE DAY BEFORE. HIGHS ON
WEDNESDAY ARE ONLY EXPECTED TO REACH THE MIDDLE TO UPPER 40S. BETTER
MESSAGE TO COMMUNICATE IS THAT WIND CHILLS FOR MANY AREAS WILL NOT
CLIMB OUT OF THE 30S.

THE REGION WILL STILL BE UNDER THE INFLUENCE OF LONGWAVE TROUGHING
ON THURSDAY BEFORE WEAK UPPER LEVEL RIDGING BUILDS IN FOR THE START
OF THE WEEKEND.  THIS TROUGH WILL CONTINUE TO LEAD TO COOLER TEMPS
THURSDAY BEFORE TEMPERATURES MODERATE A TINY BIT BACK INTO THE 50S
BY THE WEEKEND.  AT THIS POINT THE ONLY POTENTIAL FOR POSSIBLE
PRECIP IN THE EXTENDED WOULD BE ON SATURDAY...ALTHOUGH MOST MODELS
ARE KEEPING THE BULK OF THE PRECIP SOUTH OF THE CWA WITH THE
EXCEPTION OF THE 12Z ECMWF.

&&

.MARINE...

STRONG SOUTHWESTERLY WIND FIELD IS NOW IN PLACE WITH WINDSPEEDS AREA
WIDE RANGING BETWEEN 25 AND 35 KNOTS. SMALL CRAFT ADVISORIES REMAIN
IN EFFECT FOR ALL NEARSHORE ZONES. BREEZY WESTERLY WINDS WILL
PERSIST THROUGH MIDWEEK AS CONDITIONS REMAIN RELATIVELY STATIC WITH
LOW PRESSURE PARKED OVER THE GREAT LAKES. ADDITIONAL SMALL CRAFT
ADVISORIES FOR WIND WILL LIKELY BE NEEDED ON TUESDAY AND POSSIBLY
ONCE MORE ON WEDNESDAY.

&&

.AVIATION...ISSUED 118 PM EDT MON APR 20 2015

DISORGANIZED SHOWERS WORKING THROUGH SOUTHEAST MICHIGAN THIS
AFTERNOON AHEAD OF A COLD FRONT... WITH STILL LOW CHANCE OF ISOLATED
THUNDERSTORM DEVELOPING. WINDS WILL BE GUSTING BETWEEN 30 TO 40
KNOTS WITHIN ANY OF THE STRONGER SHOWERS. MVFR/LOW VFR CEILINGS
WILL HOLD INTO THE EARLY EVENING HOURS...AND STILL COULD BE
ISOLATED-SCATTERED LIGHT RAIN SHOWERS LEFT OVER...BUT WINDS
SHIFTING A BIT MORE SOUTHWEST-WEST BEHIND THE COLD FRONT WILL
ALLOW FOR A DRYING TREND. CLOUD COVER TONIGHT IS SOMEWHAT
UNCERTAIN AS COLD CYCLONIC FLOW OFF LAKE MICHIGAN MAY BE
SUFFICIENT TO MAINTAIN THE LOW VFR/BORDERLINE MVFR CEILINGS. IF
SKIES DO SCATTER OUT TONIGHT...HIGHER CONFIDENCE IN LOW VFR
CEILINGS REDEVELOPING TOMORROW MORNING...WITH POSSIBLY ENOUGH
INSTABILITY TO GENERATE SCATTERED SHOWERS DURING THE DAY. IT WILL
BE WINDY...ESPECIALLY UNDERNEATH ANY SHOWERS...AS WINDS COULD GUST
IN EXCESS OF 35 KNOTS.

FOR DTW...SHOWERS WILL BE CLEARING THE TERMINAL AT THE START OF THE
TAF PERIOD. THERE IS A CHANCE OF A COUPLE LIGHT RAIN SHOWERS EARLY
THIS EVENING...BUT AREA COVERAGE PRECLUDED THE MENTION.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CIGS AOB 5KFT THROUGH EARLY EARLY EVENING...THEN
  MEDIUM CONFIDENCE.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LHZ421-422-
     441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LEZ444.

&&

$$

SHORT TERM...SF
LONG TERM....CB/SS
MARINE.......CB
AVIATION.....SF


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).




000
FXUS63 KDTX 201946
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
346 PM EDT MON APR 20 2015

.SHORT TERM...TONIGHT

MUCAPES DID REACH 500 TO 800 J/KG EARLIER THIS AFTERNOON (PER LAPS
DATA)...WHICH WAS ABLE TO SUPPORT A COUPLE THUNDERSTORMS OVER
SOUTHEAST MICHIGAN. BULK OF CONVECTIVE ACTIVITY HAS PUSHED
EAST...AND CONTINUED DRYING BEHIND THE COLD FRONT WILL OCCUR...AS
SURFACE DEW PTS CRASH INTO THE 40S. WITH THAT COLDER/DRY AIR PUSH
IS SOME GUSTY WINDS...AS SOME PEAK WINDS OF 35 TO 45 MPH CAN BE
EXPECTED FOR ANOTHER COUPLE OF HOURS AS WE EXIT PEAK HEATING.
NOTED PEAK WIND AT DTW OF 42 KNOTS AT 1855Z. NAM/GFS MODEL
SOUNDINGS/LOW LEVEL RH FIELDS SUGGEST WE ARE GOING TO PARTIALLY
CLEAR OUT TONIGHT...BUT UPSTREAM OBSERVATIONS EXTENDING BACK WEST
OVER THE WESTERN GREAT LAKES/UPPER MISSISSIPPI RIVER VALLEY TO NOT
LOOK VERY ENCOURAGING...AND PREFERENCE WAS TO INCREASE THE CLOUD
COVER FORECAST FOR TONIGHT WITH THE COLD CYCLONIC FLOW. ALSO...AS
850 MB TEMPS FALL INTO THE MID NEGATIVE SINGLE NUMBERS OVER LAKE
MICHIGAN...SOME LAKE MICHIGAN MOISTURE/INSTABILITY CONTRIBUTION IS
NOT OUT OF THE QUESTION. HAVE CARRIED ISOLATED-SCATTERED LIGHT
RAIN SHOWER MENTION TO ACCOUNT FOR LINGERING ACTIVITY LATE THIS
AFTERNOON/EARLY THIS EVENING AND THEN THE POSSIBLE ACTIVITY TOWARD
MORNING. DESPITE CLOUDS...COLD ADVECTION EXPECTED TO SEND MINS
INTO THE UPPER 30S TO LOWER 40S.

&&

.LONG TERM...

A BROAD UPPER LEVEL TROUGH WITH A CLOSED LOW IN CLOSE PROXIMITY TO
THE GREAT LAKES REGION WILL KEEP SOUTHEASTERN MICHIGAN UNDER THE
INFLUENCE OF COLD CYCLONIC FLOW THROUGHOUT THE MIDWEEK PERIOD.
NATURE OF INDIVIDUAL SHORTWAVES ROTATING AROUND THIS UPPER LEVEL
FEATURE KEEPS THE SPECIFIC TIMING CONFIDENCE INHERENTLY LOW.

MAGNITUDE OF COLD AND DRY AIR ADVECTION FROM TONIGHT WILL
PRECONDITION THE ATMOSPHERE AND ALLOW FOR THE GROWTH OF A DEEP
DIURNAL NEAR SURFACE MIXED LAYER ON TUESDAY. FORECAST SOUNDINGS
SUGGEST MIXING HEIGHTS REACHING AS HIGH AS 6 TO 7 KFT AGL BY THE
AFTERNOON HOURS. GEOSTROPHIC FLOW IN THE REGION WILL REMAIN ELEVATED
WITH THE LOW HEIGHT ANOMALY OVER CENTRAL ONTARIO WHICH SUPPORTS
WIDESPREAD WESTERLY WIND GUSTS LATE TUESDAY MORNING/TUESDAY
AFTERNOON IN EXCESS OF 30 KNOTS. COMBINATION OF SHORTWAVE ENERGY
WORKING THROUGH THE TROUGH AXIS AND SPOKES OF ENHANCED MIDLEVEL
CONVERGENCE/SATURATION WILL BRING THE POTENTIAL FOR RAIN SHOWERS BY
TUESDAY MORNING. POTENTIAL MEDIUM IMPACT WEATHER SCENARIO MAY
UNFOLD...CONTINGENT ON OVERALL EFFICIENCY OF INDIVIDUAL CONVECTIVE
CIRCULATIONS OF THE SHOWERS TO ENHANCE DOWNWARD MOMENTUM TRANSPORT.
AFOREMENTIONED FORECAST DISCUSSION MADE REFERENCE TO A CLASSIC
INVERTED V STRUCTURE...WHICH SUGGESTS SOME POSSIBILITY THAT
WINDGUSTS COULD REACH 50 MPH. FUTURE SHIFTS CAN ASSESS THE
FEASIBILITY OF A POSSIBLE WIND ADVISORY FOR WEDNESDAY AFTERNOON.

PERSISTENT CYCLONIC FLOW AROUND UPPER LEVEL CLOSED LOW WILL BRING
ANOTHER DAY OF COLD AND SHOWERY TO SOUTHEASTERN MICHIGAN ON
WEDNESDAY. A SECONDARY SURGE OF COLD AIR ADVECTION IS FORECASTED
BETWEEN 15-18Z. THE CAA SHOULD WORK AGAINST DIURNAL HEATING...WITH
HIGHS SOME 7 TO 10 DEGREES COOLER THAN THE DAY BEFORE. HIGHS ON
WEDNESDAY ARE ONLY EXPECTED TO REACH THE MIDDLE TO UPPER 40S. BETTER
MESSAGE TO COMMUNICATE IS THAT WIND CHILLS FOR MANY AREAS WILL NOT
CLIMB OUT OF THE 30S.

THE REGION WILL STILL BE UNDER THE INFLUENCE OF LONGWAVE TROUGHING
ON THURSDAY BEFORE WEAK UPPER LEVEL RIDGING BUILDS IN FOR THE START
OF THE WEEKEND.  THIS TROUGH WILL CONTINUE TO LEAD TO COOLER TEMPS
THURSDAY BEFORE TEMPERATURES MODERATE A TINY BIT BACK INTO THE 50S
BY THE WEEKEND.  AT THIS POINT THE ONLY POTENTIAL FOR POSSIBLE
PRECIP IN THE EXTENDED WOULD BE ON SATURDAY...ALTHOUGH MOST MODELS
ARE KEEPING THE BULK OF THE PRECIP SOUTH OF THE CWA WITH THE
EXCEPTION OF THE 12Z ECMWF.

&&

.MARINE...

STRONG SOUTHWESTERLY WIND FIELD IS NOW IN PLACE WITH WINDSPEEDS AREA
WIDE RANGING BETWEEN 25 AND 35 KNOTS. SMALL CRAFT ADVISORIES REMAIN
IN EFFECT FOR ALL NEARSHORE ZONES. BREEZY WESTERLY WINDS WILL
PERSIST THROUGH MIDWEEK AS CONDITIONS REMAIN RELATIVELY STATIC WITH
LOW PRESSURE PARKED OVER THE GREAT LAKES. ADDITIONAL SMALL CRAFT
ADVISORIES FOR WIND WILL LIKELY BE NEEDED ON TUESDAY AND POSSIBLY
ONCE MORE ON WEDNESDAY.

&&

.AVIATION...ISSUED 118 PM EDT MON APR 20 2015

DISORGANIZED SHOWERS WORKING THROUGH SOUTHEAST MICHIGAN THIS
AFTERNOON AHEAD OF A COLD FRONT... WITH STILL LOW CHANCE OF ISOLATED
THUNDERSTORM DEVELOPING. WINDS WILL BE GUSTING BETWEEN 30 TO 40
KNOTS WITHIN ANY OF THE STRONGER SHOWERS. MVFR/LOW VFR CEILINGS
WILL HOLD INTO THE EARLY EVENING HOURS...AND STILL COULD BE
ISOLATED-SCATTERED LIGHT RAIN SHOWERS LEFT OVER...BUT WINDS
SHIFTING A BIT MORE SOUTHWEST-WEST BEHIND THE COLD FRONT WILL
ALLOW FOR A DRYING TREND. CLOUD COVER TONIGHT IS SOMEWHAT
UNCERTAIN AS COLD CYCLONIC FLOW OFF LAKE MICHIGAN MAY BE
SUFFICIENT TO MAINTAIN THE LOW VFR/BORDERLINE MVFR CEILINGS. IF
SKIES DO SCATTER OUT TONIGHT...HIGHER CONFIDENCE IN LOW VFR
CEILINGS REDEVELOPING TOMORROW MORNING...WITH POSSIBLY ENOUGH
INSTABILITY TO GENERATE SCATTERED SHOWERS DURING THE DAY. IT WILL
BE WINDY...ESPECIALLY UNDERNEATH ANY SHOWERS...AS WINDS COULD GUST
IN EXCESS OF 35 KNOTS.

FOR DTW...SHOWERS WILL BE CLEARING THE TERMINAL AT THE START OF THE
TAF PERIOD. THERE IS A CHANCE OF A COUPLE LIGHT RAIN SHOWERS EARLY
THIS EVENING...BUT AREA COVERAGE PRECLUDED THE MENTION.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CIGS AOB 5KFT THROUGH EARLY EARLY EVENING...THEN
  MEDIUM CONFIDENCE.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LHZ421-422-
     441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LEZ444.

&&

$$

SHORT TERM...SF
LONG TERM....CB/SS
MARINE.......CB
AVIATION.....SF


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).




000
FXUS63 KDTX 201946
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
346 PM EDT MON APR 20 2015

.SHORT TERM...TONIGHT

MUCAPES DID REACH 500 TO 800 J/KG EARLIER THIS AFTERNOON (PER LAPS
DATA)...WHICH WAS ABLE TO SUPPORT A COUPLE THUNDERSTORMS OVER
SOUTHEAST MICHIGAN. BULK OF CONVECTIVE ACTIVITY HAS PUSHED
EAST...AND CONTINUED DRYING BEHIND THE COLD FRONT WILL OCCUR...AS
SURFACE DEW PTS CRASH INTO THE 40S. WITH THAT COLDER/DRY AIR PUSH
IS SOME GUSTY WINDS...AS SOME PEAK WINDS OF 35 TO 45 MPH CAN BE
EXPECTED FOR ANOTHER COUPLE OF HOURS AS WE EXIT PEAK HEATING.
NOTED PEAK WIND AT DTW OF 42 KNOTS AT 1855Z. NAM/GFS MODEL
SOUNDINGS/LOW LEVEL RH FIELDS SUGGEST WE ARE GOING TO PARTIALLY
CLEAR OUT TONIGHT...BUT UPSTREAM OBSERVATIONS EXTENDING BACK WEST
OVER THE WESTERN GREAT LAKES/UPPER MISSISSIPPI RIVER VALLEY TO NOT
LOOK VERY ENCOURAGING...AND PREFERENCE WAS TO INCREASE THE CLOUD
COVER FORECAST FOR TONIGHT WITH THE COLD CYCLONIC FLOW. ALSO...AS
850 MB TEMPS FALL INTO THE MID NEGATIVE SINGLE NUMBERS OVER LAKE
MICHIGAN...SOME LAKE MICHIGAN MOISTURE/INSTABILITY CONTRIBUTION IS
NOT OUT OF THE QUESTION. HAVE CARRIED ISOLATED-SCATTERED LIGHT
RAIN SHOWER MENTION TO ACCOUNT FOR LINGERING ACTIVITY LATE THIS
AFTERNOON/EARLY THIS EVENING AND THEN THE POSSIBLE ACTIVITY TOWARD
MORNING. DESPITE CLOUDS...COLD ADVECTION EXPECTED TO SEND MINS
INTO THE UPPER 30S TO LOWER 40S.

&&

.LONG TERM...

A BROAD UPPER LEVEL TROUGH WITH A CLOSED LOW IN CLOSE PROXIMITY TO
THE GREAT LAKES REGION WILL KEEP SOUTHEASTERN MICHIGAN UNDER THE
INFLUENCE OF COLD CYCLONIC FLOW THROUGHOUT THE MIDWEEK PERIOD.
NATURE OF INDIVIDUAL SHORTWAVES ROTATING AROUND THIS UPPER LEVEL
FEATURE KEEPS THE SPECIFIC TIMING CONFIDENCE INHERENTLY LOW.

MAGNITUDE OF COLD AND DRY AIR ADVECTION FROM TONIGHT WILL
PRECONDITION THE ATMOSPHERE AND ALLOW FOR THE GROWTH OF A DEEP
DIURNAL NEAR SURFACE MIXED LAYER ON TUESDAY. FORECAST SOUNDINGS
SUGGEST MIXING HEIGHTS REACHING AS HIGH AS 6 TO 7 KFT AGL BY THE
AFTERNOON HOURS. GEOSTROPHIC FLOW IN THE REGION WILL REMAIN ELEVATED
WITH THE LOW HEIGHT ANOMALY OVER CENTRAL ONTARIO WHICH SUPPORTS
WIDESPREAD WESTERLY WIND GUSTS LATE TUESDAY MORNING/TUESDAY
AFTERNOON IN EXCESS OF 30 KNOTS. COMBINATION OF SHORTWAVE ENERGY
WORKING THROUGH THE TROUGH AXIS AND SPOKES OF ENHANCED MIDLEVEL
CONVERGENCE/SATURATION WILL BRING THE POTENTIAL FOR RAIN SHOWERS BY
TUESDAY MORNING. POTENTIAL MEDIUM IMPACT WEATHER SCENARIO MAY
UNFOLD...CONTINGENT ON OVERALL EFFICIENCY OF INDIVIDUAL CONVECTIVE
CIRCULATIONS OF THE SHOWERS TO ENHANCE DOWNWARD MOMENTUM TRANSPORT.
AFOREMENTIONED FORECAST DISCUSSION MADE REFERENCE TO A CLASSIC
INVERTED V STRUCTURE...WHICH SUGGESTS SOME POSSIBILITY THAT
WINDGUSTS COULD REACH 50 MPH. FUTURE SHIFTS CAN ASSESS THE
FEASIBILITY OF A POSSIBLE WIND ADVISORY FOR WEDNESDAY AFTERNOON.

PERSISTENT CYCLONIC FLOW AROUND UPPER LEVEL CLOSED LOW WILL BRING
ANOTHER DAY OF COLD AND SHOWERY TO SOUTHEASTERN MICHIGAN ON
WEDNESDAY. A SECONDARY SURGE OF COLD AIR ADVECTION IS FORECASTED
BETWEEN 15-18Z. THE CAA SHOULD WORK AGAINST DIURNAL HEATING...WITH
HIGHS SOME 7 TO 10 DEGREES COOLER THAN THE DAY BEFORE. HIGHS ON
WEDNESDAY ARE ONLY EXPECTED TO REACH THE MIDDLE TO UPPER 40S. BETTER
MESSAGE TO COMMUNICATE IS THAT WIND CHILLS FOR MANY AREAS WILL NOT
CLIMB OUT OF THE 30S.

THE REGION WILL STILL BE UNDER THE INFLUENCE OF LONGWAVE TROUGHING
ON THURSDAY BEFORE WEAK UPPER LEVEL RIDGING BUILDS IN FOR THE START
OF THE WEEKEND.  THIS TROUGH WILL CONTINUE TO LEAD TO COOLER TEMPS
THURSDAY BEFORE TEMPERATURES MODERATE A TINY BIT BACK INTO THE 50S
BY THE WEEKEND.  AT THIS POINT THE ONLY POTENTIAL FOR POSSIBLE
PRECIP IN THE EXTENDED WOULD BE ON SATURDAY...ALTHOUGH MOST MODELS
ARE KEEPING THE BULK OF THE PRECIP SOUTH OF THE CWA WITH THE
EXCEPTION OF THE 12Z ECMWF.

&&

.MARINE...

STRONG SOUTHWESTERLY WIND FIELD IS NOW IN PLACE WITH WINDSPEEDS AREA
WIDE RANGING BETWEEN 25 AND 35 KNOTS. SMALL CRAFT ADVISORIES REMAIN
IN EFFECT FOR ALL NEARSHORE ZONES. BREEZY WESTERLY WINDS WILL
PERSIST THROUGH MIDWEEK AS CONDITIONS REMAIN RELATIVELY STATIC WITH
LOW PRESSURE PARKED OVER THE GREAT LAKES. ADDITIONAL SMALL CRAFT
ADVISORIES FOR WIND WILL LIKELY BE NEEDED ON TUESDAY AND POSSIBLY
ONCE MORE ON WEDNESDAY.

&&

.AVIATION...ISSUED 118 PM EDT MON APR 20 2015

DISORGANIZED SHOWERS WORKING THROUGH SOUTHEAST MICHIGAN THIS
AFTERNOON AHEAD OF A COLD FRONT... WITH STILL LOW CHANCE OF ISOLATED
THUNDERSTORM DEVELOPING. WINDS WILL BE GUSTING BETWEEN 30 TO 40
KNOTS WITHIN ANY OF THE STRONGER SHOWERS. MVFR/LOW VFR CEILINGS
WILL HOLD INTO THE EARLY EVENING HOURS...AND STILL COULD BE
ISOLATED-SCATTERED LIGHT RAIN SHOWERS LEFT OVER...BUT WINDS
SHIFTING A BIT MORE SOUTHWEST-WEST BEHIND THE COLD FRONT WILL
ALLOW FOR A DRYING TREND. CLOUD COVER TONIGHT IS SOMEWHAT
UNCERTAIN AS COLD CYCLONIC FLOW OFF LAKE MICHIGAN MAY BE
SUFFICIENT TO MAINTAIN THE LOW VFR/BORDERLINE MVFR CEILINGS. IF
SKIES DO SCATTER OUT TONIGHT...HIGHER CONFIDENCE IN LOW VFR
CEILINGS REDEVELOPING TOMORROW MORNING...WITH POSSIBLY ENOUGH
INSTABILITY TO GENERATE SCATTERED SHOWERS DURING THE DAY. IT WILL
BE WINDY...ESPECIALLY UNDERNEATH ANY SHOWERS...AS WINDS COULD GUST
IN EXCESS OF 35 KNOTS.

FOR DTW...SHOWERS WILL BE CLEARING THE TERMINAL AT THE START OF THE
TAF PERIOD. THERE IS A CHANCE OF A COUPLE LIGHT RAIN SHOWERS EARLY
THIS EVENING...BUT AREA COVERAGE PRECLUDED THE MENTION.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CIGS AOB 5KFT THROUGH EARLY EARLY EVENING...THEN
  MEDIUM CONFIDENCE.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LHZ421-422-
     441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LEZ444.

&&

$$

SHORT TERM...SF
LONG TERM....CB/SS
MARINE.......CB
AVIATION.....SF


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).




000
FXUS63 KMQT 201939
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
339 PM EDT MON APR 20 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT MON APR 20 2015

UPPER AIR PATTERN CONSISTS OF A ELONGATED 500 MB TROUGH WITH SEVERAL
SHORTWAVES EMBEDDED IN IT. THE SHORTWAVE OVER LOWER MICHIGAN WILL BE
SPREADING PCPN UP INTO THE CWA THIS MORNING WHILE ANOTHER SHORTWAVE
OVER THE RED RIVER VALLEY OF THE NORTH WILL PUT PCPN IN OVER THE FAR
WEST THIS MORNING. BOTH THESE SHORTWAVES WILL COMBINE OVER THE AREA
AND CAUSE SOME WIDESPREAD PCPN THIS MORNING OVER THE CWA. UPPER
TROUGH SLOWLY MOVES EAST WITH A 500 MB LOW MOVING OVER THE U.P. LATE
TONIGHT. NAM SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE OVER THE CWA THIS MORNING. THE DEEPER MOISTURE REMAIN
OVER THE AREA THROUGH TONIGHT WHILE THE Q-VECTOR CONVERGENCE WEAKENS
AND MOVES OUT BY THIS EVENING BEFORE MOVING BACK IN LATE TONIGHT
WITH THE 500 MB LOW. GFS AND ECMWF SHOW ABOUT THE SAME THING AS
WELL.

HAD TO HANG ONTO THE DRIER AIR ACROSS THE CENTRAL CWA A BIT LONGER
THIS MORNING AND CUT THE QPF AMOUNTS BECAUSE OF THIS. DID GO WITH A
COMBO OF WET BULB HEIGHTS AND WARM TEMPERATURES ALOFT TO DETERMINE
SNOW FOR THIS FORECAST AND LOOKS LIKE THE ACCUMULATING SNOW WILL BE
TONIGHT WHERE UP TO 2 INCHES COULD FALL ACROSS THE WESTERN
HIGHLANDS. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
TEMPERATURE FORECAST AND WENT WITH CATEGORICAL POPS FOR TODAY FOR
THE CWA AND THEN LIKELY POPS IN NORTHWEST LAKE EFFECT BELTS TONIGHT
AND KEPT SOME SLIGHT CHANCE POPS IN THE FAR SOUTH DUE TO THE UPPER
LOW MOVING INTO THE AREA AND WRAPAROUND PCPN IN THE AREA.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 PM EDT MON APR 20 2015

A LARGE UPPER LOW CENTERED OVER NORTHERN ONTARIO WILL BE
INFLUENCING THE GREAT LAKES REGION THROUGH THE FIRST HALF OF THE
LONG TERM PERIOD. THIS WILL LEAD TO BELOW NORMAL TEMPERATURES AND
PERIODS OF SNOW BEFORE GRADUALLY SHIFTING EAST INTO THE ATLANTIC BY
THE WEEKEND.

AS THAT UPPER LOW SPINS BETWEEN LAKE SUPERIOR AND JAMES BAY...IT
WILL ROTATE SEVERAL SHORTWAVES ACROSS THE UPPER GREAT LAKES REGION
TUESDAY NIGHT THROUGH THURSDAY. THESE WAVES WILL BRING PERIODS OF
SHOWERS TO THE AREA...WITH HELP FROM BOTH LAKE SUPERIOR (850MB
TEMPS FALLING TO -10C TO -12C ON WEDNESDAY MORNING) AND TERRAIN
ENHANCEMENT (PERSISTENT LOW LEVEL NORTHWESTERLY FLOW). WILL CONTINUE
TO FOCUS THE HIGHEST POPS (LIKELY VALUES) IN THOSE AREAS FAVORED BY
ALL THREE FEATURES (HIGHER TERRAIN OF THE WEST/NORTHWEST) AND ALSO
EAST DOWNWIND OF LAKE SUPERIOR...AND INCLUDE CHANCE/SLIGHTS FOR THE
REST OF THE CWA. WITH THE AMOUNT OF COLD AIR IN PLACE...EXPECT THE
PRECIPITATION TO FALL MAINLY AS SNOW. WITH LOW LEVEL TEMPERATURES
WARMING AWAY OVER THE SOUTHERN THIRD OF THE CWA...COULD SEE SOME
RAIN MIXING IN THERE...BUT OTHERWISE SNOW WILL BE THE NORM. COULD
SEE A COUPLE INCHES OF ACCUMULATION IN THE FAVORED LOCATIONS
TUESDAY NIGHT AND UP TO AN INCH WEDNESDAY AND AGAIN WEDNESDAY
NIGHT. WITH DRIER AIR STARTING TO MOVE INTO THE AREA ON
THURSDAY (ASSOCIATED WITH A SURFACE RIDGE MOVING INTO THE
NORTHERN PLAINS...SHOULD SEE THE COVERAGE OF THE SHOWERS
DIMINISHING THROUGH THE DAY THURSDAY AND CONTINUING TO WEAKENING
INTO FRIDAY. ALSO...DON/T EXPECT HIGHS TO RISE MUCH OUT OF THE
LOW-MID 30S ON WED/THURS OVER THE NORTH HALF OF THE CWA...WITH SOME
HIGHS AROUND 40 OVER THE SOUTH CENTRAL. WILL LIKELY BREAK THE
RECORD LOW HIGH TEMPERATURE HERE AT OUR OFFICE ON WEDNESDAY (36 SET
IN 1972).

EXTENDED RANGE MODELS DIFFER ON HOW QUICKLY THE UPPER LOW DEPARTS
THIS WEEKEND...BUT SHOULD STILL SEE ENOUGH INFLUENCE FROM THE
SURFACE RIDGE MOVING INTO THE NORTHERN PLAINS TO KEEP MOST OF THE
AREA DRY. WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR...EXPECT
TEMPERATURES TO REMAIN BELOW NORMAL BUT IN THE 40S TO AROUND 50. AS
THE UPPER LOW RETROGRADES BACK OVER QUEBEC EARLY NEXT WEEK...COULD
SEE THE UPPER GREAT LAKES REGION BEING AFFECTED BY THE WESTERN EDGE
OF THE ENERGY ROTATING AROUND THE UPPER LOW AND LIKELY KEEPING
BELOW NORMAL TEMPERATURES IN PLACE THROUGH THE END OF APRIL.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 131 PM EDT MON APR 20 2015

AREA OF DEEPER MSTR ASSOCIATED WITH BAND OF SHARPER FORCING WL BRING
A PERIOD OF STEADY SN TO CMX THRU THIS AFTN ALONG WITH LIFR
CONDITIONS. GUSTY W WINDS TO NEAR 30 KTS WL ALSO IMPACT THIS MORE
EXPOSED LOCATION. THE AREA OF PCPN WL EXIT IWD SOON AFTER TAF
ISSUANCE...SO EXPECT AN IMPROVEMENT THERE FM IFR TO MVFR WITH THE
ARRIVAL OF SOME DRIER AIR/SUBSIDENCE. SINCE THE BAND OF HEAVIER PCPN
IS LIKELY TO REMAIN TO THE W OF SAW...THERE SHOULD BE MVFR CIGS WITH
ONLY SOME OCNL -SHRA IN THE PRESENCE OF A DOWNSLOPE WIND COMPONENT.
FOR THIS EVNG...MVFR CONDITIONS SHOULD BE THE RULE WITH MVFR CIGS
AND ONLY SOME SCT LIGHT -SHSN OR -SHSNRA. BUT THE APRCH OF ANOTHER
DISTURBANCE/LO PRES TROF LATE TNGT SHOULD RESULT IN DETERIORATING
CONDITIONS AGAIN WITH IFR CONDITIONS DVLPG AT IWD AND CMX. DOWNSLOPE
WINDS AT SAW WL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO IWD AND CMX BY LATE MRNG ON TUE.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT MON APR 20 2015

AS A LOW LIFTS THROUGH THE SOO THIS AFTERNOON...WINDS WILL BACK TO
THE WEST-NORTHWEST THIS AFTERNOON. WITH THE LOW BECOMING STATIONARY
JUST TO THE SOUTHWEST OF JAMES BAY TONIGHT THROUGH
WEDNESDAY...PERSISTENT NORTHWESTERLY WINDS OF 20-30KTS ARE EXPECTED.
ALTHOUGH THE LOW WILL WEAKEN AND MOVE EAST ACROSS QUEBEC WEDNESDAY
NIGHT INTO THURSDAY...THE NORTHWEST WINDS UP TO 25KTS WILL PERSIST
AS A RIDGE MOVES INTO THE NORTHERN PLAINS. THE WINDS DIMINISH THEN
BELOW 20 KNOTS BY THURSDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...SRF
AVIATION...KC
MARINE...07



000
FXUS63 KMQT 201939
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
339 PM EDT MON APR 20 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT MON APR 20 2015

UPPER AIR PATTERN CONSISTS OF A ELONGATED 500 MB TROUGH WITH SEVERAL
SHORTWAVES EMBEDDED IN IT. THE SHORTWAVE OVER LOWER MICHIGAN WILL BE
SPREADING PCPN UP INTO THE CWA THIS MORNING WHILE ANOTHER SHORTWAVE
OVER THE RED RIVER VALLEY OF THE NORTH WILL PUT PCPN IN OVER THE FAR
WEST THIS MORNING. BOTH THESE SHORTWAVES WILL COMBINE OVER THE AREA
AND CAUSE SOME WIDESPREAD PCPN THIS MORNING OVER THE CWA. UPPER
TROUGH SLOWLY MOVES EAST WITH A 500 MB LOW MOVING OVER THE U.P. LATE
TONIGHT. NAM SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE OVER THE CWA THIS MORNING. THE DEEPER MOISTURE REMAIN
OVER THE AREA THROUGH TONIGHT WHILE THE Q-VECTOR CONVERGENCE WEAKENS
AND MOVES OUT BY THIS EVENING BEFORE MOVING BACK IN LATE TONIGHT
WITH THE 500 MB LOW. GFS AND ECMWF SHOW ABOUT THE SAME THING AS
WELL.

HAD TO HANG ONTO THE DRIER AIR ACROSS THE CENTRAL CWA A BIT LONGER
THIS MORNING AND CUT THE QPF AMOUNTS BECAUSE OF THIS. DID GO WITH A
COMBO OF WET BULB HEIGHTS AND WARM TEMPERATURES ALOFT TO DETERMINE
SNOW FOR THIS FORECAST AND LOOKS LIKE THE ACCUMULATING SNOW WILL BE
TONIGHT WHERE UP TO 2 INCHES COULD FALL ACROSS THE WESTERN
HIGHLANDS. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
TEMPERATURE FORECAST AND WENT WITH CATEGORICAL POPS FOR TODAY FOR
THE CWA AND THEN LIKELY POPS IN NORTHWEST LAKE EFFECT BELTS TONIGHT
AND KEPT SOME SLIGHT CHANCE POPS IN THE FAR SOUTH DUE TO THE UPPER
LOW MOVING INTO THE AREA AND WRAPAROUND PCPN IN THE AREA.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 PM EDT MON APR 20 2015

A LARGE UPPER LOW CENTERED OVER NORTHERN ONTARIO WILL BE
INFLUENCING THE GREAT LAKES REGION THROUGH THE FIRST HALF OF THE
LONG TERM PERIOD. THIS WILL LEAD TO BELOW NORMAL TEMPERATURES AND
PERIODS OF SNOW BEFORE GRADUALLY SHIFTING EAST INTO THE ATLANTIC BY
THE WEEKEND.

AS THAT UPPER LOW SPINS BETWEEN LAKE SUPERIOR AND JAMES BAY...IT
WILL ROTATE SEVERAL SHORTWAVES ACROSS THE UPPER GREAT LAKES REGION
TUESDAY NIGHT THROUGH THURSDAY. THESE WAVES WILL BRING PERIODS OF
SHOWERS TO THE AREA...WITH HELP FROM BOTH LAKE SUPERIOR (850MB
TEMPS FALLING TO -10C TO -12C ON WEDNESDAY MORNING) AND TERRAIN
ENHANCEMENT (PERSISTENT LOW LEVEL NORTHWESTERLY FLOW). WILL CONTINUE
TO FOCUS THE HIGHEST POPS (LIKELY VALUES) IN THOSE AREAS FAVORED BY
ALL THREE FEATURES (HIGHER TERRAIN OF THE WEST/NORTHWEST) AND ALSO
EAST DOWNWIND OF LAKE SUPERIOR...AND INCLUDE CHANCE/SLIGHTS FOR THE
REST OF THE CWA. WITH THE AMOUNT OF COLD AIR IN PLACE...EXPECT THE
PRECIPITATION TO FALL MAINLY AS SNOW. WITH LOW LEVEL TEMPERATURES
WARMING AWAY OVER THE SOUTHERN THIRD OF THE CWA...COULD SEE SOME
RAIN MIXING IN THERE...BUT OTHERWISE SNOW WILL BE THE NORM. COULD
SEE A COUPLE INCHES OF ACCUMULATION IN THE FAVORED LOCATIONS
TUESDAY NIGHT AND UP TO AN INCH WEDNESDAY AND AGAIN WEDNESDAY
NIGHT. WITH DRIER AIR STARTING TO MOVE INTO THE AREA ON
THURSDAY (ASSOCIATED WITH A SURFACE RIDGE MOVING INTO THE
NORTHERN PLAINS...SHOULD SEE THE COVERAGE OF THE SHOWERS
DIMINISHING THROUGH THE DAY THURSDAY AND CONTINUING TO WEAKENING
INTO FRIDAY. ALSO...DON/T EXPECT HIGHS TO RISE MUCH OUT OF THE
LOW-MID 30S ON WED/THURS OVER THE NORTH HALF OF THE CWA...WITH SOME
HIGHS AROUND 40 OVER THE SOUTH CENTRAL. WILL LIKELY BREAK THE
RECORD LOW HIGH TEMPERATURE HERE AT OUR OFFICE ON WEDNESDAY (36 SET
IN 1972).

EXTENDED RANGE MODELS DIFFER ON HOW QUICKLY THE UPPER LOW DEPARTS
THIS WEEKEND...BUT SHOULD STILL SEE ENOUGH INFLUENCE FROM THE
SURFACE RIDGE MOVING INTO THE NORTHERN PLAINS TO KEEP MOST OF THE
AREA DRY. WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR...EXPECT
TEMPERATURES TO REMAIN BELOW NORMAL BUT IN THE 40S TO AROUND 50. AS
THE UPPER LOW RETROGRADES BACK OVER QUEBEC EARLY NEXT WEEK...COULD
SEE THE UPPER GREAT LAKES REGION BEING AFFECTED BY THE WESTERN EDGE
OF THE ENERGY ROTATING AROUND THE UPPER LOW AND LIKELY KEEPING
BELOW NORMAL TEMPERATURES IN PLACE THROUGH THE END OF APRIL.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 131 PM EDT MON APR 20 2015

AREA OF DEEPER MSTR ASSOCIATED WITH BAND OF SHARPER FORCING WL BRING
A PERIOD OF STEADY SN TO CMX THRU THIS AFTN ALONG WITH LIFR
CONDITIONS. GUSTY W WINDS TO NEAR 30 KTS WL ALSO IMPACT THIS MORE
EXPOSED LOCATION. THE AREA OF PCPN WL EXIT IWD SOON AFTER TAF
ISSUANCE...SO EXPECT AN IMPROVEMENT THERE FM IFR TO MVFR WITH THE
ARRIVAL OF SOME DRIER AIR/SUBSIDENCE. SINCE THE BAND OF HEAVIER PCPN
IS LIKELY TO REMAIN TO THE W OF SAW...THERE SHOULD BE MVFR CIGS WITH
ONLY SOME OCNL -SHRA IN THE PRESENCE OF A DOWNSLOPE WIND COMPONENT.
FOR THIS EVNG...MVFR CONDITIONS SHOULD BE THE RULE WITH MVFR CIGS
AND ONLY SOME SCT LIGHT -SHSN OR -SHSNRA. BUT THE APRCH OF ANOTHER
DISTURBANCE/LO PRES TROF LATE TNGT SHOULD RESULT IN DETERIORATING
CONDITIONS AGAIN WITH IFR CONDITIONS DVLPG AT IWD AND CMX. DOWNSLOPE
WINDS AT SAW WL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO IWD AND CMX BY LATE MRNG ON TUE.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT MON APR 20 2015

AS A LOW LIFTS THROUGH THE SOO THIS AFTERNOON...WINDS WILL BACK TO
THE WEST-NORTHWEST THIS AFTERNOON. WITH THE LOW BECOMING STATIONARY
JUST TO THE SOUTHWEST OF JAMES BAY TONIGHT THROUGH
WEDNESDAY...PERSISTENT NORTHWESTERLY WINDS OF 20-30KTS ARE EXPECTED.
ALTHOUGH THE LOW WILL WEAKEN AND MOVE EAST ACROSS QUEBEC WEDNESDAY
NIGHT INTO THURSDAY...THE NORTHWEST WINDS UP TO 25KTS WILL PERSIST
AS A RIDGE MOVES INTO THE NORTHERN PLAINS. THE WINDS DIMINISH THEN
BELOW 20 KNOTS BY THURSDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...SRF
AVIATION...KC
MARINE...07



000
FXUS63 KMQT 201939
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
339 PM EDT MON APR 20 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT MON APR 20 2015

UPPER AIR PATTERN CONSISTS OF A ELONGATED 500 MB TROUGH WITH SEVERAL
SHORTWAVES EMBEDDED IN IT. THE SHORTWAVE OVER LOWER MICHIGAN WILL BE
SPREADING PCPN UP INTO THE CWA THIS MORNING WHILE ANOTHER SHORTWAVE
OVER THE RED RIVER VALLEY OF THE NORTH WILL PUT PCPN IN OVER THE FAR
WEST THIS MORNING. BOTH THESE SHORTWAVES WILL COMBINE OVER THE AREA
AND CAUSE SOME WIDESPREAD PCPN THIS MORNING OVER THE CWA. UPPER
TROUGH SLOWLY MOVES EAST WITH A 500 MB LOW MOVING OVER THE U.P. LATE
TONIGHT. NAM SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE OVER THE CWA THIS MORNING. THE DEEPER MOISTURE REMAIN
OVER THE AREA THROUGH TONIGHT WHILE THE Q-VECTOR CONVERGENCE WEAKENS
AND MOVES OUT BY THIS EVENING BEFORE MOVING BACK IN LATE TONIGHT
WITH THE 500 MB LOW. GFS AND ECMWF SHOW ABOUT THE SAME THING AS
WELL.

HAD TO HANG ONTO THE DRIER AIR ACROSS THE CENTRAL CWA A BIT LONGER
THIS MORNING AND CUT THE QPF AMOUNTS BECAUSE OF THIS. DID GO WITH A
COMBO OF WET BULB HEIGHTS AND WARM TEMPERATURES ALOFT TO DETERMINE
SNOW FOR THIS FORECAST AND LOOKS LIKE THE ACCUMULATING SNOW WILL BE
TONIGHT WHERE UP TO 2 INCHES COULD FALL ACROSS THE WESTERN
HIGHLANDS. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
TEMPERATURE FORECAST AND WENT WITH CATEGORICAL POPS FOR TODAY FOR
THE CWA AND THEN LIKELY POPS IN NORTHWEST LAKE EFFECT BELTS TONIGHT
AND KEPT SOME SLIGHT CHANCE POPS IN THE FAR SOUTH DUE TO THE UPPER
LOW MOVING INTO THE AREA AND WRAPAROUND PCPN IN THE AREA.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 PM EDT MON APR 20 2015

A LARGE UPPER LOW CENTERED OVER NORTHERN ONTARIO WILL BE
INFLUENCING THE GREAT LAKES REGION THROUGH THE FIRST HALF OF THE
LONG TERM PERIOD. THIS WILL LEAD TO BELOW NORMAL TEMPERATURES AND
PERIODS OF SNOW BEFORE GRADUALLY SHIFTING EAST INTO THE ATLANTIC BY
THE WEEKEND.

AS THAT UPPER LOW SPINS BETWEEN LAKE SUPERIOR AND JAMES BAY...IT
WILL ROTATE SEVERAL SHORTWAVES ACROSS THE UPPER GREAT LAKES REGION
TUESDAY NIGHT THROUGH THURSDAY. THESE WAVES WILL BRING PERIODS OF
SHOWERS TO THE AREA...WITH HELP FROM BOTH LAKE SUPERIOR (850MB
TEMPS FALLING TO -10C TO -12C ON WEDNESDAY MORNING) AND TERRAIN
ENHANCEMENT (PERSISTENT LOW LEVEL NORTHWESTERLY FLOW). WILL CONTINUE
TO FOCUS THE HIGHEST POPS (LIKELY VALUES) IN THOSE AREAS FAVORED BY
ALL THREE FEATURES (HIGHER TERRAIN OF THE WEST/NORTHWEST) AND ALSO
EAST DOWNWIND OF LAKE SUPERIOR...AND INCLUDE CHANCE/SLIGHTS FOR THE
REST OF THE CWA. WITH THE AMOUNT OF COLD AIR IN PLACE...EXPECT THE
PRECIPITATION TO FALL MAINLY AS SNOW. WITH LOW LEVEL TEMPERATURES
WARMING AWAY OVER THE SOUTHERN THIRD OF THE CWA...COULD SEE SOME
RAIN MIXING IN THERE...BUT OTHERWISE SNOW WILL BE THE NORM. COULD
SEE A COUPLE INCHES OF ACCUMULATION IN THE FAVORED LOCATIONS
TUESDAY NIGHT AND UP TO AN INCH WEDNESDAY AND AGAIN WEDNESDAY
NIGHT. WITH DRIER AIR STARTING TO MOVE INTO THE AREA ON
THURSDAY (ASSOCIATED WITH A SURFACE RIDGE MOVING INTO THE
NORTHERN PLAINS...SHOULD SEE THE COVERAGE OF THE SHOWERS
DIMINISHING THROUGH THE DAY THURSDAY AND CONTINUING TO WEAKENING
INTO FRIDAY. ALSO...DON/T EXPECT HIGHS TO RISE MUCH OUT OF THE
LOW-MID 30S ON WED/THURS OVER THE NORTH HALF OF THE CWA...WITH SOME
HIGHS AROUND 40 OVER THE SOUTH CENTRAL. WILL LIKELY BREAK THE
RECORD LOW HIGH TEMPERATURE HERE AT OUR OFFICE ON WEDNESDAY (36 SET
IN 1972).

EXTENDED RANGE MODELS DIFFER ON HOW QUICKLY THE UPPER LOW DEPARTS
THIS WEEKEND...BUT SHOULD STILL SEE ENOUGH INFLUENCE FROM THE
SURFACE RIDGE MOVING INTO THE NORTHERN PLAINS TO KEEP MOST OF THE
AREA DRY. WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR...EXPECT
TEMPERATURES TO REMAIN BELOW NORMAL BUT IN THE 40S TO AROUND 50. AS
THE UPPER LOW RETROGRADES BACK OVER QUEBEC EARLY NEXT WEEK...COULD
SEE THE UPPER GREAT LAKES REGION BEING AFFECTED BY THE WESTERN EDGE
OF THE ENERGY ROTATING AROUND THE UPPER LOW AND LIKELY KEEPING
BELOW NORMAL TEMPERATURES IN PLACE THROUGH THE END OF APRIL.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 131 PM EDT MON APR 20 2015

AREA OF DEEPER MSTR ASSOCIATED WITH BAND OF SHARPER FORCING WL BRING
A PERIOD OF STEADY SN TO CMX THRU THIS AFTN ALONG WITH LIFR
CONDITIONS. GUSTY W WINDS TO NEAR 30 KTS WL ALSO IMPACT THIS MORE
EXPOSED LOCATION. THE AREA OF PCPN WL EXIT IWD SOON AFTER TAF
ISSUANCE...SO EXPECT AN IMPROVEMENT THERE FM IFR TO MVFR WITH THE
ARRIVAL OF SOME DRIER AIR/SUBSIDENCE. SINCE THE BAND OF HEAVIER PCPN
IS LIKELY TO REMAIN TO THE W OF SAW...THERE SHOULD BE MVFR CIGS WITH
ONLY SOME OCNL -SHRA IN THE PRESENCE OF A DOWNSLOPE WIND COMPONENT.
FOR THIS EVNG...MVFR CONDITIONS SHOULD BE THE RULE WITH MVFR CIGS
AND ONLY SOME SCT LIGHT -SHSN OR -SHSNRA. BUT THE APRCH OF ANOTHER
DISTURBANCE/LO PRES TROF LATE TNGT SHOULD RESULT IN DETERIORATING
CONDITIONS AGAIN WITH IFR CONDITIONS DVLPG AT IWD AND CMX. DOWNSLOPE
WINDS AT SAW WL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO IWD AND CMX BY LATE MRNG ON TUE.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT MON APR 20 2015

AS A LOW LIFTS THROUGH THE SOO THIS AFTERNOON...WINDS WILL BACK TO
THE WEST-NORTHWEST THIS AFTERNOON. WITH THE LOW BECOMING STATIONARY
JUST TO THE SOUTHWEST OF JAMES BAY TONIGHT THROUGH
WEDNESDAY...PERSISTENT NORTHWESTERLY WINDS OF 20-30KTS ARE EXPECTED.
ALTHOUGH THE LOW WILL WEAKEN AND MOVE EAST ACROSS QUEBEC WEDNESDAY
NIGHT INTO THURSDAY...THE NORTHWEST WINDS UP TO 25KTS WILL PERSIST
AS A RIDGE MOVES INTO THE NORTHERN PLAINS. THE WINDS DIMINISH THEN
BELOW 20 KNOTS BY THURSDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...SRF
AVIATION...KC
MARINE...07




000
FXUS63 KMQT 201939
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
339 PM EDT MON APR 20 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT MON APR 20 2015

UPPER AIR PATTERN CONSISTS OF A ELONGATED 500 MB TROUGH WITH SEVERAL
SHORTWAVES EMBEDDED IN IT. THE SHORTWAVE OVER LOWER MICHIGAN WILL BE
SPREADING PCPN UP INTO THE CWA THIS MORNING WHILE ANOTHER SHORTWAVE
OVER THE RED RIVER VALLEY OF THE NORTH WILL PUT PCPN IN OVER THE FAR
WEST THIS MORNING. BOTH THESE SHORTWAVES WILL COMBINE OVER THE AREA
AND CAUSE SOME WIDESPREAD PCPN THIS MORNING OVER THE CWA. UPPER
TROUGH SLOWLY MOVES EAST WITH A 500 MB LOW MOVING OVER THE U.P. LATE
TONIGHT. NAM SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE OVER THE CWA THIS MORNING. THE DEEPER MOISTURE REMAIN
OVER THE AREA THROUGH TONIGHT WHILE THE Q-VECTOR CONVERGENCE WEAKENS
AND MOVES OUT BY THIS EVENING BEFORE MOVING BACK IN LATE TONIGHT
WITH THE 500 MB LOW. GFS AND ECMWF SHOW ABOUT THE SAME THING AS
WELL.

HAD TO HANG ONTO THE DRIER AIR ACROSS THE CENTRAL CWA A BIT LONGER
THIS MORNING AND CUT THE QPF AMOUNTS BECAUSE OF THIS. DID GO WITH A
COMBO OF WET BULB HEIGHTS AND WARM TEMPERATURES ALOFT TO DETERMINE
SNOW FOR THIS FORECAST AND LOOKS LIKE THE ACCUMULATING SNOW WILL BE
TONIGHT WHERE UP TO 2 INCHES COULD FALL ACROSS THE WESTERN
HIGHLANDS. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
TEMPERATURE FORECAST AND WENT WITH CATEGORICAL POPS FOR TODAY FOR
THE CWA AND THEN LIKELY POPS IN NORTHWEST LAKE EFFECT BELTS TONIGHT
AND KEPT SOME SLIGHT CHANCE POPS IN THE FAR SOUTH DUE TO THE UPPER
LOW MOVING INTO THE AREA AND WRAPAROUND PCPN IN THE AREA.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 PM EDT MON APR 20 2015

A LARGE UPPER LOW CENTERED OVER NORTHERN ONTARIO WILL BE
INFLUENCING THE GREAT LAKES REGION THROUGH THE FIRST HALF OF THE
LONG TERM PERIOD. THIS WILL LEAD TO BELOW NORMAL TEMPERATURES AND
PERIODS OF SNOW BEFORE GRADUALLY SHIFTING EAST INTO THE ATLANTIC BY
THE WEEKEND.

AS THAT UPPER LOW SPINS BETWEEN LAKE SUPERIOR AND JAMES BAY...IT
WILL ROTATE SEVERAL SHORTWAVES ACROSS THE UPPER GREAT LAKES REGION
TUESDAY NIGHT THROUGH THURSDAY. THESE WAVES WILL BRING PERIODS OF
SHOWERS TO THE AREA...WITH HELP FROM BOTH LAKE SUPERIOR (850MB
TEMPS FALLING TO -10C TO -12C ON WEDNESDAY MORNING) AND TERRAIN
ENHANCEMENT (PERSISTENT LOW LEVEL NORTHWESTERLY FLOW). WILL CONTINUE
TO FOCUS THE HIGHEST POPS (LIKELY VALUES) IN THOSE AREAS FAVORED BY
ALL THREE FEATURES (HIGHER TERRAIN OF THE WEST/NORTHWEST) AND ALSO
EAST DOWNWIND OF LAKE SUPERIOR...AND INCLUDE CHANCE/SLIGHTS FOR THE
REST OF THE CWA. WITH THE AMOUNT OF COLD AIR IN PLACE...EXPECT THE
PRECIPITATION TO FALL MAINLY AS SNOW. WITH LOW LEVEL TEMPERATURES
WARMING AWAY OVER THE SOUTHERN THIRD OF THE CWA...COULD SEE SOME
RAIN MIXING IN THERE...BUT OTHERWISE SNOW WILL BE THE NORM. COULD
SEE A COUPLE INCHES OF ACCUMULATION IN THE FAVORED LOCATIONS
TUESDAY NIGHT AND UP TO AN INCH WEDNESDAY AND AGAIN WEDNESDAY
NIGHT. WITH DRIER AIR STARTING TO MOVE INTO THE AREA ON
THURSDAY (ASSOCIATED WITH A SURFACE RIDGE MOVING INTO THE
NORTHERN PLAINS...SHOULD SEE THE COVERAGE OF THE SHOWERS
DIMINISHING THROUGH THE DAY THURSDAY AND CONTINUING TO WEAKENING
INTO FRIDAY. ALSO...DON/T EXPECT HIGHS TO RISE MUCH OUT OF THE
LOW-MID 30S ON WED/THURS OVER THE NORTH HALF OF THE CWA...WITH SOME
HIGHS AROUND 40 OVER THE SOUTH CENTRAL. WILL LIKELY BREAK THE
RECORD LOW HIGH TEMPERATURE HERE AT OUR OFFICE ON WEDNESDAY (36 SET
IN 1972).

EXTENDED RANGE MODELS DIFFER ON HOW QUICKLY THE UPPER LOW DEPARTS
THIS WEEKEND...BUT SHOULD STILL SEE ENOUGH INFLUENCE FROM THE
SURFACE RIDGE MOVING INTO THE NORTHERN PLAINS TO KEEP MOST OF THE
AREA DRY. WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR...EXPECT
TEMPERATURES TO REMAIN BELOW NORMAL BUT IN THE 40S TO AROUND 50. AS
THE UPPER LOW RETROGRADES BACK OVER QUEBEC EARLY NEXT WEEK...COULD
SEE THE UPPER GREAT LAKES REGION BEING AFFECTED BY THE WESTERN EDGE
OF THE ENERGY ROTATING AROUND THE UPPER LOW AND LIKELY KEEPING
BELOW NORMAL TEMPERATURES IN PLACE THROUGH THE END OF APRIL.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 131 PM EDT MON APR 20 2015

AREA OF DEEPER MSTR ASSOCIATED WITH BAND OF SHARPER FORCING WL BRING
A PERIOD OF STEADY SN TO CMX THRU THIS AFTN ALONG WITH LIFR
CONDITIONS. GUSTY W WINDS TO NEAR 30 KTS WL ALSO IMPACT THIS MORE
EXPOSED LOCATION. THE AREA OF PCPN WL EXIT IWD SOON AFTER TAF
ISSUANCE...SO EXPECT AN IMPROVEMENT THERE FM IFR TO MVFR WITH THE
ARRIVAL OF SOME DRIER AIR/SUBSIDENCE. SINCE THE BAND OF HEAVIER PCPN
IS LIKELY TO REMAIN TO THE W OF SAW...THERE SHOULD BE MVFR CIGS WITH
ONLY SOME OCNL -SHRA IN THE PRESENCE OF A DOWNSLOPE WIND COMPONENT.
FOR THIS EVNG...MVFR CONDITIONS SHOULD BE THE RULE WITH MVFR CIGS
AND ONLY SOME SCT LIGHT -SHSN OR -SHSNRA. BUT THE APRCH OF ANOTHER
DISTURBANCE/LO PRES TROF LATE TNGT SHOULD RESULT IN DETERIORATING
CONDITIONS AGAIN WITH IFR CONDITIONS DVLPG AT IWD AND CMX. DOWNSLOPE
WINDS AT SAW WL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO IWD AND CMX BY LATE MRNG ON TUE.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT MON APR 20 2015

AS A LOW LIFTS THROUGH THE SOO THIS AFTERNOON...WINDS WILL BACK TO
THE WEST-NORTHWEST THIS AFTERNOON. WITH THE LOW BECOMING STATIONARY
JUST TO THE SOUTHWEST OF JAMES BAY TONIGHT THROUGH
WEDNESDAY...PERSISTENT NORTHWESTERLY WINDS OF 20-30KTS ARE EXPECTED.
ALTHOUGH THE LOW WILL WEAKEN AND MOVE EAST ACROSS QUEBEC WEDNESDAY
NIGHT INTO THURSDAY...THE NORTHWEST WINDS UP TO 25KTS WILL PERSIST
AS A RIDGE MOVES INTO THE NORTHERN PLAINS. THE WINDS DIMINISH THEN
BELOW 20 KNOTS BY THURSDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...SRF
AVIATION...KC
MARINE...07




000
FXUS63 KMQT 201939
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
339 PM EDT MON APR 20 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT MON APR 20 2015

UPPER AIR PATTERN CONSISTS OF A ELONGATED 500 MB TROUGH WITH SEVERAL
SHORTWAVES EMBEDDED IN IT. THE SHORTWAVE OVER LOWER MICHIGAN WILL BE
SPREADING PCPN UP INTO THE CWA THIS MORNING WHILE ANOTHER SHORTWAVE
OVER THE RED RIVER VALLEY OF THE NORTH WILL PUT PCPN IN OVER THE FAR
WEST THIS MORNING. BOTH THESE SHORTWAVES WILL COMBINE OVER THE AREA
AND CAUSE SOME WIDESPREAD PCPN THIS MORNING OVER THE CWA. UPPER
TROUGH SLOWLY MOVES EAST WITH A 500 MB LOW MOVING OVER THE U.P. LATE
TONIGHT. NAM SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE OVER THE CWA THIS MORNING. THE DEEPER MOISTURE REMAIN
OVER THE AREA THROUGH TONIGHT WHILE THE Q-VECTOR CONVERGENCE WEAKENS
AND MOVES OUT BY THIS EVENING BEFORE MOVING BACK IN LATE TONIGHT
WITH THE 500 MB LOW. GFS AND ECMWF SHOW ABOUT THE SAME THING AS
WELL.

HAD TO HANG ONTO THE DRIER AIR ACROSS THE CENTRAL CWA A BIT LONGER
THIS MORNING AND CUT THE QPF AMOUNTS BECAUSE OF THIS. DID GO WITH A
COMBO OF WET BULB HEIGHTS AND WARM TEMPERATURES ALOFT TO DETERMINE
SNOW FOR THIS FORECAST AND LOOKS LIKE THE ACCUMULATING SNOW WILL BE
TONIGHT WHERE UP TO 2 INCHES COULD FALL ACROSS THE WESTERN
HIGHLANDS. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
TEMPERATURE FORECAST AND WENT WITH CATEGORICAL POPS FOR TODAY FOR
THE CWA AND THEN LIKELY POPS IN NORTHWEST LAKE EFFECT BELTS TONIGHT
AND KEPT SOME SLIGHT CHANCE POPS IN THE FAR SOUTH DUE TO THE UPPER
LOW MOVING INTO THE AREA AND WRAPAROUND PCPN IN THE AREA.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 PM EDT MON APR 20 2015

A LARGE UPPER LOW CENTERED OVER NORTHERN ONTARIO WILL BE
INFLUENCING THE GREAT LAKES REGION THROUGH THE FIRST HALF OF THE
LONG TERM PERIOD. THIS WILL LEAD TO BELOW NORMAL TEMPERATURES AND
PERIODS OF SNOW BEFORE GRADUALLY SHIFTING EAST INTO THE ATLANTIC BY
THE WEEKEND.

AS THAT UPPER LOW SPINS BETWEEN LAKE SUPERIOR AND JAMES BAY...IT
WILL ROTATE SEVERAL SHORTWAVES ACROSS THE UPPER GREAT LAKES REGION
TUESDAY NIGHT THROUGH THURSDAY. THESE WAVES WILL BRING PERIODS OF
SHOWERS TO THE AREA...WITH HELP FROM BOTH LAKE SUPERIOR (850MB
TEMPS FALLING TO -10C TO -12C ON WEDNESDAY MORNING) AND TERRAIN
ENHANCEMENT (PERSISTENT LOW LEVEL NORTHWESTERLY FLOW). WILL CONTINUE
TO FOCUS THE HIGHEST POPS (LIKELY VALUES) IN THOSE AREAS FAVORED BY
ALL THREE FEATURES (HIGHER TERRAIN OF THE WEST/NORTHWEST) AND ALSO
EAST DOWNWIND OF LAKE SUPERIOR...AND INCLUDE CHANCE/SLIGHTS FOR THE
REST OF THE CWA. WITH THE AMOUNT OF COLD AIR IN PLACE...EXPECT THE
PRECIPITATION TO FALL MAINLY AS SNOW. WITH LOW LEVEL TEMPERATURES
WARMING AWAY OVER THE SOUTHERN THIRD OF THE CWA...COULD SEE SOME
RAIN MIXING IN THERE...BUT OTHERWISE SNOW WILL BE THE NORM. COULD
SEE A COUPLE INCHES OF ACCUMULATION IN THE FAVORED LOCATIONS
TUESDAY NIGHT AND UP TO AN INCH WEDNESDAY AND AGAIN WEDNESDAY
NIGHT. WITH DRIER AIR STARTING TO MOVE INTO THE AREA ON
THURSDAY (ASSOCIATED WITH A SURFACE RIDGE MOVING INTO THE
NORTHERN PLAINS...SHOULD SEE THE COVERAGE OF THE SHOWERS
DIMINISHING THROUGH THE DAY THURSDAY AND CONTINUING TO WEAKENING
INTO FRIDAY. ALSO...DON/T EXPECT HIGHS TO RISE MUCH OUT OF THE
LOW-MID 30S ON WED/THURS OVER THE NORTH HALF OF THE CWA...WITH SOME
HIGHS AROUND 40 OVER THE SOUTH CENTRAL. WILL LIKELY BREAK THE
RECORD LOW HIGH TEMPERATURE HERE AT OUR OFFICE ON WEDNESDAY (36 SET
IN 1972).

EXTENDED RANGE MODELS DIFFER ON HOW QUICKLY THE UPPER LOW DEPARTS
THIS WEEKEND...BUT SHOULD STILL SEE ENOUGH INFLUENCE FROM THE
SURFACE RIDGE MOVING INTO THE NORTHERN PLAINS TO KEEP MOST OF THE
AREA DRY. WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR...EXPECT
TEMPERATURES TO REMAIN BELOW NORMAL BUT IN THE 40S TO AROUND 50. AS
THE UPPER LOW RETROGRADES BACK OVER QUEBEC EARLY NEXT WEEK...COULD
SEE THE UPPER GREAT LAKES REGION BEING AFFECTED BY THE WESTERN EDGE
OF THE ENERGY ROTATING AROUND THE UPPER LOW AND LIKELY KEEPING
BELOW NORMAL TEMPERATURES IN PLACE THROUGH THE END OF APRIL.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 131 PM EDT MON APR 20 2015

AREA OF DEEPER MSTR ASSOCIATED WITH BAND OF SHARPER FORCING WL BRING
A PERIOD OF STEADY SN TO CMX THRU THIS AFTN ALONG WITH LIFR
CONDITIONS. GUSTY W WINDS TO NEAR 30 KTS WL ALSO IMPACT THIS MORE
EXPOSED LOCATION. THE AREA OF PCPN WL EXIT IWD SOON AFTER TAF
ISSUANCE...SO EXPECT AN IMPROVEMENT THERE FM IFR TO MVFR WITH THE
ARRIVAL OF SOME DRIER AIR/SUBSIDENCE. SINCE THE BAND OF HEAVIER PCPN
IS LIKELY TO REMAIN TO THE W OF SAW...THERE SHOULD BE MVFR CIGS WITH
ONLY SOME OCNL -SHRA IN THE PRESENCE OF A DOWNSLOPE WIND COMPONENT.
FOR THIS EVNG...MVFR CONDITIONS SHOULD BE THE RULE WITH MVFR CIGS
AND ONLY SOME SCT LIGHT -SHSN OR -SHSNRA. BUT THE APRCH OF ANOTHER
DISTURBANCE/LO PRES TROF LATE TNGT SHOULD RESULT IN DETERIORATING
CONDITIONS AGAIN WITH IFR CONDITIONS DVLPG AT IWD AND CMX. DOWNSLOPE
WINDS AT SAW WL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO IWD AND CMX BY LATE MRNG ON TUE.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT MON APR 20 2015

AS A LOW LIFTS THROUGH THE SOO THIS AFTERNOON...WINDS WILL BACK TO
THE WEST-NORTHWEST THIS AFTERNOON. WITH THE LOW BECOMING STATIONARY
JUST TO THE SOUTHWEST OF JAMES BAY TONIGHT THROUGH
WEDNESDAY...PERSISTENT NORTHWESTERLY WINDS OF 20-30KTS ARE EXPECTED.
ALTHOUGH THE LOW WILL WEAKEN AND MOVE EAST ACROSS QUEBEC WEDNESDAY
NIGHT INTO THURSDAY...THE NORTHWEST WINDS UP TO 25KTS WILL PERSIST
AS A RIDGE MOVES INTO THE NORTHERN PLAINS. THE WINDS DIMINISH THEN
BELOW 20 KNOTS BY THURSDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...SRF
AVIATION...KC
MARINE...07




000
FXUS63 KMQT 201939
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
339 PM EDT MON APR 20 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT MON APR 20 2015

UPPER AIR PATTERN CONSISTS OF A ELONGATED 500 MB TROUGH WITH SEVERAL
SHORTWAVES EMBEDDED IN IT. THE SHORTWAVE OVER LOWER MICHIGAN WILL BE
SPREADING PCPN UP INTO THE CWA THIS MORNING WHILE ANOTHER SHORTWAVE
OVER THE RED RIVER VALLEY OF THE NORTH WILL PUT PCPN IN OVER THE FAR
WEST THIS MORNING. BOTH THESE SHORTWAVES WILL COMBINE OVER THE AREA
AND CAUSE SOME WIDESPREAD PCPN THIS MORNING OVER THE CWA. UPPER
TROUGH SLOWLY MOVES EAST WITH A 500 MB LOW MOVING OVER THE U.P. LATE
TONIGHT. NAM SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE OVER THE CWA THIS MORNING. THE DEEPER MOISTURE REMAIN
OVER THE AREA THROUGH TONIGHT WHILE THE Q-VECTOR CONVERGENCE WEAKENS
AND MOVES OUT BY THIS EVENING BEFORE MOVING BACK IN LATE TONIGHT
WITH THE 500 MB LOW. GFS AND ECMWF SHOW ABOUT THE SAME THING AS
WELL.

HAD TO HANG ONTO THE DRIER AIR ACROSS THE CENTRAL CWA A BIT LONGER
THIS MORNING AND CUT THE QPF AMOUNTS BECAUSE OF THIS. DID GO WITH A
COMBO OF WET BULB HEIGHTS AND WARM TEMPERATURES ALOFT TO DETERMINE
SNOW FOR THIS FORECAST AND LOOKS LIKE THE ACCUMULATING SNOW WILL BE
TONIGHT WHERE UP TO 2 INCHES COULD FALL ACROSS THE WESTERN
HIGHLANDS. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
TEMPERATURE FORECAST AND WENT WITH CATEGORICAL POPS FOR TODAY FOR
THE CWA AND THEN LIKELY POPS IN NORTHWEST LAKE EFFECT BELTS TONIGHT
AND KEPT SOME SLIGHT CHANCE POPS IN THE FAR SOUTH DUE TO THE UPPER
LOW MOVING INTO THE AREA AND WRAPAROUND PCPN IN THE AREA.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 PM EDT MON APR 20 2015

A LARGE UPPER LOW CENTERED OVER NORTHERN ONTARIO WILL BE
INFLUENCING THE GREAT LAKES REGION THROUGH THE FIRST HALF OF THE
LONG TERM PERIOD. THIS WILL LEAD TO BELOW NORMAL TEMPERATURES AND
PERIODS OF SNOW BEFORE GRADUALLY SHIFTING EAST INTO THE ATLANTIC BY
THE WEEKEND.

AS THAT UPPER LOW SPINS BETWEEN LAKE SUPERIOR AND JAMES BAY...IT
WILL ROTATE SEVERAL SHORTWAVES ACROSS THE UPPER GREAT LAKES REGION
TUESDAY NIGHT THROUGH THURSDAY. THESE WAVES WILL BRING PERIODS OF
SHOWERS TO THE AREA...WITH HELP FROM BOTH LAKE SUPERIOR (850MB
TEMPS FALLING TO -10C TO -12C ON WEDNESDAY MORNING) AND TERRAIN
ENHANCEMENT (PERSISTENT LOW LEVEL NORTHWESTERLY FLOW). WILL CONTINUE
TO FOCUS THE HIGHEST POPS (LIKELY VALUES) IN THOSE AREAS FAVORED BY
ALL THREE FEATURES (HIGHER TERRAIN OF THE WEST/NORTHWEST) AND ALSO
EAST DOWNWIND OF LAKE SUPERIOR...AND INCLUDE CHANCE/SLIGHTS FOR THE
REST OF THE CWA. WITH THE AMOUNT OF COLD AIR IN PLACE...EXPECT THE
PRECIPITATION TO FALL MAINLY AS SNOW. WITH LOW LEVEL TEMPERATURES
WARMING AWAY OVER THE SOUTHERN THIRD OF THE CWA...COULD SEE SOME
RAIN MIXING IN THERE...BUT OTHERWISE SNOW WILL BE THE NORM. COULD
SEE A COUPLE INCHES OF ACCUMULATION IN THE FAVORED LOCATIONS
TUESDAY NIGHT AND UP TO AN INCH WEDNESDAY AND AGAIN WEDNESDAY
NIGHT. WITH DRIER AIR STARTING TO MOVE INTO THE AREA ON
THURSDAY (ASSOCIATED WITH A SURFACE RIDGE MOVING INTO THE
NORTHERN PLAINS...SHOULD SEE THE COVERAGE OF THE SHOWERS
DIMINISHING THROUGH THE DAY THURSDAY AND CONTINUING TO WEAKENING
INTO FRIDAY. ALSO...DON/T EXPECT HIGHS TO RISE MUCH OUT OF THE
LOW-MID 30S ON WED/THURS OVER THE NORTH HALF OF THE CWA...WITH SOME
HIGHS AROUND 40 OVER THE SOUTH CENTRAL. WILL LIKELY BREAK THE
RECORD LOW HIGH TEMPERATURE HERE AT OUR OFFICE ON WEDNESDAY (36 SET
IN 1972).

EXTENDED RANGE MODELS DIFFER ON HOW QUICKLY THE UPPER LOW DEPARTS
THIS WEEKEND...BUT SHOULD STILL SEE ENOUGH INFLUENCE FROM THE
SURFACE RIDGE MOVING INTO THE NORTHERN PLAINS TO KEEP MOST OF THE
AREA DRY. WITH THE NORTHERLY FLOW OFF LAKE SUPERIOR...EXPECT
TEMPERATURES TO REMAIN BELOW NORMAL BUT IN THE 40S TO AROUND 50. AS
THE UPPER LOW RETROGRADES BACK OVER QUEBEC EARLY NEXT WEEK...COULD
SEE THE UPPER GREAT LAKES REGION BEING AFFECTED BY THE WESTERN EDGE
OF THE ENERGY ROTATING AROUND THE UPPER LOW AND LIKELY KEEPING
BELOW NORMAL TEMPERATURES IN PLACE THROUGH THE END OF APRIL.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 131 PM EDT MON APR 20 2015

AREA OF DEEPER MSTR ASSOCIATED WITH BAND OF SHARPER FORCING WL BRING
A PERIOD OF STEADY SN TO CMX THRU THIS AFTN ALONG WITH LIFR
CONDITIONS. GUSTY W WINDS TO NEAR 30 KTS WL ALSO IMPACT THIS MORE
EXPOSED LOCATION. THE AREA OF PCPN WL EXIT IWD SOON AFTER TAF
ISSUANCE...SO EXPECT AN IMPROVEMENT THERE FM IFR TO MVFR WITH THE
ARRIVAL OF SOME DRIER AIR/SUBSIDENCE. SINCE THE BAND OF HEAVIER PCPN
IS LIKELY TO REMAIN TO THE W OF SAW...THERE SHOULD BE MVFR CIGS WITH
ONLY SOME OCNL -SHRA IN THE PRESENCE OF A DOWNSLOPE WIND COMPONENT.
FOR THIS EVNG...MVFR CONDITIONS SHOULD BE THE RULE WITH MVFR CIGS
AND ONLY SOME SCT LIGHT -SHSN OR -SHSNRA. BUT THE APRCH OF ANOTHER
DISTURBANCE/LO PRES TROF LATE TNGT SHOULD RESULT IN DETERIORATING
CONDITIONS AGAIN WITH IFR CONDITIONS DVLPG AT IWD AND CMX. DOWNSLOPE
WINDS AT SAW WL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO IWD AND CMX BY LATE MRNG ON TUE.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT MON APR 20 2015

AS A LOW LIFTS THROUGH THE SOO THIS AFTERNOON...WINDS WILL BACK TO
THE WEST-NORTHWEST THIS AFTERNOON. WITH THE LOW BECOMING STATIONARY
JUST TO THE SOUTHWEST OF JAMES BAY TONIGHT THROUGH
WEDNESDAY...PERSISTENT NORTHWESTERLY WINDS OF 20-30KTS ARE EXPECTED.
ALTHOUGH THE LOW WILL WEAKEN AND MOVE EAST ACROSS QUEBEC WEDNESDAY
NIGHT INTO THURSDAY...THE NORTHWEST WINDS UP TO 25KTS WILL PERSIST
AS A RIDGE MOVES INTO THE NORTHERN PLAINS. THE WINDS DIMINISH THEN
BELOW 20 KNOTS BY THURSDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...SRF
AVIATION...KC
MARINE...07




000
FXUS63 KGRR 201929
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
329 PM EDT MON APR 20 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE

.SYNOPSIS...
ISSUED AT 330 PM EDT MON APR 20 2015

A STALLED STORM SYSEM OVER THE NORTHERN GREAT LAKES WILL KEEP
SHOWERS AND UNSEASONABLY COLD WEATHER THROUGH A GOOD PART OF THIS
WEEK. THE SHOWERS MAY BE MIXED WITH SNOW OR TURN TO SNOW AT TIMES
TUESDAY NIGHT INTO THURSDAY. ANY ACCUMULATIONS WILL BE MINOR.
FREEZING TEMPERATURES ARE EXPECTED EACH MORNING STARTING ON
WEDNESDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 330 PM EDT MON APR 20 2015


THE MAIN ISSUE IS THE PRECIPITATION THREAT AND RISK OF SNOW
TUESDAY NIGHT INTO WEDNESDAY NIGHT. OUR STALLED LOW PRESSURE
SYSTEM WILL CONTINUE BRING COLDER AIR INTO THE REGION INTO
WEDNESDAY. SHORTWAVES ROTATING AROUND THE STALLED SYSTEM WILL KEEP
SHOWERS GOING THROUGH THE SHORT TERM. WITH THE LAKE TEMPERATURE
NEAR 3C... AND 850 TEMPS FALLING TO NEAR -8C.... THAT IS MARINGAL
FOR LAKE EFFECT BUT GIVEN THERE IS ENOUGH MOISTURE IN THE 950 TO
700 MB LAYER THROUGH THIS TIME PERIOD SHOWERS WILL CONTINUE AS
WELL AS GUSTY WINDS. BY TUESDAY NIGHT IT GETS COLD ENOUGH FOR
MIXER RAIN AND SNOW AND THAT THREAT CONTINUES INTO WEDNESDAY
NIGHT.




.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 330 PM EDT MON APR 20 2015

UNSEASONABLY COOL WEATHER WILL CONTINUE THURSDAY WITH THE UPPER
TROUGH AXIS IN PLACE OVER THE EASTERN GREAT LAKES REGION AND DEEP
CYCLONIC FLOW. SCATTERED RAIN SHOWERS WILL LINGER THURSDAY AND MAY
BE MIXED AT TIMES WITH WET SNOW FLAKES PARTICULARLY ACROSS HIGHER
ELEVATIONS OF OUR NORTHERN FCST AREA.

THE UPPER TROUGH WILL SHIFT FURTHER EAST THURSDAY NIGHT AS A SFC
RIDGE BEGINS TO BUILD IN. THIS WILL LIKELY SET THE STAGE FOR A
COLDER NIGHT DEPENDING ON EXTENT AND TIMING OF CLEARING AS THE RIDGE
BEGINS TO BUILD IN. THERE IS POTENTIAL FOR WIDESPREAD TEMPS IN THE
25 TO 30 DEGREE RANGE BY EARLY FRIDAY MORNING SO FROST/FREEZE ISSUES
ARE CERTAINLY A CONCERN FOR LATE WEEK.

THE SFC HIGH PRESSURE RIDGE WILL BRING FAIR BUT COOL WEATHER FRIDAY
INTO SATURDAY. MAX TEMPS BY FRIDAY SHOULD REACH THE UPPER 40S TO
LOWER 50S WITH MIN TEMPS FRIDAY NIGHT IN THE 20S TO AROUND 30
DEGREES. TEMPERATURES WILL UNDERGO A SLOW MODERATING TREND FOR THE
WEEKEND INTO EARLY NEXT WEEK WITH FAIR WX EXPECTED TO CONTINUE WITH
THE SFC RIDGE REMAINING IN CONTROL OF THE WX PATTERN.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY)
ISSUED AT 1220 PM EDT MON APR 20 2015

MAINLY IFR/MVFR CONDITIONS WILL CONTINUE THROUGH MID TO LATE
AFTERNOON DUE TO LOW CIGS AND SCATTERED SHOWERS AND PATCHY FOG
BEFORE GRADUALLY IMPROVING TO VFR THIS EVENING AND OVERNIGHT.

IT WILL BE BREEZY THIS AFTERNOON WITH SW WINDS OF 15 TO 25 KTS WITH
GUSTS TO AROUND 30 KTS. SOUTHWEST TO WEST WINDS WILL STAY UP AROUND
15 TO 25 KTS OVERNIGHT AND THEN VEER TO THE WEST AND INCREASE TO 20
TO 25 KTS WITH GUSTS TO AROUND 30 KTS BY MID TO LATE TUESDAY MORNING.

SCATTERED LIGHT RAIN SHOWERS WILL LINGER OVERNIGHT AND THEN BECOME
MORE PREVALENT ON TUESDAY. MAINLY VFR CONDITIONS ARE ANTICIPATED
TUESDAY ALTHOUGH SOME PATCHY MVFR IS POSSIBLE DUE TO LOWER CIGS AND
HEAVIER SHOWERS.


&&

.MARINE...
ISSUED AT 330 PM EDT MON APR 20 2015

I EXTENTED THE AREA COVERED BY THE SCA TO COVER THE ENTIRE NEAR
SHORE. I ALSO CONTINUED IT THROUGH WEDNESDAY AFTERNOON. WITH OUR
SYSTEM STALLED OVER THE GREAT LAKES MOST OF THE WEEK WE WILL SEE A
CONTINUATION OF 15 TO 25 KNOT WINDS FROM THE SOUTHWEST INTO
TUESDAY THEN NORTHWEST TUESDAY NIGHT THROUGH A GOOD PART OF THE
REST OF THE WEEK.

&&

.HYDROLOGY...
ISSUED AT 1156 AM EDT MON APR 20 2015

WIDESPREAD RAINFALL THROUGH 8 AM THIS MORNING PRODUCED 0.50 TO 0.75
INCHES ACROSS MOST OF THE GRAND AND MUSKEGON RIVER BASINS. FURTHER
SOUTH ACROSS THE KALAMAZOO RIVER BASIN...RAINFALL AMOUNTS WERE
HIGHER IN THE 0.75 TO 1.00 INCH RANGE. AS EXPECTED...GRADUAL RIVER
RISES HAVE BEGUN ON MOST AREA RIVERS. GENERAL HYDRO THINKING HAS NOT
CHANGED MUCH...MOSTLY WITHIN BANK RISES ARE EXPECTED. A FEW SITES
COULD EXCEED BANKFULL. BUT WITH RAIN TODAY AND TONIGHT BEING OF THE
SCATTERED AND LIGHT VARIETY...SIGNIFICANT FLOODING IS NOT EXPECTED.

FORECAST RAINFALL TODAY AND TONIGHT IS IN THE 0.10 TO 0.25 INCH
RANGE. EVEN LIGHTER PRECIP AMOUNTS ARE EXPECTED TUESDAY
INTO WEDNESDAY. A SLIGHT CHANCE OF LIGHT RAIN AND SNOW WILL LINGER
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. BUT MAINLY DRY AND CHILLY
WEATHER IS EXPECTED TOWARD THE END OF THE WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...LAURENS
HYDROLOGY...EBW
MARINE...WDM







000
FXUS63 KGRR 201929
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
329 PM EDT MON APR 20 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE

.SYNOPSIS...
ISSUED AT 330 PM EDT MON APR 20 2015

A STALLED STORM SYSEM OVER THE NORTHERN GREAT LAKES WILL KEEP
SHOWERS AND UNSEASONABLY COLD WEATHER THROUGH A GOOD PART OF THIS
WEEK. THE SHOWERS MAY BE MIXED WITH SNOW OR TURN TO SNOW AT TIMES
TUESDAY NIGHT INTO THURSDAY. ANY ACCUMULATIONS WILL BE MINOR.
FREEZING TEMPERATURES ARE EXPECTED EACH MORNING STARTING ON
WEDNESDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 330 PM EDT MON APR 20 2015


THE MAIN ISSUE IS THE PRECIPITATION THREAT AND RISK OF SNOW
TUESDAY NIGHT INTO WEDNESDAY NIGHT. OUR STALLED LOW PRESSURE
SYSTEM WILL CONTINUE BRING COLDER AIR INTO THE REGION INTO
WEDNESDAY. SHORTWAVES ROTATING AROUND THE STALLED SYSTEM WILL KEEP
SHOWERS GOING THROUGH THE SHORT TERM. WITH THE LAKE TEMPERATURE
NEAR 3C... AND 850 TEMPS FALLING TO NEAR -8C.... THAT IS MARINGAL
FOR LAKE EFFECT BUT GIVEN THERE IS ENOUGH MOISTURE IN THE 950 TO
700 MB LAYER THROUGH THIS TIME PERIOD SHOWERS WILL CONTINUE AS
WELL AS GUSTY WINDS. BY TUESDAY NIGHT IT GETS COLD ENOUGH FOR
MIXER RAIN AND SNOW AND THAT THREAT CONTINUES INTO WEDNESDAY
NIGHT.




.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 330 PM EDT MON APR 20 2015

UNSEASONABLY COOL WEATHER WILL CONTINUE THURSDAY WITH THE UPPER
TROUGH AXIS IN PLACE OVER THE EASTERN GREAT LAKES REGION AND DEEP
CYCLONIC FLOW. SCATTERED RAIN SHOWERS WILL LINGER THURSDAY AND MAY
BE MIXED AT TIMES WITH WET SNOW FLAKES PARTICULARLY ACROSS HIGHER
ELEVATIONS OF OUR NORTHERN FCST AREA.

THE UPPER TROUGH WILL SHIFT FURTHER EAST THURSDAY NIGHT AS A SFC
RIDGE BEGINS TO BUILD IN. THIS WILL LIKELY SET THE STAGE FOR A
COLDER NIGHT DEPENDING ON EXTENT AND TIMING OF CLEARING AS THE RIDGE
BEGINS TO BUILD IN. THERE IS POTENTIAL FOR WIDESPREAD TEMPS IN THE
25 TO 30 DEGREE RANGE BY EARLY FRIDAY MORNING SO FROST/FREEZE ISSUES
ARE CERTAINLY A CONCERN FOR LATE WEEK.

THE SFC HIGH PRESSURE RIDGE WILL BRING FAIR BUT COOL WEATHER FRIDAY
INTO SATURDAY. MAX TEMPS BY FRIDAY SHOULD REACH THE UPPER 40S TO
LOWER 50S WITH MIN TEMPS FRIDAY NIGHT IN THE 20S TO AROUND 30
DEGREES. TEMPERATURES WILL UNDERGO A SLOW MODERATING TREND FOR THE
WEEKEND INTO EARLY NEXT WEEK WITH FAIR WX EXPECTED TO CONTINUE WITH
THE SFC RIDGE REMAINING IN CONTROL OF THE WX PATTERN.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY)
ISSUED AT 1220 PM EDT MON APR 20 2015

MAINLY IFR/MVFR CONDITIONS WILL CONTINUE THROUGH MID TO LATE
AFTERNOON DUE TO LOW CIGS AND SCATTERED SHOWERS AND PATCHY FOG
BEFORE GRADUALLY IMPROVING TO VFR THIS EVENING AND OVERNIGHT.

IT WILL BE BREEZY THIS AFTERNOON WITH SW WINDS OF 15 TO 25 KTS WITH
GUSTS TO AROUND 30 KTS. SOUTHWEST TO WEST WINDS WILL STAY UP AROUND
15 TO 25 KTS OVERNIGHT AND THEN VEER TO THE WEST AND INCREASE TO 20
TO 25 KTS WITH GUSTS TO AROUND 30 KTS BY MID TO LATE TUESDAY MORNING.

SCATTERED LIGHT RAIN SHOWERS WILL LINGER OVERNIGHT AND THEN BECOME
MORE PREVALENT ON TUESDAY. MAINLY VFR CONDITIONS ARE ANTICIPATED
TUESDAY ALTHOUGH SOME PATCHY MVFR IS POSSIBLE DUE TO LOWER CIGS AND
HEAVIER SHOWERS.


&&

.MARINE...
ISSUED AT 330 PM EDT MON APR 20 2015

I EXTENTED THE AREA COVERED BY THE SCA TO COVER THE ENTIRE NEAR
SHORE. I ALSO CONTINUED IT THROUGH WEDNESDAY AFTERNOON. WITH OUR
SYSTEM STALLED OVER THE GREAT LAKES MOST OF THE WEEK WE WILL SEE A
CONTINUATION OF 15 TO 25 KNOT WINDS FROM THE SOUTHWEST INTO
TUESDAY THEN NORTHWEST TUESDAY NIGHT THROUGH A GOOD PART OF THE
REST OF THE WEEK.

&&

.HYDROLOGY...
ISSUED AT 1156 AM EDT MON APR 20 2015

WIDESPREAD RAINFALL THROUGH 8 AM THIS MORNING PRODUCED 0.50 TO 0.75
INCHES ACROSS MOST OF THE GRAND AND MUSKEGON RIVER BASINS. FURTHER
SOUTH ACROSS THE KALAMAZOO RIVER BASIN...RAINFALL AMOUNTS WERE
HIGHER IN THE 0.75 TO 1.00 INCH RANGE. AS EXPECTED...GRADUAL RIVER
RISES HAVE BEGUN ON MOST AREA RIVERS. GENERAL HYDRO THINKING HAS NOT
CHANGED MUCH...MOSTLY WITHIN BANK RISES ARE EXPECTED. A FEW SITES
COULD EXCEED BANKFULL. BUT WITH RAIN TODAY AND TONIGHT BEING OF THE
SCATTERED AND LIGHT VARIETY...SIGNIFICANT FLOODING IS NOT EXPECTED.

FORECAST RAINFALL TODAY AND TONIGHT IS IN THE 0.10 TO 0.25 INCH
RANGE. EVEN LIGHTER PRECIP AMOUNTS ARE EXPECTED TUESDAY
INTO WEDNESDAY. A SLIGHT CHANCE OF LIGHT RAIN AND SNOW WILL LINGER
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. BUT MAINLY DRY AND CHILLY
WEATHER IS EXPECTED TOWARD THE END OF THE WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...LAURENS
HYDROLOGY...EBW
MARINE...WDM






000
FXUS63 KGRR 201929
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
329 PM EDT MON APR 20 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE

.SYNOPSIS...
ISSUED AT 330 PM EDT MON APR 20 2015

A STALLED STORM SYSEM OVER THE NORTHERN GREAT LAKES WILL KEEP
SHOWERS AND UNSEASONABLY COLD WEATHER THROUGH A GOOD PART OF THIS
WEEK. THE SHOWERS MAY BE MIXED WITH SNOW OR TURN TO SNOW AT TIMES
TUESDAY NIGHT INTO THURSDAY. ANY ACCUMULATIONS WILL BE MINOR.
FREEZING TEMPERATURES ARE EXPECTED EACH MORNING STARTING ON
WEDNESDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 330 PM EDT MON APR 20 2015


THE MAIN ISSUE IS THE PRECIPITATION THREAT AND RISK OF SNOW
TUESDAY NIGHT INTO WEDNESDAY NIGHT. OUR STALLED LOW PRESSURE
SYSTEM WILL CONTINUE BRING COLDER AIR INTO THE REGION INTO
WEDNESDAY. SHORTWAVES ROTATING AROUND THE STALLED SYSTEM WILL KEEP
SHOWERS GOING THROUGH THE SHORT TERM. WITH THE LAKE TEMPERATURE
NEAR 3C... AND 850 TEMPS FALLING TO NEAR -8C.... THAT IS MARINGAL
FOR LAKE EFFECT BUT GIVEN THERE IS ENOUGH MOISTURE IN THE 950 TO
700 MB LAYER THROUGH THIS TIME PERIOD SHOWERS WILL CONTINUE AS
WELL AS GUSTY WINDS. BY TUESDAY NIGHT IT GETS COLD ENOUGH FOR
MIXER RAIN AND SNOW AND THAT THREAT CONTINUES INTO WEDNESDAY
NIGHT.




.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 330 PM EDT MON APR 20 2015

UNSEASONABLY COOL WEATHER WILL CONTINUE THURSDAY WITH THE UPPER
TROUGH AXIS IN PLACE OVER THE EASTERN GREAT LAKES REGION AND DEEP
CYCLONIC FLOW. SCATTERED RAIN SHOWERS WILL LINGER THURSDAY AND MAY
BE MIXED AT TIMES WITH WET SNOW FLAKES PARTICULARLY ACROSS HIGHER
ELEVATIONS OF OUR NORTHERN FCST AREA.

THE UPPER TROUGH WILL SHIFT FURTHER EAST THURSDAY NIGHT AS A SFC
RIDGE BEGINS TO BUILD IN. THIS WILL LIKELY SET THE STAGE FOR A
COLDER NIGHT DEPENDING ON EXTENT AND TIMING OF CLEARING AS THE RIDGE
BEGINS TO BUILD IN. THERE IS POTENTIAL FOR WIDESPREAD TEMPS IN THE
25 TO 30 DEGREE RANGE BY EARLY FRIDAY MORNING SO FROST/FREEZE ISSUES
ARE CERTAINLY A CONCERN FOR LATE WEEK.

THE SFC HIGH PRESSURE RIDGE WILL BRING FAIR BUT COOL WEATHER FRIDAY
INTO SATURDAY. MAX TEMPS BY FRIDAY SHOULD REACH THE UPPER 40S TO
LOWER 50S WITH MIN TEMPS FRIDAY NIGHT IN THE 20S TO AROUND 30
DEGREES. TEMPERATURES WILL UNDERGO A SLOW MODERATING TREND FOR THE
WEEKEND INTO EARLY NEXT WEEK WITH FAIR WX EXPECTED TO CONTINUE WITH
THE SFC RIDGE REMAINING IN CONTROL OF THE WX PATTERN.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY)
ISSUED AT 1220 PM EDT MON APR 20 2015

MAINLY IFR/MVFR CONDITIONS WILL CONTINUE THROUGH MID TO LATE
AFTERNOON DUE TO LOW CIGS AND SCATTERED SHOWERS AND PATCHY FOG
BEFORE GRADUALLY IMPROVING TO VFR THIS EVENING AND OVERNIGHT.

IT WILL BE BREEZY THIS AFTERNOON WITH SW WINDS OF 15 TO 25 KTS WITH
GUSTS TO AROUND 30 KTS. SOUTHWEST TO WEST WINDS WILL STAY UP AROUND
15 TO 25 KTS OVERNIGHT AND THEN VEER TO THE WEST AND INCREASE TO 20
TO 25 KTS WITH GUSTS TO AROUND 30 KTS BY MID TO LATE TUESDAY MORNING.

SCATTERED LIGHT RAIN SHOWERS WILL LINGER OVERNIGHT AND THEN BECOME
MORE PREVALENT ON TUESDAY. MAINLY VFR CONDITIONS ARE ANTICIPATED
TUESDAY ALTHOUGH SOME PATCHY MVFR IS POSSIBLE DUE TO LOWER CIGS AND
HEAVIER SHOWERS.


&&

.MARINE...
ISSUED AT 330 PM EDT MON APR 20 2015

I EXTENTED THE AREA COVERED BY THE SCA TO COVER THE ENTIRE NEAR
SHORE. I ALSO CONTINUED IT THROUGH WEDNESDAY AFTERNOON. WITH OUR
SYSTEM STALLED OVER THE GREAT LAKES MOST OF THE WEEK WE WILL SEE A
CONTINUATION OF 15 TO 25 KNOT WINDS FROM THE SOUTHWEST INTO
TUESDAY THEN NORTHWEST TUESDAY NIGHT THROUGH A GOOD PART OF THE
REST OF THE WEEK.

&&

.HYDROLOGY...
ISSUED AT 1156 AM EDT MON APR 20 2015

WIDESPREAD RAINFALL THROUGH 8 AM THIS MORNING PRODUCED 0.50 TO 0.75
INCHES ACROSS MOST OF THE GRAND AND MUSKEGON RIVER BASINS. FURTHER
SOUTH ACROSS THE KALAMAZOO RIVER BASIN...RAINFALL AMOUNTS WERE
HIGHER IN THE 0.75 TO 1.00 INCH RANGE. AS EXPECTED...GRADUAL RIVER
RISES HAVE BEGUN ON MOST AREA RIVERS. GENERAL HYDRO THINKING HAS NOT
CHANGED MUCH...MOSTLY WITHIN BANK RISES ARE EXPECTED. A FEW SITES
COULD EXCEED BANKFULL. BUT WITH RAIN TODAY AND TONIGHT BEING OF THE
SCATTERED AND LIGHT VARIETY...SIGNIFICANT FLOODING IS NOT EXPECTED.

FORECAST RAINFALL TODAY AND TONIGHT IS IN THE 0.10 TO 0.25 INCH
RANGE. EVEN LIGHTER PRECIP AMOUNTS ARE EXPECTED TUESDAY
INTO WEDNESDAY. A SLIGHT CHANCE OF LIGHT RAIN AND SNOW WILL LINGER
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. BUT MAINLY DRY AND CHILLY
WEATHER IS EXPECTED TOWARD THE END OF THE WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...LAURENS
HYDROLOGY...EBW
MARINE...WDM






000
FXUS63 KGRR 201929
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
329 PM EDT MON APR 20 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE

.SYNOPSIS...
ISSUED AT 330 PM EDT MON APR 20 2015

A STALLED STORM SYSEM OVER THE NORTHERN GREAT LAKES WILL KEEP
SHOWERS AND UNSEASONABLY COLD WEATHER THROUGH A GOOD PART OF THIS
WEEK. THE SHOWERS MAY BE MIXED WITH SNOW OR TURN TO SNOW AT TIMES
TUESDAY NIGHT INTO THURSDAY. ANY ACCUMULATIONS WILL BE MINOR.
FREEZING TEMPERATURES ARE EXPECTED EACH MORNING STARTING ON
WEDNESDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 330 PM EDT MON APR 20 2015


THE MAIN ISSUE IS THE PRECIPITATION THREAT AND RISK OF SNOW
TUESDAY NIGHT INTO WEDNESDAY NIGHT. OUR STALLED LOW PRESSURE
SYSTEM WILL CONTINUE BRING COLDER AIR INTO THE REGION INTO
WEDNESDAY. SHORTWAVES ROTATING AROUND THE STALLED SYSTEM WILL KEEP
SHOWERS GOING THROUGH THE SHORT TERM. WITH THE LAKE TEMPERATURE
NEAR 3C... AND 850 TEMPS FALLING TO NEAR -8C.... THAT IS MARINGAL
FOR LAKE EFFECT BUT GIVEN THERE IS ENOUGH MOISTURE IN THE 950 TO
700 MB LAYER THROUGH THIS TIME PERIOD SHOWERS WILL CONTINUE AS
WELL AS GUSTY WINDS. BY TUESDAY NIGHT IT GETS COLD ENOUGH FOR
MIXER RAIN AND SNOW AND THAT THREAT CONTINUES INTO WEDNESDAY
NIGHT.




.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 330 PM EDT MON APR 20 2015

UNSEASONABLY COOL WEATHER WILL CONTINUE THURSDAY WITH THE UPPER
TROUGH AXIS IN PLACE OVER THE EASTERN GREAT LAKES REGION AND DEEP
CYCLONIC FLOW. SCATTERED RAIN SHOWERS WILL LINGER THURSDAY AND MAY
BE MIXED AT TIMES WITH WET SNOW FLAKES PARTICULARLY ACROSS HIGHER
ELEVATIONS OF OUR NORTHERN FCST AREA.

THE UPPER TROUGH WILL SHIFT FURTHER EAST THURSDAY NIGHT AS A SFC
RIDGE BEGINS TO BUILD IN. THIS WILL LIKELY SET THE STAGE FOR A
COLDER NIGHT DEPENDING ON EXTENT AND TIMING OF CLEARING AS THE RIDGE
BEGINS TO BUILD IN. THERE IS POTENTIAL FOR WIDESPREAD TEMPS IN THE
25 TO 30 DEGREE RANGE BY EARLY FRIDAY MORNING SO FROST/FREEZE ISSUES
ARE CERTAINLY A CONCERN FOR LATE WEEK.

THE SFC HIGH PRESSURE RIDGE WILL BRING FAIR BUT COOL WEATHER FRIDAY
INTO SATURDAY. MAX TEMPS BY FRIDAY SHOULD REACH THE UPPER 40S TO
LOWER 50S WITH MIN TEMPS FRIDAY NIGHT IN THE 20S TO AROUND 30
DEGREES. TEMPERATURES WILL UNDERGO A SLOW MODERATING TREND FOR THE
WEEKEND INTO EARLY NEXT WEEK WITH FAIR WX EXPECTED TO CONTINUE WITH
THE SFC RIDGE REMAINING IN CONTROL OF THE WX PATTERN.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY)
ISSUED AT 1220 PM EDT MON APR 20 2015

MAINLY IFR/MVFR CONDITIONS WILL CONTINUE THROUGH MID TO LATE
AFTERNOON DUE TO LOW CIGS AND SCATTERED SHOWERS AND PATCHY FOG
BEFORE GRADUALLY IMPROVING TO VFR THIS EVENING AND OVERNIGHT.

IT WILL BE BREEZY THIS AFTERNOON WITH SW WINDS OF 15 TO 25 KTS WITH
GUSTS TO AROUND 30 KTS. SOUTHWEST TO WEST WINDS WILL STAY UP AROUND
15 TO 25 KTS OVERNIGHT AND THEN VEER TO THE WEST AND INCREASE TO 20
TO 25 KTS WITH GUSTS TO AROUND 30 KTS BY MID TO LATE TUESDAY MORNING.

SCATTERED LIGHT RAIN SHOWERS WILL LINGER OVERNIGHT AND THEN BECOME
MORE PREVALENT ON TUESDAY. MAINLY VFR CONDITIONS ARE ANTICIPATED
TUESDAY ALTHOUGH SOME PATCHY MVFR IS POSSIBLE DUE TO LOWER CIGS AND
HEAVIER SHOWERS.


&&

.MARINE...
ISSUED AT 330 PM EDT MON APR 20 2015

I EXTENTED THE AREA COVERED BY THE SCA TO COVER THE ENTIRE NEAR
SHORE. I ALSO CONTINUED IT THROUGH WEDNESDAY AFTERNOON. WITH OUR
SYSTEM STALLED OVER THE GREAT LAKES MOST OF THE WEEK WE WILL SEE A
CONTINUATION OF 15 TO 25 KNOT WINDS FROM THE SOUTHWEST INTO
TUESDAY THEN NORTHWEST TUESDAY NIGHT THROUGH A GOOD PART OF THE
REST OF THE WEEK.

&&

.HYDROLOGY...
ISSUED AT 1156 AM EDT MON APR 20 2015

WIDESPREAD RAINFALL THROUGH 8 AM THIS MORNING PRODUCED 0.50 TO 0.75
INCHES ACROSS MOST OF THE GRAND AND MUSKEGON RIVER BASINS. FURTHER
SOUTH ACROSS THE KALAMAZOO RIVER BASIN...RAINFALL AMOUNTS WERE
HIGHER IN THE 0.75 TO 1.00 INCH RANGE. AS EXPECTED...GRADUAL RIVER
RISES HAVE BEGUN ON MOST AREA RIVERS. GENERAL HYDRO THINKING HAS NOT
CHANGED MUCH...MOSTLY WITHIN BANK RISES ARE EXPECTED. A FEW SITES
COULD EXCEED BANKFULL. BUT WITH RAIN TODAY AND TONIGHT BEING OF THE
SCATTERED AND LIGHT VARIETY...SIGNIFICANT FLOODING IS NOT EXPECTED.

FORECAST RAINFALL TODAY AND TONIGHT IS IN THE 0.10 TO 0.25 INCH
RANGE. EVEN LIGHTER PRECIP AMOUNTS ARE EXPECTED TUESDAY
INTO WEDNESDAY. A SLIGHT CHANCE OF LIGHT RAIN AND SNOW WILL LINGER
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. BUT MAINLY DRY AND CHILLY
WEATHER IS EXPECTED TOWARD THE END OF THE WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...LAURENS
HYDROLOGY...EBW
MARINE...WDM







000
FXUS63 KAPX 201745
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
ISSUED BY NATIONAL WEATHER SERVICE MARQUETTE MI
145 PM EDT MON APR 20 2015

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 245 AM EDT MON APR 20 2015

LOW PRESSURE CENTER HAS REACHED FAR SW LWR MICHIGAN EARLY THIS
MORNING. WIDESPREAD RAIN NORTH OF THE LOW CENTER HAS SPREAD ACROSS
OUR ENTIRE CWA...WITH ADDITIONAL WIDESPREAD RAIN SHOWER ACTIVITY
EXPANDING AROUND AND EAST OF THE LOW CENTER THANKS TO STRONG 700-500
MB OMEGA AND DEEP MOISTURE CONTINUING TO ADVECT INTO THE REGION.
BOTH THE LATEST NAM AND ECMWF SUGGEST THERE WILL BE A BRIEF DIMINISH
IN POP DURING LATE MORNING/EARLY AFTERNOON AS THE LOW CENTER REACHES
ERN UPR MICHIGAN. DEEP MOISTURE THEN QUICKLY WRAPS BACK INTO
MICHIGAN AS THE LOW CONTINUES NORTHWARD INTO CANADA BY LATE
AFTERNOON. WILL CERTAINLY KEEP CATEGORICAL POPS IN PLACE THRU EARLY
MORNING...WITH ONLY A MINOR DIMINISH IN POPS TO LIKELY ACROSS OUR
SRN CWA THRU THE DAY. ALL THUNDER CHANCES WILL STAY WELL SOUTH OF
MICHIGAN ALONG AND AHEAD OF THE ASSOCIATED WARM FRONT. TEMPS WILL BE
NOTICEABLY COOLER TODAY...WITH HIGH TEMPS RANGING FROM THE MID 40S
IN ERN UPR MICHIGAN TO THE UPPER 50S IN NE LWR MICHIGAN.

SRN EDGE OF WRAP AROUND MOISTURE WILL ALSO LIFT NORTHWARD AS THE
SURFACE LOW DEPARTS DEEP INTO CANADA TONIGHT. HIGHEST POPS (LIKELY)
WILL RESIDE ACROSS THE NRN TWO-THIRDS OF OUR CWA DURING THE EVENING
WHERE LIFT AND WRAP-AROUND MOISTURE WILL LINGER THE LONGEST. ALL
POPS WILL DIMINISH TO CHANCE OVERNIGHT. COLD AIR WRAPPING AROUND THE
DEPARTING LOW WILL DROP 850 MB TEMPS TO AROUND -3 TO -4 C TONIGHT.
WHILE THIS WILL NOT BE SUFFICIENTLY COLD (YET) TO ACTIVATE THE LAKES
TO PROVIDE LAKE ENHANCEMENT TO ONGOING SYNOPTIC PRECIP...BUT IT WILL
BE COLD ENOUGH TO BEGIN TO MIX SOME SNOW IN WITH THE ONGOING RAIN
EVENT DURING THE OVERNIGHT HOURS. EXPECT NO SNOW ACCUMULATION AS
SURFACE TEMPS BOTTOM OUT AT OR A FEW DEGREES ABOVE FREEZING.

&&

.SHORT TERM...(TUESDAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 245 AM EDT MON APR 20 2015

HIGH IMPACT WEATHER POTENTIAL: NOTHING SIGNIFICANT.

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: UNFORTUNATELY...NOW MUCH
TALKED ABOUT CHANGES TO A COOLER WEATHER REGIME ALREADY UNFOLDING AT
THIS EARLY HOUR...WITH ROBUST WEST NOAM RIDGE AMPLIFICATION AND
STRONG SHORTWAVE DIVING ON ITS FRONT SIDE INTO THE NORTHERN PLAINS.
THIS LATTER FEATURE WILL HELP CARVE OUT DEVELOPMENT OF ONE RATHER
IMPRESSIVE UPPER LEVEL LOW ACROSS THE FAR NORTHERN LAKES THROUGH THE
MIDDLE OF THE WEEK...WITH THE FORMER HELPING NEGATE ANY REAL KICKER
SYSTEM TO HELP BOOT THIS SYSTEM OUT. THIS SPELLS A RATHER PROLONGED
PERIOD OF COOL AND DAMP WEATHER...WITH SEVERAL OPPORTUNITIES TO SEE
A LEAST A LITTLE BIT OF SNOW BY THE TIME THIS WORK WEEK WRAPS UP
(QUELL THE EXCITEMENT :)).

PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE TRENDS
AND ADDRESSING PERIODIC PRECIP CHANCES AND TYPE.

DETAILS: CENTER OF UPPER LEVEL COLD CORE GYRE EXPECTED TO SLOWLY
MAKE ITS WAY EAST ACROSS LAKE SUPERIOR TO START THE SHORT TERM
PERIOD (TUESDAY)...ESSENTIALLY STALLING OUT JUST TO OUR NORTH RIGHT
THROUGH WEDNESDAY NIGHT. WHILE AT NO TIMES DOES FORCING SEEM
GREAT...SPOKES OF SUPPORT ROTATING AROUND PARENT SYSTEM COMBINING
WITH DEEP CYCLONIC MOISTURE RICH FLOW AND STEEP LOW/MID LEVEL LAPSE
RATES (H5 TEMPS STILL SLATED TO FLIRT WITH -30C) WILL DEFINITELY
SUPPORT THE THREAT FOR SHOWERS TUESDAY THROUGH WEDNESDAY NIGHT.
GIVEN LACK OF ANY DEEP LAYER TRIGGER...WOULD EXPECT GREATEST SHOWER
COVERAGE TO OCCUR DURING THE LATE MORNING/AFTERNOON HOURS WHEN LOW
LEVEL LAPSE RATES ARE MAXIMIZED. STILL HINTS OVER-RIDING AIRMASS MAY
BECOME JUST COLD ENOUGH TO ENTICE AT LEAST SOME MINOR LAKE
CONTRIBUTION LATE TUESDAY NIGHT INTO WEDNESDAY NIGHT. REAL MARGINAL
DELTA T/S (JUST FLIRTING WITH 13C) SHOULD NEGATE ANY SIGNIFICANT
RESPONSE...ALTHOUGH GOTTA ADMIT SUCH PERSISTENT WEST FLOW UP INTO
THE HIGHLANDS DOES RAISE AN EYEBROW OR TWO. INCREASINGLY COLD OFF
THE DECK THERMAL PROFILES AND STEEP LAPSE RATES DEFINITELY SUPPORTS
SNOW AND GRAUPEL MIXING IN WITH THE SHOWERS DURING THE DAYTIME HOURS
TUESDAY AND WEDNESDAY...WITH THE REAL POSSIBILITY ANY HEAVIER
SHOWERS WILL FALL AS MAINLY SNOW. OVERNIGHT PROFILES CONTINUE TO
SUPPORT MORE OF AN ALL SNOW ENVIRONMENT AS SURFACE BASED MELTING
LAYER IS NEARLY/COMPLETELY LOST. NOT EXPECTING ANY SIGNIFICANT
ACCUMULATIONS...ALTHOUGH WOULD NOT BE SURPRISED FOR THE GROUND TO
TURN WHITE BY WEDNESDAY MORNING (AN INCH OR SO)...ESPECIALLY WHERE
PERSISTENT UPSLOPE FLOW IS REALIZED INTO NORTHWEST LOWER.

AFTER THIS PAST WEEKS PLEASANT WEATHER...JUST GONNA FEEL DOWNRIGHT
CHILLY THROUGH MIDWEEK...WITH HIGHS BACK DOWN INTO THE UPPER 30S/40S
(COLDEST WEDNESDAY) AND OVERNIGHT LOWS A GOOD 10 OR SO DEGREES
COLDER. GUSTY WINDS AND DAMP CONDITIONS WILL ONLY ADD CONSIDERABLE
MORE CHILL. SOUNDS FUN...DOESN`T IT?

&&

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 245 AM EDT MON APR 20 2015

STILL SOME DISCREPANCIES
REGARDING JUST HOW LONG THIS SYSTEM LINGERS INTO THE END OF THE
WEEK...WITH THE GFS/GEFS/GEM NOTABLY SLOWER MOVING IT OUT THAN
RECENT ECMWF/UKMET RUNS. GIVEN UNCERTAINTIES...WILL SIMPLY RIDE WITH
INHERITED FORECAST...FEATURING SOME LINGERING LIGHT RAIN/SNOW
SHOWERS (AT LEAST FOR PARTS OF THE AREA) RIGHT THROUGH
FRIDAY...GIVING WAY TO A DRY WEEKEND. NO MATTER HOW FAST THIS SYSTEM
EXITS...AIRMASS RECOVERY WILL BE A SLOW ONE...SUGGESTING
TEMPERATURES REMAINING BELOW NORMAL RIGHT THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 145 PM EDT MON APR 20 2015

EXPECT IMPROVEMENT AT ALL SITES THIS EVENING INTO TONIGHT AS DRIER
AIR MOVES INTO THE AREA. CONDITIONS WILL THEN DETERIORATE TUE
MORNING AS ANOTHER ROUND OF MOISTURE MOVES IN WITH AN UPPER LEVEL
DISTURBANCE. EXACT TIMING AND MAGNITUDE OF DETERIORATING CONDITIONS
ON TUE IS UNCERTAIN AT THIS TIME.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
     LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LMZ341-
     342-344>346.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LSZ321-
     322.

&&

$$

NEAR TERM...MLR
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...JIT




000
FXUS63 KAPX 201745
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
ISSUED BY NATIONAL WEATHER SERVICE MARQUETTE MI
145 PM EDT MON APR 20 2015

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 245 AM EDT MON APR 20 2015

LOW PRESSURE CENTER HAS REACHED FAR SW LWR MICHIGAN EARLY THIS
MORNING. WIDESPREAD RAIN NORTH OF THE LOW CENTER HAS SPREAD ACROSS
OUR ENTIRE CWA...WITH ADDITIONAL WIDESPREAD RAIN SHOWER ACTIVITY
EXPANDING AROUND AND EAST OF THE LOW CENTER THANKS TO STRONG 700-500
MB OMEGA AND DEEP MOISTURE CONTINUING TO ADVECT INTO THE REGION.
BOTH THE LATEST NAM AND ECMWF SUGGEST THERE WILL BE A BRIEF DIMINISH
IN POP DURING LATE MORNING/EARLY AFTERNOON AS THE LOW CENTER REACHES
ERN UPR MICHIGAN. DEEP MOISTURE THEN QUICKLY WRAPS BACK INTO
MICHIGAN AS THE LOW CONTINUES NORTHWARD INTO CANADA BY LATE
AFTERNOON. WILL CERTAINLY KEEP CATEGORICAL POPS IN PLACE THRU EARLY
MORNING...WITH ONLY A MINOR DIMINISH IN POPS TO LIKELY ACROSS OUR
SRN CWA THRU THE DAY. ALL THUNDER CHANCES WILL STAY WELL SOUTH OF
MICHIGAN ALONG AND AHEAD OF THE ASSOCIATED WARM FRONT. TEMPS WILL BE
NOTICEABLY COOLER TODAY...WITH HIGH TEMPS RANGING FROM THE MID 40S
IN ERN UPR MICHIGAN TO THE UPPER 50S IN NE LWR MICHIGAN.

SRN EDGE OF WRAP AROUND MOISTURE WILL ALSO LIFT NORTHWARD AS THE
SURFACE LOW DEPARTS DEEP INTO CANADA TONIGHT. HIGHEST POPS (LIKELY)
WILL RESIDE ACROSS THE NRN TWO-THIRDS OF OUR CWA DURING THE EVENING
WHERE LIFT AND WRAP-AROUND MOISTURE WILL LINGER THE LONGEST. ALL
POPS WILL DIMINISH TO CHANCE OVERNIGHT. COLD AIR WRAPPING AROUND THE
DEPARTING LOW WILL DROP 850 MB TEMPS TO AROUND -3 TO -4 C TONIGHT.
WHILE THIS WILL NOT BE SUFFICIENTLY COLD (YET) TO ACTIVATE THE LAKES
TO PROVIDE LAKE ENHANCEMENT TO ONGOING SYNOPTIC PRECIP...BUT IT WILL
BE COLD ENOUGH TO BEGIN TO MIX SOME SNOW IN WITH THE ONGOING RAIN
EVENT DURING THE OVERNIGHT HOURS. EXPECT NO SNOW ACCUMULATION AS
SURFACE TEMPS BOTTOM OUT AT OR A FEW DEGREES ABOVE FREEZING.

&&

.SHORT TERM...(TUESDAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 245 AM EDT MON APR 20 2015

HIGH IMPACT WEATHER POTENTIAL: NOTHING SIGNIFICANT.

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: UNFORTUNATELY...NOW MUCH
TALKED ABOUT CHANGES TO A COOLER WEATHER REGIME ALREADY UNFOLDING AT
THIS EARLY HOUR...WITH ROBUST WEST NOAM RIDGE AMPLIFICATION AND
STRONG SHORTWAVE DIVING ON ITS FRONT SIDE INTO THE NORTHERN PLAINS.
THIS LATTER FEATURE WILL HELP CARVE OUT DEVELOPMENT OF ONE RATHER
IMPRESSIVE UPPER LEVEL LOW ACROSS THE FAR NORTHERN LAKES THROUGH THE
MIDDLE OF THE WEEK...WITH THE FORMER HELPING NEGATE ANY REAL KICKER
SYSTEM TO HELP BOOT THIS SYSTEM OUT. THIS SPELLS A RATHER PROLONGED
PERIOD OF COOL AND DAMP WEATHER...WITH SEVERAL OPPORTUNITIES TO SEE
A LEAST A LITTLE BIT OF SNOW BY THE TIME THIS WORK WEEK WRAPS UP
(QUELL THE EXCITEMENT :)).

PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE TRENDS
AND ADDRESSING PERIODIC PRECIP CHANCES AND TYPE.

DETAILS: CENTER OF UPPER LEVEL COLD CORE GYRE EXPECTED TO SLOWLY
MAKE ITS WAY EAST ACROSS LAKE SUPERIOR TO START THE SHORT TERM
PERIOD (TUESDAY)...ESSENTIALLY STALLING OUT JUST TO OUR NORTH RIGHT
THROUGH WEDNESDAY NIGHT. WHILE AT NO TIMES DOES FORCING SEEM
GREAT...SPOKES OF SUPPORT ROTATING AROUND PARENT SYSTEM COMBINING
WITH DEEP CYCLONIC MOISTURE RICH FLOW AND STEEP LOW/MID LEVEL LAPSE
RATES (H5 TEMPS STILL SLATED TO FLIRT WITH -30C) WILL DEFINITELY
SUPPORT THE THREAT FOR SHOWERS TUESDAY THROUGH WEDNESDAY NIGHT.
GIVEN LACK OF ANY DEEP LAYER TRIGGER...WOULD EXPECT GREATEST SHOWER
COVERAGE TO OCCUR DURING THE LATE MORNING/AFTERNOON HOURS WHEN LOW
LEVEL LAPSE RATES ARE MAXIMIZED. STILL HINTS OVER-RIDING AIRMASS MAY
BECOME JUST COLD ENOUGH TO ENTICE AT LEAST SOME MINOR LAKE
CONTRIBUTION LATE TUESDAY NIGHT INTO WEDNESDAY NIGHT. REAL MARGINAL
DELTA T/S (JUST FLIRTING WITH 13C) SHOULD NEGATE ANY SIGNIFICANT
RESPONSE...ALTHOUGH GOTTA ADMIT SUCH PERSISTENT WEST FLOW UP INTO
THE HIGHLANDS DOES RAISE AN EYEBROW OR TWO. INCREASINGLY COLD OFF
THE DECK THERMAL PROFILES AND STEEP LAPSE RATES DEFINITELY SUPPORTS
SNOW AND GRAUPEL MIXING IN WITH THE SHOWERS DURING THE DAYTIME HOURS
TUESDAY AND WEDNESDAY...WITH THE REAL POSSIBILITY ANY HEAVIER
SHOWERS WILL FALL AS MAINLY SNOW. OVERNIGHT PROFILES CONTINUE TO
SUPPORT MORE OF AN ALL SNOW ENVIRONMENT AS SURFACE BASED MELTING
LAYER IS NEARLY/COMPLETELY LOST. NOT EXPECTING ANY SIGNIFICANT
ACCUMULATIONS...ALTHOUGH WOULD NOT BE SURPRISED FOR THE GROUND TO
TURN WHITE BY WEDNESDAY MORNING (AN INCH OR SO)...ESPECIALLY WHERE
PERSISTENT UPSLOPE FLOW IS REALIZED INTO NORTHWEST LOWER.

AFTER THIS PAST WEEKS PLEASANT WEATHER...JUST GONNA FEEL DOWNRIGHT
CHILLY THROUGH MIDWEEK...WITH HIGHS BACK DOWN INTO THE UPPER 30S/40S
(COLDEST WEDNESDAY) AND OVERNIGHT LOWS A GOOD 10 OR SO DEGREES
COLDER. GUSTY WINDS AND DAMP CONDITIONS WILL ONLY ADD CONSIDERABLE
MORE CHILL. SOUNDS FUN...DOESN`T IT?

&&

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 245 AM EDT MON APR 20 2015

STILL SOME DISCREPANCIES
REGARDING JUST HOW LONG THIS SYSTEM LINGERS INTO THE END OF THE
WEEK...WITH THE GFS/GEFS/GEM NOTABLY SLOWER MOVING IT OUT THAN
RECENT ECMWF/UKMET RUNS. GIVEN UNCERTAINTIES...WILL SIMPLY RIDE WITH
INHERITED FORECAST...FEATURING SOME LINGERING LIGHT RAIN/SNOW
SHOWERS (AT LEAST FOR PARTS OF THE AREA) RIGHT THROUGH
FRIDAY...GIVING WAY TO A DRY WEEKEND. NO MATTER HOW FAST THIS SYSTEM
EXITS...AIRMASS RECOVERY WILL BE A SLOW ONE...SUGGESTING
TEMPERATURES REMAINING BELOW NORMAL RIGHT THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 145 PM EDT MON APR 20 2015

EXPECT IMPROVEMENT AT ALL SITES THIS EVENING INTO TONIGHT AS DRIER
AIR MOVES INTO THE AREA. CONDITIONS WILL THEN DETERIORATE TUE
MORNING AS ANOTHER ROUND OF MOISTURE MOVES IN WITH AN UPPER LEVEL
DISTURBANCE. EXACT TIMING AND MAGNITUDE OF DETERIORATING CONDITIONS
ON TUE IS UNCERTAIN AT THIS TIME.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
     LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LMZ341-
     342-344>346.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LSZ321-
     322.

&&

$$

NEAR TERM...MLR
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...JIT



000
FXUS63 KAPX 201745
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
ISSUED BY NATIONAL WEATHER SERVICE MARQUETTE MI
145 PM EDT MON APR 20 2015

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 245 AM EDT MON APR 20 2015

LOW PRESSURE CENTER HAS REACHED FAR SW LWR MICHIGAN EARLY THIS
MORNING. WIDESPREAD RAIN NORTH OF THE LOW CENTER HAS SPREAD ACROSS
OUR ENTIRE CWA...WITH ADDITIONAL WIDESPREAD RAIN SHOWER ACTIVITY
EXPANDING AROUND AND EAST OF THE LOW CENTER THANKS TO STRONG 700-500
MB OMEGA AND DEEP MOISTURE CONTINUING TO ADVECT INTO THE REGION.
BOTH THE LATEST NAM AND ECMWF SUGGEST THERE WILL BE A BRIEF DIMINISH
IN POP DURING LATE MORNING/EARLY AFTERNOON AS THE LOW CENTER REACHES
ERN UPR MICHIGAN. DEEP MOISTURE THEN QUICKLY WRAPS BACK INTO
MICHIGAN AS THE LOW CONTINUES NORTHWARD INTO CANADA BY LATE
AFTERNOON. WILL CERTAINLY KEEP CATEGORICAL POPS IN PLACE THRU EARLY
MORNING...WITH ONLY A MINOR DIMINISH IN POPS TO LIKELY ACROSS OUR
SRN CWA THRU THE DAY. ALL THUNDER CHANCES WILL STAY WELL SOUTH OF
MICHIGAN ALONG AND AHEAD OF THE ASSOCIATED WARM FRONT. TEMPS WILL BE
NOTICEABLY COOLER TODAY...WITH HIGH TEMPS RANGING FROM THE MID 40S
IN ERN UPR MICHIGAN TO THE UPPER 50S IN NE LWR MICHIGAN.

SRN EDGE OF WRAP AROUND MOISTURE WILL ALSO LIFT NORTHWARD AS THE
SURFACE LOW DEPARTS DEEP INTO CANADA TONIGHT. HIGHEST POPS (LIKELY)
WILL RESIDE ACROSS THE NRN TWO-THIRDS OF OUR CWA DURING THE EVENING
WHERE LIFT AND WRAP-AROUND MOISTURE WILL LINGER THE LONGEST. ALL
POPS WILL DIMINISH TO CHANCE OVERNIGHT. COLD AIR WRAPPING AROUND THE
DEPARTING LOW WILL DROP 850 MB TEMPS TO AROUND -3 TO -4 C TONIGHT.
WHILE THIS WILL NOT BE SUFFICIENTLY COLD (YET) TO ACTIVATE THE LAKES
TO PROVIDE LAKE ENHANCEMENT TO ONGOING SYNOPTIC PRECIP...BUT IT WILL
BE COLD ENOUGH TO BEGIN TO MIX SOME SNOW IN WITH THE ONGOING RAIN
EVENT DURING THE OVERNIGHT HOURS. EXPECT NO SNOW ACCUMULATION AS
SURFACE TEMPS BOTTOM OUT AT OR A FEW DEGREES ABOVE FREEZING.

&&

.SHORT TERM...(TUESDAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 245 AM EDT MON APR 20 2015

HIGH IMPACT WEATHER POTENTIAL: NOTHING SIGNIFICANT.

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: UNFORTUNATELY...NOW MUCH
TALKED ABOUT CHANGES TO A COOLER WEATHER REGIME ALREADY UNFOLDING AT
THIS EARLY HOUR...WITH ROBUST WEST NOAM RIDGE AMPLIFICATION AND
STRONG SHORTWAVE DIVING ON ITS FRONT SIDE INTO THE NORTHERN PLAINS.
THIS LATTER FEATURE WILL HELP CARVE OUT DEVELOPMENT OF ONE RATHER
IMPRESSIVE UPPER LEVEL LOW ACROSS THE FAR NORTHERN LAKES THROUGH THE
MIDDLE OF THE WEEK...WITH THE FORMER HELPING NEGATE ANY REAL KICKER
SYSTEM TO HELP BOOT THIS SYSTEM OUT. THIS SPELLS A RATHER PROLONGED
PERIOD OF COOL AND DAMP WEATHER...WITH SEVERAL OPPORTUNITIES TO SEE
A LEAST A LITTLE BIT OF SNOW BY THE TIME THIS WORK WEEK WRAPS UP
(QUELL THE EXCITEMENT :)).

PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE TRENDS
AND ADDRESSING PERIODIC PRECIP CHANCES AND TYPE.

DETAILS: CENTER OF UPPER LEVEL COLD CORE GYRE EXPECTED TO SLOWLY
MAKE ITS WAY EAST ACROSS LAKE SUPERIOR TO START THE SHORT TERM
PERIOD (TUESDAY)...ESSENTIALLY STALLING OUT JUST TO OUR NORTH RIGHT
THROUGH WEDNESDAY NIGHT. WHILE AT NO TIMES DOES FORCING SEEM
GREAT...SPOKES OF SUPPORT ROTATING AROUND PARENT SYSTEM COMBINING
WITH DEEP CYCLONIC MOISTURE RICH FLOW AND STEEP LOW/MID LEVEL LAPSE
RATES (H5 TEMPS STILL SLATED TO FLIRT WITH -30C) WILL DEFINITELY
SUPPORT THE THREAT FOR SHOWERS TUESDAY THROUGH WEDNESDAY NIGHT.
GIVEN LACK OF ANY DEEP LAYER TRIGGER...WOULD EXPECT GREATEST SHOWER
COVERAGE TO OCCUR DURING THE LATE MORNING/AFTERNOON HOURS WHEN LOW
LEVEL LAPSE RATES ARE MAXIMIZED. STILL HINTS OVER-RIDING AIRMASS MAY
BECOME JUST COLD ENOUGH TO ENTICE AT LEAST SOME MINOR LAKE
CONTRIBUTION LATE TUESDAY NIGHT INTO WEDNESDAY NIGHT. REAL MARGINAL
DELTA T/S (JUST FLIRTING WITH 13C) SHOULD NEGATE ANY SIGNIFICANT
RESPONSE...ALTHOUGH GOTTA ADMIT SUCH PERSISTENT WEST FLOW UP INTO
THE HIGHLANDS DOES RAISE AN EYEBROW OR TWO. INCREASINGLY COLD OFF
THE DECK THERMAL PROFILES AND STEEP LAPSE RATES DEFINITELY SUPPORTS
SNOW AND GRAUPEL MIXING IN WITH THE SHOWERS DURING THE DAYTIME HOURS
TUESDAY AND WEDNESDAY...WITH THE REAL POSSIBILITY ANY HEAVIER
SHOWERS WILL FALL AS MAINLY SNOW. OVERNIGHT PROFILES CONTINUE TO
SUPPORT MORE OF AN ALL SNOW ENVIRONMENT AS SURFACE BASED MELTING
LAYER IS NEARLY/COMPLETELY LOST. NOT EXPECTING ANY SIGNIFICANT
ACCUMULATIONS...ALTHOUGH WOULD NOT BE SURPRISED FOR THE GROUND TO
TURN WHITE BY WEDNESDAY MORNING (AN INCH OR SO)...ESPECIALLY WHERE
PERSISTENT UPSLOPE FLOW IS REALIZED INTO NORTHWEST LOWER.

AFTER THIS PAST WEEKS PLEASANT WEATHER...JUST GONNA FEEL DOWNRIGHT
CHILLY THROUGH MIDWEEK...WITH HIGHS BACK DOWN INTO THE UPPER 30S/40S
(COLDEST WEDNESDAY) AND OVERNIGHT LOWS A GOOD 10 OR SO DEGREES
COLDER. GUSTY WINDS AND DAMP CONDITIONS WILL ONLY ADD CONSIDERABLE
MORE CHILL. SOUNDS FUN...DOESN`T IT?

&&

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 245 AM EDT MON APR 20 2015

STILL SOME DISCREPANCIES
REGARDING JUST HOW LONG THIS SYSTEM LINGERS INTO THE END OF THE
WEEK...WITH THE GFS/GEFS/GEM NOTABLY SLOWER MOVING IT OUT THAN
RECENT ECMWF/UKMET RUNS. GIVEN UNCERTAINTIES...WILL SIMPLY RIDE WITH
INHERITED FORECAST...FEATURING SOME LINGERING LIGHT RAIN/SNOW
SHOWERS (AT LEAST FOR PARTS OF THE AREA) RIGHT THROUGH
FRIDAY...GIVING WAY TO A DRY WEEKEND. NO MATTER HOW FAST THIS SYSTEM
EXITS...AIRMASS RECOVERY WILL BE A SLOW ONE...SUGGESTING
TEMPERATURES REMAINING BELOW NORMAL RIGHT THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 145 PM EDT MON APR 20 2015

EXPECT IMPROVEMENT AT ALL SITES THIS EVENING INTO TONIGHT AS DRIER
AIR MOVES INTO THE AREA. CONDITIONS WILL THEN DETERIORATE TUE
MORNING AS ANOTHER ROUND OF MOISTURE MOVES IN WITH AN UPPER LEVEL
DISTURBANCE. EXACT TIMING AND MAGNITUDE OF DETERIORATING CONDITIONS
ON TUE IS UNCERTAIN AT THIS TIME.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
     LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LMZ341-
     342-344>346.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LSZ321-
     322.

&&

$$

NEAR TERM...MLR
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...JIT



000
FXUS63 KAPX 201745
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
ISSUED BY NATIONAL WEATHER SERVICE MARQUETTE MI
145 PM EDT MON APR 20 2015

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 245 AM EDT MON APR 20 2015

LOW PRESSURE CENTER HAS REACHED FAR SW LWR MICHIGAN EARLY THIS
MORNING. WIDESPREAD RAIN NORTH OF THE LOW CENTER HAS SPREAD ACROSS
OUR ENTIRE CWA...WITH ADDITIONAL WIDESPREAD RAIN SHOWER ACTIVITY
EXPANDING AROUND AND EAST OF THE LOW CENTER THANKS TO STRONG 700-500
MB OMEGA AND DEEP MOISTURE CONTINUING TO ADVECT INTO THE REGION.
BOTH THE LATEST NAM AND ECMWF SUGGEST THERE WILL BE A BRIEF DIMINISH
IN POP DURING LATE MORNING/EARLY AFTERNOON AS THE LOW CENTER REACHES
ERN UPR MICHIGAN. DEEP MOISTURE THEN QUICKLY WRAPS BACK INTO
MICHIGAN AS THE LOW CONTINUES NORTHWARD INTO CANADA BY LATE
AFTERNOON. WILL CERTAINLY KEEP CATEGORICAL POPS IN PLACE THRU EARLY
MORNING...WITH ONLY A MINOR DIMINISH IN POPS TO LIKELY ACROSS OUR
SRN CWA THRU THE DAY. ALL THUNDER CHANCES WILL STAY WELL SOUTH OF
MICHIGAN ALONG AND AHEAD OF THE ASSOCIATED WARM FRONT. TEMPS WILL BE
NOTICEABLY COOLER TODAY...WITH HIGH TEMPS RANGING FROM THE MID 40S
IN ERN UPR MICHIGAN TO THE UPPER 50S IN NE LWR MICHIGAN.

SRN EDGE OF WRAP AROUND MOISTURE WILL ALSO LIFT NORTHWARD AS THE
SURFACE LOW DEPARTS DEEP INTO CANADA TONIGHT. HIGHEST POPS (LIKELY)
WILL RESIDE ACROSS THE NRN TWO-THIRDS OF OUR CWA DURING THE EVENING
WHERE LIFT AND WRAP-AROUND MOISTURE WILL LINGER THE LONGEST. ALL
POPS WILL DIMINISH TO CHANCE OVERNIGHT. COLD AIR WRAPPING AROUND THE
DEPARTING LOW WILL DROP 850 MB TEMPS TO AROUND -3 TO -4 C TONIGHT.
WHILE THIS WILL NOT BE SUFFICIENTLY COLD (YET) TO ACTIVATE THE LAKES
TO PROVIDE LAKE ENHANCEMENT TO ONGOING SYNOPTIC PRECIP...BUT IT WILL
BE COLD ENOUGH TO BEGIN TO MIX SOME SNOW IN WITH THE ONGOING RAIN
EVENT DURING THE OVERNIGHT HOURS. EXPECT NO SNOW ACCUMULATION AS
SURFACE TEMPS BOTTOM OUT AT OR A FEW DEGREES ABOVE FREEZING.

&&

.SHORT TERM...(TUESDAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 245 AM EDT MON APR 20 2015

HIGH IMPACT WEATHER POTENTIAL: NOTHING SIGNIFICANT.

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: UNFORTUNATELY...NOW MUCH
TALKED ABOUT CHANGES TO A COOLER WEATHER REGIME ALREADY UNFOLDING AT
THIS EARLY HOUR...WITH ROBUST WEST NOAM RIDGE AMPLIFICATION AND
STRONG SHORTWAVE DIVING ON ITS FRONT SIDE INTO THE NORTHERN PLAINS.
THIS LATTER FEATURE WILL HELP CARVE OUT DEVELOPMENT OF ONE RATHER
IMPRESSIVE UPPER LEVEL LOW ACROSS THE FAR NORTHERN LAKES THROUGH THE
MIDDLE OF THE WEEK...WITH THE FORMER HELPING NEGATE ANY REAL KICKER
SYSTEM TO HELP BOOT THIS SYSTEM OUT. THIS SPELLS A RATHER PROLONGED
PERIOD OF COOL AND DAMP WEATHER...WITH SEVERAL OPPORTUNITIES TO SEE
A LEAST A LITTLE BIT OF SNOW BY THE TIME THIS WORK WEEK WRAPS UP
(QUELL THE EXCITEMENT :)).

PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE TRENDS
AND ADDRESSING PERIODIC PRECIP CHANCES AND TYPE.

DETAILS: CENTER OF UPPER LEVEL COLD CORE GYRE EXPECTED TO SLOWLY
MAKE ITS WAY EAST ACROSS LAKE SUPERIOR TO START THE SHORT TERM
PERIOD (TUESDAY)...ESSENTIALLY STALLING OUT JUST TO OUR NORTH RIGHT
THROUGH WEDNESDAY NIGHT. WHILE AT NO TIMES DOES FORCING SEEM
GREAT...SPOKES OF SUPPORT ROTATING AROUND PARENT SYSTEM COMBINING
WITH DEEP CYCLONIC MOISTURE RICH FLOW AND STEEP LOW/MID LEVEL LAPSE
RATES (H5 TEMPS STILL SLATED TO FLIRT WITH -30C) WILL DEFINITELY
SUPPORT THE THREAT FOR SHOWERS TUESDAY THROUGH WEDNESDAY NIGHT.
GIVEN LACK OF ANY DEEP LAYER TRIGGER...WOULD EXPECT GREATEST SHOWER
COVERAGE TO OCCUR DURING THE LATE MORNING/AFTERNOON HOURS WHEN LOW
LEVEL LAPSE RATES ARE MAXIMIZED. STILL HINTS OVER-RIDING AIRMASS MAY
BECOME JUST COLD ENOUGH TO ENTICE AT LEAST SOME MINOR LAKE
CONTRIBUTION LATE TUESDAY NIGHT INTO WEDNESDAY NIGHT. REAL MARGINAL
DELTA T/S (JUST FLIRTING WITH 13C) SHOULD NEGATE ANY SIGNIFICANT
RESPONSE...ALTHOUGH GOTTA ADMIT SUCH PERSISTENT WEST FLOW UP INTO
THE HIGHLANDS DOES RAISE AN EYEBROW OR TWO. INCREASINGLY COLD OFF
THE DECK THERMAL PROFILES AND STEEP LAPSE RATES DEFINITELY SUPPORTS
SNOW AND GRAUPEL MIXING IN WITH THE SHOWERS DURING THE DAYTIME HOURS
TUESDAY AND WEDNESDAY...WITH THE REAL POSSIBILITY ANY HEAVIER
SHOWERS WILL FALL AS MAINLY SNOW. OVERNIGHT PROFILES CONTINUE TO
SUPPORT MORE OF AN ALL SNOW ENVIRONMENT AS SURFACE BASED MELTING
LAYER IS NEARLY/COMPLETELY LOST. NOT EXPECTING ANY SIGNIFICANT
ACCUMULATIONS...ALTHOUGH WOULD NOT BE SURPRISED FOR THE GROUND TO
TURN WHITE BY WEDNESDAY MORNING (AN INCH OR SO)...ESPECIALLY WHERE
PERSISTENT UPSLOPE FLOW IS REALIZED INTO NORTHWEST LOWER.

AFTER THIS PAST WEEKS PLEASANT WEATHER...JUST GONNA FEEL DOWNRIGHT
CHILLY THROUGH MIDWEEK...WITH HIGHS BACK DOWN INTO THE UPPER 30S/40S
(COLDEST WEDNESDAY) AND OVERNIGHT LOWS A GOOD 10 OR SO DEGREES
COLDER. GUSTY WINDS AND DAMP CONDITIONS WILL ONLY ADD CONSIDERABLE
MORE CHILL. SOUNDS FUN...DOESN`T IT?

&&

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 245 AM EDT MON APR 20 2015

STILL SOME DISCREPANCIES
REGARDING JUST HOW LONG THIS SYSTEM LINGERS INTO THE END OF THE
WEEK...WITH THE GFS/GEFS/GEM NOTABLY SLOWER MOVING IT OUT THAN
RECENT ECMWF/UKMET RUNS. GIVEN UNCERTAINTIES...WILL SIMPLY RIDE WITH
INHERITED FORECAST...FEATURING SOME LINGERING LIGHT RAIN/SNOW
SHOWERS (AT LEAST FOR PARTS OF THE AREA) RIGHT THROUGH
FRIDAY...GIVING WAY TO A DRY WEEKEND. NO MATTER HOW FAST THIS SYSTEM
EXITS...AIRMASS RECOVERY WILL BE A SLOW ONE...SUGGESTING
TEMPERATURES REMAINING BELOW NORMAL RIGHT THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 145 PM EDT MON APR 20 2015

EXPECT IMPROVEMENT AT ALL SITES THIS EVENING INTO TONIGHT AS DRIER
AIR MOVES INTO THE AREA. CONDITIONS WILL THEN DETERIORATE TUE
MORNING AS ANOTHER ROUND OF MOISTURE MOVES IN WITH AN UPPER LEVEL
DISTURBANCE. EXACT TIMING AND MAGNITUDE OF DETERIORATING CONDITIONS
ON TUE IS UNCERTAIN AT THIS TIME.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
     LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LMZ341-
     342-344>346.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LSZ321-
     322.

&&

$$

NEAR TERM...MLR
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...JIT




000
FXUS63 KMQT 201736
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
136 PM EDT MON APR 20 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT MON APR 20 2015

UPPER AIR PATTERN CONSISTS OF A ELONGATED 500 MB TROUGH WITH SEVERAL
SHORTWAVES EMBEDDED IN IT. THE SHORTWAVE OVER LOWER MICHIGAN WILL BE
SPREADING PCPN UP INTO THE CWA THIS MORNING WHILE ANOTHER SHORTWAVE
OVER THE RED RIVER VALLEY OF THE NORTH WILL PUT PCPN IN OVER THE FAR
WEST THIS MORNING. BOTH THESE SHORTWAVES WILL COMBINE OVER THE AREA
AND CAUSE SOME WIDESPREAD PCPN THIS MORNING OVER THE CWA. UPPER
TROUGH SLOWLY MOVES EAST WITH A 500 MB LOW MOVING OVER THE U.P. LATE
TONIGHT. NAM SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE OVER THE CWA THIS MORNING. THE DEEPER MOISTURE REMAIN
OVER THE AREA THROUGH TONIGHT WHILE THE Q-VECTOR CONVERGENCE WEAKENS
AND MOVES OUT BY THIS EVENING BEFORE MOVING BACK IN LATE TONIGHT
WITH THE 500 MB LOW. GFS AND ECMWF SHOW ABOUT THE SAME THING AS
WELL.

HAD TO HANG ONTO THE DRIER AIR ACROSS THE CENTRAL CWA A BIT LONGER
THIS MORNING AND CUT THE QPF AMOUNTS BECAUSE OF THIS. DID GO WITH A
COMBO OF WET BULB HEIGHTS AND WARM TEMPERATURES ALOFT TO DETERMINE
SNOW FOR THIS FORECAST AND LOOKS LIKE THE ACCUMULATING SNOW WILL BE
TONIGHT WHERE UP TO 2 INCHES COULD FALL ACROSS THE WESTERN
HIGHLANDS. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
TEMPERATURE FORECAST AND WENT WITH CATEGORICAL POPS FOR TODAY FOR
THE CWA AND THEN LIKELY POPS IN NORTHWEST LAKE EFFECT BELTS TONIGHT
AND KEPT SOME SLIGHT CHANCE POPS IN THE FAR SOUTH DUE TO THE UPPER
LOW MOVING INTO THE AREA AND WRAPAROUND PCPN IN THE AREA.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 507 AM EDT MON APR 20 2015

COLDER...WITH LITTLE BREAK IN IN THE NEAR FUTURE. THE BEST CHANCE OF
LIGHT PRECIP WILL BE ALONG THE LAKE SUPERIOR SHORELINE.

AT 12Z TUESDAY THE SFC LOW WILL HAVE SHIFTED TO JUST W OF JAMES
BAY...WITH A TROUGH/SECONDARY COLD FRONT EXTENDING OVER CENTRAL LAKE
SUPERIOR AND CENTRAL UPPER MI. 850MB TEMPS AHEAD OF THE TROUGH WILL
AVERAGE AROUND -4C...AND FALL TO AROUND -7C BY THE END OF THE DAY
BEHIND THE TROUGH. THIS WILL COINCIDE WITH THE PASSAGE OF THE LARGE
500MB LOW...CENTERED OVER THE CWA TUESDAY. THE SIZABLE TROUGH WILL
ENCOMPASS E MT THROUGH THE GULF STATES...AND BACK UP THROUGH THE NEW
ENGLAND STATES.

THE 500MB LOW WILL NOT MOVE MUCH...ONLY TO E ONTARIO BY THURSDAY
MORNING. THIS WILL BE SIMILAR TO THE SFC LOW WHICH WILL ONLY SHIFT
TO FAR W ONTARIO DURING THE SAME TIME. LOOK FOR PERSISTENT NW WINDS
AND 850MB TEMPS OF -8 TO -12C.

THE 500MB LOW WILL CONTINUE ITS E PROGRESSION THURSDAY NIGHT THROUGH
FRIDAY...MOVING ACROSS S QUEBEC. WHILE A WEAK RIDGE WILL ATTEMPT TO
BUILD OVER FAR W LAKE SUPERIOR/UPPER MI...THE TROUGH WILL STILL
REMAIN OVER THE E. WHILE THE SFC LOW INITIALLY SHIFTS TO SE QUEBEC
EARLY THURSDAY EVENING...IT LOOKS TO SHIFT BACK W DURING THE DAY
FRIDAY /PARTICULARLY OFF THE GFS SOLUTION/.

THERE LOOKS TO BE SOME DISCREPANCIES IN THE HANDLING OF THE 500MB
LOW FOR THE LATTER HALF OF THE WEEKEND BY THE 00Z MODEL RUNS. WHILE
THE ECMWF PUSHES A RIDGE OVER THE UPPER GREAT LAKES SATURDAY AND
SUNDAY...THE GFS KEEPS THE TROUGH IN PLACE. AS A RESULT...FEW
CHANGES WERE MADE TO THE ONGOING FCST FOR THE WEEKEND. TEMPS MAY
RISE AROUND 5F SUNDAY COMPARED TO SATURDAY...BUT WAS LACKING
CONFIDENCE TO DO MUCH MORE THAN THAT. THE ECMWF SOLUTION WOULD BRING
850MB TEMPS BACK TO -2C BY SATURDAY AFTERNOON WITH THAT RIDGE
BUILDING IN. HOWEVER...THE GFS IS STILL AROUND -8C.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 131 PM EDT MON APR 20 2015

AREA OF DEEPER MSTR ASSOCIATED WITH BAND OF SHARPER FORCING WL BRING
A PERIOD OF STEADY SN TO CMX THRU THIS AFTN ALONG WITH LIFR
CONDITIONS. GUSTY W WINDS TO NEAR 30 KTS WL ALSO IMPACT THIS MORE
EXPOSED LOCATION. THE AREA OF PCPN WL EXIT IWD SOON AFTER TAF
ISSUANCE...SO EXPECT AN IMPROVEMENT THERE FM IFR TO MVFR WITH THE
ARRIVAL OF SOME DRIER AIR/SUBSIDENCE. SINCE THE BAND OF HEAVIER PCPN
IS LIKELY TO REMAIN TO THE W OF SAW...THERE SHOULD BE MVFR CIGS WITH
ONLY SOME OCNL -SHRA IN THE PRESENCE OF A DOWNSLOPE WIND COMPONENT.
FOR THIS EVNG...MVFR CONDITIONS SHOULD BE THE RULE WITH MVFR CIGS
AND ONLY SOME SCT LIGHT -SHSN OR -SHSNRA. BUT THE APRCH OF ANOTHER
DISTURBANCE/LO PRES TROF LATE TNGT SHOULD RESULT IN DETERIORATING
CONDITIONS AGAIN WITH IFR CONDITIONS DVLPG AT IWD AND CMX. DOWNSLOPE
WINDS AT SAW WL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO IWD AND CMX BY LATE MRNG ON TUE.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT MON APR 20 2015

AS A LOW LIFTS THROUGH THE SOO THIS AFTERNOON...WINDS WILL BACK TO
THE WEST-NORTHWEST THIS AFTERNOON. WITH THE LOW BECOMING STATIONARY
JUST TO THE SOUTHWEST OF JAMES BAY TONIGHT THROUGH
WEDNESDAY...PERSISTENT NORTHWESTERLY WINDS OF 20-30KTS ARE EXPECTED.
ALTHOUGH THE LOW WILL WEAKEN AND MOVE EAST ACROSS QUEBEC WEDNESDAY
NIGHT INTO THURSDAY...THE NORTHWEST WINDS UP TO 25KTS WILL PERSIST
AS A RIDGE MOVES INTO THE NORTHERN PLAINS. THE WINDS DIMINISH THEN
BELOW 20 KNOTS BY THURSDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...KF
AVIATION...KC
MARINE...07




000
FXUS63 KMQT 201736
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
136 PM EDT MON APR 20 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT MON APR 20 2015

UPPER AIR PATTERN CONSISTS OF A ELONGATED 500 MB TROUGH WITH SEVERAL
SHORTWAVES EMBEDDED IN IT. THE SHORTWAVE OVER LOWER MICHIGAN WILL BE
SPREADING PCPN UP INTO THE CWA THIS MORNING WHILE ANOTHER SHORTWAVE
OVER THE RED RIVER VALLEY OF THE NORTH WILL PUT PCPN IN OVER THE FAR
WEST THIS MORNING. BOTH THESE SHORTWAVES WILL COMBINE OVER THE AREA
AND CAUSE SOME WIDESPREAD PCPN THIS MORNING OVER THE CWA. UPPER
TROUGH SLOWLY MOVES EAST WITH A 500 MB LOW MOVING OVER THE U.P. LATE
TONIGHT. NAM SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE OVER THE CWA THIS MORNING. THE DEEPER MOISTURE REMAIN
OVER THE AREA THROUGH TONIGHT WHILE THE Q-VECTOR CONVERGENCE WEAKENS
AND MOVES OUT BY THIS EVENING BEFORE MOVING BACK IN LATE TONIGHT
WITH THE 500 MB LOW. GFS AND ECMWF SHOW ABOUT THE SAME THING AS
WELL.

HAD TO HANG ONTO THE DRIER AIR ACROSS THE CENTRAL CWA A BIT LONGER
THIS MORNING AND CUT THE QPF AMOUNTS BECAUSE OF THIS. DID GO WITH A
COMBO OF WET BULB HEIGHTS AND WARM TEMPERATURES ALOFT TO DETERMINE
SNOW FOR THIS FORECAST AND LOOKS LIKE THE ACCUMULATING SNOW WILL BE
TONIGHT WHERE UP TO 2 INCHES COULD FALL ACROSS THE WESTERN
HIGHLANDS. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
TEMPERATURE FORECAST AND WENT WITH CATEGORICAL POPS FOR TODAY FOR
THE CWA AND THEN LIKELY POPS IN NORTHWEST LAKE EFFECT BELTS TONIGHT
AND KEPT SOME SLIGHT CHANCE POPS IN THE FAR SOUTH DUE TO THE UPPER
LOW MOVING INTO THE AREA AND WRAPAROUND PCPN IN THE AREA.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 507 AM EDT MON APR 20 2015

COLDER...WITH LITTLE BREAK IN IN THE NEAR FUTURE. THE BEST CHANCE OF
LIGHT PRECIP WILL BE ALONG THE LAKE SUPERIOR SHORELINE.

AT 12Z TUESDAY THE SFC LOW WILL HAVE SHIFTED TO JUST W OF JAMES
BAY...WITH A TROUGH/SECONDARY COLD FRONT EXTENDING OVER CENTRAL LAKE
SUPERIOR AND CENTRAL UPPER MI. 850MB TEMPS AHEAD OF THE TROUGH WILL
AVERAGE AROUND -4C...AND FALL TO AROUND -7C BY THE END OF THE DAY
BEHIND THE TROUGH. THIS WILL COINCIDE WITH THE PASSAGE OF THE LARGE
500MB LOW...CENTERED OVER THE CWA TUESDAY. THE SIZABLE TROUGH WILL
ENCOMPASS E MT THROUGH THE GULF STATES...AND BACK UP THROUGH THE NEW
ENGLAND STATES.

THE 500MB LOW WILL NOT MOVE MUCH...ONLY TO E ONTARIO BY THURSDAY
MORNING. THIS WILL BE SIMILAR TO THE SFC LOW WHICH WILL ONLY SHIFT
TO FAR W ONTARIO DURING THE SAME TIME. LOOK FOR PERSISTENT NW WINDS
AND 850MB TEMPS OF -8 TO -12C.

THE 500MB LOW WILL CONTINUE ITS E PROGRESSION THURSDAY NIGHT THROUGH
FRIDAY...MOVING ACROSS S QUEBEC. WHILE A WEAK RIDGE WILL ATTEMPT TO
BUILD OVER FAR W LAKE SUPERIOR/UPPER MI...THE TROUGH WILL STILL
REMAIN OVER THE E. WHILE THE SFC LOW INITIALLY SHIFTS TO SE QUEBEC
EARLY THURSDAY EVENING...IT LOOKS TO SHIFT BACK W DURING THE DAY
FRIDAY /PARTICULARLY OFF THE GFS SOLUTION/.

THERE LOOKS TO BE SOME DISCREPANCIES IN THE HANDLING OF THE 500MB
LOW FOR THE LATTER HALF OF THE WEEKEND BY THE 00Z MODEL RUNS. WHILE
THE ECMWF PUSHES A RIDGE OVER THE UPPER GREAT LAKES SATURDAY AND
SUNDAY...THE GFS KEEPS THE TROUGH IN PLACE. AS A RESULT...FEW
CHANGES WERE MADE TO THE ONGOING FCST FOR THE WEEKEND. TEMPS MAY
RISE AROUND 5F SUNDAY COMPARED TO SATURDAY...BUT WAS LACKING
CONFIDENCE TO DO MUCH MORE THAN THAT. THE ECMWF SOLUTION WOULD BRING
850MB TEMPS BACK TO -2C BY SATURDAY AFTERNOON WITH THAT RIDGE
BUILDING IN. HOWEVER...THE GFS IS STILL AROUND -8C.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 131 PM EDT MON APR 20 2015

AREA OF DEEPER MSTR ASSOCIATED WITH BAND OF SHARPER FORCING WL BRING
A PERIOD OF STEADY SN TO CMX THRU THIS AFTN ALONG WITH LIFR
CONDITIONS. GUSTY W WINDS TO NEAR 30 KTS WL ALSO IMPACT THIS MORE
EXPOSED LOCATION. THE AREA OF PCPN WL EXIT IWD SOON AFTER TAF
ISSUANCE...SO EXPECT AN IMPROVEMENT THERE FM IFR TO MVFR WITH THE
ARRIVAL OF SOME DRIER AIR/SUBSIDENCE. SINCE THE BAND OF HEAVIER PCPN
IS LIKELY TO REMAIN TO THE W OF SAW...THERE SHOULD BE MVFR CIGS WITH
ONLY SOME OCNL -SHRA IN THE PRESENCE OF A DOWNSLOPE WIND COMPONENT.
FOR THIS EVNG...MVFR CONDITIONS SHOULD BE THE RULE WITH MVFR CIGS
AND ONLY SOME SCT LIGHT -SHSN OR -SHSNRA. BUT THE APRCH OF ANOTHER
DISTURBANCE/LO PRES TROF LATE TNGT SHOULD RESULT IN DETERIORATING
CONDITIONS AGAIN WITH IFR CONDITIONS DVLPG AT IWD AND CMX. DOWNSLOPE
WINDS AT SAW WL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO IWD AND CMX BY LATE MRNG ON TUE.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT MON APR 20 2015

AS A LOW LIFTS THROUGH THE SOO THIS AFTERNOON...WINDS WILL BACK TO
THE WEST-NORTHWEST THIS AFTERNOON. WITH THE LOW BECOMING STATIONARY
JUST TO THE SOUTHWEST OF JAMES BAY TONIGHT THROUGH
WEDNESDAY...PERSISTENT NORTHWESTERLY WINDS OF 20-30KTS ARE EXPECTED.
ALTHOUGH THE LOW WILL WEAKEN AND MOVE EAST ACROSS QUEBEC WEDNESDAY
NIGHT INTO THURSDAY...THE NORTHWEST WINDS UP TO 25KTS WILL PERSIST
AS A RIDGE MOVES INTO THE NORTHERN PLAINS. THE WINDS DIMINISH THEN
BELOW 20 KNOTS BY THURSDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...KF
AVIATION...KC
MARINE...07




000
FXUS63 KMQT 201736
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
136 PM EDT MON APR 20 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT MON APR 20 2015

UPPER AIR PATTERN CONSISTS OF A ELONGATED 500 MB TROUGH WITH SEVERAL
SHORTWAVES EMBEDDED IN IT. THE SHORTWAVE OVER LOWER MICHIGAN WILL BE
SPREADING PCPN UP INTO THE CWA THIS MORNING WHILE ANOTHER SHORTWAVE
OVER THE RED RIVER VALLEY OF THE NORTH WILL PUT PCPN IN OVER THE FAR
WEST THIS MORNING. BOTH THESE SHORTWAVES WILL COMBINE OVER THE AREA
AND CAUSE SOME WIDESPREAD PCPN THIS MORNING OVER THE CWA. UPPER
TROUGH SLOWLY MOVES EAST WITH A 500 MB LOW MOVING OVER THE U.P. LATE
TONIGHT. NAM SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE OVER THE CWA THIS MORNING. THE DEEPER MOISTURE REMAIN
OVER THE AREA THROUGH TONIGHT WHILE THE Q-VECTOR CONVERGENCE WEAKENS
AND MOVES OUT BY THIS EVENING BEFORE MOVING BACK IN LATE TONIGHT
WITH THE 500 MB LOW. GFS AND ECMWF SHOW ABOUT THE SAME THING AS
WELL.

HAD TO HANG ONTO THE DRIER AIR ACROSS THE CENTRAL CWA A BIT LONGER
THIS MORNING AND CUT THE QPF AMOUNTS BECAUSE OF THIS. DID GO WITH A
COMBO OF WET BULB HEIGHTS AND WARM TEMPERATURES ALOFT TO DETERMINE
SNOW FOR THIS FORECAST AND LOOKS LIKE THE ACCUMULATING SNOW WILL BE
TONIGHT WHERE UP TO 2 INCHES COULD FALL ACROSS THE WESTERN
HIGHLANDS. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
TEMPERATURE FORECAST AND WENT WITH CATEGORICAL POPS FOR TODAY FOR
THE CWA AND THEN LIKELY POPS IN NORTHWEST LAKE EFFECT BELTS TONIGHT
AND KEPT SOME SLIGHT CHANCE POPS IN THE FAR SOUTH DUE TO THE UPPER
LOW MOVING INTO THE AREA AND WRAPAROUND PCPN IN THE AREA.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 507 AM EDT MON APR 20 2015

COLDER...WITH LITTLE BREAK IN IN THE NEAR FUTURE. THE BEST CHANCE OF
LIGHT PRECIP WILL BE ALONG THE LAKE SUPERIOR SHORELINE.

AT 12Z TUESDAY THE SFC LOW WILL HAVE SHIFTED TO JUST W OF JAMES
BAY...WITH A TROUGH/SECONDARY COLD FRONT EXTENDING OVER CENTRAL LAKE
SUPERIOR AND CENTRAL UPPER MI. 850MB TEMPS AHEAD OF THE TROUGH WILL
AVERAGE AROUND -4C...AND FALL TO AROUND -7C BY THE END OF THE DAY
BEHIND THE TROUGH. THIS WILL COINCIDE WITH THE PASSAGE OF THE LARGE
500MB LOW...CENTERED OVER THE CWA TUESDAY. THE SIZABLE TROUGH WILL
ENCOMPASS E MT THROUGH THE GULF STATES...AND BACK UP THROUGH THE NEW
ENGLAND STATES.

THE 500MB LOW WILL NOT MOVE MUCH...ONLY TO E ONTARIO BY THURSDAY
MORNING. THIS WILL BE SIMILAR TO THE SFC LOW WHICH WILL ONLY SHIFT
TO FAR W ONTARIO DURING THE SAME TIME. LOOK FOR PERSISTENT NW WINDS
AND 850MB TEMPS OF -8 TO -12C.

THE 500MB LOW WILL CONTINUE ITS E PROGRESSION THURSDAY NIGHT THROUGH
FRIDAY...MOVING ACROSS S QUEBEC. WHILE A WEAK RIDGE WILL ATTEMPT TO
BUILD OVER FAR W LAKE SUPERIOR/UPPER MI...THE TROUGH WILL STILL
REMAIN OVER THE E. WHILE THE SFC LOW INITIALLY SHIFTS TO SE QUEBEC
EARLY THURSDAY EVENING...IT LOOKS TO SHIFT BACK W DURING THE DAY
FRIDAY /PARTICULARLY OFF THE GFS SOLUTION/.

THERE LOOKS TO BE SOME DISCREPANCIES IN THE HANDLING OF THE 500MB
LOW FOR THE LATTER HALF OF THE WEEKEND BY THE 00Z MODEL RUNS. WHILE
THE ECMWF PUSHES A RIDGE OVER THE UPPER GREAT LAKES SATURDAY AND
SUNDAY...THE GFS KEEPS THE TROUGH IN PLACE. AS A RESULT...FEW
CHANGES WERE MADE TO THE ONGOING FCST FOR THE WEEKEND. TEMPS MAY
RISE AROUND 5F SUNDAY COMPARED TO SATURDAY...BUT WAS LACKING
CONFIDENCE TO DO MUCH MORE THAN THAT. THE ECMWF SOLUTION WOULD BRING
850MB TEMPS BACK TO -2C BY SATURDAY AFTERNOON WITH THAT RIDGE
BUILDING IN. HOWEVER...THE GFS IS STILL AROUND -8C.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 131 PM EDT MON APR 20 2015

AREA OF DEEPER MSTR ASSOCIATED WITH BAND OF SHARPER FORCING WL BRING
A PERIOD OF STEADY SN TO CMX THRU THIS AFTN ALONG WITH LIFR
CONDITIONS. GUSTY W WINDS TO NEAR 30 KTS WL ALSO IMPACT THIS MORE
EXPOSED LOCATION. THE AREA OF PCPN WL EXIT IWD SOON AFTER TAF
ISSUANCE...SO EXPECT AN IMPROVEMENT THERE FM IFR TO MVFR WITH THE
ARRIVAL OF SOME DRIER AIR/SUBSIDENCE. SINCE THE BAND OF HEAVIER PCPN
IS LIKELY TO REMAIN TO THE W OF SAW...THERE SHOULD BE MVFR CIGS WITH
ONLY SOME OCNL -SHRA IN THE PRESENCE OF A DOWNSLOPE WIND COMPONENT.
FOR THIS EVNG...MVFR CONDITIONS SHOULD BE THE RULE WITH MVFR CIGS
AND ONLY SOME SCT LIGHT -SHSN OR -SHSNRA. BUT THE APRCH OF ANOTHER
DISTURBANCE/LO PRES TROF LATE TNGT SHOULD RESULT IN DETERIORATING
CONDITIONS AGAIN WITH IFR CONDITIONS DVLPG AT IWD AND CMX. DOWNSLOPE
WINDS AT SAW WL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO IWD AND CMX BY LATE MRNG ON TUE.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT MON APR 20 2015

AS A LOW LIFTS THROUGH THE SOO THIS AFTERNOON...WINDS WILL BACK TO
THE WEST-NORTHWEST THIS AFTERNOON. WITH THE LOW BECOMING STATIONARY
JUST TO THE SOUTHWEST OF JAMES BAY TONIGHT THROUGH
WEDNESDAY...PERSISTENT NORTHWESTERLY WINDS OF 20-30KTS ARE EXPECTED.
ALTHOUGH THE LOW WILL WEAKEN AND MOVE EAST ACROSS QUEBEC WEDNESDAY
NIGHT INTO THURSDAY...THE NORTHWEST WINDS UP TO 25KTS WILL PERSIST
AS A RIDGE MOVES INTO THE NORTHERN PLAINS. THE WINDS DIMINISH THEN
BELOW 20 KNOTS BY THURSDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...KF
AVIATION...KC
MARINE...07




000
FXUS63 KMQT 201736
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
136 PM EDT MON APR 20 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT MON APR 20 2015

UPPER AIR PATTERN CONSISTS OF A ELONGATED 500 MB TROUGH WITH SEVERAL
SHORTWAVES EMBEDDED IN IT. THE SHORTWAVE OVER LOWER MICHIGAN WILL BE
SPREADING PCPN UP INTO THE CWA THIS MORNING WHILE ANOTHER SHORTWAVE
OVER THE RED RIVER VALLEY OF THE NORTH WILL PUT PCPN IN OVER THE FAR
WEST THIS MORNING. BOTH THESE SHORTWAVES WILL COMBINE OVER THE AREA
AND CAUSE SOME WIDESPREAD PCPN THIS MORNING OVER THE CWA. UPPER
TROUGH SLOWLY MOVES EAST WITH A 500 MB LOW MOVING OVER THE U.P. LATE
TONIGHT. NAM SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE OVER THE CWA THIS MORNING. THE DEEPER MOISTURE REMAIN
OVER THE AREA THROUGH TONIGHT WHILE THE Q-VECTOR CONVERGENCE WEAKENS
AND MOVES OUT BY THIS EVENING BEFORE MOVING BACK IN LATE TONIGHT
WITH THE 500 MB LOW. GFS AND ECMWF SHOW ABOUT THE SAME THING AS
WELL.

HAD TO HANG ONTO THE DRIER AIR ACROSS THE CENTRAL CWA A BIT LONGER
THIS MORNING AND CUT THE QPF AMOUNTS BECAUSE OF THIS. DID GO WITH A
COMBO OF WET BULB HEIGHTS AND WARM TEMPERATURES ALOFT TO DETERMINE
SNOW FOR THIS FORECAST AND LOOKS LIKE THE ACCUMULATING SNOW WILL BE
TONIGHT WHERE UP TO 2 INCHES COULD FALL ACROSS THE WESTERN
HIGHLANDS. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
TEMPERATURE FORECAST AND WENT WITH CATEGORICAL POPS FOR TODAY FOR
THE CWA AND THEN LIKELY POPS IN NORTHWEST LAKE EFFECT BELTS TONIGHT
AND KEPT SOME SLIGHT CHANCE POPS IN THE FAR SOUTH DUE TO THE UPPER
LOW MOVING INTO THE AREA AND WRAPAROUND PCPN IN THE AREA.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 507 AM EDT MON APR 20 2015

COLDER...WITH LITTLE BREAK IN IN THE NEAR FUTURE. THE BEST CHANCE OF
LIGHT PRECIP WILL BE ALONG THE LAKE SUPERIOR SHORELINE.

AT 12Z TUESDAY THE SFC LOW WILL HAVE SHIFTED TO JUST W OF JAMES
BAY...WITH A TROUGH/SECONDARY COLD FRONT EXTENDING OVER CENTRAL LAKE
SUPERIOR AND CENTRAL UPPER MI. 850MB TEMPS AHEAD OF THE TROUGH WILL
AVERAGE AROUND -4C...AND FALL TO AROUND -7C BY THE END OF THE DAY
BEHIND THE TROUGH. THIS WILL COINCIDE WITH THE PASSAGE OF THE LARGE
500MB LOW...CENTERED OVER THE CWA TUESDAY. THE SIZABLE TROUGH WILL
ENCOMPASS E MT THROUGH THE GULF STATES...AND BACK UP THROUGH THE NEW
ENGLAND STATES.

THE 500MB LOW WILL NOT MOVE MUCH...ONLY TO E ONTARIO BY THURSDAY
MORNING. THIS WILL BE SIMILAR TO THE SFC LOW WHICH WILL ONLY SHIFT
TO FAR W ONTARIO DURING THE SAME TIME. LOOK FOR PERSISTENT NW WINDS
AND 850MB TEMPS OF -8 TO -12C.

THE 500MB LOW WILL CONTINUE ITS E PROGRESSION THURSDAY NIGHT THROUGH
FRIDAY...MOVING ACROSS S QUEBEC. WHILE A WEAK RIDGE WILL ATTEMPT TO
BUILD OVER FAR W LAKE SUPERIOR/UPPER MI...THE TROUGH WILL STILL
REMAIN OVER THE E. WHILE THE SFC LOW INITIALLY SHIFTS TO SE QUEBEC
EARLY THURSDAY EVENING...IT LOOKS TO SHIFT BACK W DURING THE DAY
FRIDAY /PARTICULARLY OFF THE GFS SOLUTION/.

THERE LOOKS TO BE SOME DISCREPANCIES IN THE HANDLING OF THE 500MB
LOW FOR THE LATTER HALF OF THE WEEKEND BY THE 00Z MODEL RUNS. WHILE
THE ECMWF PUSHES A RIDGE OVER THE UPPER GREAT LAKES SATURDAY AND
SUNDAY...THE GFS KEEPS THE TROUGH IN PLACE. AS A RESULT...FEW
CHANGES WERE MADE TO THE ONGOING FCST FOR THE WEEKEND. TEMPS MAY
RISE AROUND 5F SUNDAY COMPARED TO SATURDAY...BUT WAS LACKING
CONFIDENCE TO DO MUCH MORE THAN THAT. THE ECMWF SOLUTION WOULD BRING
850MB TEMPS BACK TO -2C BY SATURDAY AFTERNOON WITH THAT RIDGE
BUILDING IN. HOWEVER...THE GFS IS STILL AROUND -8C.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 131 PM EDT MON APR 20 2015

AREA OF DEEPER MSTR ASSOCIATED WITH BAND OF SHARPER FORCING WL BRING
A PERIOD OF STEADY SN TO CMX THRU THIS AFTN ALONG WITH LIFR
CONDITIONS. GUSTY W WINDS TO NEAR 30 KTS WL ALSO IMPACT THIS MORE
EXPOSED LOCATION. THE AREA OF PCPN WL EXIT IWD SOON AFTER TAF
ISSUANCE...SO EXPECT AN IMPROVEMENT THERE FM IFR TO MVFR WITH THE
ARRIVAL OF SOME DRIER AIR/SUBSIDENCE. SINCE THE BAND OF HEAVIER PCPN
IS LIKELY TO REMAIN TO THE W OF SAW...THERE SHOULD BE MVFR CIGS WITH
ONLY SOME OCNL -SHRA IN THE PRESENCE OF A DOWNSLOPE WIND COMPONENT.
FOR THIS EVNG...MVFR CONDITIONS SHOULD BE THE RULE WITH MVFR CIGS
AND ONLY SOME SCT LIGHT -SHSN OR -SHSNRA. BUT THE APRCH OF ANOTHER
DISTURBANCE/LO PRES TROF LATE TNGT SHOULD RESULT IN DETERIORATING
CONDITIONS AGAIN WITH IFR CONDITIONS DVLPG AT IWD AND CMX. DOWNSLOPE
WINDS AT SAW WL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO IWD AND CMX BY LATE MRNG ON TUE.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT MON APR 20 2015

AS A LOW LIFTS THROUGH THE SOO THIS AFTERNOON...WINDS WILL BACK TO
THE WEST-NORTHWEST THIS AFTERNOON. WITH THE LOW BECOMING STATIONARY
JUST TO THE SOUTHWEST OF JAMES BAY TONIGHT THROUGH
WEDNESDAY...PERSISTENT NORTHWESTERLY WINDS OF 20-30KTS ARE EXPECTED.
ALTHOUGH THE LOW WILL WEAKEN AND MOVE EAST ACROSS QUEBEC WEDNESDAY
NIGHT INTO THURSDAY...THE NORTHWEST WINDS UP TO 25KTS WILL PERSIST
AS A RIDGE MOVES INTO THE NORTHERN PLAINS. THE WINDS DIMINISH THEN
BELOW 20 KNOTS BY THURSDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...KF
AVIATION...KC
MARINE...07




000
FXUS63 KMQT 201736
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
136 PM EDT MON APR 20 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT MON APR 20 2015

UPPER AIR PATTERN CONSISTS OF A ELONGATED 500 MB TROUGH WITH SEVERAL
SHORTWAVES EMBEDDED IN IT. THE SHORTWAVE OVER LOWER MICHIGAN WILL BE
SPREADING PCPN UP INTO THE CWA THIS MORNING WHILE ANOTHER SHORTWAVE
OVER THE RED RIVER VALLEY OF THE NORTH WILL PUT PCPN IN OVER THE FAR
WEST THIS MORNING. BOTH THESE SHORTWAVES WILL COMBINE OVER THE AREA
AND CAUSE SOME WIDESPREAD PCPN THIS MORNING OVER THE CWA. UPPER
TROUGH SLOWLY MOVES EAST WITH A 500 MB LOW MOVING OVER THE U.P. LATE
TONIGHT. NAM SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE OVER THE CWA THIS MORNING. THE DEEPER MOISTURE REMAIN
OVER THE AREA THROUGH TONIGHT WHILE THE Q-VECTOR CONVERGENCE WEAKENS
AND MOVES OUT BY THIS EVENING BEFORE MOVING BACK IN LATE TONIGHT
WITH THE 500 MB LOW. GFS AND ECMWF SHOW ABOUT THE SAME THING AS
WELL.

HAD TO HANG ONTO THE DRIER AIR ACROSS THE CENTRAL CWA A BIT LONGER
THIS MORNING AND CUT THE QPF AMOUNTS BECAUSE OF THIS. DID GO WITH A
COMBO OF WET BULB HEIGHTS AND WARM TEMPERATURES ALOFT TO DETERMINE
SNOW FOR THIS FORECAST AND LOOKS LIKE THE ACCUMULATING SNOW WILL BE
TONIGHT WHERE UP TO 2 INCHES COULD FALL ACROSS THE WESTERN
HIGHLANDS. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
TEMPERATURE FORECAST AND WENT WITH CATEGORICAL POPS FOR TODAY FOR
THE CWA AND THEN LIKELY POPS IN NORTHWEST LAKE EFFECT BELTS TONIGHT
AND KEPT SOME SLIGHT CHANCE POPS IN THE FAR SOUTH DUE TO THE UPPER
LOW MOVING INTO THE AREA AND WRAPAROUND PCPN IN THE AREA.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 507 AM EDT MON APR 20 2015

COLDER...WITH LITTLE BREAK IN IN THE NEAR FUTURE. THE BEST CHANCE OF
LIGHT PRECIP WILL BE ALONG THE LAKE SUPERIOR SHORELINE.

AT 12Z TUESDAY THE SFC LOW WILL HAVE SHIFTED TO JUST W OF JAMES
BAY...WITH A TROUGH/SECONDARY COLD FRONT EXTENDING OVER CENTRAL LAKE
SUPERIOR AND CENTRAL UPPER MI. 850MB TEMPS AHEAD OF THE TROUGH WILL
AVERAGE AROUND -4C...AND FALL TO AROUND -7C BY THE END OF THE DAY
BEHIND THE TROUGH. THIS WILL COINCIDE WITH THE PASSAGE OF THE LARGE
500MB LOW...CENTERED OVER THE CWA TUESDAY. THE SIZABLE TROUGH WILL
ENCOMPASS E MT THROUGH THE GULF STATES...AND BACK UP THROUGH THE NEW
ENGLAND STATES.

THE 500MB LOW WILL NOT MOVE MUCH...ONLY TO E ONTARIO BY THURSDAY
MORNING. THIS WILL BE SIMILAR TO THE SFC LOW WHICH WILL ONLY SHIFT
TO FAR W ONTARIO DURING THE SAME TIME. LOOK FOR PERSISTENT NW WINDS
AND 850MB TEMPS OF -8 TO -12C.

THE 500MB LOW WILL CONTINUE ITS E PROGRESSION THURSDAY NIGHT THROUGH
FRIDAY...MOVING ACROSS S QUEBEC. WHILE A WEAK RIDGE WILL ATTEMPT TO
BUILD OVER FAR W LAKE SUPERIOR/UPPER MI...THE TROUGH WILL STILL
REMAIN OVER THE E. WHILE THE SFC LOW INITIALLY SHIFTS TO SE QUEBEC
EARLY THURSDAY EVENING...IT LOOKS TO SHIFT BACK W DURING THE DAY
FRIDAY /PARTICULARLY OFF THE GFS SOLUTION/.

THERE LOOKS TO BE SOME DISCREPANCIES IN THE HANDLING OF THE 500MB
LOW FOR THE LATTER HALF OF THE WEEKEND BY THE 00Z MODEL RUNS. WHILE
THE ECMWF PUSHES A RIDGE OVER THE UPPER GREAT LAKES SATURDAY AND
SUNDAY...THE GFS KEEPS THE TROUGH IN PLACE. AS A RESULT...FEW
CHANGES WERE MADE TO THE ONGOING FCST FOR THE WEEKEND. TEMPS MAY
RISE AROUND 5F SUNDAY COMPARED TO SATURDAY...BUT WAS LACKING
CONFIDENCE TO DO MUCH MORE THAN THAT. THE ECMWF SOLUTION WOULD BRING
850MB TEMPS BACK TO -2C BY SATURDAY AFTERNOON WITH THAT RIDGE
BUILDING IN. HOWEVER...THE GFS IS STILL AROUND -8C.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 131 PM EDT MON APR 20 2015

AREA OF DEEPER MSTR ASSOCIATED WITH BAND OF SHARPER FORCING WL BRING
A PERIOD OF STEADY SN TO CMX THRU THIS AFTN ALONG WITH LIFR
CONDITIONS. GUSTY W WINDS TO NEAR 30 KTS WL ALSO IMPACT THIS MORE
EXPOSED LOCATION. THE AREA OF PCPN WL EXIT IWD SOON AFTER TAF
ISSUANCE...SO EXPECT AN IMPROVEMENT THERE FM IFR TO MVFR WITH THE
ARRIVAL OF SOME DRIER AIR/SUBSIDENCE. SINCE THE BAND OF HEAVIER PCPN
IS LIKELY TO REMAIN TO THE W OF SAW...THERE SHOULD BE MVFR CIGS WITH
ONLY SOME OCNL -SHRA IN THE PRESENCE OF A DOWNSLOPE WIND COMPONENT.
FOR THIS EVNG...MVFR CONDITIONS SHOULD BE THE RULE WITH MVFR CIGS
AND ONLY SOME SCT LIGHT -SHSN OR -SHSNRA. BUT THE APRCH OF ANOTHER
DISTURBANCE/LO PRES TROF LATE TNGT SHOULD RESULT IN DETERIORATING
CONDITIONS AGAIN WITH IFR CONDITIONS DVLPG AT IWD AND CMX. DOWNSLOPE
WINDS AT SAW WL RESTRICT THE IMPACT THERE...SO MVFR CIGS SHOULD
PREVAIL. AFTER THIS DISTURBANCE EXITS TO THE E...EXPECT MVFR
CONDITIONS TO RETURN TO IWD AND CMX BY LATE MRNG ON TUE.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT MON APR 20 2015

AS A LOW LIFTS THROUGH THE SOO THIS AFTERNOON...WINDS WILL BACK TO
THE WEST-NORTHWEST THIS AFTERNOON. WITH THE LOW BECOMING STATIONARY
JUST TO THE SOUTHWEST OF JAMES BAY TONIGHT THROUGH
WEDNESDAY...PERSISTENT NORTHWESTERLY WINDS OF 20-30KTS ARE EXPECTED.
ALTHOUGH THE LOW WILL WEAKEN AND MOVE EAST ACROSS QUEBEC WEDNESDAY
NIGHT INTO THURSDAY...THE NORTHWEST WINDS UP TO 25KTS WILL PERSIST
AS A RIDGE MOVES INTO THE NORTHERN PLAINS. THE WINDS DIMINISH THEN
BELOW 20 KNOTS BY THURSDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...KF
AVIATION...KC
MARINE...07



000
FXUS63 KDTX 201718
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
118 PM EDT MON APR 20 2015

.AVIATION...

DISORGANIZED SHOWERS WORKING THROUGH SOUTHEAST MICHIGAN THIS
AFTERNOON AHEAD OF A COLD FRONT... WITH STILL LOW CHANCE OF ISOLATED
THUNDERSTORM DEVELOPING. WINDS WILL BE GUSTING BETWEEN 30 TO 40
KNOTS WITHIN ANY OF THE STRONGER SHOWERS. MVFR/LOW VFR CEILINGS
WILL HOLD INTO THE EARLY EVENING HOURS...AND STILL COULD BE
ISOLATED-SCATTERED LIGHT RAIN SHOWERS LEFT OVER...BUT WINDS
SHIFTING A BIT MORE SOUTHWEST-WEST BEHIND THE COLD FRONT WILL
ALLOW FOR A DRYING TREND. CLOUD COVER TONIGHT IS SOMEWHAT
UNCERTAIN AS COLD CYCLONIC FLOW OFF LAKE MICHIGAN MAY BE
SUFFICIENT TO MAINTAIN THE LOW VFR/BORDERLINE MVFR CEILINGS. IF
SKIES DO SCATTER OUT TONIGHT...HIGHER CONFIDENCE IN LOW VFR
CEILINGS REDEVELOPING TOMORROW MORNING...WITH POSSIBLY ENOUGH
INSTABILITY TO GENERATE SCATTERED SHOWERS DURING THE DAY. IT WILL
BE WINDY...ESPECIALLY UNDERNEATH ANY SHOWERS...AS WINDS COULD GUST
IN EXCESS OF 35 KNOTS.

FOR DTW...SHOWERS WILL BE CLEARING THE TERMINAL AT THE START OF THE
TAF PERIOD. THERE IS A CHANCE OF A COUPLE LIGHT RAIN SHOWERS EARLY
THIS EVENING...BUT AREA COVERAGE PRECLUDED THE MENTION.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CIGS AOB 5KFT THROUGH EARLY EARLY EVENING...THEN
  MEDIUM CONFIDENCE.

&&

.PREV DISCUSSION...ISSUED 353 AM EDT MON APR 20 2015

SHORT TERM...TODAY AND TONIGHT

THE WELL ADVERTISED STRONG LOW PRESSURE SYSTEM HAS LIFTED INTO SW
LOWER MI AS OF 07Z THIS MORNING. IT WILL CONTINUE NORTHWARD REACHING
ONTARIO BY 00Z THIS EVENING. ALTHOUGH THE MAIN WING OF ISENTROPIC
ASCENT NORTH OF THE WARM FRONT AND COLOCATED RIBBON OF ENHANCED
MOISTURE IS NORTH OF SE MI...ELEVATED MOISTURE VALUES WILL LINGER
INTO THE EARLY AFTERNOON AS IT APPEARS THE EASTERN PORTION OF THE
CWA SHOULD RESIDE IN THE WARM SECTOR FOR SEVERAL HOURS. HOW THE
AFTERNOON WILL SHAPE UP WILL DEPEND ON A COMPACT SHORTWAVE ROTATING
AROUND THE BASE THE MID LEVEL TROUGH WHICH IS OVER THE UPPER
MISSISSIPPI VALLEY AND WILL SWING THROUGH THE OHIO VALLEY LATER
TODAY. THIS SHORTWAVE IS FORECAST TO LIFT SOMEWHERE THROUGH SE LOWER
MI OR WESTERN LAKE ERIE. THIS HAS BIG IMPLICATIONS ON THE FORECAST
DUE TO THE TIMING OF THE COLD FRONT THIS SECONDARY LOW WILL PULL
THROUGH THE AREA. CURRENTLY MODELS HAVE THE TIMING FAIRLY WELL
PEGGED DOWN TO THE 18-21Z TIMEFRAME. THIS WOULD ALLOW ENOUGH DIURNAL
HEATING TO POTENTIALLY BUILD UP A FEW HUNDRED J/KG OF CAPE AHEAD OF
THE APPROACHING COLD FRONT WITH VERY FAVORABLE LL LAPSE RATES AND
DEEP LAYER OF STRONG SW FLOW WITH SPEED SHEAR SETTING UP IN THE WARM
SECTOR. SPC HAS EXPANDED THE MARGINAL AREA TO INCLUDE A SLIVER OF
EXTREME EASTERN LOWER MI...EAST OF A LINE FROM ABOUT ADRIAN TO PORT
HURON. THERE IS CONCERN AS TO WHETHER THIS WILL ACTUALLY CONCERN AS
THE NAM/GEMREG/HRRR/ETC... SUGGEST THAT THE LL JET MAX WILL DRIFT
EASTWARD AND IGNITE THE COLD FRONT JUST SE OF MI LEAVING US WITH
ONLY RESIDUAL SHOWERS AND ISOLATED RUMBLES OF THUNDER AS THE FRONTAL
BOUNDARIES OCCLUDE AND SLIDE THROUGH THE AREA WITH THE TRIPLE POINT
STAYING SOUTH. AFTER SEVERAL MODEL RUNS TRENDING WESTWARD...THE
RECENT RUNS ARE STALLING IF NOT SHIFTING SLIGHTLY FURTHER EAST WHICH
LENDS CREDENCE THUNDERSTORM POTENTIAL DOUBTS. OVERALL THINK WE WILL
GET BRUSHED WITH SOME THUNDERSTORMS BUT THE BETTER ORGANIZED STORMS
WILL LIKELY STAY OUT OF THE AREA.

IN ADDITION TO COLD FRONTAL THUNDERSTORM POTENTIAL...WINDS WILL BE
QUITE GUSTY THROUGH THE DAY. THE DEEP MIXED LAYER WITH 900MB WINDS
MAKING A RUN AT 40 KNOTS WILL KEEP SW SFC FLOW AROUND 20KT WITH
GUSTS APPROACHING 35 KNOTS...ESPECIALLY EARLY THIS AFTERNOON EAST OF
THE FRONT.

AS THE FOR THE REST OF THE EVENING AND INTO THE OVERNIGHT...THE COLD
FRONT...OR OCCLUDED FRONT...WILL USHER IN MUCH COOLER AIR WHILE
KEEPING THE MIXED LAYER IN TACK THROUGH THE NIGHT WHICH WILL IN TURN
KEEP WINDS ELEVATED. THE ENHANCED MOISTURE PLUME WILL BE SHUNTED
EAST BUT SCATTERED SHOWERS WILL LINGER THROUGH THE OVERNIGHT AS CAA
RESULTS IN MORE FAVORABLE MID LEVEL LAPSE RATES. THE MIXING AND
CLOUD COVER WILL KEEP MIN TEMPS UP AROUND 40 FOR MOST LOCATIONS.

LONG TERM...

CLOSED UPPER LOW WILL REMAIN PARKED OVERHEAD THROUGH MIDWEEK.
EMBEDDED SHORTWAVES WILL BRING EPISODIC SHOWER ACTIVITY, THE TIMING
OF WHICH WILL REMAIN INHERENTLY ILL-DEFINED OUTSIDE OF 48 HOURS. A
COLD COLUMN AND CLOUD COVER WILL KEEP TEMPERATURES SOLIDLY BELOW
NORMAL.

LOW CENTER WILL MEANDER FROM INTERNATIONAL FALLS THIS AFTN TO THE
STRAITS BY MIDDAY TUESDAY. APRIL INSOLATION AND VERY COLD H5 TEMPS
WITHIN THE MID-LEVEL COLD POOL OF -30C WILL RESULT IN A DEEP MIXED
LAYER PERHAPS APPROACHING 600MB. ROBUST WSW WIND FIELD WITHIN THIS
VERY WELL-MIXED ENVIRONMENT WILL SET THE STAGE FOR WIDESPREAD WIND
GUSTS IN EXCESS OF 30 KNOTS FOR THE BALANCE OF TUESDAY AFTERNOON.
THE TRADE-OFF OF THE DEEP MIXING WILL BE TEMPERATURES REACHING THE
LOW 50S IN SPITE OF SUB-ZERO 850MB TEMPERATURES. SUFFICIENT MID-
LEVEL MOISTURE RESIDING IN THE 800-600MB LAYER WILL RESULT IN, AT
MINIMUM, WIDESPREAD AFTERNOON CLOUDS. MODELS ALSO POINT TO MID-
MORNING SHOWER GENERATION AS WELL, GIVEN A FEW HUNDRED J/KG CAPE
AVAILABLE FOR SURFACE BASED PARCELS. PASSING ELONGATED H4 PV ANOMALY
WILL PROVIDE BROAD SCALE ASCENT WHILE INLAND TROUGHING HELPS IS
NOTED TO HELP FOCUS ACTIVITY ALONG/NORTH OF M59. CLASSIC INVERTED V
THERMODYNAMIC PROFILE WILL ALLOW SHOWERS TO POTENTIALLY PRODUCE WIND
GUSTS OF 45 KTS.

LOSS OF DIURNAL HEATING WILL MEAN AN END TO SHOWERS TUESDAY EVENING.
THE GRADIENT WILL REMAIN ELEVATED AS BROAD LOW PRESSURE REMAINS
CENTERED OVER THE GREAT LAKES. COMBINED WITH CLOUDS, LOW
TEMPERATURES WILL BE COLD - BUT NOT AS COLD AS THEY COULD BE GIVEN
THE AIRMASS. PREFER NAM12 DEPICTION OF 34-38F TUESDAY NIGHT.

LITTLE CHANGE IN SYNOPTIC SCALE REGIME FOR WEDNESDAY, MEANING
CONTINUED DIURNALLY DRIVEN BOUNDARY LAYER CLOUD COVER AND AFTERNOON
WIND GUSTS IN THE 25-30 KT RANGE FROM THE WEST. BETTER LOW-LEVEL
MOISTURE QUALITY WILL BE OFFSET BY LACK OF FOCUSED FORCING, BUT HAVE
TO RESPECT POTENTIAL WITH A LOW END CHC POP. THE MOST NOTEWORTHY
CHANGE BY WED WILL BE POSITION OF THE THERMAL TROUGH OVERHEAD AS H85
TEMPERATURES FALL TO -6 TO -7C SUPPORTING HIGHS IN THE MID 40S AND
WIND CHILLS IN THE MID 30S.

MARINE...

FRESH TO LOCALLY STRONG SOUTHEAST WINDS WILL VEER TO THE SOUTHWEST
THROUGH TODAY. A FEW GUSTS TO NEAR GALES WILL BE POSSIBLE...MAINLY
IN NEARSHORE ZONES INCLUDING LAKE SAINT CLAIR AND ERIE. SMALL CRAFT
ADVISORIES THEREFORE REMAIN IN EFFECT FOR ALL NEARSHORE ZONES.
BREEZY WESTERLY WINDS WILL PERSIST THROUGH MIDWEEK AS CONDITIONS
REMAIN RELATIVELY STATIC WITH LOW PRESSURE PARKED OVER THE GREAT
LAKES. ADDITIONAL SMALL CRAFT ADVISORIES FOR WIND WILL LIKELY BE
NEEDED ON TUESDAY AND POSSIBLY ONCE MORE ON WEDNESDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LHZ421-422-
     441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LEZ444.

&&

$$

AVIATION.....SF
SHORT TERM...DRK
LONG TERM....JVC
MARINE.......JVC


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).




000
FXUS63 KGRR 201619
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1220 PM EDT MON APR 20 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EDT MON APR 20 2015

A CHILLY WEEK IS DEVELOPING AS LOW PRESSURE HAS MOVED OVER THE GREAT
LAKES. COOLER AIR WILL FLOW INTO WEST MICHIGAN BEHIND THE LOW. RAIN
SHOWERS MAY MIX WITH WET SNOW AT TIMES. MINOR ACCUMULATIONS ARE
POSSIBLE TUESDAY NIGHT NEAR US 10. HIGHS WILL BE IN THE MID 40S TO
MID 50S THROUGH THE END OF THE WEEK.

&&

.UPDATE...
ISSUED AT 1152 AM EDT MON APR 20 2015

OVERALL THE ONGOING FORECAST LOOKS FINE. I DID SOME MINOR
ADJUSTMENTS TO THE POPS BASED ON RECENT RADAR TRENDS AND
CONSIDERING THERE IS ANOTHER SHORTWAVE THAT MOVES INTO THE AREA
THIS EVENING TO HELP INCREASE THE SHOWER ACTIVITY. IT WILL BE
BREEZY TODAY THROUGH TUESDAY BUT I DO NOT BELIEVE IT WILL BE WINDY
ENOUGH FOR A WIND ADVISORY.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

FORECAST CONCERNS CONTINUE TO DEAL WITH THE EVOLUTION OF THE LOW
MOVING ACROSS LOWER MICHIGAN. OVERALL...THE FORECAST IS UNFOLDING AS
EXPECTED.

LOCAL AND REGIONAL RADAR SHOWS RAIN SHOWERS MOVING NORTH ACROSS THE
CWA. OVERALL COVERAGE THOUGH IS BEGINNING TO DECREASE SOUTH OF THE
MI/IN BORDER AS THE LOW MOVES NORTH. SREF SHOWS THAT PCPN WILL FILL
BACK IN ACROSS THE SOUTHERN CWA LATER THIS MORNING AS A SHORT WAVE
ALOFT PIVOTS TOWARD LOWER MICHIGAN BEFORE DIMINISHING AGAIN LATER
THIS AFTERNOON. AT THIS POINT THE HEAVIEST AND STEADIEST RAIN
APPEARS TO BE WINDING DOWN. WHAT WE/LL BE LEFT WITH IS SCATTERED TO
NUMEROUS SHOWERS TODAY AND A BIT LESS TONIGHT.

TUESDAY THE CORE OF THE UPPER LOW MOVES OVERHEAD. LOOK FOR PCPN TO
INCREASE IN COVERAGE AGAIN AS INSTABILITY ALOFT INCREASES A BIT DUE
STEEPENING LAPSE RATES COURTESY OF H5 TEMPS NEAR -30C MOVING OVER
THE CWA. THE COLDER AIR WILL REMAIN WITH US THROUGH TUESDAY NIGHT.
THAT/S WHEN WE COULD SEE SOME WET SNOW MIX IN WITH THE RAIN SHOWERS.
MINOR...LESS THAN AN INCH...ACCUMS SEEM POSSIBLE IN OSCEOLA/CLARE
COUNTIES TUESDAY NIGHT. THE UPPER LOW WILL BE VERY SLOW TO MOVE OUT
AND WE/LL SEE THE COOL SHOWERY PCPN CONTINUE WEDNESDAY AS A COUPLE
OF SHORT WAVES ROTATE AROUND THE UPPER LOW AND ACROSS LOWER MICHIGAN.

HIGHS WILL BE BELOW NORMAL THROUGH THE SHORT TERM RANGING FROM THE
MID 40S TO MID 50S.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

THE COLD UPPER LOW REMAINS OVERHEAD THROUGH THURSDAY THEN MOVES INTO
NEW ENGLAND/SRN QUEBEC FOR THE WEEKEND. A SLIGHT CHANCE OF LIGHT
RAIN AND SNOW SHOWERS WILL LINGER THROUGH ABOUT THURSDAY NIGHT WHILE
H8 TEMPS AROUND -7C AND CYCLONIC FLOW ARE STILL PRESENT... OTHERWISE
DRY BUT CHILLY WEATHER IS EXPECTED WITH SFC HIGH PRESSURE MOVING IN.

THIS WEEKEND WE WILL STILL BE ON THE WRN PERIPHERY OF THE BROAD NEW
ENGLAND UPPER LOW. THE CONFLUENT/SHEARING UPPER LEVEL FLOW OVERHEAD
ASSOCIATED WITH THIS FEATURE HELPS TO FEND OFF RAIN ASSOCIATED WITH
A SYSTEM MOVING EAST FROM THE CENTRAL PLAINS. GUIDANCE SHOWS QPF
REMAINING TO OUR SOUTH WITH WEAK SURFACE RIDGING PREVAILING OVER THE
WEEKEND. TEMPERATURES WILL RECOVER A BIT AND HIGHS IN THE 50S ARE
EXPECTED SATURDAY AND SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY)
ISSUED AT 1220 PM EDT MON APR 20 2015

MAINLY IFR/MVFR CONDITIONS WILL CONTINUE THROUGH MID TO LATE
AFTERNOON DUE TO LOW CIGS AND SCATTERED SHOWERS AND PATCHY FOG
BEFORE GRADUALLY IMPROVING TO VFR THIS EVENING AND OVERNIGHT.

IT WILL BE BREEZY THIS AFTERNOON WITH SW WINDS OF 15 TO 25 KTS WITH
GUSTS TO AROUND 30 KTS. SOUTHWEST TO WEST WINDS WILL STAY UP AROUND
15 TO 25 KTS OVERNIGHT AND THEN VEER TO THE WEST AND INCREASE TO 20
TO 25 KTS WITH GUSTS TO AROUND 30 KTS BY MID TO LATE TUESDAY MORNING.

SCATTERED LIGHT RAIN SHOWERS WILL LINGER OVERNIGHT AND THEN BECOME
MORE PREVALENT ON TUESDAY. MAINLY VFR CONDITIONS ARE ANTICIPATED
TUESDAY ALTHOUGH SOME PATCHY MVFR IS POSSIBLE DUE TO LOWER CIGS AND
HEAVIER SHOWERS.

&&

.MARINE...
ISSUED AT 752 AM EDT MON APR 20 2015

ADDED AREAS OF DENSE FOG TO THE NEARSHORE FORECAST TODAY. DESPITE
GOOD MIXING... DEW POINTS IN THE 40S OVER THE COLD LAKE WATERS IS
PRODUCING FOG PER POST SUNRISE WEB CAMS AT MKG/HOLLAND.

LEFT THE SMALL CRAFT ADVISORY AS IS SOUTH OF WHITEHALL. AS THE LOW
MOVES FARTHER AWAY...WINDS WILL INCREASE FROM THE SOUTHWEST AND
WAVES WILL ALSO RESPOND. A SMALL CRAFT ADVISORY MAY ALSO BE NEEDED
NORTH OF WHITEHALL TONIGHT.

&&

.HYDROLOGY...
ISSUED AT 1156 AM EDT MON APR 20 2015

WIDESPREAD RAINFALL THROUGH 8 AM THIS MORNING PRODUCED 0.50 TO 0.75
INCHES ACROSS MOST OF THE GRAND AND MUSKEGON RIVER BASINS. FURTHER
SOUTH ACROSS THE KALAMAZOO RIVER BASIN...RAINFALL AMOUNTS WERE
HIGHER IN THE 0.75 TO 1.00 INCH RANGE. AS EXPECTED...GRADUAL RIVER
RISES HAVE BEGUN ON MOST AREA RIVERS. GENERAL HYDRO THINKING HAS NOT
CHANGED MUCH...MOSTLY WITHIN BANK RISES ARE EXPECTED. A FEW SITES
COULD EXCEED BANKFULL. BUT WITH RAIN TODAY AND TONIGHT BEING OF THE
SCATTERED AND LIGHT VARIETY...SIGNIFICANT FLOODING IS NOT EXPECTED.

FORECAST RAINFALL TODAY AND TONIGHT IS IN THE 0.10 TO 0.25 INCH
RANGE. EVEN LIGHTER PRECIP AMOUNTS ARE EXPECTED TUESDAY
INTO WEDNESDAY. A SLIGHT CHANCE OF LIGHT RAIN AND SNOW WILL LINGER
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. BUT MAINLY DRY AND CHILLY
WEATHER IS EXPECTED TOWARD THE END OF THE WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

UPDATE...WDM
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...LAURENS
HYDROLOGY...EBW
MARINE...04







000
FXUS63 KGRR 201619
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1220 PM EDT MON APR 20 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EDT MON APR 20 2015

A CHILLY WEEK IS DEVELOPING AS LOW PRESSURE HAS MOVED OVER THE GREAT
LAKES. COOLER AIR WILL FLOW INTO WEST MICHIGAN BEHIND THE LOW. RAIN
SHOWERS MAY MIX WITH WET SNOW AT TIMES. MINOR ACCUMULATIONS ARE
POSSIBLE TUESDAY NIGHT NEAR US 10. HIGHS WILL BE IN THE MID 40S TO
MID 50S THROUGH THE END OF THE WEEK.

&&

.UPDATE...
ISSUED AT 1152 AM EDT MON APR 20 2015

OVERALL THE ONGOING FORECAST LOOKS FINE. I DID SOME MINOR
ADJUSTMENTS TO THE POPS BASED ON RECENT RADAR TRENDS AND
CONSIDERING THERE IS ANOTHER SHORTWAVE THAT MOVES INTO THE AREA
THIS EVENING TO HELP INCREASE THE SHOWER ACTIVITY. IT WILL BE
BREEZY TODAY THROUGH TUESDAY BUT I DO NOT BELIEVE IT WILL BE WINDY
ENOUGH FOR A WIND ADVISORY.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

FORECAST CONCERNS CONTINUE TO DEAL WITH THE EVOLUTION OF THE LOW
MOVING ACROSS LOWER MICHIGAN. OVERALL...THE FORECAST IS UNFOLDING AS
EXPECTED.

LOCAL AND REGIONAL RADAR SHOWS RAIN SHOWERS MOVING NORTH ACROSS THE
CWA. OVERALL COVERAGE THOUGH IS BEGINNING TO DECREASE SOUTH OF THE
MI/IN BORDER AS THE LOW MOVES NORTH. SREF SHOWS THAT PCPN WILL FILL
BACK IN ACROSS THE SOUTHERN CWA LATER THIS MORNING AS A SHORT WAVE
ALOFT PIVOTS TOWARD LOWER MICHIGAN BEFORE DIMINISHING AGAIN LATER
THIS AFTERNOON. AT THIS POINT THE HEAVIEST AND STEADIEST RAIN
APPEARS TO BE WINDING DOWN. WHAT WE/LL BE LEFT WITH IS SCATTERED TO
NUMEROUS SHOWERS TODAY AND A BIT LESS TONIGHT.

TUESDAY THE CORE OF THE UPPER LOW MOVES OVERHEAD. LOOK FOR PCPN TO
INCREASE IN COVERAGE AGAIN AS INSTABILITY ALOFT INCREASES A BIT DUE
STEEPENING LAPSE RATES COURTESY OF H5 TEMPS NEAR -30C MOVING OVER
THE CWA. THE COLDER AIR WILL REMAIN WITH US THROUGH TUESDAY NIGHT.
THAT/S WHEN WE COULD SEE SOME WET SNOW MIX IN WITH THE RAIN SHOWERS.
MINOR...LESS THAN AN INCH...ACCUMS SEEM POSSIBLE IN OSCEOLA/CLARE
COUNTIES TUESDAY NIGHT. THE UPPER LOW WILL BE VERY SLOW TO MOVE OUT
AND WE/LL SEE THE COOL SHOWERY PCPN CONTINUE WEDNESDAY AS A COUPLE
OF SHORT WAVES ROTATE AROUND THE UPPER LOW AND ACROSS LOWER MICHIGAN.

HIGHS WILL BE BELOW NORMAL THROUGH THE SHORT TERM RANGING FROM THE
MID 40S TO MID 50S.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

THE COLD UPPER LOW REMAINS OVERHEAD THROUGH THURSDAY THEN MOVES INTO
NEW ENGLAND/SRN QUEBEC FOR THE WEEKEND. A SLIGHT CHANCE OF LIGHT
RAIN AND SNOW SHOWERS WILL LINGER THROUGH ABOUT THURSDAY NIGHT WHILE
H8 TEMPS AROUND -7C AND CYCLONIC FLOW ARE STILL PRESENT... OTHERWISE
DRY BUT CHILLY WEATHER IS EXPECTED WITH SFC HIGH PRESSURE MOVING IN.

THIS WEEKEND WE WILL STILL BE ON THE WRN PERIPHERY OF THE BROAD NEW
ENGLAND UPPER LOW. THE CONFLUENT/SHEARING UPPER LEVEL FLOW OVERHEAD
ASSOCIATED WITH THIS FEATURE HELPS TO FEND OFF RAIN ASSOCIATED WITH
A SYSTEM MOVING EAST FROM THE CENTRAL PLAINS. GUIDANCE SHOWS QPF
REMAINING TO OUR SOUTH WITH WEAK SURFACE RIDGING PREVAILING OVER THE
WEEKEND. TEMPERATURES WILL RECOVER A BIT AND HIGHS IN THE 50S ARE
EXPECTED SATURDAY AND SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY)
ISSUED AT 1220 PM EDT MON APR 20 2015

MAINLY IFR/MVFR CONDITIONS WILL CONTINUE THROUGH MID TO LATE
AFTERNOON DUE TO LOW CIGS AND SCATTERED SHOWERS AND PATCHY FOG
BEFORE GRADUALLY IMPROVING TO VFR THIS EVENING AND OVERNIGHT.

IT WILL BE BREEZY THIS AFTERNOON WITH SW WINDS OF 15 TO 25 KTS WITH
GUSTS TO AROUND 30 KTS. SOUTHWEST TO WEST WINDS WILL STAY UP AROUND
15 TO 25 KTS OVERNIGHT AND THEN VEER TO THE WEST AND INCREASE TO 20
TO 25 KTS WITH GUSTS TO AROUND 30 KTS BY MID TO LATE TUESDAY MORNING.

SCATTERED LIGHT RAIN SHOWERS WILL LINGER OVERNIGHT AND THEN BECOME
MORE PREVALENT ON TUESDAY. MAINLY VFR CONDITIONS ARE ANTICIPATED
TUESDAY ALTHOUGH SOME PATCHY MVFR IS POSSIBLE DUE TO LOWER CIGS AND
HEAVIER SHOWERS.

&&

.MARINE...
ISSUED AT 752 AM EDT MON APR 20 2015

ADDED AREAS OF DENSE FOG TO THE NEARSHORE FORECAST TODAY. DESPITE
GOOD MIXING... DEW POINTS IN THE 40S OVER THE COLD LAKE WATERS IS
PRODUCING FOG PER POST SUNRISE WEB CAMS AT MKG/HOLLAND.

LEFT THE SMALL CRAFT ADVISORY AS IS SOUTH OF WHITEHALL. AS THE LOW
MOVES FARTHER AWAY...WINDS WILL INCREASE FROM THE SOUTHWEST AND
WAVES WILL ALSO RESPOND. A SMALL CRAFT ADVISORY MAY ALSO BE NEEDED
NORTH OF WHITEHALL TONIGHT.

&&

.HYDROLOGY...
ISSUED AT 1156 AM EDT MON APR 20 2015

WIDESPREAD RAINFALL THROUGH 8 AM THIS MORNING PRODUCED 0.50 TO 0.75
INCHES ACROSS MOST OF THE GRAND AND MUSKEGON RIVER BASINS. FURTHER
SOUTH ACROSS THE KALAMAZOO RIVER BASIN...RAINFALL AMOUNTS WERE
HIGHER IN THE 0.75 TO 1.00 INCH RANGE. AS EXPECTED...GRADUAL RIVER
RISES HAVE BEGUN ON MOST AREA RIVERS. GENERAL HYDRO THINKING HAS NOT
CHANGED MUCH...MOSTLY WITHIN BANK RISES ARE EXPECTED. A FEW SITES
COULD EXCEED BANKFULL. BUT WITH RAIN TODAY AND TONIGHT BEING OF THE
SCATTERED AND LIGHT VARIETY...SIGNIFICANT FLOODING IS NOT EXPECTED.

FORECAST RAINFALL TODAY AND TONIGHT IS IN THE 0.10 TO 0.25 INCH
RANGE. EVEN LIGHTER PRECIP AMOUNTS ARE EXPECTED TUESDAY
INTO WEDNESDAY. A SLIGHT CHANCE OF LIGHT RAIN AND SNOW WILL LINGER
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. BUT MAINLY DRY AND CHILLY
WEATHER IS EXPECTED TOWARD THE END OF THE WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

UPDATE...WDM
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...LAURENS
HYDROLOGY...EBW
MARINE...04








000
FXUS63 KGRR 201619
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1220 PM EDT MON APR 20 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EDT MON APR 20 2015

A CHILLY WEEK IS DEVELOPING AS LOW PRESSURE HAS MOVED OVER THE GREAT
LAKES. COOLER AIR WILL FLOW INTO WEST MICHIGAN BEHIND THE LOW. RAIN
SHOWERS MAY MIX WITH WET SNOW AT TIMES. MINOR ACCUMULATIONS ARE
POSSIBLE TUESDAY NIGHT NEAR US 10. HIGHS WILL BE IN THE MID 40S TO
MID 50S THROUGH THE END OF THE WEEK.

&&

.UPDATE...
ISSUED AT 1152 AM EDT MON APR 20 2015

OVERALL THE ONGOING FORECAST LOOKS FINE. I DID SOME MINOR
ADJUSTMENTS TO THE POPS BASED ON RECENT RADAR TRENDS AND
CONSIDERING THERE IS ANOTHER SHORTWAVE THAT MOVES INTO THE AREA
THIS EVENING TO HELP INCREASE THE SHOWER ACTIVITY. IT WILL BE
BREEZY TODAY THROUGH TUESDAY BUT I DO NOT BELIEVE IT WILL BE WINDY
ENOUGH FOR A WIND ADVISORY.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

FORECAST CONCERNS CONTINUE TO DEAL WITH THE EVOLUTION OF THE LOW
MOVING ACROSS LOWER MICHIGAN. OVERALL...THE FORECAST IS UNFOLDING AS
EXPECTED.

LOCAL AND REGIONAL RADAR SHOWS RAIN SHOWERS MOVING NORTH ACROSS THE
CWA. OVERALL COVERAGE THOUGH IS BEGINNING TO DECREASE SOUTH OF THE
MI/IN BORDER AS THE LOW MOVES NORTH. SREF SHOWS THAT PCPN WILL FILL
BACK IN ACROSS THE SOUTHERN CWA LATER THIS MORNING AS A SHORT WAVE
ALOFT PIVOTS TOWARD LOWER MICHIGAN BEFORE DIMINISHING AGAIN LATER
THIS AFTERNOON. AT THIS POINT THE HEAVIEST AND STEADIEST RAIN
APPEARS TO BE WINDING DOWN. WHAT WE/LL BE LEFT WITH IS SCATTERED TO
NUMEROUS SHOWERS TODAY AND A BIT LESS TONIGHT.

TUESDAY THE CORE OF THE UPPER LOW MOVES OVERHEAD. LOOK FOR PCPN TO
INCREASE IN COVERAGE AGAIN AS INSTABILITY ALOFT INCREASES A BIT DUE
STEEPENING LAPSE RATES COURTESY OF H5 TEMPS NEAR -30C MOVING OVER
THE CWA. THE COLDER AIR WILL REMAIN WITH US THROUGH TUESDAY NIGHT.
THAT/S WHEN WE COULD SEE SOME WET SNOW MIX IN WITH THE RAIN SHOWERS.
MINOR...LESS THAN AN INCH...ACCUMS SEEM POSSIBLE IN OSCEOLA/CLARE
COUNTIES TUESDAY NIGHT. THE UPPER LOW WILL BE VERY SLOW TO MOVE OUT
AND WE/LL SEE THE COOL SHOWERY PCPN CONTINUE WEDNESDAY AS A COUPLE
OF SHORT WAVES ROTATE AROUND THE UPPER LOW AND ACROSS LOWER MICHIGAN.

HIGHS WILL BE BELOW NORMAL THROUGH THE SHORT TERM RANGING FROM THE
MID 40S TO MID 50S.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

THE COLD UPPER LOW REMAINS OVERHEAD THROUGH THURSDAY THEN MOVES INTO
NEW ENGLAND/SRN QUEBEC FOR THE WEEKEND. A SLIGHT CHANCE OF LIGHT
RAIN AND SNOW SHOWERS WILL LINGER THROUGH ABOUT THURSDAY NIGHT WHILE
H8 TEMPS AROUND -7C AND CYCLONIC FLOW ARE STILL PRESENT... OTHERWISE
DRY BUT CHILLY WEATHER IS EXPECTED WITH SFC HIGH PRESSURE MOVING IN.

THIS WEEKEND WE WILL STILL BE ON THE WRN PERIPHERY OF THE BROAD NEW
ENGLAND UPPER LOW. THE CONFLUENT/SHEARING UPPER LEVEL FLOW OVERHEAD
ASSOCIATED WITH THIS FEATURE HELPS TO FEND OFF RAIN ASSOCIATED WITH
A SYSTEM MOVING EAST FROM THE CENTRAL PLAINS. GUIDANCE SHOWS QPF
REMAINING TO OUR SOUTH WITH WEAK SURFACE RIDGING PREVAILING OVER THE
WEEKEND. TEMPERATURES WILL RECOVER A BIT AND HIGHS IN THE 50S ARE
EXPECTED SATURDAY AND SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY)
ISSUED AT 1220 PM EDT MON APR 20 2015

MAINLY IFR/MVFR CONDITIONS WILL CONTINUE THROUGH MID TO LATE
AFTERNOON DUE TO LOW CIGS AND SCATTERED SHOWERS AND PATCHY FOG
BEFORE GRADUALLY IMPROVING TO VFR THIS EVENING AND OVERNIGHT.

IT WILL BE BREEZY THIS AFTERNOON WITH SW WINDS OF 15 TO 25 KTS WITH
GUSTS TO AROUND 30 KTS. SOUTHWEST TO WEST WINDS WILL STAY UP AROUND
15 TO 25 KTS OVERNIGHT AND THEN VEER TO THE WEST AND INCREASE TO 20
TO 25 KTS WITH GUSTS TO AROUND 30 KTS BY MID TO LATE TUESDAY MORNING.

SCATTERED LIGHT RAIN SHOWERS WILL LINGER OVERNIGHT AND THEN BECOME
MORE PREVALENT ON TUESDAY. MAINLY VFR CONDITIONS ARE ANTICIPATED
TUESDAY ALTHOUGH SOME PATCHY MVFR IS POSSIBLE DUE TO LOWER CIGS AND
HEAVIER SHOWERS.

&&

.MARINE...
ISSUED AT 752 AM EDT MON APR 20 2015

ADDED AREAS OF DENSE FOG TO THE NEARSHORE FORECAST TODAY. DESPITE
GOOD MIXING... DEW POINTS IN THE 40S OVER THE COLD LAKE WATERS IS
PRODUCING FOG PER POST SUNRISE WEB CAMS AT MKG/HOLLAND.

LEFT THE SMALL CRAFT ADVISORY AS IS SOUTH OF WHITEHALL. AS THE LOW
MOVES FARTHER AWAY...WINDS WILL INCREASE FROM THE SOUTHWEST AND
WAVES WILL ALSO RESPOND. A SMALL CRAFT ADVISORY MAY ALSO BE NEEDED
NORTH OF WHITEHALL TONIGHT.

&&

.HYDROLOGY...
ISSUED AT 1156 AM EDT MON APR 20 2015

WIDESPREAD RAINFALL THROUGH 8 AM THIS MORNING PRODUCED 0.50 TO 0.75
INCHES ACROSS MOST OF THE GRAND AND MUSKEGON RIVER BASINS. FURTHER
SOUTH ACROSS THE KALAMAZOO RIVER BASIN...RAINFALL AMOUNTS WERE
HIGHER IN THE 0.75 TO 1.00 INCH RANGE. AS EXPECTED...GRADUAL RIVER
RISES HAVE BEGUN ON MOST AREA RIVERS. GENERAL HYDRO THINKING HAS NOT
CHANGED MUCH...MOSTLY WITHIN BANK RISES ARE EXPECTED. A FEW SITES
COULD EXCEED BANKFULL. BUT WITH RAIN TODAY AND TONIGHT BEING OF THE
SCATTERED AND LIGHT VARIETY...SIGNIFICANT FLOODING IS NOT EXPECTED.

FORECAST RAINFALL TODAY AND TONIGHT IS IN THE 0.10 TO 0.25 INCH
RANGE. EVEN LIGHTER PRECIP AMOUNTS ARE EXPECTED TUESDAY
INTO WEDNESDAY. A SLIGHT CHANCE OF LIGHT RAIN AND SNOW WILL LINGER
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. BUT MAINLY DRY AND CHILLY
WEATHER IS EXPECTED TOWARD THE END OF THE WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

UPDATE...WDM
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...LAURENS
HYDROLOGY...EBW
MARINE...04







000
FXUS63 KGRR 201619
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1220 PM EDT MON APR 20 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EDT MON APR 20 2015

A CHILLY WEEK IS DEVELOPING AS LOW PRESSURE HAS MOVED OVER THE GREAT
LAKES. COOLER AIR WILL FLOW INTO WEST MICHIGAN BEHIND THE LOW. RAIN
SHOWERS MAY MIX WITH WET SNOW AT TIMES. MINOR ACCUMULATIONS ARE
POSSIBLE TUESDAY NIGHT NEAR US 10. HIGHS WILL BE IN THE MID 40S TO
MID 50S THROUGH THE END OF THE WEEK.

&&

.UPDATE...
ISSUED AT 1152 AM EDT MON APR 20 2015

OVERALL THE ONGOING FORECAST LOOKS FINE. I DID SOME MINOR
ADJUSTMENTS TO THE POPS BASED ON RECENT RADAR TRENDS AND
CONSIDERING THERE IS ANOTHER SHORTWAVE THAT MOVES INTO THE AREA
THIS EVENING TO HELP INCREASE THE SHOWER ACTIVITY. IT WILL BE
BREEZY TODAY THROUGH TUESDAY BUT I DO NOT BELIEVE IT WILL BE WINDY
ENOUGH FOR A WIND ADVISORY.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

FORECAST CONCERNS CONTINUE TO DEAL WITH THE EVOLUTION OF THE LOW
MOVING ACROSS LOWER MICHIGAN. OVERALL...THE FORECAST IS UNFOLDING AS
EXPECTED.

LOCAL AND REGIONAL RADAR SHOWS RAIN SHOWERS MOVING NORTH ACROSS THE
CWA. OVERALL COVERAGE THOUGH IS BEGINNING TO DECREASE SOUTH OF THE
MI/IN BORDER AS THE LOW MOVES NORTH. SREF SHOWS THAT PCPN WILL FILL
BACK IN ACROSS THE SOUTHERN CWA LATER THIS MORNING AS A SHORT WAVE
ALOFT PIVOTS TOWARD LOWER MICHIGAN BEFORE DIMINISHING AGAIN LATER
THIS AFTERNOON. AT THIS POINT THE HEAVIEST AND STEADIEST RAIN
APPEARS TO BE WINDING DOWN. WHAT WE/LL BE LEFT WITH IS SCATTERED TO
NUMEROUS SHOWERS TODAY AND A BIT LESS TONIGHT.

TUESDAY THE CORE OF THE UPPER LOW MOVES OVERHEAD. LOOK FOR PCPN TO
INCREASE IN COVERAGE AGAIN AS INSTABILITY ALOFT INCREASES A BIT DUE
STEEPENING LAPSE RATES COURTESY OF H5 TEMPS NEAR -30C MOVING OVER
THE CWA. THE COLDER AIR WILL REMAIN WITH US THROUGH TUESDAY NIGHT.
THAT/S WHEN WE COULD SEE SOME WET SNOW MIX IN WITH THE RAIN SHOWERS.
MINOR...LESS THAN AN INCH...ACCUMS SEEM POSSIBLE IN OSCEOLA/CLARE
COUNTIES TUESDAY NIGHT. THE UPPER LOW WILL BE VERY SLOW TO MOVE OUT
AND WE/LL SEE THE COOL SHOWERY PCPN CONTINUE WEDNESDAY AS A COUPLE
OF SHORT WAVES ROTATE AROUND THE UPPER LOW AND ACROSS LOWER MICHIGAN.

HIGHS WILL BE BELOW NORMAL THROUGH THE SHORT TERM RANGING FROM THE
MID 40S TO MID 50S.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

THE COLD UPPER LOW REMAINS OVERHEAD THROUGH THURSDAY THEN MOVES INTO
NEW ENGLAND/SRN QUEBEC FOR THE WEEKEND. A SLIGHT CHANCE OF LIGHT
RAIN AND SNOW SHOWERS WILL LINGER THROUGH ABOUT THURSDAY NIGHT WHILE
H8 TEMPS AROUND -7C AND CYCLONIC FLOW ARE STILL PRESENT... OTHERWISE
DRY BUT CHILLY WEATHER IS EXPECTED WITH SFC HIGH PRESSURE MOVING IN.

THIS WEEKEND WE WILL STILL BE ON THE WRN PERIPHERY OF THE BROAD NEW
ENGLAND UPPER LOW. THE CONFLUENT/SHEARING UPPER LEVEL FLOW OVERHEAD
ASSOCIATED WITH THIS FEATURE HELPS TO FEND OFF RAIN ASSOCIATED WITH
A SYSTEM MOVING EAST FROM THE CENTRAL PLAINS. GUIDANCE SHOWS QPF
REMAINING TO OUR SOUTH WITH WEAK SURFACE RIDGING PREVAILING OVER THE
WEEKEND. TEMPERATURES WILL RECOVER A BIT AND HIGHS IN THE 50S ARE
EXPECTED SATURDAY AND SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY)
ISSUED AT 1220 PM EDT MON APR 20 2015

MAINLY IFR/MVFR CONDITIONS WILL CONTINUE THROUGH MID TO LATE
AFTERNOON DUE TO LOW CIGS AND SCATTERED SHOWERS AND PATCHY FOG
BEFORE GRADUALLY IMPROVING TO VFR THIS EVENING AND OVERNIGHT.

IT WILL BE BREEZY THIS AFTERNOON WITH SW WINDS OF 15 TO 25 KTS WITH
GUSTS TO AROUND 30 KTS. SOUTHWEST TO WEST WINDS WILL STAY UP AROUND
15 TO 25 KTS OVERNIGHT AND THEN VEER TO THE WEST AND INCREASE TO 20
TO 25 KTS WITH GUSTS TO AROUND 30 KTS BY MID TO LATE TUESDAY MORNING.

SCATTERED LIGHT RAIN SHOWERS WILL LINGER OVERNIGHT AND THEN BECOME
MORE PREVALENT ON TUESDAY. MAINLY VFR CONDITIONS ARE ANTICIPATED
TUESDAY ALTHOUGH SOME PATCHY MVFR IS POSSIBLE DUE TO LOWER CIGS AND
HEAVIER SHOWERS.

&&

.MARINE...
ISSUED AT 752 AM EDT MON APR 20 2015

ADDED AREAS OF DENSE FOG TO THE NEARSHORE FORECAST TODAY. DESPITE
GOOD MIXING... DEW POINTS IN THE 40S OVER THE COLD LAKE WATERS IS
PRODUCING FOG PER POST SUNRISE WEB CAMS AT MKG/HOLLAND.

LEFT THE SMALL CRAFT ADVISORY AS IS SOUTH OF WHITEHALL. AS THE LOW
MOVES FARTHER AWAY...WINDS WILL INCREASE FROM THE SOUTHWEST AND
WAVES WILL ALSO RESPOND. A SMALL CRAFT ADVISORY MAY ALSO BE NEEDED
NORTH OF WHITEHALL TONIGHT.

&&

.HYDROLOGY...
ISSUED AT 1156 AM EDT MON APR 20 2015

WIDESPREAD RAINFALL THROUGH 8 AM THIS MORNING PRODUCED 0.50 TO 0.75
INCHES ACROSS MOST OF THE GRAND AND MUSKEGON RIVER BASINS. FURTHER
SOUTH ACROSS THE KALAMAZOO RIVER BASIN...RAINFALL AMOUNTS WERE
HIGHER IN THE 0.75 TO 1.00 INCH RANGE. AS EXPECTED...GRADUAL RIVER
RISES HAVE BEGUN ON MOST AREA RIVERS. GENERAL HYDRO THINKING HAS NOT
CHANGED MUCH...MOSTLY WITHIN BANK RISES ARE EXPECTED. A FEW SITES
COULD EXCEED BANKFULL. BUT WITH RAIN TODAY AND TONIGHT BEING OF THE
SCATTERED AND LIGHT VARIETY...SIGNIFICANT FLOODING IS NOT EXPECTED.

FORECAST RAINFALL TODAY AND TONIGHT IS IN THE 0.10 TO 0.25 INCH
RANGE. EVEN LIGHTER PRECIP AMOUNTS ARE EXPECTED TUESDAY
INTO WEDNESDAY. A SLIGHT CHANCE OF LIGHT RAIN AND SNOW WILL LINGER
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. BUT MAINLY DRY AND CHILLY
WEATHER IS EXPECTED TOWARD THE END OF THE WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

UPDATE...WDM
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...LAURENS
HYDROLOGY...EBW
MARINE...04







000
FXUS63 KGRR 201619
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1220 PM EDT MON APR 20 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EDT MON APR 20 2015

A CHILLY WEEK IS DEVELOPING AS LOW PRESSURE HAS MOVED OVER THE GREAT
LAKES. COOLER AIR WILL FLOW INTO WEST MICHIGAN BEHIND THE LOW. RAIN
SHOWERS MAY MIX WITH WET SNOW AT TIMES. MINOR ACCUMULATIONS ARE
POSSIBLE TUESDAY NIGHT NEAR US 10. HIGHS WILL BE IN THE MID 40S TO
MID 50S THROUGH THE END OF THE WEEK.

&&

.UPDATE...
ISSUED AT 1152 AM EDT MON APR 20 2015

OVERALL THE ONGOING FORECAST LOOKS FINE. I DID SOME MINOR
ADJUSTMENTS TO THE POPS BASED ON RECENT RADAR TRENDS AND
CONSIDERING THERE IS ANOTHER SHORTWAVE THAT MOVES INTO THE AREA
THIS EVENING TO HELP INCREASE THE SHOWER ACTIVITY. IT WILL BE
BREEZY TODAY THROUGH TUESDAY BUT I DO NOT BELIEVE IT WILL BE WINDY
ENOUGH FOR A WIND ADVISORY.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

FORECAST CONCERNS CONTINUE TO DEAL WITH THE EVOLUTION OF THE LOW
MOVING ACROSS LOWER MICHIGAN. OVERALL...THE FORECAST IS UNFOLDING AS
EXPECTED.

LOCAL AND REGIONAL RADAR SHOWS RAIN SHOWERS MOVING NORTH ACROSS THE
CWA. OVERALL COVERAGE THOUGH IS BEGINNING TO DECREASE SOUTH OF THE
MI/IN BORDER AS THE LOW MOVES NORTH. SREF SHOWS THAT PCPN WILL FILL
BACK IN ACROSS THE SOUTHERN CWA LATER THIS MORNING AS A SHORT WAVE
ALOFT PIVOTS TOWARD LOWER MICHIGAN BEFORE DIMINISHING AGAIN LATER
THIS AFTERNOON. AT THIS POINT THE HEAVIEST AND STEADIEST RAIN
APPEARS TO BE WINDING DOWN. WHAT WE/LL BE LEFT WITH IS SCATTERED TO
NUMEROUS SHOWERS TODAY AND A BIT LESS TONIGHT.

TUESDAY THE CORE OF THE UPPER LOW MOVES OVERHEAD. LOOK FOR PCPN TO
INCREASE IN COVERAGE AGAIN AS INSTABILITY ALOFT INCREASES A BIT DUE
STEEPENING LAPSE RATES COURTESY OF H5 TEMPS NEAR -30C MOVING OVER
THE CWA. THE COLDER AIR WILL REMAIN WITH US THROUGH TUESDAY NIGHT.
THAT/S WHEN WE COULD SEE SOME WET SNOW MIX IN WITH THE RAIN SHOWERS.
MINOR...LESS THAN AN INCH...ACCUMS SEEM POSSIBLE IN OSCEOLA/CLARE
COUNTIES TUESDAY NIGHT. THE UPPER LOW WILL BE VERY SLOW TO MOVE OUT
AND WE/LL SEE THE COOL SHOWERY PCPN CONTINUE WEDNESDAY AS A COUPLE
OF SHORT WAVES ROTATE AROUND THE UPPER LOW AND ACROSS LOWER MICHIGAN.

HIGHS WILL BE BELOW NORMAL THROUGH THE SHORT TERM RANGING FROM THE
MID 40S TO MID 50S.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

THE COLD UPPER LOW REMAINS OVERHEAD THROUGH THURSDAY THEN MOVES INTO
NEW ENGLAND/SRN QUEBEC FOR THE WEEKEND. A SLIGHT CHANCE OF LIGHT
RAIN AND SNOW SHOWERS WILL LINGER THROUGH ABOUT THURSDAY NIGHT WHILE
H8 TEMPS AROUND -7C AND CYCLONIC FLOW ARE STILL PRESENT... OTHERWISE
DRY BUT CHILLY WEATHER IS EXPECTED WITH SFC HIGH PRESSURE MOVING IN.

THIS WEEKEND WE WILL STILL BE ON THE WRN PERIPHERY OF THE BROAD NEW
ENGLAND UPPER LOW. THE CONFLUENT/SHEARING UPPER LEVEL FLOW OVERHEAD
ASSOCIATED WITH THIS FEATURE HELPS TO FEND OFF RAIN ASSOCIATED WITH
A SYSTEM MOVING EAST FROM THE CENTRAL PLAINS. GUIDANCE SHOWS QPF
REMAINING TO OUR SOUTH WITH WEAK SURFACE RIDGING PREVAILING OVER THE
WEEKEND. TEMPERATURES WILL RECOVER A BIT AND HIGHS IN THE 50S ARE
EXPECTED SATURDAY AND SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY)
ISSUED AT 1220 PM EDT MON APR 20 2015

MAINLY IFR/MVFR CONDITIONS WILL CONTINUE THROUGH MID TO LATE
AFTERNOON DUE TO LOW CIGS AND SCATTERED SHOWERS AND PATCHY FOG
BEFORE GRADUALLY IMPROVING TO VFR THIS EVENING AND OVERNIGHT.

IT WILL BE BREEZY THIS AFTERNOON WITH SW WINDS OF 15 TO 25 KTS WITH
GUSTS TO AROUND 30 KTS. SOUTHWEST TO WEST WINDS WILL STAY UP AROUND
15 TO 25 KTS OVERNIGHT AND THEN VEER TO THE WEST AND INCREASE TO 20
TO 25 KTS WITH GUSTS TO AROUND 30 KTS BY MID TO LATE TUESDAY MORNING.

SCATTERED LIGHT RAIN SHOWERS WILL LINGER OVERNIGHT AND THEN BECOME
MORE PREVALENT ON TUESDAY. MAINLY VFR CONDITIONS ARE ANTICIPATED
TUESDAY ALTHOUGH SOME PATCHY MVFR IS POSSIBLE DUE TO LOWER CIGS AND
HEAVIER SHOWERS.

&&

.MARINE...
ISSUED AT 752 AM EDT MON APR 20 2015

ADDED AREAS OF DENSE FOG TO THE NEARSHORE FORECAST TODAY. DESPITE
GOOD MIXING... DEW POINTS IN THE 40S OVER THE COLD LAKE WATERS IS
PRODUCING FOG PER POST SUNRISE WEB CAMS AT MKG/HOLLAND.

LEFT THE SMALL CRAFT ADVISORY AS IS SOUTH OF WHITEHALL. AS THE LOW
MOVES FARTHER AWAY...WINDS WILL INCREASE FROM THE SOUTHWEST AND
WAVES WILL ALSO RESPOND. A SMALL CRAFT ADVISORY MAY ALSO BE NEEDED
NORTH OF WHITEHALL TONIGHT.

&&

.HYDROLOGY...
ISSUED AT 1156 AM EDT MON APR 20 2015

WIDESPREAD RAINFALL THROUGH 8 AM THIS MORNING PRODUCED 0.50 TO 0.75
INCHES ACROSS MOST OF THE GRAND AND MUSKEGON RIVER BASINS. FURTHER
SOUTH ACROSS THE KALAMAZOO RIVER BASIN...RAINFALL AMOUNTS WERE
HIGHER IN THE 0.75 TO 1.00 INCH RANGE. AS EXPECTED...GRADUAL RIVER
RISES HAVE BEGUN ON MOST AREA RIVERS. GENERAL HYDRO THINKING HAS NOT
CHANGED MUCH...MOSTLY WITHIN BANK RISES ARE EXPECTED. A FEW SITES
COULD EXCEED BANKFULL. BUT WITH RAIN TODAY AND TONIGHT BEING OF THE
SCATTERED AND LIGHT VARIETY...SIGNIFICANT FLOODING IS NOT EXPECTED.

FORECAST RAINFALL TODAY AND TONIGHT IS IN THE 0.10 TO 0.25 INCH
RANGE. EVEN LIGHTER PRECIP AMOUNTS ARE EXPECTED TUESDAY
INTO WEDNESDAY. A SLIGHT CHANCE OF LIGHT RAIN AND SNOW WILL LINGER
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. BUT MAINLY DRY AND CHILLY
WEATHER IS EXPECTED TOWARD THE END OF THE WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

UPDATE...WDM
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...LAURENS
HYDROLOGY...EBW
MARINE...04







000
FXUS63 KGRR 201619
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1220 PM EDT MON APR 20 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EDT MON APR 20 2015

A CHILLY WEEK IS DEVELOPING AS LOW PRESSURE HAS MOVED OVER THE GREAT
LAKES. COOLER AIR WILL FLOW INTO WEST MICHIGAN BEHIND THE LOW. RAIN
SHOWERS MAY MIX WITH WET SNOW AT TIMES. MINOR ACCUMULATIONS ARE
POSSIBLE TUESDAY NIGHT NEAR US 10. HIGHS WILL BE IN THE MID 40S TO
MID 50S THROUGH THE END OF THE WEEK.

&&

.UPDATE...
ISSUED AT 1152 AM EDT MON APR 20 2015

OVERALL THE ONGOING FORECAST LOOKS FINE. I DID SOME MINOR
ADJUSTMENTS TO THE POPS BASED ON RECENT RADAR TRENDS AND
CONSIDERING THERE IS ANOTHER SHORTWAVE THAT MOVES INTO THE AREA
THIS EVENING TO HELP INCREASE THE SHOWER ACTIVITY. IT WILL BE
BREEZY TODAY THROUGH TUESDAY BUT I DO NOT BELIEVE IT WILL BE WINDY
ENOUGH FOR A WIND ADVISORY.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

FORECAST CONCERNS CONTINUE TO DEAL WITH THE EVOLUTION OF THE LOW
MOVING ACROSS LOWER MICHIGAN. OVERALL...THE FORECAST IS UNFOLDING AS
EXPECTED.

LOCAL AND REGIONAL RADAR SHOWS RAIN SHOWERS MOVING NORTH ACROSS THE
CWA. OVERALL COVERAGE THOUGH IS BEGINNING TO DECREASE SOUTH OF THE
MI/IN BORDER AS THE LOW MOVES NORTH. SREF SHOWS THAT PCPN WILL FILL
BACK IN ACROSS THE SOUTHERN CWA LATER THIS MORNING AS A SHORT WAVE
ALOFT PIVOTS TOWARD LOWER MICHIGAN BEFORE DIMINISHING AGAIN LATER
THIS AFTERNOON. AT THIS POINT THE HEAVIEST AND STEADIEST RAIN
APPEARS TO BE WINDING DOWN. WHAT WE/LL BE LEFT WITH IS SCATTERED TO
NUMEROUS SHOWERS TODAY AND A BIT LESS TONIGHT.

TUESDAY THE CORE OF THE UPPER LOW MOVES OVERHEAD. LOOK FOR PCPN TO
INCREASE IN COVERAGE AGAIN AS INSTABILITY ALOFT INCREASES A BIT DUE
STEEPENING LAPSE RATES COURTESY OF H5 TEMPS NEAR -30C MOVING OVER
THE CWA. THE COLDER AIR WILL REMAIN WITH US THROUGH TUESDAY NIGHT.
THAT/S WHEN WE COULD SEE SOME WET SNOW MIX IN WITH THE RAIN SHOWERS.
MINOR...LESS THAN AN INCH...ACCUMS SEEM POSSIBLE IN OSCEOLA/CLARE
COUNTIES TUESDAY NIGHT. THE UPPER LOW WILL BE VERY SLOW TO MOVE OUT
AND WE/LL SEE THE COOL SHOWERY PCPN CONTINUE WEDNESDAY AS A COUPLE
OF SHORT WAVES ROTATE AROUND THE UPPER LOW AND ACROSS LOWER MICHIGAN.

HIGHS WILL BE BELOW NORMAL THROUGH THE SHORT TERM RANGING FROM THE
MID 40S TO MID 50S.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

THE COLD UPPER LOW REMAINS OVERHEAD THROUGH THURSDAY THEN MOVES INTO
NEW ENGLAND/SRN QUEBEC FOR THE WEEKEND. A SLIGHT CHANCE OF LIGHT
RAIN AND SNOW SHOWERS WILL LINGER THROUGH ABOUT THURSDAY NIGHT WHILE
H8 TEMPS AROUND -7C AND CYCLONIC FLOW ARE STILL PRESENT... OTHERWISE
DRY BUT CHILLY WEATHER IS EXPECTED WITH SFC HIGH PRESSURE MOVING IN.

THIS WEEKEND WE WILL STILL BE ON THE WRN PERIPHERY OF THE BROAD NEW
ENGLAND UPPER LOW. THE CONFLUENT/SHEARING UPPER LEVEL FLOW OVERHEAD
ASSOCIATED WITH THIS FEATURE HELPS TO FEND OFF RAIN ASSOCIATED WITH
A SYSTEM MOVING EAST FROM THE CENTRAL PLAINS. GUIDANCE SHOWS QPF
REMAINING TO OUR SOUTH WITH WEAK SURFACE RIDGING PREVAILING OVER THE
WEEKEND. TEMPERATURES WILL RECOVER A BIT AND HIGHS IN THE 50S ARE
EXPECTED SATURDAY AND SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY)
ISSUED AT 1220 PM EDT MON APR 20 2015

MAINLY IFR/MVFR CONDITIONS WILL CONTINUE THROUGH MID TO LATE
AFTERNOON DUE TO LOW CIGS AND SCATTERED SHOWERS AND PATCHY FOG
BEFORE GRADUALLY IMPROVING TO VFR THIS EVENING AND OVERNIGHT.

IT WILL BE BREEZY THIS AFTERNOON WITH SW WINDS OF 15 TO 25 KTS WITH
GUSTS TO AROUND 30 KTS. SOUTHWEST TO WEST WINDS WILL STAY UP AROUND
15 TO 25 KTS OVERNIGHT AND THEN VEER TO THE WEST AND INCREASE TO 20
TO 25 KTS WITH GUSTS TO AROUND 30 KTS BY MID TO LATE TUESDAY MORNING.

SCATTERED LIGHT RAIN SHOWERS WILL LINGER OVERNIGHT AND THEN BECOME
MORE PREVALENT ON TUESDAY. MAINLY VFR CONDITIONS ARE ANTICIPATED
TUESDAY ALTHOUGH SOME PATCHY MVFR IS POSSIBLE DUE TO LOWER CIGS AND
HEAVIER SHOWERS.

&&

.MARINE...
ISSUED AT 752 AM EDT MON APR 20 2015

ADDED AREAS OF DENSE FOG TO THE NEARSHORE FORECAST TODAY. DESPITE
GOOD MIXING... DEW POINTS IN THE 40S OVER THE COLD LAKE WATERS IS
PRODUCING FOG PER POST SUNRISE WEB CAMS AT MKG/HOLLAND.

LEFT THE SMALL CRAFT ADVISORY AS IS SOUTH OF WHITEHALL. AS THE LOW
MOVES FARTHER AWAY...WINDS WILL INCREASE FROM THE SOUTHWEST AND
WAVES WILL ALSO RESPOND. A SMALL CRAFT ADVISORY MAY ALSO BE NEEDED
NORTH OF WHITEHALL TONIGHT.

&&

.HYDROLOGY...
ISSUED AT 1156 AM EDT MON APR 20 2015

WIDESPREAD RAINFALL THROUGH 8 AM THIS MORNING PRODUCED 0.50 TO 0.75
INCHES ACROSS MOST OF THE GRAND AND MUSKEGON RIVER BASINS. FURTHER
SOUTH ACROSS THE KALAMAZOO RIVER BASIN...RAINFALL AMOUNTS WERE
HIGHER IN THE 0.75 TO 1.00 INCH RANGE. AS EXPECTED...GRADUAL RIVER
RISES HAVE BEGUN ON MOST AREA RIVERS. GENERAL HYDRO THINKING HAS NOT
CHANGED MUCH...MOSTLY WITHIN BANK RISES ARE EXPECTED. A FEW SITES
COULD EXCEED BANKFULL. BUT WITH RAIN TODAY AND TONIGHT BEING OF THE
SCATTERED AND LIGHT VARIETY...SIGNIFICANT FLOODING IS NOT EXPECTED.

FORECAST RAINFALL TODAY AND TONIGHT IS IN THE 0.10 TO 0.25 INCH
RANGE. EVEN LIGHTER PRECIP AMOUNTS ARE EXPECTED TUESDAY
INTO WEDNESDAY. A SLIGHT CHANCE OF LIGHT RAIN AND SNOW WILL LINGER
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. BUT MAINLY DRY AND CHILLY
WEATHER IS EXPECTED TOWARD THE END OF THE WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

UPDATE...WDM
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...LAURENS
HYDROLOGY...EBW
MARINE...04







000
FXUS63 KGRR 201556
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1156 AM EDT MON APR 20 2015

LATEST UPDATE...
HYDRO

.SYNOPSIS...
ISSUED AT 330 AM EDT MON APR 20 2015

A CHILLY WEEK IS DEVELOPING AS LOW PRESSURE HAS MOVED OVER THE GREAT
LAKES. COOLER AIR WILL FLOW INTO WEST MICHIGAN BEHIND THE LOW. RAIN
SHOWERS MAY MIX WITH WET SNOW AT TIMES. MINOR ACCUMULATIONS ARE
POSSIBLE TUESDAY NIGHT NEAR US 10. HIGHS WILL BE IN THE MID 40S TO
MID 50S THROUGH THE END OF THE WEEK.

&&

.UPDATE...
ISSUED AT 1152 AM EDT MON APR 20 2015

OVERALL THE ONGOING FORECAST LOOKS FINE. I DID SOME MINOR
ADJUSTMENTS TO THE POPS BASED ON RECENT RADAR TRENDS AND
CONSIDERING THERE IS ANOTHER SHORTWAVE THAT MOVES INTO THE AREA
THIS EVENING TO HELP INCREASE THE SHOWER ACTIVITY. IT WILL BE
BREEZY TODAY THROUGH TUESDAY BUT I DO NOT BELIEVE IT WILL BE WINDY
ENOUGH FOR A WIND ADVISORY.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

FORECAST CONCERNS CONTINUE TO DEAL WITH THE EVOLUTION OF THE LOW
MOVING ACROSS LOWER MICHIGAN. OVERALL...THE FORECAST IS UNFOLDING AS
EXPECTED.

LOCAL AND REGIONAL RADAR SHOWS RAIN SHOWERS MOVING NORTH ACROSS THE
CWA. OVERALL COVERAGE THOUGH IS BEGINNING TO DECREASE SOUTH OF THE
MI/IN BORDER AS THE LOW MOVES NORTH. SREF SHOWS THAT PCPN WILL FILL
BACK IN ACROSS THE SOUTHERN CWA LATER THIS MORNING AS A SHORT WAVE
ALOFT PIVOTS TOWARD LOWER MICHIGAN BEFORE DIMINISHING AGAIN LATER
THIS AFTERNOON. AT THIS POINT THE HEAVIEST AND STEADIEST RAIN
APPEARS TO BE WINDING DOWN. WHAT WE/LL BE LEFT WITH IS SCATTERED TO
NUMEROUS SHOWERS TODAY AND A BIT LESS TONIGHT.

TUESDAY THE CORE OF THE UPPER LOW MOVES OVERHEAD. LOOK FOR PCPN TO
INCREASE IN COVERAGE AGAIN AS INSTABILITY ALOFT INCREASES A BIT DUE
STEEPENING LAPSE RATES COURTESY OF H5 TEMPS NEAR -30C MOVING OVER
THE CWA. THE COLDER AIR WILL REMAIN WITH US THROUGH TUESDAY NIGHT.
THAT/S WHEN WE COULD SEE SOME WET SNOW MIX IN WITH THE RAIN SHOWERS.
MINOR...LESS THAN AN INCH...ACCUMS SEEM POSSIBLE IN OSCEOLA/CLARE
COUNTIES TUESDAY NIGHT. THE UPPER LOW WILL BE VERY SLOW TO MOVE OUT
AND WE/LL SEE THE COOL SHOWERY PCPN CONTINUE WEDNESDAY AS A COUPLE
OF SHORT WAVES ROTATE AROUND THE UPPER LOW AND ACROSS LOWER MICHIGAN.

HIGHS WILL BE BELOW NORMAL THROUGH THE SHORT TERM RANGING FROM THE
MID 40S TO MID 50S.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

THE COLD UPPER LOW REMAINS OVERHEAD THROUGH THURSDAY THEN MOVES INTO
NEW ENGLAND/SRN QUEBEC FOR THE WEEKEND. A SLIGHT CHANCE OF LIGHT
RAIN AND SNOW SHOWERS WILL LINGER THROUGH ABOUT THURSDAY NIGHT WHILE
H8 TEMPS AROUND -7C AND CYCLONIC FLOW ARE STILL PRESENT... OTHERWISE
DRY BUT CHILLY WEATHER IS EXPECTED WITH SFC HIGH PRESSURE MOVING IN.

THIS WEEKEND WE WILL STILL BE ON THE WRN PERIPHERY OF THE BROAD NEW
ENGLAND UPPER LOW. THE CONFLUENT/SHEARING UPPER LEVEL FLOW OVERHEAD
ASSOCIATED WITH THIS FEATURE HELPS TO FEND OFF RAIN ASSOCIATED WITH
A SYSTEM MOVING EAST FROM THE CENTRAL PLAINS. GUIDANCE SHOWS QPF
REMAINING TO OUR SOUTH WITH WEAK SURFACE RIDGING PREVAILING OVER THE
WEEKEND. TEMPERATURES WILL RECOVER A BIT AND HIGHS IN THE 50S ARE
EXPECTED SATURDAY AND SUNDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 752 AM EDT MON APR 20 2015

NUMEROUS IFR CIGS WILL PREVAIL THIS MORNING WITH PRIMARILY MVFR
CIGS EXPECTED THIS AFTERNOON. SCATTERED RAIN SHOWERS AND AREAS OF
DRIZZLE WILL OCCASIONALLY DROP VSBYS TO 3-5 MILES AND MKG WILL
EXPERIENCE SOME FOG OFF THE LAKE REDUCING VSBYS BELOW ONE MILE AT
TIMES THIS MORNING. CONDITIONS ARE EXPECTED TO IMPROVE TO VFR
TONIGHT.

SOUTHWEST TO WEST WINDS WILL BE STRONG TODAY WITH SUSTAINED SPEEDS
AROUND 20 KTS AND GUSTS TO 35 KTS. THE WINDS WILL DIMINISH A BIT
TONIGHT BUT WILL STILL GUST TO 25 KTS.


&&

.MARINE...
ISSUED AT 752 AM EDT MON APR 20 2015

ADDED AREAS OF DENSE FOG TO THE NEARSHORE FORECAST TODAY. DESPITE
GOOD MIXING... DEW POINTS IN THE 40S OVER THE COLD LAKE WATERS IS
PRODUCING FOG PER POST SUNRISE WEB CAMS AT MKG/HOLLAND.

LEFT THE SMALL CRAFT ADVISORY AS IS SOUTH OF WHITEHALL. AS THE LOW
MOVES FARTHER AWAY...WINDS WILL INCREASE FROM THE SOUTHWEST AND
WAVES WILL ALSO RESPOND. A SMALL CRAFT ADVISORY MAY ALSO BE NEEDED
NORTH OF WHITEHALL TONIGHT.


&&

.HYDROLOGY...
ISSUED AT 1156 AM EDT MON APR 20 2015

WIDESPREAD RAINFALL THROUGH 8 AM THIS MORNING PRODUCED 0.50 TO 0.75
INCHES ACROSS MOST OF THE GRAND AND MUSKEGON RIVER BASINS. FURTHER
SOUTH ACROSS THE KALAMAZOO RIVER BASIN...RAINFALL AMOUNTS WERE
HIGHER IN THE 0.75 TO 1.00 INCH RANGE. AS EXPECTED...GRADUAL RIVER
RISES HAVE BEGUN ON MOST AREA RIVERS. GENERAL HYDRO THINKING HAS NOT
CHANGED MUCH...MOSTLY WITHIN BANK RISES ARE EXPECTED. A FEW SITES
COULD EXCEED BANKFULL. BUT WITH RAIN TODAY AND TONIGHT BEING OF THE
SCATTERED AND LIGHT VARIETY...SIGNIFICANT FLOODING IS NOT EXPECTED.

FORECAST RAINFALL TODAY AND TONIGHT IS IN THE 0.10 TO 0.25 INCH
RANGE. EVEN LIGHTER PRECIP AMOUNTS ARE EXPECTED TUESDAY
INTO WEDNESDAY. A SLIGHT CHANCE OF LIGHT RAIN AND SNOW WILL LINGER
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. BUT MAINLY DRY AND CHILLY
WEATHER IS EXPECTED TOWARD THE END OF THE WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

UPDATE...WDM
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...EBW
MARINE...04







000
FXUS63 KGRR 201556
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1156 AM EDT MON APR 20 2015

LATEST UPDATE...
HYDRO

.SYNOPSIS...
ISSUED AT 330 AM EDT MON APR 20 2015

A CHILLY WEEK IS DEVELOPING AS LOW PRESSURE HAS MOVED OVER THE GREAT
LAKES. COOLER AIR WILL FLOW INTO WEST MICHIGAN BEHIND THE LOW. RAIN
SHOWERS MAY MIX WITH WET SNOW AT TIMES. MINOR ACCUMULATIONS ARE
POSSIBLE TUESDAY NIGHT NEAR US 10. HIGHS WILL BE IN THE MID 40S TO
MID 50S THROUGH THE END OF THE WEEK.

&&

.UPDATE...
ISSUED AT 1152 AM EDT MON APR 20 2015

OVERALL THE ONGOING FORECAST LOOKS FINE. I DID SOME MINOR
ADJUSTMENTS TO THE POPS BASED ON RECENT RADAR TRENDS AND
CONSIDERING THERE IS ANOTHER SHORTWAVE THAT MOVES INTO THE AREA
THIS EVENING TO HELP INCREASE THE SHOWER ACTIVITY. IT WILL BE
BREEZY TODAY THROUGH TUESDAY BUT I DO NOT BELIEVE IT WILL BE WINDY
ENOUGH FOR A WIND ADVISORY.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

FORECAST CONCERNS CONTINUE TO DEAL WITH THE EVOLUTION OF THE LOW
MOVING ACROSS LOWER MICHIGAN. OVERALL...THE FORECAST IS UNFOLDING AS
EXPECTED.

LOCAL AND REGIONAL RADAR SHOWS RAIN SHOWERS MOVING NORTH ACROSS THE
CWA. OVERALL COVERAGE THOUGH IS BEGINNING TO DECREASE SOUTH OF THE
MI/IN BORDER AS THE LOW MOVES NORTH. SREF SHOWS THAT PCPN WILL FILL
BACK IN ACROSS THE SOUTHERN CWA LATER THIS MORNING AS A SHORT WAVE
ALOFT PIVOTS TOWARD LOWER MICHIGAN BEFORE DIMINISHING AGAIN LATER
THIS AFTERNOON. AT THIS POINT THE HEAVIEST AND STEADIEST RAIN
APPEARS TO BE WINDING DOWN. WHAT WE/LL BE LEFT WITH IS SCATTERED TO
NUMEROUS SHOWERS TODAY AND A BIT LESS TONIGHT.

TUESDAY THE CORE OF THE UPPER LOW MOVES OVERHEAD. LOOK FOR PCPN TO
INCREASE IN COVERAGE AGAIN AS INSTABILITY ALOFT INCREASES A BIT DUE
STEEPENING LAPSE RATES COURTESY OF H5 TEMPS NEAR -30C MOVING OVER
THE CWA. THE COLDER AIR WILL REMAIN WITH US THROUGH TUESDAY NIGHT.
THAT/S WHEN WE COULD SEE SOME WET SNOW MIX IN WITH THE RAIN SHOWERS.
MINOR...LESS THAN AN INCH...ACCUMS SEEM POSSIBLE IN OSCEOLA/CLARE
COUNTIES TUESDAY NIGHT. THE UPPER LOW WILL BE VERY SLOW TO MOVE OUT
AND WE/LL SEE THE COOL SHOWERY PCPN CONTINUE WEDNESDAY AS A COUPLE
OF SHORT WAVES ROTATE AROUND THE UPPER LOW AND ACROSS LOWER MICHIGAN.

HIGHS WILL BE BELOW NORMAL THROUGH THE SHORT TERM RANGING FROM THE
MID 40S TO MID 50S.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

THE COLD UPPER LOW REMAINS OVERHEAD THROUGH THURSDAY THEN MOVES INTO
NEW ENGLAND/SRN QUEBEC FOR THE WEEKEND. A SLIGHT CHANCE OF LIGHT
RAIN AND SNOW SHOWERS WILL LINGER THROUGH ABOUT THURSDAY NIGHT WHILE
H8 TEMPS AROUND -7C AND CYCLONIC FLOW ARE STILL PRESENT... OTHERWISE
DRY BUT CHILLY WEATHER IS EXPECTED WITH SFC HIGH PRESSURE MOVING IN.

THIS WEEKEND WE WILL STILL BE ON THE WRN PERIPHERY OF THE BROAD NEW
ENGLAND UPPER LOW. THE CONFLUENT/SHEARING UPPER LEVEL FLOW OVERHEAD
ASSOCIATED WITH THIS FEATURE HELPS TO FEND OFF RAIN ASSOCIATED WITH
A SYSTEM MOVING EAST FROM THE CENTRAL PLAINS. GUIDANCE SHOWS QPF
REMAINING TO OUR SOUTH WITH WEAK SURFACE RIDGING PREVAILING OVER THE
WEEKEND. TEMPERATURES WILL RECOVER A BIT AND HIGHS IN THE 50S ARE
EXPECTED SATURDAY AND SUNDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 752 AM EDT MON APR 20 2015

NUMEROUS IFR CIGS WILL PREVAIL THIS MORNING WITH PRIMARILY MVFR
CIGS EXPECTED THIS AFTERNOON. SCATTERED RAIN SHOWERS AND AREAS OF
DRIZZLE WILL OCCASIONALLY DROP VSBYS TO 3-5 MILES AND MKG WILL
EXPERIENCE SOME FOG OFF THE LAKE REDUCING VSBYS BELOW ONE MILE AT
TIMES THIS MORNING. CONDITIONS ARE EXPECTED TO IMPROVE TO VFR
TONIGHT.

SOUTHWEST TO WEST WINDS WILL BE STRONG TODAY WITH SUSTAINED SPEEDS
AROUND 20 KTS AND GUSTS TO 35 KTS. THE WINDS WILL DIMINISH A BIT
TONIGHT BUT WILL STILL GUST TO 25 KTS.


&&

.MARINE...
ISSUED AT 752 AM EDT MON APR 20 2015

ADDED AREAS OF DENSE FOG TO THE NEARSHORE FORECAST TODAY. DESPITE
GOOD MIXING... DEW POINTS IN THE 40S OVER THE COLD LAKE WATERS IS
PRODUCING FOG PER POST SUNRISE WEB CAMS AT MKG/HOLLAND.

LEFT THE SMALL CRAFT ADVISORY AS IS SOUTH OF WHITEHALL. AS THE LOW
MOVES FARTHER AWAY...WINDS WILL INCREASE FROM THE SOUTHWEST AND
WAVES WILL ALSO RESPOND. A SMALL CRAFT ADVISORY MAY ALSO BE NEEDED
NORTH OF WHITEHALL TONIGHT.


&&

.HYDROLOGY...
ISSUED AT 1156 AM EDT MON APR 20 2015

WIDESPREAD RAINFALL THROUGH 8 AM THIS MORNING PRODUCED 0.50 TO 0.75
INCHES ACROSS MOST OF THE GRAND AND MUSKEGON RIVER BASINS. FURTHER
SOUTH ACROSS THE KALAMAZOO RIVER BASIN...RAINFALL AMOUNTS WERE
HIGHER IN THE 0.75 TO 1.00 INCH RANGE. AS EXPECTED...GRADUAL RIVER
RISES HAVE BEGUN ON MOST AREA RIVERS. GENERAL HYDRO THINKING HAS NOT
CHANGED MUCH...MOSTLY WITHIN BANK RISES ARE EXPECTED. A FEW SITES
COULD EXCEED BANKFULL. BUT WITH RAIN TODAY AND TONIGHT BEING OF THE
SCATTERED AND LIGHT VARIETY...SIGNIFICANT FLOODING IS NOT EXPECTED.

FORECAST RAINFALL TODAY AND TONIGHT IS IN THE 0.10 TO 0.25 INCH
RANGE. EVEN LIGHTER PRECIP AMOUNTS ARE EXPECTED TUESDAY
INTO WEDNESDAY. A SLIGHT CHANCE OF LIGHT RAIN AND SNOW WILL LINGER
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. BUT MAINLY DRY AND CHILLY
WEATHER IS EXPECTED TOWARD THE END OF THE WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

UPDATE...WDM
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...EBW
MARINE...04






000
FXUS63 KGRR 201551
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1151 AM EDT MON APR 20 2015

LATEST UPDATE...
UPDATE

.SYNOPSIS...
ISSUED AT 330 AM EDT MON APR 20 2015

A CHILLY WEEK IS DEVELOPING AS LOW PRESSURE HAS MOVED OVER THE GREAT
LAKES. COOLER AIR WILL FLOW INTO WEST MICHIGAN BEHIND THE LOW. RAIN
SHOWERS MAY MIX WITH WET SNOW AT TIMES. MINOR ACCUMULATIONS ARE
POSSIBLE TUESDAY NIGHT NEAR US 10. HIGHS WILL BE IN THE MID 40S TO
MID 50S THROUGH THE END OF THE WEEK.

&&

.UPDATE...
ISSUED AT 1152 AM EDT MON APR 20 2015

OVERALL THE ONGOING FORECAST LOOKS FINE. I DID SOME MINOR
ADJUSTMENTS TO THE POPS BASED ON RECENT RADAR TRENDS AND
CONSIDERING THERE IS ANOTHER SHORTWAVE THAT MOVES INTO THE AREA
THIS EVENING TO HELP INCREASE THE SHOWER ACTIVITY. IT WILL BE
BREEZY TODAY THROUGH TUESDAY BUT I DO NOT BELIEVE IT WILL BE WINDY
ENOUGH FOR A WIND ADVISORY.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

FORECAST CONCERNS CONTINUE TO DEAL WITH THE EVOLUTION OF THE LOW
MOVING ACROSS LOWER MICHIGAN. OVERALL...THE FORECAST IS UNFOLDING AS
EXPECTED.

LOCAL AND REGIONAL RADAR SHOWS RAIN SHOWERS MOVING NORTH ACROSS THE
CWA. OVERALL COVERAGE THOUGH IS BEGINNING TO DECREASE SOUTH OF THE
MI/IN BORDER AS THE LOW MOVES NORTH. SREF SHOWS THAT PCPN WILL FILL
BACK IN ACROSS THE SOUTHERN CWA LATER THIS MORNING AS A SHORT WAVE
ALOFT PIVOTS TOWARD LOWER MICHIGAN BEFORE DIMINISHING AGAIN LATER
THIS AFTERNOON. AT THIS POINT THE HEAVIEST AND STEADIEST RAIN
APPEARS TO BE WINDING DOWN. WHAT WE/LL BE LEFT WITH IS SCATTERED TO
NUMEROUS SHOWERS TODAY AND A BIT LESS TONIGHT.

TUESDAY THE CORE OF THE UPPER LOW MOVES OVERHEAD. LOOK FOR PCPN TO
INCREASE IN COVERAGE AGAIN AS INSTABILITY ALOFT INCREASES A BIT DUE
STEEPENING LAPSE RATES COURTESY OF H5 TEMPS NEAR -30C MOVING OVER
THE CWA. THE COLDER AIR WILL REMAIN WITH US THROUGH TUESDAY NIGHT.
THAT/S WHEN WE COULD SEE SOME WET SNOW MIX IN WITH THE RAIN SHOWERS.
MINOR...LESS THAN AN INCH...ACCUMS SEEM POSSIBLE IN OSCEOLA/CLARE
COUNTIES TUESDAY NIGHT. THE UPPER LOW WILL BE VERY SLOW TO MOVE OUT
AND WE/LL SEE THE COOL SHOWERY PCPN CONTINUE WEDNESDAY AS A COUPLE
OF SHORT WAVES ROTATE AROUND THE UPPER LOW AND ACROSS LOWER MICHIGAN.

HIGHS WILL BE BELOW NORMAL THROUGH THE SHORT TERM RANGING FROM THE
MID 40S TO MID 50S.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

THE COLD UPPER LOW REMAINS OVERHEAD THROUGH THURSDAY THEN MOVES INTO
NEW ENGLAND/SRN QUEBEC FOR THE WEEKEND. A SLIGHT CHANCE OF LIGHT
RAIN AND SNOW SHOWERS WILL LINGER THROUGH ABOUT THURSDAY NIGHT WHILE
H8 TEMPS AROUND -7C AND CYCLONIC FLOW ARE STILL PRESENT... OTHERWISE
DRY BUT CHILLY WEATHER IS EXPECTED WITH SFC HIGH PRESSURE MOVING IN.

THIS WEEKEND WE WILL STILL BE ON THE WRN PERIPHERY OF THE BROAD NEW
ENGLAND UPPER LOW. THE CONFLUENT/SHEARING UPPER LEVEL FLOW OVERHEAD
ASSOCIATED WITH THIS FEATURE HELPS TO FEND OFF RAIN ASSOCIATED WITH
A SYSTEM MOVING EAST FROM THE CENTRAL PLAINS. GUIDANCE SHOWS QPF
REMAINING TO OUR SOUTH WITH WEAK SURFACE RIDGING PREVAILING OVER THE
WEEKEND. TEMPERATURES WILL RECOVER A BIT AND HIGHS IN THE 50S ARE
EXPECTED SATURDAY AND SUNDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 752 AM EDT MON APR 20 2015

NUMEROUS IFR CIGS WILL PREVAIL THIS MORNING WITH PRIMARILY MVFR
CIGS EXPECTED THIS AFTERNOON. SCATTERED RAIN SHOWERS AND AREAS OF
DRIZZLE WILL OCCASIONALLY DROP VSBYS TO 3-5 MILES AND MKG WILL
EXPERIENCE SOME FOG OFF THE LAKE REDUCING VSBYS BELOW ONE MILE AT
TIMES THIS MORNING. CONDITIONS ARE EXPECTED TO IMPROVE TO VFR
TONIGHT.

SOUTHWEST TO WEST WINDS WILL BE STRONG TODAY WITH SUSTAINED SPEEDS
AROUND 20 KTS AND GUSTS TO 35 KTS. THE WINDS WILL DIMINISH A BIT
TONIGHT BUT WILL STILL GUST TO 25 KTS.


&&

.MARINE...
ISSUED AT 752 AM EDT MON APR 20 2015

ADDED AREAS OF DENSE FOG TO THE NEARSHORE FORECAST TODAY. DESPITE
GOOD MIXING... DEW POINTS IN THE 40S OVER THE COLD LAKE WATERS IS
PRODUCING FOG PER POST SUNRISE WEB CAMS AT MKG/HOLLAND.

LEFT THE SMALL CRAFT ADVISORY AS IS SOUTH OF WHITEHALL. AS THE LOW
MOVES FARTHER AWAY...WINDS WILL INCREASE FROM THE SOUTHWEST AND
WAVES WILL ALSO RESPOND. A SMALL CRAFT ADVISORY MAY ALSO BE NEEDED
NORTH OF WHITEHALL TONIGHT.


&&

.HYDROLOGY...
ISSUED AT 1114 AM EDT SUN APR 19 2015

PERIODS OF RAIN ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON AND
AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. THE LIGHTER VARIETY OF
PRECIPITATION MAY EXTENT INTO MIDWEEK. THOUGH WE WILL SEE A DECENT
SOIL
SOAKING IT SHOULD NOT BE SUBSTANTIAL ENOUGH TO CREATE FLOODING
CONCERNS. GRADUAL BUT MINOR RISES ARE LIKELY...SUSPECTING THAT
THIS WOULD STAY WITHIN BANKS FOR MOST LOCATIONS. I WOULD NOT RULE
OUT A COUPLE OF SITES FLIRTING WITH ADVISORY STAGE AS WE GO INTO
TUESDAY...ESPECIALLY IF ANY MODERATE RAINFALL IS MORE PERSISTENT
WITH THE FIRST COUPLE OF ROUNDS OF MOISTURE. OTHERWISE...AREA
RIVERS ARE WELL BEHAVED THROUGH THE PERIOD.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

UPDATE...WDM
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...JAM
MARINE...04






000
FXUS63 KGRR 201152
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
752 AM EDT MON APR 20 2015

LATEST UPDATE...
AVIATION/MARINE

.SYNOPSIS...
ISSUED AT 330 AM EDT MON APR 20 2015

A CHILLY WEEK IS DEVELOPING AS LOW PRESSURE HAS MOVED OVER THE GREAT
LAKES. COOLER AIR WILL FLOW INTO WEST MICHIGAN BEHIND THE LOW. RAIN
SHOWERS MAY MIX WITH WET SNOW AT TIMES. MINOR ACCUMULATIONS ARE
POSSIBLE TUESDAY NIGHT NEAR US 10. HIGHS WILL BE IN THE MID 40S TO
MID 50S THROUGH THE END OF THE WEEK.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

FORECAST CONCERNS CONTINUE TO DEAL WITH THE EVOLUTION OF THE LOW
MOVING ACROSS LOWER MICHIGAN. OVERALL...THE FORECAST IS UNFOLDING AS
EXPECTED.

LOCAL AND REGIONAL RADAR SHOWS RAIN SHOWERS MOVING NORTH ACROSS THE
CWA. OVERALL COVERAGE THOUGH IS BEGINNING TO DECREASE SOUTH OF THE
MI/IN BORDER AS THE LOW MOVES NORTH. SREF SHOWS THAT PCPN WILL FILL
BACK IN ACROSS THE SOUTHERN CWA LATER THIS MORNING AS A SHORT WAVE
ALOFT PIVOTS TOWARD LOWER MICHIGAN BEFORE DIMINISHING AGAIN LATER
THIS AFTERNOON. AT THIS POINT THE HEAVIEST AND STEADIEST RAIN
APPEARS TO BE WINDING DOWN. WHAT WE/LL BE LEFT WITH IS SCATTERED TO
NUMEROUS SHOWERS TODAY AND A BIT LESS TONIGHT.

TUESDAY THE CORE OF THE UPPER LOW MOVES OVERHEAD. LOOK FOR PCPN TO
INCREASE IN COVERAGE AGAIN AS INSTABILITY ALOFT INCREASES A BIT DUE
STEEPENING LAPSE RATES COURTESY OF H5 TEMPS NEAR -30C MOVING OVER
THE CWA. THE COLDER AIR WILL REMAIN WITH US THROUGH TUESDAY NIGHT.
THAT/S WHEN WE COULD SEE SOME WET SNOW MIX IN WITH THE RAIN SHOWERS.
MINOR...LESS THAN AN INCH...ACCUMS SEEM POSSIBLE IN OSCEOLA/CLARE
COUNTIES TUESDAY NIGHT. THE UPPER LOW WILL BE VERY SLOW TO MOVE OUT
AND WE/LL SEE THE COOL SHOWERY PCPN CONTINUE WEDNESDAY AS A COUPLE
OF SHORT WAVES ROTATE AROUND THE UPPER LOW AND ACROSS LOWER MICHIGAN.

HIGHS WILL BE BELOW NORMAL THROUGH THE SHORT TERM RANGING FROM THE
MID 40S TO MID 50S.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

THE COLD UPPER LOW REMAINS OVERHEAD THROUGH THURSDAY THEN MOVES INTO
NEW ENGLAND/SRN QUEBEC FOR THE WEEKEND. A SLIGHT CHANCE OF LIGHT
RAIN AND SNOW SHOWERS WILL LINGER THROUGH ABOUT THURSDAY NIGHT WHILE
H8 TEMPS AROUND -7C AND CYCLONIC FLOW ARE STILL PRESENT... OTHERWISE
DRY BUT CHILLY WEATHER IS EXPECTED WITH SFC HIGH PRESSURE MOVING IN.

THIS WEEKEND WE WILL STILL BE ON THE WRN PERIPHERY OF THE BROAD NEW
ENGLAND UPPER LOW. THE CONFLUENT/SHEARING UPPER LEVEL FLOW OVERHEAD
ASSOCIATED WITH THIS FEATURE HELPS TO FEND OFF RAIN ASSOCIATED WITH
A SYSTEM MOVING EAST FROM THE CENTRAL PLAINS. GUIDANCE SHOWS QPF
REMAINING TO OUR SOUTH WITH WEAK SURFACE RIDGING PREVAILING OVER THE
WEEKEND. TEMPERATURES WILL RECOVER A BIT AND HIGHS IN THE 50S ARE
EXPECTED SATURDAY AND SUNDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 752 AM EDT MON APR 20 2015

NUMEROUS IFR CIGS WILL PREVAIL THIS MORNING WITH PRIMARILY MVFR
CIGS EXPECTED THIS AFTERNOON. SCATTERED RAIN SHOWERS AND AREAS OF
DRIZZLE WILL OCCASIONALLY DROP VSBYS TO 3-5 MILES AND MKG WILL
EXPERIENCE SOME FOG OFF THE LAKE REDUCING VSBYS BELOW ONE MILE AT
TIMES THIS MORNING. CONDITIONS ARE EXPECTED TO IMPROVE TO VFR
TONIGHT.

SOUTHWEST TO WEST WINDS WILL BE STRONG TODAY WITH SUSTAINED SPEEDS
AROUND 20 KTS AND GUSTS TO 35 KTS. THE WINDS WILL DIMINISH A BIT
TONIGHT BUT WILL STILL GUST TO 25 KTS.

&&

.MARINE...
ISSUED AT 752 AM EDT MON APR 20 2015

ADDED AREAS OF DENSE FOG TO THE NEARSHORE FORECAST TODAY. DESPITE
GOOD MIXING... DEW POINTS IN THE 40S OVER THE COLD LAKE WATERS IS
PRODUCING FOG PER POST SUNRISE WEB CAMS AT MKG/HOLLAND.

LEFT THE SMALL CRAFT ADVISORY AS IS SOUTH OF WHITEHALL. AS THE LOW
MOVES FARTHER AWAY...WINDS WILL INCREASE FROM THE SOUTHWEST AND
WAVES WILL ALSO RESPOND. A SMALL CRAFT ADVISORY MAY ALSO BE NEEDED
NORTH OF WHITEHALL TONIGHT.

&&

.HYDROLOGY...
ISSUED AT 1114 AM EDT SUN APR 19 2015

PERIODS OF RAIN ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON AND
AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. THE LIGHTER VARIETY OF
PRECIPITATION MAY EXTENT INTO MIDWEEK. THOUGH WE WILL SEE A DECENT
SOIL
SOAKING IT SHOULD NOT BE SUBSTANTIAL ENOUGH TO CREATE FLOODING
CONCERNS. GRADUAL BUT MINOR RISES ARE LIKELY...SUSPECTING THAT
THIS WOULD STAY WITHIN BANKS FOR MOST LOCATIONS. I WOULD NOT RULE
OUT A COUPLE OF SITES FLIRTING WITH ADVISORY STAGE AS WE GO INTO
TUESDAY...ESPECIALLY IF ANY MODERATE RAINFALL IS MORE PERSISTENT
WITH THE FIRST COUPLE OF ROUNDS OF MOISTURE. OTHERWISE...AREA
RIVERS ARE WELL BEHAVED THROUGH THE PERIOD.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...JAM
MARINE...04






000
FXUS63 KGRR 201152
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
752 AM EDT MON APR 20 2015

LATEST UPDATE...
AVIATION/MARINE

.SYNOPSIS...
ISSUED AT 330 AM EDT MON APR 20 2015

A CHILLY WEEK IS DEVELOPING AS LOW PRESSURE HAS MOVED OVER THE GREAT
LAKES. COOLER AIR WILL FLOW INTO WEST MICHIGAN BEHIND THE LOW. RAIN
SHOWERS MAY MIX WITH WET SNOW AT TIMES. MINOR ACCUMULATIONS ARE
POSSIBLE TUESDAY NIGHT NEAR US 10. HIGHS WILL BE IN THE MID 40S TO
MID 50S THROUGH THE END OF THE WEEK.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

FORECAST CONCERNS CONTINUE TO DEAL WITH THE EVOLUTION OF THE LOW
MOVING ACROSS LOWER MICHIGAN. OVERALL...THE FORECAST IS UNFOLDING AS
EXPECTED.

LOCAL AND REGIONAL RADAR SHOWS RAIN SHOWERS MOVING NORTH ACROSS THE
CWA. OVERALL COVERAGE THOUGH IS BEGINNING TO DECREASE SOUTH OF THE
MI/IN BORDER AS THE LOW MOVES NORTH. SREF SHOWS THAT PCPN WILL FILL
BACK IN ACROSS THE SOUTHERN CWA LATER THIS MORNING AS A SHORT WAVE
ALOFT PIVOTS TOWARD LOWER MICHIGAN BEFORE DIMINISHING AGAIN LATER
THIS AFTERNOON. AT THIS POINT THE HEAVIEST AND STEADIEST RAIN
APPEARS TO BE WINDING DOWN. WHAT WE/LL BE LEFT WITH IS SCATTERED TO
NUMEROUS SHOWERS TODAY AND A BIT LESS TONIGHT.

TUESDAY THE CORE OF THE UPPER LOW MOVES OVERHEAD. LOOK FOR PCPN TO
INCREASE IN COVERAGE AGAIN AS INSTABILITY ALOFT INCREASES A BIT DUE
STEEPENING LAPSE RATES COURTESY OF H5 TEMPS NEAR -30C MOVING OVER
THE CWA. THE COLDER AIR WILL REMAIN WITH US THROUGH TUESDAY NIGHT.
THAT/S WHEN WE COULD SEE SOME WET SNOW MIX IN WITH THE RAIN SHOWERS.
MINOR...LESS THAN AN INCH...ACCUMS SEEM POSSIBLE IN OSCEOLA/CLARE
COUNTIES TUESDAY NIGHT. THE UPPER LOW WILL BE VERY SLOW TO MOVE OUT
AND WE/LL SEE THE COOL SHOWERY PCPN CONTINUE WEDNESDAY AS A COUPLE
OF SHORT WAVES ROTATE AROUND THE UPPER LOW AND ACROSS LOWER MICHIGAN.

HIGHS WILL BE BELOW NORMAL THROUGH THE SHORT TERM RANGING FROM THE
MID 40S TO MID 50S.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

THE COLD UPPER LOW REMAINS OVERHEAD THROUGH THURSDAY THEN MOVES INTO
NEW ENGLAND/SRN QUEBEC FOR THE WEEKEND. A SLIGHT CHANCE OF LIGHT
RAIN AND SNOW SHOWERS WILL LINGER THROUGH ABOUT THURSDAY NIGHT WHILE
H8 TEMPS AROUND -7C AND CYCLONIC FLOW ARE STILL PRESENT... OTHERWISE
DRY BUT CHILLY WEATHER IS EXPECTED WITH SFC HIGH PRESSURE MOVING IN.

THIS WEEKEND WE WILL STILL BE ON THE WRN PERIPHERY OF THE BROAD NEW
ENGLAND UPPER LOW. THE CONFLUENT/SHEARING UPPER LEVEL FLOW OVERHEAD
ASSOCIATED WITH THIS FEATURE HELPS TO FEND OFF RAIN ASSOCIATED WITH
A SYSTEM MOVING EAST FROM THE CENTRAL PLAINS. GUIDANCE SHOWS QPF
REMAINING TO OUR SOUTH WITH WEAK SURFACE RIDGING PREVAILING OVER THE
WEEKEND. TEMPERATURES WILL RECOVER A BIT AND HIGHS IN THE 50S ARE
EXPECTED SATURDAY AND SUNDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 752 AM EDT MON APR 20 2015

NUMEROUS IFR CIGS WILL PREVAIL THIS MORNING WITH PRIMARILY MVFR
CIGS EXPECTED THIS AFTERNOON. SCATTERED RAIN SHOWERS AND AREAS OF
DRIZZLE WILL OCCASIONALLY DROP VSBYS TO 3-5 MILES AND MKG WILL
EXPERIENCE SOME FOG OFF THE LAKE REDUCING VSBYS BELOW ONE MILE AT
TIMES THIS MORNING. CONDITIONS ARE EXPECTED TO IMPROVE TO VFR
TONIGHT.

SOUTHWEST TO WEST WINDS WILL BE STRONG TODAY WITH SUSTAINED SPEEDS
AROUND 20 KTS AND GUSTS TO 35 KTS. THE WINDS WILL DIMINISH A BIT
TONIGHT BUT WILL STILL GUST TO 25 KTS.

&&

.MARINE...
ISSUED AT 752 AM EDT MON APR 20 2015

ADDED AREAS OF DENSE FOG TO THE NEARSHORE FORECAST TODAY. DESPITE
GOOD MIXING... DEW POINTS IN THE 40S OVER THE COLD LAKE WATERS IS
PRODUCING FOG PER POST SUNRISE WEB CAMS AT MKG/HOLLAND.

LEFT THE SMALL CRAFT ADVISORY AS IS SOUTH OF WHITEHALL. AS THE LOW
MOVES FARTHER AWAY...WINDS WILL INCREASE FROM THE SOUTHWEST AND
WAVES WILL ALSO RESPOND. A SMALL CRAFT ADVISORY MAY ALSO BE NEEDED
NORTH OF WHITEHALL TONIGHT.

&&

.HYDROLOGY...
ISSUED AT 1114 AM EDT SUN APR 19 2015

PERIODS OF RAIN ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON AND
AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. THE LIGHTER VARIETY OF
PRECIPITATION MAY EXTENT INTO MIDWEEK. THOUGH WE WILL SEE A DECENT
SOIL
SOAKING IT SHOULD NOT BE SUBSTANTIAL ENOUGH TO CREATE FLOODING
CONCERNS. GRADUAL BUT MINOR RISES ARE LIKELY...SUSPECTING THAT
THIS WOULD STAY WITHIN BANKS FOR MOST LOCATIONS. I WOULD NOT RULE
OUT A COUPLE OF SITES FLIRTING WITH ADVISORY STAGE AS WE GO INTO
TUESDAY...ESPECIALLY IF ANY MODERATE RAINFALL IS MORE PERSISTENT
WITH THE FIRST COUPLE OF ROUNDS OF MOISTURE. OTHERWISE...AREA
RIVERS ARE WELL BEHAVED THROUGH THE PERIOD.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...JAM
MARINE...04







000
FXUS63 KDTX 201138
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
738 AM EDT MON APR 20 2015


.AVIATION...

LOW PRESSURE LIFTING NORTH THROUGH WESTERN MI WILL BRING GUSTY WINDS
AND RAIN SHOWERS INTO THE REGION TODAY. OUTSIDE OF AN INITIAL POP OF
WIND GUSTING TO AROUND 30 KNOTS RIGHT BEHIND THE NORTHBOUND WARM
FRONT...SW WINDS WILL GUST TO AROUND 25 KNOTS THIS MORNING BEFORE
INCREASING TO 30-35 KNOTS THIS AFTERNOON. CEILINGS WILL VARY THROUGH
THE DAY WITH THE PASSAGE OF THE WARM FRONT...INCREASING COVERAGE OF
RAIN SHOWERS...THEN A COLD FRONTAL PASSAGE LATE THIS AFTERNOON. WILL
BEGIN THE DAY WITH IFR/MVFR BEFORE IMPROVING TO VFR THIS EVENING
THROUGH THE OVERNIGHT.

FOR DTW...WIND GUSTS WITHIN THE SW FLOW OF THE WARM SECTOR WILL TOP
25 KNOTS INTO THE EVENING HOURS BEFORE RELAXING OVERNIGHT...BUT
STILL REMAINING ELEVATED AROUND 10 KNOTS DUE TO CONTINUED MIXING. A
FEW SPOTTY SHOWERS COULD OCCUR THROUGH THE EARLY PART OF THE DAY
BEFORE AN APPROACHING COLD FRONT INCREASES RAIN COVERAGE FROM ABOUT
17-21Z. THERE IS A CHANCE WE COULD SEE A FEW THUNDERSTORMS BUT
CONFIDENCE IS TOO LOW TO INCLUDE IN THE TAFS.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS AOB 5KFT THROUGH TONIGHT.

* LOW IN THUNDERSTORMS THIS AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 353 AM EDT MON APR 20 2015

SHORT TERM...TODAY AND TONIGHT

THE WELL ADVERTISED STRONG LOW PRESSURE SYSTEM HAS LIFTED INTO SW
LOWER MI AS OF 07Z THIS MORNING. IT WILL CONTINUE NORTHWARD REACHING
ONTARIO BY 00Z THIS EVENING. ALTHOUGH THE MAIN WING OF ISENTROPIC
ASCENT NORTH OF THE WARM FRONT AND COLOCATED RIBBON OF ENHANCED
MOISTURE IS NORTH OF SE MI...ELEVATED MOISTURE VALUES WILL LINGER
INTO THE EARLY AFTERNOON AS IT APPEARS THE EASTERN PORTION OF THE
CWA SHOULD RESIDE IN THE WARM SECTOR FOR SEVERAL HOURS. HOW THE
AFTERNOON WILL SHAPE UP WILL DEPEND ON A COMPACT SHORTWAVE ROTATING
AROUND THE BASE THE MID LEVEL TROUGH WHICH IS OVER THE UPPER
MISSISSIPPI VALLEY AND WILL SWING THROUGH THE OHIO VALLEY LATER
TODAY. THIS SHORTWAVE IS FORECAST TO LIFT SOMEWHERE THROUGH SE LOWER
MI OR WESTERN LAKE ERIE. THIS HAS BIG IMPLICATIONS ON THE FORECAST
DUE TO THE TIMING OF THE COLD FRONT THIS SECONDARY LOW WILL PULL
THROUGH THE AREA. CURRENTLY MODELS HAVE THE TIMING FAIRLY WELL
PEGGED DOWN TO THE 18-21Z TIMEFRAME. THIS WOULD ALLOW ENOUGH DIURNAL
HEATING TO POTENTIALLY BUILD UP A FEW HUNDRED J/KG OF CAPE AHEAD OF
THE APPROACHING COLD FRONT WITH VERY FAVORABLE LL LAPSE RATES AND
DEEP LAYER OF STRONG SW FLOW WITH SPEED SHEAR SETTING UP IN THE WARM
SECTOR. SPC HAS EXPANDED THE MARGINAL AREA TO INCLUDE A SLIVER OF
EXTREME EASTERN LOWER MI...EAST OF A LINE FROM ABOUT ADRIAN TO PORT
HURON. THERE IS CONCERN AS TO WHETHER THIS WILL ACTUALLY CONCERN AS
THE NAM/GEMREG/HRRR/ETC... SUGGEST THAT THE LL JET MAX WILL DRIFT
EASTWARD AND IGNITE THE COLD FRONT JUST SE OF MI LEAVING US WITH
ONLY RESIDUAL SHOWERS AND ISOLATED RUMBLES OF THUNDER AS THE FRONTAL
BOUNDARIES OCCLUDE AND SLIDE THROUGH THE AREA WITH THE TRIPLE POINT
STAYING SOUTH. AFTER SEVERAL MODEL RUNS TRENDING WESTWARD...THE
RECENT RUNS ARE STALLING IF NOT SHIFTING SLIGHTLY FURTHER EAST WHICH
LENDS CREDENCE THUNDERSTORM POTENTIAL DOUBTS. OVERALL THINK WE WILL
GET BRUSHED WITH SOME THUNDERSTORMS BUT THE BETTER ORGANIZED STORMS
WILL LIKELY STAY OUT OF THE AREA.

IN ADDITION TO COLD FRONTAL THUNDERSTORM POTENTIAL...WINDS WILL BE
QUITE GUSTY THROUGH THE DAY. THE DEEP MIXED LAYER WITH 900MB WINDS
MAKING A RUN AT 40 KNOTS WILL KEEP SW SFC FLOW AROUND 20KT WITH
GUSTS APPROACHING 35 KNOTS...ESPECIALLY EARLY THIS AFTERNOON EAST OF
THE FRONT.

AS THE FOR THE REST OF THE EVENING AND INTO THE OVERNIGHT...THE COLD
FRONT...OR OCCLUDED FRONT...WILL USHER IN MUCH COOLER AIR WHILE
KEEPING THE MIXED LAYER IN TACK THROUGH THE NIGHT WHICH WILL IN TURN
KEEP WINDS ELEVATED. THE ENHANCED MOISTURE PLUME WILL BE SHUNTED
EAST BUT SCATTERED SHOWERS WILL LINGER THROUGH THE OVERNIGHT AS CAA
RESULTS IN MORE FAVORABLE MID LEVEL LAPSE RATES. THE MIXING AND
CLOUD COVER WILL KEEP MIN TEMPS UP AROUND 40 FOR MOST LOCATIONS.

LONG TERM...

CLOSED UPPER LOW WILL REMAIN PARKED OVERHEAD THROUGH MIDWEEK.
EMBEDDED SHORTWAVES WILL BRING EPISODIC SHOWER ACTIVITY, THE TIMING
OF WHICH WILL REMAIN INHERENTLY ILL-DEFINED OUTSIDE OF 48 HOURS. A
COLD COLUMN AND CLOUD COVER WILL KEEP TEMPERATURES SOLIDLY BELOW
NORMAL.

LOW CENTER WILL MEANDER FROM INTERNATIONAL FALLS THIS AFTN TO THE
STRAITS BY MIDDAY TUESDAY. APRIL INSOLATION AND VERY COLD H5 TEMPS
WITHIN THE MID-LEVEL COLD POOL OF -30C WILL RESULT IN A DEEP MIXED
LAYER PERHAPS APPROACHING 600MB. ROBUST WSW WIND FIELD WITHIN THIS
VERY WELL-MIXED ENVIRONMENT WILL SET THE STAGE FOR WIDESPREAD WIND
GUSTS IN EXCESS OF 30 KNOTS FOR THE BALANCE OF TUESDAY AFTERNOON.
THE TRADE-OFF OF THE DEEP MIXING WILL BE TEMPERATURES REACHING THE
LOW 50S IN SPITE OF SUB-ZERO 850MB TEMPERATURES. SUFFICIENT MID-
LEVEL MOISTURE RESIDING IN THE 800-600MB LAYER WILL RESULT IN, AT
MINIMUM, WIDESPREAD AFTERNOON CLOUDS. MODELS ALSO POINT TO MID-
MORNING SHOWER GENERATION AS WELL, GIVEN A FEW HUNDRED J/KG CAPE
AVAILABLE FOR SURFACE BASED PARCELS. PASSING ELONGATED H4 PV ANOMALY
WILL PROVIDE BROAD SCALE ASCENT WHILE INLAND TROUGHING HELPS IS
NOTED TO HELP FOCUS ACTIVITY ALONG/NORTH OF M59. CLASSIC INVERTED V
THERMODYNAMIC PROFILE WILL ALLOW SHOWERS TO POTENTIALLY PRODUCE WIND
GUSTS OF 45 KTS.

LOSS OF DIURNAL HEATING WILL MEAN AN END TO SHOWERS TUESDAY EVENING.
THE GRADIENT WILL REMAIN ELEVATED AS BROAD LOW PRESSURE REMAINS
CENTERED OVER THE GREAT LAKES. COMBINED WITH CLOUDS, LOW
TEMPERATURES WILL BE COLD - BUT NOT AS COLD AS THEY COULD BE GIVEN
THE AIRMASS. PREFER NAM12 DEPICTION OF 34-38F TUESDAY NIGHT.

LITTLE CHANGE IN SYNOPTIC SCALE REGIME FOR WEDNESDAY, MEANING
CONTINUED DIURNALLY DRIVEN BOUNDARY LAYER CLOUD COVER AND AFTERNOON
WIND GUSTS IN THE 25-30 KT RANGE FROM THE WEST. BETTER LOW-LEVEL
MOISTURE QUALITY WILL BE OFFSET BY LACK OF FOCUSED FORCING, BUT HAVE
TO RESPECT POTENTIAL WITH A LOW END CHC POP. THE MOST NOTEWORTHY
CHANGE BY WED WILL BE POSITION OF THE THERMAL TROUGH OVERHEAD AS H85
TEMPERATURES FALL TO -6 TO -7C SUPPORTING HIGHS IN THE MID 40S AND
WIND CHILLS IN THE MID 30S.

MARINE...

FRESH TO LOCALLY STRONG SOUTHEAST WINDS WILL VEER TO THE SOUTHWEST
THROUGH TODAY. A FEW GUSTS TO NEAR GALES WILL BE POSSIBLE...MAINLY
IN NEARSHORE ZONES INCLUDING LAKE SAINT CLAIR AND ERIE. SMALL CRAFT
ADVISORIES THEREFORE REMAIN IN EFFECT FOR ALL NEARSHORE ZONES.
BREEZY WESTERLY WINDS WILL PERSIST THROUGH MIDWEEK AS CONDITIONS
REMAIN RELATIVELY STATIC WITH LOW PRESSURE PARKED OVER THE GREAT
LAKES. ADDITIONAL SMALL CRAFT ADVISORIES FOR WIND WILL LIKELY BE
NEEDED ON TUESDAY AND POSSIBLY ONCE MORE ON WEDNESDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LHZ421-422-
     441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LEZ444.

&&

$$

AVIATION.....DRK
SHORT TERM...DRK
LONG TERM....JVC
MARINE.......JVC


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).



000
FXUS63 KDTX 201138
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
738 AM EDT MON APR 20 2015


.AVIATION...

LOW PRESSURE LIFTING NORTH THROUGH WESTERN MI WILL BRING GUSTY WINDS
AND RAIN SHOWERS INTO THE REGION TODAY. OUTSIDE OF AN INITIAL POP OF
WIND GUSTING TO AROUND 30 KNOTS RIGHT BEHIND THE NORTHBOUND WARM
FRONT...SW WINDS WILL GUST TO AROUND 25 KNOTS THIS MORNING BEFORE
INCREASING TO 30-35 KNOTS THIS AFTERNOON. CEILINGS WILL VARY THROUGH
THE DAY WITH THE PASSAGE OF THE WARM FRONT...INCREASING COVERAGE OF
RAIN SHOWERS...THEN A COLD FRONTAL PASSAGE LATE THIS AFTERNOON. WILL
BEGIN THE DAY WITH IFR/MVFR BEFORE IMPROVING TO VFR THIS EVENING
THROUGH THE OVERNIGHT.

FOR DTW...WIND GUSTS WITHIN THE SW FLOW OF THE WARM SECTOR WILL TOP
25 KNOTS INTO THE EVENING HOURS BEFORE RELAXING OVERNIGHT...BUT
STILL REMAINING ELEVATED AROUND 10 KNOTS DUE TO CONTINUED MIXING. A
FEW SPOTTY SHOWERS COULD OCCUR THROUGH THE EARLY PART OF THE DAY
BEFORE AN APPROACHING COLD FRONT INCREASES RAIN COVERAGE FROM ABOUT
17-21Z. THERE IS A CHANCE WE COULD SEE A FEW THUNDERSTORMS BUT
CONFIDENCE IS TOO LOW TO INCLUDE IN THE TAFS.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS AOB 5KFT THROUGH TONIGHT.

* LOW IN THUNDERSTORMS THIS AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 353 AM EDT MON APR 20 2015

SHORT TERM...TODAY AND TONIGHT

THE WELL ADVERTISED STRONG LOW PRESSURE SYSTEM HAS LIFTED INTO SW
LOWER MI AS OF 07Z THIS MORNING. IT WILL CONTINUE NORTHWARD REACHING
ONTARIO BY 00Z THIS EVENING. ALTHOUGH THE MAIN WING OF ISENTROPIC
ASCENT NORTH OF THE WARM FRONT AND COLOCATED RIBBON OF ENHANCED
MOISTURE IS NORTH OF SE MI...ELEVATED MOISTURE VALUES WILL LINGER
INTO THE EARLY AFTERNOON AS IT APPEARS THE EASTERN PORTION OF THE
CWA SHOULD RESIDE IN THE WARM SECTOR FOR SEVERAL HOURS. HOW THE
AFTERNOON WILL SHAPE UP WILL DEPEND ON A COMPACT SHORTWAVE ROTATING
AROUND THE BASE THE MID LEVEL TROUGH WHICH IS OVER THE UPPER
MISSISSIPPI VALLEY AND WILL SWING THROUGH THE OHIO VALLEY LATER
TODAY. THIS SHORTWAVE IS FORECAST TO LIFT SOMEWHERE THROUGH SE LOWER
MI OR WESTERN LAKE ERIE. THIS HAS BIG IMPLICATIONS ON THE FORECAST
DUE TO THE TIMING OF THE COLD FRONT THIS SECONDARY LOW WILL PULL
THROUGH THE AREA. CURRENTLY MODELS HAVE THE TIMING FAIRLY WELL
PEGGED DOWN TO THE 18-21Z TIMEFRAME. THIS WOULD ALLOW ENOUGH DIURNAL
HEATING TO POTENTIALLY BUILD UP A FEW HUNDRED J/KG OF CAPE AHEAD OF
THE APPROACHING COLD FRONT WITH VERY FAVORABLE LL LAPSE RATES AND
DEEP LAYER OF STRONG SW FLOW WITH SPEED SHEAR SETTING UP IN THE WARM
SECTOR. SPC HAS EXPANDED THE MARGINAL AREA TO INCLUDE A SLIVER OF
EXTREME EASTERN LOWER MI...EAST OF A LINE FROM ABOUT ADRIAN TO PORT
HURON. THERE IS CONCERN AS TO WHETHER THIS WILL ACTUALLY CONCERN AS
THE NAM/GEMREG/HRRR/ETC... SUGGEST THAT THE LL JET MAX WILL DRIFT
EASTWARD AND IGNITE THE COLD FRONT JUST SE OF MI LEAVING US WITH
ONLY RESIDUAL SHOWERS AND ISOLATED RUMBLES OF THUNDER AS THE FRONTAL
BOUNDARIES OCCLUDE AND SLIDE THROUGH THE AREA WITH THE TRIPLE POINT
STAYING SOUTH. AFTER SEVERAL MODEL RUNS TRENDING WESTWARD...THE
RECENT RUNS ARE STALLING IF NOT SHIFTING SLIGHTLY FURTHER EAST WHICH
LENDS CREDENCE THUNDERSTORM POTENTIAL DOUBTS. OVERALL THINK WE WILL
GET BRUSHED WITH SOME THUNDERSTORMS BUT THE BETTER ORGANIZED STORMS
WILL LIKELY STAY OUT OF THE AREA.

IN ADDITION TO COLD FRONTAL THUNDERSTORM POTENTIAL...WINDS WILL BE
QUITE GUSTY THROUGH THE DAY. THE DEEP MIXED LAYER WITH 900MB WINDS
MAKING A RUN AT 40 KNOTS WILL KEEP SW SFC FLOW AROUND 20KT WITH
GUSTS APPROACHING 35 KNOTS...ESPECIALLY EARLY THIS AFTERNOON EAST OF
THE FRONT.

AS THE FOR THE REST OF THE EVENING AND INTO THE OVERNIGHT...THE COLD
FRONT...OR OCCLUDED FRONT...WILL USHER IN MUCH COOLER AIR WHILE
KEEPING THE MIXED LAYER IN TACK THROUGH THE NIGHT WHICH WILL IN TURN
KEEP WINDS ELEVATED. THE ENHANCED MOISTURE PLUME WILL BE SHUNTED
EAST BUT SCATTERED SHOWERS WILL LINGER THROUGH THE OVERNIGHT AS CAA
RESULTS IN MORE FAVORABLE MID LEVEL LAPSE RATES. THE MIXING AND
CLOUD COVER WILL KEEP MIN TEMPS UP AROUND 40 FOR MOST LOCATIONS.

LONG TERM...

CLOSED UPPER LOW WILL REMAIN PARKED OVERHEAD THROUGH MIDWEEK.
EMBEDDED SHORTWAVES WILL BRING EPISODIC SHOWER ACTIVITY, THE TIMING
OF WHICH WILL REMAIN INHERENTLY ILL-DEFINED OUTSIDE OF 48 HOURS. A
COLD COLUMN AND CLOUD COVER WILL KEEP TEMPERATURES SOLIDLY BELOW
NORMAL.

LOW CENTER WILL MEANDER FROM INTERNATIONAL FALLS THIS AFTN TO THE
STRAITS BY MIDDAY TUESDAY. APRIL INSOLATION AND VERY COLD H5 TEMPS
WITHIN THE MID-LEVEL COLD POOL OF -30C WILL RESULT IN A DEEP MIXED
LAYER PERHAPS APPROACHING 600MB. ROBUST WSW WIND FIELD WITHIN THIS
VERY WELL-MIXED ENVIRONMENT WILL SET THE STAGE FOR WIDESPREAD WIND
GUSTS IN EXCESS OF 30 KNOTS FOR THE BALANCE OF TUESDAY AFTERNOON.
THE TRADE-OFF OF THE DEEP MIXING WILL BE TEMPERATURES REACHING THE
LOW 50S IN SPITE OF SUB-ZERO 850MB TEMPERATURES. SUFFICIENT MID-
LEVEL MOISTURE RESIDING IN THE 800-600MB LAYER WILL RESULT IN, AT
MINIMUM, WIDESPREAD AFTERNOON CLOUDS. MODELS ALSO POINT TO MID-
MORNING SHOWER GENERATION AS WELL, GIVEN A FEW HUNDRED J/KG CAPE
AVAILABLE FOR SURFACE BASED PARCELS. PASSING ELONGATED H4 PV ANOMALY
WILL PROVIDE BROAD SCALE ASCENT WHILE INLAND TROUGHING HELPS IS
NOTED TO HELP FOCUS ACTIVITY ALONG/NORTH OF M59. CLASSIC INVERTED V
THERMODYNAMIC PROFILE WILL ALLOW SHOWERS TO POTENTIALLY PRODUCE WIND
GUSTS OF 45 KTS.

LOSS OF DIURNAL HEATING WILL MEAN AN END TO SHOWERS TUESDAY EVENING.
THE GRADIENT WILL REMAIN ELEVATED AS BROAD LOW PRESSURE REMAINS
CENTERED OVER THE GREAT LAKES. COMBINED WITH CLOUDS, LOW
TEMPERATURES WILL BE COLD - BUT NOT AS COLD AS THEY COULD BE GIVEN
THE AIRMASS. PREFER NAM12 DEPICTION OF 34-38F TUESDAY NIGHT.

LITTLE CHANGE IN SYNOPTIC SCALE REGIME FOR WEDNESDAY, MEANING
CONTINUED DIURNALLY DRIVEN BOUNDARY LAYER CLOUD COVER AND AFTERNOON
WIND GUSTS IN THE 25-30 KT RANGE FROM THE WEST. BETTER LOW-LEVEL
MOISTURE QUALITY WILL BE OFFSET BY LACK OF FOCUSED FORCING, BUT HAVE
TO RESPECT POTENTIAL WITH A LOW END CHC POP. THE MOST NOTEWORTHY
CHANGE BY WED WILL BE POSITION OF THE THERMAL TROUGH OVERHEAD AS H85
TEMPERATURES FALL TO -6 TO -7C SUPPORTING HIGHS IN THE MID 40S AND
WIND CHILLS IN THE MID 30S.

MARINE...

FRESH TO LOCALLY STRONG SOUTHEAST WINDS WILL VEER TO THE SOUTHWEST
THROUGH TODAY. A FEW GUSTS TO NEAR GALES WILL BE POSSIBLE...MAINLY
IN NEARSHORE ZONES INCLUDING LAKE SAINT CLAIR AND ERIE. SMALL CRAFT
ADVISORIES THEREFORE REMAIN IN EFFECT FOR ALL NEARSHORE ZONES.
BREEZY WESTERLY WINDS WILL PERSIST THROUGH MIDWEEK AS CONDITIONS
REMAIN RELATIVELY STATIC WITH LOW PRESSURE PARKED OVER THE GREAT
LAKES. ADDITIONAL SMALL CRAFT ADVISORIES FOR WIND WILL LIKELY BE
NEEDED ON TUESDAY AND POSSIBLY ONCE MORE ON WEDNESDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LHZ421-422-
     441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LEZ444.

&&

$$

AVIATION.....DRK
SHORT TERM...DRK
LONG TERM....JVC
MARINE.......JVC


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).




000
FXUS63 KDTX 201138
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
738 AM EDT MON APR 20 2015


.AVIATION...

LOW PRESSURE LIFTING NORTH THROUGH WESTERN MI WILL BRING GUSTY WINDS
AND RAIN SHOWERS INTO THE REGION TODAY. OUTSIDE OF AN INITIAL POP OF
WIND GUSTING TO AROUND 30 KNOTS RIGHT BEHIND THE NORTHBOUND WARM
FRONT...SW WINDS WILL GUST TO AROUND 25 KNOTS THIS MORNING BEFORE
INCREASING TO 30-35 KNOTS THIS AFTERNOON. CEILINGS WILL VARY THROUGH
THE DAY WITH THE PASSAGE OF THE WARM FRONT...INCREASING COVERAGE OF
RAIN SHOWERS...THEN A COLD FRONTAL PASSAGE LATE THIS AFTERNOON. WILL
BEGIN THE DAY WITH IFR/MVFR BEFORE IMPROVING TO VFR THIS EVENING
THROUGH THE OVERNIGHT.

FOR DTW...WIND GUSTS WITHIN THE SW FLOW OF THE WARM SECTOR WILL TOP
25 KNOTS INTO THE EVENING HOURS BEFORE RELAXING OVERNIGHT...BUT
STILL REMAINING ELEVATED AROUND 10 KNOTS DUE TO CONTINUED MIXING. A
FEW SPOTTY SHOWERS COULD OCCUR THROUGH THE EARLY PART OF THE DAY
BEFORE AN APPROACHING COLD FRONT INCREASES RAIN COVERAGE FROM ABOUT
17-21Z. THERE IS A CHANCE WE COULD SEE A FEW THUNDERSTORMS BUT
CONFIDENCE IS TOO LOW TO INCLUDE IN THE TAFS.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS AOB 5KFT THROUGH TONIGHT.

* LOW IN THUNDERSTORMS THIS AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 353 AM EDT MON APR 20 2015

SHORT TERM...TODAY AND TONIGHT

THE WELL ADVERTISED STRONG LOW PRESSURE SYSTEM HAS LIFTED INTO SW
LOWER MI AS OF 07Z THIS MORNING. IT WILL CONTINUE NORTHWARD REACHING
ONTARIO BY 00Z THIS EVENING. ALTHOUGH THE MAIN WING OF ISENTROPIC
ASCENT NORTH OF THE WARM FRONT AND COLOCATED RIBBON OF ENHANCED
MOISTURE IS NORTH OF SE MI...ELEVATED MOISTURE VALUES WILL LINGER
INTO THE EARLY AFTERNOON AS IT APPEARS THE EASTERN PORTION OF THE
CWA SHOULD RESIDE IN THE WARM SECTOR FOR SEVERAL HOURS. HOW THE
AFTERNOON WILL SHAPE UP WILL DEPEND ON A COMPACT SHORTWAVE ROTATING
AROUND THE BASE THE MID LEVEL TROUGH WHICH IS OVER THE UPPER
MISSISSIPPI VALLEY AND WILL SWING THROUGH THE OHIO VALLEY LATER
TODAY. THIS SHORTWAVE IS FORECAST TO LIFT SOMEWHERE THROUGH SE LOWER
MI OR WESTERN LAKE ERIE. THIS HAS BIG IMPLICATIONS ON THE FORECAST
DUE TO THE TIMING OF THE COLD FRONT THIS SECONDARY LOW WILL PULL
THROUGH THE AREA. CURRENTLY MODELS HAVE THE TIMING FAIRLY WELL
PEGGED DOWN TO THE 18-21Z TIMEFRAME. THIS WOULD ALLOW ENOUGH DIURNAL
HEATING TO POTENTIALLY BUILD UP A FEW HUNDRED J/KG OF CAPE AHEAD OF
THE APPROACHING COLD FRONT WITH VERY FAVORABLE LL LAPSE RATES AND
DEEP LAYER OF STRONG SW FLOW WITH SPEED SHEAR SETTING UP IN THE WARM
SECTOR. SPC HAS EXPANDED THE MARGINAL AREA TO INCLUDE A SLIVER OF
EXTREME EASTERN LOWER MI...EAST OF A LINE FROM ABOUT ADRIAN TO PORT
HURON. THERE IS CONCERN AS TO WHETHER THIS WILL ACTUALLY CONCERN AS
THE NAM/GEMREG/HRRR/ETC... SUGGEST THAT THE LL JET MAX WILL DRIFT
EASTWARD AND IGNITE THE COLD FRONT JUST SE OF MI LEAVING US WITH
ONLY RESIDUAL SHOWERS AND ISOLATED RUMBLES OF THUNDER AS THE FRONTAL
BOUNDARIES OCCLUDE AND SLIDE THROUGH THE AREA WITH THE TRIPLE POINT
STAYING SOUTH. AFTER SEVERAL MODEL RUNS TRENDING WESTWARD...THE
RECENT RUNS ARE STALLING IF NOT SHIFTING SLIGHTLY FURTHER EAST WHICH
LENDS CREDENCE THUNDERSTORM POTENTIAL DOUBTS. OVERALL THINK WE WILL
GET BRUSHED WITH SOME THUNDERSTORMS BUT THE BETTER ORGANIZED STORMS
WILL LIKELY STAY OUT OF THE AREA.

IN ADDITION TO COLD FRONTAL THUNDERSTORM POTENTIAL...WINDS WILL BE
QUITE GUSTY THROUGH THE DAY. THE DEEP MIXED LAYER WITH 900MB WINDS
MAKING A RUN AT 40 KNOTS WILL KEEP SW SFC FLOW AROUND 20KT WITH
GUSTS APPROACHING 35 KNOTS...ESPECIALLY EARLY THIS AFTERNOON EAST OF
THE FRONT.

AS THE FOR THE REST OF THE EVENING AND INTO THE OVERNIGHT...THE COLD
FRONT...OR OCCLUDED FRONT...WILL USHER IN MUCH COOLER AIR WHILE
KEEPING THE MIXED LAYER IN TACK THROUGH THE NIGHT WHICH WILL IN TURN
KEEP WINDS ELEVATED. THE ENHANCED MOISTURE PLUME WILL BE SHUNTED
EAST BUT SCATTERED SHOWERS WILL LINGER THROUGH THE OVERNIGHT AS CAA
RESULTS IN MORE FAVORABLE MID LEVEL LAPSE RATES. THE MIXING AND
CLOUD COVER WILL KEEP MIN TEMPS UP AROUND 40 FOR MOST LOCATIONS.

LONG TERM...

CLOSED UPPER LOW WILL REMAIN PARKED OVERHEAD THROUGH MIDWEEK.
EMBEDDED SHORTWAVES WILL BRING EPISODIC SHOWER ACTIVITY, THE TIMING
OF WHICH WILL REMAIN INHERENTLY ILL-DEFINED OUTSIDE OF 48 HOURS. A
COLD COLUMN AND CLOUD COVER WILL KEEP TEMPERATURES SOLIDLY BELOW
NORMAL.

LOW CENTER WILL MEANDER FROM INTERNATIONAL FALLS THIS AFTN TO THE
STRAITS BY MIDDAY TUESDAY. APRIL INSOLATION AND VERY COLD H5 TEMPS
WITHIN THE MID-LEVEL COLD POOL OF -30C WILL RESULT IN A DEEP MIXED
LAYER PERHAPS APPROACHING 600MB. ROBUST WSW WIND FIELD WITHIN THIS
VERY WELL-MIXED ENVIRONMENT WILL SET THE STAGE FOR WIDESPREAD WIND
GUSTS IN EXCESS OF 30 KNOTS FOR THE BALANCE OF TUESDAY AFTERNOON.
THE TRADE-OFF OF THE DEEP MIXING WILL BE TEMPERATURES REACHING THE
LOW 50S IN SPITE OF SUB-ZERO 850MB TEMPERATURES. SUFFICIENT MID-
LEVEL MOISTURE RESIDING IN THE 800-600MB LAYER WILL RESULT IN, AT
MINIMUM, WIDESPREAD AFTERNOON CLOUDS. MODELS ALSO POINT TO MID-
MORNING SHOWER GENERATION AS WELL, GIVEN A FEW HUNDRED J/KG CAPE
AVAILABLE FOR SURFACE BASED PARCELS. PASSING ELONGATED H4 PV ANOMALY
WILL PROVIDE BROAD SCALE ASCENT WHILE INLAND TROUGHING HELPS IS
NOTED TO HELP FOCUS ACTIVITY ALONG/NORTH OF M59. CLASSIC INVERTED V
THERMODYNAMIC PROFILE WILL ALLOW SHOWERS TO POTENTIALLY PRODUCE WIND
GUSTS OF 45 KTS.

LOSS OF DIURNAL HEATING WILL MEAN AN END TO SHOWERS TUESDAY EVENING.
THE GRADIENT WILL REMAIN ELEVATED AS BROAD LOW PRESSURE REMAINS
CENTERED OVER THE GREAT LAKES. COMBINED WITH CLOUDS, LOW
TEMPERATURES WILL BE COLD - BUT NOT AS COLD AS THEY COULD BE GIVEN
THE AIRMASS. PREFER NAM12 DEPICTION OF 34-38F TUESDAY NIGHT.

LITTLE CHANGE IN SYNOPTIC SCALE REGIME FOR WEDNESDAY, MEANING
CONTINUED DIURNALLY DRIVEN BOUNDARY LAYER CLOUD COVER AND AFTERNOON
WIND GUSTS IN THE 25-30 KT RANGE FROM THE WEST. BETTER LOW-LEVEL
MOISTURE QUALITY WILL BE OFFSET BY LACK OF FOCUSED FORCING, BUT HAVE
TO RESPECT POTENTIAL WITH A LOW END CHC POP. THE MOST NOTEWORTHY
CHANGE BY WED WILL BE POSITION OF THE THERMAL TROUGH OVERHEAD AS H85
TEMPERATURES FALL TO -6 TO -7C SUPPORTING HIGHS IN THE MID 40S AND
WIND CHILLS IN THE MID 30S.

MARINE...

FRESH TO LOCALLY STRONG SOUTHEAST WINDS WILL VEER TO THE SOUTHWEST
THROUGH TODAY. A FEW GUSTS TO NEAR GALES WILL BE POSSIBLE...MAINLY
IN NEARSHORE ZONES INCLUDING LAKE SAINT CLAIR AND ERIE. SMALL CRAFT
ADVISORIES THEREFORE REMAIN IN EFFECT FOR ALL NEARSHORE ZONES.
BREEZY WESTERLY WINDS WILL PERSIST THROUGH MIDWEEK AS CONDITIONS
REMAIN RELATIVELY STATIC WITH LOW PRESSURE PARKED OVER THE GREAT
LAKES. ADDITIONAL SMALL CRAFT ADVISORIES FOR WIND WILL LIKELY BE
NEEDED ON TUESDAY AND POSSIBLY ONCE MORE ON WEDNESDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LHZ421-422-
     441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LEZ444.

&&

$$

AVIATION.....DRK
SHORT TERM...DRK
LONG TERM....JVC
MARINE.......JVC


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).



000
FXUS63 KMQT 201113
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
713 AM EDT MON APR 20 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT MON APR 20 2015

UPPER AIR PATTERN CONSISTS OF A ELONGATED 500 MB TROUGH WITH SEVERAL
SHORTWAVES EMBEDDED IN IT. THE SHORTWAVE OVER LOWER MICHIGAN WILL BE
SPREADING PCPN UP INTO THE CWA THIS MORNING WHILE ANOTHER SHORTWAVE
OVER THE RED RIVER VALLEY OF THE NORTH WILL PUT PCPN IN OVER THE FAR
WEST THIS MORNING. BOTH THESE SHORTWAVES WILL COMBINE OVER THE AREA
AND CAUSE SOME WIDESPREAD PCPN THIS MORNING OVER THE CWA. UPPER
TROUGH SLOWLY MOVES EAST WITH A 500 MB LOW MOVING OVER THE U.P. LATE
TONIGHT. NAM SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE OVER THE CWA THIS MORNING. THE DEEPER MOISTURE REMAIN
OVER THE AREA THROUGH TONIGHT WHILE THE Q-VECTOR CONVERGENCE WEAKENS
AND MOVES OUT BY THIS EVENING BEFORE MOVING BACK IN LATE TONIGHT
WITH THE 500 MB LOW. GFS AND ECMWF SHOW ABOUT THE SAME THING AS
WELL.

HAD TO HANG ONTO THE DRIER AIR ACROSS THE CENTRAL CWA A BIT LONGER
THIS MORNING AND CUT THE QPF AMOUNTS BECAUSE OF THIS. DID GO WITH A
COMBO OF WET BULB HEIGHTS AND WARM TEMPERATURES ALOFT TO DETERMINE
SNOW FOR THIS FORECAST AND LOOKS LIKE THE ACCUMULATING SNOW WILL BE
TONIGHT WHERE UP TO 2 INCHES COULD FALL ACROSS THE WESTERN
HIGHLANDS. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
TEMPERATURE FORECAST AND WENT WITH CATEGORICAL POPS FOR TODAY FOR
THE CWA AND THEN LIKELY POPS IN NORTHWEST LAKE EFFECT BELTS TONIGHT
AND KEPT SOME SLIGHT CHANCE POPS IN THE FAR SOUTH DUE TO THE UPPER
LOW MOVING INTO THE AREA AND WRAPAROUND PCPN IN THE AREA.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 507 AM EDT MON APR 20 2015

COLDER...WITH LITTLE BREAK IN IN THE NEAR FUTURE. THE BEST CHANCE OF
LIGHT PRECIP WILL BE ALONG THE LAKE SUPERIOR SHORELINE.

AT 12Z TUESDAY THE SFC LOW WILL HAVE SHIFTED TO JUST W OF JAMES
BAY...WITH A TROUGH/SECONDARY COLD FRONT EXTENDING OVER CENTRAL LAKE
SUPERIOR AND CENTRAL UPPER MI. 850MB TEMPS AHEAD OF THE TROUGH WILL
AVERAGE AROUND -4C...AND FALL TO AROUND -7C BY THE END OF THE DAY
BEHIND THE TROUGH. THIS WILL COINCIDE WITH THE PASSAGE OF THE LARGE
500MB LOW...CENTERED OVER THE CWA TUESDAY. THE SIZABLE TROUGH WILL
ENCOMPASS E MT THROUGH THE GULF STATES...AND BACK UP THROUGH THE NEW
ENGLAND STATES.

THE 500MB LOW WILL NOT MOVE MUCH...ONLY TO E ONTARIO BY THURSDAY
MORNING. THIS WILL BE SIMILAR TO THE SFC LOW WHICH WILL ONLY SHIFT
TO FAR W ONTARIO DURING THE SAME TIME. LOOK FOR PERSISTENT NW WINDS
AND 850MB TEMPS OF -8 TO -12C.

THE 500MB LOW WILL CONTINUE ITS E PROGRESSION THURSDAY NIGHT THROUGH
FRIDAY...MOVING ACROSS S QUEBEC. WHILE A WEAK RIDGE WILL ATTEMPT TO
BUILD OVER FAR W LAKE SUPERIOR/UPPER MI...THE TROUGH WILL STILL
REMAIN OVER THE E. WHILE THE SFC LOW INITIALLY SHIFTS TO SE QUEBEC
EARLY THURSDAY EVENING...IT LOOKS TO SHIFT BACK W DURING THE DAY
FRIDAY /PARTICULARLY OFF THE GFS SOLUTION/.

THERE LOOKS TO BE SOME DISCREPANCIES IN THE HANDLING OF THE 500MB
LOW FOR THE LATTER HALF OF THE WEEKEND BY THE 00Z MODEL RUNS. WHILE
THE ECMWF PUSHES A RIDGE OVER THE UPPER GREAT LAKES SATURDAY AND
SUNDAY...THE GFS KEEPS THE TROUGH IN PLACE. AS A RESULT...FEW
CHANGES WERE MADE TO THE ONGOING FCST FOR THE WEEKEND. TEMPS MAY
RISE AROUND 5F SUNDAY COMPARED TO SATURDAY...BUT WAS LACKING
CONFIDENCE TO DO MUCH MORE THAN THAT. THE ECMWF SOLUTION WOULD BRING
850MB TEMPS BACK TO -2C BY SATURDAY AFTERNOON WITH THAT RIDGE
BUILDING IN. HOWEVER...THE GFS IS STILL AROUND -8C.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 713 AM EDT MON APR 20 2015

KIWD...WITH RAIN OVER THE COLD LAKE WATERS AND AN UPSLOPE NW
WIND...LIFR CONDITIONS WILL LIKELY PREVAIL THRU THE MORNING HRS. THE
-SHRA WILL MIX WITH OR CHANGE TO -SHSN AROUND MID MORNING. PCPN
WILL THEN DIMINISH IN THE AFTN WITH CONDITIONS IMPROVING TO MVFR
UNDER GUSTY WNW WINDS. MIGHT EVEN SEE A PERIOD OF VFR CONDITIONS.
ANOTHER DISTURBANCE WILL BRING DETERIORATING CONDITIONS AGAIN LATE
THIS EVENING BACK TO IFR AFTER MIDNIGHT WITH SNOW.

AT KCMX...EXPECT A QUICK DROP TO LIFR DURING THE MORNING UNDER
INCREASING UPSLOPE NW WINDS...THEN ONLY GRADUAL IMPROVEMENT TO IFR
IN THE AFTN AS -SHRA CONTINUE. NW WIND WILL LIKELY GUST TO AROUND
30KT DURING THE AFTN. PCPN WILL TURN TO SNOW TONIGHT.

AT KSAW...LIFR CONDITIONS WILL CONTINUE THIS MORNING. AS WINDS BACK
TO THE NW AND THEN W IN THE AFTN AND PCPN DIMINISHES...EXPECT
IMPROVEMENT TO MVFR.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT MON APR 20 2015

AS A LOW LIFTS THROUGH THE SOO THIS AFTERNOON...WINDS WILL BACK TO
THE WEST-NORTHWEST THIS AFTERNOON. WITH THE LOW BECOMING STATIONARY
JUST TO THE SOUTHWEST OF JAMES BAY TONIGHT THROUGH
WEDNESDAY...PERSISTENT NORTHWESTERLY WINDS OF 20-30KTS ARE EXPECTED.
ALTHOUGH THE LOW WILL WEAKEN AND MOVE EAST ACROSS QUEBEC WEDNESDAY
NIGHT INTO THURSDAY...THE NORTHWEST WINDS UP TO 25KTS WILL PERSIST
AS A RIDGE MOVES INTO THE NORTHERN PLAINS. THE WINDS DIMINISH THEN
BELOW 20 KNOTS BY THURSDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...KF
AVIATION...07
MARINE...07



000
FXUS63 KMQT 201113
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
713 AM EDT MON APR 20 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT MON APR 20 2015

UPPER AIR PATTERN CONSISTS OF A ELONGATED 500 MB TROUGH WITH SEVERAL
SHORTWAVES EMBEDDED IN IT. THE SHORTWAVE OVER LOWER MICHIGAN WILL BE
SPREADING PCPN UP INTO THE CWA THIS MORNING WHILE ANOTHER SHORTWAVE
OVER THE RED RIVER VALLEY OF THE NORTH WILL PUT PCPN IN OVER THE FAR
WEST THIS MORNING. BOTH THESE SHORTWAVES WILL COMBINE OVER THE AREA
AND CAUSE SOME WIDESPREAD PCPN THIS MORNING OVER THE CWA. UPPER
TROUGH SLOWLY MOVES EAST WITH A 500 MB LOW MOVING OVER THE U.P. LATE
TONIGHT. NAM SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE OVER THE CWA THIS MORNING. THE DEEPER MOISTURE REMAIN
OVER THE AREA THROUGH TONIGHT WHILE THE Q-VECTOR CONVERGENCE WEAKENS
AND MOVES OUT BY THIS EVENING BEFORE MOVING BACK IN LATE TONIGHT
WITH THE 500 MB LOW. GFS AND ECMWF SHOW ABOUT THE SAME THING AS
WELL.

HAD TO HANG ONTO THE DRIER AIR ACROSS THE CENTRAL CWA A BIT LONGER
THIS MORNING AND CUT THE QPF AMOUNTS BECAUSE OF THIS. DID GO WITH A
COMBO OF WET BULB HEIGHTS AND WARM TEMPERATURES ALOFT TO DETERMINE
SNOW FOR THIS FORECAST AND LOOKS LIKE THE ACCUMULATING SNOW WILL BE
TONIGHT WHERE UP TO 2 INCHES COULD FALL ACROSS THE WESTERN
HIGHLANDS. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
TEMPERATURE FORECAST AND WENT WITH CATEGORICAL POPS FOR TODAY FOR
THE CWA AND THEN LIKELY POPS IN NORTHWEST LAKE EFFECT BELTS TONIGHT
AND KEPT SOME SLIGHT CHANCE POPS IN THE FAR SOUTH DUE TO THE UPPER
LOW MOVING INTO THE AREA AND WRAPAROUND PCPN IN THE AREA.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 507 AM EDT MON APR 20 2015

COLDER...WITH LITTLE BREAK IN IN THE NEAR FUTURE. THE BEST CHANCE OF
LIGHT PRECIP WILL BE ALONG THE LAKE SUPERIOR SHORELINE.

AT 12Z TUESDAY THE SFC LOW WILL HAVE SHIFTED TO JUST W OF JAMES
BAY...WITH A TROUGH/SECONDARY COLD FRONT EXTENDING OVER CENTRAL LAKE
SUPERIOR AND CENTRAL UPPER MI. 850MB TEMPS AHEAD OF THE TROUGH WILL
AVERAGE AROUND -4C...AND FALL TO AROUND -7C BY THE END OF THE DAY
BEHIND THE TROUGH. THIS WILL COINCIDE WITH THE PASSAGE OF THE LARGE
500MB LOW...CENTERED OVER THE CWA TUESDAY. THE SIZABLE TROUGH WILL
ENCOMPASS E MT THROUGH THE GULF STATES...AND BACK UP THROUGH THE NEW
ENGLAND STATES.

THE 500MB LOW WILL NOT MOVE MUCH...ONLY TO E ONTARIO BY THURSDAY
MORNING. THIS WILL BE SIMILAR TO THE SFC LOW WHICH WILL ONLY SHIFT
TO FAR W ONTARIO DURING THE SAME TIME. LOOK FOR PERSISTENT NW WINDS
AND 850MB TEMPS OF -8 TO -12C.

THE 500MB LOW WILL CONTINUE ITS E PROGRESSION THURSDAY NIGHT THROUGH
FRIDAY...MOVING ACROSS S QUEBEC. WHILE A WEAK RIDGE WILL ATTEMPT TO
BUILD OVER FAR W LAKE SUPERIOR/UPPER MI...THE TROUGH WILL STILL
REMAIN OVER THE E. WHILE THE SFC LOW INITIALLY SHIFTS TO SE QUEBEC
EARLY THURSDAY EVENING...IT LOOKS TO SHIFT BACK W DURING THE DAY
FRIDAY /PARTICULARLY OFF THE GFS SOLUTION/.

THERE LOOKS TO BE SOME DISCREPANCIES IN THE HANDLING OF THE 500MB
LOW FOR THE LATTER HALF OF THE WEEKEND BY THE 00Z MODEL RUNS. WHILE
THE ECMWF PUSHES A RIDGE OVER THE UPPER GREAT LAKES SATURDAY AND
SUNDAY...THE GFS KEEPS THE TROUGH IN PLACE. AS A RESULT...FEW
CHANGES WERE MADE TO THE ONGOING FCST FOR THE WEEKEND. TEMPS MAY
RISE AROUND 5F SUNDAY COMPARED TO SATURDAY...BUT WAS LACKING
CONFIDENCE TO DO MUCH MORE THAN THAT. THE ECMWF SOLUTION WOULD BRING
850MB TEMPS BACK TO -2C BY SATURDAY AFTERNOON WITH THAT RIDGE
BUILDING IN. HOWEVER...THE GFS IS STILL AROUND -8C.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 713 AM EDT MON APR 20 2015

KIWD...WITH RAIN OVER THE COLD LAKE WATERS AND AN UPSLOPE NW
WIND...LIFR CONDITIONS WILL LIKELY PREVAIL THRU THE MORNING HRS. THE
-SHRA WILL MIX WITH OR CHANGE TO -SHSN AROUND MID MORNING. PCPN
WILL THEN DIMINISH IN THE AFTN WITH CONDITIONS IMPROVING TO MVFR
UNDER GUSTY WNW WINDS. MIGHT EVEN SEE A PERIOD OF VFR CONDITIONS.
ANOTHER DISTURBANCE WILL BRING DETERIORATING CONDITIONS AGAIN LATE
THIS EVENING BACK TO IFR AFTER MIDNIGHT WITH SNOW.

AT KCMX...EXPECT A QUICK DROP TO LIFR DURING THE MORNING UNDER
INCREASING UPSLOPE NW WINDS...THEN ONLY GRADUAL IMPROVEMENT TO IFR
IN THE AFTN AS -SHRA CONTINUE. NW WIND WILL LIKELY GUST TO AROUND
30KT DURING THE AFTN. PCPN WILL TURN TO SNOW TONIGHT.

AT KSAW...LIFR CONDITIONS WILL CONTINUE THIS MORNING. AS WINDS BACK
TO THE NW AND THEN W IN THE AFTN AND PCPN DIMINISHES...EXPECT
IMPROVEMENT TO MVFR.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT MON APR 20 2015

AS A LOW LIFTS THROUGH THE SOO THIS AFTERNOON...WINDS WILL BACK TO
THE WEST-NORTHWEST THIS AFTERNOON. WITH THE LOW BECOMING STATIONARY
JUST TO THE SOUTHWEST OF JAMES BAY TONIGHT THROUGH
WEDNESDAY...PERSISTENT NORTHWESTERLY WINDS OF 20-30KTS ARE EXPECTED.
ALTHOUGH THE LOW WILL WEAKEN AND MOVE EAST ACROSS QUEBEC WEDNESDAY
NIGHT INTO THURSDAY...THE NORTHWEST WINDS UP TO 25KTS WILL PERSIST
AS A RIDGE MOVES INTO THE NORTHERN PLAINS. THE WINDS DIMINISH THEN
BELOW 20 KNOTS BY THURSDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...KF
AVIATION...07
MARINE...07



000
FXUS63 KMQT 201113
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
713 AM EDT MON APR 20 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT MON APR 20 2015

UPPER AIR PATTERN CONSISTS OF A ELONGATED 500 MB TROUGH WITH SEVERAL
SHORTWAVES EMBEDDED IN IT. THE SHORTWAVE OVER LOWER MICHIGAN WILL BE
SPREADING PCPN UP INTO THE CWA THIS MORNING WHILE ANOTHER SHORTWAVE
OVER THE RED RIVER VALLEY OF THE NORTH WILL PUT PCPN IN OVER THE FAR
WEST THIS MORNING. BOTH THESE SHORTWAVES WILL COMBINE OVER THE AREA
AND CAUSE SOME WIDESPREAD PCPN THIS MORNING OVER THE CWA. UPPER
TROUGH SLOWLY MOVES EAST WITH A 500 MB LOW MOVING OVER THE U.P. LATE
TONIGHT. NAM SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE OVER THE CWA THIS MORNING. THE DEEPER MOISTURE REMAIN
OVER THE AREA THROUGH TONIGHT WHILE THE Q-VECTOR CONVERGENCE WEAKENS
AND MOVES OUT BY THIS EVENING BEFORE MOVING BACK IN LATE TONIGHT
WITH THE 500 MB LOW. GFS AND ECMWF SHOW ABOUT THE SAME THING AS
WELL.

HAD TO HANG ONTO THE DRIER AIR ACROSS THE CENTRAL CWA A BIT LONGER
THIS MORNING AND CUT THE QPF AMOUNTS BECAUSE OF THIS. DID GO WITH A
COMBO OF WET BULB HEIGHTS AND WARM TEMPERATURES ALOFT TO DETERMINE
SNOW FOR THIS FORECAST AND LOOKS LIKE THE ACCUMULATING SNOW WILL BE
TONIGHT WHERE UP TO 2 INCHES COULD FALL ACROSS THE WESTERN
HIGHLANDS. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
TEMPERATURE FORECAST AND WENT WITH CATEGORICAL POPS FOR TODAY FOR
THE CWA AND THEN LIKELY POPS IN NORTHWEST LAKE EFFECT BELTS TONIGHT
AND KEPT SOME SLIGHT CHANCE POPS IN THE FAR SOUTH DUE TO THE UPPER
LOW MOVING INTO THE AREA AND WRAPAROUND PCPN IN THE AREA.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 507 AM EDT MON APR 20 2015

COLDER...WITH LITTLE BREAK IN IN THE NEAR FUTURE. THE BEST CHANCE OF
LIGHT PRECIP WILL BE ALONG THE LAKE SUPERIOR SHORELINE.

AT 12Z TUESDAY THE SFC LOW WILL HAVE SHIFTED TO JUST W OF JAMES
BAY...WITH A TROUGH/SECONDARY COLD FRONT EXTENDING OVER CENTRAL LAKE
SUPERIOR AND CENTRAL UPPER MI. 850MB TEMPS AHEAD OF THE TROUGH WILL
AVERAGE AROUND -4C...AND FALL TO AROUND -7C BY THE END OF THE DAY
BEHIND THE TROUGH. THIS WILL COINCIDE WITH THE PASSAGE OF THE LARGE
500MB LOW...CENTERED OVER THE CWA TUESDAY. THE SIZABLE TROUGH WILL
ENCOMPASS E MT THROUGH THE GULF STATES...AND BACK UP THROUGH THE NEW
ENGLAND STATES.

THE 500MB LOW WILL NOT MOVE MUCH...ONLY TO E ONTARIO BY THURSDAY
MORNING. THIS WILL BE SIMILAR TO THE SFC LOW WHICH WILL ONLY SHIFT
TO FAR W ONTARIO DURING THE SAME TIME. LOOK FOR PERSISTENT NW WINDS
AND 850MB TEMPS OF -8 TO -12C.

THE 500MB LOW WILL CONTINUE ITS E PROGRESSION THURSDAY NIGHT THROUGH
FRIDAY...MOVING ACROSS S QUEBEC. WHILE A WEAK RIDGE WILL ATTEMPT TO
BUILD OVER FAR W LAKE SUPERIOR/UPPER MI...THE TROUGH WILL STILL
REMAIN OVER THE E. WHILE THE SFC LOW INITIALLY SHIFTS TO SE QUEBEC
EARLY THURSDAY EVENING...IT LOOKS TO SHIFT BACK W DURING THE DAY
FRIDAY /PARTICULARLY OFF THE GFS SOLUTION/.

THERE LOOKS TO BE SOME DISCREPANCIES IN THE HANDLING OF THE 500MB
LOW FOR THE LATTER HALF OF THE WEEKEND BY THE 00Z MODEL RUNS. WHILE
THE ECMWF PUSHES A RIDGE OVER THE UPPER GREAT LAKES SATURDAY AND
SUNDAY...THE GFS KEEPS THE TROUGH IN PLACE. AS A RESULT...FEW
CHANGES WERE MADE TO THE ONGOING FCST FOR THE WEEKEND. TEMPS MAY
RISE AROUND 5F SUNDAY COMPARED TO SATURDAY...BUT WAS LACKING
CONFIDENCE TO DO MUCH MORE THAN THAT. THE ECMWF SOLUTION WOULD BRING
850MB TEMPS BACK TO -2C BY SATURDAY AFTERNOON WITH THAT RIDGE
BUILDING IN. HOWEVER...THE GFS IS STILL AROUND -8C.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 713 AM EDT MON APR 20 2015

KIWD...WITH RAIN OVER THE COLD LAKE WATERS AND AN UPSLOPE NW
WIND...LIFR CONDITIONS WILL LIKELY PREVAIL THRU THE MORNING HRS. THE
-SHRA WILL MIX WITH OR CHANGE TO -SHSN AROUND MID MORNING. PCPN
WILL THEN DIMINISH IN THE AFTN WITH CONDITIONS IMPROVING TO MVFR
UNDER GUSTY WNW WINDS. MIGHT EVEN SEE A PERIOD OF VFR CONDITIONS.
ANOTHER DISTURBANCE WILL BRING DETERIORATING CONDITIONS AGAIN LATE
THIS EVENING BACK TO IFR AFTER MIDNIGHT WITH SNOW.

AT KCMX...EXPECT A QUICK DROP TO LIFR DURING THE MORNING UNDER
INCREASING UPSLOPE NW WINDS...THEN ONLY GRADUAL IMPROVEMENT TO IFR
IN THE AFTN AS -SHRA CONTINUE. NW WIND WILL LIKELY GUST TO AROUND
30KT DURING THE AFTN. PCPN WILL TURN TO SNOW TONIGHT.

AT KSAW...LIFR CONDITIONS WILL CONTINUE THIS MORNING. AS WINDS BACK
TO THE NW AND THEN W IN THE AFTN AND PCPN DIMINISHES...EXPECT
IMPROVEMENT TO MVFR.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT MON APR 20 2015

AS A LOW LIFTS THROUGH THE SOO THIS AFTERNOON...WINDS WILL BACK TO
THE WEST-NORTHWEST THIS AFTERNOON. WITH THE LOW BECOMING STATIONARY
JUST TO THE SOUTHWEST OF JAMES BAY TONIGHT THROUGH
WEDNESDAY...PERSISTENT NORTHWESTERLY WINDS OF 20-30KTS ARE EXPECTED.
ALTHOUGH THE LOW WILL WEAKEN AND MOVE EAST ACROSS QUEBEC WEDNESDAY
NIGHT INTO THURSDAY...THE NORTHWEST WINDS UP TO 25KTS WILL PERSIST
AS A RIDGE MOVES INTO THE NORTHERN PLAINS. THE WINDS DIMINISH THEN
BELOW 20 KNOTS BY THURSDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...KF
AVIATION...07
MARINE...07



000
FXUS63 KMQT 201113
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
713 AM EDT MON APR 20 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT MON APR 20 2015

UPPER AIR PATTERN CONSISTS OF A ELONGATED 500 MB TROUGH WITH SEVERAL
SHORTWAVES EMBEDDED IN IT. THE SHORTWAVE OVER LOWER MICHIGAN WILL BE
SPREADING PCPN UP INTO THE CWA THIS MORNING WHILE ANOTHER SHORTWAVE
OVER THE RED RIVER VALLEY OF THE NORTH WILL PUT PCPN IN OVER THE FAR
WEST THIS MORNING. BOTH THESE SHORTWAVES WILL COMBINE OVER THE AREA
AND CAUSE SOME WIDESPREAD PCPN THIS MORNING OVER THE CWA. UPPER
TROUGH SLOWLY MOVES EAST WITH A 500 MB LOW MOVING OVER THE U.P. LATE
TONIGHT. NAM SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE OVER THE CWA THIS MORNING. THE DEEPER MOISTURE REMAIN
OVER THE AREA THROUGH TONIGHT WHILE THE Q-VECTOR CONVERGENCE WEAKENS
AND MOVES OUT BY THIS EVENING BEFORE MOVING BACK IN LATE TONIGHT
WITH THE 500 MB LOW. GFS AND ECMWF SHOW ABOUT THE SAME THING AS
WELL.

HAD TO HANG ONTO THE DRIER AIR ACROSS THE CENTRAL CWA A BIT LONGER
THIS MORNING AND CUT THE QPF AMOUNTS BECAUSE OF THIS. DID GO WITH A
COMBO OF WET BULB HEIGHTS AND WARM TEMPERATURES ALOFT TO DETERMINE
SNOW FOR THIS FORECAST AND LOOKS LIKE THE ACCUMULATING SNOW WILL BE
TONIGHT WHERE UP TO 2 INCHES COULD FALL ACROSS THE WESTERN
HIGHLANDS. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
TEMPERATURE FORECAST AND WENT WITH CATEGORICAL POPS FOR TODAY FOR
THE CWA AND THEN LIKELY POPS IN NORTHWEST LAKE EFFECT BELTS TONIGHT
AND KEPT SOME SLIGHT CHANCE POPS IN THE FAR SOUTH DUE TO THE UPPER
LOW MOVING INTO THE AREA AND WRAPAROUND PCPN IN THE AREA.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 507 AM EDT MON APR 20 2015

COLDER...WITH LITTLE BREAK IN IN THE NEAR FUTURE. THE BEST CHANCE OF
LIGHT PRECIP WILL BE ALONG THE LAKE SUPERIOR SHORELINE.

AT 12Z TUESDAY THE SFC LOW WILL HAVE SHIFTED TO JUST W OF JAMES
BAY...WITH A TROUGH/SECONDARY COLD FRONT EXTENDING OVER CENTRAL LAKE
SUPERIOR AND CENTRAL UPPER MI. 850MB TEMPS AHEAD OF THE TROUGH WILL
AVERAGE AROUND -4C...AND FALL TO AROUND -7C BY THE END OF THE DAY
BEHIND THE TROUGH. THIS WILL COINCIDE WITH THE PASSAGE OF THE LARGE
500MB LOW...CENTERED OVER THE CWA TUESDAY. THE SIZABLE TROUGH WILL
ENCOMPASS E MT THROUGH THE GULF STATES...AND BACK UP THROUGH THE NEW
ENGLAND STATES.

THE 500MB LOW WILL NOT MOVE MUCH...ONLY TO E ONTARIO BY THURSDAY
MORNING. THIS WILL BE SIMILAR TO THE SFC LOW WHICH WILL ONLY SHIFT
TO FAR W ONTARIO DURING THE SAME TIME. LOOK FOR PERSISTENT NW WINDS
AND 850MB TEMPS OF -8 TO -12C.

THE 500MB LOW WILL CONTINUE ITS E PROGRESSION THURSDAY NIGHT THROUGH
FRIDAY...MOVING ACROSS S QUEBEC. WHILE A WEAK RIDGE WILL ATTEMPT TO
BUILD OVER FAR W LAKE SUPERIOR/UPPER MI...THE TROUGH WILL STILL
REMAIN OVER THE E. WHILE THE SFC LOW INITIALLY SHIFTS TO SE QUEBEC
EARLY THURSDAY EVENING...IT LOOKS TO SHIFT BACK W DURING THE DAY
FRIDAY /PARTICULARLY OFF THE GFS SOLUTION/.

THERE LOOKS TO BE SOME DISCREPANCIES IN THE HANDLING OF THE 500MB
LOW FOR THE LATTER HALF OF THE WEEKEND BY THE 00Z MODEL RUNS. WHILE
THE ECMWF PUSHES A RIDGE OVER THE UPPER GREAT LAKES SATURDAY AND
SUNDAY...THE GFS KEEPS THE TROUGH IN PLACE. AS A RESULT...FEW
CHANGES WERE MADE TO THE ONGOING FCST FOR THE WEEKEND. TEMPS MAY
RISE AROUND 5F SUNDAY COMPARED TO SATURDAY...BUT WAS LACKING
CONFIDENCE TO DO MUCH MORE THAN THAT. THE ECMWF SOLUTION WOULD BRING
850MB TEMPS BACK TO -2C BY SATURDAY AFTERNOON WITH THAT RIDGE
BUILDING IN. HOWEVER...THE GFS IS STILL AROUND -8C.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 713 AM EDT MON APR 20 2015

KIWD...WITH RAIN OVER THE COLD LAKE WATERS AND AN UPSLOPE NW
WIND...LIFR CONDITIONS WILL LIKELY PREVAIL THRU THE MORNING HRS. THE
-SHRA WILL MIX WITH OR CHANGE TO -SHSN AROUND MID MORNING. PCPN
WILL THEN DIMINISH IN THE AFTN WITH CONDITIONS IMPROVING TO MVFR
UNDER GUSTY WNW WINDS. MIGHT EVEN SEE A PERIOD OF VFR CONDITIONS.
ANOTHER DISTURBANCE WILL BRING DETERIORATING CONDITIONS AGAIN LATE
THIS EVENING BACK TO IFR AFTER MIDNIGHT WITH SNOW.

AT KCMX...EXPECT A QUICK DROP TO LIFR DURING THE MORNING UNDER
INCREASING UPSLOPE NW WINDS...THEN ONLY GRADUAL IMPROVEMENT TO IFR
IN THE AFTN AS -SHRA CONTINUE. NW WIND WILL LIKELY GUST TO AROUND
30KT DURING THE AFTN. PCPN WILL TURN TO SNOW TONIGHT.

AT KSAW...LIFR CONDITIONS WILL CONTINUE THIS MORNING. AS WINDS BACK
TO THE NW AND THEN W IN THE AFTN AND PCPN DIMINISHES...EXPECT
IMPROVEMENT TO MVFR.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT MON APR 20 2015

AS A LOW LIFTS THROUGH THE SOO THIS AFTERNOON...WINDS WILL BACK TO
THE WEST-NORTHWEST THIS AFTERNOON. WITH THE LOW BECOMING STATIONARY
JUST TO THE SOUTHWEST OF JAMES BAY TONIGHT THROUGH
WEDNESDAY...PERSISTENT NORTHWESTERLY WINDS OF 20-30KTS ARE EXPECTED.
ALTHOUGH THE LOW WILL WEAKEN AND MOVE EAST ACROSS QUEBEC WEDNESDAY
NIGHT INTO THURSDAY...THE NORTHWEST WINDS UP TO 25KTS WILL PERSIST
AS A RIDGE MOVES INTO THE NORTHERN PLAINS. THE WINDS DIMINISH THEN
BELOW 20 KNOTS BY THURSDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...KF
AVIATION...07
MARINE...07



000
FXUS63 KAPX 201050
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
650 AM EDT MON APR 20 2015

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 245 AM EDT MON APR 20 2015

LOW PRESSURE CENTER HAS REACHED FAR SW LWR MICHIGAN EARLY THIS
MORNING. WIDESPREAD RAIN NORTH OF THE LOW CENTER HAS SPREAD ACROSS
OUR ENTIRE CWA...WITH ADDITIONAL WIDESPREAD RAIN SHOWER ACTIVITY
EXPANDING AROUND AND EAST OF THE LOW CENTER THANKS TO STRONG 700-500
MB OMEGA AND DEEP MOISTURE CONTINUING TO ADVECT INTO THE REGION.
BOTH THE LATEST NAM AND ECMWF SUGGEST THERE WILL BE A BRIEF DIMINISH
IN POP DURING LATE MORNING/EARLY AFTERNOON AS THE LOW CENTER REACHES
ERN UPR MICHIGAN. DEEP MOISTURE THEN QUICKLY WRAPS BACK INTO
MICHIGAN AS THE LOW CONTINUES NORTHWARD INTO CANADA BY LATE
AFTERNOON. WILL CERTAINLY KEEP CATEGORICAL POPS IN PLACE THRU EARLY
MORNING...WITH ONLY A MINOR DIMINISH IN POPS TO LIKELY ACROSS OUR
SRN CWA THRU THE DAY. ALL THUNDER CHANCES WILL STAY WELL SOUTH OF
MICHIGAN ALONG AND AHEAD OF THE ASSOCIATED WARM FRONT. TEMPS WILL BE
NOTICEABLY COOLER TODAY...WITH HIGH TEMPS RANGING FROM THE MID 40S
IN ERN UPR MICHIGAN TO THE UPPER 50S IN NE LWR MICHIGAN.

SRN EDGE OF WRAP AROUND MOISTURE WILL ALSO LIFT NORTHWARD AS THE
SURFACE LOW DEPARTS DEEP INTO CANADA TONIGHT. HIGHEST POPS (LIKELY)
WILL RESIDE ACROSS THE NRN TWO-THIRDS OF OUR CWA DURING THE EVENING
WHERE LIFT AND WRAP-AROUND MOISTURE WILL LINGER THE LONGEST. ALL
POPS WILL DIMINISH TO CHANCE OVERNIGHT. COLD AIR WRAPPING AROUND THE
DEPARTING LOW WILL DROP 850 MB TEMPS TO AROUND -3 TO -4 C TONIGHT.
WHILE THIS WILL NOT BE SUFFICIENTLY COLD (YET) TO ACTIVATE THE LAKES
TO PROVIDE LAKE ENHANCEMENT TO ONGOING SYNOPTIC PRECIP...BUT IT WILL
BE COLD ENOUGH TO BEGIN TO MIX SOME SNOW IN WITH THE ONGOING RAIN
EVENT DURING THE OVERNIGHT HOURS. EXPECT NO SNOW ACCUMULATION AS
SURFACE TEMPS BOTTOM OUT AT OR A FEW DEGREES ABOVE FREEZING.

&&

.SHORT TERM...(TUESDAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 245 AM EDT MON APR 20 2015

HIGH IMPACT WEATHER POTENTIAL: NOTHING SIGNIFICANT.

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: UNFORTUNATELY...NOW MUCH
TALKED ABOUT CHANGES TO A COOLER WEATHER REGIME ALREADY UNFOLDING AT
THIS EARLY HOUR...WITH ROBUST WEST NOAM RIDGE AMPLIFICATION AND
STRONG SHORTWAVE DIVING ON ITS FRONT SIDE INTO THE NORTHERN PLAINS.
THIS LATTER FEATURE WILL HELP CARVE OUT DEVELOPMENT OF ONE RATHER
IMPRESSIVE UPPER LEVEL LOW ACROSS THE FAR NORTHERN LAKES THROUGH THE
MIDDLE OF THE WEEK...WITH THE FORMER HELPING NEGATE ANY REAL KICKER
SYSTEM TO HELP BOOT THIS SYSTEM OUT. THIS SPELLS A RATHER PROLONGED
PERIOD OF COOL AND DAMP WEATHER...WITH SEVERAL OPPORTUNITIES TO SEE
A LEAST A LITTLE BIT OF SNOW BY THE TIME THIS WORK WEEK WRAPS UP
(QUELL THE EXCITEMENT :)).

PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE TRENDS
AND ADDRESSING PERIODIC PRECIP CHANCES AND TYPE.

DETAILS: CENTER OF UPPER LEVEL COLD CORE GYRE EXPECTED TO SLOWLY
MAKE ITS WAY EAST ACROSS LAKE SUPERIOR TO START THE SHORT TERM
PERIOD (TUESDAY)...ESSENTIALLY STALLING OUT JUST TO OUR NORTH RIGHT
THROUGH WEDNESDAY NIGHT. WHILE AT NO TIMES DOES FORCING SEEM
GREAT...SPOKES OF SUPPORT ROTATING AROUND PARENT SYSTEM COMBINING
WITH DEEP CYCLONIC MOISTURE RICH FLOW AND STEEP LOW/MID LEVEL LAPSE
RATES (H5 TEMPS STILL SLATED TO FLIRT WITH -30C) WILL DEFINITELY
SUPPORT THE THREAT FOR SHOWERS TUESDAY THROUGH WEDNESDAY NIGHT.
GIVEN LACK OF ANY DEEP LAYER TRIGGER...WOULD EXPECT GREATEST SHOWER
COVERAGE TO OCCUR DURING THE LATE MORNING/AFTERNOON HOURS WHEN LOW
LEVEL LAPSE RATES ARE MAXIMIZED. STILL HINTS OVER-RIDING AIRMASS MAY
BECOME JUST COLD ENOUGH TO ENTICE AT LEAST SOME MINOR LAKE
CONTRIBUTION LATE TUESDAY NIGHT INTO WEDNESDAY NIGHT. REAL MARGINAL
DELTA T/S (JUST FLIRTING WITH 13C) SHOULD NEGATE ANY SIGNIFICANT
RESPONSE...ALTHOUGH GOTTA ADMIT SUCH PERSISTENT WEST FLOW UP INTO
THE HIGHLANDS DOES RAISE AN EYEBROW OR TWO. INCREASINGLY COLD OFF
THE DECK THERMAL PROFILES AND STEEP LAPSE RATES DEFINITELY SUPPORTS
SNOW AND GRAUPEL MIXING IN WITH THE SHOWERS DURING THE DAYTIME HOURS
TUESDAY AND WEDNESDAY...WITH THE REAL POSSIBILITY ANY HEAVIER
SHOWERS WILL FALL AS MAINLY SNOW. OVERNIGHT PROFILES CONTINUE TO
SUPPORT MORE OF AN ALL SNOW ENVIRONMENT AS SURFACE BASED MELTING
LAYER IS NEARLY/COMPLETELY LOST. NOT EXPECTING ANY SIGNIFICANT
ACCUMULATIONS...ALTHOUGH WOULD NOT BE SURPRISED FOR THE GROUND TO
TURN WHITE BY WEDNESDAY MORNING (AN INCH OR SO)...ESPECIALLY WHERE
PERSISTENT UPSLOPE FLOW IS REALIZED INTO NORTHWEST LOWER.

AFTER THIS PAST WEEKS PLEASANT WEATHER...JUST GONNA FEEL DOWNRIGHT
CHILLY THROUGH MIDWEEK...WITH HIGHS BACK DOWN INTO THE UPPER 30S/40S
(COLDEST WEDNESDAY) AND OVERNIGHT LOWS A GOOD 10 OR SO DEGREES
COLDER. GUSTY WINDS AND DAMP CONDITIONS WILL ONLY ADD CONSIDERABLE
MORE CHILL. SOUNDS FUN...DOESN`T IT?

&&

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 245 AM EDT MON APR 20 2015

STILL SOME DISCREPANCIES
REGARDING JUST HOW LONG THIS SYSTEM LINGERS INTO THE END OF THE
WEEK...WITH THE GFS/GEFS/GEM NOTABLY SLOWER MOVING IT OUT THAN
RECENT ECMWF/UKMET RUNS. GIVEN UNCERTAINTIES...WILL SIMPLY RIDE WITH
INHERITED FORECAST...FEATURING SOME LINGERING LIGHT RAIN/SNOW
SHOWERS (AT LEAST FOR PARTS OF THE AREA) RIGHT THROUGH
FRIDAY...GIVING WAY TO A DRY WEEKEND. NO MATTER HOW FAST THIS SYSTEM
EXITS...AIRMASS RECOVERY WILL BE A SLOW ONE...SUGGESTING
TEMPERATURES REMAINING BELOW NORMAL RIGHT THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY)
ISSUED AT 650 AM EDT MON APR 20 2015

IFR/MVFR CONDITIONS ARE EXPECTED AT ALL NRN LWR MICHIGAN TAF
SITES THRU 12Z TUESDAY AS RAIN SHOWERS CONTINUE TO IMPACT THE
REGION. RAIN SHOWERS WILL BECOME SCATTERED AFTER 00Z TUESDAY. WINDS
GUSTING TO 20 KTS WILL SHIFT TO THE W/SW THIS MORNING AS THE
SURFACE LOW LIFTS NORTHWARD THRU NRN LWR MICHIGAN.

&&

.MARINE...
ISSUED AT 245 AM EDT MON APR 20 2015

SCA CRITERIA WILL CONTINUE TO BE MET ACROSS MOST OF OUR NEARSHORE
AREAS THRU THIS AFTERNOON AS DEEP LOW PRESSURE LIFTS NORTHWARD
THRU MICHIGAN. EAST WINDS WILL SHIFT TO THE SW BY AROUND MIDDAY AS
THE SURFACE LOW BEGINS TO PULL NORTH OF MICHIGAN...SHIFTING THE
FOCUS OF THE STRONGEST WINDS AND BIGGEST WAVES FROM THE LAKE
HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
     LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LMZ341-
     342-344>346.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LSZ321-
     322.

&&

$$

NEAR TERM...MLR
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...MLR
MARINE...MLR



000
FXUS63 KAPX 201050
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
650 AM EDT MON APR 20 2015

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 245 AM EDT MON APR 20 2015

LOW PRESSURE CENTER HAS REACHED FAR SW LWR MICHIGAN EARLY THIS
MORNING. WIDESPREAD RAIN NORTH OF THE LOW CENTER HAS SPREAD ACROSS
OUR ENTIRE CWA...WITH ADDITIONAL WIDESPREAD RAIN SHOWER ACTIVITY
EXPANDING AROUND AND EAST OF THE LOW CENTER THANKS TO STRONG 700-500
MB OMEGA AND DEEP MOISTURE CONTINUING TO ADVECT INTO THE REGION.
BOTH THE LATEST NAM AND ECMWF SUGGEST THERE WILL BE A BRIEF DIMINISH
IN POP DURING LATE MORNING/EARLY AFTERNOON AS THE LOW CENTER REACHES
ERN UPR MICHIGAN. DEEP MOISTURE THEN QUICKLY WRAPS BACK INTO
MICHIGAN AS THE LOW CONTINUES NORTHWARD INTO CANADA BY LATE
AFTERNOON. WILL CERTAINLY KEEP CATEGORICAL POPS IN PLACE THRU EARLY
MORNING...WITH ONLY A MINOR DIMINISH IN POPS TO LIKELY ACROSS OUR
SRN CWA THRU THE DAY. ALL THUNDER CHANCES WILL STAY WELL SOUTH OF
MICHIGAN ALONG AND AHEAD OF THE ASSOCIATED WARM FRONT. TEMPS WILL BE
NOTICEABLY COOLER TODAY...WITH HIGH TEMPS RANGING FROM THE MID 40S
IN ERN UPR MICHIGAN TO THE UPPER 50S IN NE LWR MICHIGAN.

SRN EDGE OF WRAP AROUND MOISTURE WILL ALSO LIFT NORTHWARD AS THE
SURFACE LOW DEPARTS DEEP INTO CANADA TONIGHT. HIGHEST POPS (LIKELY)
WILL RESIDE ACROSS THE NRN TWO-THIRDS OF OUR CWA DURING THE EVENING
WHERE LIFT AND WRAP-AROUND MOISTURE WILL LINGER THE LONGEST. ALL
POPS WILL DIMINISH TO CHANCE OVERNIGHT. COLD AIR WRAPPING AROUND THE
DEPARTING LOW WILL DROP 850 MB TEMPS TO AROUND -3 TO -4 C TONIGHT.
WHILE THIS WILL NOT BE SUFFICIENTLY COLD (YET) TO ACTIVATE THE LAKES
TO PROVIDE LAKE ENHANCEMENT TO ONGOING SYNOPTIC PRECIP...BUT IT WILL
BE COLD ENOUGH TO BEGIN TO MIX SOME SNOW IN WITH THE ONGOING RAIN
EVENT DURING THE OVERNIGHT HOURS. EXPECT NO SNOW ACCUMULATION AS
SURFACE TEMPS BOTTOM OUT AT OR A FEW DEGREES ABOVE FREEZING.

&&

.SHORT TERM...(TUESDAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 245 AM EDT MON APR 20 2015

HIGH IMPACT WEATHER POTENTIAL: NOTHING SIGNIFICANT.

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: UNFORTUNATELY...NOW MUCH
TALKED ABOUT CHANGES TO A COOLER WEATHER REGIME ALREADY UNFOLDING AT
THIS EARLY HOUR...WITH ROBUST WEST NOAM RIDGE AMPLIFICATION AND
STRONG SHORTWAVE DIVING ON ITS FRONT SIDE INTO THE NORTHERN PLAINS.
THIS LATTER FEATURE WILL HELP CARVE OUT DEVELOPMENT OF ONE RATHER
IMPRESSIVE UPPER LEVEL LOW ACROSS THE FAR NORTHERN LAKES THROUGH THE
MIDDLE OF THE WEEK...WITH THE FORMER HELPING NEGATE ANY REAL KICKER
SYSTEM TO HELP BOOT THIS SYSTEM OUT. THIS SPELLS A RATHER PROLONGED
PERIOD OF COOL AND DAMP WEATHER...WITH SEVERAL OPPORTUNITIES TO SEE
A LEAST A LITTLE BIT OF SNOW BY THE TIME THIS WORK WEEK WRAPS UP
(QUELL THE EXCITEMENT :)).

PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE TRENDS
AND ADDRESSING PERIODIC PRECIP CHANCES AND TYPE.

DETAILS: CENTER OF UPPER LEVEL COLD CORE GYRE EXPECTED TO SLOWLY
MAKE ITS WAY EAST ACROSS LAKE SUPERIOR TO START THE SHORT TERM
PERIOD (TUESDAY)...ESSENTIALLY STALLING OUT JUST TO OUR NORTH RIGHT
THROUGH WEDNESDAY NIGHT. WHILE AT NO TIMES DOES FORCING SEEM
GREAT...SPOKES OF SUPPORT ROTATING AROUND PARENT SYSTEM COMBINING
WITH DEEP CYCLONIC MOISTURE RICH FLOW AND STEEP LOW/MID LEVEL LAPSE
RATES (H5 TEMPS STILL SLATED TO FLIRT WITH -30C) WILL DEFINITELY
SUPPORT THE THREAT FOR SHOWERS TUESDAY THROUGH WEDNESDAY NIGHT.
GIVEN LACK OF ANY DEEP LAYER TRIGGER...WOULD EXPECT GREATEST SHOWER
COVERAGE TO OCCUR DURING THE LATE MORNING/AFTERNOON HOURS WHEN LOW
LEVEL LAPSE RATES ARE MAXIMIZED. STILL HINTS OVER-RIDING AIRMASS MAY
BECOME JUST COLD ENOUGH TO ENTICE AT LEAST SOME MINOR LAKE
CONTRIBUTION LATE TUESDAY NIGHT INTO WEDNESDAY NIGHT. REAL MARGINAL
DELTA T/S (JUST FLIRTING WITH 13C) SHOULD NEGATE ANY SIGNIFICANT
RESPONSE...ALTHOUGH GOTTA ADMIT SUCH PERSISTENT WEST FLOW UP INTO
THE HIGHLANDS DOES RAISE AN EYEBROW OR TWO. INCREASINGLY COLD OFF
THE DECK THERMAL PROFILES AND STEEP LAPSE RATES DEFINITELY SUPPORTS
SNOW AND GRAUPEL MIXING IN WITH THE SHOWERS DURING THE DAYTIME HOURS
TUESDAY AND WEDNESDAY...WITH THE REAL POSSIBILITY ANY HEAVIER
SHOWERS WILL FALL AS MAINLY SNOW. OVERNIGHT PROFILES CONTINUE TO
SUPPORT MORE OF AN ALL SNOW ENVIRONMENT AS SURFACE BASED MELTING
LAYER IS NEARLY/COMPLETELY LOST. NOT EXPECTING ANY SIGNIFICANT
ACCUMULATIONS...ALTHOUGH WOULD NOT BE SURPRISED FOR THE GROUND TO
TURN WHITE BY WEDNESDAY MORNING (AN INCH OR SO)...ESPECIALLY WHERE
PERSISTENT UPSLOPE FLOW IS REALIZED INTO NORTHWEST LOWER.

AFTER THIS PAST WEEKS PLEASANT WEATHER...JUST GONNA FEEL DOWNRIGHT
CHILLY THROUGH MIDWEEK...WITH HIGHS BACK DOWN INTO THE UPPER 30S/40S
(COLDEST WEDNESDAY) AND OVERNIGHT LOWS A GOOD 10 OR SO DEGREES
COLDER. GUSTY WINDS AND DAMP CONDITIONS WILL ONLY ADD CONSIDERABLE
MORE CHILL. SOUNDS FUN...DOESN`T IT?

&&

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 245 AM EDT MON APR 20 2015

STILL SOME DISCREPANCIES
REGARDING JUST HOW LONG THIS SYSTEM LINGERS INTO THE END OF THE
WEEK...WITH THE GFS/GEFS/GEM NOTABLY SLOWER MOVING IT OUT THAN
RECENT ECMWF/UKMET RUNS. GIVEN UNCERTAINTIES...WILL SIMPLY RIDE WITH
INHERITED FORECAST...FEATURING SOME LINGERING LIGHT RAIN/SNOW
SHOWERS (AT LEAST FOR PARTS OF THE AREA) RIGHT THROUGH
FRIDAY...GIVING WAY TO A DRY WEEKEND. NO MATTER HOW FAST THIS SYSTEM
EXITS...AIRMASS RECOVERY WILL BE A SLOW ONE...SUGGESTING
TEMPERATURES REMAINING BELOW NORMAL RIGHT THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY)
ISSUED AT 650 AM EDT MON APR 20 2015

IFR/MVFR CONDITIONS ARE EXPECTED AT ALL NRN LWR MICHIGAN TAF
SITES THRU 12Z TUESDAY AS RAIN SHOWERS CONTINUE TO IMPACT THE
REGION. RAIN SHOWERS WILL BECOME SCATTERED AFTER 00Z TUESDAY. WINDS
GUSTING TO 20 KTS WILL SHIFT TO THE W/SW THIS MORNING AS THE
SURFACE LOW LIFTS NORTHWARD THRU NRN LWR MICHIGAN.

&&

.MARINE...
ISSUED AT 245 AM EDT MON APR 20 2015

SCA CRITERIA WILL CONTINUE TO BE MET ACROSS MOST OF OUR NEARSHORE
AREAS THRU THIS AFTERNOON AS DEEP LOW PRESSURE LIFTS NORTHWARD
THRU MICHIGAN. EAST WINDS WILL SHIFT TO THE SW BY AROUND MIDDAY AS
THE SURFACE LOW BEGINS TO PULL NORTH OF MICHIGAN...SHIFTING THE
FOCUS OF THE STRONGEST WINDS AND BIGGEST WAVES FROM THE LAKE
HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
     LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LMZ341-
     342-344>346.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LSZ321-
     322.

&&

$$

NEAR TERM...MLR
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...MLR
MARINE...MLR




000
FXUS63 KAPX 201050
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
650 AM EDT MON APR 20 2015

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 245 AM EDT MON APR 20 2015

LOW PRESSURE CENTER HAS REACHED FAR SW LWR MICHIGAN EARLY THIS
MORNING. WIDESPREAD RAIN NORTH OF THE LOW CENTER HAS SPREAD ACROSS
OUR ENTIRE CWA...WITH ADDITIONAL WIDESPREAD RAIN SHOWER ACTIVITY
EXPANDING AROUND AND EAST OF THE LOW CENTER THANKS TO STRONG 700-500
MB OMEGA AND DEEP MOISTURE CONTINUING TO ADVECT INTO THE REGION.
BOTH THE LATEST NAM AND ECMWF SUGGEST THERE WILL BE A BRIEF DIMINISH
IN POP DURING LATE MORNING/EARLY AFTERNOON AS THE LOW CENTER REACHES
ERN UPR MICHIGAN. DEEP MOISTURE THEN QUICKLY WRAPS BACK INTO
MICHIGAN AS THE LOW CONTINUES NORTHWARD INTO CANADA BY LATE
AFTERNOON. WILL CERTAINLY KEEP CATEGORICAL POPS IN PLACE THRU EARLY
MORNING...WITH ONLY A MINOR DIMINISH IN POPS TO LIKELY ACROSS OUR
SRN CWA THRU THE DAY. ALL THUNDER CHANCES WILL STAY WELL SOUTH OF
MICHIGAN ALONG AND AHEAD OF THE ASSOCIATED WARM FRONT. TEMPS WILL BE
NOTICEABLY COOLER TODAY...WITH HIGH TEMPS RANGING FROM THE MID 40S
IN ERN UPR MICHIGAN TO THE UPPER 50S IN NE LWR MICHIGAN.

SRN EDGE OF WRAP AROUND MOISTURE WILL ALSO LIFT NORTHWARD AS THE
SURFACE LOW DEPARTS DEEP INTO CANADA TONIGHT. HIGHEST POPS (LIKELY)
WILL RESIDE ACROSS THE NRN TWO-THIRDS OF OUR CWA DURING THE EVENING
WHERE LIFT AND WRAP-AROUND MOISTURE WILL LINGER THE LONGEST. ALL
POPS WILL DIMINISH TO CHANCE OVERNIGHT. COLD AIR WRAPPING AROUND THE
DEPARTING LOW WILL DROP 850 MB TEMPS TO AROUND -3 TO -4 C TONIGHT.
WHILE THIS WILL NOT BE SUFFICIENTLY COLD (YET) TO ACTIVATE THE LAKES
TO PROVIDE LAKE ENHANCEMENT TO ONGOING SYNOPTIC PRECIP...BUT IT WILL
BE COLD ENOUGH TO BEGIN TO MIX SOME SNOW IN WITH THE ONGOING RAIN
EVENT DURING THE OVERNIGHT HOURS. EXPECT NO SNOW ACCUMULATION AS
SURFACE TEMPS BOTTOM OUT AT OR A FEW DEGREES ABOVE FREEZING.

&&

.SHORT TERM...(TUESDAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 245 AM EDT MON APR 20 2015

HIGH IMPACT WEATHER POTENTIAL: NOTHING SIGNIFICANT.

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: UNFORTUNATELY...NOW MUCH
TALKED ABOUT CHANGES TO A COOLER WEATHER REGIME ALREADY UNFOLDING AT
THIS EARLY HOUR...WITH ROBUST WEST NOAM RIDGE AMPLIFICATION AND
STRONG SHORTWAVE DIVING ON ITS FRONT SIDE INTO THE NORTHERN PLAINS.
THIS LATTER FEATURE WILL HELP CARVE OUT DEVELOPMENT OF ONE RATHER
IMPRESSIVE UPPER LEVEL LOW ACROSS THE FAR NORTHERN LAKES THROUGH THE
MIDDLE OF THE WEEK...WITH THE FORMER HELPING NEGATE ANY REAL KICKER
SYSTEM TO HELP BOOT THIS SYSTEM OUT. THIS SPELLS A RATHER PROLONGED
PERIOD OF COOL AND DAMP WEATHER...WITH SEVERAL OPPORTUNITIES TO SEE
A LEAST A LITTLE BIT OF SNOW BY THE TIME THIS WORK WEEK WRAPS UP
(QUELL THE EXCITEMENT :)).

PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE TRENDS
AND ADDRESSING PERIODIC PRECIP CHANCES AND TYPE.

DETAILS: CENTER OF UPPER LEVEL COLD CORE GYRE EXPECTED TO SLOWLY
MAKE ITS WAY EAST ACROSS LAKE SUPERIOR TO START THE SHORT TERM
PERIOD (TUESDAY)...ESSENTIALLY STALLING OUT JUST TO OUR NORTH RIGHT
THROUGH WEDNESDAY NIGHT. WHILE AT NO TIMES DOES FORCING SEEM
GREAT...SPOKES OF SUPPORT ROTATING AROUND PARENT SYSTEM COMBINING
WITH DEEP CYCLONIC MOISTURE RICH FLOW AND STEEP LOW/MID LEVEL LAPSE
RATES (H5 TEMPS STILL SLATED TO FLIRT WITH -30C) WILL DEFINITELY
SUPPORT THE THREAT FOR SHOWERS TUESDAY THROUGH WEDNESDAY NIGHT.
GIVEN LACK OF ANY DEEP LAYER TRIGGER...WOULD EXPECT GREATEST SHOWER
COVERAGE TO OCCUR DURING THE LATE MORNING/AFTERNOON HOURS WHEN LOW
LEVEL LAPSE RATES ARE MAXIMIZED. STILL HINTS OVER-RIDING AIRMASS MAY
BECOME JUST COLD ENOUGH TO ENTICE AT LEAST SOME MINOR LAKE
CONTRIBUTION LATE TUESDAY NIGHT INTO WEDNESDAY NIGHT. REAL MARGINAL
DELTA T/S (JUST FLIRTING WITH 13C) SHOULD NEGATE ANY SIGNIFICANT
RESPONSE...ALTHOUGH GOTTA ADMIT SUCH PERSISTENT WEST FLOW UP INTO
THE HIGHLANDS DOES RAISE AN EYEBROW OR TWO. INCREASINGLY COLD OFF
THE DECK THERMAL PROFILES AND STEEP LAPSE RATES DEFINITELY SUPPORTS
SNOW AND GRAUPEL MIXING IN WITH THE SHOWERS DURING THE DAYTIME HOURS
TUESDAY AND WEDNESDAY...WITH THE REAL POSSIBILITY ANY HEAVIER
SHOWERS WILL FALL AS MAINLY SNOW. OVERNIGHT PROFILES CONTINUE TO
SUPPORT MORE OF AN ALL SNOW ENVIRONMENT AS SURFACE BASED MELTING
LAYER IS NEARLY/COMPLETELY LOST. NOT EXPECTING ANY SIGNIFICANT
ACCUMULATIONS...ALTHOUGH WOULD NOT BE SURPRISED FOR THE GROUND TO
TURN WHITE BY WEDNESDAY MORNING (AN INCH OR SO)...ESPECIALLY WHERE
PERSISTENT UPSLOPE FLOW IS REALIZED INTO NORTHWEST LOWER.

AFTER THIS PAST WEEKS PLEASANT WEATHER...JUST GONNA FEEL DOWNRIGHT
CHILLY THROUGH MIDWEEK...WITH HIGHS BACK DOWN INTO THE UPPER 30S/40S
(COLDEST WEDNESDAY) AND OVERNIGHT LOWS A GOOD 10 OR SO DEGREES
COLDER. GUSTY WINDS AND DAMP CONDITIONS WILL ONLY ADD CONSIDERABLE
MORE CHILL. SOUNDS FUN...DOESN`T IT?

&&

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 245 AM EDT MON APR 20 2015

STILL SOME DISCREPANCIES
REGARDING JUST HOW LONG THIS SYSTEM LINGERS INTO THE END OF THE
WEEK...WITH THE GFS/GEFS/GEM NOTABLY SLOWER MOVING IT OUT THAN
RECENT ECMWF/UKMET RUNS. GIVEN UNCERTAINTIES...WILL SIMPLY RIDE WITH
INHERITED FORECAST...FEATURING SOME LINGERING LIGHT RAIN/SNOW
SHOWERS (AT LEAST FOR PARTS OF THE AREA) RIGHT THROUGH
FRIDAY...GIVING WAY TO A DRY WEEKEND. NO MATTER HOW FAST THIS SYSTEM
EXITS...AIRMASS RECOVERY WILL BE A SLOW ONE...SUGGESTING
TEMPERATURES REMAINING BELOW NORMAL RIGHT THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY)
ISSUED AT 650 AM EDT MON APR 20 2015

IFR/MVFR CONDITIONS ARE EXPECTED AT ALL NRN LWR MICHIGAN TAF
SITES THRU 12Z TUESDAY AS RAIN SHOWERS CONTINUE TO IMPACT THE
REGION. RAIN SHOWERS WILL BECOME SCATTERED AFTER 00Z TUESDAY. WINDS
GUSTING TO 20 KTS WILL SHIFT TO THE W/SW THIS MORNING AS THE
SURFACE LOW LIFTS NORTHWARD THRU NRN LWR MICHIGAN.

&&

.MARINE...
ISSUED AT 245 AM EDT MON APR 20 2015

SCA CRITERIA WILL CONTINUE TO BE MET ACROSS MOST OF OUR NEARSHORE
AREAS THRU THIS AFTERNOON AS DEEP LOW PRESSURE LIFTS NORTHWARD
THRU MICHIGAN. EAST WINDS WILL SHIFT TO THE SW BY AROUND MIDDAY AS
THE SURFACE LOW BEGINS TO PULL NORTH OF MICHIGAN...SHIFTING THE
FOCUS OF THE STRONGEST WINDS AND BIGGEST WAVES FROM THE LAKE
HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
     LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LMZ341-
     342-344>346.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LSZ321-
     322.

&&

$$

NEAR TERM...MLR
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...MLR
MARINE...MLR



000
FXUS63 KAPX 201050
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
650 AM EDT MON APR 20 2015

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 245 AM EDT MON APR 20 2015

LOW PRESSURE CENTER HAS REACHED FAR SW LWR MICHIGAN EARLY THIS
MORNING. WIDESPREAD RAIN NORTH OF THE LOW CENTER HAS SPREAD ACROSS
OUR ENTIRE CWA...WITH ADDITIONAL WIDESPREAD RAIN SHOWER ACTIVITY
EXPANDING AROUND AND EAST OF THE LOW CENTER THANKS TO STRONG 700-500
MB OMEGA AND DEEP MOISTURE CONTINUING TO ADVECT INTO THE REGION.
BOTH THE LATEST NAM AND ECMWF SUGGEST THERE WILL BE A BRIEF DIMINISH
IN POP DURING LATE MORNING/EARLY AFTERNOON AS THE LOW CENTER REACHES
ERN UPR MICHIGAN. DEEP MOISTURE THEN QUICKLY WRAPS BACK INTO
MICHIGAN AS THE LOW CONTINUES NORTHWARD INTO CANADA BY LATE
AFTERNOON. WILL CERTAINLY KEEP CATEGORICAL POPS IN PLACE THRU EARLY
MORNING...WITH ONLY A MINOR DIMINISH IN POPS TO LIKELY ACROSS OUR
SRN CWA THRU THE DAY. ALL THUNDER CHANCES WILL STAY WELL SOUTH OF
MICHIGAN ALONG AND AHEAD OF THE ASSOCIATED WARM FRONT. TEMPS WILL BE
NOTICEABLY COOLER TODAY...WITH HIGH TEMPS RANGING FROM THE MID 40S
IN ERN UPR MICHIGAN TO THE UPPER 50S IN NE LWR MICHIGAN.

SRN EDGE OF WRAP AROUND MOISTURE WILL ALSO LIFT NORTHWARD AS THE
SURFACE LOW DEPARTS DEEP INTO CANADA TONIGHT. HIGHEST POPS (LIKELY)
WILL RESIDE ACROSS THE NRN TWO-THIRDS OF OUR CWA DURING THE EVENING
WHERE LIFT AND WRAP-AROUND MOISTURE WILL LINGER THE LONGEST. ALL
POPS WILL DIMINISH TO CHANCE OVERNIGHT. COLD AIR WRAPPING AROUND THE
DEPARTING LOW WILL DROP 850 MB TEMPS TO AROUND -3 TO -4 C TONIGHT.
WHILE THIS WILL NOT BE SUFFICIENTLY COLD (YET) TO ACTIVATE THE LAKES
TO PROVIDE LAKE ENHANCEMENT TO ONGOING SYNOPTIC PRECIP...BUT IT WILL
BE COLD ENOUGH TO BEGIN TO MIX SOME SNOW IN WITH THE ONGOING RAIN
EVENT DURING THE OVERNIGHT HOURS. EXPECT NO SNOW ACCUMULATION AS
SURFACE TEMPS BOTTOM OUT AT OR A FEW DEGREES ABOVE FREEZING.

&&

.SHORT TERM...(TUESDAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 245 AM EDT MON APR 20 2015

HIGH IMPACT WEATHER POTENTIAL: NOTHING SIGNIFICANT.

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: UNFORTUNATELY...NOW MUCH
TALKED ABOUT CHANGES TO A COOLER WEATHER REGIME ALREADY UNFOLDING AT
THIS EARLY HOUR...WITH ROBUST WEST NOAM RIDGE AMPLIFICATION AND
STRONG SHORTWAVE DIVING ON ITS FRONT SIDE INTO THE NORTHERN PLAINS.
THIS LATTER FEATURE WILL HELP CARVE OUT DEVELOPMENT OF ONE RATHER
IMPRESSIVE UPPER LEVEL LOW ACROSS THE FAR NORTHERN LAKES THROUGH THE
MIDDLE OF THE WEEK...WITH THE FORMER HELPING NEGATE ANY REAL KICKER
SYSTEM TO HELP BOOT THIS SYSTEM OUT. THIS SPELLS A RATHER PROLONGED
PERIOD OF COOL AND DAMP WEATHER...WITH SEVERAL OPPORTUNITIES TO SEE
A LEAST A LITTLE BIT OF SNOW BY THE TIME THIS WORK WEEK WRAPS UP
(QUELL THE EXCITEMENT :)).

PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE TRENDS
AND ADDRESSING PERIODIC PRECIP CHANCES AND TYPE.

DETAILS: CENTER OF UPPER LEVEL COLD CORE GYRE EXPECTED TO SLOWLY
MAKE ITS WAY EAST ACROSS LAKE SUPERIOR TO START THE SHORT TERM
PERIOD (TUESDAY)...ESSENTIALLY STALLING OUT JUST TO OUR NORTH RIGHT
THROUGH WEDNESDAY NIGHT. WHILE AT NO TIMES DOES FORCING SEEM
GREAT...SPOKES OF SUPPORT ROTATING AROUND PARENT SYSTEM COMBINING
WITH DEEP CYCLONIC MOISTURE RICH FLOW AND STEEP LOW/MID LEVEL LAPSE
RATES (H5 TEMPS STILL SLATED TO FLIRT WITH -30C) WILL DEFINITELY
SUPPORT THE THREAT FOR SHOWERS TUESDAY THROUGH WEDNESDAY NIGHT.
GIVEN LACK OF ANY DEEP LAYER TRIGGER...WOULD EXPECT GREATEST SHOWER
COVERAGE TO OCCUR DURING THE LATE MORNING/AFTERNOON HOURS WHEN LOW
LEVEL LAPSE RATES ARE MAXIMIZED. STILL HINTS OVER-RIDING AIRMASS MAY
BECOME JUST COLD ENOUGH TO ENTICE AT LEAST SOME MINOR LAKE
CONTRIBUTION LATE TUESDAY NIGHT INTO WEDNESDAY NIGHT. REAL MARGINAL
DELTA T/S (JUST FLIRTING WITH 13C) SHOULD NEGATE ANY SIGNIFICANT
RESPONSE...ALTHOUGH GOTTA ADMIT SUCH PERSISTENT WEST FLOW UP INTO
THE HIGHLANDS DOES RAISE AN EYEBROW OR TWO. INCREASINGLY COLD OFF
THE DECK THERMAL PROFILES AND STEEP LAPSE RATES DEFINITELY SUPPORTS
SNOW AND GRAUPEL MIXING IN WITH THE SHOWERS DURING THE DAYTIME HOURS
TUESDAY AND WEDNESDAY...WITH THE REAL POSSIBILITY ANY HEAVIER
SHOWERS WILL FALL AS MAINLY SNOW. OVERNIGHT PROFILES CONTINUE TO
SUPPORT MORE OF AN ALL SNOW ENVIRONMENT AS SURFACE BASED MELTING
LAYER IS NEARLY/COMPLETELY LOST. NOT EXPECTING ANY SIGNIFICANT
ACCUMULATIONS...ALTHOUGH WOULD NOT BE SURPRISED FOR THE GROUND TO
TURN WHITE BY WEDNESDAY MORNING (AN INCH OR SO)...ESPECIALLY WHERE
PERSISTENT UPSLOPE FLOW IS REALIZED INTO NORTHWEST LOWER.

AFTER THIS PAST WEEKS PLEASANT WEATHER...JUST GONNA FEEL DOWNRIGHT
CHILLY THROUGH MIDWEEK...WITH HIGHS BACK DOWN INTO THE UPPER 30S/40S
(COLDEST WEDNESDAY) AND OVERNIGHT LOWS A GOOD 10 OR SO DEGREES
COLDER. GUSTY WINDS AND DAMP CONDITIONS WILL ONLY ADD CONSIDERABLE
MORE CHILL. SOUNDS FUN...DOESN`T IT?

&&

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 245 AM EDT MON APR 20 2015

STILL SOME DISCREPANCIES
REGARDING JUST HOW LONG THIS SYSTEM LINGERS INTO THE END OF THE
WEEK...WITH THE GFS/GEFS/GEM NOTABLY SLOWER MOVING IT OUT THAN
RECENT ECMWF/UKMET RUNS. GIVEN UNCERTAINTIES...WILL SIMPLY RIDE WITH
INHERITED FORECAST...FEATURING SOME LINGERING LIGHT RAIN/SNOW
SHOWERS (AT LEAST FOR PARTS OF THE AREA) RIGHT THROUGH
FRIDAY...GIVING WAY TO A DRY WEEKEND. NO MATTER HOW FAST THIS SYSTEM
EXITS...AIRMASS RECOVERY WILL BE A SLOW ONE...SUGGESTING
TEMPERATURES REMAINING BELOW NORMAL RIGHT THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY)
ISSUED AT 650 AM EDT MON APR 20 2015

IFR/MVFR CONDITIONS ARE EXPECTED AT ALL NRN LWR MICHIGAN TAF
SITES THRU 12Z TUESDAY AS RAIN SHOWERS CONTINUE TO IMPACT THE
REGION. RAIN SHOWERS WILL BECOME SCATTERED AFTER 00Z TUESDAY. WINDS
GUSTING TO 20 KTS WILL SHIFT TO THE W/SW THIS MORNING AS THE
SURFACE LOW LIFTS NORTHWARD THRU NRN LWR MICHIGAN.

&&

.MARINE...
ISSUED AT 245 AM EDT MON APR 20 2015

SCA CRITERIA WILL CONTINUE TO BE MET ACROSS MOST OF OUR NEARSHORE
AREAS THRU THIS AFTERNOON AS DEEP LOW PRESSURE LIFTS NORTHWARD
THRU MICHIGAN. EAST WINDS WILL SHIFT TO THE SW BY AROUND MIDDAY AS
THE SURFACE LOW BEGINS TO PULL NORTH OF MICHIGAN...SHIFTING THE
FOCUS OF THE STRONGEST WINDS AND BIGGEST WAVES FROM THE LAKE
HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
     LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LMZ341-
     342-344>346.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LSZ321-
     322.

&&

$$

NEAR TERM...MLR
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...MLR
MARINE...MLR




000
FXUS63 KMQT 200909
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
509 AM EDT MON APR 20 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT MON APR 20 2015

UPPER AIR PATTERN CONSISTS OF A ELONGATED 500 MB TROUGH WITH SEVERAL
SHORTWAVES EMBEDDED IN IT. THE SHORTWAVE OVER LOWER MICHIGAN WILL BE
SPREADING PCPN UP INTO THE CWA THIS MORNING WHILE ANOTHER SHORTWAVE
OVER THE RED RIVER VALLEY OF THE NORTH WILL PUT PCPN IN OVER THE FAR
WEST THIS MORNING. BOTH THESE SHORTWAVES WILL COMBINE OVER THE AREA
AND CAUSE SOME WIDESPREAD PCPN THIS MORNING OVER THE CWA. UPPER
TROUGH SLOWLY MOVES EAST WITH A 500 MB LOW MOVING OVER THE U.P. LATE
TONIGHT. NAM SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE OVER THE CWA THIS MORNING. THE DEEPER MOISTURE REMAIN
OVER THE AREA THROUGH TONIGHT WHILE THE Q-VECTOR CONVERGENCE WEAKENS
AND MOVES OUT BY THIS EVENING BEFORE MOVING BACK IN LATE TONIGHT
WITH THE 500 MB LOW. GFS AND ECMWF SHOW ABOUT THE SAME THING AS
WELL.

HAD TO HANG ONTO THE DRIER AIR ACROSS THE CENTRAL CWA A BIT LONGER
THIS MORNING AND CUT THE QPF AMOUNTS BECAUSE OF THIS. DID GO WITH A
COMBO OF WET BULB HEIGHTS AND WARM TEMPERATURES ALOFT TO DETERMINE
SNOW FOR THIS FORECAST AND LOOKS LIKE THE ACCUMULATING SNOW WILL BE
TONIGHT WHERE UP TO 2 INCHES COULD FALL ACROSS THE WESTERN
HIGHLANDS. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
TEMPERATURE FORECAST AND WENT WITH CATEGORICAL POPS FOR TODAY FOR
THE CWA AND THEN LIKELY POPS IN NORTHWEST LAKE EFFECT BELTS TONIGHT
AND KEPT SOME SLIGHT CHANCE POPS IN THE FAR SOUTH DUE TO THE UPPER
LOW MOVING INTO THE AREA AND WRAPAROUND PCPN IN THE AREA.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 507 AM EDT MON APR 20 2015

COLDER...WITH LITTLE BREAK IN IN THE NEAR FUTURE. THE BEST CHANCE OF
LIGHT PRECIP WILL BE ALONG THE LAKE SUPERIOR SHORELINE.

AT 12Z TUESDAY THE SFC LOW WILL HAVE SHIFTED TO JUST W OF JAMES
BAY...WITH A TROUGH/SECONDARY COLD FRONT EXTENDING OVER CENTRAL LAKE
SUPERIOR AND CENTRAL UPPER MI. 850MB TEMPS AHEAD OF THE TROUGH WILL
AVERAGE AROUND -4C...AND FALL TO AROUND -7C BY THE END OF THE DAY
BEHIND THE TROUGH. THIS WILL COINCIDE WITH THE PASSAGE OF THE LARGE
500MB LOW...CENTERED OVER THE CWA TUESDAY. THE SIZABLE TROUGH WILL
ENCOMPASS E MT THROUGH THE GULF STATES...AND BACK UP THROUGH THE NEW
ENGLAND STATES.

THE 500MB LOW WILL NOT MOVE MUCH...ONLY TO E ONTARIO BY THURSDAY
MORNING. THIS WILL BE SIMILAR TO THE SFC LOW WHICH WILL ONLY SHIFT
TO FAR W ONTARIO DURING THE SAME TIME. LOOK FOR PERSISTENT NW WINDS
AND 850MB TEMPS OF -8 TO -12C.

THE 500MB LOW WILL CONTINUE ITS E PROGRESSION THURSDAY NIGHT THROUGH
FRIDAY...MOVING ACROSS S QUEBEC. WHILE A WEAK RIDGE WILL ATTEMPT TO
BUILD OVER FAR W LAKE SUPERIOR/UPPER MI...THE TROUGH WILL STILL
REMAIN OVER THE E. WHILE THE SFC LOW INITIALLY SHIFTS TO SE QUEBEC
EARLY THURSDAY EVENING...IT LOOKS TO SHIFT BACK W DURING THE DAY
FRIDAY /PARTICULARLY OFF THE GFS SOLUTION/.

THERE LOOKS TO BE SOME DISCREPANCIES IN THE HANDLING OF THE 500MB
LOW FOR THE LATTER HALF OF THE WEEKEND BY THE 00Z MODEL RUNS. WHILE
THE ECMWF PUSHES A RIDGE OVER THE UPPER GREAT LAKES SATURDAY AND
SUNDAY...THE GFS KEEPS THE TROUGH IN PLACE. AS A RESULT...FEW
CHANGES WERE MADE TO THE ONGOING FCST FOR THE WEEKEND. TEMPS MAY
RISE AROUND 5F SUNDAY COMPARED TO SATURDAY...BUT WAS LACKING
CONFIDENCE TO DO MUCH MORE THAN THAT. THE ECMWF SOLUTION WOULD BRING
850MB TEMPS BACK TO -2C BY SATURDAY AFTERNOON WITH THAT RIDGE
BUILDING IN. HOWEVER...THE GFS IS STILL AROUND -8C.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 106 AM EDT MON APR 20 2015

LOW PRES OVER SW MI WILL LIFT N TODAY WHILE A LOW PRES TROF MOVES E
AND MERGES WITH THE LOW. THESE 2 FEATURES WILL SPREAD SHRA ACROSS
THE AREA OVERNIGHT...BRINGING DETERIORATING CONDITIONS.

SFC TROF HAS ALREADY PASSED KIWD. WITH RAIN OVER THE COLD LAKE
WATERS AND AN UPSLOPE NW WIND...LIFR CONDITIONS WILL LIKELY PREVAIL
THRU THE MORNING HRS. THE -SHRA WILL MIX WITH OR CHANGE TO -SHSN
AROUND MID MORNING. PCPN WILL THEN DIMINISH IN THE AFTN WITH
CONDITIONS IMPROVING TO MVFR UNDER GUSTY WNW WINDS. MIGHT EVEN SEE A
PERIOD OF VFR CONDITIONS. ANOTHER DISTURBANCE MAY BRING
DETERIORATING CONDITIONS AGAIN LATE THIS EVENING.

AT KCMX...WITH MAIN AREA OF PCPN AND SFC TROF NOT ARRIVING UNTIL
AROUND DAYBREAK...VFR CONDITIONS SHOULD PREVAIL UNTIL AROUND 10Z.
EXPECT A QUICK DROP TO LIFR DURING THE MORNING UNDER INCREASING
UPSLOPE NW WINDS...THEN ONLY GRADUAL IMPROVEMENT TO IFR IN THE AFTN
AS -SHRA CONTINUE. NW WIND WILL LIKELY GUST TO AROUND 30KT DURING
THE AFTN.

AT KSAW...UNTIL ARRIVAL OF SHRA FROM THE S...VFR CONDITIONS WILL
PREVAIL FOR THE NEXT FEW HRS. ARRIVAL OF SHRA AND WINDS BACKING
AROUND TO AN UPSLOPE NE TO N DIRECTION OFF LAKE SUPERIOR WILL RESULT
IN CONDITIONS QUICKLY FALLING TO LIFR BEFORE 12Z. AS WINDS BACK TO
THE NW AND THEN W IN THE AFTN AND PCPN DIMINISHES...EXPECT
IMPROVEMENT TO MVFR. MIGHT EVEN SEE A PERIOD OF VFR LATE AFTN/EARLY
EVENING.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT MON APR 20 2015

AS A LOW LIFTS THROUGH THE SOO THIS AFTERNOON...WINDS WILL BACK TO
THE WEST-NORTHWEST THIS AFTERNOON. WITH THE LOW BECOMING STATIONARY
JUST TO THE SOUTHWEST OF JAMES BAY TONIGHT THROUGH
WEDNESDAY...PERSISTENT NORTHWESTERLY WINDS OF 20-30KTS ARE EXPECTED.
ALTHOUGH THE LOW WILL WEAKEN AND MOVE EAST ACROSS QUEBEC WEDNESDAY
NIGHT INTO THURSDAY...THE NORTHWEST WINDS UP TO 25KTS WILL PERSIST
AS A RIDGE MOVES INTO THE NORTHERN PLAINS. THE WINDS DIMINISH THEN
BELOW 20 KNOTS BY THURSDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...KF
AVIATION...ROLFSON
MARINE...07



000
FXUS63 KMQT 200909
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
509 AM EDT MON APR 20 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT MON APR 20 2015

UPPER AIR PATTERN CONSISTS OF A ELONGATED 500 MB TROUGH WITH SEVERAL
SHORTWAVES EMBEDDED IN IT. THE SHORTWAVE OVER LOWER MICHIGAN WILL BE
SPREADING PCPN UP INTO THE CWA THIS MORNING WHILE ANOTHER SHORTWAVE
OVER THE RED RIVER VALLEY OF THE NORTH WILL PUT PCPN IN OVER THE FAR
WEST THIS MORNING. BOTH THESE SHORTWAVES WILL COMBINE OVER THE AREA
AND CAUSE SOME WIDESPREAD PCPN THIS MORNING OVER THE CWA. UPPER
TROUGH SLOWLY MOVES EAST WITH A 500 MB LOW MOVING OVER THE U.P. LATE
TONIGHT. NAM SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE OVER THE CWA THIS MORNING. THE DEEPER MOISTURE REMAIN
OVER THE AREA THROUGH TONIGHT WHILE THE Q-VECTOR CONVERGENCE WEAKENS
AND MOVES OUT BY THIS EVENING BEFORE MOVING BACK IN LATE TONIGHT
WITH THE 500 MB LOW. GFS AND ECMWF SHOW ABOUT THE SAME THING AS
WELL.

HAD TO HANG ONTO THE DRIER AIR ACROSS THE CENTRAL CWA A BIT LONGER
THIS MORNING AND CUT THE QPF AMOUNTS BECAUSE OF THIS. DID GO WITH A
COMBO OF WET BULB HEIGHTS AND WARM TEMPERATURES ALOFT TO DETERMINE
SNOW FOR THIS FORECAST AND LOOKS LIKE THE ACCUMULATING SNOW WILL BE
TONIGHT WHERE UP TO 2 INCHES COULD FALL ACROSS THE WESTERN
HIGHLANDS. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
TEMPERATURE FORECAST AND WENT WITH CATEGORICAL POPS FOR TODAY FOR
THE CWA AND THEN LIKELY POPS IN NORTHWEST LAKE EFFECT BELTS TONIGHT
AND KEPT SOME SLIGHT CHANCE POPS IN THE FAR SOUTH DUE TO THE UPPER
LOW MOVING INTO THE AREA AND WRAPAROUND PCPN IN THE AREA.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 507 AM EDT MON APR 20 2015

COLDER...WITH LITTLE BREAK IN IN THE NEAR FUTURE. THE BEST CHANCE OF
LIGHT PRECIP WILL BE ALONG THE LAKE SUPERIOR SHORELINE.

AT 12Z TUESDAY THE SFC LOW WILL HAVE SHIFTED TO JUST W OF JAMES
BAY...WITH A TROUGH/SECONDARY COLD FRONT EXTENDING OVER CENTRAL LAKE
SUPERIOR AND CENTRAL UPPER MI. 850MB TEMPS AHEAD OF THE TROUGH WILL
AVERAGE AROUND -4C...AND FALL TO AROUND -7C BY THE END OF THE DAY
BEHIND THE TROUGH. THIS WILL COINCIDE WITH THE PASSAGE OF THE LARGE
500MB LOW...CENTERED OVER THE CWA TUESDAY. THE SIZABLE TROUGH WILL
ENCOMPASS E MT THROUGH THE GULF STATES...AND BACK UP THROUGH THE NEW
ENGLAND STATES.

THE 500MB LOW WILL NOT MOVE MUCH...ONLY TO E ONTARIO BY THURSDAY
MORNING. THIS WILL BE SIMILAR TO THE SFC LOW WHICH WILL ONLY SHIFT
TO FAR W ONTARIO DURING THE SAME TIME. LOOK FOR PERSISTENT NW WINDS
AND 850MB TEMPS OF -8 TO -12C.

THE 500MB LOW WILL CONTINUE ITS E PROGRESSION THURSDAY NIGHT THROUGH
FRIDAY...MOVING ACROSS S QUEBEC. WHILE A WEAK RIDGE WILL ATTEMPT TO
BUILD OVER FAR W LAKE SUPERIOR/UPPER MI...THE TROUGH WILL STILL
REMAIN OVER THE E. WHILE THE SFC LOW INITIALLY SHIFTS TO SE QUEBEC
EARLY THURSDAY EVENING...IT LOOKS TO SHIFT BACK W DURING THE DAY
FRIDAY /PARTICULARLY OFF THE GFS SOLUTION/.

THERE LOOKS TO BE SOME DISCREPANCIES IN THE HANDLING OF THE 500MB
LOW FOR THE LATTER HALF OF THE WEEKEND BY THE 00Z MODEL RUNS. WHILE
THE ECMWF PUSHES A RIDGE OVER THE UPPER GREAT LAKES SATURDAY AND
SUNDAY...THE GFS KEEPS THE TROUGH IN PLACE. AS A RESULT...FEW
CHANGES WERE MADE TO THE ONGOING FCST FOR THE WEEKEND. TEMPS MAY
RISE AROUND 5F SUNDAY COMPARED TO SATURDAY...BUT WAS LACKING
CONFIDENCE TO DO MUCH MORE THAN THAT. THE ECMWF SOLUTION WOULD BRING
850MB TEMPS BACK TO -2C BY SATURDAY AFTERNOON WITH THAT RIDGE
BUILDING IN. HOWEVER...THE GFS IS STILL AROUND -8C.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 106 AM EDT MON APR 20 2015

LOW PRES OVER SW MI WILL LIFT N TODAY WHILE A LOW PRES TROF MOVES E
AND MERGES WITH THE LOW. THESE 2 FEATURES WILL SPREAD SHRA ACROSS
THE AREA OVERNIGHT...BRINGING DETERIORATING CONDITIONS.

SFC TROF HAS ALREADY PASSED KIWD. WITH RAIN OVER THE COLD LAKE
WATERS AND AN UPSLOPE NW WIND...LIFR CONDITIONS WILL LIKELY PREVAIL
THRU THE MORNING HRS. THE -SHRA WILL MIX WITH OR CHANGE TO -SHSN
AROUND MID MORNING. PCPN WILL THEN DIMINISH IN THE AFTN WITH
CONDITIONS IMPROVING TO MVFR UNDER GUSTY WNW WINDS. MIGHT EVEN SEE A
PERIOD OF VFR CONDITIONS. ANOTHER DISTURBANCE MAY BRING
DETERIORATING CONDITIONS AGAIN LATE THIS EVENING.

AT KCMX...WITH MAIN AREA OF PCPN AND SFC TROF NOT ARRIVING UNTIL
AROUND DAYBREAK...VFR CONDITIONS SHOULD PREVAIL UNTIL AROUND 10Z.
EXPECT A QUICK DROP TO LIFR DURING THE MORNING UNDER INCREASING
UPSLOPE NW WINDS...THEN ONLY GRADUAL IMPROVEMENT TO IFR IN THE AFTN
AS -SHRA CONTINUE. NW WIND WILL LIKELY GUST TO AROUND 30KT DURING
THE AFTN.

AT KSAW...UNTIL ARRIVAL OF SHRA FROM THE S...VFR CONDITIONS WILL
PREVAIL FOR THE NEXT FEW HRS. ARRIVAL OF SHRA AND WINDS BACKING
AROUND TO AN UPSLOPE NE TO N DIRECTION OFF LAKE SUPERIOR WILL RESULT
IN CONDITIONS QUICKLY FALLING TO LIFR BEFORE 12Z. AS WINDS BACK TO
THE NW AND THEN W IN THE AFTN AND PCPN DIMINISHES...EXPECT
IMPROVEMENT TO MVFR. MIGHT EVEN SEE A PERIOD OF VFR LATE AFTN/EARLY
EVENING.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT MON APR 20 2015

AS A LOW LIFTS THROUGH THE SOO THIS AFTERNOON...WINDS WILL BACK TO
THE WEST-NORTHWEST THIS AFTERNOON. WITH THE LOW BECOMING STATIONARY
JUST TO THE SOUTHWEST OF JAMES BAY TONIGHT THROUGH
WEDNESDAY...PERSISTENT NORTHWESTERLY WINDS OF 20-30KTS ARE EXPECTED.
ALTHOUGH THE LOW WILL WEAKEN AND MOVE EAST ACROSS QUEBEC WEDNESDAY
NIGHT INTO THURSDAY...THE NORTHWEST WINDS UP TO 25KTS WILL PERSIST
AS A RIDGE MOVES INTO THE NORTHERN PLAINS. THE WINDS DIMINISH THEN
BELOW 20 KNOTS BY THURSDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...KF
AVIATION...ROLFSON
MARINE...07




000
FXUS63 KDTX 200753
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
353 AM EDT MON APR 20 2015

.SHORT TERM...TODAY AND TONIGHT

THE WELL ADVERTISED STRONG LOW PRESSURE SYSTEM HAS LIFTED INTO SW
LOWER MI AS OF 07Z THIS MORNING. IT WILL CONTINUE NORTHWARD REACHING
ONTARIO BY 00Z THIS EVENING. ALTHOUGH THE MAIN WING OF ISENTROPIC
ASCENT NORTH OF THE WARM FRONT AND COLOCATED RIBBON OF ENHANCED
MOISTURE IS NORTH OF SE MI...ELEVATED MOISTURE VALUES WILL LINGER
INTO THE EARLY AFTERNOON AS IT APPEARS THE EASTERN PORTION OF THE
CWA SHOULD RESIDE IN THE WARM SECTOR FOR SEVERAL HOURS. HOW THE
AFTERNOON WILL SHAPE UP WILL DEPEND ON A COMPACT SHORTWAVE ROTATING
AROUND THE BASE THE MID LEVEL TROUGH WHICH IS OVER THE UPPER
MISSISSIPPI VALLEY AND WILL SWING THROUGH THE OHIO VALLEY LATER
TODAY. THIS SHORTWAVE IS FORECAST TO LIFT SOMEWHERE THROUGH SE LOWER
MI OR WESTERN LAKE ERIE. THIS HAS BIG IMPLICATIONS ON THE FORECAST
DUE TO THE TIMING OF THE COLD FRONT THIS SECONDARY LOW WILL PULL
THROUGH THE AREA. CURRENTLY MODELS HAVE THE TIMING FAIRLY WELL
PEGGED DOWN TO THE 18-21Z TIMEFRAME. THIS WOULD ALLOW ENOUGH DIURNAL
HEATING TO POTENTIALLY BUILD UP A FEW HUNDRED J/KG OF CAPE AHEAD OF
THE APPROACHING COLD FRONT WITH VERY FAVORABLE LL LAPSE RATES AND
DEEP LAYER OF STRONG SW FLOW WITH SPEED SHEAR SETTING UP IN THE WARM
SECTOR. SPC HAS EXPANDED THE MARGINAL AREA TO INCLUDE A SLIVER OF
EXTREME EASTERN LOWER MI...EAST OF A LINE FROM ABOUT ADRIAN TO PORT
HURON. THERE IS CONCERN AS TO WHETHER THIS WILL ACTUALLY CONCERN AS
THE NAM/GEMREG/HRRR/ETC... SUGGEST THAT THE LL JET MAX WILL DRIFT
EASTWARD AND IGNITE THE COLD FRONT JUST SE OF MI LEAVING US WITH
ONLY RESIDUAL SHOWERS AND ISOLATED RUMBLES OF THUNDER AS THE FRONTAL
BOUNDARIES OCCLUDE AND SLIDE THROUGH THE AREA WITH THE TRIPLE POINT
STAYING SOUTH. AFTER SEVERAL MODEL RUNS TRENDING WESTWARD...THE
RECENT RUNS ARE STALLING IF NOT SHIFTING SLIGHTLY FURTHER EAST WHICH
LENDS CREDENCE THUNDERSTORM POTENTIAL DOUBTS. OVERALL THINK WE WILL
GET BRUSHED WITH SOME THUNDERSTORMS BUT THE BETTER ORGANIZED STORMS
WILL LIKELY STAY OUT OF THE AREA.

IN ADDITION TO COLD FRONTAL THUNDERSTORM POTENTIAL...WINDS WILL BE
QUITE GUSTY THROUGH THE DAY. THE DEEP MIXED LAYER WITH 900MB WINDS
MAKING A RUN AT 40 KNOTS WILL KEEP SW SFC FLOW AROUND 20KT WITH
GUSTS APPROACHING 35 KNOTS...ESPECIALLY EARLY THIS AFTERNOON EAST OF
THE FRONT.

AS THE FOR THE REST OF THE EVENING AND INTO THE OVERNIGHT...THE COLD
FRONT...OR OCCLUDED FRONT...WILL USHER IN MUCH COOLER AIR WHILE
KEEPING THE MIXED LAYER IN TACK THROUGH THE NIGHT WHICH WILL IN TURN
KEEP WINDS ELEVATED. THE ENHANCED MOISTURE PLUME WILL BE SHUNTED
EAST BUT SCATTERED SHOWERS WILL LINGER THROUGH THE OVERNIGHT AS CAA
RESULTS IN MORE FAVORABLE MID LEVEL LAPSE RATES. THE MIXING AND
CLOUD COVER WILL KEEP MIN TEMPS UP AROUND 40 FOR MOST LOCATIONS.

&&

.LONG TERM...

CLOSED UPPER LOW WILL REMAIN PARKED OVERHEAD THROUGH MIDWEEK.
EMBEDDED SHORTWAVES WILL BRING EPISODIC SHOWER ACTIVITY, THE TIMING
OF WHICH WILL REMAIN INHERENTLY ILL-DEFINED OUTSIDE OF 48 HOURS. A
COLD COLUMN AND CLOUD COVER WILL KEEP TEMPERATURES SOLIDLY BELOW
NORMAL.

LOW CENTER WILL MEANDER FROM INTERNATIONAL FALLS THIS AFTN TO THE
STRAITS BY MIDDAY TUESDAY. APRIL INSOLATION AND VERY COLD H5 TEMPS
WITHIN THE MID-LEVEL COLD POOL OF -30C WILL RESULT IN A DEEP MIXED
LAYER PERHAPS APPROACHING 600MB. ROBUST WSW WIND FIELD WITHIN THIS
VERY WELL-MIXED ENVIRONMENT WILL SET THE STAGE FOR WIDESPREAD WIND
GUSTS IN EXCESS OF 30 KNOTS FOR THE BALANCE OF TUESDAY AFTERNOON.
THE TRADE-OFF OF THE DEEP MIXING WILL BE TEMPERATURES REACHING THE
LOW 50S IN SPITE OF SUB-ZERO 850MB TEMPERATURES. SUFFICIENT MID-
LEVEL MOISTURE RESIDING IN THE 800-600MB LAYER WILL RESULT IN, AT
MINIMUM, WIDESPREAD AFTERNOON CLOUDS. MODELS ALSO POINT TO MID-
MORNING SHOWER GENERATION AS WELL, GIVEN A FEW HUNDRED J/KG CAPE
AVAILABLE FOR SURFACE BASED PARCELS. PASSING ELONGATED H4 PV ANOMALY
WILL PROVIDE BROAD SCALE ASCENT WHILE INLAND TROUGHING HELPS IS
NOTED TO HELP FOCUS ACTIVITY ALONG/NORTH OF M59. CLASSIC INVERTED V
THERMODYNAMIC PROFILE WILL ALLOW SHOWERS TO POTENTIALLY PRODUCE WIND
GUSTS OF 45 KTS.

LOSS OF DIURNAL HEATING WILL MEAN AN END TO SHOWERS TUESDAY EVENING.
THE GRADIENT WILL REMAIN ELEVATED AS BROAD LOW PRESSURE REMAINS
CENTERED OVER THE GREAT LAKES. COMBINED WITH CLOUDS, LOW
TEMPERATURES WILL BE COLD - BUT NOT AS COLD AS THEY COULD BE GIVEN
THE AIRMASS. PREFER NAM12 DEPICTION OF 34-38F TUESDAY NIGHT.

LITTLE CHANGE IN SYNOPTIC SCALE REGIME FOR WEDNESDAY, MEANING
CONTINUED DIURNALLY DRIVEN BOUNDARY LAYER CLOUD COVER AND AFTERNOON
WIND GUSTS IN THE 25-30 KT RANGE FROM THE WEST. BETTER LOW-LEVEL
MOISTURE QUALITY WILL BE OFFSET BY LACK OF FOCUSED FORCING, BUT HAVE
TO RESPECT POTENTIAL WITH A LOW END CHC POP. THE MOST NOTEWORTHY
CHANGE BY WED WILL BE POSITION OF THE THERMAL TROUGH OVERHEAD AS H85
TEMPERATURES FALL TO -6 TO -7C SUPPORTING HIGHS IN THE MID 40S AND
WIND CHILLS IN THE MID 30S.

&&

.MARINE...

FRESH TO LOCALLY STRONG SOUTHEAST WINDS WILL VEER TO THE SOUTHWEST
THROUGH TODAY. A FEW GUSTS TO NEAR GALES WILL BE POSSIBLE...MAINLY
IN NEARSHORE ZONES INCLUDING LAKE SAINT CLAIR AND ERIE. SMALL CRAFT
ADVISORIES THEREFORE REMAIN IN EFFECT FOR ALL NEARSHORE ZONES.
BREEZY WESTERLY WINDS WILL PERSIST THROUGH MIDWEEK AS CONDITIONS
REMAIN RELATIVELY STATIC WITH LOW PRESSURE PARKED OVER THE GREAT
LAKES. ADDITIONAL SMALL CRAFT ADVISORIES FOR WIND WILL LIKELY BE
NEEDED ON TUESDAY AND POSSIBLY ONCE MORE ON WEDNESDAY.

&&

.AVIATION...ISSUED 1151 PM EDT SUN APR 19 2015

LOW PRESSURE WILL ADVANCE ACROSS WRN LOWER MI OVERNIGHT INTO MON
MORNING. PERIODIC SHOWERS WILL PERSIST DURING MUCH OF THE OVERNIGHT.
CEILINGS WILL CONTINUE TO TREND LOWER AS THIS LOW PRESSURE SYSTEM
DRIVES ADDITIONAL LOW LEVEL MOISTURE INTO SE MI. GIVEN UPSTREAM
OBSERVATIONS...FLUCTUATIONS BETWEEN LOW END MVFR AND IFR LOOK TO
PREVAIL AT LEAST UNTIL THE PASSAGE OF THE SFC WARM FRONT BETWEEN 09Z
AND 11Z. WINDS WILL VEER TOWARD THE S-SW WITH THE PASSAGE OF THIS
FRONT AND CEILINGS MAY ACTUALLY IMPROVE A LITTLE AS THE WARM SECTOR
SLIDES INTO SE MI. THE GRADIENT ASSOCIATED WITH THIS SYSTEM WILL
MAINTAIN GUSTY WINDS THROUGH MON AFTERNOON...WITH FREQUENT GUSTS
OVER 20 KNOTS EXPECTED.

FOR DTW...THE WARM FRONT WILL MOVE ACROSS METRO AROUND 09Z. WIND
GUSTS WITHIN THE S-SW FLOW OF THE WARM SECTOR ARE LIKELY TO TOP 25
KNOTS WELL INTO MON AFTERNOON.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS AOB 5KFT TONIGHT AND MONDAY.

* LOW IN THUNDERSTORMS TONIGHT AND MONDAY AFTERNOON.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LHZ421-422-
     441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LEZ444.

&&

$$

SHORT TERM...DRK
LONG TERM....JVC
MARINE.......JVC
AVIATION.....SC


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).



000
FXUS63 KDTX 200753
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
353 AM EDT MON APR 20 2015

.SHORT TERM...TODAY AND TONIGHT

THE WELL ADVERTISED STRONG LOW PRESSURE SYSTEM HAS LIFTED INTO SW
LOWER MI AS OF 07Z THIS MORNING. IT WILL CONTINUE NORTHWARD REACHING
ONTARIO BY 00Z THIS EVENING. ALTHOUGH THE MAIN WING OF ISENTROPIC
ASCENT NORTH OF THE WARM FRONT AND COLOCATED RIBBON OF ENHANCED
MOISTURE IS NORTH OF SE MI...ELEVATED MOISTURE VALUES WILL LINGER
INTO THE EARLY AFTERNOON AS IT APPEARS THE EASTERN PORTION OF THE
CWA SHOULD RESIDE IN THE WARM SECTOR FOR SEVERAL HOURS. HOW THE
AFTERNOON WILL SHAPE UP WILL DEPEND ON A COMPACT SHORTWAVE ROTATING
AROUND THE BASE THE MID LEVEL TROUGH WHICH IS OVER THE UPPER
MISSISSIPPI VALLEY AND WILL SWING THROUGH THE OHIO VALLEY LATER
TODAY. THIS SHORTWAVE IS FORECAST TO LIFT SOMEWHERE THROUGH SE LOWER
MI OR WESTERN LAKE ERIE. THIS HAS BIG IMPLICATIONS ON THE FORECAST
DUE TO THE TIMING OF THE COLD FRONT THIS SECONDARY LOW WILL PULL
THROUGH THE AREA. CURRENTLY MODELS HAVE THE TIMING FAIRLY WELL
PEGGED DOWN TO THE 18-21Z TIMEFRAME. THIS WOULD ALLOW ENOUGH DIURNAL
HEATING TO POTENTIALLY BUILD UP A FEW HUNDRED J/KG OF CAPE AHEAD OF
THE APPROACHING COLD FRONT WITH VERY FAVORABLE LL LAPSE RATES AND
DEEP LAYER OF STRONG SW FLOW WITH SPEED SHEAR SETTING UP IN THE WARM
SECTOR. SPC HAS EXPANDED THE MARGINAL AREA TO INCLUDE A SLIVER OF
EXTREME EASTERN LOWER MI...EAST OF A LINE FROM ABOUT ADRIAN TO PORT
HURON. THERE IS CONCERN AS TO WHETHER THIS WILL ACTUALLY CONCERN AS
THE NAM/GEMREG/HRRR/ETC... SUGGEST THAT THE LL JET MAX WILL DRIFT
EASTWARD AND IGNITE THE COLD FRONT JUST SE OF MI LEAVING US WITH
ONLY RESIDUAL SHOWERS AND ISOLATED RUMBLES OF THUNDER AS THE FRONTAL
BOUNDARIES OCCLUDE AND SLIDE THROUGH THE AREA WITH THE TRIPLE POINT
STAYING SOUTH. AFTER SEVERAL MODEL RUNS TRENDING WESTWARD...THE
RECENT RUNS ARE STALLING IF NOT SHIFTING SLIGHTLY FURTHER EAST WHICH
LENDS CREDENCE THUNDERSTORM POTENTIAL DOUBTS. OVERALL THINK WE WILL
GET BRUSHED WITH SOME THUNDERSTORMS BUT THE BETTER ORGANIZED STORMS
WILL LIKELY STAY OUT OF THE AREA.

IN ADDITION TO COLD FRONTAL THUNDERSTORM POTENTIAL...WINDS WILL BE
QUITE GUSTY THROUGH THE DAY. THE DEEP MIXED LAYER WITH 900MB WINDS
MAKING A RUN AT 40 KNOTS WILL KEEP SW SFC FLOW AROUND 20KT WITH
GUSTS APPROACHING 35 KNOTS...ESPECIALLY EARLY THIS AFTERNOON EAST OF
THE FRONT.

AS THE FOR THE REST OF THE EVENING AND INTO THE OVERNIGHT...THE COLD
FRONT...OR OCCLUDED FRONT...WILL USHER IN MUCH COOLER AIR WHILE
KEEPING THE MIXED LAYER IN TACK THROUGH THE NIGHT WHICH WILL IN TURN
KEEP WINDS ELEVATED. THE ENHANCED MOISTURE PLUME WILL BE SHUNTED
EAST BUT SCATTERED SHOWERS WILL LINGER THROUGH THE OVERNIGHT AS CAA
RESULTS IN MORE FAVORABLE MID LEVEL LAPSE RATES. THE MIXING AND
CLOUD COVER WILL KEEP MIN TEMPS UP AROUND 40 FOR MOST LOCATIONS.

&&

.LONG TERM...

CLOSED UPPER LOW WILL REMAIN PARKED OVERHEAD THROUGH MIDWEEK.
EMBEDDED SHORTWAVES WILL BRING EPISODIC SHOWER ACTIVITY, THE TIMING
OF WHICH WILL REMAIN INHERENTLY ILL-DEFINED OUTSIDE OF 48 HOURS. A
COLD COLUMN AND CLOUD COVER WILL KEEP TEMPERATURES SOLIDLY BELOW
NORMAL.

LOW CENTER WILL MEANDER FROM INTERNATIONAL FALLS THIS AFTN TO THE
STRAITS BY MIDDAY TUESDAY. APRIL INSOLATION AND VERY COLD H5 TEMPS
WITHIN THE MID-LEVEL COLD POOL OF -30C WILL RESULT IN A DEEP MIXED
LAYER PERHAPS APPROACHING 600MB. ROBUST WSW WIND FIELD WITHIN THIS
VERY WELL-MIXED ENVIRONMENT WILL SET THE STAGE FOR WIDESPREAD WIND
GUSTS IN EXCESS OF 30 KNOTS FOR THE BALANCE OF TUESDAY AFTERNOON.
THE TRADE-OFF OF THE DEEP MIXING WILL BE TEMPERATURES REACHING THE
LOW 50S IN SPITE OF SUB-ZERO 850MB TEMPERATURES. SUFFICIENT MID-
LEVEL MOISTURE RESIDING IN THE 800-600MB LAYER WILL RESULT IN, AT
MINIMUM, WIDESPREAD AFTERNOON CLOUDS. MODELS ALSO POINT TO MID-
MORNING SHOWER GENERATION AS WELL, GIVEN A FEW HUNDRED J/KG CAPE
AVAILABLE FOR SURFACE BASED PARCELS. PASSING ELONGATED H4 PV ANOMALY
WILL PROVIDE BROAD SCALE ASCENT WHILE INLAND TROUGHING HELPS IS
NOTED TO HELP FOCUS ACTIVITY ALONG/NORTH OF M59. CLASSIC INVERTED V
THERMODYNAMIC PROFILE WILL ALLOW SHOWERS TO POTENTIALLY PRODUCE WIND
GUSTS OF 45 KTS.

LOSS OF DIURNAL HEATING WILL MEAN AN END TO SHOWERS TUESDAY EVENING.
THE GRADIENT WILL REMAIN ELEVATED AS BROAD LOW PRESSURE REMAINS
CENTERED OVER THE GREAT LAKES. COMBINED WITH CLOUDS, LOW
TEMPERATURES WILL BE COLD - BUT NOT AS COLD AS THEY COULD BE GIVEN
THE AIRMASS. PREFER NAM12 DEPICTION OF 34-38F TUESDAY NIGHT.

LITTLE CHANGE IN SYNOPTIC SCALE REGIME FOR WEDNESDAY, MEANING
CONTINUED DIURNALLY DRIVEN BOUNDARY LAYER CLOUD COVER AND AFTERNOON
WIND GUSTS IN THE 25-30 KT RANGE FROM THE WEST. BETTER LOW-LEVEL
MOISTURE QUALITY WILL BE OFFSET BY LACK OF FOCUSED FORCING, BUT HAVE
TO RESPECT POTENTIAL WITH A LOW END CHC POP. THE MOST NOTEWORTHY
CHANGE BY WED WILL BE POSITION OF THE THERMAL TROUGH OVERHEAD AS H85
TEMPERATURES FALL TO -6 TO -7C SUPPORTING HIGHS IN THE MID 40S AND
WIND CHILLS IN THE MID 30S.

&&

.MARINE...

FRESH TO LOCALLY STRONG SOUTHEAST WINDS WILL VEER TO THE SOUTHWEST
THROUGH TODAY. A FEW GUSTS TO NEAR GALES WILL BE POSSIBLE...MAINLY
IN NEARSHORE ZONES INCLUDING LAKE SAINT CLAIR AND ERIE. SMALL CRAFT
ADVISORIES THEREFORE REMAIN IN EFFECT FOR ALL NEARSHORE ZONES.
BREEZY WESTERLY WINDS WILL PERSIST THROUGH MIDWEEK AS CONDITIONS
REMAIN RELATIVELY STATIC WITH LOW PRESSURE PARKED OVER THE GREAT
LAKES. ADDITIONAL SMALL CRAFT ADVISORIES FOR WIND WILL LIKELY BE
NEEDED ON TUESDAY AND POSSIBLY ONCE MORE ON WEDNESDAY.

&&

.AVIATION...ISSUED 1151 PM EDT SUN APR 19 2015

LOW PRESSURE WILL ADVANCE ACROSS WRN LOWER MI OVERNIGHT INTO MON
MORNING. PERIODIC SHOWERS WILL PERSIST DURING MUCH OF THE OVERNIGHT.
CEILINGS WILL CONTINUE TO TREND LOWER AS THIS LOW PRESSURE SYSTEM
DRIVES ADDITIONAL LOW LEVEL MOISTURE INTO SE MI. GIVEN UPSTREAM
OBSERVATIONS...FLUCTUATIONS BETWEEN LOW END MVFR AND IFR LOOK TO
PREVAIL AT LEAST UNTIL THE PASSAGE OF THE SFC WARM FRONT BETWEEN 09Z
AND 11Z. WINDS WILL VEER TOWARD THE S-SW WITH THE PASSAGE OF THIS
FRONT AND CEILINGS MAY ACTUALLY IMPROVE A LITTLE AS THE WARM SECTOR
SLIDES INTO SE MI. THE GRADIENT ASSOCIATED WITH THIS SYSTEM WILL
MAINTAIN GUSTY WINDS THROUGH MON AFTERNOON...WITH FREQUENT GUSTS
OVER 20 KNOTS EXPECTED.

FOR DTW...THE WARM FRONT WILL MOVE ACROSS METRO AROUND 09Z. WIND
GUSTS WITHIN THE S-SW FLOW OF THE WARM SECTOR ARE LIKELY TO TOP 25
KNOTS WELL INTO MON AFTERNOON.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS AOB 5KFT TONIGHT AND MONDAY.

* LOW IN THUNDERSTORMS TONIGHT AND MONDAY AFTERNOON.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LHZ421-422-
     441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LEZ444.

&&

$$

SHORT TERM...DRK
LONG TERM....JVC
MARINE.......JVC
AVIATION.....SC


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).




000
FXUS63 KDTX 200753
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
353 AM EDT MON APR 20 2015

.SHORT TERM...TODAY AND TONIGHT

THE WELL ADVERTISED STRONG LOW PRESSURE SYSTEM HAS LIFTED INTO SW
LOWER MI AS OF 07Z THIS MORNING. IT WILL CONTINUE NORTHWARD REACHING
ONTARIO BY 00Z THIS EVENING. ALTHOUGH THE MAIN WING OF ISENTROPIC
ASCENT NORTH OF THE WARM FRONT AND COLOCATED RIBBON OF ENHANCED
MOISTURE IS NORTH OF SE MI...ELEVATED MOISTURE VALUES WILL LINGER
INTO THE EARLY AFTERNOON AS IT APPEARS THE EASTERN PORTION OF THE
CWA SHOULD RESIDE IN THE WARM SECTOR FOR SEVERAL HOURS. HOW THE
AFTERNOON WILL SHAPE UP WILL DEPEND ON A COMPACT SHORTWAVE ROTATING
AROUND THE BASE THE MID LEVEL TROUGH WHICH IS OVER THE UPPER
MISSISSIPPI VALLEY AND WILL SWING THROUGH THE OHIO VALLEY LATER
TODAY. THIS SHORTWAVE IS FORECAST TO LIFT SOMEWHERE THROUGH SE LOWER
MI OR WESTERN LAKE ERIE. THIS HAS BIG IMPLICATIONS ON THE FORECAST
DUE TO THE TIMING OF THE COLD FRONT THIS SECONDARY LOW WILL PULL
THROUGH THE AREA. CURRENTLY MODELS HAVE THE TIMING FAIRLY WELL
PEGGED DOWN TO THE 18-21Z TIMEFRAME. THIS WOULD ALLOW ENOUGH DIURNAL
HEATING TO POTENTIALLY BUILD UP A FEW HUNDRED J/KG OF CAPE AHEAD OF
THE APPROACHING COLD FRONT WITH VERY FAVORABLE LL LAPSE RATES AND
DEEP LAYER OF STRONG SW FLOW WITH SPEED SHEAR SETTING UP IN THE WARM
SECTOR. SPC HAS EXPANDED THE MARGINAL AREA TO INCLUDE A SLIVER OF
EXTREME EASTERN LOWER MI...EAST OF A LINE FROM ABOUT ADRIAN TO PORT
HURON. THERE IS CONCERN AS TO WHETHER THIS WILL ACTUALLY CONCERN AS
THE NAM/GEMREG/HRRR/ETC... SUGGEST THAT THE LL JET MAX WILL DRIFT
EASTWARD AND IGNITE THE COLD FRONT JUST SE OF MI LEAVING US WITH
ONLY RESIDUAL SHOWERS AND ISOLATED RUMBLES OF THUNDER AS THE FRONTAL
BOUNDARIES OCCLUDE AND SLIDE THROUGH THE AREA WITH THE TRIPLE POINT
STAYING SOUTH. AFTER SEVERAL MODEL RUNS TRENDING WESTWARD...THE
RECENT RUNS ARE STALLING IF NOT SHIFTING SLIGHTLY FURTHER EAST WHICH
LENDS CREDENCE THUNDERSTORM POTENTIAL DOUBTS. OVERALL THINK WE WILL
GET BRUSHED WITH SOME THUNDERSTORMS BUT THE BETTER ORGANIZED STORMS
WILL LIKELY STAY OUT OF THE AREA.

IN ADDITION TO COLD FRONTAL THUNDERSTORM POTENTIAL...WINDS WILL BE
QUITE GUSTY THROUGH THE DAY. THE DEEP MIXED LAYER WITH 900MB WINDS
MAKING A RUN AT 40 KNOTS WILL KEEP SW SFC FLOW AROUND 20KT WITH
GUSTS APPROACHING 35 KNOTS...ESPECIALLY EARLY THIS AFTERNOON EAST OF
THE FRONT.

AS THE FOR THE REST OF THE EVENING AND INTO THE OVERNIGHT...THE COLD
FRONT...OR OCCLUDED FRONT...WILL USHER IN MUCH COOLER AIR WHILE
KEEPING THE MIXED LAYER IN TACK THROUGH THE NIGHT WHICH WILL IN TURN
KEEP WINDS ELEVATED. THE ENHANCED MOISTURE PLUME WILL BE SHUNTED
EAST BUT SCATTERED SHOWERS WILL LINGER THROUGH THE OVERNIGHT AS CAA
RESULTS IN MORE FAVORABLE MID LEVEL LAPSE RATES. THE MIXING AND
CLOUD COVER WILL KEEP MIN TEMPS UP AROUND 40 FOR MOST LOCATIONS.

&&

.LONG TERM...

CLOSED UPPER LOW WILL REMAIN PARKED OVERHEAD THROUGH MIDWEEK.
EMBEDDED SHORTWAVES WILL BRING EPISODIC SHOWER ACTIVITY, THE TIMING
OF WHICH WILL REMAIN INHERENTLY ILL-DEFINED OUTSIDE OF 48 HOURS. A
COLD COLUMN AND CLOUD COVER WILL KEEP TEMPERATURES SOLIDLY BELOW
NORMAL.

LOW CENTER WILL MEANDER FROM INTERNATIONAL FALLS THIS AFTN TO THE
STRAITS BY MIDDAY TUESDAY. APRIL INSOLATION AND VERY COLD H5 TEMPS
WITHIN THE MID-LEVEL COLD POOL OF -30C WILL RESULT IN A DEEP MIXED
LAYER PERHAPS APPROACHING 600MB. ROBUST WSW WIND FIELD WITHIN THIS
VERY WELL-MIXED ENVIRONMENT WILL SET THE STAGE FOR WIDESPREAD WIND
GUSTS IN EXCESS OF 30 KNOTS FOR THE BALANCE OF TUESDAY AFTERNOON.
THE TRADE-OFF OF THE DEEP MIXING WILL BE TEMPERATURES REACHING THE
LOW 50S IN SPITE OF SUB-ZERO 850MB TEMPERATURES. SUFFICIENT MID-
LEVEL MOISTURE RESIDING IN THE 800-600MB LAYER WILL RESULT IN, AT
MINIMUM, WIDESPREAD AFTERNOON CLOUDS. MODELS ALSO POINT TO MID-
MORNING SHOWER GENERATION AS WELL, GIVEN A FEW HUNDRED J/KG CAPE
AVAILABLE FOR SURFACE BASED PARCELS. PASSING ELONGATED H4 PV ANOMALY
WILL PROVIDE BROAD SCALE ASCENT WHILE INLAND TROUGHING HELPS IS
NOTED TO HELP FOCUS ACTIVITY ALONG/NORTH OF M59. CLASSIC INVERTED V
THERMODYNAMIC PROFILE WILL ALLOW SHOWERS TO POTENTIALLY PRODUCE WIND
GUSTS OF 45 KTS.

LOSS OF DIURNAL HEATING WILL MEAN AN END TO SHOWERS TUESDAY EVENING.
THE GRADIENT WILL REMAIN ELEVATED AS BROAD LOW PRESSURE REMAINS
CENTERED OVER THE GREAT LAKES. COMBINED WITH CLOUDS, LOW
TEMPERATURES WILL BE COLD - BUT NOT AS COLD AS THEY COULD BE GIVEN
THE AIRMASS. PREFER NAM12 DEPICTION OF 34-38F TUESDAY NIGHT.

LITTLE CHANGE IN SYNOPTIC SCALE REGIME FOR WEDNESDAY, MEANING
CONTINUED DIURNALLY DRIVEN BOUNDARY LAYER CLOUD COVER AND AFTERNOON
WIND GUSTS IN THE 25-30 KT RANGE FROM THE WEST. BETTER LOW-LEVEL
MOISTURE QUALITY WILL BE OFFSET BY LACK OF FOCUSED FORCING, BUT HAVE
TO RESPECT POTENTIAL WITH A LOW END CHC POP. THE MOST NOTEWORTHY
CHANGE BY WED WILL BE POSITION OF THE THERMAL TROUGH OVERHEAD AS H85
TEMPERATURES FALL TO -6 TO -7C SUPPORTING HIGHS IN THE MID 40S AND
WIND CHILLS IN THE MID 30S.

&&

.MARINE...

FRESH TO LOCALLY STRONG SOUTHEAST WINDS WILL VEER TO THE SOUTHWEST
THROUGH TODAY. A FEW GUSTS TO NEAR GALES WILL BE POSSIBLE...MAINLY
IN NEARSHORE ZONES INCLUDING LAKE SAINT CLAIR AND ERIE. SMALL CRAFT
ADVISORIES THEREFORE REMAIN IN EFFECT FOR ALL NEARSHORE ZONES.
BREEZY WESTERLY WINDS WILL PERSIST THROUGH MIDWEEK AS CONDITIONS
REMAIN RELATIVELY STATIC WITH LOW PRESSURE PARKED OVER THE GREAT
LAKES. ADDITIONAL SMALL CRAFT ADVISORIES FOR WIND WILL LIKELY BE
NEEDED ON TUESDAY AND POSSIBLY ONCE MORE ON WEDNESDAY.

&&

.AVIATION...ISSUED 1151 PM EDT SUN APR 19 2015

LOW PRESSURE WILL ADVANCE ACROSS WRN LOWER MI OVERNIGHT INTO MON
MORNING. PERIODIC SHOWERS WILL PERSIST DURING MUCH OF THE OVERNIGHT.
CEILINGS WILL CONTINUE TO TREND LOWER AS THIS LOW PRESSURE SYSTEM
DRIVES ADDITIONAL LOW LEVEL MOISTURE INTO SE MI. GIVEN UPSTREAM
OBSERVATIONS...FLUCTUATIONS BETWEEN LOW END MVFR AND IFR LOOK TO
PREVAIL AT LEAST UNTIL THE PASSAGE OF THE SFC WARM FRONT BETWEEN 09Z
AND 11Z. WINDS WILL VEER TOWARD THE S-SW WITH THE PASSAGE OF THIS
FRONT AND CEILINGS MAY ACTUALLY IMPROVE A LITTLE AS THE WARM SECTOR
SLIDES INTO SE MI. THE GRADIENT ASSOCIATED WITH THIS SYSTEM WILL
MAINTAIN GUSTY WINDS THROUGH MON AFTERNOON...WITH FREQUENT GUSTS
OVER 20 KNOTS EXPECTED.

FOR DTW...THE WARM FRONT WILL MOVE ACROSS METRO AROUND 09Z. WIND
GUSTS WITHIN THE S-SW FLOW OF THE WARM SECTOR ARE LIKELY TO TOP 25
KNOTS WELL INTO MON AFTERNOON.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS AOB 5KFT TONIGHT AND MONDAY.

* LOW IN THUNDERSTORMS TONIGHT AND MONDAY AFTERNOON.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LHZ421-422-
     441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LEZ444.

&&

$$

SHORT TERM...DRK
LONG TERM....JVC
MARINE.......JVC
AVIATION.....SC


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).



000
FXUS63 KGRR 200730
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
330 AM EDT MON APR 20 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE

.SYNOPSIS...
ISSUED AT 330 AM EDT MON APR 20 2015

A CHILLY WEEK IS DEVELOPING AS LOW PRESSURE HAS MOVED OVER THE GREAT
LAKES. COOLER AIR WILL FLOW INTO WEST MICHIGAN BEHIND THE LOW. RAIN
SHOWERS MAY MIX WITH WET SNOW AT TIMES. MINOR ACCUMULATIONS ARE
POSSIBLE TUESDAY NIGHT NEAR US 10. HIGHS WILL BE IN THE MID 40S TO
MID 50S THROUGH THE END OF THE WEEK.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

FORECAST CONCERNS CONTINUE TO DEAL WITH THE EVOLUTION OF THE LOW
MOVING ACROSS LOWER MICHIGAN. OVERALL...THE FORECAST IS UNFOLDING AS
EXPECTED.

LOCAL AND REGIONAL RADAR SHOWS RAIN SHOWERS MOVING NORTH ACROSS THE
CWA. OVERALL COVERAGE THOUGH IS BEGINNING TO DECREASE SOUTH OF THE
MI/IN BORDER AS THE LOW MOVES NORTH. SREF SHOWS THAT PCPN WILL FILL
BACK IN ACROSS THE SOUTHERN CWA LATER THIS MORNING AS A SHORT WAVE
ALOFT PIVOTS TOWARD LOWER MICHIGAN BEFORE DIMINISHING AGAIN LATER
THIS AFTERNOON. AT THIS POINT THE HEAVIEST AND STEADIEST RAIN
APPEARS TO BE WINDING DOWN. WHAT WE/LL BE LEFT WITH IS SCATTERED TO
NUMEROUS SHOWERS TODAY AND A BIT LESS TONIGHT.

TUESDAY THE CORE OF THE UPPER LOW MOVES OVERHEAD. LOOK FOR PCPN TO
INCREASE IN COVERAGE AGAIN AS INSTABILITY ALOFT INCREASES A BIT DUE
STEEPENING LAPSE RATES COURTESY OF H5 TEMPS NEAR -30C MOVING OVER
THE CWA. THE COLDER AIR WILL REMAIN WITH US THROUGH TUESDAY NIGHT.
THAT/S WHEN WE COULD SEE SOME WET SNOW MIX IN WITH THE RAIN SHOWERS.
MINOR...LESS THAN AN INCH...ACCUMS SEEM POSSIBLE IN OSCEOLA/CLARE
COUNTIES TUESDAY NIGHT. THE UPPER LOW WILL BE VERY SLOW TO MOVE OUT
AND WE/LL SEE THE COOL SHOWERY PCPN CONTINUE WEDNESDAY AS A COUPLE
OF SHORT WAVES ROTATE AROUND THE UPPER LOW AND ACROSS LOWER MICHIGAN.

HIGHS WILL BE BELOW NORMAL THROUGH THE SHORT TERM RANGING FROM THE
MID 40S TO MID 50S.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

THE COLD UPPER LOW REMAINS OVERHEAD THROUGH THURSDAY THEN MOVES INTO
NEW ENGLAND/SRN QUEBEC FOR THE WEEKEND. A SLIGHT CHANCE OF LIGHT
RAIN AND SNOW SHOWERS WILL LINGER THROUGH ABOUT THURSDAY NIGHT WHILE
H8 TEMPS AROUND -7C AND CYCLONIC FLOW ARE STILL PRESENT... OTHERWISE
DRY BUT CHILLY WEATHER IS EXPECTED WITH SFC HIGH PRESSURE MOVING IN.

THIS WEEKEND WE WILL STILL BE ON THE WRN PERIPHERY OF THE BROAD NEW
ENGLAND UPPER LOW. THE CONFLUENT/SHEARING UPPER LEVEL FLOW OVERHEAD
ASSOCIATED WITH THIS FEATURE HELPS TO FEND OFF RAIN ASSOCIATED WITH
A SYSTEM MOVING EAST FROM THE CENTRAL PLAINS. GUIDANCE SHOWS QPF
REMAINING TO OUR SOUTH WITH WEAK SURFACE RIDGING PREVAILING OVER THE
WEEKEND. TEMPERATURES WILL RECOVER A BIT AND HIGHS IN THE 50S ARE
EXPECTED SATURDAY AND SUNDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1242 AM EDT MON APR 20 2015

IFR CEILINGS HAVE SPREAD INTO MOST OF THE TAF SITES AT 05Z AND THE
EXPECTATION IS THAT CEILINGS WILL DIP FURTHER THROUGH THE NIGHT
INTO THE LIFR CATEGORY. POOR AVIATION CONDITIONS WILL EXIST THE
REMAINDER OF THE NIGHT AND MOST OF MONDAY MORNING. CEILINGS WILL
TRY TO LIFT TO MVFR MONDAY AFTERNOON AND POTENTIALLY BECOME VFR
MONDAY EVENING. A LOW MOVING THROUGH THE AREA IS RESPONSIBLE FOR
THE LOW CEILINGS. A LULL IN THE RAIN WILL OCCUR TONIGHT...BUT
ANOTHER ROUND OF SHOWERS ARE EXPECTED FROM MID MORNING MONDAY
THROUGH MONDAY AFTERNOON.

WINDS WILL INCREASE MONDAY AFTERNOON FROM THE SOUTHWEST AT 15 TO
30 KNOTS.


&&

.MARINE...
ISSUED AT 330 AM EDT MON APR 20 2015

LEFT THE HEADLINE AS IS. WINDS ARE ON THE LIGHT SIDE CURRENTLY AS
LOW PRESSURE MOVES OVER LOWER MICHIGAN. AS THE LOW MOVES FARTHER
AWAY...WINDS WILL INCREASE FROM THE SOUTHWEST AND WAVE WILL ALSO
RESPOND. A SMALL CRAFT ADVISORY MAY BE NEEDED NORTH OF WHITEHALL
TONIGHT.

&&

.HYDROLOGY...
ISSUED AT 1114 AM EDT SUN APR 19 2015

PERIODS OF RAIN ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON AND
AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. THE LIGHTER VARIETY OF
PRECIPITATION MAY EXTENT INTO MIDWEEK. THOUGH WE WILL SEE A DECENT
SOIL
SOAKING IT SHOULD NOT BE SUBSTANTIAL ENOUGH TO CREATE FLOODING
CONCERNS. GRADUAL BUT MINOR RISES ARE LIKELY...SUSPECTING THAT
THIS WOULD STAY WITHIN BANKS FOR MOST LOCATIONS. I WOULD NOT RULE
OUT A COUPLE OF SITES FLIRTING WITH ADVISORY STAGE AS WE GO INTO
TUESDAY...ESPECIALLY IF ANY MODERATE RAINFALL IS MORE PERSISTENT
WITH THE FIRST COUPLE OF ROUNDS OF MOISTURE. OTHERWISE...AREA
RIVERS ARE WELL BEHAVED THROUGH THE PERIOD.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...DUKE
HYDROLOGY...JAM
MARINE...04









000
FXUS63 KGRR 200730
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
330 AM EDT MON APR 20 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE

.SYNOPSIS...
ISSUED AT 330 AM EDT MON APR 20 2015

A CHILLY WEEK IS DEVELOPING AS LOW PRESSURE HAS MOVED OVER THE GREAT
LAKES. COOLER AIR WILL FLOW INTO WEST MICHIGAN BEHIND THE LOW. RAIN
SHOWERS MAY MIX WITH WET SNOW AT TIMES. MINOR ACCUMULATIONS ARE
POSSIBLE TUESDAY NIGHT NEAR US 10. HIGHS WILL BE IN THE MID 40S TO
MID 50S THROUGH THE END OF THE WEEK.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

FORECAST CONCERNS CONTINUE TO DEAL WITH THE EVOLUTION OF THE LOW
MOVING ACROSS LOWER MICHIGAN. OVERALL...THE FORECAST IS UNFOLDING AS
EXPECTED.

LOCAL AND REGIONAL RADAR SHOWS RAIN SHOWERS MOVING NORTH ACROSS THE
CWA. OVERALL COVERAGE THOUGH IS BEGINNING TO DECREASE SOUTH OF THE
MI/IN BORDER AS THE LOW MOVES NORTH. SREF SHOWS THAT PCPN WILL FILL
BACK IN ACROSS THE SOUTHERN CWA LATER THIS MORNING AS A SHORT WAVE
ALOFT PIVOTS TOWARD LOWER MICHIGAN BEFORE DIMINISHING AGAIN LATER
THIS AFTERNOON. AT THIS POINT THE HEAVIEST AND STEADIEST RAIN
APPEARS TO BE WINDING DOWN. WHAT WE/LL BE LEFT WITH IS SCATTERED TO
NUMEROUS SHOWERS TODAY AND A BIT LESS TONIGHT.

TUESDAY THE CORE OF THE UPPER LOW MOVES OVERHEAD. LOOK FOR PCPN TO
INCREASE IN COVERAGE AGAIN AS INSTABILITY ALOFT INCREASES A BIT DUE
STEEPENING LAPSE RATES COURTESY OF H5 TEMPS NEAR -30C MOVING OVER
THE CWA. THE COLDER AIR WILL REMAIN WITH US THROUGH TUESDAY NIGHT.
THAT/S WHEN WE COULD SEE SOME WET SNOW MIX IN WITH THE RAIN SHOWERS.
MINOR...LESS THAN AN INCH...ACCUMS SEEM POSSIBLE IN OSCEOLA/CLARE
COUNTIES TUESDAY NIGHT. THE UPPER LOW WILL BE VERY SLOW TO MOVE OUT
AND WE/LL SEE THE COOL SHOWERY PCPN CONTINUE WEDNESDAY AS A COUPLE
OF SHORT WAVES ROTATE AROUND THE UPPER LOW AND ACROSS LOWER MICHIGAN.

HIGHS WILL BE BELOW NORMAL THROUGH THE SHORT TERM RANGING FROM THE
MID 40S TO MID 50S.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

THE COLD UPPER LOW REMAINS OVERHEAD THROUGH THURSDAY THEN MOVES INTO
NEW ENGLAND/SRN QUEBEC FOR THE WEEKEND. A SLIGHT CHANCE OF LIGHT
RAIN AND SNOW SHOWERS WILL LINGER THROUGH ABOUT THURSDAY NIGHT WHILE
H8 TEMPS AROUND -7C AND CYCLONIC FLOW ARE STILL PRESENT... OTHERWISE
DRY BUT CHILLY WEATHER IS EXPECTED WITH SFC HIGH PRESSURE MOVING IN.

THIS WEEKEND WE WILL STILL BE ON THE WRN PERIPHERY OF THE BROAD NEW
ENGLAND UPPER LOW. THE CONFLUENT/SHEARING UPPER LEVEL FLOW OVERHEAD
ASSOCIATED WITH THIS FEATURE HELPS TO FEND OFF RAIN ASSOCIATED WITH
A SYSTEM MOVING EAST FROM THE CENTRAL PLAINS. GUIDANCE SHOWS QPF
REMAINING TO OUR SOUTH WITH WEAK SURFACE RIDGING PREVAILING OVER THE
WEEKEND. TEMPERATURES WILL RECOVER A BIT AND HIGHS IN THE 50S ARE
EXPECTED SATURDAY AND SUNDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1242 AM EDT MON APR 20 2015

IFR CEILINGS HAVE SPREAD INTO MOST OF THE TAF SITES AT 05Z AND THE
EXPECTATION IS THAT CEILINGS WILL DIP FURTHER THROUGH THE NIGHT
INTO THE LIFR CATEGORY. POOR AVIATION CONDITIONS WILL EXIST THE
REMAINDER OF THE NIGHT AND MOST OF MONDAY MORNING. CEILINGS WILL
TRY TO LIFT TO MVFR MONDAY AFTERNOON AND POTENTIALLY BECOME VFR
MONDAY EVENING. A LOW MOVING THROUGH THE AREA IS RESPONSIBLE FOR
THE LOW CEILINGS. A LULL IN THE RAIN WILL OCCUR TONIGHT...BUT
ANOTHER ROUND OF SHOWERS ARE EXPECTED FROM MID MORNING MONDAY
THROUGH MONDAY AFTERNOON.

WINDS WILL INCREASE MONDAY AFTERNOON FROM THE SOUTHWEST AT 15 TO
30 KNOTS.


&&

.MARINE...
ISSUED AT 330 AM EDT MON APR 20 2015

LEFT THE HEADLINE AS IS. WINDS ARE ON THE LIGHT SIDE CURRENTLY AS
LOW PRESSURE MOVES OVER LOWER MICHIGAN. AS THE LOW MOVES FARTHER
AWAY...WINDS WILL INCREASE FROM THE SOUTHWEST AND WAVE WILL ALSO
RESPOND. A SMALL CRAFT ADVISORY MAY BE NEEDED NORTH OF WHITEHALL
TONIGHT.

&&

.HYDROLOGY...
ISSUED AT 1114 AM EDT SUN APR 19 2015

PERIODS OF RAIN ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON AND
AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. THE LIGHTER VARIETY OF
PRECIPITATION MAY EXTENT INTO MIDWEEK. THOUGH WE WILL SEE A DECENT
SOIL
SOAKING IT SHOULD NOT BE SUBSTANTIAL ENOUGH TO CREATE FLOODING
CONCERNS. GRADUAL BUT MINOR RISES ARE LIKELY...SUSPECTING THAT
THIS WOULD STAY WITHIN BANKS FOR MOST LOCATIONS. I WOULD NOT RULE
OUT A COUPLE OF SITES FLIRTING WITH ADVISORY STAGE AS WE GO INTO
TUESDAY...ESPECIALLY IF ANY MODERATE RAINFALL IS MORE PERSISTENT
WITH THE FIRST COUPLE OF ROUNDS OF MOISTURE. OTHERWISE...AREA
RIVERS ARE WELL BEHAVED THROUGH THE PERIOD.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...DUKE
HYDROLOGY...JAM
MARINE...04










000
FXUS63 KGRR 200730
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
330 AM EDT MON APR 20 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE

.SYNOPSIS...
ISSUED AT 330 AM EDT MON APR 20 2015

A CHILLY WEEK IS DEVELOPING AS LOW PRESSURE HAS MOVED OVER THE GREAT
LAKES. COOLER AIR WILL FLOW INTO WEST MICHIGAN BEHIND THE LOW. RAIN
SHOWERS MAY MIX WITH WET SNOW AT TIMES. MINOR ACCUMULATIONS ARE
POSSIBLE TUESDAY NIGHT NEAR US 10. HIGHS WILL BE IN THE MID 40S TO
MID 50S THROUGH THE END OF THE WEEK.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

FORECAST CONCERNS CONTINUE TO DEAL WITH THE EVOLUTION OF THE LOW
MOVING ACROSS LOWER MICHIGAN. OVERALL...THE FORECAST IS UNFOLDING AS
EXPECTED.

LOCAL AND REGIONAL RADAR SHOWS RAIN SHOWERS MOVING NORTH ACROSS THE
CWA. OVERALL COVERAGE THOUGH IS BEGINNING TO DECREASE SOUTH OF THE
MI/IN BORDER AS THE LOW MOVES NORTH. SREF SHOWS THAT PCPN WILL FILL
BACK IN ACROSS THE SOUTHERN CWA LATER THIS MORNING AS A SHORT WAVE
ALOFT PIVOTS TOWARD LOWER MICHIGAN BEFORE DIMINISHING AGAIN LATER
THIS AFTERNOON. AT THIS POINT THE HEAVIEST AND STEADIEST RAIN
APPEARS TO BE WINDING DOWN. WHAT WE/LL BE LEFT WITH IS SCATTERED TO
NUMEROUS SHOWERS TODAY AND A BIT LESS TONIGHT.

TUESDAY THE CORE OF THE UPPER LOW MOVES OVERHEAD. LOOK FOR PCPN TO
INCREASE IN COVERAGE AGAIN AS INSTABILITY ALOFT INCREASES A BIT DUE
STEEPENING LAPSE RATES COURTESY OF H5 TEMPS NEAR -30C MOVING OVER
THE CWA. THE COLDER AIR WILL REMAIN WITH US THROUGH TUESDAY NIGHT.
THAT/S WHEN WE COULD SEE SOME WET SNOW MIX IN WITH THE RAIN SHOWERS.
MINOR...LESS THAN AN INCH...ACCUMS SEEM POSSIBLE IN OSCEOLA/CLARE
COUNTIES TUESDAY NIGHT. THE UPPER LOW WILL BE VERY SLOW TO MOVE OUT
AND WE/LL SEE THE COOL SHOWERY PCPN CONTINUE WEDNESDAY AS A COUPLE
OF SHORT WAVES ROTATE AROUND THE UPPER LOW AND ACROSS LOWER MICHIGAN.

HIGHS WILL BE BELOW NORMAL THROUGH THE SHORT TERM RANGING FROM THE
MID 40S TO MID 50S.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 AM EDT MON APR 20 2015

THE COLD UPPER LOW REMAINS OVERHEAD THROUGH THURSDAY THEN MOVES INTO
NEW ENGLAND/SRN QUEBEC FOR THE WEEKEND. A SLIGHT CHANCE OF LIGHT
RAIN AND SNOW SHOWERS WILL LINGER THROUGH ABOUT THURSDAY NIGHT WHILE
H8 TEMPS AROUND -7C AND CYCLONIC FLOW ARE STILL PRESENT... OTHERWISE
DRY BUT CHILLY WEATHER IS EXPECTED WITH SFC HIGH PRESSURE MOVING IN.

THIS WEEKEND WE WILL STILL BE ON THE WRN PERIPHERY OF THE BROAD NEW
ENGLAND UPPER LOW. THE CONFLUENT/SHEARING UPPER LEVEL FLOW OVERHEAD
ASSOCIATED WITH THIS FEATURE HELPS TO FEND OFF RAIN ASSOCIATED WITH
A SYSTEM MOVING EAST FROM THE CENTRAL PLAINS. GUIDANCE SHOWS QPF
REMAINING TO OUR SOUTH WITH WEAK SURFACE RIDGING PREVAILING OVER THE
WEEKEND. TEMPERATURES WILL RECOVER A BIT AND HIGHS IN THE 50S ARE
EXPECTED SATURDAY AND SUNDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1242 AM EDT MON APR 20 2015

IFR CEILINGS HAVE SPREAD INTO MOST OF THE TAF SITES AT 05Z AND THE
EXPECTATION IS THAT CEILINGS WILL DIP FURTHER THROUGH THE NIGHT
INTO THE LIFR CATEGORY. POOR AVIATION CONDITIONS WILL EXIST THE
REMAINDER OF THE NIGHT AND MOST OF MONDAY MORNING. CEILINGS WILL
TRY TO LIFT TO MVFR MONDAY AFTERNOON AND POTENTIALLY BECOME VFR
MONDAY EVENING. A LOW MOVING THROUGH THE AREA IS RESPONSIBLE FOR
THE LOW CEILINGS. A LULL IN THE RAIN WILL OCCUR TONIGHT...BUT
ANOTHER ROUND OF SHOWERS ARE EXPECTED FROM MID MORNING MONDAY
THROUGH MONDAY AFTERNOON.

WINDS WILL INCREASE MONDAY AFTERNOON FROM THE SOUTHWEST AT 15 TO
30 KNOTS.


&&

.MARINE...
ISSUED AT 330 AM EDT MON APR 20 2015

LEFT THE HEADLINE AS IS. WINDS ARE ON THE LIGHT SIDE CURRENTLY AS
LOW PRESSURE MOVES OVER LOWER MICHIGAN. AS THE LOW MOVES FARTHER
AWAY...WINDS WILL INCREASE FROM THE SOUTHWEST AND WAVE WILL ALSO
RESPOND. A SMALL CRAFT ADVISORY MAY BE NEEDED NORTH OF WHITEHALL
TONIGHT.

&&

.HYDROLOGY...
ISSUED AT 1114 AM EDT SUN APR 19 2015

PERIODS OF RAIN ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON AND
AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. THE LIGHTER VARIETY OF
PRECIPITATION MAY EXTENT INTO MIDWEEK. THOUGH WE WILL SEE A DECENT
SOIL
SOAKING IT SHOULD NOT BE SUBSTANTIAL ENOUGH TO CREATE FLOODING
CONCERNS. GRADUAL BUT MINOR RISES ARE LIKELY...SUSPECTING THAT
THIS WOULD STAY WITHIN BANKS FOR MOST LOCATIONS. I WOULD NOT RULE
OUT A COUPLE OF SITES FLIRTING WITH ADVISORY STAGE AS WE GO INTO
TUESDAY...ESPECIALLY IF ANY MODERATE RAINFALL IS MORE PERSISTENT
WITH THE FIRST COUPLE OF ROUNDS OF MOISTURE. OTHERWISE...AREA
RIVERS ARE WELL BEHAVED THROUGH THE PERIOD.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...DUKE
HYDROLOGY...JAM
MARINE...04









000
FXUS63 KMQT 200716
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
316 AM EDT MON APR 20 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT MON APR 20 2015

UPPER AIR PATTERN CONSISTS OF A ELONGATED 500 MB TROUGH WITH SEVERAL
SHORTWAVES EMBEDDED IN IT. THE SHORTWAVE OVER LOWER MICHIGAN WILL BE
SPREADING PCPN UP INTO THE CWA THIS MORNING WHILE ANOTHER SHORTWAVE
OVER THE RED RIVER VALLEY OF THE NORTH WILL PUT PCPN IN OVER THE FAR
WEST THIS MORNING. BOTH THESE SHORTWAVES WILL COMBINE OVER THE AREA
AND CAUSE SOME WIDESPREAD PCPN THIS MORNING OVER THE CWA. UPPER
TROUGH SLOWLY MOVES EAST WITH A 500 MB LOW MOVING OVER THE U.P. LATE
TONIGHT. NAM SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE OVER THE CWA THIS MORNING. THE DEEPER MOISTURE REMAIN
OVER THE AREA THROUGH TONIGHT WHILE THE Q-VECTOR CONVERGENCE WEAKENS
AND MOVES OUT BY THIS EVENING BEFORE MOVING BACK IN LATE TONIGHT
WITH THE 500 MB LOW. GFS AND ECMWF SHOW ABOUT THE SAME THING AS
WELL.

HAD TO HANG ONTO THE DRIER AIR ACROSS THE CENTRAL CWA A BIT LONGER
THIS MORNING AND CUT THE QPF AMOUNTS BECAUSE OF THIS. DID GO WITH A
COMBO OF WET BULB HEIGHTS AND WARM TEMPERATURES ALOFT TO DETERMINE
SNOW FOR THIS FORECAST AND LOOKS LIKE THE ACCUMULATING SNOW WILL BE
TONIGHT WHERE UP TO 2 INCHES COULD FALL ACROSS THE WESTERN
HIGHLANDS. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
TEMPERATURE FORECAST AND WENT WITH CATEGORICAL POPS FOR TODAY FOR
THE CWA AND THEN LIKELY POPS IN NORTHWEST LAKE EFFECT BELTS TONIGHT
AND KEPT SOME SLIGHT CHANCE POPS IN THE FAR SOUTH DUE TO THE UPPER
LOW MOVING INTO THE AREA AND WRAPAROUND PCPN IN THE AREA.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 423 PM EDT SUN APR 19 2015

THE PATTERN WILL BE DOMINATED BY A MID/UPPER LEVEL LOW MOVING SLOWLY
THROUGH THE GREAT LAKES BRINGING UNSETTLED WEATHER ALONG WITH BELOW
NORMAL TEMPERATURES. THE LOW SHOULD FINALLY SHIFT TOWARD ERN CANADA
AND NEW ENGLAND BY THE WEEKEND LEAVING NW FLOW IN PLACE WITH
CONTINUED BELOW NORMAL TEMPERATURES.

MON NIGHT THROUGH TUE NIGHT...MODELS SUGGEST THAT THE MID LEVEL LOW
WILL SLOWLY WOBBLE INTO THE NRN GREAT LAKES. WITH THE COMBINATION OF
DEEP MOISTURE AND WEAK SHORTWAVES NEAR THE LOW...EXPECT INCREASING
PCPN CHANCES AS MAINLY SNOW...PER FCST SOUNDINGS. THERE MAY BE SOME
ADDITIONAL LAKE ENHANCED (850 MB TEMPS DROP TO AROUND -8C) INTO THE
HIGHER TERRAIN OVER THE WEST WITH UPSLOPE WNW FLOW. SNOW
ACCUMULATIONS OF A FEW INCHES ARE POSSIBLE...MAINLY ON GRASSY
SURFACES. HOWEVER...WITH THE ARRIVAL OF THE SNOW OVERNIGHT SOME
ACCUMULATION ON ROADS MAY ALSO CREATE HAZARDOUS TRAVEL TUE MORNING.
DAYTIME HEATING TUE MAY ENHANCE THE PCPN OVER INLAND AREAS WITH STEEP
SFC-700MB LAPSE RATES DEVELOPING. WITH TEMPS CLIMBING TO AROUND
40F...THE PCPN MAY MIX WITH RAIN OVER THE SE HALF OF THE CWA. 12Z NAM
FCST WET-BULB ZERO HEIGHTS WERE USED TO DELINEATE PCPN TYPE. ANOTHER
INCH OR TWO OF SNOW WILL BE POSSIBLE MAINLY OVER THE NW WIND
SNOWBELTS IN THE WEST TUE NIGHT AS 850 MB TEMPS DROP TO AROUND -12C
WHILE THE DEEP MOISTURE AND LOW LEVEL CYCLONIC FLOW REMAIN IN PLACE.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN SOUTH DURING
PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE CONTRIBUTION AS 850
MB TEMPS RANGE FROM -10C TO -13C...THE BEST COVERAGE DURING THE
DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM LAKE SUPERIOR WHERE
HEATING WILL BE STRONGEST. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW
NORMAL...IN THE MID 30S TO LOWER 40S...WARMEST S CNTRL.

FRI-SUN...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH ONLY MINIMAL PCPN CHANCES.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 106 AM EDT MON APR 20 2015

LOW PRES OVER SW MI WILL LIFT N TODAY WHILE A LOW PRES TROF MOVES E
AND MERGES WITH THE LOW. THESE 2 FEATURES WILL SPREAD SHRA ACROSS
THE AREA OVERNIGHT...BRINGING DETERIORATING CONDITIONS.

SFC TROF HAS ALREADY PASSED KIWD. WITH RAIN OVER THE COLD LAKE
WATERS AND AN UPSLOPE NW WIND...LIFR CONDITIONS WILL LIKELY PREVAIL
THRU THE MORNING HRS. THE -SHRA WILL MIX WITH OR CHANGE TO -SHSN
AROUND MID MORNING. PCPN WILL THEN DIMINISH IN THE AFTN WITH
CONDITIONS IMPROVING TO MVFR UNDER GUSTY WNW WINDS. MIGHT EVEN SEE A
PERIOD OF VFR CONDITIONS. ANOTHER DISTURBANCE MAY BRING
DETERIORATING CONDITIONS AGAIN LATE THIS EVENING.

AT KCMX...WITH MAIN AREA OF PCPN AND SFC TROF NOT ARRIVING UNTIL
AROUND DAYBREAK...VFR CONDITIONS SHOULD PREVAIL UNTIL AROUND 10Z.
EXPECT A QUICK DROP TO LIFR DURING THE MORNING UNDER INCREASING
UPSLOPE NW WINDS...THEN ONLY GRADUAL IMPROVEMENT TO IFR IN THE AFTN
AS -SHRA CONTINUE. NW WIND WILL LIKELY GUST TO AROUND 30KT DURING
THE AFTN.

AT KSAW...UNTIL ARRIVAL OF SHRA FROM THE S...VFR CONDITIONS WILL
PREVAIL FOR THE NEXT FEW HRS. ARRIVAL OF SHRA AND WINDS BACKING
AROUND TO AN UPSLOPE NE TO N DIRECTION OFF LAKE SUPERIOR WILL RESULT
IN CONDITIONS QUICKLY FALLING TO LIFR BEFORE 12Z. AS WINDS BACK TO
THE NW AND THEN W IN THE AFTN AND PCPN DIMINISHES...EXPECT
IMPROVEMENT TO MVFR. MIGHT EVEN SEE A PERIOD OF VFR LATE AFTN/EARLY
EVENING.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT MON APR 20 2015

AS A LOW LIFTS THROUGH THE SOO THIS AFTERNOON...WINDS WILL BACK TO
THE WEST-NORTHWEST THIS AFTERNOON. WITH THE LOW BECOMING STATIONARY
JUST TO THE SOUTHWEST OF JAMES BAY TONIGHT THROUGH
WEDNESDAY...PERSISTENT NORTHWESTERLY WINDS OF 20-30KTS ARE EXPECTED.
ALTHOUGH THE LOW WILL WEAKEN AND MOVE EAST ACROSS QUEBEC WEDNESDAY
NIGHT INTO THURSDAY...THE NORTHWEST WINDS UP TO 25KTS WILL PERSIST
AS A RIDGE MOVES INTO THE NORTHERN PLAINS. THE WINDS DIMINISH THEN
BELOW 20 KNOTS BY THURSDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...JLB
AVIATION...ROLFSON
MARINE...07




000
FXUS63 KMQT 200716
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
316 AM EDT MON APR 20 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT MON APR 20 2015

UPPER AIR PATTERN CONSISTS OF A ELONGATED 500 MB TROUGH WITH SEVERAL
SHORTWAVES EMBEDDED IN IT. THE SHORTWAVE OVER LOWER MICHIGAN WILL BE
SPREADING PCPN UP INTO THE CWA THIS MORNING WHILE ANOTHER SHORTWAVE
OVER THE RED RIVER VALLEY OF THE NORTH WILL PUT PCPN IN OVER THE FAR
WEST THIS MORNING. BOTH THESE SHORTWAVES WILL COMBINE OVER THE AREA
AND CAUSE SOME WIDESPREAD PCPN THIS MORNING OVER THE CWA. UPPER
TROUGH SLOWLY MOVES EAST WITH A 500 MB LOW MOVING OVER THE U.P. LATE
TONIGHT. NAM SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE OVER THE CWA THIS MORNING. THE DEEPER MOISTURE REMAIN
OVER THE AREA THROUGH TONIGHT WHILE THE Q-VECTOR CONVERGENCE WEAKENS
AND MOVES OUT BY THIS EVENING BEFORE MOVING BACK IN LATE TONIGHT
WITH THE 500 MB LOW. GFS AND ECMWF SHOW ABOUT THE SAME THING AS
WELL.

HAD TO HANG ONTO THE DRIER AIR ACROSS THE CENTRAL CWA A BIT LONGER
THIS MORNING AND CUT THE QPF AMOUNTS BECAUSE OF THIS. DID GO WITH A
COMBO OF WET BULB HEIGHTS AND WARM TEMPERATURES ALOFT TO DETERMINE
SNOW FOR THIS FORECAST AND LOOKS LIKE THE ACCUMULATING SNOW WILL BE
TONIGHT WHERE UP TO 2 INCHES COULD FALL ACROSS THE WESTERN
HIGHLANDS. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
TEMPERATURE FORECAST AND WENT WITH CATEGORICAL POPS FOR TODAY FOR
THE CWA AND THEN LIKELY POPS IN NORTHWEST LAKE EFFECT BELTS TONIGHT
AND KEPT SOME SLIGHT CHANCE POPS IN THE FAR SOUTH DUE TO THE UPPER
LOW MOVING INTO THE AREA AND WRAPAROUND PCPN IN THE AREA.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 423 PM EDT SUN APR 19 2015

THE PATTERN WILL BE DOMINATED BY A MID/UPPER LEVEL LOW MOVING SLOWLY
THROUGH THE GREAT LAKES BRINGING UNSETTLED WEATHER ALONG WITH BELOW
NORMAL TEMPERATURES. THE LOW SHOULD FINALLY SHIFT TOWARD ERN CANADA
AND NEW ENGLAND BY THE WEEKEND LEAVING NW FLOW IN PLACE WITH
CONTINUED BELOW NORMAL TEMPERATURES.

MON NIGHT THROUGH TUE NIGHT...MODELS SUGGEST THAT THE MID LEVEL LOW
WILL SLOWLY WOBBLE INTO THE NRN GREAT LAKES. WITH THE COMBINATION OF
DEEP MOISTURE AND WEAK SHORTWAVES NEAR THE LOW...EXPECT INCREASING
PCPN CHANCES AS MAINLY SNOW...PER FCST SOUNDINGS. THERE MAY BE SOME
ADDITIONAL LAKE ENHANCED (850 MB TEMPS DROP TO AROUND -8C) INTO THE
HIGHER TERRAIN OVER THE WEST WITH UPSLOPE WNW FLOW. SNOW
ACCUMULATIONS OF A FEW INCHES ARE POSSIBLE...MAINLY ON GRASSY
SURFACES. HOWEVER...WITH THE ARRIVAL OF THE SNOW OVERNIGHT SOME
ACCUMULATION ON ROADS MAY ALSO CREATE HAZARDOUS TRAVEL TUE MORNING.
DAYTIME HEATING TUE MAY ENHANCE THE PCPN OVER INLAND AREAS WITH STEEP
SFC-700MB LAPSE RATES DEVELOPING. WITH TEMPS CLIMBING TO AROUND
40F...THE PCPN MAY MIX WITH RAIN OVER THE SE HALF OF THE CWA. 12Z NAM
FCST WET-BULB ZERO HEIGHTS WERE USED TO DELINEATE PCPN TYPE. ANOTHER
INCH OR TWO OF SNOW WILL BE POSSIBLE MAINLY OVER THE NW WIND
SNOWBELTS IN THE WEST TUE NIGHT AS 850 MB TEMPS DROP TO AROUND -12C
WHILE THE DEEP MOISTURE AND LOW LEVEL CYCLONIC FLOW REMAIN IN PLACE.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN SOUTH DURING
PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE CONTRIBUTION AS 850
MB TEMPS RANGE FROM -10C TO -13C...THE BEST COVERAGE DURING THE
DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM LAKE SUPERIOR WHERE
HEATING WILL BE STRONGEST. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW
NORMAL...IN THE MID 30S TO LOWER 40S...WARMEST S CNTRL.

FRI-SUN...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH ONLY MINIMAL PCPN CHANCES.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 106 AM EDT MON APR 20 2015

LOW PRES OVER SW MI WILL LIFT N TODAY WHILE A LOW PRES TROF MOVES E
AND MERGES WITH THE LOW. THESE 2 FEATURES WILL SPREAD SHRA ACROSS
THE AREA OVERNIGHT...BRINGING DETERIORATING CONDITIONS.

SFC TROF HAS ALREADY PASSED KIWD. WITH RAIN OVER THE COLD LAKE
WATERS AND AN UPSLOPE NW WIND...LIFR CONDITIONS WILL LIKELY PREVAIL
THRU THE MORNING HRS. THE -SHRA WILL MIX WITH OR CHANGE TO -SHSN
AROUND MID MORNING. PCPN WILL THEN DIMINISH IN THE AFTN WITH
CONDITIONS IMPROVING TO MVFR UNDER GUSTY WNW WINDS. MIGHT EVEN SEE A
PERIOD OF VFR CONDITIONS. ANOTHER DISTURBANCE MAY BRING
DETERIORATING CONDITIONS AGAIN LATE THIS EVENING.

AT KCMX...WITH MAIN AREA OF PCPN AND SFC TROF NOT ARRIVING UNTIL
AROUND DAYBREAK...VFR CONDITIONS SHOULD PREVAIL UNTIL AROUND 10Z.
EXPECT A QUICK DROP TO LIFR DURING THE MORNING UNDER INCREASING
UPSLOPE NW WINDS...THEN ONLY GRADUAL IMPROVEMENT TO IFR IN THE AFTN
AS -SHRA CONTINUE. NW WIND WILL LIKELY GUST TO AROUND 30KT DURING
THE AFTN.

AT KSAW...UNTIL ARRIVAL OF SHRA FROM THE S...VFR CONDITIONS WILL
PREVAIL FOR THE NEXT FEW HRS. ARRIVAL OF SHRA AND WINDS BACKING
AROUND TO AN UPSLOPE NE TO N DIRECTION OFF LAKE SUPERIOR WILL RESULT
IN CONDITIONS QUICKLY FALLING TO LIFR BEFORE 12Z. AS WINDS BACK TO
THE NW AND THEN W IN THE AFTN AND PCPN DIMINISHES...EXPECT
IMPROVEMENT TO MVFR. MIGHT EVEN SEE A PERIOD OF VFR LATE AFTN/EARLY
EVENING.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT MON APR 20 2015

AS A LOW LIFTS THROUGH THE SOO THIS AFTERNOON...WINDS WILL BACK TO
THE WEST-NORTHWEST THIS AFTERNOON. WITH THE LOW BECOMING STATIONARY
JUST TO THE SOUTHWEST OF JAMES BAY TONIGHT THROUGH
WEDNESDAY...PERSISTENT NORTHWESTERLY WINDS OF 20-30KTS ARE EXPECTED.
ALTHOUGH THE LOW WILL WEAKEN AND MOVE EAST ACROSS QUEBEC WEDNESDAY
NIGHT INTO THURSDAY...THE NORTHWEST WINDS UP TO 25KTS WILL PERSIST
AS A RIDGE MOVES INTO THE NORTHERN PLAINS. THE WINDS DIMINISH THEN
BELOW 20 KNOTS BY THURSDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...JLB
AVIATION...ROLFSON
MARINE...07



000
FXUS63 KMQT 200716
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
316 AM EDT MON APR 20 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT MON APR 20 2015

UPPER AIR PATTERN CONSISTS OF A ELONGATED 500 MB TROUGH WITH SEVERAL
SHORTWAVES EMBEDDED IN IT. THE SHORTWAVE OVER LOWER MICHIGAN WILL BE
SPREADING PCPN UP INTO THE CWA THIS MORNING WHILE ANOTHER SHORTWAVE
OVER THE RED RIVER VALLEY OF THE NORTH WILL PUT PCPN IN OVER THE FAR
WEST THIS MORNING. BOTH THESE SHORTWAVES WILL COMBINE OVER THE AREA
AND CAUSE SOME WIDESPREAD PCPN THIS MORNING OVER THE CWA. UPPER
TROUGH SLOWLY MOVES EAST WITH A 500 MB LOW MOVING OVER THE U.P. LATE
TONIGHT. NAM SHOWS DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE OVER THE CWA THIS MORNING. THE DEEPER MOISTURE REMAIN
OVER THE AREA THROUGH TONIGHT WHILE THE Q-VECTOR CONVERGENCE WEAKENS
AND MOVES OUT BY THIS EVENING BEFORE MOVING BACK IN LATE TONIGHT
WITH THE 500 MB LOW. GFS AND ECMWF SHOW ABOUT THE SAME THING AS
WELL.

HAD TO HANG ONTO THE DRIER AIR ACROSS THE CENTRAL CWA A BIT LONGER
THIS MORNING AND CUT THE QPF AMOUNTS BECAUSE OF THIS. DID GO WITH A
COMBO OF WET BULB HEIGHTS AND WARM TEMPERATURES ALOFT TO DETERMINE
SNOW FOR THIS FORECAST AND LOOKS LIKE THE ACCUMULATING SNOW WILL BE
TONIGHT WHERE UP TO 2 INCHES COULD FALL ACROSS THE WESTERN
HIGHLANDS. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING
TEMPERATURE FORECAST AND WENT WITH CATEGORICAL POPS FOR TODAY FOR
THE CWA AND THEN LIKELY POPS IN NORTHWEST LAKE EFFECT BELTS TONIGHT
AND KEPT SOME SLIGHT CHANCE POPS IN THE FAR SOUTH DUE TO THE UPPER
LOW MOVING INTO THE AREA AND WRAPAROUND PCPN IN THE AREA.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 423 PM EDT SUN APR 19 2015

THE PATTERN WILL BE DOMINATED BY A MID/UPPER LEVEL LOW MOVING SLOWLY
THROUGH THE GREAT LAKES BRINGING UNSETTLED WEATHER ALONG WITH BELOW
NORMAL TEMPERATURES. THE LOW SHOULD FINALLY SHIFT TOWARD ERN CANADA
AND NEW ENGLAND BY THE WEEKEND LEAVING NW FLOW IN PLACE WITH
CONTINUED BELOW NORMAL TEMPERATURES.

MON NIGHT THROUGH TUE NIGHT...MODELS SUGGEST THAT THE MID LEVEL LOW
WILL SLOWLY WOBBLE INTO THE NRN GREAT LAKES. WITH THE COMBINATION OF
DEEP MOISTURE AND WEAK SHORTWAVES NEAR THE LOW...EXPECT INCREASING
PCPN CHANCES AS MAINLY SNOW...PER FCST SOUNDINGS. THERE MAY BE SOME
ADDITIONAL LAKE ENHANCED (850 MB TEMPS DROP TO AROUND -8C) INTO THE
HIGHER TERRAIN OVER THE WEST WITH UPSLOPE WNW FLOW. SNOW
ACCUMULATIONS OF A FEW INCHES ARE POSSIBLE...MAINLY ON GRASSY
SURFACES. HOWEVER...WITH THE ARRIVAL OF THE SNOW OVERNIGHT SOME
ACCUMULATION ON ROADS MAY ALSO CREATE HAZARDOUS TRAVEL TUE MORNING.
DAYTIME HEATING TUE MAY ENHANCE THE PCPN OVER INLAND AREAS WITH STEEP
SFC-700MB LAPSE RATES DEVELOPING. WITH TEMPS CLIMBING TO AROUND
40F...THE PCPN MAY MIX WITH RAIN OVER THE SE HALF OF THE CWA. 12Z NAM
FCST WET-BULB ZERO HEIGHTS WERE USED TO DELINEATE PCPN TYPE. ANOTHER
INCH OR TWO OF SNOW WILL BE POSSIBLE MAINLY OVER THE NW WIND
SNOWBELTS IN THE WEST TUE NIGHT AS 850 MB TEMPS DROP TO AROUND -12C
WHILE THE DEEP MOISTURE AND LOW LEVEL CYCLONIC FLOW REMAIN IN PLACE.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN SOUTH DURING
PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE CONTRIBUTION AS 850
MB TEMPS RANGE FROM -10C TO -13C...THE BEST COVERAGE DURING THE
DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM LAKE SUPERIOR WHERE
HEATING WILL BE STRONGEST. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW
NORMAL...IN THE MID 30S TO LOWER 40S...WARMEST S CNTRL.

FRI-SUN...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH ONLY MINIMAL PCPN CHANCES.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 106 AM EDT MON APR 20 2015

LOW PRES OVER SW MI WILL LIFT N TODAY WHILE A LOW PRES TROF MOVES E
AND MERGES WITH THE LOW. THESE 2 FEATURES WILL SPREAD SHRA ACROSS
THE AREA OVERNIGHT...BRINGING DETERIORATING CONDITIONS.

SFC TROF HAS ALREADY PASSED KIWD. WITH RAIN OVER THE COLD LAKE
WATERS AND AN UPSLOPE NW WIND...LIFR CONDITIONS WILL LIKELY PREVAIL
THRU THE MORNING HRS. THE -SHRA WILL MIX WITH OR CHANGE TO -SHSN
AROUND MID MORNING. PCPN WILL THEN DIMINISH IN THE AFTN WITH
CONDITIONS IMPROVING TO MVFR UNDER GUSTY WNW WINDS. MIGHT EVEN SEE A
PERIOD OF VFR CONDITIONS. ANOTHER DISTURBANCE MAY BRING
DETERIORATING CONDITIONS AGAIN LATE THIS EVENING.

AT KCMX...WITH MAIN AREA OF PCPN AND SFC TROF NOT ARRIVING UNTIL
AROUND DAYBREAK...VFR CONDITIONS SHOULD PREVAIL UNTIL AROUND 10Z.
EXPECT A QUICK DROP TO LIFR DURING THE MORNING UNDER INCREASING
UPSLOPE NW WINDS...THEN ONLY GRADUAL IMPROVEMENT TO IFR IN THE AFTN
AS -SHRA CONTINUE. NW WIND WILL LIKELY GUST TO AROUND 30KT DURING
THE AFTN.

AT KSAW...UNTIL ARRIVAL OF SHRA FROM THE S...VFR CONDITIONS WILL
PREVAIL FOR THE NEXT FEW HRS. ARRIVAL OF SHRA AND WINDS BACKING
AROUND TO AN UPSLOPE NE TO N DIRECTION OFF LAKE SUPERIOR WILL RESULT
IN CONDITIONS QUICKLY FALLING TO LIFR BEFORE 12Z. AS WINDS BACK TO
THE NW AND THEN W IN THE AFTN AND PCPN DIMINISHES...EXPECT
IMPROVEMENT TO MVFR. MIGHT EVEN SEE A PERIOD OF VFR LATE AFTN/EARLY
EVENING.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT MON APR 20 2015

AS A LOW LIFTS THROUGH THE SOO THIS AFTERNOON...WINDS WILL BACK TO
THE WEST-NORTHWEST THIS AFTERNOON. WITH THE LOW BECOMING STATIONARY
JUST TO THE SOUTHWEST OF JAMES BAY TONIGHT THROUGH
WEDNESDAY...PERSISTENT NORTHWESTERLY WINDS OF 20-30KTS ARE EXPECTED.
ALTHOUGH THE LOW WILL WEAKEN AND MOVE EAST ACROSS QUEBEC WEDNESDAY
NIGHT INTO THURSDAY...THE NORTHWEST WINDS UP TO 25KTS WILL PERSIST
AS A RIDGE MOVES INTO THE NORTHERN PLAINS. THE WINDS DIMINISH THEN
BELOW 20 KNOTS BY THURSDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...JLB
AVIATION...ROLFSON
MARINE...07




000
FXUS63 KAPX 200645
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
245 AM EDT MON APR 20 2015

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 245 AM EDT MON APR 20 2015

LOW PRESSURE CENTER HAS REACHED FAR SW LWR MICHIGAN EARLY THIS
MORNING. WIDESPREAD RAIN NORTH OF THE LOW CENTER HAS SPREAD ACROSS
OUR ENTIRE CWA...WITH ADDITIONAL WIDESPREAD RAIN SHOWER ACTIVITY
EXPANDING AROUND AND EAST OF THE LOW CENTER THANKS TO STRONG 700-500
MB OMEGA AND DEEP MOISTURE CONTINUING TO ADVECT INTO THE REGION.
BOTH THE LATEST NAM AND ECMWF SUGGEST THERE WILL BE A BRIEF DIMINISH
IN POP DURING LATE MORNING/EARLY AFTERNOON AS THE LOW CENTER REACHES
ERN UPR MICHIGAN. DEEP MOISTURE THEN QUICKLY WRAPS BACK INTO
MICHIGAN AS THE LOW CONTINUES NORTHWARD INTO CANADA BY LATE
AFTERNOON. WILL CERTAINLY KEEP CATEGORICAL POPS IN PLACE THRU EARLY
MORNING...WITH ONLY A MINOR DIMINISH IN POPS TO LIKELY ACROSS OUR
SRN CWA THRU THE DAY. ALL THUNDER CHANCES WILL STAY WELL SOUTH OF
MICHIGAN ALONG AND AHEAD OF THE ASSOCIATED WARM FRONT. TEMPS WILL BE
NOTICEABLY COOLER TODAY...WITH HIGH TEMPS RANGING FROM THE MID 40S
IN ERN UPR MICHIGAN TO THE UPPER 50S IN NE LWR MICHIGAN.

SRN EDGE OF WRAP AROUND MOISTURE WILL ALSO LIFT NORTHWARD AS THE
SURFACE LOW DEPARTS DEEP INTO CANADA TONIGHT. HIGHEST POPS (LIKELY)
WILL RESIDE ACROSS THE NRN TWO-THIRDS OF OUR CWA DURING THE EVENING
WHERE LIFT AND WRAP-AROUND MOISTURE WILL LINGER THE LONGEST. ALL
POPS WILL DIMINISH TO CHANCE OVERNIGHT. COLD AIR WRAPPING AROUND THE
DEPARTING LOW WILL DROP 850 MB TEMPS TO AROUND -3 TO -4 C TONIGHT.
WHILE THIS WILL NOT BE SUFFICIENTLY COLD (YET) TO ACTIVATE THE LAKES
TO PROVIDE LAKE ENHANCEMENT TO ONGOING SYNOPTIC PRECIP...BUT IT WILL
BE COLD ENOUGH TO BEGIN TO MIX SOME SNOW IN WITH THE ONGOING RAIN
EVENT DURING THE OVERNIGHT HOURS. EXPECT NO SNOW ACCUMULATION AS
SURFACE TEMPS BOTTOM OUT AT OR A FEW DEGREES ABOVE FREEZING.

&&

.SHORT TERM...(TUESDAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 245 AM EDT MON APR 20 2015

HIGH IMPACT WEATHER POTENTIAL: NOTHING SIGNIFICANT.

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: UNFORTUNATELY...NOW MUCH
TALKED ABOUT CHANGES TO A COOLER WEATHER REGIME ALREADY UNFOLDING AT
THIS EARLY HOUR...WITH ROBUST WEST NOAM RIDGE AMPLIFICATION AND
STRONG SHORTWAVE DIVING ON ITS FRONT SIDE INTO THE NORTHERN PLAINS.
THIS LATTER FEATURE WILL HELP CARVE OUT DEVELOPMENT OF ONE RATHER
IMPRESSIVE UPPER LEVEL LOW ACROSS THE FAR NORTHERN LAKES THROUGH THE
MIDDLE OF THE WEEK...WITH THE FORMER HELPING NEGATE ANY REAL KICKER
SYSTEM TO HELP BOOT THIS SYSTEM OUT. THIS SPELLS A RATHER PROLONGED
PERIOD OF COOL AND DAMP WEATHER...WITH SEVERAL OPPORTUNITIES TO SEE
A LEAST A LITTLE BIT OF SNOW BY THE TIME THIS WORK WEEK WRAPS UP
(QUELL THE EXCITEMENT :)).

PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE TRENDS
AND ADDRESSING PERIODIC PRECIP CHANCES AND TYPE.

DETAILS: CENTER OF UPPER LEVEL COLD CORE GYRE EXPECTED TO SLOWLY
MAKE ITS WAY EAST ACROSS LAKE SUPERIOR TO START THE SHORT TERM
PERIOD (TUESDAY)...ESSENTIALLY STALLING OUT JUST TO OUR NORTH RIGHT
THROUGH WEDNESDAY NIGHT. WHILE AT NO TIMES DOES FORCING SEEM
GREAT...SPOKES OF SUPPORT ROTATING AROUND PARENT SYSTEM COMBINING
WITH DEEP CYCLONIC MOISTURE RICH FLOW AND STEEP LOW/MID LEVEL LAPSE
RATES (H5 TEMPS STILL SLATED TO FLIRT WITH -30C) WILL DEFINITELY
SUPPORT THE THREAT FOR SHOWERS TUESDAY THROUGH WEDNESDAY NIGHT.
GIVEN LACK OF ANY DEEP LAYER TRIGGER...WOULD EXPECT GREATEST SHOWER
COVERAGE TO OCCUR DURING THE LATE MORNING/AFTERNOON HOURS WHEN LOW
LEVEL LAPSE RATES ARE MAXIMIZED. STILL HINTS OVER-RIDING AIRMASS MAY
BECOME JUST COLD ENOUGH TO ENTICE AT LEAST SOME MINOR LAKE
CONTRIBUTION LATE TUESDAY NIGHT INTO WEDNESDAY NIGHT. REAL MARGINAL
DELTA T/S (JUST FLIRTING WITH 13C) SHOULD NEGATE ANY SIGNIFICANT
RESPONSE...ALTHOUGH GOTTA ADMIT SUCH PERSISTENT WEST FLOW UP INTO
THE HIGHLANDS DOES RAISE AN EYEBROW OR TWO. INCREASINGLY COLD OFF
THE DECK THERMAL PROFILES AND STEEP LAPSE RATES DEFINITELY SUPPORTS
SNOW AND GRAUPEL MIXING IN WITH THE SHOWERS DURING THE DAYTIME HOURS
TUESDAY AND WEDNESDAY...WITH THE REAL POSSIBILITY ANY HEAVIER
SHOWERS WILL FALL AS MAINLY SNOW. OVERNIGHT PROFILES CONTINUE TO
SUPPORT MORE OF AN ALL SNOW ENVIRONMENT AS SURFACE BASED MELTING
LAYER IS NEARLY/COMPLETELY LOST. NOT EXPECTING ANY SIGNIFICANT
ACCUMULATIONS...ALTHOUGH WOULD NOT BE SURPRISED FOR THE GROUND TO
TURN WHITE BY WEDNESDAY MORNING (AN INCH OR SO)...ESPECIALLY WHERE
PERSISTENT UPSLOPE FLOW IS REALIZED INTO NORTHWEST LOWER.

AFTER THIS PAST WEEKS PLEASANT WEATHER...JUST GONNA FEEL DOWNRIGHT
CHILLY THROUGH MIDWEEK...WITH HIGHS BACK DOWN INTO THE UPPER 30S/40S
(COLDEST WEDNESDAY) AND OVERNIGHT LOWS A GOOD 10 OR SO DEGREES
COLDER. GUSTY WINDS AND DAMP CONDITIONS WILL ONLY ADD CONSIDERABLE
MORE CHILL. SOUNDS FUN...DOESN`T IT?

&&

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 245 AM EDT MON APR 20 2015

STILL SOME DISCREPANCIES
REGARDING JUST HOW LONG THIS SYSTEM LINGERS INTO THE END OF THE
WEEK...WITH THE GFS/GEFS/GEM NOTABLY SLOWER MOVING IT OUT THAN
RECENT ECMWF/UKMET RUNS. GIVEN UNCERTAINTIES...WILL SIMPLY RIDE WITH
INHERITED FORECAST...FEATURING SOME LINGERING LIGHT RAIN/SNOW
SHOWERS (AT LEAST FOR PARTS OF THE AREA) RIGHT THROUGH
FRIDAY...GIVING WAY TO A DRY WEEKEND. NO MATTER HOW FAST THIS SYSTEM
EXITS...AIRMASS RECOVERY WILL BE A SLOW ONE...SUGGESTING
TEMPERATURES REMAINING BELOW NORMAL RIGHT THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 100 AM EDT MON APR 20 2015

MAINLY MVFR CONDITIONS ARE EXPECTED AT ALL NRN LWR MICHIGAN TAF
SITES THRU 00Z TUESDAY AS WIDESPREAD RAIN SHOWERS CONTINUE TO
IMPACT THE REGION. CONDITIONS MAY BRIEFLY DROP TO IFR THRU EARLY
MORNING WITHIN HEAVIER RAIN SHOWERS. RAIN SHOWERS WILL BECOME
SCATTERED AFTER 00Z TUESDAY...WITH OVERALL CONDITIONS RETURNING TO
VFR...ALBEIT LOW VFR. EAST WINDS GUSTING TO 20 KTS THRU EARLY
MORNING WILL SHIFT TO THE W/SW BY AFTERNOON.

&&

.MARINE...
ISSUED AT 245 AM EDT MON APR 20 2015

SCA CRITERIA WILL CONTINUE TO BE MET ACROSS MOST OF OUR NEARSHORE
AREAS THRU THIS AFTERNOON AS DEEP LOW PRESSURE LIFTS NORTHWARD
THRU MICHIGAN. EAST WINDS WILL SHIFT TO THE SW BY AROUND MIDDAY AS
THE SURFACE LOW BEGINS TO PULL NORTH OF MICHIGAN...SHIFTING THE
FOCUS OF THE STRONGEST WINDS AND BIGGEST WAVES FROM THE LAKE
HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
     LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
     LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
     LSZ321-322.

&&

$$

NEAR TERM...MLR
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...MLR
MARINE...MLR




000
FXUS63 KAPX 200645
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
245 AM EDT MON APR 20 2015

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 245 AM EDT MON APR 20 2015

LOW PRESSURE CENTER HAS REACHED FAR SW LWR MICHIGAN EARLY THIS
MORNING. WIDESPREAD RAIN NORTH OF THE LOW CENTER HAS SPREAD ACROSS
OUR ENTIRE CWA...WITH ADDITIONAL WIDESPREAD RAIN SHOWER ACTIVITY
EXPANDING AROUND AND EAST OF THE LOW CENTER THANKS TO STRONG 700-500
MB OMEGA AND DEEP MOISTURE CONTINUING TO ADVECT INTO THE REGION.
BOTH THE LATEST NAM AND ECMWF SUGGEST THERE WILL BE A BRIEF DIMINISH
IN POP DURING LATE MORNING/EARLY AFTERNOON AS THE LOW CENTER REACHES
ERN UPR MICHIGAN. DEEP MOISTURE THEN QUICKLY WRAPS BACK INTO
MICHIGAN AS THE LOW CONTINUES NORTHWARD INTO CANADA BY LATE
AFTERNOON. WILL CERTAINLY KEEP CATEGORICAL POPS IN PLACE THRU EARLY
MORNING...WITH ONLY A MINOR DIMINISH IN POPS TO LIKELY ACROSS OUR
SRN CWA THRU THE DAY. ALL THUNDER CHANCES WILL STAY WELL SOUTH OF
MICHIGAN ALONG AND AHEAD OF THE ASSOCIATED WARM FRONT. TEMPS WILL BE
NOTICEABLY COOLER TODAY...WITH HIGH TEMPS RANGING FROM THE MID 40S
IN ERN UPR MICHIGAN TO THE UPPER 50S IN NE LWR MICHIGAN.

SRN EDGE OF WRAP AROUND MOISTURE WILL ALSO LIFT NORTHWARD AS THE
SURFACE LOW DEPARTS DEEP INTO CANADA TONIGHT. HIGHEST POPS (LIKELY)
WILL RESIDE ACROSS THE NRN TWO-THIRDS OF OUR CWA DURING THE EVENING
WHERE LIFT AND WRAP-AROUND MOISTURE WILL LINGER THE LONGEST. ALL
POPS WILL DIMINISH TO CHANCE OVERNIGHT. COLD AIR WRAPPING AROUND THE
DEPARTING LOW WILL DROP 850 MB TEMPS TO AROUND -3 TO -4 C TONIGHT.
WHILE THIS WILL NOT BE SUFFICIENTLY COLD (YET) TO ACTIVATE THE LAKES
TO PROVIDE LAKE ENHANCEMENT TO ONGOING SYNOPTIC PRECIP...BUT IT WILL
BE COLD ENOUGH TO BEGIN TO MIX SOME SNOW IN WITH THE ONGOING RAIN
EVENT DURING THE OVERNIGHT HOURS. EXPECT NO SNOW ACCUMULATION AS
SURFACE TEMPS BOTTOM OUT AT OR A FEW DEGREES ABOVE FREEZING.

&&

.SHORT TERM...(TUESDAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 245 AM EDT MON APR 20 2015

HIGH IMPACT WEATHER POTENTIAL: NOTHING SIGNIFICANT.

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: UNFORTUNATELY...NOW MUCH
TALKED ABOUT CHANGES TO A COOLER WEATHER REGIME ALREADY UNFOLDING AT
THIS EARLY HOUR...WITH ROBUST WEST NOAM RIDGE AMPLIFICATION AND
STRONG SHORTWAVE DIVING ON ITS FRONT SIDE INTO THE NORTHERN PLAINS.
THIS LATTER FEATURE WILL HELP CARVE OUT DEVELOPMENT OF ONE RATHER
IMPRESSIVE UPPER LEVEL LOW ACROSS THE FAR NORTHERN LAKES THROUGH THE
MIDDLE OF THE WEEK...WITH THE FORMER HELPING NEGATE ANY REAL KICKER
SYSTEM TO HELP BOOT THIS SYSTEM OUT. THIS SPELLS A RATHER PROLONGED
PERIOD OF COOL AND DAMP WEATHER...WITH SEVERAL OPPORTUNITIES TO SEE
A LEAST A LITTLE BIT OF SNOW BY THE TIME THIS WORK WEEK WRAPS UP
(QUELL THE EXCITEMENT :)).

PRIMARY FORECAST CONCERNS/CHALLENGES: TEMPERATURE TRENDS
AND ADDRESSING PERIODIC PRECIP CHANCES AND TYPE.

DETAILS: CENTER OF UPPER LEVEL COLD CORE GYRE EXPECTED TO SLOWLY
MAKE ITS WAY EAST ACROSS LAKE SUPERIOR TO START THE SHORT TERM
PERIOD (TUESDAY)...ESSENTIALLY STALLING OUT JUST TO OUR NORTH RIGHT
THROUGH WEDNESDAY NIGHT. WHILE AT NO TIMES DOES FORCING SEEM
GREAT...SPOKES OF SUPPORT ROTATING AROUND PARENT SYSTEM COMBINING
WITH DEEP CYCLONIC MOISTURE RICH FLOW AND STEEP LOW/MID LEVEL LAPSE
RATES (H5 TEMPS STILL SLATED TO FLIRT WITH -30C) WILL DEFINITELY
SUPPORT THE THREAT FOR SHOWERS TUESDAY THROUGH WEDNESDAY NIGHT.
GIVEN LACK OF ANY DEEP LAYER TRIGGER...WOULD EXPECT GREATEST SHOWER
COVERAGE TO OCCUR DURING THE LATE MORNING/AFTERNOON HOURS WHEN LOW
LEVEL LAPSE RATES ARE MAXIMIZED. STILL HINTS OVER-RIDING AIRMASS MAY
BECOME JUST COLD ENOUGH TO ENTICE AT LEAST SOME MINOR LAKE
CONTRIBUTION LATE TUESDAY NIGHT INTO WEDNESDAY NIGHT. REAL MARGINAL
DELTA T/S (JUST FLIRTING WITH 13C) SHOULD NEGATE ANY SIGNIFICANT
RESPONSE...ALTHOUGH GOTTA ADMIT SUCH PERSISTENT WEST FLOW UP INTO
THE HIGHLANDS DOES RAISE AN EYEBROW OR TWO. INCREASINGLY COLD OFF
THE DECK THERMAL PROFILES AND STEEP LAPSE RATES DEFINITELY SUPPORTS
SNOW AND GRAUPEL MIXING IN WITH THE SHOWERS DURING THE DAYTIME HOURS
TUESDAY AND WEDNESDAY...WITH THE REAL POSSIBILITY ANY HEAVIER
SHOWERS WILL FALL AS MAINLY SNOW. OVERNIGHT PROFILES CONTINUE TO
SUPPORT MORE OF AN ALL SNOW ENVIRONMENT AS SURFACE BASED MELTING
LAYER IS NEARLY/COMPLETELY LOST. NOT EXPECTING ANY SIGNIFICANT
ACCUMULATIONS...ALTHOUGH WOULD NOT BE SURPRISED FOR THE GROUND TO
TURN WHITE BY WEDNESDAY MORNING (AN INCH OR SO)...ESPECIALLY WHERE
PERSISTENT UPSLOPE FLOW IS REALIZED INTO NORTHWEST LOWER.

AFTER THIS PAST WEEKS PLEASANT WEATHER...JUST GONNA FEEL DOWNRIGHT
CHILLY THROUGH MIDWEEK...WITH HIGHS BACK DOWN INTO THE UPPER 30S/40S
(COLDEST WEDNESDAY) AND OVERNIGHT LOWS A GOOD 10 OR SO DEGREES
COLDER. GUSTY WINDS AND DAMP CONDITIONS WILL ONLY ADD CONSIDERABLE
MORE CHILL. SOUNDS FUN...DOESN`T IT?

&&

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 245 AM EDT MON APR 20 2015

STILL SOME DISCREPANCIES
REGARDING JUST HOW LONG THIS SYSTEM LINGERS INTO THE END OF THE
WEEK...WITH THE GFS/GEFS/GEM NOTABLY SLOWER MOVING IT OUT THAN
RECENT ECMWF/UKMET RUNS. GIVEN UNCERTAINTIES...WILL SIMPLY RIDE WITH
INHERITED FORECAST...FEATURING SOME LINGERING LIGHT RAIN/SNOW
SHOWERS (AT LEAST FOR PARTS OF THE AREA) RIGHT THROUGH
FRIDAY...GIVING WAY TO A DRY WEEKEND. NO MATTER HOW FAST THIS SYSTEM
EXITS...AIRMASS RECOVERY WILL BE A SLOW ONE...SUGGESTING
TEMPERATURES REMAINING BELOW NORMAL RIGHT THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 100 AM EDT MON APR 20 2015

MAINLY MVFR CONDITIONS ARE EXPECTED AT ALL NRN LWR MICHIGAN TAF
SITES THRU 00Z TUESDAY AS WIDESPREAD RAIN SHOWERS CONTINUE TO
IMPACT THE REGION. CONDITIONS MAY BRIEFLY DROP TO IFR THRU EARLY
MORNING WITHIN HEAVIER RAIN SHOWERS. RAIN SHOWERS WILL BECOME
SCATTERED AFTER 00Z TUESDAY...WITH OVERALL CONDITIONS RETURNING TO
VFR...ALBEIT LOW VFR. EAST WINDS GUSTING TO 20 KTS THRU EARLY
MORNING WILL SHIFT TO THE W/SW BY AFTERNOON.

&&

.MARINE...
ISSUED AT 245 AM EDT MON APR 20 2015

SCA CRITERIA WILL CONTINUE TO BE MET ACROSS MOST OF OUR NEARSHORE
AREAS THRU THIS AFTERNOON AS DEEP LOW PRESSURE LIFTS NORTHWARD
THRU MICHIGAN. EAST WINDS WILL SHIFT TO THE SW BY AROUND MIDDAY AS
THE SURFACE LOW BEGINS TO PULL NORTH OF MICHIGAN...SHIFTING THE
FOCUS OF THE STRONGEST WINDS AND BIGGEST WAVES FROM THE LAKE
HURON SHORELINE TO THE LAKE MICHIGAN SHORELINE.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
     LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
     LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
     LSZ321-322.

&&

$$

NEAR TERM...MLR
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...MLR
MARINE...MLR



000
FXUS63 KMQT 200506
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
106 AM EDT MON APR 20 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

TWO UPPER LEVEL WAVES WILL BE AFFECTING THE REGION TONIGHT BEFORE
MERGING TOGETHER INTO A LARGE UPPER TROUGH THAT WILL PERSIST OVER
EASTERN CANADA AND THE GREAT LAKES REGION FOR MUCH OF THE UPCOMING
WORK WEEK. THIS WILL LEAD TO A TRANSITION FROM THE ABOVE NORMAL
TEMPERATURES AND DRY CONDITIONS TO A PERIOD OF BELOW NORMAL
TEMPERATURES AND PERIODS OF RAIN/SNOW SHOWERS.

THE FIRST WAVE OF PRECIPITATION JUST BRUSHED THE WESTERN U.P.
EARLIER TODAY...ASSOCIATED WITH A SHORTWAVE AND MID LEVEL WARM AIR
ADVECTION. MUCH OF THAT PRECIPITATION HAS SHIFTED OFF TO THE NORTH
OF THE MINNESOTA ARROWHEAD...BUT LINGERING MID LEVEL MOISTURE AND
BROAD BUT WEAK WARM AIR ADVECTION HAS PRODUCED A FEW RAIN SHOWERS
OVER WESTERN/CENTRAL UPPER MICHIGAN LATE THIS MORNING AND THROUGH
THE EARLY AFTERNOON. WHILE THE 12Z KGRB SOUNDING STILL SHOWS SOME
DRY AIR BELOW THE CLOUD BASES...IT HAS ERODED SIGNIFICANTLY SINCE
THE 00Z KGRB SOUNDING AND ALLOWED SOME OF THAT RAIN TO REACH THE
GROUND. THAT DISTURBANCE PRODUCING THE SHOWERS WILL SHIFT TO THE
NORTH OVER THE NEXT COUPLE OF HOURS AND SHIFT THE FOCUS TO THE RAIN
CURRENTLY TO THE WEST AND SOUTH OF THE CWA.

WITH THE LATEST TRENDS IN THE MODELS DELAYING THE ARRIVAL OF THE
PRECIPITATION FROM THE SOUTH (ASSOCIATED WITH THE SOUTHERN WAVE AND
SURFACE LOW QUICKLY LIFTING NORTH ACROSS THE SOO MONDAY MORNING)
UNTIL LATE IN THE EVENING AND MORE DURING THE OVERNIGHT HOURS...HAVE
CONTINUED TO SHOW THAT SLOWING TREND IN THE POPS FOR THIS EVENING.
IN FACT...OTHER THAN SOME CHANCES OVER THE FAR WEST THIS
EVENING...HAVE REMOVED THE POPS OVER THE CENTRAL EAST BETWEEN THE
23Z-03Z PERIOD AND THEN RAMPED THEM UP AS THAT WAVE AND LOW ARRIVES
FROM THE SOUTH. THAT PRECIPITATION WILL THEN QUICKLY SHIFT NORTH
ACROSS THE AREA AND EXPECT MUCH OF THE CENTRAL/EASTERN U.P. TO SEE
AT LEAST 0.3 INCH OF RAIN. THERE WILL BE SOME HIGHER
AMOUNTS...LIKELY 0.5-0.6IN WHERE THE DEFORMATION ZONE OCCURS ON THE
NORTHWEST SIDE OF THE SURFACE LOW (SOMEWHERE AROUND THE CENTRAL OR
WEST-CENTRAL U.P.). FARTHER TO THE WEST...EXPECT THE ONGOING RAIN
SHOWERS STRETCHING FROM THE ARROWHEAD OF MINNESOTA THROUGH WESTERN
WISCONSIN AND INTO NORTHEAST IOWA TO SLOWLY SHIFT EAST INTO FAR
WESTERN UPPER MICHIGAN THIS EVENING...AS THE 850-700MB TROUGH SLOWLY
WORKS ITS WAY TO THE EAST. THIS PRECIPITATION WILL MERGE WITH THE
WAVE COMING UP FROM THE SOUTH AND FILL IN THE EXPECTED GAP OVER THE
KEWEENAW OVERNIGHT.

WITH THE SHORTWAVE AND SURFACE LOW QUICKLY MOVING TO THE NORTH ON
MONDAY...EXPECT THE PRECIPITATION TO DIMINISH FROM SOUTHWEST TO
NORTHEAST THROUGH THE DAY (AIDED BY THE MID LEVEL DRY SLOT THAT
SLOWLY MOVES INTO THE AREA). WHILE MUCH OF THIS PRECIP WILL OCCUR AS
RAIN...THE COLD AIR GRADUALLY MOVING INTO THE WESTERN CWA LATE
TONIGHT AND MONDAY COULD CAUSE IT TO MIXING WITH OR EVEN CHANGING
OVER TO SNOW OVER THE WEST AND POSSIBLY EVEN NORTH CENTRAL. THOUGHT
THAT THE WETBULB ZERO HAD A GOOD HANDLE ON THE WEST TO EAST
TRANSITION OF THAT MIX WITH SNOW...BUT DO HAVE A CONCERN ON THE
AMOUNT OF ICE CRYSTALS THAT WILL BE PRESENT ON MONDAY. MODELS
SHOWING THAT THE DEEPER MOISTURE REALLY BEGINS TO PULL OUT THROUGH
THE DAY AS THE MID LEVEL DRY SLOT MOVES BEHIND THE 850/700MB TROUGH.
THAT CONCERN WARRANTS KEEPING RAIN POTENTIAL IN THE FORECAST EVEN
THOUGH SOME AREAS THE WETBULB ZERO VALUES WOULD SUPPORT ALL SNOW.
ONE FINAL NOTE...THE HIGHER RESOLUTION 12Z MODELS ARE SHOWING A
SLOWER DEPARTURE TO THE PRECIP ON MONDAY...SO DID TREND SLIGHTLY
SLOWER WITH THIS FORECAST AND IT MAY NEED TO BE DELAYED FURTHER WITH
THE UPCOMING SHIFT. THAT SLOWER DEPARTURE AND INDICATIONS OF COLDER
AIR...COULD LEAD TO SOME MINOR SNOW ACCUMULATIONS ON GRASSY SURFACES
OVER THE WEST AROUND MID MORNING.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 423 PM EDT SUN APR 19 2015

THE PATTERN WILL BE DOMINATED BY A MID/UPPER LEVEL LOW MOVING SLOWLY
THROUGH THE GREAT LAKES BRINGING UNSETTLED WEATHER ALONG WITH BELOW
NORMAL TEMPERATURES. THE LOW SHOULD FINALLY SHIFT TOWARD ERN CANADA
AND NEW ENGLAND BY THE WEEKEND LEAVING NW FLOW IN PLACE WITH
CONTINUED BELOW NORMAL TEMPERATURES.

MON NIGHT THROUGH TUE NIGHT...MODELS SUGGEST THAT THE MID LEVEL LOW
WILL SLOWLY WOBBLE INTO THE NRN GREAT LAKES. WITH THE COMBINATION OF
DEEP MOISTURE AND WEAK SHORTWAVES NEAR THE LOW...EXPECT INCREASING
PCPN CHANCES AS MAINLY SNOW...PER FCST SOUNDINGS. THERE MAY BE SOME
ADDITIONAL LAKE ENHANCED (850 MB TEMPS DROP TO AROUND -8C) INTO THE
HIGHER TERRAIN OVER THE WEST WITH UPSLOPE WNW FLOW. SNOW
ACCUMULATIONS OF A FEW INCHES ARE POSSIBLE...MAINLY ON GRASSY
SURFACES. HOWEVER...WITH THE ARRIVAL OF THE SNOW OVERNIGHT SOME
ACCUMULATION ON ROADS MAY ALSO CREATE HAZARDOUS TRAVEL TUE MORNING.
DAYTIME HEATING TUE MAY ENHANCE THE PCPN OVER INLAND AREAS WITH STEEP
SFC-700MB LAPSE RATES DEVELOPING. WITH TEMPS CLIMBING TO AROUND
40F...THE PCPN MAY MIX WITH RAIN OVER THE SE HALF OF THE CWA. 12Z NAM
FCST WET-BULB ZERO HEIGHTS WERE USED TO DELINEATE PCPN TYPE. ANOTHER
INCH OR TWO OF SNOW WILL BE POSSIBLE MAINLY OVER THE NW WIND
SNOWBELTS IN THE WEST TUE NIGHT AS 850 MB TEMPS DROP TO AROUND -12C
WHILE THE DEEP MOISTURE AND LOW LEVEL CYCLONIC FLOW REMAIN IN PLACE.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN SOUTH DURING
PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE CONTRIBUTION AS 850
MB TEMPS RANGE FROM -10C TO -13C...THE BEST COVERAGE DURING THE
DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM LAKE SUPERIOR WHERE
HEATING WILL BE STRONGEST. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW
NORMAL...IN THE MID 30S TO LOWER 40S...WARMEST S CNTRL.

FRI-SUN...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH ONLY MINIMAL PCPN CHANCES.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 106 AM EDT MON APR 20 2015

LOW PRES OVER SW MI WILL LIFT N TODAY WHILE A LOW PRES TROF MOVES E
AND MERGES WITH THE LOW. THESE 2 FEATURES WILL SPREAD SHRA ACROSS
THE AREA OVERNIGHT...BRINGING DETERIORATING CONDITIONS.

SFC TROF HAS ALREADY PASSED KIWD. WITH RAIN OVER THE COLD LAKE
WATERS AND AN UPSLOPE NW WIND...LIFR CONDITIONS WILL LIKELY PREVAIL
THRU THE MORNING HRS. THE -SHRA WILL MIX WITH OR CHANGE TO -SHSN
AROUND MID MORNING. PCPN WILL THEN DIMINISH IN THE AFTN WITH
CONDITIONS IMPROVING TO MVFR UNDER GUSTY WNW WINDS. MIGHT EVEN SEE A
PERIOD OF VFR CONDITIONS. ANOTHER DISTURBANCE MAY BRING
DETERIORATING CONDITIONS AGAIN LATE THIS EVENING.

AT KCMX...WITH MAIN AREA OF PCPN AND SFC TROF NOT ARRIVING UNTIL
AROUND DAYBREAK...VFR CONDITIONS SHOULD PREVAIL UNTIL AROUND 10Z.
EXPECT A QUICK DROP TO LIFR DURING THE MORNING UNDER INCREASING
UPSLOPE NW WINDS...THEN ONLY GRADUAL IMPROVEMENT TO IFR IN THE AFTN
AS -SHRA CONTINUE. NW WIND WILL LIKELY GUST TO AROUND 30KT DURING
THE AFTN.

AT KSAW...UNTIL ARRIVAL OF SHRA FROM THE S...VFR CONDITIONS WILL
PREVAIL FOR THE NEXT FEW HRS. ARRIVAL OF SHRA AND WINDS BACKING
AROUND TO AN UPSLOPE NE TO N DIRECTION OFF LAKE SUPERIOR WILL RESULT
IN CONDITIONS QUICKLY FALLING TO LIFR BEFORE 12Z. AS WINDS BACK TO
THE NW AND THEN W IN THE AFTN AND PCPN DIMINISHES...EXPECT
IMPROVEMENT TO MVFR. MIGHT EVEN SEE A PERIOD OF VFR LATE AFTN/EARLY
EVENING.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 258 PM EDT SUN APR 19 2015

SOUTHEASTERLY WINDS UP TO 25-30KTS ARE OCCURRING OVER NORTHEAST
LAKE SUPERIOR...WITH A FEW GUSTS NEARING GALE FORCE VALUES AT THE
HIGHER PLATFORMS (SHIP OBS AND PILM4). AS A LOW IN SOUTHERN ILLINOIS
LIFTS NORTH TONIGHT AND THROUGH THE SOO ON MONDAY MORNING...WINDS
WILL WEAKEN THIS EVENING AND THEN BACK TO THE WEST-NORTHWEST ON
MONDAY. WITH THE LOW BECOMING STATIONARY JUST TO THE SOUTHWEST OF
JAMES BAY MONDAY NIGHT THROUGH WEDNESDAY...PERSISTENT NORTHWESTERLY
WINDS OF 20-30KTS ARE EXPECTED. ALTHOUGH THE LOW WILL WEAKEN AND
MOVE EAST ACROSS QUEBEC WEDNESDAY NIGHT INTO THURSDAY...THE
NORTHWEST WINDS UP TO 25KTS WILL PERSIST AS A RIDGE MOVES INTO THE
NORTHERN PLAINS.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...SRF
LONG TERM...JLB
AVIATION...ROLFSON
MARINE...SRF




000
FXUS63 KMQT 200506
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
106 AM EDT MON APR 20 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

TWO UPPER LEVEL WAVES WILL BE AFFECTING THE REGION TONIGHT BEFORE
MERGING TOGETHER INTO A LARGE UPPER TROUGH THAT WILL PERSIST OVER
EASTERN CANADA AND THE GREAT LAKES REGION FOR MUCH OF THE UPCOMING
WORK WEEK. THIS WILL LEAD TO A TRANSITION FROM THE ABOVE NORMAL
TEMPERATURES AND DRY CONDITIONS TO A PERIOD OF BELOW NORMAL
TEMPERATURES AND PERIODS OF RAIN/SNOW SHOWERS.

THE FIRST WAVE OF PRECIPITATION JUST BRUSHED THE WESTERN U.P.
EARLIER TODAY...ASSOCIATED WITH A SHORTWAVE AND MID LEVEL WARM AIR
ADVECTION. MUCH OF THAT PRECIPITATION HAS SHIFTED OFF TO THE NORTH
OF THE MINNESOTA ARROWHEAD...BUT LINGERING MID LEVEL MOISTURE AND
BROAD BUT WEAK WARM AIR ADVECTION HAS PRODUCED A FEW RAIN SHOWERS
OVER WESTERN/CENTRAL UPPER MICHIGAN LATE THIS MORNING AND THROUGH
THE EARLY AFTERNOON. WHILE THE 12Z KGRB SOUNDING STILL SHOWS SOME
DRY AIR BELOW THE CLOUD BASES...IT HAS ERODED SIGNIFICANTLY SINCE
THE 00Z KGRB SOUNDING AND ALLOWED SOME OF THAT RAIN TO REACH THE
GROUND. THAT DISTURBANCE PRODUCING THE SHOWERS WILL SHIFT TO THE
NORTH OVER THE NEXT COUPLE OF HOURS AND SHIFT THE FOCUS TO THE RAIN
CURRENTLY TO THE WEST AND SOUTH OF THE CWA.

WITH THE LATEST TRENDS IN THE MODELS DELAYING THE ARRIVAL OF THE
PRECIPITATION FROM THE SOUTH (ASSOCIATED WITH THE SOUTHERN WAVE AND
SURFACE LOW QUICKLY LIFTING NORTH ACROSS THE SOO MONDAY MORNING)
UNTIL LATE IN THE EVENING AND MORE DURING THE OVERNIGHT HOURS...HAVE
CONTINUED TO SHOW THAT SLOWING TREND IN THE POPS FOR THIS EVENING.
IN FACT...OTHER THAN SOME CHANCES OVER THE FAR WEST THIS
EVENING...HAVE REMOVED THE POPS OVER THE CENTRAL EAST BETWEEN THE
23Z-03Z PERIOD AND THEN RAMPED THEM UP AS THAT WAVE AND LOW ARRIVES
FROM THE SOUTH. THAT PRECIPITATION WILL THEN QUICKLY SHIFT NORTH
ACROSS THE AREA AND EXPECT MUCH OF THE CENTRAL/EASTERN U.P. TO SEE
AT LEAST 0.3 INCH OF RAIN. THERE WILL BE SOME HIGHER
AMOUNTS...LIKELY 0.5-0.6IN WHERE THE DEFORMATION ZONE OCCURS ON THE
NORTHWEST SIDE OF THE SURFACE LOW (SOMEWHERE AROUND THE CENTRAL OR
WEST-CENTRAL U.P.). FARTHER TO THE WEST...EXPECT THE ONGOING RAIN
SHOWERS STRETCHING FROM THE ARROWHEAD OF MINNESOTA THROUGH WESTERN
WISCONSIN AND INTO NORTHEAST IOWA TO SLOWLY SHIFT EAST INTO FAR
WESTERN UPPER MICHIGAN THIS EVENING...AS THE 850-700MB TROUGH SLOWLY
WORKS ITS WAY TO THE EAST. THIS PRECIPITATION WILL MERGE WITH THE
WAVE COMING UP FROM THE SOUTH AND FILL IN THE EXPECTED GAP OVER THE
KEWEENAW OVERNIGHT.

WITH THE SHORTWAVE AND SURFACE LOW QUICKLY MOVING TO THE NORTH ON
MONDAY...EXPECT THE PRECIPITATION TO DIMINISH FROM SOUTHWEST TO
NORTHEAST THROUGH THE DAY (AIDED BY THE MID LEVEL DRY SLOT THAT
SLOWLY MOVES INTO THE AREA). WHILE MUCH OF THIS PRECIP WILL OCCUR AS
RAIN...THE COLD AIR GRADUALLY MOVING INTO THE WESTERN CWA LATE
TONIGHT AND MONDAY COULD CAUSE IT TO MIXING WITH OR EVEN CHANGING
OVER TO SNOW OVER THE WEST AND POSSIBLY EVEN NORTH CENTRAL. THOUGHT
THAT THE WETBULB ZERO HAD A GOOD HANDLE ON THE WEST TO EAST
TRANSITION OF THAT MIX WITH SNOW...BUT DO HAVE A CONCERN ON THE
AMOUNT OF ICE CRYSTALS THAT WILL BE PRESENT ON MONDAY. MODELS
SHOWING THAT THE DEEPER MOISTURE REALLY BEGINS TO PULL OUT THROUGH
THE DAY AS THE MID LEVEL DRY SLOT MOVES BEHIND THE 850/700MB TROUGH.
THAT CONCERN WARRANTS KEEPING RAIN POTENTIAL IN THE FORECAST EVEN
THOUGH SOME AREAS THE WETBULB ZERO VALUES WOULD SUPPORT ALL SNOW.
ONE FINAL NOTE...THE HIGHER RESOLUTION 12Z MODELS ARE SHOWING A
SLOWER DEPARTURE TO THE PRECIP ON MONDAY...SO DID TREND SLIGHTLY
SLOWER WITH THIS FORECAST AND IT MAY NEED TO BE DELAYED FURTHER WITH
THE UPCOMING SHIFT. THAT SLOWER DEPARTURE AND INDICATIONS OF COLDER
AIR...COULD LEAD TO SOME MINOR SNOW ACCUMULATIONS ON GRASSY SURFACES
OVER THE WEST AROUND MID MORNING.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 423 PM EDT SUN APR 19 2015

THE PATTERN WILL BE DOMINATED BY A MID/UPPER LEVEL LOW MOVING SLOWLY
THROUGH THE GREAT LAKES BRINGING UNSETTLED WEATHER ALONG WITH BELOW
NORMAL TEMPERATURES. THE LOW SHOULD FINALLY SHIFT TOWARD ERN CANADA
AND NEW ENGLAND BY THE WEEKEND LEAVING NW FLOW IN PLACE WITH
CONTINUED BELOW NORMAL TEMPERATURES.

MON NIGHT THROUGH TUE NIGHT...MODELS SUGGEST THAT THE MID LEVEL LOW
WILL SLOWLY WOBBLE INTO THE NRN GREAT LAKES. WITH THE COMBINATION OF
DEEP MOISTURE AND WEAK SHORTWAVES NEAR THE LOW...EXPECT INCREASING
PCPN CHANCES AS MAINLY SNOW...PER FCST SOUNDINGS. THERE MAY BE SOME
ADDITIONAL LAKE ENHANCED (850 MB TEMPS DROP TO AROUND -8C) INTO THE
HIGHER TERRAIN OVER THE WEST WITH UPSLOPE WNW FLOW. SNOW
ACCUMULATIONS OF A FEW INCHES ARE POSSIBLE...MAINLY ON GRASSY
SURFACES. HOWEVER...WITH THE ARRIVAL OF THE SNOW OVERNIGHT SOME
ACCUMULATION ON ROADS MAY ALSO CREATE HAZARDOUS TRAVEL TUE MORNING.
DAYTIME HEATING TUE MAY ENHANCE THE PCPN OVER INLAND AREAS WITH STEEP
SFC-700MB LAPSE RATES DEVELOPING. WITH TEMPS CLIMBING TO AROUND
40F...THE PCPN MAY MIX WITH RAIN OVER THE SE HALF OF THE CWA. 12Z NAM
FCST WET-BULB ZERO HEIGHTS WERE USED TO DELINEATE PCPN TYPE. ANOTHER
INCH OR TWO OF SNOW WILL BE POSSIBLE MAINLY OVER THE NW WIND
SNOWBELTS IN THE WEST TUE NIGHT AS 850 MB TEMPS DROP TO AROUND -12C
WHILE THE DEEP MOISTURE AND LOW LEVEL CYCLONIC FLOW REMAIN IN PLACE.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN SOUTH DURING
PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE CONTRIBUTION AS 850
MB TEMPS RANGE FROM -10C TO -13C...THE BEST COVERAGE DURING THE
DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM LAKE SUPERIOR WHERE
HEATING WILL BE STRONGEST. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW
NORMAL...IN THE MID 30S TO LOWER 40S...WARMEST S CNTRL.

FRI-SUN...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH ONLY MINIMAL PCPN CHANCES.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 106 AM EDT MON APR 20 2015

LOW PRES OVER SW MI WILL LIFT N TODAY WHILE A LOW PRES TROF MOVES E
AND MERGES WITH THE LOW. THESE 2 FEATURES WILL SPREAD SHRA ACROSS
THE AREA OVERNIGHT...BRINGING DETERIORATING CONDITIONS.

SFC TROF HAS ALREADY PASSED KIWD. WITH RAIN OVER THE COLD LAKE
WATERS AND AN UPSLOPE NW WIND...LIFR CONDITIONS WILL LIKELY PREVAIL
THRU THE MORNING HRS. THE -SHRA WILL MIX WITH OR CHANGE TO -SHSN
AROUND MID MORNING. PCPN WILL THEN DIMINISH IN THE AFTN WITH
CONDITIONS IMPROVING TO MVFR UNDER GUSTY WNW WINDS. MIGHT EVEN SEE A
PERIOD OF VFR CONDITIONS. ANOTHER DISTURBANCE MAY BRING
DETERIORATING CONDITIONS AGAIN LATE THIS EVENING.

AT KCMX...WITH MAIN AREA OF PCPN AND SFC TROF NOT ARRIVING UNTIL
AROUND DAYBREAK...VFR CONDITIONS SHOULD PREVAIL UNTIL AROUND 10Z.
EXPECT A QUICK DROP TO LIFR DURING THE MORNING UNDER INCREASING
UPSLOPE NW WINDS...THEN ONLY GRADUAL IMPROVEMENT TO IFR IN THE AFTN
AS -SHRA CONTINUE. NW WIND WILL LIKELY GUST TO AROUND 30KT DURING
THE AFTN.

AT KSAW...UNTIL ARRIVAL OF SHRA FROM THE S...VFR CONDITIONS WILL
PREVAIL FOR THE NEXT FEW HRS. ARRIVAL OF SHRA AND WINDS BACKING
AROUND TO AN UPSLOPE NE TO N DIRECTION OFF LAKE SUPERIOR WILL RESULT
IN CONDITIONS QUICKLY FALLING TO LIFR BEFORE 12Z. AS WINDS BACK TO
THE NW AND THEN W IN THE AFTN AND PCPN DIMINISHES...EXPECT
IMPROVEMENT TO MVFR. MIGHT EVEN SEE A PERIOD OF VFR LATE AFTN/EARLY
EVENING.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 258 PM EDT SUN APR 19 2015

SOUTHEASTERLY WINDS UP TO 25-30KTS ARE OCCURRING OVER NORTHEAST
LAKE SUPERIOR...WITH A FEW GUSTS NEARING GALE FORCE VALUES AT THE
HIGHER PLATFORMS (SHIP OBS AND PILM4). AS A LOW IN SOUTHERN ILLINOIS
LIFTS NORTH TONIGHT AND THROUGH THE SOO ON MONDAY MORNING...WINDS
WILL WEAKEN THIS EVENING AND THEN BACK TO THE WEST-NORTHWEST ON
MONDAY. WITH THE LOW BECOMING STATIONARY JUST TO THE SOUTHWEST OF
JAMES BAY MONDAY NIGHT THROUGH WEDNESDAY...PERSISTENT NORTHWESTERLY
WINDS OF 20-30KTS ARE EXPECTED. ALTHOUGH THE LOW WILL WEAKEN AND
MOVE EAST ACROSS QUEBEC WEDNESDAY NIGHT INTO THURSDAY...THE
NORTHWEST WINDS UP TO 25KTS WILL PERSIST AS A RIDGE MOVES INTO THE
NORTHERN PLAINS.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...SRF
LONG TERM...JLB
AVIATION...ROLFSON
MARINE...SRF




000
FXUS63 KMQT 200506
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
106 AM EDT MON APR 20 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

TWO UPPER LEVEL WAVES WILL BE AFFECTING THE REGION TONIGHT BEFORE
MERGING TOGETHER INTO A LARGE UPPER TROUGH THAT WILL PERSIST OVER
EASTERN CANADA AND THE GREAT LAKES REGION FOR MUCH OF THE UPCOMING
WORK WEEK. THIS WILL LEAD TO A TRANSITION FROM THE ABOVE NORMAL
TEMPERATURES AND DRY CONDITIONS TO A PERIOD OF BELOW NORMAL
TEMPERATURES AND PERIODS OF RAIN/SNOW SHOWERS.

THE FIRST WAVE OF PRECIPITATION JUST BRUSHED THE WESTERN U.P.
EARLIER TODAY...ASSOCIATED WITH A SHORTWAVE AND MID LEVEL WARM AIR
ADVECTION. MUCH OF THAT PRECIPITATION HAS SHIFTED OFF TO THE NORTH
OF THE MINNESOTA ARROWHEAD...BUT LINGERING MID LEVEL MOISTURE AND
BROAD BUT WEAK WARM AIR ADVECTION HAS PRODUCED A FEW RAIN SHOWERS
OVER WESTERN/CENTRAL UPPER MICHIGAN LATE THIS MORNING AND THROUGH
THE EARLY AFTERNOON. WHILE THE 12Z KGRB SOUNDING STILL SHOWS SOME
DRY AIR BELOW THE CLOUD BASES...IT HAS ERODED SIGNIFICANTLY SINCE
THE 00Z KGRB SOUNDING AND ALLOWED SOME OF THAT RAIN TO REACH THE
GROUND. THAT DISTURBANCE PRODUCING THE SHOWERS WILL SHIFT TO THE
NORTH OVER THE NEXT COUPLE OF HOURS AND SHIFT THE FOCUS TO THE RAIN
CURRENTLY TO THE WEST AND SOUTH OF THE CWA.

WITH THE LATEST TRENDS IN THE MODELS DELAYING THE ARRIVAL OF THE
PRECIPITATION FROM THE SOUTH (ASSOCIATED WITH THE SOUTHERN WAVE AND
SURFACE LOW QUICKLY LIFTING NORTH ACROSS THE SOO MONDAY MORNING)
UNTIL LATE IN THE EVENING AND MORE DURING THE OVERNIGHT HOURS...HAVE
CONTINUED TO SHOW THAT SLOWING TREND IN THE POPS FOR THIS EVENING.
IN FACT...OTHER THAN SOME CHANCES OVER THE FAR WEST THIS
EVENING...HAVE REMOVED THE POPS OVER THE CENTRAL EAST BETWEEN THE
23Z-03Z PERIOD AND THEN RAMPED THEM UP AS THAT WAVE AND LOW ARRIVES
FROM THE SOUTH. THAT PRECIPITATION WILL THEN QUICKLY SHIFT NORTH
ACROSS THE AREA AND EXPECT MUCH OF THE CENTRAL/EASTERN U.P. TO SEE
AT LEAST 0.3 INCH OF RAIN. THERE WILL BE SOME HIGHER
AMOUNTS...LIKELY 0.5-0.6IN WHERE THE DEFORMATION ZONE OCCURS ON THE
NORTHWEST SIDE OF THE SURFACE LOW (SOMEWHERE AROUND THE CENTRAL OR
WEST-CENTRAL U.P.). FARTHER TO THE WEST...EXPECT THE ONGOING RAIN
SHOWERS STRETCHING FROM THE ARROWHEAD OF MINNESOTA THROUGH WESTERN
WISCONSIN AND INTO NORTHEAST IOWA TO SLOWLY SHIFT EAST INTO FAR
WESTERN UPPER MICHIGAN THIS EVENING...AS THE 850-700MB TROUGH SLOWLY
WORKS ITS WAY TO THE EAST. THIS PRECIPITATION WILL MERGE WITH THE
WAVE COMING UP FROM THE SOUTH AND FILL IN THE EXPECTED GAP OVER THE
KEWEENAW OVERNIGHT.

WITH THE SHORTWAVE AND SURFACE LOW QUICKLY MOVING TO THE NORTH ON
MONDAY...EXPECT THE PRECIPITATION TO DIMINISH FROM SOUTHWEST TO
NORTHEAST THROUGH THE DAY (AIDED BY THE MID LEVEL DRY SLOT THAT
SLOWLY MOVES INTO THE AREA). WHILE MUCH OF THIS PRECIP WILL OCCUR AS
RAIN...THE COLD AIR GRADUALLY MOVING INTO THE WESTERN CWA LATE
TONIGHT AND MONDAY COULD CAUSE IT TO MIXING WITH OR EVEN CHANGING
OVER TO SNOW OVER THE WEST AND POSSIBLY EVEN NORTH CENTRAL. THOUGHT
THAT THE WETBULB ZERO HAD A GOOD HANDLE ON THE WEST TO EAST
TRANSITION OF THAT MIX WITH SNOW...BUT DO HAVE A CONCERN ON THE
AMOUNT OF ICE CRYSTALS THAT WILL BE PRESENT ON MONDAY. MODELS
SHOWING THAT THE DEEPER MOISTURE REALLY BEGINS TO PULL OUT THROUGH
THE DAY AS THE MID LEVEL DRY SLOT MOVES BEHIND THE 850/700MB TROUGH.
THAT CONCERN WARRANTS KEEPING RAIN POTENTIAL IN THE FORECAST EVEN
THOUGH SOME AREAS THE WETBULB ZERO VALUES WOULD SUPPORT ALL SNOW.
ONE FINAL NOTE...THE HIGHER RESOLUTION 12Z MODELS ARE SHOWING A
SLOWER DEPARTURE TO THE PRECIP ON MONDAY...SO DID TREND SLIGHTLY
SLOWER WITH THIS FORECAST AND IT MAY NEED TO BE DELAYED FURTHER WITH
THE UPCOMING SHIFT. THAT SLOWER DEPARTURE AND INDICATIONS OF COLDER
AIR...COULD LEAD TO SOME MINOR SNOW ACCUMULATIONS ON GRASSY SURFACES
OVER THE WEST AROUND MID MORNING.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 423 PM EDT SUN APR 19 2015

THE PATTERN WILL BE DOMINATED BY A MID/UPPER LEVEL LOW MOVING SLOWLY
THROUGH THE GREAT LAKES BRINGING UNSETTLED WEATHER ALONG WITH BELOW
NORMAL TEMPERATURES. THE LOW SHOULD FINALLY SHIFT TOWARD ERN CANADA
AND NEW ENGLAND BY THE WEEKEND LEAVING NW FLOW IN PLACE WITH
CONTINUED BELOW NORMAL TEMPERATURES.

MON NIGHT THROUGH TUE NIGHT...MODELS SUGGEST THAT THE MID LEVEL LOW
WILL SLOWLY WOBBLE INTO THE NRN GREAT LAKES. WITH THE COMBINATION OF
DEEP MOISTURE AND WEAK SHORTWAVES NEAR THE LOW...EXPECT INCREASING
PCPN CHANCES AS MAINLY SNOW...PER FCST SOUNDINGS. THERE MAY BE SOME
ADDITIONAL LAKE ENHANCED (850 MB TEMPS DROP TO AROUND -8C) INTO THE
HIGHER TERRAIN OVER THE WEST WITH UPSLOPE WNW FLOW. SNOW
ACCUMULATIONS OF A FEW INCHES ARE POSSIBLE...MAINLY ON GRASSY
SURFACES. HOWEVER...WITH THE ARRIVAL OF THE SNOW OVERNIGHT SOME
ACCUMULATION ON ROADS MAY ALSO CREATE HAZARDOUS TRAVEL TUE MORNING.
DAYTIME HEATING TUE MAY ENHANCE THE PCPN OVER INLAND AREAS WITH STEEP
SFC-700MB LAPSE RATES DEVELOPING. WITH TEMPS CLIMBING TO AROUND
40F...THE PCPN MAY MIX WITH RAIN OVER THE SE HALF OF THE CWA. 12Z NAM
FCST WET-BULB ZERO HEIGHTS WERE USED TO DELINEATE PCPN TYPE. ANOTHER
INCH OR TWO OF SNOW WILL BE POSSIBLE MAINLY OVER THE NW WIND
SNOWBELTS IN THE WEST TUE NIGHT AS 850 MB TEMPS DROP TO AROUND -12C
WHILE THE DEEP MOISTURE AND LOW LEVEL CYCLONIC FLOW REMAIN IN PLACE.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN SOUTH DURING
PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE CONTRIBUTION AS 850
MB TEMPS RANGE FROM -10C TO -13C...THE BEST COVERAGE DURING THE
DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM LAKE SUPERIOR WHERE
HEATING WILL BE STRONGEST. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW
NORMAL...IN THE MID 30S TO LOWER 40S...WARMEST S CNTRL.

FRI-SUN...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH ONLY MINIMAL PCPN CHANCES.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 106 AM EDT MON APR 20 2015

LOW PRES OVER SW MI WILL LIFT N TODAY WHILE A LOW PRES TROF MOVES E
AND MERGES WITH THE LOW. THESE 2 FEATURES WILL SPREAD SHRA ACROSS
THE AREA OVERNIGHT...BRINGING DETERIORATING CONDITIONS.

SFC TROF HAS ALREADY PASSED KIWD. WITH RAIN OVER THE COLD LAKE
WATERS AND AN UPSLOPE NW WIND...LIFR CONDITIONS WILL LIKELY PREVAIL
THRU THE MORNING HRS. THE -SHRA WILL MIX WITH OR CHANGE TO -SHSN
AROUND MID MORNING. PCPN WILL THEN DIMINISH IN THE AFTN WITH
CONDITIONS IMPROVING TO MVFR UNDER GUSTY WNW WINDS. MIGHT EVEN SEE A
PERIOD OF VFR CONDITIONS. ANOTHER DISTURBANCE MAY BRING
DETERIORATING CONDITIONS AGAIN LATE THIS EVENING.

AT KCMX...WITH MAIN AREA OF PCPN AND SFC TROF NOT ARRIVING UNTIL
AROUND DAYBREAK...VFR CONDITIONS SHOULD PREVAIL UNTIL AROUND 10Z.
EXPECT A QUICK DROP TO LIFR DURING THE MORNING UNDER INCREASING
UPSLOPE NW WINDS...THEN ONLY GRADUAL IMPROVEMENT TO IFR IN THE AFTN
AS -SHRA CONTINUE. NW WIND WILL LIKELY GUST TO AROUND 30KT DURING
THE AFTN.

AT KSAW...UNTIL ARRIVAL OF SHRA FROM THE S...VFR CONDITIONS WILL
PREVAIL FOR THE NEXT FEW HRS. ARRIVAL OF SHRA AND WINDS BACKING
AROUND TO AN UPSLOPE NE TO N DIRECTION OFF LAKE SUPERIOR WILL RESULT
IN CONDITIONS QUICKLY FALLING TO LIFR BEFORE 12Z. AS WINDS BACK TO
THE NW AND THEN W IN THE AFTN AND PCPN DIMINISHES...EXPECT
IMPROVEMENT TO MVFR. MIGHT EVEN SEE A PERIOD OF VFR LATE AFTN/EARLY
EVENING.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 258 PM EDT SUN APR 19 2015

SOUTHEASTERLY WINDS UP TO 25-30KTS ARE OCCURRING OVER NORTHEAST
LAKE SUPERIOR...WITH A FEW GUSTS NEARING GALE FORCE VALUES AT THE
HIGHER PLATFORMS (SHIP OBS AND PILM4). AS A LOW IN SOUTHERN ILLINOIS
LIFTS NORTH TONIGHT AND THROUGH THE SOO ON MONDAY MORNING...WINDS
WILL WEAKEN THIS EVENING AND THEN BACK TO THE WEST-NORTHWEST ON
MONDAY. WITH THE LOW BECOMING STATIONARY JUST TO THE SOUTHWEST OF
JAMES BAY MONDAY NIGHT THROUGH WEDNESDAY...PERSISTENT NORTHWESTERLY
WINDS OF 20-30KTS ARE EXPECTED. ALTHOUGH THE LOW WILL WEAKEN AND
MOVE EAST ACROSS QUEBEC WEDNESDAY NIGHT INTO THURSDAY...THE
NORTHWEST WINDS UP TO 25KTS WILL PERSIST AS A RIDGE MOVES INTO THE
NORTHERN PLAINS.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...SRF
LONG TERM...JLB
AVIATION...ROLFSON
MARINE...SRF




000
FXUS63 KMQT 200506
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
106 AM EDT MON APR 20 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

TWO UPPER LEVEL WAVES WILL BE AFFECTING THE REGION TONIGHT BEFORE
MERGING TOGETHER INTO A LARGE UPPER TROUGH THAT WILL PERSIST OVER
EASTERN CANADA AND THE GREAT LAKES REGION FOR MUCH OF THE UPCOMING
WORK WEEK. THIS WILL LEAD TO A TRANSITION FROM THE ABOVE NORMAL
TEMPERATURES AND DRY CONDITIONS TO A PERIOD OF BELOW NORMAL
TEMPERATURES AND PERIODS OF RAIN/SNOW SHOWERS.

THE FIRST WAVE OF PRECIPITATION JUST BRUSHED THE WESTERN U.P.
EARLIER TODAY...ASSOCIATED WITH A SHORTWAVE AND MID LEVEL WARM AIR
ADVECTION. MUCH OF THAT PRECIPITATION HAS SHIFTED OFF TO THE NORTH
OF THE MINNESOTA ARROWHEAD...BUT LINGERING MID LEVEL MOISTURE AND
BROAD BUT WEAK WARM AIR ADVECTION HAS PRODUCED A FEW RAIN SHOWERS
OVER WESTERN/CENTRAL UPPER MICHIGAN LATE THIS MORNING AND THROUGH
THE EARLY AFTERNOON. WHILE THE 12Z KGRB SOUNDING STILL SHOWS SOME
DRY AIR BELOW THE CLOUD BASES...IT HAS ERODED SIGNIFICANTLY SINCE
THE 00Z KGRB SOUNDING AND ALLOWED SOME OF THAT RAIN TO REACH THE
GROUND. THAT DISTURBANCE PRODUCING THE SHOWERS WILL SHIFT TO THE
NORTH OVER THE NEXT COUPLE OF HOURS AND SHIFT THE FOCUS TO THE RAIN
CURRENTLY TO THE WEST AND SOUTH OF THE CWA.

WITH THE LATEST TRENDS IN THE MODELS DELAYING THE ARRIVAL OF THE
PRECIPITATION FROM THE SOUTH (ASSOCIATED WITH THE SOUTHERN WAVE AND
SURFACE LOW QUICKLY LIFTING NORTH ACROSS THE SOO MONDAY MORNING)
UNTIL LATE IN THE EVENING AND MORE DURING THE OVERNIGHT HOURS...HAVE
CONTINUED TO SHOW THAT SLOWING TREND IN THE POPS FOR THIS EVENING.
IN FACT...OTHER THAN SOME CHANCES OVER THE FAR WEST THIS
EVENING...HAVE REMOVED THE POPS OVER THE CENTRAL EAST BETWEEN THE
23Z-03Z PERIOD AND THEN RAMPED THEM UP AS THAT WAVE AND LOW ARRIVES
FROM THE SOUTH. THAT PRECIPITATION WILL THEN QUICKLY SHIFT NORTH
ACROSS THE AREA AND EXPECT MUCH OF THE CENTRAL/EASTERN U.P. TO SEE
AT LEAST 0.3 INCH OF RAIN. THERE WILL BE SOME HIGHER
AMOUNTS...LIKELY 0.5-0.6IN WHERE THE DEFORMATION ZONE OCCURS ON THE
NORTHWEST SIDE OF THE SURFACE LOW (SOMEWHERE AROUND THE CENTRAL OR
WEST-CENTRAL U.P.). FARTHER TO THE WEST...EXPECT THE ONGOING RAIN
SHOWERS STRETCHING FROM THE ARROWHEAD OF MINNESOTA THROUGH WESTERN
WISCONSIN AND INTO NORTHEAST IOWA TO SLOWLY SHIFT EAST INTO FAR
WESTERN UPPER MICHIGAN THIS EVENING...AS THE 850-700MB TROUGH SLOWLY
WORKS ITS WAY TO THE EAST. THIS PRECIPITATION WILL MERGE WITH THE
WAVE COMING UP FROM THE SOUTH AND FILL IN THE EXPECTED GAP OVER THE
KEWEENAW OVERNIGHT.

WITH THE SHORTWAVE AND SURFACE LOW QUICKLY MOVING TO THE NORTH ON
MONDAY...EXPECT THE PRECIPITATION TO DIMINISH FROM SOUTHWEST TO
NORTHEAST THROUGH THE DAY (AIDED BY THE MID LEVEL DRY SLOT THAT
SLOWLY MOVES INTO THE AREA). WHILE MUCH OF THIS PRECIP WILL OCCUR AS
RAIN...THE COLD AIR GRADUALLY MOVING INTO THE WESTERN CWA LATE
TONIGHT AND MONDAY COULD CAUSE IT TO MIXING WITH OR EVEN CHANGING
OVER TO SNOW OVER THE WEST AND POSSIBLY EVEN NORTH CENTRAL. THOUGHT
THAT THE WETBULB ZERO HAD A GOOD HANDLE ON THE WEST TO EAST
TRANSITION OF THAT MIX WITH SNOW...BUT DO HAVE A CONCERN ON THE
AMOUNT OF ICE CRYSTALS THAT WILL BE PRESENT ON MONDAY. MODELS
SHOWING THAT THE DEEPER MOISTURE REALLY BEGINS TO PULL OUT THROUGH
THE DAY AS THE MID LEVEL DRY SLOT MOVES BEHIND THE 850/700MB TROUGH.
THAT CONCERN WARRANTS KEEPING RAIN POTENTIAL IN THE FORECAST EVEN
THOUGH SOME AREAS THE WETBULB ZERO VALUES WOULD SUPPORT ALL SNOW.
ONE FINAL NOTE...THE HIGHER RESOLUTION 12Z MODELS ARE SHOWING A
SLOWER DEPARTURE TO THE PRECIP ON MONDAY...SO DID TREND SLIGHTLY
SLOWER WITH THIS FORECAST AND IT MAY NEED TO BE DELAYED FURTHER WITH
THE UPCOMING SHIFT. THAT SLOWER DEPARTURE AND INDICATIONS OF COLDER
AIR...COULD LEAD TO SOME MINOR SNOW ACCUMULATIONS ON GRASSY SURFACES
OVER THE WEST AROUND MID MORNING.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 423 PM EDT SUN APR 19 2015

THE PATTERN WILL BE DOMINATED BY A MID/UPPER LEVEL LOW MOVING SLOWLY
THROUGH THE GREAT LAKES BRINGING UNSETTLED WEATHER ALONG WITH BELOW
NORMAL TEMPERATURES. THE LOW SHOULD FINALLY SHIFT TOWARD ERN CANADA
AND NEW ENGLAND BY THE WEEKEND LEAVING NW FLOW IN PLACE WITH
CONTINUED BELOW NORMAL TEMPERATURES.

MON NIGHT THROUGH TUE NIGHT...MODELS SUGGEST THAT THE MID LEVEL LOW
WILL SLOWLY WOBBLE INTO THE NRN GREAT LAKES. WITH THE COMBINATION OF
DEEP MOISTURE AND WEAK SHORTWAVES NEAR THE LOW...EXPECT INCREASING
PCPN CHANCES AS MAINLY SNOW...PER FCST SOUNDINGS. THERE MAY BE SOME
ADDITIONAL LAKE ENHANCED (850 MB TEMPS DROP TO AROUND -8C) INTO THE
HIGHER TERRAIN OVER THE WEST WITH UPSLOPE WNW FLOW. SNOW
ACCUMULATIONS OF A FEW INCHES ARE POSSIBLE...MAINLY ON GRASSY
SURFACES. HOWEVER...WITH THE ARRIVAL OF THE SNOW OVERNIGHT SOME
ACCUMULATION ON ROADS MAY ALSO CREATE HAZARDOUS TRAVEL TUE MORNING.
DAYTIME HEATING TUE MAY ENHANCE THE PCPN OVER INLAND AREAS WITH STEEP
SFC-700MB LAPSE RATES DEVELOPING. WITH TEMPS CLIMBING TO AROUND
40F...THE PCPN MAY MIX WITH RAIN OVER THE SE HALF OF THE CWA. 12Z NAM
FCST WET-BULB ZERO HEIGHTS WERE USED TO DELINEATE PCPN TYPE. ANOTHER
INCH OR TWO OF SNOW WILL BE POSSIBLE MAINLY OVER THE NW WIND
SNOWBELTS IN THE WEST TUE NIGHT AS 850 MB TEMPS DROP TO AROUND -12C
WHILE THE DEEP MOISTURE AND LOW LEVEL CYCLONIC FLOW REMAIN IN PLACE.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN SOUTH DURING
PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE CONTRIBUTION AS 850
MB TEMPS RANGE FROM -10C TO -13C...THE BEST COVERAGE DURING THE
DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM LAKE SUPERIOR WHERE
HEATING WILL BE STRONGEST. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW
NORMAL...IN THE MID 30S TO LOWER 40S...WARMEST S CNTRL.

FRI-SUN...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH ONLY MINIMAL PCPN CHANCES.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 106 AM EDT MON APR 20 2015

LOW PRES OVER SW MI WILL LIFT N TODAY WHILE A LOW PRES TROF MOVES E
AND MERGES WITH THE LOW. THESE 2 FEATURES WILL SPREAD SHRA ACROSS
THE AREA OVERNIGHT...BRINGING DETERIORATING CONDITIONS.

SFC TROF HAS ALREADY PASSED KIWD. WITH RAIN OVER THE COLD LAKE
WATERS AND AN UPSLOPE NW WIND...LIFR CONDITIONS WILL LIKELY PREVAIL
THRU THE MORNING HRS. THE -SHRA WILL MIX WITH OR CHANGE TO -SHSN
AROUND MID MORNING. PCPN WILL THEN DIMINISH IN THE AFTN WITH
CONDITIONS IMPROVING TO MVFR UNDER GUSTY WNW WINDS. MIGHT EVEN SEE A
PERIOD OF VFR CONDITIONS. ANOTHER DISTURBANCE MAY BRING
DETERIORATING CONDITIONS AGAIN LATE THIS EVENING.

AT KCMX...WITH MAIN AREA OF PCPN AND SFC TROF NOT ARRIVING UNTIL
AROUND DAYBREAK...VFR CONDITIONS SHOULD PREVAIL UNTIL AROUND 10Z.
EXPECT A QUICK DROP TO LIFR DURING THE MORNING UNDER INCREASING
UPSLOPE NW WINDS...THEN ONLY GRADUAL IMPROVEMENT TO IFR IN THE AFTN
AS -SHRA CONTINUE. NW WIND WILL LIKELY GUST TO AROUND 30KT DURING
THE AFTN.

AT KSAW...UNTIL ARRIVAL OF SHRA FROM THE S...VFR CONDITIONS WILL
PREVAIL FOR THE NEXT FEW HRS. ARRIVAL OF SHRA AND WINDS BACKING
AROUND TO AN UPSLOPE NE TO N DIRECTION OFF LAKE SUPERIOR WILL RESULT
IN CONDITIONS QUICKLY FALLING TO LIFR BEFORE 12Z. AS WINDS BACK TO
THE NW AND THEN W IN THE AFTN AND PCPN DIMINISHES...EXPECT
IMPROVEMENT TO MVFR. MIGHT EVEN SEE A PERIOD OF VFR LATE AFTN/EARLY
EVENING.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 258 PM EDT SUN APR 19 2015

SOUTHEASTERLY WINDS UP TO 25-30KTS ARE OCCURRING OVER NORTHEAST
LAKE SUPERIOR...WITH A FEW GUSTS NEARING GALE FORCE VALUES AT THE
HIGHER PLATFORMS (SHIP OBS AND PILM4). AS A LOW IN SOUTHERN ILLINOIS
LIFTS NORTH TONIGHT AND THROUGH THE SOO ON MONDAY MORNING...WINDS
WILL WEAKEN THIS EVENING AND THEN BACK TO THE WEST-NORTHWEST ON
MONDAY. WITH THE LOW BECOMING STATIONARY JUST TO THE SOUTHWEST OF
JAMES BAY MONDAY NIGHT THROUGH WEDNESDAY...PERSISTENT NORTHWESTERLY
WINDS OF 20-30KTS ARE EXPECTED. ALTHOUGH THE LOW WILL WEAKEN AND
MOVE EAST ACROSS QUEBEC WEDNESDAY NIGHT INTO THURSDAY...THE
NORTHWEST WINDS UP TO 25KTS WILL PERSIST AS A RIDGE MOVES INTO THE
NORTHERN PLAINS.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...SRF
LONG TERM...JLB
AVIATION...ROLFSON
MARINE...SRF




000
FXUS63 KMQT 200506
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
106 AM EDT MON APR 20 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

TWO UPPER LEVEL WAVES WILL BE AFFECTING THE REGION TONIGHT BEFORE
MERGING TOGETHER INTO A LARGE UPPER TROUGH THAT WILL PERSIST OVER
EASTERN CANADA AND THE GREAT LAKES REGION FOR MUCH OF THE UPCOMING
WORK WEEK. THIS WILL LEAD TO A TRANSITION FROM THE ABOVE NORMAL
TEMPERATURES AND DRY CONDITIONS TO A PERIOD OF BELOW NORMAL
TEMPERATURES AND PERIODS OF RAIN/SNOW SHOWERS.

THE FIRST WAVE OF PRECIPITATION JUST BRUSHED THE WESTERN U.P.
EARLIER TODAY...ASSOCIATED WITH A SHORTWAVE AND MID LEVEL WARM AIR
ADVECTION. MUCH OF THAT PRECIPITATION HAS SHIFTED OFF TO THE NORTH
OF THE MINNESOTA ARROWHEAD...BUT LINGERING MID LEVEL MOISTURE AND
BROAD BUT WEAK WARM AIR ADVECTION HAS PRODUCED A FEW RAIN SHOWERS
OVER WESTERN/CENTRAL UPPER MICHIGAN LATE THIS MORNING AND THROUGH
THE EARLY AFTERNOON. WHILE THE 12Z KGRB SOUNDING STILL SHOWS SOME
DRY AIR BELOW THE CLOUD BASES...IT HAS ERODED SIGNIFICANTLY SINCE
THE 00Z KGRB SOUNDING AND ALLOWED SOME OF THAT RAIN TO REACH THE
GROUND. THAT DISTURBANCE PRODUCING THE SHOWERS WILL SHIFT TO THE
NORTH OVER THE NEXT COUPLE OF HOURS AND SHIFT THE FOCUS TO THE RAIN
CURRENTLY TO THE WEST AND SOUTH OF THE CWA.

WITH THE LATEST TRENDS IN THE MODELS DELAYING THE ARRIVAL OF THE
PRECIPITATION FROM THE SOUTH (ASSOCIATED WITH THE SOUTHERN WAVE AND
SURFACE LOW QUICKLY LIFTING NORTH ACROSS THE SOO MONDAY MORNING)
UNTIL LATE IN THE EVENING AND MORE DURING THE OVERNIGHT HOURS...HAVE
CONTINUED TO SHOW THAT SLOWING TREND IN THE POPS FOR THIS EVENING.
IN FACT...OTHER THAN SOME CHANCES OVER THE FAR WEST THIS
EVENING...HAVE REMOVED THE POPS OVER THE CENTRAL EAST BETWEEN THE
23Z-03Z PERIOD AND THEN RAMPED THEM UP AS THAT WAVE AND LOW ARRIVES
FROM THE SOUTH. THAT PRECIPITATION WILL THEN QUICKLY SHIFT NORTH
ACROSS THE AREA AND EXPECT MUCH OF THE CENTRAL/EASTERN U.P. TO SEE
AT LEAST 0.3 INCH OF RAIN. THERE WILL BE SOME HIGHER
AMOUNTS...LIKELY 0.5-0.6IN WHERE THE DEFORMATION ZONE OCCURS ON THE
NORTHWEST SIDE OF THE SURFACE LOW (SOMEWHERE AROUND THE CENTRAL OR
WEST-CENTRAL U.P.). FARTHER TO THE WEST...EXPECT THE ONGOING RAIN
SHOWERS STRETCHING FROM THE ARROWHEAD OF MINNESOTA THROUGH WESTERN
WISCONSIN AND INTO NORTHEAST IOWA TO SLOWLY SHIFT EAST INTO FAR
WESTERN UPPER MICHIGAN THIS EVENING...AS THE 850-700MB TROUGH SLOWLY
WORKS ITS WAY TO THE EAST. THIS PRECIPITATION WILL MERGE WITH THE
WAVE COMING UP FROM THE SOUTH AND FILL IN THE EXPECTED GAP OVER THE
KEWEENAW OVERNIGHT.

WITH THE SHORTWAVE AND SURFACE LOW QUICKLY MOVING TO THE NORTH ON
MONDAY...EXPECT THE PRECIPITATION TO DIMINISH FROM SOUTHWEST TO
NORTHEAST THROUGH THE DAY (AIDED BY THE MID LEVEL DRY SLOT THAT
SLOWLY MOVES INTO THE AREA). WHILE MUCH OF THIS PRECIP WILL OCCUR AS
RAIN...THE COLD AIR GRADUALLY MOVING INTO THE WESTERN CWA LATE
TONIGHT AND MONDAY COULD CAUSE IT TO MIXING WITH OR EVEN CHANGING
OVER TO SNOW OVER THE WEST AND POSSIBLY EVEN NORTH CENTRAL. THOUGHT
THAT THE WETBULB ZERO HAD A GOOD HANDLE ON THE WEST TO EAST
TRANSITION OF THAT MIX WITH SNOW...BUT DO HAVE A CONCERN ON THE
AMOUNT OF ICE CRYSTALS THAT WILL BE PRESENT ON MONDAY. MODELS
SHOWING THAT THE DEEPER MOISTURE REALLY BEGINS TO PULL OUT THROUGH
THE DAY AS THE MID LEVEL DRY SLOT MOVES BEHIND THE 850/700MB TROUGH.
THAT CONCERN WARRANTS KEEPING RAIN POTENTIAL IN THE FORECAST EVEN
THOUGH SOME AREAS THE WETBULB ZERO VALUES WOULD SUPPORT ALL SNOW.
ONE FINAL NOTE...THE HIGHER RESOLUTION 12Z MODELS ARE SHOWING A
SLOWER DEPARTURE TO THE PRECIP ON MONDAY...SO DID TREND SLIGHTLY
SLOWER WITH THIS FORECAST AND IT MAY NEED TO BE DELAYED FURTHER WITH
THE UPCOMING SHIFT. THAT SLOWER DEPARTURE AND INDICATIONS OF COLDER
AIR...COULD LEAD TO SOME MINOR SNOW ACCUMULATIONS ON GRASSY SURFACES
OVER THE WEST AROUND MID MORNING.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 423 PM EDT SUN APR 19 2015

THE PATTERN WILL BE DOMINATED BY A MID/UPPER LEVEL LOW MOVING SLOWLY
THROUGH THE GREAT LAKES BRINGING UNSETTLED WEATHER ALONG WITH BELOW
NORMAL TEMPERATURES. THE LOW SHOULD FINALLY SHIFT TOWARD ERN CANADA
AND NEW ENGLAND BY THE WEEKEND LEAVING NW FLOW IN PLACE WITH
CONTINUED BELOW NORMAL TEMPERATURES.

MON NIGHT THROUGH TUE NIGHT...MODELS SUGGEST THAT THE MID LEVEL LOW
WILL SLOWLY WOBBLE INTO THE NRN GREAT LAKES. WITH THE COMBINATION OF
DEEP MOISTURE AND WEAK SHORTWAVES NEAR THE LOW...EXPECT INCREASING
PCPN CHANCES AS MAINLY SNOW...PER FCST SOUNDINGS. THERE MAY BE SOME
ADDITIONAL LAKE ENHANCED (850 MB TEMPS DROP TO AROUND -8C) INTO THE
HIGHER TERRAIN OVER THE WEST WITH UPSLOPE WNW FLOW. SNOW
ACCUMULATIONS OF A FEW INCHES ARE POSSIBLE...MAINLY ON GRASSY
SURFACES. HOWEVER...WITH THE ARRIVAL OF THE SNOW OVERNIGHT SOME
ACCUMULATION ON ROADS MAY ALSO CREATE HAZARDOUS TRAVEL TUE MORNING.
DAYTIME HEATING TUE MAY ENHANCE THE PCPN OVER INLAND AREAS WITH STEEP
SFC-700MB LAPSE RATES DEVELOPING. WITH TEMPS CLIMBING TO AROUND
40F...THE PCPN MAY MIX WITH RAIN OVER THE SE HALF OF THE CWA. 12Z NAM
FCST WET-BULB ZERO HEIGHTS WERE USED TO DELINEATE PCPN TYPE. ANOTHER
INCH OR TWO OF SNOW WILL BE POSSIBLE MAINLY OVER THE NW WIND
SNOWBELTS IN THE WEST TUE NIGHT AS 850 MB TEMPS DROP TO AROUND -12C
WHILE THE DEEP MOISTURE AND LOW LEVEL CYCLONIC FLOW REMAIN IN PLACE.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN SOUTH DURING
PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE CONTRIBUTION AS 850
MB TEMPS RANGE FROM -10C TO -13C...THE BEST COVERAGE DURING THE
DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM LAKE SUPERIOR WHERE
HEATING WILL BE STRONGEST. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW
NORMAL...IN THE MID 30S TO LOWER 40S...WARMEST S CNTRL.

FRI-SUN...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH ONLY MINIMAL PCPN CHANCES.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 106 AM EDT MON APR 20 2015

LOW PRES OVER SW MI WILL LIFT N TODAY WHILE A LOW PRES TROF MOVES E
AND MERGES WITH THE LOW. THESE 2 FEATURES WILL SPREAD SHRA ACROSS
THE AREA OVERNIGHT...BRINGING DETERIORATING CONDITIONS.

SFC TROF HAS ALREADY PASSED KIWD. WITH RAIN OVER THE COLD LAKE
WATERS AND AN UPSLOPE NW WIND...LIFR CONDITIONS WILL LIKELY PREVAIL
THRU THE MORNING HRS. THE -SHRA WILL MIX WITH OR CHANGE TO -SHSN
AROUND MID MORNING. PCPN WILL THEN DIMINISH IN THE AFTN WITH
CONDITIONS IMPROVING TO MVFR UNDER GUSTY WNW WINDS. MIGHT EVEN SEE A
PERIOD OF VFR CONDITIONS. ANOTHER DISTURBANCE MAY BRING
DETERIORATING CONDITIONS AGAIN LATE THIS EVENING.

AT KCMX...WITH MAIN AREA OF PCPN AND SFC TROF NOT ARRIVING UNTIL
AROUND DAYBREAK...VFR CONDITIONS SHOULD PREVAIL UNTIL AROUND 10Z.
EXPECT A QUICK DROP TO LIFR DURING THE MORNING UNDER INCREASING
UPSLOPE NW WINDS...THEN ONLY GRADUAL IMPROVEMENT TO IFR IN THE AFTN
AS -SHRA CONTINUE. NW WIND WILL LIKELY GUST TO AROUND 30KT DURING
THE AFTN.

AT KSAW...UNTIL ARRIVAL OF SHRA FROM THE S...VFR CONDITIONS WILL
PREVAIL FOR THE NEXT FEW HRS. ARRIVAL OF SHRA AND WINDS BACKING
AROUND TO AN UPSLOPE NE TO N DIRECTION OFF LAKE SUPERIOR WILL RESULT
IN CONDITIONS QUICKLY FALLING TO LIFR BEFORE 12Z. AS WINDS BACK TO
THE NW AND THEN W IN THE AFTN AND PCPN DIMINISHES...EXPECT
IMPROVEMENT TO MVFR. MIGHT EVEN SEE A PERIOD OF VFR LATE AFTN/EARLY
EVENING.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 258 PM EDT SUN APR 19 2015

SOUTHEASTERLY WINDS UP TO 25-30KTS ARE OCCURRING OVER NORTHEAST
LAKE SUPERIOR...WITH A FEW GUSTS NEARING GALE FORCE VALUES AT THE
HIGHER PLATFORMS (SHIP OBS AND PILM4). AS A LOW IN SOUTHERN ILLINOIS
LIFTS NORTH TONIGHT AND THROUGH THE SOO ON MONDAY MORNING...WINDS
WILL WEAKEN THIS EVENING AND THEN BACK TO THE WEST-NORTHWEST ON
MONDAY. WITH THE LOW BECOMING STATIONARY JUST TO THE SOUTHWEST OF
JAMES BAY MONDAY NIGHT THROUGH WEDNESDAY...PERSISTENT NORTHWESTERLY
WINDS OF 20-30KTS ARE EXPECTED. ALTHOUGH THE LOW WILL WEAKEN AND
MOVE EAST ACROSS QUEBEC WEDNESDAY NIGHT INTO THURSDAY...THE
NORTHWEST WINDS UP TO 25KTS WILL PERSIST AS A RIDGE MOVES INTO THE
NORTHERN PLAINS.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...SRF
LONG TERM...JLB
AVIATION...ROLFSON
MARINE...SRF




000
FXUS63 KAPX 200500
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
100 AM EDT MON APR 20 2015

.UPDATE...
ISSUED AT 935 PM EDT SUN APR 19 2015

IT HAS BEEN IN NO HURRY...BUT WIDESPREAD RAIN IS MAKING STEADY
INROADS NORTHWARD ACROSS CENTRAL LOWER MI. LEADING EDGE IS NOW A
BIT NORTH OF GLADWIN/STANDISH. AHEAD OF THIS...A BAND OF -SHRA
HAS ADVANCED TO A FRANKFORT-GLR-PRESQUE ISLE LT LINE. HAVE BEEN
ADJUSTING TIMING OF PRECIP ONSET...MAINLY TO SLOW THINGS DOWN A
BIT. BUT THE MAIN GIST OF THE FORECAST...I.E. EVERYONE EVENTUALLY
GETS WET TONIGHT...IS FINE.

&&

.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 402 PM EDT SUN APR 19 2015

HIGH IMPACT WEATHER: MINIMAL

FORECAST CHALLENGE: TIMING OF THE RAIN TONIGHT.

OVERVIEW...WHILE THE MOISTURE HAS BEEN INCREASING ALONG THE LAKE
HURON SHORE AND INLAND OF NE LOWER, NW LOWER HAS BEEN DRYING OUT
WITH A GOOD PORTION OF THE AREA WEST OF I-75 HAVING FALLEN BELOW
25%. IN E UPPER, THE RH HAS BEEN BETWEEN 40% AND 45%. WHAT THIS IS
DOING IS DELAYING THE RAIN SHIELD`S TRAVEL NORTH, WHICH HAD JUST
MADE IT TO THE MICHIGAN/INDIANA BORDER AROUND 19Z. USING THE TIMING
TOOL ON AWIPS, IT LOOKS LIKE THE RAIN SHOULD GET TO THE M-55
CORRIDOR AROUND 23Z, M-72 AROUND 00Z, M-32 AROUND 01Z, AND THE
STRAIT BETWEEN 02Z AND 03Z.

DETAILS FOR TONIGHT...AS WAS MENTIONED, TRYING TO TIME THIS SYSTEM
WITH THE DRY AIR IN THE LOWER LEVELS IS MADDENING. THE QUESTION
ISN`T IF THE AIR WILL LEAVE, BUT WHEN AS THE SFC LOW WILL, AS IT
MOVES UP FROM THE MID-MISSISSIPPI VALLEY, OVERWHELM WITH DRY AIR
WITH ITS MOISTURE, AND ALLOW THE RAIN TO FALL ALL THE WAY TO THE
SFC. HOWEVER, ONCE THE RAIN STARTS, IT WILL FALL THROUGH THE NIGHT
AS THE SFC NORTH OVER THE WESTERN PART OF THE STATE BETWEEN 06Z AND
12Z. THIS SFC LOW AND ASSOCIATED 500 MB SHORTWAVE TROUGH AND 50 KNOT
SPEED MAX THAT MOVES OVER THE STATE, OVER THE WARM FRONT. WITH THE
PWAT AROUND 1.0" OVERNIGHT OVER THE FORECAST AREA, WILL EXPECT
THAT A DECENT STEADY RAIN WILL RESULT.

&&

.SHORT TERM...(MONDAY THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

...SHOWERY/COOL/UNSETTLED THROUGH MIDWEEK...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: WELL-DEFINED SPLIT FLOW PATTERN FROM THE
END OF LAST WEEK NOW CONSOLIDATING AS NORTHERN BRANCH SHORT WAVE
TROUGH DIGS SOUTHEAST FROM WESTERN CANADA AND SCOOPS UP PESKY
SOUTHERN BRANCH VORTEX THAT HAS BEEN SPINNING ACROSS THE GREAT
BASIN/SOUTHERN ROCKIES SINCE THE MIDDLE OF LAST WEEK.  POSITIVE
PACIFIC TELECONNECTIONS LEADING TO A MORE AMPLIFIED PATTERN (BIG
TROUGH EAST OF THE DATELINE WITH +PNA RIDGING ALONG THE WEST COAST
OF NORTH AMERICA.  THIS CONSOLIDATING CENTRAL NORTH AMERICAN TROUGH
WILL BECOME THE PREDOMINANT WEATHER FEATURE THIS WEEK AS IT TAKES UP
RESIDENCE WITH REX BLOCKING ALONG THE WEST COAST...WITH AN UPPER LOW
EVENTUALLY PARKING ITSELF OVER THE GREAT LAKES BY MIDWEEK.

SOUTHERN BRANCH DISTURBANCE LOOKS TO COME OUT IN TWO PIECES
MONDAY...WHILE CLOSED CIRCULATION ALOFT DEVELOPS OVER NORTHWEST
ONTARIO/UPPER MIDWEST.  UPPER LOW THEN SETTLES OVER LAKE SUPERIOR
TUESDAY AND HANGS IN THROUGH MIDWEEK.  AT THE SURFACE...LEAD
SOUTHERN BRANCH SHORT WAVE TROUGH HAS AN ASSOCIATED SURFACE LOW OVER
THE MID MISSISSIPPI VALLEY THAT IS FORECAST TO DEEPEN AND LIFT NORTH
INTO LOWER MICHIGAN BY MONDAY MORNING...PROBABLY BELOW 990MB WHICH
IS PRETTY SIGNIFICANT BY MID-APRIL STANDARDS.  THIS LOW WILL PULL
COOLER AIR INTO MICHIGAN STARTING MONDAY NIGHT...CYCLONIC FLOW
LINGERS INTO MIDWEEK.

PRIMARY FORECAST CONCERNS: VARYING PRECIPITATION CHANCES THROUGH
MIDWEEK...AS WELL AS PRECIPITATION TYPE.

MONDAY...12Z SOUNDINGS AND GOES SOUNDER IMAGERY SHOWS A NICE SURGE
OF MOISTURE COMING UP ACROSS THE SOUTHEASTERN STATES (1.00-1.50 INCH
PRECIPITABLE WATER) WHICH IS PUSHING A LARGE ARE OF RAIN NORTHWARD
ACROSS THE OHIO VALLEY...AND EVENTUALLY INTO MICHIGAN TONIGHT/MONDAY
MORNING.  THIS WILL PUSH THROUGH THE FORECAST AREA MONDAY MORNING
(PERHAPS FAIRLY QUICKLY) WITH MID LEVEL DRYING (POSSIBLY TAPERING
OFF TO A PERIOD OF DRIZZLE).  SURFACE LOW TRACKS ACROSS NORTHERN
LOWER MONDAY MORNING...BEHIND THAT A LINGERING BAND OF DEFORMATION/
FRONTOGENETIC PRECIPITATION WILL ROTATE IN FROM THE WEST DURING THE
AFTERNOON HOURS.  IN ADDITION...COULD SEE SOME CONVECTIVE PRECIP
CLOSE TO THE SOUTHEAST PORTION OF THE FORECAST AREA DURING THE LATE
MORNING/AFTERNOON WITH SOME ELEVATED INSTABILITY (TQ INDICES
POTENTIALLY IN THE 16-20C RANGE NEAR LOW LEVEL THETA-E RIDGE) AND
SECOND PIECE OF SOUTHERN BRANCH ENERGY SWINGING NORTHEAST ACROSS THE
LOWER PENINSULA.  MORE LIKELY THIS ACTIVITY WOULD OCCUR ACROSS THE
THUMB INTO LAKE HURON...BUT MAY BE CLOSE.  WILL NOT TRY AND VARY
PRECIP PROBABILITIES IN THE FORECAST GRIDS TO ACCOUNT FOR TIMING OF
VARIOUS WAVES OF PRECIPITATION (AS IT WILL BE WRONG ANYHOW)...WITH A
GENERIC HIGH LIKELY/CATEGORICAL POP THROUGH THE DAY SUFFICIENT FOR
NOW. AS LONG AS INITIAL AREA OF RAIN SCOOTS NORTH QUICKLY MONDAY
MORNING... NOT EXPECT A LOT OF RAINFALL IN THE 12Z-00Z TIME FRAME
(UNLESS CONVECTION CAN CLIP FAR EASTERN ZONES DURING THE AFTERNOON)
WITH FORECAST 12H QPF UNDER 0.25 INCH THOUGH COULD BE HIGHER ACROSS
EASTERN UPPER/FAR NORTHEAST LOWER GIVEN THE ABOVE CAVEATS.  TRACK OF
THE LOW RIGHT ACROSS LOWER MICHIGAN WILL LEAD TO SOME TRICKY
TEMPERATURE FORECASTS...IN GENERAL COOLER WEST AND WARMER EAST WITH
FALLING TEMPERATURES DURING THE MID/LATE AFTERNOON AS WINDS SWITCH
AROUND TO A MORE WESTERLY COMPONENT.

WHAT REMAINS OF DEFORMATION PRECIP BAND EXPECTED TO LIFT NORTHEAST
ACROSS NORTHERN MICHIGAN MONDAY EVENING...AFTER THAT MAY BE ON THE
QUIET SIDE OVERNIGHT AND WILL CONFINE POPS TO THE EVENING HOURS.
PRECIP TYPE MAY BE IN QUESTION ACROSS EASTERN UPPER AS DEPTH OF
SURFACE BASED WARM LAYER SHRINKS.  AS NORTHERN BRANCH SHORT WAVE
TROUGHS START GETTING INVOLVED IN THE FORECAST SCENARIO CAN`T RULE
OUT SOME ADDITIONAL SHOWERS DEVELOPING OVERNIGHT INTO TUESDAY
MORNING BUT NOT CONVINCED THE PROBABILITY RISES TO A SUFFICIENT
LEVEL TO INCLUDE IN THE FORECAST...WILL LEAVE IT OUT AND MAINTAIN
CONTINUITY.

TUESDAY...DEEP LAYER CYCLONIC FLOW ACROSS THE UPPER LAKES SPELLS
UNSETTLED AND NOT WARM WEATHER FOR TUESDAY.  DEEP MOISTURE WILL
ROTATE AROUND THE SOUTH SIDE OF THE UPPER LOW...AND COOL
TEMPERATURES ALOFT (AT OR BELOW -30C/500MB) WILL ADD A DIURNAL
COMPONENT TO SUPPORT SHOWERS...AND GIVEN COOL TEMPERATURES PRECIP
COULD FALL AS RAIN/SNOW/GRAUPEL.  GUSTY SOUTHWEST WINDS (20-30MPH
GUSTS PROBABLE NORTHERN LOWER) WON`T MAKE IT FEEL ANY WARMER...WITH
AFTERNOON HIGHS AROUND 40-MID 40S (10-15 DEGREES BELOW NORMAL).
SHOWERS WILL CONTINUE INTO TUESDAY NIGHT...COVERAGE MAY DECREASE
WITH ON DOWNWARD SIDE OF DIURNAL HEATING CYCLE BUT THEY WILL STILL
BE AROUND.  COOLING TEMPERATURES ALSO WILL TREND PRECIPITATION TO
ALL SNOW SHOWERS TUESDAY EVENING.

WEDNESDAY...MORE OF THE SAME FOR WEDNESDAY WITH CONTINUED COOL
CYCLONIC FLOW AND VARIOUS DISTURBANCES ROTATING AROUND THE PARENT
VORTEX.  HIGH TEMPERATURES PROBABLY A FEW DEGREES COOLER WEDNESDAY
AFTERNOON...WITH MORE TEMPERATURES STUCK BELOW 40 DEGREES LIKELY.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

THE PERIOD PICKS UP JUST AS THE PREVIOUS LEFT OFF WITH UPPER LEVEL
TROUGHING OVERHEAD AND MULTIPLE WEAK WAVES ROTATING THROUGH THE BASE
OF THE TROUGH...BRINGING RAIN/SNOW SHOWER CHANCES WEDNESDAY NIGHT
AND INTO THE DAY THURSDAY. AS MENTIONED BY PRIOR SHIFT...THE
MOVEMENT OF THE OVERALL PATTERN LOOKS MINIMAL THROUGH THE WEEKEND
WITH TROUGHING CLOSE ENOUGH WHERE ANY SUBTLE WAVE COULD KICK OFF
ADDITIONAL SHOWER ACTIVITY. HAVE GONE AHEAD AND ADDED LOW END CHANCE
POPS FOR THURSDAY NIGHT (MAINLY DIRECTLY DOWNWIND OF LAKE MICHIGAN
AND FOR THE EASTERN U.P.)...BUT WILL KEEP A MAINLY DRY FORECAST FROM
FRIDAY THROUGH SUNDAY AS THE MAJORITY OF THE TIME LOOKS TO REMAIN
PRECIPITATION FREE.

NO DOUBT THE OVERALL PATTERN WILL BE A RATHER CHILLY ONE...WITH H8
TEMPS APPROACHING -8C THROUGHOUT THE PERIOD. A BLENDED MODEL
GUIDANCE APPROACH WOULD SUGGEST HIGH TEMPERATURES STUCK IN THE UPPER
30S AND 40S (A SOLID 10-15 DEGREES BELOW NORMAL) AND LOWS MAINLY IN
THE 20S TO LOWER 30S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 100 AM EDT MON APR 20 2015

MAINLY MVFR CONDITIONS ARE EXPECTED AT ALL NRN LWR MICHIGAN TAF
SITES THRU 00Z TUESDAY AS WIDESPREAD RAIN SHOWERS CONTINUE TO
IMPACT THE REGION. CONDITIONS MAY BRIEFLY DROP TO IFR THRU EARLY
MORNING WITHIN HEAVIER RAIN SHOWERS. RAIN SHOWERS WILL BECOME
SCATTERED AFTER 00Z TUESDAY...WITH OVERALL CONDITIONS RETURNING TO
VFR...ALBEIT LOW VFR. EAST WINDS GUSTING TO 20 KTS THRU EARLY
MORNING WILL SHIFT TO THE W/SW BY AFTERNOON.

&&

.MARINE...
ISSUED AT 402 PM EDT SUN APR 19 2015

TONIGHT THROUGH TUESDAY...EAST WINDS AHEAD OF THE SFC LOW WILL
CONTINUE TO INCREASE ACROSS THE UPPER GREAT LAKES AS THE PRESSURE
GRADIENT TIGHTENS UP ESPECIALLY OVER LAKE HURON AND E UPPER. THE SFC
LOW MOVES OVER N LAKE MICHIGAN AND IT LOOKS LIKE THE GRADIENT SHOULD
JUST BE SLACK ENOUGH FOR THE WINDS TO REMAIN BELOW MOST OF THE SMALL
CRAFT CRITERIA IN THE NEARSHORE WATERS. ONCE THE SFC LOW MOVES NORTH
OF THE UPPER MICHIGAN, THE PRESSURE GRADIENT WILL TIGHTEN BRIEFLY
OVER THE UPPER GREAT LAKES BRINGING SMALL CRAFT CRITERIA TO MOST, IF
NOT ALL OF THE NEARSHORES MONDAY AFTERNOON AND MONDAY NIGHT.
TUESDAY, AS THE SFC LOW STALLS NORTH OF LAKE SUPERIOR, THE WINDS
WILL INCREASE AS THE GRADIENT AGAIN TIGHTENS, AND THEN RELAXES BY
THE AFTERNOON.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
     LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT THIS MORNING FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LSZ321-
     322.

&&

$$

UPDATE...JAZ
NEAR TERM...JSL
SHORT TERM...JPB
LONG TERM...GILLEN
AVIATION...MLR
MARINE...JSL



000
FXUS63 KAPX 200500
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
100 AM EDT MON APR 20 2015

.UPDATE...
ISSUED AT 935 PM EDT SUN APR 19 2015

IT HAS BEEN IN NO HURRY...BUT WIDESPREAD RAIN IS MAKING STEADY
INROADS NORTHWARD ACROSS CENTRAL LOWER MI. LEADING EDGE IS NOW A
BIT NORTH OF GLADWIN/STANDISH. AHEAD OF THIS...A BAND OF -SHRA
HAS ADVANCED TO A FRANKFORT-GLR-PRESQUE ISLE LT LINE. HAVE BEEN
ADJUSTING TIMING OF PRECIP ONSET...MAINLY TO SLOW THINGS DOWN A
BIT. BUT THE MAIN GIST OF THE FORECAST...I.E. EVERYONE EVENTUALLY
GETS WET TONIGHT...IS FINE.

&&

.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 402 PM EDT SUN APR 19 2015

HIGH IMPACT WEATHER: MINIMAL

FORECAST CHALLENGE: TIMING OF THE RAIN TONIGHT.

OVERVIEW...WHILE THE MOISTURE HAS BEEN INCREASING ALONG THE LAKE
HURON SHORE AND INLAND OF NE LOWER, NW LOWER HAS BEEN DRYING OUT
WITH A GOOD PORTION OF THE AREA WEST OF I-75 HAVING FALLEN BELOW
25%. IN E UPPER, THE RH HAS BEEN BETWEEN 40% AND 45%. WHAT THIS IS
DOING IS DELAYING THE RAIN SHIELD`S TRAVEL NORTH, WHICH HAD JUST
MADE IT TO THE MICHIGAN/INDIANA BORDER AROUND 19Z. USING THE TIMING
TOOL ON AWIPS, IT LOOKS LIKE THE RAIN SHOULD GET TO THE M-55
CORRIDOR AROUND 23Z, M-72 AROUND 00Z, M-32 AROUND 01Z, AND THE
STRAIT BETWEEN 02Z AND 03Z.

DETAILS FOR TONIGHT...AS WAS MENTIONED, TRYING TO TIME THIS SYSTEM
WITH THE DRY AIR IN THE LOWER LEVELS IS MADDENING. THE QUESTION
ISN`T IF THE AIR WILL LEAVE, BUT WHEN AS THE SFC LOW WILL, AS IT
MOVES UP FROM THE MID-MISSISSIPPI VALLEY, OVERWHELM WITH DRY AIR
WITH ITS MOISTURE, AND ALLOW THE RAIN TO FALL ALL THE WAY TO THE
SFC. HOWEVER, ONCE THE RAIN STARTS, IT WILL FALL THROUGH THE NIGHT
AS THE SFC NORTH OVER THE WESTERN PART OF THE STATE BETWEEN 06Z AND
12Z. THIS SFC LOW AND ASSOCIATED 500 MB SHORTWAVE TROUGH AND 50 KNOT
SPEED MAX THAT MOVES OVER THE STATE, OVER THE WARM FRONT. WITH THE
PWAT AROUND 1.0" OVERNIGHT OVER THE FORECAST AREA, WILL EXPECT
THAT A DECENT STEADY RAIN WILL RESULT.

&&

.SHORT TERM...(MONDAY THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

...SHOWERY/COOL/UNSETTLED THROUGH MIDWEEK...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: WELL-DEFINED SPLIT FLOW PATTERN FROM THE
END OF LAST WEEK NOW CONSOLIDATING AS NORTHERN BRANCH SHORT WAVE
TROUGH DIGS SOUTHEAST FROM WESTERN CANADA AND SCOOPS UP PESKY
SOUTHERN BRANCH VORTEX THAT HAS BEEN SPINNING ACROSS THE GREAT
BASIN/SOUTHERN ROCKIES SINCE THE MIDDLE OF LAST WEEK.  POSITIVE
PACIFIC TELECONNECTIONS LEADING TO A MORE AMPLIFIED PATTERN (BIG
TROUGH EAST OF THE DATELINE WITH +PNA RIDGING ALONG THE WEST COAST
OF NORTH AMERICA.  THIS CONSOLIDATING CENTRAL NORTH AMERICAN TROUGH
WILL BECOME THE PREDOMINANT WEATHER FEATURE THIS WEEK AS IT TAKES UP
RESIDENCE WITH REX BLOCKING ALONG THE WEST COAST...WITH AN UPPER LOW
EVENTUALLY PARKING ITSELF OVER THE GREAT LAKES BY MIDWEEK.

SOUTHERN BRANCH DISTURBANCE LOOKS TO COME OUT IN TWO PIECES
MONDAY...WHILE CLOSED CIRCULATION ALOFT DEVELOPS OVER NORTHWEST
ONTARIO/UPPER MIDWEST.  UPPER LOW THEN SETTLES OVER LAKE SUPERIOR
TUESDAY AND HANGS IN THROUGH MIDWEEK.  AT THE SURFACE...LEAD
SOUTHERN BRANCH SHORT WAVE TROUGH HAS AN ASSOCIATED SURFACE LOW OVER
THE MID MISSISSIPPI VALLEY THAT IS FORECAST TO DEEPEN AND LIFT NORTH
INTO LOWER MICHIGAN BY MONDAY MORNING...PROBABLY BELOW 990MB WHICH
IS PRETTY SIGNIFICANT BY MID-APRIL STANDARDS.  THIS LOW WILL PULL
COOLER AIR INTO MICHIGAN STARTING MONDAY NIGHT...CYCLONIC FLOW
LINGERS INTO MIDWEEK.

PRIMARY FORECAST CONCERNS: VARYING PRECIPITATION CHANCES THROUGH
MIDWEEK...AS WELL AS PRECIPITATION TYPE.

MONDAY...12Z SOUNDINGS AND GOES SOUNDER IMAGERY SHOWS A NICE SURGE
OF MOISTURE COMING UP ACROSS THE SOUTHEASTERN STATES (1.00-1.50 INCH
PRECIPITABLE WATER) WHICH IS PUSHING A LARGE ARE OF RAIN NORTHWARD
ACROSS THE OHIO VALLEY...AND EVENTUALLY INTO MICHIGAN TONIGHT/MONDAY
MORNING.  THIS WILL PUSH THROUGH THE FORECAST AREA MONDAY MORNING
(PERHAPS FAIRLY QUICKLY) WITH MID LEVEL DRYING (POSSIBLY TAPERING
OFF TO A PERIOD OF DRIZZLE).  SURFACE LOW TRACKS ACROSS NORTHERN
LOWER MONDAY MORNING...BEHIND THAT A LINGERING BAND OF DEFORMATION/
FRONTOGENETIC PRECIPITATION WILL ROTATE IN FROM THE WEST DURING THE
AFTERNOON HOURS.  IN ADDITION...COULD SEE SOME CONVECTIVE PRECIP
CLOSE TO THE SOUTHEAST PORTION OF THE FORECAST AREA DURING THE LATE
MORNING/AFTERNOON WITH SOME ELEVATED INSTABILITY (TQ INDICES
POTENTIALLY IN THE 16-20C RANGE NEAR LOW LEVEL THETA-E RIDGE) AND
SECOND PIECE OF SOUTHERN BRANCH ENERGY SWINGING NORTHEAST ACROSS THE
LOWER PENINSULA.  MORE LIKELY THIS ACTIVITY WOULD OCCUR ACROSS THE
THUMB INTO LAKE HURON...BUT MAY BE CLOSE.  WILL NOT TRY AND VARY
PRECIP PROBABILITIES IN THE FORECAST GRIDS TO ACCOUNT FOR TIMING OF
VARIOUS WAVES OF PRECIPITATION (AS IT WILL BE WRONG ANYHOW)...WITH A
GENERIC HIGH LIKELY/CATEGORICAL POP THROUGH THE DAY SUFFICIENT FOR
NOW. AS LONG AS INITIAL AREA OF RAIN SCOOTS NORTH QUICKLY MONDAY
MORNING... NOT EXPECT A LOT OF RAINFALL IN THE 12Z-00Z TIME FRAME
(UNLESS CONVECTION CAN CLIP FAR EASTERN ZONES DURING THE AFTERNOON)
WITH FORECAST 12H QPF UNDER 0.25 INCH THOUGH COULD BE HIGHER ACROSS
EASTERN UPPER/FAR NORTHEAST LOWER GIVEN THE ABOVE CAVEATS.  TRACK OF
THE LOW RIGHT ACROSS LOWER MICHIGAN WILL LEAD TO SOME TRICKY
TEMPERATURE FORECASTS...IN GENERAL COOLER WEST AND WARMER EAST WITH
FALLING TEMPERATURES DURING THE MID/LATE AFTERNOON AS WINDS SWITCH
AROUND TO A MORE WESTERLY COMPONENT.

WHAT REMAINS OF DEFORMATION PRECIP BAND EXPECTED TO LIFT NORTHEAST
ACROSS NORTHERN MICHIGAN MONDAY EVENING...AFTER THAT MAY BE ON THE
QUIET SIDE OVERNIGHT AND WILL CONFINE POPS TO THE EVENING HOURS.
PRECIP TYPE MAY BE IN QUESTION ACROSS EASTERN UPPER AS DEPTH OF
SURFACE BASED WARM LAYER SHRINKS.  AS NORTHERN BRANCH SHORT WAVE
TROUGHS START GETTING INVOLVED IN THE FORECAST SCENARIO CAN`T RULE
OUT SOME ADDITIONAL SHOWERS DEVELOPING OVERNIGHT INTO TUESDAY
MORNING BUT NOT CONVINCED THE PROBABILITY RISES TO A SUFFICIENT
LEVEL TO INCLUDE IN THE FORECAST...WILL LEAVE IT OUT AND MAINTAIN
CONTINUITY.

TUESDAY...DEEP LAYER CYCLONIC FLOW ACROSS THE UPPER LAKES SPELLS
UNSETTLED AND NOT WARM WEATHER FOR TUESDAY.  DEEP MOISTURE WILL
ROTATE AROUND THE SOUTH SIDE OF THE UPPER LOW...AND COOL
TEMPERATURES ALOFT (AT OR BELOW -30C/500MB) WILL ADD A DIURNAL
COMPONENT TO SUPPORT SHOWERS...AND GIVEN COOL TEMPERATURES PRECIP
COULD FALL AS RAIN/SNOW/GRAUPEL.  GUSTY SOUTHWEST WINDS (20-30MPH
GUSTS PROBABLE NORTHERN LOWER) WON`T MAKE IT FEEL ANY WARMER...WITH
AFTERNOON HIGHS AROUND 40-MID 40S (10-15 DEGREES BELOW NORMAL).
SHOWERS WILL CONTINUE INTO TUESDAY NIGHT...COVERAGE MAY DECREASE
WITH ON DOWNWARD SIDE OF DIURNAL HEATING CYCLE BUT THEY WILL STILL
BE AROUND.  COOLING TEMPERATURES ALSO WILL TREND PRECIPITATION TO
ALL SNOW SHOWERS TUESDAY EVENING.

WEDNESDAY...MORE OF THE SAME FOR WEDNESDAY WITH CONTINUED COOL
CYCLONIC FLOW AND VARIOUS DISTURBANCES ROTATING AROUND THE PARENT
VORTEX.  HIGH TEMPERATURES PROBABLY A FEW DEGREES COOLER WEDNESDAY
AFTERNOON...WITH MORE TEMPERATURES STUCK BELOW 40 DEGREES LIKELY.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

THE PERIOD PICKS UP JUST AS THE PREVIOUS LEFT OFF WITH UPPER LEVEL
TROUGHING OVERHEAD AND MULTIPLE WEAK WAVES ROTATING THROUGH THE BASE
OF THE TROUGH...BRINGING RAIN/SNOW SHOWER CHANCES WEDNESDAY NIGHT
AND INTO THE DAY THURSDAY. AS MENTIONED BY PRIOR SHIFT...THE
MOVEMENT OF THE OVERALL PATTERN LOOKS MINIMAL THROUGH THE WEEKEND
WITH TROUGHING CLOSE ENOUGH WHERE ANY SUBTLE WAVE COULD KICK OFF
ADDITIONAL SHOWER ACTIVITY. HAVE GONE AHEAD AND ADDED LOW END CHANCE
POPS FOR THURSDAY NIGHT (MAINLY DIRECTLY DOWNWIND OF LAKE MICHIGAN
AND FOR THE EASTERN U.P.)...BUT WILL KEEP A MAINLY DRY FORECAST FROM
FRIDAY THROUGH SUNDAY AS THE MAJORITY OF THE TIME LOOKS TO REMAIN
PRECIPITATION FREE.

NO DOUBT THE OVERALL PATTERN WILL BE A RATHER CHILLY ONE...WITH H8
TEMPS APPROACHING -8C THROUGHOUT THE PERIOD. A BLENDED MODEL
GUIDANCE APPROACH WOULD SUGGEST HIGH TEMPERATURES STUCK IN THE UPPER
30S AND 40S (A SOLID 10-15 DEGREES BELOW NORMAL) AND LOWS MAINLY IN
THE 20S TO LOWER 30S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 100 AM EDT MON APR 20 2015

MAINLY MVFR CONDITIONS ARE EXPECTED AT ALL NRN LWR MICHIGAN TAF
SITES THRU 00Z TUESDAY AS WIDESPREAD RAIN SHOWERS CONTINUE TO
IMPACT THE REGION. CONDITIONS MAY BRIEFLY DROP TO IFR THRU EARLY
MORNING WITHIN HEAVIER RAIN SHOWERS. RAIN SHOWERS WILL BECOME
SCATTERED AFTER 00Z TUESDAY...WITH OVERALL CONDITIONS RETURNING TO
VFR...ALBEIT LOW VFR. EAST WINDS GUSTING TO 20 KTS THRU EARLY
MORNING WILL SHIFT TO THE W/SW BY AFTERNOON.

&&

.MARINE...
ISSUED AT 402 PM EDT SUN APR 19 2015

TONIGHT THROUGH TUESDAY...EAST WINDS AHEAD OF THE SFC LOW WILL
CONTINUE TO INCREASE ACROSS THE UPPER GREAT LAKES AS THE PRESSURE
GRADIENT TIGHTENS UP ESPECIALLY OVER LAKE HURON AND E UPPER. THE SFC
LOW MOVES OVER N LAKE MICHIGAN AND IT LOOKS LIKE THE GRADIENT SHOULD
JUST BE SLACK ENOUGH FOR THE WINDS TO REMAIN BELOW MOST OF THE SMALL
CRAFT CRITERIA IN THE NEARSHORE WATERS. ONCE THE SFC LOW MOVES NORTH
OF THE UPPER MICHIGAN, THE PRESSURE GRADIENT WILL TIGHTEN BRIEFLY
OVER THE UPPER GREAT LAKES BRINGING SMALL CRAFT CRITERIA TO MOST, IF
NOT ALL OF THE NEARSHORES MONDAY AFTERNOON AND MONDAY NIGHT.
TUESDAY, AS THE SFC LOW STALLS NORTH OF LAKE SUPERIOR, THE WINDS
WILL INCREASE AS THE GRADIENT AGAIN TIGHTENS, AND THEN RELAXES BY
THE AFTERNOON.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
     LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT THIS MORNING FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LSZ321-
     322.

&&

$$

UPDATE...JAZ
NEAR TERM...JSL
SHORT TERM...JPB
LONG TERM...GILLEN
AVIATION...MLR
MARINE...JSL



000
FXUS63 KAPX 200500
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
100 AM EDT MON APR 20 2015

.UPDATE...
ISSUED AT 935 PM EDT SUN APR 19 2015

IT HAS BEEN IN NO HURRY...BUT WIDESPREAD RAIN IS MAKING STEADY
INROADS NORTHWARD ACROSS CENTRAL LOWER MI. LEADING EDGE IS NOW A
BIT NORTH OF GLADWIN/STANDISH. AHEAD OF THIS...A BAND OF -SHRA
HAS ADVANCED TO A FRANKFORT-GLR-PRESQUE ISLE LT LINE. HAVE BEEN
ADJUSTING TIMING OF PRECIP ONSET...MAINLY TO SLOW THINGS DOWN A
BIT. BUT THE MAIN GIST OF THE FORECAST...I.E. EVERYONE EVENTUALLY
GETS WET TONIGHT...IS FINE.

&&

.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 402 PM EDT SUN APR 19 2015

HIGH IMPACT WEATHER: MINIMAL

FORECAST CHALLENGE: TIMING OF THE RAIN TONIGHT.

OVERVIEW...WHILE THE MOISTURE HAS BEEN INCREASING ALONG THE LAKE
HURON SHORE AND INLAND OF NE LOWER, NW LOWER HAS BEEN DRYING OUT
WITH A GOOD PORTION OF THE AREA WEST OF I-75 HAVING FALLEN BELOW
25%. IN E UPPER, THE RH HAS BEEN BETWEEN 40% AND 45%. WHAT THIS IS
DOING IS DELAYING THE RAIN SHIELD`S TRAVEL NORTH, WHICH HAD JUST
MADE IT TO THE MICHIGAN/INDIANA BORDER AROUND 19Z. USING THE TIMING
TOOL ON AWIPS, IT LOOKS LIKE THE RAIN SHOULD GET TO THE M-55
CORRIDOR AROUND 23Z, M-72 AROUND 00Z, M-32 AROUND 01Z, AND THE
STRAIT BETWEEN 02Z AND 03Z.

DETAILS FOR TONIGHT...AS WAS MENTIONED, TRYING TO TIME THIS SYSTEM
WITH THE DRY AIR IN THE LOWER LEVELS IS MADDENING. THE QUESTION
ISN`T IF THE AIR WILL LEAVE, BUT WHEN AS THE SFC LOW WILL, AS IT
MOVES UP FROM THE MID-MISSISSIPPI VALLEY, OVERWHELM WITH DRY AIR
WITH ITS MOISTURE, AND ALLOW THE RAIN TO FALL ALL THE WAY TO THE
SFC. HOWEVER, ONCE THE RAIN STARTS, IT WILL FALL THROUGH THE NIGHT
AS THE SFC NORTH OVER THE WESTERN PART OF THE STATE BETWEEN 06Z AND
12Z. THIS SFC LOW AND ASSOCIATED 500 MB SHORTWAVE TROUGH AND 50 KNOT
SPEED MAX THAT MOVES OVER THE STATE, OVER THE WARM FRONT. WITH THE
PWAT AROUND 1.0" OVERNIGHT OVER THE FORECAST AREA, WILL EXPECT
THAT A DECENT STEADY RAIN WILL RESULT.

&&

.SHORT TERM...(MONDAY THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

...SHOWERY/COOL/UNSETTLED THROUGH MIDWEEK...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: WELL-DEFINED SPLIT FLOW PATTERN FROM THE
END OF LAST WEEK NOW CONSOLIDATING AS NORTHERN BRANCH SHORT WAVE
TROUGH DIGS SOUTHEAST FROM WESTERN CANADA AND SCOOPS UP PESKY
SOUTHERN BRANCH VORTEX THAT HAS BEEN SPINNING ACROSS THE GREAT
BASIN/SOUTHERN ROCKIES SINCE THE MIDDLE OF LAST WEEK.  POSITIVE
PACIFIC TELECONNECTIONS LEADING TO A MORE AMPLIFIED PATTERN (BIG
TROUGH EAST OF THE DATELINE WITH +PNA RIDGING ALONG THE WEST COAST
OF NORTH AMERICA.  THIS CONSOLIDATING CENTRAL NORTH AMERICAN TROUGH
WILL BECOME THE PREDOMINANT WEATHER FEATURE THIS WEEK AS IT TAKES UP
RESIDENCE WITH REX BLOCKING ALONG THE WEST COAST...WITH AN UPPER LOW
EVENTUALLY PARKING ITSELF OVER THE GREAT LAKES BY MIDWEEK.

SOUTHERN BRANCH DISTURBANCE LOOKS TO COME OUT IN TWO PIECES
MONDAY...WHILE CLOSED CIRCULATION ALOFT DEVELOPS OVER NORTHWEST
ONTARIO/UPPER MIDWEST.  UPPER LOW THEN SETTLES OVER LAKE SUPERIOR
TUESDAY AND HANGS IN THROUGH MIDWEEK.  AT THE SURFACE...LEAD
SOUTHERN BRANCH SHORT WAVE TROUGH HAS AN ASSOCIATED SURFACE LOW OVER
THE MID MISSISSIPPI VALLEY THAT IS FORECAST TO DEEPEN AND LIFT NORTH
INTO LOWER MICHIGAN BY MONDAY MORNING...PROBABLY BELOW 990MB WHICH
IS PRETTY SIGNIFICANT BY MID-APRIL STANDARDS.  THIS LOW WILL PULL
COOLER AIR INTO MICHIGAN STARTING MONDAY NIGHT...CYCLONIC FLOW
LINGERS INTO MIDWEEK.

PRIMARY FORECAST CONCERNS: VARYING PRECIPITATION CHANCES THROUGH
MIDWEEK...AS WELL AS PRECIPITATION TYPE.

MONDAY...12Z SOUNDINGS AND GOES SOUNDER IMAGERY SHOWS A NICE SURGE
OF MOISTURE COMING UP ACROSS THE SOUTHEASTERN STATES (1.00-1.50 INCH
PRECIPITABLE WATER) WHICH IS PUSHING A LARGE ARE OF RAIN NORTHWARD
ACROSS THE OHIO VALLEY...AND EVENTUALLY INTO MICHIGAN TONIGHT/MONDAY
MORNING.  THIS WILL PUSH THROUGH THE FORECAST AREA MONDAY MORNING
(PERHAPS FAIRLY QUICKLY) WITH MID LEVEL DRYING (POSSIBLY TAPERING
OFF TO A PERIOD OF DRIZZLE).  SURFACE LOW TRACKS ACROSS NORTHERN
LOWER MONDAY MORNING...BEHIND THAT A LINGERING BAND OF DEFORMATION/
FRONTOGENETIC PRECIPITATION WILL ROTATE IN FROM THE WEST DURING THE
AFTERNOON HOURS.  IN ADDITION...COULD SEE SOME CONVECTIVE PRECIP
CLOSE TO THE SOUTHEAST PORTION OF THE FORECAST AREA DURING THE LATE
MORNING/AFTERNOON WITH SOME ELEVATED INSTABILITY (TQ INDICES
POTENTIALLY IN THE 16-20C RANGE NEAR LOW LEVEL THETA-E RIDGE) AND
SECOND PIECE OF SOUTHERN BRANCH ENERGY SWINGING NORTHEAST ACROSS THE
LOWER PENINSULA.  MORE LIKELY THIS ACTIVITY WOULD OCCUR ACROSS THE
THUMB INTO LAKE HURON...BUT MAY BE CLOSE.  WILL NOT TRY AND VARY
PRECIP PROBABILITIES IN THE FORECAST GRIDS TO ACCOUNT FOR TIMING OF
VARIOUS WAVES OF PRECIPITATION (AS IT WILL BE WRONG ANYHOW)...WITH A
GENERIC HIGH LIKELY/CATEGORICAL POP THROUGH THE DAY SUFFICIENT FOR
NOW. AS LONG AS INITIAL AREA OF RAIN SCOOTS NORTH QUICKLY MONDAY
MORNING... NOT EXPECT A LOT OF RAINFALL IN THE 12Z-00Z TIME FRAME
(UNLESS CONVECTION CAN CLIP FAR EASTERN ZONES DURING THE AFTERNOON)
WITH FORECAST 12H QPF UNDER 0.25 INCH THOUGH COULD BE HIGHER ACROSS
EASTERN UPPER/FAR NORTHEAST LOWER GIVEN THE ABOVE CAVEATS.  TRACK OF
THE LOW RIGHT ACROSS LOWER MICHIGAN WILL LEAD TO SOME TRICKY
TEMPERATURE FORECASTS...IN GENERAL COOLER WEST AND WARMER EAST WITH
FALLING TEMPERATURES DURING THE MID/LATE AFTERNOON AS WINDS SWITCH
AROUND TO A MORE WESTERLY COMPONENT.

WHAT REMAINS OF DEFORMATION PRECIP BAND EXPECTED TO LIFT NORTHEAST
ACROSS NORTHERN MICHIGAN MONDAY EVENING...AFTER THAT MAY BE ON THE
QUIET SIDE OVERNIGHT AND WILL CONFINE POPS TO THE EVENING HOURS.
PRECIP TYPE MAY BE IN QUESTION ACROSS EASTERN UPPER AS DEPTH OF
SURFACE BASED WARM LAYER SHRINKS.  AS NORTHERN BRANCH SHORT WAVE
TROUGHS START GETTING INVOLVED IN THE FORECAST SCENARIO CAN`T RULE
OUT SOME ADDITIONAL SHOWERS DEVELOPING OVERNIGHT INTO TUESDAY
MORNING BUT NOT CONVINCED THE PROBABILITY RISES TO A SUFFICIENT
LEVEL TO INCLUDE IN THE FORECAST...WILL LEAVE IT OUT AND MAINTAIN
CONTINUITY.

TUESDAY...DEEP LAYER CYCLONIC FLOW ACROSS THE UPPER LAKES SPELLS
UNSETTLED AND NOT WARM WEATHER FOR TUESDAY.  DEEP MOISTURE WILL
ROTATE AROUND THE SOUTH SIDE OF THE UPPER LOW...AND COOL
TEMPERATURES ALOFT (AT OR BELOW -30C/500MB) WILL ADD A DIURNAL
COMPONENT TO SUPPORT SHOWERS...AND GIVEN COOL TEMPERATURES PRECIP
COULD FALL AS RAIN/SNOW/GRAUPEL.  GUSTY SOUTHWEST WINDS (20-30MPH
GUSTS PROBABLE NORTHERN LOWER) WON`T MAKE IT FEEL ANY WARMER...WITH
AFTERNOON HIGHS AROUND 40-MID 40S (10-15 DEGREES BELOW NORMAL).
SHOWERS WILL CONTINUE INTO TUESDAY NIGHT...COVERAGE MAY DECREASE
WITH ON DOWNWARD SIDE OF DIURNAL HEATING CYCLE BUT THEY WILL STILL
BE AROUND.  COOLING TEMPERATURES ALSO WILL TREND PRECIPITATION TO
ALL SNOW SHOWERS TUESDAY EVENING.

WEDNESDAY...MORE OF THE SAME FOR WEDNESDAY WITH CONTINUED COOL
CYCLONIC FLOW AND VARIOUS DISTURBANCES ROTATING AROUND THE PARENT
VORTEX.  HIGH TEMPERATURES PROBABLY A FEW DEGREES COOLER WEDNESDAY
AFTERNOON...WITH MORE TEMPERATURES STUCK BELOW 40 DEGREES LIKELY.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

THE PERIOD PICKS UP JUST AS THE PREVIOUS LEFT OFF WITH UPPER LEVEL
TROUGHING OVERHEAD AND MULTIPLE WEAK WAVES ROTATING THROUGH THE BASE
OF THE TROUGH...BRINGING RAIN/SNOW SHOWER CHANCES WEDNESDAY NIGHT
AND INTO THE DAY THURSDAY. AS MENTIONED BY PRIOR SHIFT...THE
MOVEMENT OF THE OVERALL PATTERN LOOKS MINIMAL THROUGH THE WEEKEND
WITH TROUGHING CLOSE ENOUGH WHERE ANY SUBTLE WAVE COULD KICK OFF
ADDITIONAL SHOWER ACTIVITY. HAVE GONE AHEAD AND ADDED LOW END CHANCE
POPS FOR THURSDAY NIGHT (MAINLY DIRECTLY DOWNWIND OF LAKE MICHIGAN
AND FOR THE EASTERN U.P.)...BUT WILL KEEP A MAINLY DRY FORECAST FROM
FRIDAY THROUGH SUNDAY AS THE MAJORITY OF THE TIME LOOKS TO REMAIN
PRECIPITATION FREE.

NO DOUBT THE OVERALL PATTERN WILL BE A RATHER CHILLY ONE...WITH H8
TEMPS APPROACHING -8C THROUGHOUT THE PERIOD. A BLENDED MODEL
GUIDANCE APPROACH WOULD SUGGEST HIGH TEMPERATURES STUCK IN THE UPPER
30S AND 40S (A SOLID 10-15 DEGREES BELOW NORMAL) AND LOWS MAINLY IN
THE 20S TO LOWER 30S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 100 AM EDT MON APR 20 2015

MAINLY MVFR CONDITIONS ARE EXPECTED AT ALL NRN LWR MICHIGAN TAF
SITES THRU 00Z TUESDAY AS WIDESPREAD RAIN SHOWERS CONTINUE TO
IMPACT THE REGION. CONDITIONS MAY BRIEFLY DROP TO IFR THRU EARLY
MORNING WITHIN HEAVIER RAIN SHOWERS. RAIN SHOWERS WILL BECOME
SCATTERED AFTER 00Z TUESDAY...WITH OVERALL CONDITIONS RETURNING TO
VFR...ALBEIT LOW VFR. EAST WINDS GUSTING TO 20 KTS THRU EARLY
MORNING WILL SHIFT TO THE W/SW BY AFTERNOON.

&&

.MARINE...
ISSUED AT 402 PM EDT SUN APR 19 2015

TONIGHT THROUGH TUESDAY...EAST WINDS AHEAD OF THE SFC LOW WILL
CONTINUE TO INCREASE ACROSS THE UPPER GREAT LAKES AS THE PRESSURE
GRADIENT TIGHTENS UP ESPECIALLY OVER LAKE HURON AND E UPPER. THE SFC
LOW MOVES OVER N LAKE MICHIGAN AND IT LOOKS LIKE THE GRADIENT SHOULD
JUST BE SLACK ENOUGH FOR THE WINDS TO REMAIN BELOW MOST OF THE SMALL
CRAFT CRITERIA IN THE NEARSHORE WATERS. ONCE THE SFC LOW MOVES NORTH
OF THE UPPER MICHIGAN, THE PRESSURE GRADIENT WILL TIGHTEN BRIEFLY
OVER THE UPPER GREAT LAKES BRINGING SMALL CRAFT CRITERIA TO MOST, IF
NOT ALL OF THE NEARSHORES MONDAY AFTERNOON AND MONDAY NIGHT.
TUESDAY, AS THE SFC LOW STALLS NORTH OF LAKE SUPERIOR, THE WINDS
WILL INCREASE AS THE GRADIENT AGAIN TIGHTENS, AND THEN RELAXES BY
THE AFTERNOON.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
     LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT THIS MORNING FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LSZ321-
     322.

&&

$$

UPDATE...JAZ
NEAR TERM...JSL
SHORT TERM...JPB
LONG TERM...GILLEN
AVIATION...MLR
MARINE...JSL



000
FXUS63 KAPX 200500
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
100 AM EDT MON APR 20 2015

.UPDATE...
ISSUED AT 935 PM EDT SUN APR 19 2015

IT HAS BEEN IN NO HURRY...BUT WIDESPREAD RAIN IS MAKING STEADY
INROADS NORTHWARD ACROSS CENTRAL LOWER MI. LEADING EDGE IS NOW A
BIT NORTH OF GLADWIN/STANDISH. AHEAD OF THIS...A BAND OF -SHRA
HAS ADVANCED TO A FRANKFORT-GLR-PRESQUE ISLE LT LINE. HAVE BEEN
ADJUSTING TIMING OF PRECIP ONSET...MAINLY TO SLOW THINGS DOWN A
BIT. BUT THE MAIN GIST OF THE FORECAST...I.E. EVERYONE EVENTUALLY
GETS WET TONIGHT...IS FINE.

&&

.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 402 PM EDT SUN APR 19 2015

HIGH IMPACT WEATHER: MINIMAL

FORECAST CHALLENGE: TIMING OF THE RAIN TONIGHT.

OVERVIEW...WHILE THE MOISTURE HAS BEEN INCREASING ALONG THE LAKE
HURON SHORE AND INLAND OF NE LOWER, NW LOWER HAS BEEN DRYING OUT
WITH A GOOD PORTION OF THE AREA WEST OF I-75 HAVING FALLEN BELOW
25%. IN E UPPER, THE RH HAS BEEN BETWEEN 40% AND 45%. WHAT THIS IS
DOING IS DELAYING THE RAIN SHIELD`S TRAVEL NORTH, WHICH HAD JUST
MADE IT TO THE MICHIGAN/INDIANA BORDER AROUND 19Z. USING THE TIMING
TOOL ON AWIPS, IT LOOKS LIKE THE RAIN SHOULD GET TO THE M-55
CORRIDOR AROUND 23Z, M-72 AROUND 00Z, M-32 AROUND 01Z, AND THE
STRAIT BETWEEN 02Z AND 03Z.

DETAILS FOR TONIGHT...AS WAS MENTIONED, TRYING TO TIME THIS SYSTEM
WITH THE DRY AIR IN THE LOWER LEVELS IS MADDENING. THE QUESTION
ISN`T IF THE AIR WILL LEAVE, BUT WHEN AS THE SFC LOW WILL, AS IT
MOVES UP FROM THE MID-MISSISSIPPI VALLEY, OVERWHELM WITH DRY AIR
WITH ITS MOISTURE, AND ALLOW THE RAIN TO FALL ALL THE WAY TO THE
SFC. HOWEVER, ONCE THE RAIN STARTS, IT WILL FALL THROUGH THE NIGHT
AS THE SFC NORTH OVER THE WESTERN PART OF THE STATE BETWEEN 06Z AND
12Z. THIS SFC LOW AND ASSOCIATED 500 MB SHORTWAVE TROUGH AND 50 KNOT
SPEED MAX THAT MOVES OVER THE STATE, OVER THE WARM FRONT. WITH THE
PWAT AROUND 1.0" OVERNIGHT OVER THE FORECAST AREA, WILL EXPECT
THAT A DECENT STEADY RAIN WILL RESULT.

&&

.SHORT TERM...(MONDAY THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

...SHOWERY/COOL/UNSETTLED THROUGH MIDWEEK...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: WELL-DEFINED SPLIT FLOW PATTERN FROM THE
END OF LAST WEEK NOW CONSOLIDATING AS NORTHERN BRANCH SHORT WAVE
TROUGH DIGS SOUTHEAST FROM WESTERN CANADA AND SCOOPS UP PESKY
SOUTHERN BRANCH VORTEX THAT HAS BEEN SPINNING ACROSS THE GREAT
BASIN/SOUTHERN ROCKIES SINCE THE MIDDLE OF LAST WEEK.  POSITIVE
PACIFIC TELECONNECTIONS LEADING TO A MORE AMPLIFIED PATTERN (BIG
TROUGH EAST OF THE DATELINE WITH +PNA RIDGING ALONG THE WEST COAST
OF NORTH AMERICA.  THIS CONSOLIDATING CENTRAL NORTH AMERICAN TROUGH
WILL BECOME THE PREDOMINANT WEATHER FEATURE THIS WEEK AS IT TAKES UP
RESIDENCE WITH REX BLOCKING ALONG THE WEST COAST...WITH AN UPPER LOW
EVENTUALLY PARKING ITSELF OVER THE GREAT LAKES BY MIDWEEK.

SOUTHERN BRANCH DISTURBANCE LOOKS TO COME OUT IN TWO PIECES
MONDAY...WHILE CLOSED CIRCULATION ALOFT DEVELOPS OVER NORTHWEST
ONTARIO/UPPER MIDWEST.  UPPER LOW THEN SETTLES OVER LAKE SUPERIOR
TUESDAY AND HANGS IN THROUGH MIDWEEK.  AT THE SURFACE...LEAD
SOUTHERN BRANCH SHORT WAVE TROUGH HAS AN ASSOCIATED SURFACE LOW OVER
THE MID MISSISSIPPI VALLEY THAT IS FORECAST TO DEEPEN AND LIFT NORTH
INTO LOWER MICHIGAN BY MONDAY MORNING...PROBABLY BELOW 990MB WHICH
IS PRETTY SIGNIFICANT BY MID-APRIL STANDARDS.  THIS LOW WILL PULL
COOLER AIR INTO MICHIGAN STARTING MONDAY NIGHT...CYCLONIC FLOW
LINGERS INTO MIDWEEK.

PRIMARY FORECAST CONCERNS: VARYING PRECIPITATION CHANCES THROUGH
MIDWEEK...AS WELL AS PRECIPITATION TYPE.

MONDAY...12Z SOUNDINGS AND GOES SOUNDER IMAGERY SHOWS A NICE SURGE
OF MOISTURE COMING UP ACROSS THE SOUTHEASTERN STATES (1.00-1.50 INCH
PRECIPITABLE WATER) WHICH IS PUSHING A LARGE ARE OF RAIN NORTHWARD
ACROSS THE OHIO VALLEY...AND EVENTUALLY INTO MICHIGAN TONIGHT/MONDAY
MORNING.  THIS WILL PUSH THROUGH THE FORECAST AREA MONDAY MORNING
(PERHAPS FAIRLY QUICKLY) WITH MID LEVEL DRYING (POSSIBLY TAPERING
OFF TO A PERIOD OF DRIZZLE).  SURFACE LOW TRACKS ACROSS NORTHERN
LOWER MONDAY MORNING...BEHIND THAT A LINGERING BAND OF DEFORMATION/
FRONTOGENETIC PRECIPITATION WILL ROTATE IN FROM THE WEST DURING THE
AFTERNOON HOURS.  IN ADDITION...COULD SEE SOME CONVECTIVE PRECIP
CLOSE TO THE SOUTHEAST PORTION OF THE FORECAST AREA DURING THE LATE
MORNING/AFTERNOON WITH SOME ELEVATED INSTABILITY (TQ INDICES
POTENTIALLY IN THE 16-20C RANGE NEAR LOW LEVEL THETA-E RIDGE) AND
SECOND PIECE OF SOUTHERN BRANCH ENERGY SWINGING NORTHEAST ACROSS THE
LOWER PENINSULA.  MORE LIKELY THIS ACTIVITY WOULD OCCUR ACROSS THE
THUMB INTO LAKE HURON...BUT MAY BE CLOSE.  WILL NOT TRY AND VARY
PRECIP PROBABILITIES IN THE FORECAST GRIDS TO ACCOUNT FOR TIMING OF
VARIOUS WAVES OF PRECIPITATION (AS IT WILL BE WRONG ANYHOW)...WITH A
GENERIC HIGH LIKELY/CATEGORICAL POP THROUGH THE DAY SUFFICIENT FOR
NOW. AS LONG AS INITIAL AREA OF RAIN SCOOTS NORTH QUICKLY MONDAY
MORNING... NOT EXPECT A LOT OF RAINFALL IN THE 12Z-00Z TIME FRAME
(UNLESS CONVECTION CAN CLIP FAR EASTERN ZONES DURING THE AFTERNOON)
WITH FORECAST 12H QPF UNDER 0.25 INCH THOUGH COULD BE HIGHER ACROSS
EASTERN UPPER/FAR NORTHEAST LOWER GIVEN THE ABOVE CAVEATS.  TRACK OF
THE LOW RIGHT ACROSS LOWER MICHIGAN WILL LEAD TO SOME TRICKY
TEMPERATURE FORECASTS...IN GENERAL COOLER WEST AND WARMER EAST WITH
FALLING TEMPERATURES DURING THE MID/LATE AFTERNOON AS WINDS SWITCH
AROUND TO A MORE WESTERLY COMPONENT.

WHAT REMAINS OF DEFORMATION PRECIP BAND EXPECTED TO LIFT NORTHEAST
ACROSS NORTHERN MICHIGAN MONDAY EVENING...AFTER THAT MAY BE ON THE
QUIET SIDE OVERNIGHT AND WILL CONFINE POPS TO THE EVENING HOURS.
PRECIP TYPE MAY BE IN QUESTION ACROSS EASTERN UPPER AS DEPTH OF
SURFACE BASED WARM LAYER SHRINKS.  AS NORTHERN BRANCH SHORT WAVE
TROUGHS START GETTING INVOLVED IN THE FORECAST SCENARIO CAN`T RULE
OUT SOME ADDITIONAL SHOWERS DEVELOPING OVERNIGHT INTO TUESDAY
MORNING BUT NOT CONVINCED THE PROBABILITY RISES TO A SUFFICIENT
LEVEL TO INCLUDE IN THE FORECAST...WILL LEAVE IT OUT AND MAINTAIN
CONTINUITY.

TUESDAY...DEEP LAYER CYCLONIC FLOW ACROSS THE UPPER LAKES SPELLS
UNSETTLED AND NOT WARM WEATHER FOR TUESDAY.  DEEP MOISTURE WILL
ROTATE AROUND THE SOUTH SIDE OF THE UPPER LOW...AND COOL
TEMPERATURES ALOFT (AT OR BELOW -30C/500MB) WILL ADD A DIURNAL
COMPONENT TO SUPPORT SHOWERS...AND GIVEN COOL TEMPERATURES PRECIP
COULD FALL AS RAIN/SNOW/GRAUPEL.  GUSTY SOUTHWEST WINDS (20-30MPH
GUSTS PROBABLE NORTHERN LOWER) WON`T MAKE IT FEEL ANY WARMER...WITH
AFTERNOON HIGHS AROUND 40-MID 40S (10-15 DEGREES BELOW NORMAL).
SHOWERS WILL CONTINUE INTO TUESDAY NIGHT...COVERAGE MAY DECREASE
WITH ON DOWNWARD SIDE OF DIURNAL HEATING CYCLE BUT THEY WILL STILL
BE AROUND.  COOLING TEMPERATURES ALSO WILL TREND PRECIPITATION TO
ALL SNOW SHOWERS TUESDAY EVENING.

WEDNESDAY...MORE OF THE SAME FOR WEDNESDAY WITH CONTINUED COOL
CYCLONIC FLOW AND VARIOUS DISTURBANCES ROTATING AROUND THE PARENT
VORTEX.  HIGH TEMPERATURES PROBABLY A FEW DEGREES COOLER WEDNESDAY
AFTERNOON...WITH MORE TEMPERATURES STUCK BELOW 40 DEGREES LIKELY.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

THE PERIOD PICKS UP JUST AS THE PREVIOUS LEFT OFF WITH UPPER LEVEL
TROUGHING OVERHEAD AND MULTIPLE WEAK WAVES ROTATING THROUGH THE BASE
OF THE TROUGH...BRINGING RAIN/SNOW SHOWER CHANCES WEDNESDAY NIGHT
AND INTO THE DAY THURSDAY. AS MENTIONED BY PRIOR SHIFT...THE
MOVEMENT OF THE OVERALL PATTERN LOOKS MINIMAL THROUGH THE WEEKEND
WITH TROUGHING CLOSE ENOUGH WHERE ANY SUBTLE WAVE COULD KICK OFF
ADDITIONAL SHOWER ACTIVITY. HAVE GONE AHEAD AND ADDED LOW END CHANCE
POPS FOR THURSDAY NIGHT (MAINLY DIRECTLY DOWNWIND OF LAKE MICHIGAN
AND FOR THE EASTERN U.P.)...BUT WILL KEEP A MAINLY DRY FORECAST FROM
FRIDAY THROUGH SUNDAY AS THE MAJORITY OF THE TIME LOOKS TO REMAIN
PRECIPITATION FREE.

NO DOUBT THE OVERALL PATTERN WILL BE A RATHER CHILLY ONE...WITH H8
TEMPS APPROACHING -8C THROUGHOUT THE PERIOD. A BLENDED MODEL
GUIDANCE APPROACH WOULD SUGGEST HIGH TEMPERATURES STUCK IN THE UPPER
30S AND 40S (A SOLID 10-15 DEGREES BELOW NORMAL) AND LOWS MAINLY IN
THE 20S TO LOWER 30S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 100 AM EDT MON APR 20 2015

MAINLY MVFR CONDITIONS ARE EXPECTED AT ALL NRN LWR MICHIGAN TAF
SITES THRU 00Z TUESDAY AS WIDESPREAD RAIN SHOWERS CONTINUE TO
IMPACT THE REGION. CONDITIONS MAY BRIEFLY DROP TO IFR THRU EARLY
MORNING WITHIN HEAVIER RAIN SHOWERS. RAIN SHOWERS WILL BECOME
SCATTERED AFTER 00Z TUESDAY...WITH OVERALL CONDITIONS RETURNING TO
VFR...ALBEIT LOW VFR. EAST WINDS GUSTING TO 20 KTS THRU EARLY
MORNING WILL SHIFT TO THE W/SW BY AFTERNOON.

&&

.MARINE...
ISSUED AT 402 PM EDT SUN APR 19 2015

TONIGHT THROUGH TUESDAY...EAST WINDS AHEAD OF THE SFC LOW WILL
CONTINUE TO INCREASE ACROSS THE UPPER GREAT LAKES AS THE PRESSURE
GRADIENT TIGHTENS UP ESPECIALLY OVER LAKE HURON AND E UPPER. THE SFC
LOW MOVES OVER N LAKE MICHIGAN AND IT LOOKS LIKE THE GRADIENT SHOULD
JUST BE SLACK ENOUGH FOR THE WINDS TO REMAIN BELOW MOST OF THE SMALL
CRAFT CRITERIA IN THE NEARSHORE WATERS. ONCE THE SFC LOW MOVES NORTH
OF THE UPPER MICHIGAN, THE PRESSURE GRADIENT WILL TIGHTEN BRIEFLY
OVER THE UPPER GREAT LAKES BRINGING SMALL CRAFT CRITERIA TO MOST, IF
NOT ALL OF THE NEARSHORES MONDAY AFTERNOON AND MONDAY NIGHT.
TUESDAY, AS THE SFC LOW STALLS NORTH OF LAKE SUPERIOR, THE WINDS
WILL INCREASE AS THE GRADIENT AGAIN TIGHTENS, AND THEN RELAXES BY
THE AFTERNOON.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
     LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT THIS MORNING FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LSZ321-
     322.

&&

$$

UPDATE...JAZ
NEAR TERM...JSL
SHORT TERM...JPB
LONG TERM...GILLEN
AVIATION...MLR
MARINE...JSL



000
FXUS63 KGRR 200443
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1243 AM EDT MON APR 20 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 258 PM EDT SUN APR 19 2015

A MAJOR CHANGE IN THE OVERALL WEATHER PATTERN IS ABOUT TO BEGIN. A
STRONG AND DEEPENING LOW PRESSURE SYSTEM WILL TRACK NORTHWARD
THROUGH WESTERN LOWER MICHIGAN TONIGHT BRINGING RAIN THAT MAY BE
HEAVY AT TIMES EARLY TONIGHT. AFTER THE SYSTEM MOVES NORTH OF THE
AREA LATER TONIGHT THE RAIN WILL DIMINISH TO SHOWERS BUT IT WILL
BE BREEZY. THEN SHOWERS AND BREEZY CONDITIONS WILL CONTINUE INTO
TUESDAY. BY TUESDAY NIGHT IT WILL GET COLD ENOUGH FOR SNOW TO MIX
WITH THE RAIN. THAT WILL CONTINUE INTO THURSDAY. IT WILL BE MUCH
COOLER THROUGH THIS ENTIRE PERIOD WITH HIGHS TUESDAY THROUGH
THURSDAY IN THE 40S AND LOWS NEAR FREEZING.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 258 PM EDT SUN APR 19 2015

THE PRIMARY ISSUE IS THE RAIN TONIGHT...THEN WINDY AND SHOWERS
MONDAY INTO TUESDAY. THERE IS A GOOD CHANCE OF MEASURABLE SNOW
OVER NORTHERN SECTIONS TUESDAY NIGHT.

THE DEEPENING STORM SYSTEM WILL TRACK THROUGH WESTERN LOWER
MICHIGAN TONIGHT BRINGING A PERIOD OF MODERATE TO HEAVY RAIN THAT
WILL LAST AROUND 6 HOURS IN ANY ONE PLACE. IT WILL BE BREEZY AT
FIRST BUT WINDS WILL DIMINISH TOWARD MIDNIGHT AS THE SURFACE LOW
MOVES THROUGH THE AREA.

THE RAIN EVENT TONIGHT REMAINS WELL SUPPORTED BY ALL THE MODELS.
THERE IS SOME ISSUE AS TO WHERE THE HEAVIEST RAIN WILL ACTUALLY
FALL BUT ALL AREAS GET AT LEAST A THIRD OF AN INCH AND MOST AREAS
SHOULD GET MORE THAN A HALF INCH OF RAIN TONIGHT. THIS IS ALL THE
RESULT OF UPPER WAVE THAT GOES NEGATIVE TILT OVER SOUTHWEST
MICHIGAN TONIGHT. THAT CAUSES THE SURFACE LOW TO TRACK NORTHWARD
AND DEEPEN RAPIDLY. ALSO THIS RESULTS IN A STRONG LOW LEVEL JET
(60 KNOTS)... STRONG 1000 TO 850 MOISTURE CONVERGENCE AIMED AT
SOUTHWEST LOWER MICHIGAN THIS EVENING AND CONDENSATION PRESSURE
DEFICITS NEAR ZERO MB THIS EVENING. THERE IS ALSO 40 KNOT OF WIND
PERPENDICULAR TO THE ISOTROPIC SURFACES EARLY TONIGHT... AND WE
CAN ALL ADD TO THAT PRECIPITATION WATER VALUES (1.4") NEAR 2
STANDARD DEVIATIONS FROM NORMAL AND MIXING RATIOS RISING TO NEAR 8
G/KG FROM UNDER 2 G/KG THIS MORNING. THERE IS ALSO A ZONE OF
STRONG MID-LEVEL FGEN JUST AHEAD OF THE SYSTEM AS IT MOVES THROUGH
SOUTHWEST MICHIGAN TONIGHT. BOTTOM LINE... IT WOULD BE HARD TO
IMAGINE WE WILL NOT GET RAIN OVERNIGHT.

ONCE THE LOW PASSES US THE SIGNIFICANT RAINFALL WILL END. HOWEVER
THE SECONDARY COLD FRONT AND TRAILING NORTHERN STREAM WAVE WILL
BRING ANOTHER PERIOD OF SHOWERS TO THE AREA MIDDAY MONDAY INTO
EARLY EVENING. THAT BRINGS IN THE TRULY COLDER AIR.

MONDAY NIGHT WE MAY SEE A BREAK IN THE SHOWERS EARLY ON BUT THEN
THE WRAP AROUND MOISTURE MOVES IN AND WE SEE SHOWERS THAT MAY MIX
WITH AN CHANGE TO SNOW SHOWERS BY TUESDAY NIGHT. BY THE WAY THE
SPC SOUNDING CLIMATOLOGY PAGE SHOWS THE COLDEST 850 TEMPERATURE
FOR THE DTX SOUNDING TO BE -12C ON THE 22ND. THE ECWMF SHOWS -9.8C
AT 2 PM WEDNESDAY NEAR GRR. TO SAY THE LEAST...IT WILL GET COLDER
THIS COMING WEEK!

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

UNSEASONABLY COLD WEATHER IS ANTICIPATED WEDNESDAY AND THURSDAY WITH
DEEP CYCLONIC FLOW AND COLD AIR ADVECTION WITH THE UPPER LEVEL LOW
STILL IN PLACE OVER THE NORTHERN GREAT LAKES REGION. SCATTERED RAIN
SHOWERS WILL CONTINUE AND MAY BE MIXED AT TIMES WITH WET SNOW FLAKES
ESPECIALLY OVER RELATIVELY HIGHER ELEVATIONS OF OUR NORTHERN FCST
AREA.

TEMPERATURES SHOULD MODERATE SLIGHTLY FRIDAY THROUGH THE WEEKEND BUT
WILL STILL AVERAGE SEVERAL DEGREES BELOW NORMAL. THIS AS A SFC RIDGE
BUILDS IN AND AS THE UPPER LEVEL LOW MOVES MUCH FURTHER EAST TO THE
NEW ENGLAND REGION BY THEN. THE RIDGE WILL BRING FAIR AND SEASONABLY
COOL WEATHER FRIDAY THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1242 AM EDT MON APR 20 2015

IFR CEILINGS HAVE SPREAD INTO MOST OF THE TAF SITES AT 05Z AND THE
EXPECTATION IS THAT CEILINGS WILL DIP FURTHER THROUGH THE NIGHT
INTO THE LIFR CATEGORY. POOR AVIATION CONDITIONS WILL EXIST THE
REMAINDER OF THE NIGHT AND MOST OF MONDAY MORNING. CEILINGS WILL
TRY TO LIFT TO MVFR MONDAY AFTERNOON AND POTENTIALLY BECOME VFR
MONDAY EVENING. A LOW MOVING THROUGH THE AREA IS RESPONSIBLE FOR
THE LOW CEILINGS. A LULL IN THE RAIN WILL OCCUR TONIGHT...BUT
ANOTHER ROUND OF SHOWERS ARE EXPECTED FROM MID MORNING MONDAY
THROUGH MONDAY AFTERNOON.

WINDS WILL INCREASE MONDAY AFTERNOON FROM THE SOUTHWEST AT 15 TO
30 KNOTS.


&&

.MARINE...
ISSUED AT 258 PM EDT SUN APR 19 2015

I EXTENDED THE SCA THROUGH TUESDAY AFTERNOON FOR THE ALL THE ZONES
FROM WHITEHALL SOUTH ( NORTH OF THERE WINDS WILL NOT BE AS STRONG
OVERNIGHT). AFTER THE SURFACE LOW MOVES NORTH OF MUSKEGON WINDS WILL
INCREASE TO 30 KNOTS FROM THE SOUTHWEST THEN I EXPECT 15 TO 25
KNOT WINDS MONDAY INTO TUESDAY. AS THE COLD AIR COMES IN WAVES
WILL BUILD SO WE WILL LIKELY NEED A SCA FOR THE NORTHERN TWO ZONE
GROUPS MONDAY NIGHT AND TUESDAY.


&&

.HYDROLOGY...
ISSUED AT 1114 AM EDT SUN APR 19 2015

PERIODS OF RAIN ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON AND
AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. THE LIGHTER VARIETY OF
PRECIPITATION MAY EXTENT INTO MIDWEEK. THOUGH WE WILL SEE A DECENT SOIL
SOAKING IT SHOULD NOT BE SUBSTANTIAL ENOUGH TO CREATE FLOODING
CONCERNS. GRADUAL BUT MINOR RISES ARE LIKELY...SUSPECTING THAT
THIS WOULD STAY WITHIN BANKS FOR MOST LOCATIONS. I WOULD NOT RULE
OUT A COUPLE OF SITES FLIRTING WITH ADVISORY STAGE AS WE GO INTO
TUESDAY...ESPECIALLY IF ANY MODERATE RAINFALL IS MORE PERSISTENT
WITH THE FIRST COUPLE OF ROUNDS OF MOISTURE. OTHERWISE...AREA
RIVERS ARE WELL BEHAVED THROUGH THE PERIOD.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...DUKE
HYDROLOGY...JAM
MARINE...WDM







000
FXUS63 KGRR 200443
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1243 AM EDT MON APR 20 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 258 PM EDT SUN APR 19 2015

A MAJOR CHANGE IN THE OVERALL WEATHER PATTERN IS ABOUT TO BEGIN. A
STRONG AND DEEPENING LOW PRESSURE SYSTEM WILL TRACK NORTHWARD
THROUGH WESTERN LOWER MICHIGAN TONIGHT BRINGING RAIN THAT MAY BE
HEAVY AT TIMES EARLY TONIGHT. AFTER THE SYSTEM MOVES NORTH OF THE
AREA LATER TONIGHT THE RAIN WILL DIMINISH TO SHOWERS BUT IT WILL
BE BREEZY. THEN SHOWERS AND BREEZY CONDITIONS WILL CONTINUE INTO
TUESDAY. BY TUESDAY NIGHT IT WILL GET COLD ENOUGH FOR SNOW TO MIX
WITH THE RAIN. THAT WILL CONTINUE INTO THURSDAY. IT WILL BE MUCH
COOLER THROUGH THIS ENTIRE PERIOD WITH HIGHS TUESDAY THROUGH
THURSDAY IN THE 40S AND LOWS NEAR FREEZING.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 258 PM EDT SUN APR 19 2015

THE PRIMARY ISSUE IS THE RAIN TONIGHT...THEN WINDY AND SHOWERS
MONDAY INTO TUESDAY. THERE IS A GOOD CHANCE OF MEASURABLE SNOW
OVER NORTHERN SECTIONS TUESDAY NIGHT.

THE DEEPENING STORM SYSTEM WILL TRACK THROUGH WESTERN LOWER
MICHIGAN TONIGHT BRINGING A PERIOD OF MODERATE TO HEAVY RAIN THAT
WILL LAST AROUND 6 HOURS IN ANY ONE PLACE. IT WILL BE BREEZY AT
FIRST BUT WINDS WILL DIMINISH TOWARD MIDNIGHT AS THE SURFACE LOW
MOVES THROUGH THE AREA.

THE RAIN EVENT TONIGHT REMAINS WELL SUPPORTED BY ALL THE MODELS.
THERE IS SOME ISSUE AS TO WHERE THE HEAVIEST RAIN WILL ACTUALLY
FALL BUT ALL AREAS GET AT LEAST A THIRD OF AN INCH AND MOST AREAS
SHOULD GET MORE THAN A HALF INCH OF RAIN TONIGHT. THIS IS ALL THE
RESULT OF UPPER WAVE THAT GOES NEGATIVE TILT OVER SOUTHWEST
MICHIGAN TONIGHT. THAT CAUSES THE SURFACE LOW TO TRACK NORTHWARD
AND DEEPEN RAPIDLY. ALSO THIS RESULTS IN A STRONG LOW LEVEL JET
(60 KNOTS)... STRONG 1000 TO 850 MOISTURE CONVERGENCE AIMED AT
SOUTHWEST LOWER MICHIGAN THIS EVENING AND CONDENSATION PRESSURE
DEFICITS NEAR ZERO MB THIS EVENING. THERE IS ALSO 40 KNOT OF WIND
PERPENDICULAR TO THE ISOTROPIC SURFACES EARLY TONIGHT... AND WE
CAN ALL ADD TO THAT PRECIPITATION WATER VALUES (1.4") NEAR 2
STANDARD DEVIATIONS FROM NORMAL AND MIXING RATIOS RISING TO NEAR 8
G/KG FROM UNDER 2 G/KG THIS MORNING. THERE IS ALSO A ZONE OF
STRONG MID-LEVEL FGEN JUST AHEAD OF THE SYSTEM AS IT MOVES THROUGH
SOUTHWEST MICHIGAN TONIGHT. BOTTOM LINE... IT WOULD BE HARD TO
IMAGINE WE WILL NOT GET RAIN OVERNIGHT.

ONCE THE LOW PASSES US THE SIGNIFICANT RAINFALL WILL END. HOWEVER
THE SECONDARY COLD FRONT AND TRAILING NORTHERN STREAM WAVE WILL
BRING ANOTHER PERIOD OF SHOWERS TO THE AREA MIDDAY MONDAY INTO
EARLY EVENING. THAT BRINGS IN THE TRULY COLDER AIR.

MONDAY NIGHT WE MAY SEE A BREAK IN THE SHOWERS EARLY ON BUT THEN
THE WRAP AROUND MOISTURE MOVES IN AND WE SEE SHOWERS THAT MAY MIX
WITH AN CHANGE TO SNOW SHOWERS BY TUESDAY NIGHT. BY THE WAY THE
SPC SOUNDING CLIMATOLOGY PAGE SHOWS THE COLDEST 850 TEMPERATURE
FOR THE DTX SOUNDING TO BE -12C ON THE 22ND. THE ECWMF SHOWS -9.8C
AT 2 PM WEDNESDAY NEAR GRR. TO SAY THE LEAST...IT WILL GET COLDER
THIS COMING WEEK!

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

UNSEASONABLY COLD WEATHER IS ANTICIPATED WEDNESDAY AND THURSDAY WITH
DEEP CYCLONIC FLOW AND COLD AIR ADVECTION WITH THE UPPER LEVEL LOW
STILL IN PLACE OVER THE NORTHERN GREAT LAKES REGION. SCATTERED RAIN
SHOWERS WILL CONTINUE AND MAY BE MIXED AT TIMES WITH WET SNOW FLAKES
ESPECIALLY OVER RELATIVELY HIGHER ELEVATIONS OF OUR NORTHERN FCST
AREA.

TEMPERATURES SHOULD MODERATE SLIGHTLY FRIDAY THROUGH THE WEEKEND BUT
WILL STILL AVERAGE SEVERAL DEGREES BELOW NORMAL. THIS AS A SFC RIDGE
BUILDS IN AND AS THE UPPER LEVEL LOW MOVES MUCH FURTHER EAST TO THE
NEW ENGLAND REGION BY THEN. THE RIDGE WILL BRING FAIR AND SEASONABLY
COOL WEATHER FRIDAY THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1242 AM EDT MON APR 20 2015

IFR CEILINGS HAVE SPREAD INTO MOST OF THE TAF SITES AT 05Z AND THE
EXPECTATION IS THAT CEILINGS WILL DIP FURTHER THROUGH THE NIGHT
INTO THE LIFR CATEGORY. POOR AVIATION CONDITIONS WILL EXIST THE
REMAINDER OF THE NIGHT AND MOST OF MONDAY MORNING. CEILINGS WILL
TRY TO LIFT TO MVFR MONDAY AFTERNOON AND POTENTIALLY BECOME VFR
MONDAY EVENING. A LOW MOVING THROUGH THE AREA IS RESPONSIBLE FOR
THE LOW CEILINGS. A LULL IN THE RAIN WILL OCCUR TONIGHT...BUT
ANOTHER ROUND OF SHOWERS ARE EXPECTED FROM MID MORNING MONDAY
THROUGH MONDAY AFTERNOON.

WINDS WILL INCREASE MONDAY AFTERNOON FROM THE SOUTHWEST AT 15 TO
30 KNOTS.


&&

.MARINE...
ISSUED AT 258 PM EDT SUN APR 19 2015

I EXTENDED THE SCA THROUGH TUESDAY AFTERNOON FOR THE ALL THE ZONES
FROM WHITEHALL SOUTH ( NORTH OF THERE WINDS WILL NOT BE AS STRONG
OVERNIGHT). AFTER THE SURFACE LOW MOVES NORTH OF MUSKEGON WINDS WILL
INCREASE TO 30 KNOTS FROM THE SOUTHWEST THEN I EXPECT 15 TO 25
KNOT WINDS MONDAY INTO TUESDAY. AS THE COLD AIR COMES IN WAVES
WILL BUILD SO WE WILL LIKELY NEED A SCA FOR THE NORTHERN TWO ZONE
GROUPS MONDAY NIGHT AND TUESDAY.


&&

.HYDROLOGY...
ISSUED AT 1114 AM EDT SUN APR 19 2015

PERIODS OF RAIN ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON AND
AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. THE LIGHTER VARIETY OF
PRECIPITATION MAY EXTENT INTO MIDWEEK. THOUGH WE WILL SEE A DECENT SOIL
SOAKING IT SHOULD NOT BE SUBSTANTIAL ENOUGH TO CREATE FLOODING
CONCERNS. GRADUAL BUT MINOR RISES ARE LIKELY...SUSPECTING THAT
THIS WOULD STAY WITHIN BANKS FOR MOST LOCATIONS. I WOULD NOT RULE
OUT A COUPLE OF SITES FLIRTING WITH ADVISORY STAGE AS WE GO INTO
TUESDAY...ESPECIALLY IF ANY MODERATE RAINFALL IS MORE PERSISTENT
WITH THE FIRST COUPLE OF ROUNDS OF MOISTURE. OTHERWISE...AREA
RIVERS ARE WELL BEHAVED THROUGH THE PERIOD.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...DUKE
HYDROLOGY...JAM
MARINE...WDM






000
FXUS63 KDTX 200351
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1151 PM EDT SUN APR 19 2015


.AVIATION...

LOW PRESSURE WILL ADVANCE ACROSS WRN LOWER MI OVERNIGHT INTO MON
MORNING. PERIODIC SHOWERS WILL PERSIST DURING MUCH OF THE OVERNIGHT.
CEILINGS WILL CONTINUE TO TREND LOWER AS THIS LOW PRESSURE SYSTEM
DRIVES ADDITIONAL LOW LEVEL MOISTURE INTO SE MI. GIVEN UPSTREAM
OBSERVATIONS...FLUCTUATIONS BETWEEN LOW END MVFR AND IFR LOOK TO
PREVAIL AT LEAST UNTIL THE PASSAGE OF THE SFC WARM FRONT BETWEEN 09Z
AND 11Z. WINDS WILL VEER TOWARD THE S-SW WITH THE PASSAGE OF THIS
FRONT AND CEILINGS MAY ACTUALLY IMPROVE A LITTLE AS THE WARM SECTOR
SLIDES INTO SE MI. THE GRADIENT ASSOCIATED WITH THIS SYSTEM WILL
MAINTAIN GUSTY WINDS THROUGH MON AFTERNOON...WITH FREQUENT GUSTS
OVER 20 KNOTS EXPECTED.

FOR DTW...THE WARM FRONT WILL MOVE ACROSS METRO AROUND 09Z. WIND
GUSTS WITHIN THE S-SW FLOW OF THE WARM SECTOR ARE LIKELY TO TOP 25
KNOTS WELL INTO MON AFTERNOON.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS AOB 5KFT TONIGHT AND MONDAY.

* LOW IN THUNDERSTORMS TONIGHT AND MONDAY AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 951 PM EDT SUN APR 19 2015

UPDATE...

THE REGION OF RAIN ASSOCIATED WITH A GOOD MOISTURE SURGE WITHIN A
WARM AIR ADVECTION REGIME HAS BEEN LIFTING NORTHWARD RATHER
RAPIDLY ACROSS THE FORECAST AREA. AS OF 945 PM...THE BACK EDGE OF
THE STEADIER RAINFALL WAS ALREADY LIFTING ACROSS MONROE/LENAWEE
COUNTIES. AT THIS PACE...THE WIDESPREAD RAIN SHOULD LIFT NORTH OF
THE FORECAST AREA BY 2 AM. UPSTREAM RADAR DOES HOWEVER SHOW
ADDITIONAL SHOWERS AND FEW THUNDERSTORMS ACROSS SRN INDIANA AND
OHIO...LIFTING NORTHWARD. THESE SHOWERS ARE BEING AIDED BY LIFT
ALONG A MID LEVEL SHORT WAVE FEATURE AND ARE ALONG A SECONDARY LOW
LEVEL THETA E PLUME ALIGNED ALONG A SURFACE WARM FRONT. THESE
FEATURES WILL LIFT NORTHWARD INTO SE MI OVERNIGHT AND WILL STILL
SUPPORT SCT TO NMRS POPS. SO IN SHORT...THE CURRENT FORECAST
WHICH FEATURES CATEGORICAL RAIN TRANSITIONING TO SCT-NMRS SHOWERS
OVERNIGHT STILL LOOKS IN LINE. A UPDATE WILL BE ISSUED LATER THIS
EVENING SIMPLY TO ADJUST TIMING. IN LIGHT OF CURRENT RADAR
RAINFALL ESTIMATES...FORECAST QPF MAY BE TAKEN DOWN A LITTLE AS
WELL.

PREV DISCUSSION...ISSUED 356 PM EDT SUN APR 19 2015

SHORT TERM...TONIGHT

THE ARC OF SHOWER ACTIVITY FORCED ON AN INITIAL SURGE/GRADIENT OF
850-700MB MOISTURE HAS STRUGGLED FROM A VIGOR PERSPECTIVE DUE TO A
LACK OF INSTABILITY. WITH SHOWERS WORKING UP THE FRONTAL SLOPE AS IT
TRACKS NORTHWARD...EXPECT THE WEAK NATURE TO CONTINUE.

THE MAIN BAND OF SYNOPTIC FORCING AND WIDESPREAD RAIN ACTIVITY WILL
LIFT ACROSS THE OHIO AND MICHIGAN BORDER AROUND 21Z. REGIONAL MOSAIC
AS OF 19Z... SHOWS THE MIDLEVELS SATURATING SOUTH OF TOLEDO. REALLY
A TREMENDOUS AMOUNT OF SYNOPTIC SCALE SUPPORT FOR LIFT AND
PRECIPITATION GENERATION TONIGHT AS SOUTHEASTERN MICHIGAN REMAINS
FAVORABLY POSITIONED AHEAD OF A HIGH AMPLITUDE WARM SECTOR
STRUCTURE AND OPTIMAL WARM AIR ADVECTION. EVERYTHING APPEARS TO BE
LINING UP FROM A FORCING STANDPOINT FOR A FAVORABLE PERIOD OF
WIDESPREAD RAIN INCLUDING A POTENTIAL FOR HEAVY RAINFALL.
SPECIFICALLY...LARGE BULLSEYE OF 1000-500MB HEIGHT FALLS...LINKAGE
OF RIGHT NOSE OF LOW LEVEL JET AXIS WITH RIGHT ENTRANCE REGION
DYNAMICS ALOFT...AND A DIRECT HIT FROM A SECONDARY VORTICITY
MAXIMUM. NWP SUPPORTS THIS SECONDARY VORTICITY MAXIMUM BECOMING
ORGANIZED/STRENGTHENING NEAR LOUISVILLE NOW AND LIFTING INTO FAR
SOUTHEASTERN MICHIGAN BETWEEN 00-03Z. NAM REALLY BITES ON THIS
FEATURE SHOWING DEPICTIONS OF A PSEUDO SHARS TYPE RESPONSE AND
HIGH AMOUNTS OF 3HR QPF. BROAD NATIONAL MOSAIC OF REFLECTIVITY
ALONG WITH SATELLITE IMAGERY OF CLEARING/DESTABILIZING STRAIGHT
INTO CENTRAL KENTUCKY SUPPORTS THIS STRONG SOLUTION OF THE
SECONDARY VORTICITY MAXIMUM. THUS...THE EARLIER FORECAST OF
FORECASTING QPF AMOUNTS OF UPWARDS OF 1.00 INCH FOR FAR
SOUTHEASTERN MICHIGAN INCLUDING THE DETROIT METRO APPEARS
REASONABLE. THERE AT LEAST REMAINS SOME POTENTIAL THAT THIS DRY
AIR/SLOT COULD WORK NORTHWARD AT A CRITICAL TRAJECTORY AND CAUSE
HEAVY PRECIPITATION TO DEFLECT AWAY FROM THE CWA. CONFIDENCE IN
PROJECTING THAT OUT IS LOW. WHILE FORECASTED QPF AMOUNTS ARE
RELATIVELY HIGH FROM AN EVENT STANDPOINT...THE STEADY NORTHWARD
PROGRESSION OF SHOWERS/EMBEDDED THUNDER WILL LIMIT THE CONCERN FOR
FLOODING.

LONG TERM...

STRONG LOW PRESSURE WILL CONTINUE TO DEEPEN AS IT LIFTS NORTHWARD
THROUGH NORTHERN LOWER MICHIGAN INTO ONTARIO ON MONDAY. MODELS HAVE
TRENDED SLIGHTLY SLOWLY AND FURTHER WEST WITH THE TRACK OF THIS
SYSTEM...AND THIS WILL MOSTLY LIKELY HAVE SOME NOTABLE IMPLICATIONS
TO THE GOING FORECAST. AS SUCH...HAVE MADE A FEW ADJUSTMENTS FOR
THIS PACKAGE.

THE "NEW" CONSENSUS TRACK FORECAST WILL ESSENTIALLY DELAY THE COLD
FRONTAL PASSAGE THROUGH THE AREA UNTIL LATE AFTERNOON AND ALLOW FOR
TEMPERATURES TO CLIMB WELL INTO THE 60S OVER A GOOD PORTION OF THE
AREA. THIS...IN TURN...WILL ALLOW FOR SOME DESTABILIZATION AS SBCAPE
VALUES CLIMB TO AROUND 500 J/KG BY AFTERNOON. THIS SHOULD ALLOW FOR
MORE VIGOROUS CONVECTION ALONG THE COLD FRONT WITH THE POTENTIAL FOR
HAIL INCREASING AS FREEZING LEVELS DROP BELOW 7000-8000 FEET AS COLD
AIR WRAP AROUND THE UPPER CIRCULATION.

IN ADDITION...THIS ACTIVITY WILL LIKELY PRODUCE SOME GUSTY WINDS AS
DEEP SWATH OF 35 TO 40 KT SOUTHWEST FLOW OVERSPREADS THE AREA. EVEN
OUTSIDE OF STORMS...WIND GUSTS WILL LIKELY REACH 35 MPH AT TIMES BY
AFTERNOON AND HAVE UPPED THE OVERALL FORECAST WINDS A FAIR AMOUNT.
WHILE WIDESPREAD STRONG STORMS ARE PROBABLY NOT TOO LIKELY...A FEW
WILL CERTAINLY BECOME A BIT ROBUST AS FORCING ALONG THE COLD FRONT
HELPS FOCUS THE MARGINAL INSTABILITY THAT IS ABLE TO BUILD OVER
PARTS OF THE AREA.

CONDITIONS WILL QUIET FROM MID EVENING INTO TUESDAY AS THE LOW LIFTS
TO NEAR JAMES BAY AND STALLS. THAT SAID...CONDITIONS WILL REMAIN
RATHER UNSETTLED INTO THE TUESDAY AND TUESDAY NIGHT PERIOD AS THIS
LOW ONLY GRADUALLY WEAKENS. EXPECT COOLER TEMPERATURES AND CONTINUE
GUSTY WINDS WITH SCATTERED RAIN SHOWERS DOTTING THE REGION...MAINLY
IN THE TUESDAY AFTERNOON PERIOD DURING THE DIURNAL TEMPERATURE AND
INSTABILITY MAX. DOWNSLOPING WEST/SOUTHWEST FLOW SHOULD ALLOW METRO
DETROIT AND SURROUNDING AREAS TO CLIMB INTO THE MID 50S DESPITE THE
MUCH COLDER AIRMASS...BUT STILL EXPECT LOWS WELL INTO THE 30S BY
TUESDAY NIGHT AS THE COLD AIRMASS DEEPENS OVER THE AREA.

EXTENDED FORECAST STARTING WEDNESDAY AND INTO NEXT WEEKEND WILL BE
RELATIVELY QUIET AS FAR AS PRECIPITATION GOES WITH BELOW NORMAL
TEMPERATURES.  COOLER AIR WILL CONTINUE TO FILTER INTO THE REGION AS
THE GREAT LAKES RESIDES IN THE PERSISTENT LONGWAVE TROUGHING.  WHILE
THERE WILL BE SLIGHT PRECIPITATION CHANCES WHILE THE REGION RESIDES
IN THE TROUGH...THE CAVEAT IS THE LACK OF MOISTURE THAT WILL BE
AVAILABLE.  RIDGING DOES NOT LOOK TO START BUILDING INTO THE WESTERN
GREAT LAKES REGION UNTIL THE END OF THE FORECAST PERIOD.

MARINE...

EAST FLOW WILL GRADUALLY BECOME SOUTHEAST TONIGHT AS DEEPENING LOW
PRESSURE PUSHES A WARM FRONT THROUGH THE AREA. DURING THIS TIME
FRAME...EXPECT STEADILY INCREASING WIND SPEEDS WHICH WILL ALLOW
WAVES TO BUILD. AS THIS LOW PASSES INTO THE NORTHERN GREAT LAKES
MONDAY...WINDS REMAIN GUSTY AND VEER TO THE SOUTH AND THEN SOUTHWEST
AS A COLD FRONT SWEEPS AROUND THE BASE OF THE EXITING LOW PRESSURE.
SMALL CRAFT ADVISORIES WILL CONTINUE INTO MONDAY. WHILE A FEW GUSTS
MAY APPROACH GALE FORCE...THE MARINE LAYER LOOKS TO BE FAIRLY STABLE
WHICH WILL LIMIT THIS POTENTIAL. WINDS WILL SUBSIDE TO SOME EXTENT
FROM MONDAY NIGHT INTO TUESDAY AS THE LOW STALLS NEAR JAMES BAY AND
BEGINS TO SLOWLY WEAKEN.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR LHZ421-422-441>443.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR LEZ444.

&&

$$

AVIATION.....SC
UPDATE.......SC
SHORT TERM...CB
LONG TERM....DG/SS
MARINE.......DG


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).




000
FXUS63 KDTX 200151
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
951 PM EDT SUN APR 19 2015

.UPDATE...

THE REGION OF RAIN ASSOCIATED WITH A GOOD MOISTURE SURGE WITHIN A
WARM AIR ADVECTION REGIME HAS BEEN LIFTING NORTHWARD RATHER
RAPIDLY ACROSS THE FORECAST AREA. AS OF 945 PM...THE BACK EDGE OF
THE STEADIER RAINFALL WAS ALREADY LIFTING ACROSS MONROE/LENAWEE
COUNTIES. AT THIS PACE...THE WIDESPREAD RAIN SHOULD LIFT NORTH OF
THE FORECAST AREA BY 2 AM. UPSTREAM RADAR DOES HOWEVER SHOW
ADDITIONAL SHOWERS AND FEW THUNDERSTORMS ACROSS SRN INDIANA AND
OHIO...LIFTING NORTHWARD. THESE SHOWERS ARE BEING AIDED BY LIFT
ALONG A MID LEVEL SHORT WAVE FEATURE AND ARE ALONG A SECONDARY LOW
LEVEL THETA E PLUME ALIGNED ALONG A SURFACE WARM FRONT. THESE
FEATURES WILL LIFT NORTHWARD INTO SE MI OVERNIGHT AND WILL STILL
SUPPORT SCT TO NMRS POPS. SO IN SHORT...THE CURRENT FORECAST
WHICH FEATURES CATEGORICAL RAIN TRANSITIONING TO SCT-NMRS SHOWERS
OVERNIGHT STILL LOOKS IN LINE. A UPDATE WILL BE ISSUED LATER THIS
EVENING SIMPLY TO ADJUST TIMING. IN LIGHT OF CURRENT RADAR
RAINFALL ESTIMATES...FORECAST QPF MAY BE TAKEN DOWN A LITTLE AS
WELL.

&&

.AVIATION...ISSUED 700 PM EDT SUN APR 19 2015

RAIN WILL CONTINUE EXPANDING ACROSS SE MI AND WILL OVERSPREAD THE
TERMINALS BY 00Z. EASTERLY WINDS HAVE BEEN SUSTAINING LOW LEVEL DRY
AIR WHICH IN TURN HAS HELD CEILINGS UP. A SUBSTANTIAL AMOUNT OF
MOISTURE ADVECTION DURING THE EVENING AND OVERNIGHT ALONG WITH
INCREASING INTENSITY OF RAINFALL WILL HOWEVER LEAD TO A STEADY
LOWERING TREND IN CEILINGS THIS EVENING. IFR CONDITIONS ARE EXPECT
TO DEVELOP EITHER LATE THIS EVENING OR EARLY IN THE OVERNIGHT
PERIOD. UPSTREAM OBSERVATIONS DO HOWEVER SUGGEST THERE IS LIKELY TO
BE A GOOD DEAL OF VARIABILITY IN CEILING HEIGHTS. THIS RAIN AND
MOISTURE THAT IS LIFTING ACROSS THE AREA IS ASSOCIATED WITH A LOW
PRESSURE SYSTEM OVER INDIANA. THIS LOW WILL LIFT ACROSS WESTERN
LOWER MI TONIGHT. EVEN WITH THE RAINFALL...THE SFC GRADIENT SHOULD
SUSTAIN SOME DEGREE OF GUSTINESS TO THE WINDS TONIGHT /POSSIBLY
TOPPING 20 KNOTS AT TIMES/. A WARM FRONT ASSOCIATED WITH THE SFC LOW
IS FORECAST TO LIFT NORTH ACROSS SE MI BETWEEN 09Z AND 12Z. THE
PASSAGE OF THIS FRONT WILL VEER WINDS TO THE SOUTH AND MAY ACTUALLY
LEAD TO SOME LIFTING OF CLOUD BASES AS THE WARM SECTOR NUDGES INTO
THE AREA.

FOR DTW...THE PEAK IN RAINFALL INTENSITY IS EXPECTED TO OCCUR
BETWEEN 02Z AND 05Z...WHERE SOME PERIODIC HEAVY RAINFALL IS
POSSIBLE. WHILE CEILING HEIGHTS WILL FLUCTUATE A GOOD DEAL...THE
OVERALL TREND HEADING INTO THE OVERNIGHT WILL BE FOR THE DEVELOPMENT
OF IFR CONDITIONS.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS AOB 5KFT TONIGHT AND MONDAY.

* LOW IN THUNDERSTORMS TONIGHT AND MONDAY.

&&

.PREV DISCUSSION...ISSUED 356 PM EDT SUN APR 19 2015

SHORT TERM...TONIGHT

THE ARC OF SHOWER ACTIVITY FORCED ON AN INITIAL SURGE/GRADIENT OF
850-700MB MOISTURE HAS STRUGGLED FROM A VIGOR PERSPECTIVE DUE TO A
LACK OF INSTABILITY. WITH SHOWERS WORKING UP THE FRONTAL SLOPE AS IT
TRACKS NORTHWARD...EXPECT THE WEAK NATURE TO CONTINUE.

THE MAIN BAND OF SYNOPTIC FORCING AND WIDESPREAD RAIN ACTIVITY WILL
LIFT ACROSS THE OHIO AND MICHIGAN BORDER AROUND 21Z. REGIONAL MOSAIC
AS OF 19Z... SHOWS THE MIDLEVELS SATURATING SOUTH OF TOLEDO. REALLY
A TREMENDOUS AMOUNT OF SYNOPTIC SCALE SUPPORT FOR LIFT AND
PRECIPITATION GENERATION TONIGHT AS SOUTHEASTERN MICHIGAN REMAINS
FAVORABLY POSITIONED AHEAD OF A HIGH AMPLITUDE WARM SECTOR
STRUCTURE AND OPTIMAL WARM AIR ADVECTION. EVERYTHING APPEARS TO BE
LINING UP FROM A FORCING STANDPOINT FOR A FAVORABLE PERIOD OF
WIDESPREAD RAIN INCLUDING A POTENTIAL FOR HEAVY RAINFALL.
SPECIFICALLY...LARGE BULLSEYE OF 1000-500MB HEIGHT FALLS...LINKAGE
OF RIGHT NOSE OF LOW LEVEL JET AXIS WITH RIGHT ENTRANCE REGION
DYNAMICS ALOFT...AND A DIRECT HIT FROM A SECONDARY VORTICITY
MAXIMUM. NWP SUPPORTS THIS SECONDARY VORTICITY MAXIMUM BECOMING
ORGANIZED/STRENGTHENING NEAR LOUISVILLE NOW AND LIFTING INTO FAR
SOUTHEASTERN MICHIGAN BETWEEN 00-03Z. NAM REALLY BITES ON THIS
FEATURE SHOWING DEPICTIONS OF A PSEUDO SHARS TYPE RESPONSE AND
HIGH AMOUNTS OF 3HR QPF. BROAD NATIONAL MOSAIC OF REFLECTIVITY
ALONG WITH SATELLITE IMAGERY OF CLEARING/DESTABILIZING STRAIGHT
INTO CENTRAL KENTUCKY SUPPORTS THIS STRONG SOLUTION OF THE
SECONDARY VORTICITY MAXIMUM. THUS...THE EARLIER FORECAST OF
FORECASTING QPF AMOUNTS OF UPWARDS OF 1.00 INCH FOR FAR
SOUTHEASTERN MICHIGAN INCLUDING THE DETROIT METRO APPEARS
REASONABLE. THERE AT LEAST REMAINS SOME POTENTIAL THAT THIS DRY
AIR/SLOT COULD WORK NORTHWARD AT A CRITICAL TRAJECTORY AND CAUSE
HEAVY PRECIPITATION TO DEFLECT AWAY FROM THE CWA. CONFIDENCE IN
PROJECTING THAT OUT IS LOW. WHILE FORECASTED QPF AMOUNTS ARE
RELATIVELY HIGH FROM AN EVENT STANDPOINT...THE STEADY NORTHWARD
PROGRESSION OF SHOWERS/EMBEDDED THUNDER WILL LIMIT THE CONCERN FOR
FLOODING.

LONG TERM...

STRONG LOW PRESSURE WILL CONTINUE TO DEEPEN AS IT LIFTS NORTHWARD
THROUGH NORTHERN LOWER MICHIGAN INTO ONTARIO ON MONDAY. MODELS HAVE
TRENDED SLIGHTLY SLOWLY AND FURTHER WEST WITH THE TRACK OF THIS
SYSTEM...AND THIS WILL MOSTLY LIKELY HAVE SOME NOTABLE IMPLICATIONS
TO THE GOING FORECAST. AS SUCH...HAVE MADE A FEW ADJUSTMENTS FOR
THIS PACKAGE.

THE "NEW" CONSENSUS TRACK FORECAST WILL ESSENTIALLY DELAY THE COLD
FRONTAL PASSAGE THROUGH THE AREA UNTIL LATE AFTERNOON AND ALLOW FOR
TEMPERATURES TO CLIMB WELL INTO THE 60S OVER A GOOD PORTION OF THE
AREA. THIS...IN TURN...WILL ALLOW FOR SOME DESTABILIZATION AS SBCAPE
VALUES CLIMB TO AROUND 500 J/KG BY AFTERNOON. THIS SHOULD ALLOW FOR
MORE VIGOROUS CONVECTION ALONG THE COLD FRONT WITH THE POTENTIAL FOR
HAIL INCREASING AS FREEZING LEVELS DROP BELOW 7000-8000 FEET AS COLD
AIR WRAP AROUND THE UPPER CIRCULATION.

IN ADDITION...THIS ACTIVITY WILL LIKELY PRODUCE SOME GUSTY WINDS AS
DEEP SWATH OF 35 TO 40 KT SOUTHWEST FLOW OVERSPREADS THE AREA. EVEN
OUTSIDE OF STORMS...WIND GUSTS WILL LIKELY REACH 35 MPH AT TIMES BY
AFTERNOON AND HAVE UPPED THE OVERALL FORECAST WINDS A FAIR AMOUNT.
WHILE WIDESPREAD STRONG STORMS ARE PROBABLY NOT TOO LIKELY...A FEW
WILL CERTAINLY BECOME A BIT ROBUST AS FORCING ALONG THE COLD FRONT
HELPS FOCUS THE MARGINAL INSTABILITY THAT IS ABLE TO BUILD OVER
PARTS OF THE AREA.

CONDITIONS WILL QUIET FROM MID EVENING INTO TUESDAY AS THE LOW LIFTS
TO NEAR JAMES BAY AND STALLS. THAT SAID...CONDITIONS WILL REMAIN
RATHER UNSETTLED INTO THE TUESDAY AND TUESDAY NIGHT PERIOD AS THIS
LOW ONLY GRADUALLY WEAKENS. EXPECT COOLER TEMPERATURES AND CONTINUE
GUSTY WINDS WITH SCATTERED RAIN SHOWERS DOTTING THE REGION...MAINLY
IN THE TUESDAY AFTERNOON PERIOD DURING THE DIURNAL TEMPERATURE AND
INSTABILITY MAX. DOWNSLOPING WEST/SOUTHWEST FLOW SHOULD ALLOW METRO
DETROIT AND SURROUNDING AREAS TO CLIMB INTO THE MID 50S DESPITE THE
MUCH COLDER AIRMASS...BUT STILL EXPECT LOWS WELL INTO THE 30S BY
TUESDAY NIGHT AS THE COLD AIRMASS DEEPENS OVER THE AREA.

EXTENDED FORECAST STARTING WEDNESDAY AND INTO NEXT WEEKEND WILL BE
RELATIVELY QUIET AS FAR AS PRECIPITATION GOES WITH BELOW NORMAL
TEMPERATURES.  COOLER AIR WILL CONTINUE TO FILTER INTO THE REGION AS
THE GREAT LAKES RESIDES IN THE PERSISTENT LONGWAVE TROUGHING.  WHILE
THERE WILL BE SLIGHT PRECIPITATION CHANCES WHILE THE REGION RESIDES
IN THE TROUGH...THE CAVEAT IS THE LACK OF MOISTURE THAT WILL BE
AVAILABLE.  RIDGING DOES NOT LOOK TO START BUILDING INTO THE WESTERN
GREAT LAKES REGION UNTIL THE END OF THE FORECAST PERIOD.

MARINE...

EAST FLOW WILL GRADUALLY BECOME SOUTHEAST TONIGHT AS DEEPENING LOW
PRESSURE PUSHES A WARM FRONT THROUGH THE AREA. DURING THIS TIME
FRAME...EXPECT STEADILY INCREASING WIND SPEEDS WHICH WILL ALLOW
WAVES TO BUILD. AS THIS LOW PASSES INTO THE NORTHERN GREAT LAKES
MONDAY...WINDS REMAIN GUSTY AND VEER TO THE SOUTH AND THEN SOUTHWEST
AS A COLD FRONT SWEEPS AROUND THE BASE OF THE EXITING LOW PRESSURE.
SMALL CRAFT ADVISORIES WILL CONTINUE INTO MONDAY. WHILE A FEW GUSTS
MAY APPROACH GALE FORCE...THE MARINE LAYER LOOKS TO BE FAIRLY STABLE
WHICH WILL LIMIT THIS POTENTIAL. WINDS WILL SUBSIDE TO SOME EXTENT
FROM MONDAY NIGHT INTO TUESDAY AS THE LOW STALLS NEAR JAMES BAY AND
BEGINS TO SLOWLY WEAKEN.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR LHZ441>443.

     SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR LHZ421-422.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR LEZ444.

&&

$$

UPDATE.......SC
AVIATION.....SC
SHORT TERM...CB
LONG TERM....DG/SS
MARINE.......DG


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).



000
FXUS63 KAPX 200135
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
935 PM EDT SUN APR 19 2015

.UPDATE...
ISSUED AT 935 PM EDT SUN APR 19 2015

IT HAS BEEN IN NO HURRY...BUT WIDESPREAD RAIN IS MAKING STEADY
INROADS NORTHWARD ACROSS CENTRAL LOWER MI. LEADING EDGE IS NOW A
BIT NORTH OF GLADWIN/STANDISH. AHEAD OF THIS...A BAND OF -SHRA
HAS ADVANCED TO A FRANKFORT-GLR-PRESQUE ISLE LT LINE. HAVE BEEN
ADJUSTING TIMING OF PRECIP ONSET...MAINLY TO SLOW THINGS DOWN A
BIT. BUT THE MAIN GIST OF THE FORECAST...I.E. EVERYONE EVENTUALLY
GETS WET TONIGHT...IS FINE.

&&

.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 402 PM EDT SUN APR 19 2015

HIGH IMPACT WEATHER: MINIMAL

FORECAST CHALLENGE: TIMING OF THE RAIN TONIGHT.

OVERVIEW...WHILE THE MOISTURE HAS BEEN INCREASING ALONG THE LAKE
HURON SHORE AND INLAND OF NE LOWER, NW LOWER HAS BEEN DRYING OUT
WITH A GOOD PORTION OF THE AREA WEST OF I-75 HAVING FALLEN BELOW
25%. IN E UPPER, THE RH HAS BEEN BETWEEN 40% AND 45%. WHAT THIS IS
DOING IS DELAYING THE RAIN SHIELD`S TRAVEL NORTH, WHICH HAD JUST
MADE IT TO THE MICHIGAN/INDIANA BORDER AROUND 19Z. USING THE TIMING
TOOL ON AWIPS, IT LOOKS LIKE THE RAIN SHOULD GET TO THE M-55
CORRIDOR AROUND 23Z, M-72 AROUND 00Z, M-32 AROUND 01Z, AND THE
STRAIT BETWEEN 02Z AND 03Z.

DETAILS FOR TONIGHT...AS WAS MENTIONED, TRYING TO TIME THIS SYSTEM
WITH THE DRY AIR IN THE LOWER LEVELS IS MADDENING. THE QUESTION
ISN`T IF THE AIR WILL LEAVE, BUT WHEN AS THE SFC LOW WILL, AS IT
MOVES UP FROM THE MID-MISSISSIPPI VALLEY, OVERWHELM WITH DRY AIR
WITH ITS MOISTURE, AND ALLOW THE RAIN TO FALL ALL THE WAY TO THE
SFC. HOWEVER, ONCE THE RAIN STARTS, IT WILL FALL THROUGH THE NIGHT
AS THE SFC NORTH OVER THE WESTERN PART OF THE STATE BETWEEN 06Z AND
12Z. THIS SFC LOW AND ASSOCIATED 500 MB SHORTWAVE TROUGH AND 50 KNOT
SPEED MAX THAT MOVES OVER THE STATE, OVER THE WARM FRONT. WITH THE
PWAT AROUND 1.0" OVERNIGHT OVER THE FORECAST AREA, WILL EXPECT
THAT A DECENT STEADY RAIN WILL RESULT.

&&

.SHORT TERM...(MONDAY THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

...SHOWERY/COOL/UNSETTLED THROUGH MIDWEEK...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: WELL-DEFINED SPLIT FLOW PATTERN FROM THE
END OF LAST WEEK NOW CONSOLIDATING AS NORTHERN BRANCH SHORT WAVE
TROUGH DIGS SOUTHEAST FROM WESTERN CANADA AND SCOOPS UP PESKY
SOUTHERN BRANCH VORTEX THAT HAS BEEN SPINNING ACROSS THE GREAT
BASIN/SOUTHERN ROCKIES SINCE THE MIDDLE OF LAST WEEK.  POSITIVE
PACIFIC TELECONNECTIONS LEADING TO A MORE AMPLIFIED PATTERN (BIG
TROUGH EAST OF THE DATELINE WITH +PNA RIDGING ALONG THE WEST COAST
OF NORTH AMERICA.  THIS CONSOLIDATING CENTRAL NORTH AMERICAN TROUGH
WILL BECOME THE PREDOMINANT WEATHER FEATURE THIS WEEK AS IT TAKES UP
RESIDENCE WITH REX BLOCKING ALONG THE WEST COAST...WITH AN UPPER LOW
EVENTUALLY PARKING ITSELF OVER THE GREAT LAKES BY MIDWEEK.

SOUTHERN BRANCH DISTURBANCE LOOKS TO COME OUT IN TWO PIECES
MONDAY...WHILE CLOSED CIRCULATION ALOFT DEVELOPS OVER NORTHWEST
ONTARIO/UPPER MIDWEST.  UPPER LOW THEN SETTLES OVER LAKE SUPERIOR
TUESDAY AND HANGS IN THROUGH MIDWEEK.  AT THE SURFACE...LEAD
SOUTHERN BRANCH SHORT WAVE TROUGH HAS AN ASSOCIATED SURFACE LOW OVER
THE MID MISSISSIPPI VALLEY THAT IS FORECAST TO DEEPEN AND LIFT NORTH
INTO LOWER MICHIGAN BY MONDAY MORNING...PROBABLY BELOW 990MB WHICH
IS PRETTY SIGNIFICANT BY MID-APRIL STANDARDS.  THIS LOW WILL PULL
COOLER AIR INTO MICHIGAN STARTING MONDAY NIGHT...CYCLONIC FLOW
LINGERS INTO MIDWEEK.

PRIMARY FORECAST CONCERNS: VARYING PRECIPITATION CHANCES THROUGH
MIDWEEK...AS WELL AS PRECIPITATION TYPE.

MONDAY...12Z SOUNDINGS AND GOES SOUNDER IMAGERY SHOWS A NICE SURGE
OF MOISTURE COMING UP ACROSS THE SOUTHEASTERN STATES (1.00-1.50 INCH
PRECIPITABLE WATER) WHICH IS PUSHING A LARGE ARE OF RAIN NORTHWARD
ACROSS THE OHIO VALLEY...AND EVENTUALLY INTO MICHIGAN TONIGHT/MONDAY
MORNING.  THIS WILL PUSH THROUGH THE FORECAST AREA MONDAY MORNING
(PERHAPS FAIRLY QUICKLY) WITH MID LEVEL DRYING (POSSIBLY TAPERING
OFF TO A PERIOD OF DRIZZLE).  SURFACE LOW TRACKS ACROSS NORTHERN
LOWER MONDAY MORNING...BEHIND THAT A LINGERING BAND OF DEFORMATION/
FRONTOGENETIC PRECIPITATION WILL ROTATE IN FROM THE WEST DURING THE
AFTERNOON HOURS.  IN ADDITION...COULD SEE SOME CONVECTIVE PRECIP
CLOSE TO THE SOUTHEAST PORTION OF THE FORECAST AREA DURING THE LATE
MORNING/AFTERNOON WITH SOME ELEVATED INSTABILITY (TQ INDICES
POTENTIALLY IN THE 16-20C RANGE NEAR LOW LEVEL THETA-E RIDGE) AND
SECOND PIECE OF SOUTHERN BRANCH ENERGY SWINGING NORTHEAST ACROSS THE
LOWER PENINSULA.  MORE LIKELY THIS ACTIVITY WOULD OCCUR ACROSS THE
THUMB INTO LAKE HURON...BUT MAY BE CLOSE.  WILL NOT TRY AND VARY
PRECIP PROBABILITIES IN THE FORECAST GRIDS TO ACCOUNT FOR TIMING OF
VARIOUS WAVES OF PRECIPITATION (AS IT WILL BE WRONG ANYHOW)...WITH A
GENERIC HIGH LIKELY/CATEGORICAL POP THROUGH THE DAY SUFFICIENT FOR
NOW. AS LONG AS INITIAL AREA OF RAIN SCOOTS NORTH QUICKLY MONDAY
MORNING... NOT EXPECT A LOT OF RAINFALL IN THE 12Z-00Z TIME FRAME
(UNLESS CONVECTION CAN CLIP FAR EASTERN ZONES DURING THE AFTERNOON)
WITH FORECAST 12H QPF UNDER 0.25 INCH THOUGH COULD BE HIGHER ACROSS
EASTERN UPPER/FAR NORTHEAST LOWER GIVEN THE ABOVE CAVEATS.  TRACK OF
THE LOW RIGHT ACROSS LOWER MICHIGAN WILL LEAD TO SOME TRICKY
TEMPERATURE FORECASTS...IN GENERAL COOLER WEST AND WARMER EAST WITH
FALLING TEMPERATURES DURING THE MID/LATE AFTERNOON AS WINDS SWITCH
AROUND TO A MORE WESTERLY COMPONENT.

WHAT REMAINS OF DEFORMATION PRECIP BAND EXPECTED TO LIFT NORTHEAST
ACROSS NORTHERN MICHIGAN MONDAY EVENING...AFTER THAT MAY BE ON THE
QUIET SIDE OVERNIGHT AND WILL CONFINE POPS TO THE EVENING HOURS.
PRECIP TYPE MAY BE IN QUESTION ACROSS EASTERN UPPER AS DEPTH OF
SURFACE BASED WARM LAYER SHRINKS.  AS NORTHERN BRANCH SHORT WAVE
TROUGHS START GETTING INVOLVED IN THE FORECAST SCENARIO CAN`T RULE
OUT SOME ADDITIONAL SHOWERS DEVELOPING OVERNIGHT INTO TUESDAY
MORNING BUT NOT CONVINCED THE PROBABILITY RISES TO A SUFFICIENT
LEVEL TO INCLUDE IN THE FORECAST...WILL LEAVE IT OUT AND MAINTAIN
CONTINUITY.

TUESDAY...DEEP LAYER CYCLONIC FLOW ACROSS THE UPPER LAKES SPELLS
UNSETTLED AND NOT WARM WEATHER FOR TUESDAY.  DEEP MOISTURE WILL
ROTATE AROUND THE SOUTH SIDE OF THE UPPER LOW...AND COOL
TEMPERATURES ALOFT (AT OR BELOW -30C/500MB) WILL ADD A DIURNAL
COMPONENT TO SUPPORT SHOWERS...AND GIVEN COOL TEMPERATURES PRECIP
COULD FALL AS RAIN/SNOW/GRAUPEL.  GUSTY SOUTHWEST WINDS (20-30MPH
GUSTS PROBABLE NORTHERN LOWER) WON`T MAKE IT FEEL ANY WARMER...WITH
AFTERNOON HIGHS AROUND 40-MID 40S (10-15 DEGREES BELOW NORMAL).
SHOWERS WILL CONTINUE INTO TUESDAY NIGHT...COVERAGE MAY DECREASE
WITH ON DOWNWARD SIDE OF DIURNAL HEATING CYCLE BUT THEY WILL STILL
BE AROUND.  COOLING TEMPERATURES ALSO WILL TREND PRECIPITATION TO
ALL SNOW SHOWERS TUESDAY EVENING.

WEDNESDAY...MORE OF THE SAME FOR WEDNESDAY WITH CONTINUED COOL
CYCLONIC FLOW AND VARIOUS DISTURBANCES ROTATING AROUND THE PARENT
VORTEX.  HIGH TEMPERATURES PROBABLY A FEW DEGREES COOLER WEDNESDAY
AFTERNOON...WITH MORE TEMPERATURES STUCK BELOW 40 DEGREES LIKELY.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

THE PERIOD PICKS UP JUST AS THE PREVIOUS LEFT OFF WITH UPPER LEVEL
TROUGHING OVERHEAD AND MULTIPLE WEAK WAVES ROTATING THROUGH THE BASE
OF THE TROUGH...BRINGING RAIN/SNOW SHOWER CHANCES WEDNESDAY NIGHT
AND INTO THE DAY THURSDAY. AS MENTIONED BY PRIOR SHIFT...THE
MOVEMENT OF THE OVERALL PATTERN LOOKS MINIMAL THROUGH THE WEEKEND
WITH TROUGHING CLOSE ENOUGH WHERE ANY SUBTLE WAVE COULD KICK OFF
ADDITIONAL SHOWER ACTIVITY. HAVE GONE AHEAD AND ADDED LOW END CHANCE
POPS FOR THURSDAY NIGHT (MAINLY DIRECTLY DOWNWIND OF LAKE MICHIGAN
AND FOR THE EASTERN U.P.)...BUT WILL KEEP A MAINLY DRY FORECAST FROM
FRIDAY THROUGH SUNDAY AS THE MAJORITY OF THE TIME LOOKS TO REMAIN
PRECIPITATION FREE.

NO DOUBT THE OVERALL PATTERN WILL BE A RATHER CHILLY ONE...WITH H8
TEMPS APPROACHING -8C THROUGHOUT THE PERIOD. A BLENDED MODEL
GUIDANCE APPROACH WOULD SUGGEST HIGH TEMPERATURES STUCK IN THE UPPER
30S AND 40S (A SOLID 10-15 DEGREES BELOW NORMAL) AND LOWS MAINLY IN
THE 20S TO LOWER 30S.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 737 PM EDT SUN APR 19 2015

CONDITIONS DETERIORATING TO IFR TONIGHT. SOME IMPROVEMENT MONDAY.

LOW PRESSURE IN W CENTRAL INDIANA WILL LIFT NORTH...CROSSING
NORTHERN LOWER MI MONDAY MORNING. RAIN SHIELD IS SLOWLY ADVANCING
NORTH INTO CENTRAL LOWER MI...WITH SOME SHRA DEVELOPING OUT AHEAD.
RAIN WILL STEADILY ADVANCE INTO THE REGION TONIGHT...RESULTING IN
LOWERING CIGS/VSBYS WITH TIMES. ALL SITES SHOULD SEE IFR CIGS FOR
A PERIOD LATE TONIGHT INTO MONDAY MORNING. IMPROVING TO MVFR
DURING THE DAY MONDAY...THOUGH WITH SOME -SHRA LINGERING.

GUSTY EAST WINDS WILL LIGHTEN UP OVERNIGHT...WITH SOMEWHAT
BLUSTERY WEST WINDS DEVELOPING BY MONDAY AFTERNOON.


&&

.MARINE...
ISSUED AT 402 PM EDT SUN APR 19 2015

TONIGHT THROUGH TUESDAY...EAST WINDS AHEAD OF THE SFC LOW WILL
CONTINUE TO INCREASE ACROSS THE UPPER GREAT LAKES AS THE PRESSURE
GRADIENT TIGHTENS UP ESPECIALLY OVER LAKE HURON AND E UPPER. THE SFC
LOW MOVES OVER N LAKE MICHIGAN AND IT LOOKS LIKE THE GRADIENT SHOULD
JUST BE SLACK ENOUGH FOR THE WINDS TO REMAIN BELOW MOST OF THE SMALL
CRAFT CRITERIA IN THE NEARSHORE WATERS. ONCE THE SFC LOW MOVES NORTH
OF THE UPPER MICHIGAN, THE PRESSURE GRADIENT WILL TIGHTEN BRIEFLY
OVER THE UPPER GREAT LAKES BRINGING SMALL CRAFT CRITERIA TO MOST, IF
NOT ALL OF THE NEARSHORES MONDAY AFTERNOON AND MONDAY NIGHT.
TUESDAY, AS THE SFC LOW STALLS NORTH OF LAKE SUPERIOR, THE WINDS
WILL INCREASE AS THE GRADIENT AGAIN TIGHTENS, AND THEN RELAXES BY
THE AFTERNOON.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LSZ321-322.

&&

$$

UPDATE...JAZ
NEAR TERM...JSL
SHORT TERM...JPB
LONG TERM...GILLEN
AVIATION...JAZ
MARINE...JSL



000
FXUS63 KAPX 200135
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
935 PM EDT SUN APR 19 2015

.UPDATE...
ISSUED AT 935 PM EDT SUN APR 19 2015

IT HAS BEEN IN NO HURRY...BUT WIDESPREAD RAIN IS MAKING STEADY
INROADS NORTHWARD ACROSS CENTRAL LOWER MI. LEADING EDGE IS NOW A
BIT NORTH OF GLADWIN/STANDISH. AHEAD OF THIS...A BAND OF -SHRA
HAS ADVANCED TO A FRANKFORT-GLR-PRESQUE ISLE LT LINE. HAVE BEEN
ADJUSTING TIMING OF PRECIP ONSET...MAINLY TO SLOW THINGS DOWN A
BIT. BUT THE MAIN GIST OF THE FORECAST...I.E. EVERYONE EVENTUALLY
GETS WET TONIGHT...IS FINE.

&&

.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 402 PM EDT SUN APR 19 2015

HIGH IMPACT WEATHER: MINIMAL

FORECAST CHALLENGE: TIMING OF THE RAIN TONIGHT.

OVERVIEW...WHILE THE MOISTURE HAS BEEN INCREASING ALONG THE LAKE
HURON SHORE AND INLAND OF NE LOWER, NW LOWER HAS BEEN DRYING OUT
WITH A GOOD PORTION OF THE AREA WEST OF I-75 HAVING FALLEN BELOW
25%. IN E UPPER, THE RH HAS BEEN BETWEEN 40% AND 45%. WHAT THIS IS
DOING IS DELAYING THE RAIN SHIELD`S TRAVEL NORTH, WHICH HAD JUST
MADE IT TO THE MICHIGAN/INDIANA BORDER AROUND 19Z. USING THE TIMING
TOOL ON AWIPS, IT LOOKS LIKE THE RAIN SHOULD GET TO THE M-55
CORRIDOR AROUND 23Z, M-72 AROUND 00Z, M-32 AROUND 01Z, AND THE
STRAIT BETWEEN 02Z AND 03Z.

DETAILS FOR TONIGHT...AS WAS MENTIONED, TRYING TO TIME THIS SYSTEM
WITH THE DRY AIR IN THE LOWER LEVELS IS MADDENING. THE QUESTION
ISN`T IF THE AIR WILL LEAVE, BUT WHEN AS THE SFC LOW WILL, AS IT
MOVES UP FROM THE MID-MISSISSIPPI VALLEY, OVERWHELM WITH DRY AIR
WITH ITS MOISTURE, AND ALLOW THE RAIN TO FALL ALL THE WAY TO THE
SFC. HOWEVER, ONCE THE RAIN STARTS, IT WILL FALL THROUGH THE NIGHT
AS THE SFC NORTH OVER THE WESTERN PART OF THE STATE BETWEEN 06Z AND
12Z. THIS SFC LOW AND ASSOCIATED 500 MB SHORTWAVE TROUGH AND 50 KNOT
SPEED MAX THAT MOVES OVER THE STATE, OVER THE WARM FRONT. WITH THE
PWAT AROUND 1.0" OVERNIGHT OVER THE FORECAST AREA, WILL EXPECT
THAT A DECENT STEADY RAIN WILL RESULT.

&&

.SHORT TERM...(MONDAY THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

...SHOWERY/COOL/UNSETTLED THROUGH MIDWEEK...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: WELL-DEFINED SPLIT FLOW PATTERN FROM THE
END OF LAST WEEK NOW CONSOLIDATING AS NORTHERN BRANCH SHORT WAVE
TROUGH DIGS SOUTHEAST FROM WESTERN CANADA AND SCOOPS UP PESKY
SOUTHERN BRANCH VORTEX THAT HAS BEEN SPINNING ACROSS THE GREAT
BASIN/SOUTHERN ROCKIES SINCE THE MIDDLE OF LAST WEEK.  POSITIVE
PACIFIC TELECONNECTIONS LEADING TO A MORE AMPLIFIED PATTERN (BIG
TROUGH EAST OF THE DATELINE WITH +PNA RIDGING ALONG THE WEST COAST
OF NORTH AMERICA.  THIS CONSOLIDATING CENTRAL NORTH AMERICAN TROUGH
WILL BECOME THE PREDOMINANT WEATHER FEATURE THIS WEEK AS IT TAKES UP
RESIDENCE WITH REX BLOCKING ALONG THE WEST COAST...WITH AN UPPER LOW
EVENTUALLY PARKING ITSELF OVER THE GREAT LAKES BY MIDWEEK.

SOUTHERN BRANCH DISTURBANCE LOOKS TO COME OUT IN TWO PIECES
MONDAY...WHILE CLOSED CIRCULATION ALOFT DEVELOPS OVER NORTHWEST
ONTARIO/UPPER MIDWEST.  UPPER LOW THEN SETTLES OVER LAKE SUPERIOR
TUESDAY AND HANGS IN THROUGH MIDWEEK.  AT THE SURFACE...LEAD
SOUTHERN BRANCH SHORT WAVE TROUGH HAS AN ASSOCIATED SURFACE LOW OVER
THE MID MISSISSIPPI VALLEY THAT IS FORECAST TO DEEPEN AND LIFT NORTH
INTO LOWER MICHIGAN BY MONDAY MORNING...PROBABLY BELOW 990MB WHICH
IS PRETTY SIGNIFICANT BY MID-APRIL STANDARDS.  THIS LOW WILL PULL
COOLER AIR INTO MICHIGAN STARTING MONDAY NIGHT...CYCLONIC FLOW
LINGERS INTO MIDWEEK.

PRIMARY FORECAST CONCERNS: VARYING PRECIPITATION CHANCES THROUGH
MIDWEEK...AS WELL AS PRECIPITATION TYPE.

MONDAY...12Z SOUNDINGS AND GOES SOUNDER IMAGERY SHOWS A NICE SURGE
OF MOISTURE COMING UP ACROSS THE SOUTHEASTERN STATES (1.00-1.50 INCH
PRECIPITABLE WATER) WHICH IS PUSHING A LARGE ARE OF RAIN NORTHWARD
ACROSS THE OHIO VALLEY...AND EVENTUALLY INTO MICHIGAN TONIGHT/MONDAY
MORNING.  THIS WILL PUSH THROUGH THE FORECAST AREA MONDAY MORNING
(PERHAPS FAIRLY QUICKLY) WITH MID LEVEL DRYING (POSSIBLY TAPERING
OFF TO A PERIOD OF DRIZZLE).  SURFACE LOW TRACKS ACROSS NORTHERN
LOWER MONDAY MORNING...BEHIND THAT A LINGERING BAND OF DEFORMATION/
FRONTOGENETIC PRECIPITATION WILL ROTATE IN FROM THE WEST DURING THE
AFTERNOON HOURS.  IN ADDITION...COULD SEE SOME CONVECTIVE PRECIP
CLOSE TO THE SOUTHEAST PORTION OF THE FORECAST AREA DURING THE LATE
MORNING/AFTERNOON WITH SOME ELEVATED INSTABILITY (TQ INDICES
POTENTIALLY IN THE 16-20C RANGE NEAR LOW LEVEL THETA-E RIDGE) AND
SECOND PIECE OF SOUTHERN BRANCH ENERGY SWINGING NORTHEAST ACROSS THE
LOWER PENINSULA.  MORE LIKELY THIS ACTIVITY WOULD OCCUR ACROSS THE
THUMB INTO LAKE HURON...BUT MAY BE CLOSE.  WILL NOT TRY AND VARY
PRECIP PROBABILITIES IN THE FORECAST GRIDS TO ACCOUNT FOR TIMING OF
VARIOUS WAVES OF PRECIPITATION (AS IT WILL BE WRONG ANYHOW)...WITH A
GENERIC HIGH LIKELY/CATEGORICAL POP THROUGH THE DAY SUFFICIENT FOR
NOW. AS LONG AS INITIAL AREA OF RAIN SCOOTS NORTH QUICKLY MONDAY
MORNING... NOT EXPECT A LOT OF RAINFALL IN THE 12Z-00Z TIME FRAME
(UNLESS CONVECTION CAN CLIP FAR EASTERN ZONES DURING THE AFTERNOON)
WITH FORECAST 12H QPF UNDER 0.25 INCH THOUGH COULD BE HIGHER ACROSS
EASTERN UPPER/FAR NORTHEAST LOWER GIVEN THE ABOVE CAVEATS.  TRACK OF
THE LOW RIGHT ACROSS LOWER MICHIGAN WILL LEAD TO SOME TRICKY
TEMPERATURE FORECASTS...IN GENERAL COOLER WEST AND WARMER EAST WITH
FALLING TEMPERATURES DURING THE MID/LATE AFTERNOON AS WINDS SWITCH
AROUND TO A MORE WESTERLY COMPONENT.

WHAT REMAINS OF DEFORMATION PRECIP BAND EXPECTED TO LIFT NORTHEAST
ACROSS NORTHERN MICHIGAN MONDAY EVENING...AFTER THAT MAY BE ON THE
QUIET SIDE OVERNIGHT AND WILL CONFINE POPS TO THE EVENING HOURS.
PRECIP TYPE MAY BE IN QUESTION ACROSS EASTERN UPPER AS DEPTH OF
SURFACE BASED WARM LAYER SHRINKS.  AS NORTHERN BRANCH SHORT WAVE
TROUGHS START GETTING INVOLVED IN THE FORECAST SCENARIO CAN`T RULE
OUT SOME ADDITIONAL SHOWERS DEVELOPING OVERNIGHT INTO TUESDAY
MORNING BUT NOT CONVINCED THE PROBABILITY RISES TO A SUFFICIENT
LEVEL TO INCLUDE IN THE FORECAST...WILL LEAVE IT OUT AND MAINTAIN
CONTINUITY.

TUESDAY...DEEP LAYER CYCLONIC FLOW ACROSS THE UPPER LAKES SPELLS
UNSETTLED AND NOT WARM WEATHER FOR TUESDAY.  DEEP MOISTURE WILL
ROTATE AROUND THE SOUTH SIDE OF THE UPPER LOW...AND COOL
TEMPERATURES ALOFT (AT OR BELOW -30C/500MB) WILL ADD A DIURNAL
COMPONENT TO SUPPORT SHOWERS...AND GIVEN COOL TEMPERATURES PRECIP
COULD FALL AS RAIN/SNOW/GRAUPEL.  GUSTY SOUTHWEST WINDS (20-30MPH
GUSTS PROBABLE NORTHERN LOWER) WON`T MAKE IT FEEL ANY WARMER...WITH
AFTERNOON HIGHS AROUND 40-MID 40S (10-15 DEGREES BELOW NORMAL).
SHOWERS WILL CONTINUE INTO TUESDAY NIGHT...COVERAGE MAY DECREASE
WITH ON DOWNWARD SIDE OF DIURNAL HEATING CYCLE BUT THEY WILL STILL
BE AROUND.  COOLING TEMPERATURES ALSO WILL TREND PRECIPITATION TO
ALL SNOW SHOWERS TUESDAY EVENING.

WEDNESDAY...MORE OF THE SAME FOR WEDNESDAY WITH CONTINUED COOL
CYCLONIC FLOW AND VARIOUS DISTURBANCES ROTATING AROUND THE PARENT
VORTEX.  HIGH TEMPERATURES PROBABLY A FEW DEGREES COOLER WEDNESDAY
AFTERNOON...WITH MORE TEMPERATURES STUCK BELOW 40 DEGREES LIKELY.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

THE PERIOD PICKS UP JUST AS THE PREVIOUS LEFT OFF WITH UPPER LEVEL
TROUGHING OVERHEAD AND MULTIPLE WEAK WAVES ROTATING THROUGH THE BASE
OF THE TROUGH...BRINGING RAIN/SNOW SHOWER CHANCES WEDNESDAY NIGHT
AND INTO THE DAY THURSDAY. AS MENTIONED BY PRIOR SHIFT...THE
MOVEMENT OF THE OVERALL PATTERN LOOKS MINIMAL THROUGH THE WEEKEND
WITH TROUGHING CLOSE ENOUGH WHERE ANY SUBTLE WAVE COULD KICK OFF
ADDITIONAL SHOWER ACTIVITY. HAVE GONE AHEAD AND ADDED LOW END CHANCE
POPS FOR THURSDAY NIGHT (MAINLY DIRECTLY DOWNWIND OF LAKE MICHIGAN
AND FOR THE EASTERN U.P.)...BUT WILL KEEP A MAINLY DRY FORECAST FROM
FRIDAY THROUGH SUNDAY AS THE MAJORITY OF THE TIME LOOKS TO REMAIN
PRECIPITATION FREE.

NO DOUBT THE OVERALL PATTERN WILL BE A RATHER CHILLY ONE...WITH H8
TEMPS APPROACHING -8C THROUGHOUT THE PERIOD. A BLENDED MODEL
GUIDANCE APPROACH WOULD SUGGEST HIGH TEMPERATURES STUCK IN THE UPPER
30S AND 40S (A SOLID 10-15 DEGREES BELOW NORMAL) AND LOWS MAINLY IN
THE 20S TO LOWER 30S.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 737 PM EDT SUN APR 19 2015

CONDITIONS DETERIORATING TO IFR TONIGHT. SOME IMPROVEMENT MONDAY.

LOW PRESSURE IN W CENTRAL INDIANA WILL LIFT NORTH...CROSSING
NORTHERN LOWER MI MONDAY MORNING. RAIN SHIELD IS SLOWLY ADVANCING
NORTH INTO CENTRAL LOWER MI...WITH SOME SHRA DEVELOPING OUT AHEAD.
RAIN WILL STEADILY ADVANCE INTO THE REGION TONIGHT...RESULTING IN
LOWERING CIGS/VSBYS WITH TIMES. ALL SITES SHOULD SEE IFR CIGS FOR
A PERIOD LATE TONIGHT INTO MONDAY MORNING. IMPROVING TO MVFR
DURING THE DAY MONDAY...THOUGH WITH SOME -SHRA LINGERING.

GUSTY EAST WINDS WILL LIGHTEN UP OVERNIGHT...WITH SOMEWHAT
BLUSTERY WEST WINDS DEVELOPING BY MONDAY AFTERNOON.


&&

.MARINE...
ISSUED AT 402 PM EDT SUN APR 19 2015

TONIGHT THROUGH TUESDAY...EAST WINDS AHEAD OF THE SFC LOW WILL
CONTINUE TO INCREASE ACROSS THE UPPER GREAT LAKES AS THE PRESSURE
GRADIENT TIGHTENS UP ESPECIALLY OVER LAKE HURON AND E UPPER. THE SFC
LOW MOVES OVER N LAKE MICHIGAN AND IT LOOKS LIKE THE GRADIENT SHOULD
JUST BE SLACK ENOUGH FOR THE WINDS TO REMAIN BELOW MOST OF THE SMALL
CRAFT CRITERIA IN THE NEARSHORE WATERS. ONCE THE SFC LOW MOVES NORTH
OF THE UPPER MICHIGAN, THE PRESSURE GRADIENT WILL TIGHTEN BRIEFLY
OVER THE UPPER GREAT LAKES BRINGING SMALL CRAFT CRITERIA TO MOST, IF
NOT ALL OF THE NEARSHORES MONDAY AFTERNOON AND MONDAY NIGHT.
TUESDAY, AS THE SFC LOW STALLS NORTH OF LAKE SUPERIOR, THE WINDS
WILL INCREASE AS THE GRADIENT AGAIN TIGHTENS, AND THEN RELAXES BY
THE AFTERNOON.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LSZ321-322.

&&

$$

UPDATE...JAZ
NEAR TERM...JSL
SHORT TERM...JPB
LONG TERM...GILLEN
AVIATION...JAZ
MARINE...JSL



000
FXUS63 KAPX 200135
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
935 PM EDT SUN APR 19 2015

.UPDATE...
ISSUED AT 935 PM EDT SUN APR 19 2015

IT HAS BEEN IN NO HURRY...BUT WIDESPREAD RAIN IS MAKING STEADY
INROADS NORTHWARD ACROSS CENTRAL LOWER MI. LEADING EDGE IS NOW A
BIT NORTH OF GLADWIN/STANDISH. AHEAD OF THIS...A BAND OF -SHRA
HAS ADVANCED TO A FRANKFORT-GLR-PRESQUE ISLE LT LINE. HAVE BEEN
ADJUSTING TIMING OF PRECIP ONSET...MAINLY TO SLOW THINGS DOWN A
BIT. BUT THE MAIN GIST OF THE FORECAST...I.E. EVERYONE EVENTUALLY
GETS WET TONIGHT...IS FINE.

&&

.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 402 PM EDT SUN APR 19 2015

HIGH IMPACT WEATHER: MINIMAL

FORECAST CHALLENGE: TIMING OF THE RAIN TONIGHT.

OVERVIEW...WHILE THE MOISTURE HAS BEEN INCREASING ALONG THE LAKE
HURON SHORE AND INLAND OF NE LOWER, NW LOWER HAS BEEN DRYING OUT
WITH A GOOD PORTION OF THE AREA WEST OF I-75 HAVING FALLEN BELOW
25%. IN E UPPER, THE RH HAS BEEN BETWEEN 40% AND 45%. WHAT THIS IS
DOING IS DELAYING THE RAIN SHIELD`S TRAVEL NORTH, WHICH HAD JUST
MADE IT TO THE MICHIGAN/INDIANA BORDER AROUND 19Z. USING THE TIMING
TOOL ON AWIPS, IT LOOKS LIKE THE RAIN SHOULD GET TO THE M-55
CORRIDOR AROUND 23Z, M-72 AROUND 00Z, M-32 AROUND 01Z, AND THE
STRAIT BETWEEN 02Z AND 03Z.

DETAILS FOR TONIGHT...AS WAS MENTIONED, TRYING TO TIME THIS SYSTEM
WITH THE DRY AIR IN THE LOWER LEVELS IS MADDENING. THE QUESTION
ISN`T IF THE AIR WILL LEAVE, BUT WHEN AS THE SFC LOW WILL, AS IT
MOVES UP FROM THE MID-MISSISSIPPI VALLEY, OVERWHELM WITH DRY AIR
WITH ITS MOISTURE, AND ALLOW THE RAIN TO FALL ALL THE WAY TO THE
SFC. HOWEVER, ONCE THE RAIN STARTS, IT WILL FALL THROUGH THE NIGHT
AS THE SFC NORTH OVER THE WESTERN PART OF THE STATE BETWEEN 06Z AND
12Z. THIS SFC LOW AND ASSOCIATED 500 MB SHORTWAVE TROUGH AND 50 KNOT
SPEED MAX THAT MOVES OVER THE STATE, OVER THE WARM FRONT. WITH THE
PWAT AROUND 1.0" OVERNIGHT OVER THE FORECAST AREA, WILL EXPECT
THAT A DECENT STEADY RAIN WILL RESULT.

&&

.SHORT TERM...(MONDAY THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

...SHOWERY/COOL/UNSETTLED THROUGH MIDWEEK...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: WELL-DEFINED SPLIT FLOW PATTERN FROM THE
END OF LAST WEEK NOW CONSOLIDATING AS NORTHERN BRANCH SHORT WAVE
TROUGH DIGS SOUTHEAST FROM WESTERN CANADA AND SCOOPS UP PESKY
SOUTHERN BRANCH VORTEX THAT HAS BEEN SPINNING ACROSS THE GREAT
BASIN/SOUTHERN ROCKIES SINCE THE MIDDLE OF LAST WEEK.  POSITIVE
PACIFIC TELECONNECTIONS LEADING TO A MORE AMPLIFIED PATTERN (BIG
TROUGH EAST OF THE DATELINE WITH +PNA RIDGING ALONG THE WEST COAST
OF NORTH AMERICA.  THIS CONSOLIDATING CENTRAL NORTH AMERICAN TROUGH
WILL BECOME THE PREDOMINANT WEATHER FEATURE THIS WEEK AS IT TAKES UP
RESIDENCE WITH REX BLOCKING ALONG THE WEST COAST...WITH AN UPPER LOW
EVENTUALLY PARKING ITSELF OVER THE GREAT LAKES BY MIDWEEK.

SOUTHERN BRANCH DISTURBANCE LOOKS TO COME OUT IN TWO PIECES
MONDAY...WHILE CLOSED CIRCULATION ALOFT DEVELOPS OVER NORTHWEST
ONTARIO/UPPER MIDWEST.  UPPER LOW THEN SETTLES OVER LAKE SUPERIOR
TUESDAY AND HANGS IN THROUGH MIDWEEK.  AT THE SURFACE...LEAD
SOUTHERN BRANCH SHORT WAVE TROUGH HAS AN ASSOCIATED SURFACE LOW OVER
THE MID MISSISSIPPI VALLEY THAT IS FORECAST TO DEEPEN AND LIFT NORTH
INTO LOWER MICHIGAN BY MONDAY MORNING...PROBABLY BELOW 990MB WHICH
IS PRETTY SIGNIFICANT BY MID-APRIL STANDARDS.  THIS LOW WILL PULL
COOLER AIR INTO MICHIGAN STARTING MONDAY NIGHT...CYCLONIC FLOW
LINGERS INTO MIDWEEK.

PRIMARY FORECAST CONCERNS: VARYING PRECIPITATION CHANCES THROUGH
MIDWEEK...AS WELL AS PRECIPITATION TYPE.

MONDAY...12Z SOUNDINGS AND GOES SOUNDER IMAGERY SHOWS A NICE SURGE
OF MOISTURE COMING UP ACROSS THE SOUTHEASTERN STATES (1.00-1.50 INCH
PRECIPITABLE WATER) WHICH IS PUSHING A LARGE ARE OF RAIN NORTHWARD
ACROSS THE OHIO VALLEY...AND EVENTUALLY INTO MICHIGAN TONIGHT/MONDAY
MORNING.  THIS WILL PUSH THROUGH THE FORECAST AREA MONDAY MORNING
(PERHAPS FAIRLY QUICKLY) WITH MID LEVEL DRYING (POSSIBLY TAPERING
OFF TO A PERIOD OF DRIZZLE).  SURFACE LOW TRACKS ACROSS NORTHERN
LOWER MONDAY MORNING...BEHIND THAT A LINGERING BAND OF DEFORMATION/
FRONTOGENETIC PRECIPITATION WILL ROTATE IN FROM THE WEST DURING THE
AFTERNOON HOURS.  IN ADDITION...COULD SEE SOME CONVECTIVE PRECIP
CLOSE TO THE SOUTHEAST PORTION OF THE FORECAST AREA DURING THE LATE
MORNING/AFTERNOON WITH SOME ELEVATED INSTABILITY (TQ INDICES
POTENTIALLY IN THE 16-20C RANGE NEAR LOW LEVEL THETA-E RIDGE) AND
SECOND PIECE OF SOUTHERN BRANCH ENERGY SWINGING NORTHEAST ACROSS THE
LOWER PENINSULA.  MORE LIKELY THIS ACTIVITY WOULD OCCUR ACROSS THE
THUMB INTO LAKE HURON...BUT MAY BE CLOSE.  WILL NOT TRY AND VARY
PRECIP PROBABILITIES IN THE FORECAST GRIDS TO ACCOUNT FOR TIMING OF
VARIOUS WAVES OF PRECIPITATION (AS IT WILL BE WRONG ANYHOW)...WITH A
GENERIC HIGH LIKELY/CATEGORICAL POP THROUGH THE DAY SUFFICIENT FOR
NOW. AS LONG AS INITIAL AREA OF RAIN SCOOTS NORTH QUICKLY MONDAY
MORNING... NOT EXPECT A LOT OF RAINFALL IN THE 12Z-00Z TIME FRAME
(UNLESS CONVECTION CAN CLIP FAR EASTERN ZONES DURING THE AFTERNOON)
WITH FORECAST 12H QPF UNDER 0.25 INCH THOUGH COULD BE HIGHER ACROSS
EASTERN UPPER/FAR NORTHEAST LOWER GIVEN THE ABOVE CAVEATS.  TRACK OF
THE LOW RIGHT ACROSS LOWER MICHIGAN WILL LEAD TO SOME TRICKY
TEMPERATURE FORECASTS...IN GENERAL COOLER WEST AND WARMER EAST WITH
FALLING TEMPERATURES DURING THE MID/LATE AFTERNOON AS WINDS SWITCH
AROUND TO A MORE WESTERLY COMPONENT.

WHAT REMAINS OF DEFORMATION PRECIP BAND EXPECTED TO LIFT NORTHEAST
ACROSS NORTHERN MICHIGAN MONDAY EVENING...AFTER THAT MAY BE ON THE
QUIET SIDE OVERNIGHT AND WILL CONFINE POPS TO THE EVENING HOURS.
PRECIP TYPE MAY BE IN QUESTION ACROSS EASTERN UPPER AS DEPTH OF
SURFACE BASED WARM LAYER SHRINKS.  AS NORTHERN BRANCH SHORT WAVE
TROUGHS START GETTING INVOLVED IN THE FORECAST SCENARIO CAN`T RULE
OUT SOME ADDITIONAL SHOWERS DEVELOPING OVERNIGHT INTO TUESDAY
MORNING BUT NOT CONVINCED THE PROBABILITY RISES TO A SUFFICIENT
LEVEL TO INCLUDE IN THE FORECAST...WILL LEAVE IT OUT AND MAINTAIN
CONTINUITY.

TUESDAY...DEEP LAYER CYCLONIC FLOW ACROSS THE UPPER LAKES SPELLS
UNSETTLED AND NOT WARM WEATHER FOR TUESDAY.  DEEP MOISTURE WILL
ROTATE AROUND THE SOUTH SIDE OF THE UPPER LOW...AND COOL
TEMPERATURES ALOFT (AT OR BELOW -30C/500MB) WILL ADD A DIURNAL
COMPONENT TO SUPPORT SHOWERS...AND GIVEN COOL TEMPERATURES PRECIP
COULD FALL AS RAIN/SNOW/GRAUPEL.  GUSTY SOUTHWEST WINDS (20-30MPH
GUSTS PROBABLE NORTHERN LOWER) WON`T MAKE IT FEEL ANY WARMER...WITH
AFTERNOON HIGHS AROUND 40-MID 40S (10-15 DEGREES BELOW NORMAL).
SHOWERS WILL CONTINUE INTO TUESDAY NIGHT...COVERAGE MAY DECREASE
WITH ON DOWNWARD SIDE OF DIURNAL HEATING CYCLE BUT THEY WILL STILL
BE AROUND.  COOLING TEMPERATURES ALSO WILL TREND PRECIPITATION TO
ALL SNOW SHOWERS TUESDAY EVENING.

WEDNESDAY...MORE OF THE SAME FOR WEDNESDAY WITH CONTINUED COOL
CYCLONIC FLOW AND VARIOUS DISTURBANCES ROTATING AROUND THE PARENT
VORTEX.  HIGH TEMPERATURES PROBABLY A FEW DEGREES COOLER WEDNESDAY
AFTERNOON...WITH MORE TEMPERATURES STUCK BELOW 40 DEGREES LIKELY.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

THE PERIOD PICKS UP JUST AS THE PREVIOUS LEFT OFF WITH UPPER LEVEL
TROUGHING OVERHEAD AND MULTIPLE WEAK WAVES ROTATING THROUGH THE BASE
OF THE TROUGH...BRINGING RAIN/SNOW SHOWER CHANCES WEDNESDAY NIGHT
AND INTO THE DAY THURSDAY. AS MENTIONED BY PRIOR SHIFT...THE
MOVEMENT OF THE OVERALL PATTERN LOOKS MINIMAL THROUGH THE WEEKEND
WITH TROUGHING CLOSE ENOUGH WHERE ANY SUBTLE WAVE COULD KICK OFF
ADDITIONAL SHOWER ACTIVITY. HAVE GONE AHEAD AND ADDED LOW END CHANCE
POPS FOR THURSDAY NIGHT (MAINLY DIRECTLY DOWNWIND OF LAKE MICHIGAN
AND FOR THE EASTERN U.P.)...BUT WILL KEEP A MAINLY DRY FORECAST FROM
FRIDAY THROUGH SUNDAY AS THE MAJORITY OF THE TIME LOOKS TO REMAIN
PRECIPITATION FREE.

NO DOUBT THE OVERALL PATTERN WILL BE A RATHER CHILLY ONE...WITH H8
TEMPS APPROACHING -8C THROUGHOUT THE PERIOD. A BLENDED MODEL
GUIDANCE APPROACH WOULD SUGGEST HIGH TEMPERATURES STUCK IN THE UPPER
30S AND 40S (A SOLID 10-15 DEGREES BELOW NORMAL) AND LOWS MAINLY IN
THE 20S TO LOWER 30S.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 737 PM EDT SUN APR 19 2015

CONDITIONS DETERIORATING TO IFR TONIGHT. SOME IMPROVEMENT MONDAY.

LOW PRESSURE IN W CENTRAL INDIANA WILL LIFT NORTH...CROSSING
NORTHERN LOWER MI MONDAY MORNING. RAIN SHIELD IS SLOWLY ADVANCING
NORTH INTO CENTRAL LOWER MI...WITH SOME SHRA DEVELOPING OUT AHEAD.
RAIN WILL STEADILY ADVANCE INTO THE REGION TONIGHT...RESULTING IN
LOWERING CIGS/VSBYS WITH TIMES. ALL SITES SHOULD SEE IFR CIGS FOR
A PERIOD LATE TONIGHT INTO MONDAY MORNING. IMPROVING TO MVFR
DURING THE DAY MONDAY...THOUGH WITH SOME -SHRA LINGERING.

GUSTY EAST WINDS WILL LIGHTEN UP OVERNIGHT...WITH SOMEWHAT
BLUSTERY WEST WINDS DEVELOPING BY MONDAY AFTERNOON.


&&

.MARINE...
ISSUED AT 402 PM EDT SUN APR 19 2015

TONIGHT THROUGH TUESDAY...EAST WINDS AHEAD OF THE SFC LOW WILL
CONTINUE TO INCREASE ACROSS THE UPPER GREAT LAKES AS THE PRESSURE
GRADIENT TIGHTENS UP ESPECIALLY OVER LAKE HURON AND E UPPER. THE SFC
LOW MOVES OVER N LAKE MICHIGAN AND IT LOOKS LIKE THE GRADIENT SHOULD
JUST BE SLACK ENOUGH FOR THE WINDS TO REMAIN BELOW MOST OF THE SMALL
CRAFT CRITERIA IN THE NEARSHORE WATERS. ONCE THE SFC LOW MOVES NORTH
OF THE UPPER MICHIGAN, THE PRESSURE GRADIENT WILL TIGHTEN BRIEFLY
OVER THE UPPER GREAT LAKES BRINGING SMALL CRAFT CRITERIA TO MOST, IF
NOT ALL OF THE NEARSHORES MONDAY AFTERNOON AND MONDAY NIGHT.
TUESDAY, AS THE SFC LOW STALLS NORTH OF LAKE SUPERIOR, THE WINDS
WILL INCREASE AS THE GRADIENT AGAIN TIGHTENS, AND THEN RELAXES BY
THE AFTERNOON.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LSZ321-322.

&&

$$

UPDATE...JAZ
NEAR TERM...JSL
SHORT TERM...JPB
LONG TERM...GILLEN
AVIATION...JAZ
MARINE...JSL



000
FXUS63 KAPX 200135
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
935 PM EDT SUN APR 19 2015

.UPDATE...
ISSUED AT 935 PM EDT SUN APR 19 2015

IT HAS BEEN IN NO HURRY...BUT WIDESPREAD RAIN IS MAKING STEADY
INROADS NORTHWARD ACROSS CENTRAL LOWER MI. LEADING EDGE IS NOW A
BIT NORTH OF GLADWIN/STANDISH. AHEAD OF THIS...A BAND OF -SHRA
HAS ADVANCED TO A FRANKFORT-GLR-PRESQUE ISLE LT LINE. HAVE BEEN
ADJUSTING TIMING OF PRECIP ONSET...MAINLY TO SLOW THINGS DOWN A
BIT. BUT THE MAIN GIST OF THE FORECAST...I.E. EVERYONE EVENTUALLY
GETS WET TONIGHT...IS FINE.

&&

.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 402 PM EDT SUN APR 19 2015

HIGH IMPACT WEATHER: MINIMAL

FORECAST CHALLENGE: TIMING OF THE RAIN TONIGHT.

OVERVIEW...WHILE THE MOISTURE HAS BEEN INCREASING ALONG THE LAKE
HURON SHORE AND INLAND OF NE LOWER, NW LOWER HAS BEEN DRYING OUT
WITH A GOOD PORTION OF THE AREA WEST OF I-75 HAVING FALLEN BELOW
25%. IN E UPPER, THE RH HAS BEEN BETWEEN 40% AND 45%. WHAT THIS IS
DOING IS DELAYING THE RAIN SHIELD`S TRAVEL NORTH, WHICH HAD JUST
MADE IT TO THE MICHIGAN/INDIANA BORDER AROUND 19Z. USING THE TIMING
TOOL ON AWIPS, IT LOOKS LIKE THE RAIN SHOULD GET TO THE M-55
CORRIDOR AROUND 23Z, M-72 AROUND 00Z, M-32 AROUND 01Z, AND THE
STRAIT BETWEEN 02Z AND 03Z.

DETAILS FOR TONIGHT...AS WAS MENTIONED, TRYING TO TIME THIS SYSTEM
WITH THE DRY AIR IN THE LOWER LEVELS IS MADDENING. THE QUESTION
ISN`T IF THE AIR WILL LEAVE, BUT WHEN AS THE SFC LOW WILL, AS IT
MOVES UP FROM THE MID-MISSISSIPPI VALLEY, OVERWHELM WITH DRY AIR
WITH ITS MOISTURE, AND ALLOW THE RAIN TO FALL ALL THE WAY TO THE
SFC. HOWEVER, ONCE THE RAIN STARTS, IT WILL FALL THROUGH THE NIGHT
AS THE SFC NORTH OVER THE WESTERN PART OF THE STATE BETWEEN 06Z AND
12Z. THIS SFC LOW AND ASSOCIATED 500 MB SHORTWAVE TROUGH AND 50 KNOT
SPEED MAX THAT MOVES OVER THE STATE, OVER THE WARM FRONT. WITH THE
PWAT AROUND 1.0" OVERNIGHT OVER THE FORECAST AREA, WILL EXPECT
THAT A DECENT STEADY RAIN WILL RESULT.

&&

.SHORT TERM...(MONDAY THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

...SHOWERY/COOL/UNSETTLED THROUGH MIDWEEK...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: WELL-DEFINED SPLIT FLOW PATTERN FROM THE
END OF LAST WEEK NOW CONSOLIDATING AS NORTHERN BRANCH SHORT WAVE
TROUGH DIGS SOUTHEAST FROM WESTERN CANADA AND SCOOPS UP PESKY
SOUTHERN BRANCH VORTEX THAT HAS BEEN SPINNING ACROSS THE GREAT
BASIN/SOUTHERN ROCKIES SINCE THE MIDDLE OF LAST WEEK.  POSITIVE
PACIFIC TELECONNECTIONS LEADING TO A MORE AMPLIFIED PATTERN (BIG
TROUGH EAST OF THE DATELINE WITH +PNA RIDGING ALONG THE WEST COAST
OF NORTH AMERICA.  THIS CONSOLIDATING CENTRAL NORTH AMERICAN TROUGH
WILL BECOME THE PREDOMINANT WEATHER FEATURE THIS WEEK AS IT TAKES UP
RESIDENCE WITH REX BLOCKING ALONG THE WEST COAST...WITH AN UPPER LOW
EVENTUALLY PARKING ITSELF OVER THE GREAT LAKES BY MIDWEEK.

SOUTHERN BRANCH DISTURBANCE LOOKS TO COME OUT IN TWO PIECES
MONDAY...WHILE CLOSED CIRCULATION ALOFT DEVELOPS OVER NORTHWEST
ONTARIO/UPPER MIDWEST.  UPPER LOW THEN SETTLES OVER LAKE SUPERIOR
TUESDAY AND HANGS IN THROUGH MIDWEEK.  AT THE SURFACE...LEAD
SOUTHERN BRANCH SHORT WAVE TROUGH HAS AN ASSOCIATED SURFACE LOW OVER
THE MID MISSISSIPPI VALLEY THAT IS FORECAST TO DEEPEN AND LIFT NORTH
INTO LOWER MICHIGAN BY MONDAY MORNING...PROBABLY BELOW 990MB WHICH
IS PRETTY SIGNIFICANT BY MID-APRIL STANDARDS.  THIS LOW WILL PULL
COOLER AIR INTO MICHIGAN STARTING MONDAY NIGHT...CYCLONIC FLOW
LINGERS INTO MIDWEEK.

PRIMARY FORECAST CONCERNS: VARYING PRECIPITATION CHANCES THROUGH
MIDWEEK...AS WELL AS PRECIPITATION TYPE.

MONDAY...12Z SOUNDINGS AND GOES SOUNDER IMAGERY SHOWS A NICE SURGE
OF MOISTURE COMING UP ACROSS THE SOUTHEASTERN STATES (1.00-1.50 INCH
PRECIPITABLE WATER) WHICH IS PUSHING A LARGE ARE OF RAIN NORTHWARD
ACROSS THE OHIO VALLEY...AND EVENTUALLY INTO MICHIGAN TONIGHT/MONDAY
MORNING.  THIS WILL PUSH THROUGH THE FORECAST AREA MONDAY MORNING
(PERHAPS FAIRLY QUICKLY) WITH MID LEVEL DRYING (POSSIBLY TAPERING
OFF TO A PERIOD OF DRIZZLE).  SURFACE LOW TRACKS ACROSS NORTHERN
LOWER MONDAY MORNING...BEHIND THAT A LINGERING BAND OF DEFORMATION/
FRONTOGENETIC PRECIPITATION WILL ROTATE IN FROM THE WEST DURING THE
AFTERNOON HOURS.  IN ADDITION...COULD SEE SOME CONVECTIVE PRECIP
CLOSE TO THE SOUTHEAST PORTION OF THE FORECAST AREA DURING THE LATE
MORNING/AFTERNOON WITH SOME ELEVATED INSTABILITY (TQ INDICES
POTENTIALLY IN THE 16-20C RANGE NEAR LOW LEVEL THETA-E RIDGE) AND
SECOND PIECE OF SOUTHERN BRANCH ENERGY SWINGING NORTHEAST ACROSS THE
LOWER PENINSULA.  MORE LIKELY THIS ACTIVITY WOULD OCCUR ACROSS THE
THUMB INTO LAKE HURON...BUT MAY BE CLOSE.  WILL NOT TRY AND VARY
PRECIP PROBABILITIES IN THE FORECAST GRIDS TO ACCOUNT FOR TIMING OF
VARIOUS WAVES OF PRECIPITATION (AS IT WILL BE WRONG ANYHOW)...WITH A
GENERIC HIGH LIKELY/CATEGORICAL POP THROUGH THE DAY SUFFICIENT FOR
NOW. AS LONG AS INITIAL AREA OF RAIN SCOOTS NORTH QUICKLY MONDAY
MORNING... NOT EXPECT A LOT OF RAINFALL IN THE 12Z-00Z TIME FRAME
(UNLESS CONVECTION CAN CLIP FAR EASTERN ZONES DURING THE AFTERNOON)
WITH FORECAST 12H QPF UNDER 0.25 INCH THOUGH COULD BE HIGHER ACROSS
EASTERN UPPER/FAR NORTHEAST LOWER GIVEN THE ABOVE CAVEATS.  TRACK OF
THE LOW RIGHT ACROSS LOWER MICHIGAN WILL LEAD TO SOME TRICKY
TEMPERATURE FORECASTS...IN GENERAL COOLER WEST AND WARMER EAST WITH
FALLING TEMPERATURES DURING THE MID/LATE AFTERNOON AS WINDS SWITCH
AROUND TO A MORE WESTERLY COMPONENT.

WHAT REMAINS OF DEFORMATION PRECIP BAND EXPECTED TO LIFT NORTHEAST
ACROSS NORTHERN MICHIGAN MONDAY EVENING...AFTER THAT MAY BE ON THE
QUIET SIDE OVERNIGHT AND WILL CONFINE POPS TO THE EVENING HOURS.
PRECIP TYPE MAY BE IN QUESTION ACROSS EASTERN UPPER AS DEPTH OF
SURFACE BASED WARM LAYER SHRINKS.  AS NORTHERN BRANCH SHORT WAVE
TROUGHS START GETTING INVOLVED IN THE FORECAST SCENARIO CAN`T RULE
OUT SOME ADDITIONAL SHOWERS DEVELOPING OVERNIGHT INTO TUESDAY
MORNING BUT NOT CONVINCED THE PROBABILITY RISES TO A SUFFICIENT
LEVEL TO INCLUDE IN THE FORECAST...WILL LEAVE IT OUT AND MAINTAIN
CONTINUITY.

TUESDAY...DEEP LAYER CYCLONIC FLOW ACROSS THE UPPER LAKES SPELLS
UNSETTLED AND NOT WARM WEATHER FOR TUESDAY.  DEEP MOISTURE WILL
ROTATE AROUND THE SOUTH SIDE OF THE UPPER LOW...AND COOL
TEMPERATURES ALOFT (AT OR BELOW -30C/500MB) WILL ADD A DIURNAL
COMPONENT TO SUPPORT SHOWERS...AND GIVEN COOL TEMPERATURES PRECIP
COULD FALL AS RAIN/SNOW/GRAUPEL.  GUSTY SOUTHWEST WINDS (20-30MPH
GUSTS PROBABLE NORTHERN LOWER) WON`T MAKE IT FEEL ANY WARMER...WITH
AFTERNOON HIGHS AROUND 40-MID 40S (10-15 DEGREES BELOW NORMAL).
SHOWERS WILL CONTINUE INTO TUESDAY NIGHT...COVERAGE MAY DECREASE
WITH ON DOWNWARD SIDE OF DIURNAL HEATING CYCLE BUT THEY WILL STILL
BE AROUND.  COOLING TEMPERATURES ALSO WILL TREND PRECIPITATION TO
ALL SNOW SHOWERS TUESDAY EVENING.

WEDNESDAY...MORE OF THE SAME FOR WEDNESDAY WITH CONTINUED COOL
CYCLONIC FLOW AND VARIOUS DISTURBANCES ROTATING AROUND THE PARENT
VORTEX.  HIGH TEMPERATURES PROBABLY A FEW DEGREES COOLER WEDNESDAY
AFTERNOON...WITH MORE TEMPERATURES STUCK BELOW 40 DEGREES LIKELY.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

THE PERIOD PICKS UP JUST AS THE PREVIOUS LEFT OFF WITH UPPER LEVEL
TROUGHING OVERHEAD AND MULTIPLE WEAK WAVES ROTATING THROUGH THE BASE
OF THE TROUGH...BRINGING RAIN/SNOW SHOWER CHANCES WEDNESDAY NIGHT
AND INTO THE DAY THURSDAY. AS MENTIONED BY PRIOR SHIFT...THE
MOVEMENT OF THE OVERALL PATTERN LOOKS MINIMAL THROUGH THE WEEKEND
WITH TROUGHING CLOSE ENOUGH WHERE ANY SUBTLE WAVE COULD KICK OFF
ADDITIONAL SHOWER ACTIVITY. HAVE GONE AHEAD AND ADDED LOW END CHANCE
POPS FOR THURSDAY NIGHT (MAINLY DIRECTLY DOWNWIND OF LAKE MICHIGAN
AND FOR THE EASTERN U.P.)...BUT WILL KEEP A MAINLY DRY FORECAST FROM
FRIDAY THROUGH SUNDAY AS THE MAJORITY OF THE TIME LOOKS TO REMAIN
PRECIPITATION FREE.

NO DOUBT THE OVERALL PATTERN WILL BE A RATHER CHILLY ONE...WITH H8
TEMPS APPROACHING -8C THROUGHOUT THE PERIOD. A BLENDED MODEL
GUIDANCE APPROACH WOULD SUGGEST HIGH TEMPERATURES STUCK IN THE UPPER
30S AND 40S (A SOLID 10-15 DEGREES BELOW NORMAL) AND LOWS MAINLY IN
THE 20S TO LOWER 30S.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 737 PM EDT SUN APR 19 2015

CONDITIONS DETERIORATING TO IFR TONIGHT. SOME IMPROVEMENT MONDAY.

LOW PRESSURE IN W CENTRAL INDIANA WILL LIFT NORTH...CROSSING
NORTHERN LOWER MI MONDAY MORNING. RAIN SHIELD IS SLOWLY ADVANCING
NORTH INTO CENTRAL LOWER MI...WITH SOME SHRA DEVELOPING OUT AHEAD.
RAIN WILL STEADILY ADVANCE INTO THE REGION TONIGHT...RESULTING IN
LOWERING CIGS/VSBYS WITH TIMES. ALL SITES SHOULD SEE IFR CIGS FOR
A PERIOD LATE TONIGHT INTO MONDAY MORNING. IMPROVING TO MVFR
DURING THE DAY MONDAY...THOUGH WITH SOME -SHRA LINGERING.

GUSTY EAST WINDS WILL LIGHTEN UP OVERNIGHT...WITH SOMEWHAT
BLUSTERY WEST WINDS DEVELOPING BY MONDAY AFTERNOON.


&&

.MARINE...
ISSUED AT 402 PM EDT SUN APR 19 2015

TONIGHT THROUGH TUESDAY...EAST WINDS AHEAD OF THE SFC LOW WILL
CONTINUE TO INCREASE ACROSS THE UPPER GREAT LAKES AS THE PRESSURE
GRADIENT TIGHTENS UP ESPECIALLY OVER LAKE HURON AND E UPPER. THE SFC
LOW MOVES OVER N LAKE MICHIGAN AND IT LOOKS LIKE THE GRADIENT SHOULD
JUST BE SLACK ENOUGH FOR THE WINDS TO REMAIN BELOW MOST OF THE SMALL
CRAFT CRITERIA IN THE NEARSHORE WATERS. ONCE THE SFC LOW MOVES NORTH
OF THE UPPER MICHIGAN, THE PRESSURE GRADIENT WILL TIGHTEN BRIEFLY
OVER THE UPPER GREAT LAKES BRINGING SMALL CRAFT CRITERIA TO MOST, IF
NOT ALL OF THE NEARSHORES MONDAY AFTERNOON AND MONDAY NIGHT.
TUESDAY, AS THE SFC LOW STALLS NORTH OF LAKE SUPERIOR, THE WINDS
WILL INCREASE AS THE GRADIENT AGAIN TIGHTENS, AND THEN RELAXES BY
THE AFTERNOON.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LSZ321-322.

&&

$$

UPDATE...JAZ
NEAR TERM...JSL
SHORT TERM...JPB
LONG TERM...GILLEN
AVIATION...JAZ
MARINE...JSL



000
FXUS63 KGRR 200017
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
817 PM EDT SUN APR 19 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 258 PM EDT SUN APR 19 2015

A MAJOR CHANGE IN THE OVERALL WEATHER PATTERN IS ABOUT TO BEGIN. A
STRONG AND DEEPENING LOW PRESSURE SYSTEM WILL TRACK NORTHWARD
THROUGH WESTERN LOWER MICHIGAN TONIGHT BRINGING RAIN THAT MAY BE
HEAVY AT TIMES EARLY TONIGHT. AFTER THE SYSTEM MOVES NORTH OF THE
AREA LATER TONIGHT THE RAIN WILL DIMINISH TO SHOWERS BUT IT WILL
BE BREEZY. THEN SHOWERS AND BREEZY CONDITIONS WILL CONTINUE INTO
TUESDAY. BY TUESDAY NIGHT IT WILL GET COLD ENOUGH FOR SNOW TO MIX
WITH THE RAIN. THAT WILL CONTINUE INTO THURSDAY. IT WILL BE MUCH
COOLER THROUGH THIS ENTIRE PERIOD WITH HIGHS TUESDAY THROUGH
THURSDAY IN THE 40S AND LOWS NEAR FREEZING.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 258 PM EDT SUN APR 19 2015

THE PRIMARY ISSUE IS THE RAIN TONIGHT...THEN WINDY AND SHOWERS
MONDAY INTO TUESDAY. THERE IS A GOOD CHANCE OF MEASURABLE SNOW
OVER NORTHERN SECTIONS TUESDAY NIGHT.

THE DEEPENING STORM SYSTEM WILL TRACK THROUGH WESTERN LOWER
MICHIGAN TONIGHT BRINGING A PERIOD OF MODERATE TO HEAVY RAIN THAT
WILL LAST AROUND 6 HOURS IN ANY ONE PLACE. IT WILL BE BREEZY AT
FIRST BUT WINDS WILL DIMINISH TOWARD MIDNIGHT AS THE SURFACE LOW
MOVES THROUGH THE AREA.

THE RAIN EVENT TONIGHT REMAINS WELL SUPPORTED BY ALL THE MODELS.
THERE IS SOME ISSUE AS TO WHERE THE HEAVIEST RAIN WILL ACTUALLY
FALL BUT ALL AREAS GET AT LEAST A THIRD OF AN INCH AND MOST AREAS
SHOULD GET MORE THAN A HALF INCH OF RAIN TONIGHT. THIS IS ALL THE
RESULT OF UPPER WAVE THAT GOES NEGATIVE TILT OVER SOUTHWEST
MICHIGAN TONIGHT. THAT CAUSES THE SURFACE LOW TO TRACK NORTHWARD
AND DEEPEN RAPIDLY. ALSO THIS RESULTS IN A STRONG LOW LEVEL JET
(60 KNOTS)... STRONG 1000 TO 850 MOISTURE CONVERGENCE AIMED AT
SOUTHWEST LOWER MICHIGAN THIS EVENING AND CONDENSATION PRESSURE
DEFICITS NEAR ZERO MB THIS EVENING. THERE IS ALSO 40 KNOT OF WIND
PERPENDICULAR TO THE ISOTROPIC SURFACES EARLY TONIGHT... AND WE
CAN ALL ADD TO THAT PRECIPITATION WATER VALUES (1.4") NEAR 2
STANDARD DEVIATIONS FROM NORMAL AND MIXING RATIOS RISING TO NEAR 8
G/KG FROM UNDER 2 G/KG THIS MORNING. THERE IS ALSO A ZONE OF
STRONG MID-LEVEL FGEN JUST AHEAD OF THE SYSTEM AS IT MOVES THROUGH
SOUTHWEST MICHIGAN TONIGHT. BOTTOM LINE... IT WOULD BE HARD TO
IMAGINE WE WILL NOT GET RAIN OVERNIGHT.

ONCE THE LOW PASSES US THE SIGNIFICANT RAINFALL WILL END. HOWEVER
THE SECONDARY COLD FRONT AND TRAILING NORTHERN STREAM WAVE WILL
BRING ANOTHER PERIOD OF SHOWERS TO THE AREA MIDDAY MONDAY INTO
EARLY EVENING. THAT BRINGS IN THE TRULY COLDER AIR.

MONDAY NIGHT WE MAY SEE A BREAK IN THE SHOWERS EARLY ON BUT THEN
THE WRAP AROUND MOISTURE MOVES IN AND WE SEE SHOWERS THAT MAY MIX
WITH AN CHANGE TO SNOW SHOWERS BY TUESDAY NIGHT. BY THE WAY THE
SPC SOUNDING CLIMATOLOGY PAGE SHOWS THE COLDEST 850 TEMPERATURE
FOR THE DTX SOUNDING TO BE -12C ON THE 22ND. THE ECWMF SHOWS -9.8C
AT 2 PM WEDNESDAY NEAR GRR. TO SAY THE LEAST...IT WILL GET COLDER
THIS COMING WEEK!

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

UNSEASONABLY COLD WEATHER IS ANTICIPATED WEDNESDAY AND THURSDAY WITH
DEEP CYCLONIC FLOW AND COLD AIR ADVECTION WITH THE UPPER LEVEL LOW
STILL IN PLACE OVER THE NORTHERN GREAT LAKES REGION. SCATTERED RAIN
SHOWERS WILL CONTINUE AND MAY BE MIXED AT TIMES WITH WET SNOW FLAKES
ESPECIALLY OVER RELATIVELY HIGHER ELEVATIONS OF OUR NORTHERN FCST
AREA.

TEMPERATURES SHOULD MODERATE SLIGHTLY FRIDAY THROUGH THE WEEKEND BUT
WILL STILL AVERAGE SEVERAL DEGREES BELOW NORMAL. THIS AS A SFC RIDGE
BUILDS IN AND AS THE UPPER LEVEL LOW MOVES MUCH FURTHER EAST TO THE
NEW ENGLAND REGION BY THEN. THE RIDGE WILL BRING FAIR AND SEASONABLY
COOL WEATHER FRIDAY THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 817 PM EDT SUN APR 19 2015

AVIATION CONDITIONS WILL CONTINUE TO DETERIORATE THIS EVENING WITH
MVFR AND IFR WEATHER DEVELOPING. BY MIDNIGHT OR A LITTLE BIT
AFTER...ALL SITES SHOULD HAVE IFR CEILINGS. THE STEADIER RAIN WILL
CONTINUE THROUGH ABOUT 100AM...THEN BECOME MORE SCATTERED
OVERNIGHT. THE LOW CEILINGS WILL PERSIST RIGHT INTO THE MORNING
HOURS OF MONDAY...WITH IFR AND LIFR CEILINGS PREVALENT INTO MID
MORNING. CONDITIONS SHOULD BEGIN TO IMPROVE MONDAY AFTERNOON AS
THE IFR CEILINGS TRY TO LIFT TO MVFR.

IT WILL BE BREEZY OUT OF THE EAST THIS EVENING AND THEN TURNING
WINDY MONDAY AFTERNOON FROM THE SOUTHWEST BEHIND A COLD FRONT.


&&

.MARINE...
ISSUED AT 258 PM EDT SUN APR 19 2015

I EXTENDED THE SCA THROUGH TUESDAY AFTERNOON FOR THE ALL THE ZONES
FROM WHITEHALL SOUTH ( NORTH OF THERE WINDS WILL NOT BE AS STRONG
OVERNIGHT). AFTER THE SURFACE LOW MOVES NORTH OF MUSKEGON WINDS WILL
INCREASE TO 30 KNOTS FROM THE SOUTHWEST THEN I EXPECT 15 TO 25
KNOT WINDS MONDAY INTO TUESDAY. AS THE COLD AIR COMES IN WAVES
WILL BUILD SO WE WILL LIKELY NEED A SCA FOR THE NORTHERN TWO ZONE
GROUPS MONDAY NIGHT AND TUESDAY.


&&

.HYDROLOGY...
ISSUED AT 1114 AM EDT SUN APR 19 2015

PERIODS OF RAIN ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON AND
AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. THE LIGHTER VARIETY OF
PRECIPITATION MAY EXTENT INTO MIDWEEK. THOUGH WE WILL SEE A DECENT SOIL
SOAKING IT SHOULD NOT BE SUBSTANTIAL ENOUGH TO CREATE FLOODING
CONCERNS. GRADUAL BUT MINOR RISES ARE LIKELY...SUSPECTING THAT
THIS WOULD STAY WITHIN BANKS FOR MOST LOCATIONS. I WOULD NOT RULE
OUT A COUPLE OF SITES FLIRTING WITH ADVISORY STAGE AS WE GO INTO
TUESDAY...ESPECIALLY IF ANY MODERATE RAINFALL IS MORE PERSISTENT
WITH THE FIRST COUPLE OF ROUNDS OF MOISTURE. OTHERWISE...AREA
RIVERS ARE WELL BEHAVED THROUGH THE PERIOD.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...DUKE
HYDROLOGY...JAM
MARINE...WDM






000
FXUS63 KGRR 200017
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
817 PM EDT SUN APR 19 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 258 PM EDT SUN APR 19 2015

A MAJOR CHANGE IN THE OVERALL WEATHER PATTERN IS ABOUT TO BEGIN. A
STRONG AND DEEPENING LOW PRESSURE SYSTEM WILL TRACK NORTHWARD
THROUGH WESTERN LOWER MICHIGAN TONIGHT BRINGING RAIN THAT MAY BE
HEAVY AT TIMES EARLY TONIGHT. AFTER THE SYSTEM MOVES NORTH OF THE
AREA LATER TONIGHT THE RAIN WILL DIMINISH TO SHOWERS BUT IT WILL
BE BREEZY. THEN SHOWERS AND BREEZY CONDITIONS WILL CONTINUE INTO
TUESDAY. BY TUESDAY NIGHT IT WILL GET COLD ENOUGH FOR SNOW TO MIX
WITH THE RAIN. THAT WILL CONTINUE INTO THURSDAY. IT WILL BE MUCH
COOLER THROUGH THIS ENTIRE PERIOD WITH HIGHS TUESDAY THROUGH
THURSDAY IN THE 40S AND LOWS NEAR FREEZING.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 258 PM EDT SUN APR 19 2015

THE PRIMARY ISSUE IS THE RAIN TONIGHT...THEN WINDY AND SHOWERS
MONDAY INTO TUESDAY. THERE IS A GOOD CHANCE OF MEASURABLE SNOW
OVER NORTHERN SECTIONS TUESDAY NIGHT.

THE DEEPENING STORM SYSTEM WILL TRACK THROUGH WESTERN LOWER
MICHIGAN TONIGHT BRINGING A PERIOD OF MODERATE TO HEAVY RAIN THAT
WILL LAST AROUND 6 HOURS IN ANY ONE PLACE. IT WILL BE BREEZY AT
FIRST BUT WINDS WILL DIMINISH TOWARD MIDNIGHT AS THE SURFACE LOW
MOVES THROUGH THE AREA.

THE RAIN EVENT TONIGHT REMAINS WELL SUPPORTED BY ALL THE MODELS.
THERE IS SOME ISSUE AS TO WHERE THE HEAVIEST RAIN WILL ACTUALLY
FALL BUT ALL AREAS GET AT LEAST A THIRD OF AN INCH AND MOST AREAS
SHOULD GET MORE THAN A HALF INCH OF RAIN TONIGHT. THIS IS ALL THE
RESULT OF UPPER WAVE THAT GOES NEGATIVE TILT OVER SOUTHWEST
MICHIGAN TONIGHT. THAT CAUSES THE SURFACE LOW TO TRACK NORTHWARD
AND DEEPEN RAPIDLY. ALSO THIS RESULTS IN A STRONG LOW LEVEL JET
(60 KNOTS)... STRONG 1000 TO 850 MOISTURE CONVERGENCE AIMED AT
SOUTHWEST LOWER MICHIGAN THIS EVENING AND CONDENSATION PRESSURE
DEFICITS NEAR ZERO MB THIS EVENING. THERE IS ALSO 40 KNOT OF WIND
PERPENDICULAR TO THE ISOTROPIC SURFACES EARLY TONIGHT... AND WE
CAN ALL ADD TO THAT PRECIPITATION WATER VALUES (1.4") NEAR 2
STANDARD DEVIATIONS FROM NORMAL AND MIXING RATIOS RISING TO NEAR 8
G/KG FROM UNDER 2 G/KG THIS MORNING. THERE IS ALSO A ZONE OF
STRONG MID-LEVEL FGEN JUST AHEAD OF THE SYSTEM AS IT MOVES THROUGH
SOUTHWEST MICHIGAN TONIGHT. BOTTOM LINE... IT WOULD BE HARD TO
IMAGINE WE WILL NOT GET RAIN OVERNIGHT.

ONCE THE LOW PASSES US THE SIGNIFICANT RAINFALL WILL END. HOWEVER
THE SECONDARY COLD FRONT AND TRAILING NORTHERN STREAM WAVE WILL
BRING ANOTHER PERIOD OF SHOWERS TO THE AREA MIDDAY MONDAY INTO
EARLY EVENING. THAT BRINGS IN THE TRULY COLDER AIR.

MONDAY NIGHT WE MAY SEE A BREAK IN THE SHOWERS EARLY ON BUT THEN
THE WRAP AROUND MOISTURE MOVES IN AND WE SEE SHOWERS THAT MAY MIX
WITH AN CHANGE TO SNOW SHOWERS BY TUESDAY NIGHT. BY THE WAY THE
SPC SOUNDING CLIMATOLOGY PAGE SHOWS THE COLDEST 850 TEMPERATURE
FOR THE DTX SOUNDING TO BE -12C ON THE 22ND. THE ECWMF SHOWS -9.8C
AT 2 PM WEDNESDAY NEAR GRR. TO SAY THE LEAST...IT WILL GET COLDER
THIS COMING WEEK!

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

UNSEASONABLY COLD WEATHER IS ANTICIPATED WEDNESDAY AND THURSDAY WITH
DEEP CYCLONIC FLOW AND COLD AIR ADVECTION WITH THE UPPER LEVEL LOW
STILL IN PLACE OVER THE NORTHERN GREAT LAKES REGION. SCATTERED RAIN
SHOWERS WILL CONTINUE AND MAY BE MIXED AT TIMES WITH WET SNOW FLAKES
ESPECIALLY OVER RELATIVELY HIGHER ELEVATIONS OF OUR NORTHERN FCST
AREA.

TEMPERATURES SHOULD MODERATE SLIGHTLY FRIDAY THROUGH THE WEEKEND BUT
WILL STILL AVERAGE SEVERAL DEGREES BELOW NORMAL. THIS AS A SFC RIDGE
BUILDS IN AND AS THE UPPER LEVEL LOW MOVES MUCH FURTHER EAST TO THE
NEW ENGLAND REGION BY THEN. THE RIDGE WILL BRING FAIR AND SEASONABLY
COOL WEATHER FRIDAY THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 817 PM EDT SUN APR 19 2015

AVIATION CONDITIONS WILL CONTINUE TO DETERIORATE THIS EVENING WITH
MVFR AND IFR WEATHER DEVELOPING. BY MIDNIGHT OR A LITTLE BIT
AFTER...ALL SITES SHOULD HAVE IFR CEILINGS. THE STEADIER RAIN WILL
CONTINUE THROUGH ABOUT 100AM...THEN BECOME MORE SCATTERED
OVERNIGHT. THE LOW CEILINGS WILL PERSIST RIGHT INTO THE MORNING
HOURS OF MONDAY...WITH IFR AND LIFR CEILINGS PREVALENT INTO MID
MORNING. CONDITIONS SHOULD BEGIN TO IMPROVE MONDAY AFTERNOON AS
THE IFR CEILINGS TRY TO LIFT TO MVFR.

IT WILL BE BREEZY OUT OF THE EAST THIS EVENING AND THEN TURNING
WINDY MONDAY AFTERNOON FROM THE SOUTHWEST BEHIND A COLD FRONT.


&&

.MARINE...
ISSUED AT 258 PM EDT SUN APR 19 2015

I EXTENDED THE SCA THROUGH TUESDAY AFTERNOON FOR THE ALL THE ZONES
FROM WHITEHALL SOUTH ( NORTH OF THERE WINDS WILL NOT BE AS STRONG
OVERNIGHT). AFTER THE SURFACE LOW MOVES NORTH OF MUSKEGON WINDS WILL
INCREASE TO 30 KNOTS FROM THE SOUTHWEST THEN I EXPECT 15 TO 25
KNOT WINDS MONDAY INTO TUESDAY. AS THE COLD AIR COMES IN WAVES
WILL BUILD SO WE WILL LIKELY NEED A SCA FOR THE NORTHERN TWO ZONE
GROUPS MONDAY NIGHT AND TUESDAY.


&&

.HYDROLOGY...
ISSUED AT 1114 AM EDT SUN APR 19 2015

PERIODS OF RAIN ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON AND
AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. THE LIGHTER VARIETY OF
PRECIPITATION MAY EXTENT INTO MIDWEEK. THOUGH WE WILL SEE A DECENT SOIL
SOAKING IT SHOULD NOT BE SUBSTANTIAL ENOUGH TO CREATE FLOODING
CONCERNS. GRADUAL BUT MINOR RISES ARE LIKELY...SUSPECTING THAT
THIS WOULD STAY WITHIN BANKS FOR MOST LOCATIONS. I WOULD NOT RULE
OUT A COUPLE OF SITES FLIRTING WITH ADVISORY STAGE AS WE GO INTO
TUESDAY...ESPECIALLY IF ANY MODERATE RAINFALL IS MORE PERSISTENT
WITH THE FIRST COUPLE OF ROUNDS OF MOISTURE. OTHERWISE...AREA
RIVERS ARE WELL BEHAVED THROUGH THE PERIOD.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...DUKE
HYDROLOGY...JAM
MARINE...WDM







000
FXUS63 KGRR 200017
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
817 PM EDT SUN APR 19 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 258 PM EDT SUN APR 19 2015

A MAJOR CHANGE IN THE OVERALL WEATHER PATTERN IS ABOUT TO BEGIN. A
STRONG AND DEEPENING LOW PRESSURE SYSTEM WILL TRACK NORTHWARD
THROUGH WESTERN LOWER MICHIGAN TONIGHT BRINGING RAIN THAT MAY BE
HEAVY AT TIMES EARLY TONIGHT. AFTER THE SYSTEM MOVES NORTH OF THE
AREA LATER TONIGHT THE RAIN WILL DIMINISH TO SHOWERS BUT IT WILL
BE BREEZY. THEN SHOWERS AND BREEZY CONDITIONS WILL CONTINUE INTO
TUESDAY. BY TUESDAY NIGHT IT WILL GET COLD ENOUGH FOR SNOW TO MIX
WITH THE RAIN. THAT WILL CONTINUE INTO THURSDAY. IT WILL BE MUCH
COOLER THROUGH THIS ENTIRE PERIOD WITH HIGHS TUESDAY THROUGH
THURSDAY IN THE 40S AND LOWS NEAR FREEZING.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 258 PM EDT SUN APR 19 2015

THE PRIMARY ISSUE IS THE RAIN TONIGHT...THEN WINDY AND SHOWERS
MONDAY INTO TUESDAY. THERE IS A GOOD CHANCE OF MEASURABLE SNOW
OVER NORTHERN SECTIONS TUESDAY NIGHT.

THE DEEPENING STORM SYSTEM WILL TRACK THROUGH WESTERN LOWER
MICHIGAN TONIGHT BRINGING A PERIOD OF MODERATE TO HEAVY RAIN THAT
WILL LAST AROUND 6 HOURS IN ANY ONE PLACE. IT WILL BE BREEZY AT
FIRST BUT WINDS WILL DIMINISH TOWARD MIDNIGHT AS THE SURFACE LOW
MOVES THROUGH THE AREA.

THE RAIN EVENT TONIGHT REMAINS WELL SUPPORTED BY ALL THE MODELS.
THERE IS SOME ISSUE AS TO WHERE THE HEAVIEST RAIN WILL ACTUALLY
FALL BUT ALL AREAS GET AT LEAST A THIRD OF AN INCH AND MOST AREAS
SHOULD GET MORE THAN A HALF INCH OF RAIN TONIGHT. THIS IS ALL THE
RESULT OF UPPER WAVE THAT GOES NEGATIVE TILT OVER SOUTHWEST
MICHIGAN TONIGHT. THAT CAUSES THE SURFACE LOW TO TRACK NORTHWARD
AND DEEPEN RAPIDLY. ALSO THIS RESULTS IN A STRONG LOW LEVEL JET
(60 KNOTS)... STRONG 1000 TO 850 MOISTURE CONVERGENCE AIMED AT
SOUTHWEST LOWER MICHIGAN THIS EVENING AND CONDENSATION PRESSURE
DEFICITS NEAR ZERO MB THIS EVENING. THERE IS ALSO 40 KNOT OF WIND
PERPENDICULAR TO THE ISOTROPIC SURFACES EARLY TONIGHT... AND WE
CAN ALL ADD TO THAT PRECIPITATION WATER VALUES (1.4") NEAR 2
STANDARD DEVIATIONS FROM NORMAL AND MIXING RATIOS RISING TO NEAR 8
G/KG FROM UNDER 2 G/KG THIS MORNING. THERE IS ALSO A ZONE OF
STRONG MID-LEVEL FGEN JUST AHEAD OF THE SYSTEM AS IT MOVES THROUGH
SOUTHWEST MICHIGAN TONIGHT. BOTTOM LINE... IT WOULD BE HARD TO
IMAGINE WE WILL NOT GET RAIN OVERNIGHT.

ONCE THE LOW PASSES US THE SIGNIFICANT RAINFALL WILL END. HOWEVER
THE SECONDARY COLD FRONT AND TRAILING NORTHERN STREAM WAVE WILL
BRING ANOTHER PERIOD OF SHOWERS TO THE AREA MIDDAY MONDAY INTO
EARLY EVENING. THAT BRINGS IN THE TRULY COLDER AIR.

MONDAY NIGHT WE MAY SEE A BREAK IN THE SHOWERS EARLY ON BUT THEN
THE WRAP AROUND MOISTURE MOVES IN AND WE SEE SHOWERS THAT MAY MIX
WITH AN CHANGE TO SNOW SHOWERS BY TUESDAY NIGHT. BY THE WAY THE
SPC SOUNDING CLIMATOLOGY PAGE SHOWS THE COLDEST 850 TEMPERATURE
FOR THE DTX SOUNDING TO BE -12C ON THE 22ND. THE ECWMF SHOWS -9.8C
AT 2 PM WEDNESDAY NEAR GRR. TO SAY THE LEAST...IT WILL GET COLDER
THIS COMING WEEK!

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

UNSEASONABLY COLD WEATHER IS ANTICIPATED WEDNESDAY AND THURSDAY WITH
DEEP CYCLONIC FLOW AND COLD AIR ADVECTION WITH THE UPPER LEVEL LOW
STILL IN PLACE OVER THE NORTHERN GREAT LAKES REGION. SCATTERED RAIN
SHOWERS WILL CONTINUE AND MAY BE MIXED AT TIMES WITH WET SNOW FLAKES
ESPECIALLY OVER RELATIVELY HIGHER ELEVATIONS OF OUR NORTHERN FCST
AREA.

TEMPERATURES SHOULD MODERATE SLIGHTLY FRIDAY THROUGH THE WEEKEND BUT
WILL STILL AVERAGE SEVERAL DEGREES BELOW NORMAL. THIS AS A SFC RIDGE
BUILDS IN AND AS THE UPPER LEVEL LOW MOVES MUCH FURTHER EAST TO THE
NEW ENGLAND REGION BY THEN. THE RIDGE WILL BRING FAIR AND SEASONABLY
COOL WEATHER FRIDAY THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 817 PM EDT SUN APR 19 2015

AVIATION CONDITIONS WILL CONTINUE TO DETERIORATE THIS EVENING WITH
MVFR AND IFR WEATHER DEVELOPING. BY MIDNIGHT OR A LITTLE BIT
AFTER...ALL SITES SHOULD HAVE IFR CEILINGS. THE STEADIER RAIN WILL
CONTINUE THROUGH ABOUT 100AM...THEN BECOME MORE SCATTERED
OVERNIGHT. THE LOW CEILINGS WILL PERSIST RIGHT INTO THE MORNING
HOURS OF MONDAY...WITH IFR AND LIFR CEILINGS PREVALENT INTO MID
MORNING. CONDITIONS SHOULD BEGIN TO IMPROVE MONDAY AFTERNOON AS
THE IFR CEILINGS TRY TO LIFT TO MVFR.

IT WILL BE BREEZY OUT OF THE EAST THIS EVENING AND THEN TURNING
WINDY MONDAY AFTERNOON FROM THE SOUTHWEST BEHIND A COLD FRONT.


&&

.MARINE...
ISSUED AT 258 PM EDT SUN APR 19 2015

I EXTENDED THE SCA THROUGH TUESDAY AFTERNOON FOR THE ALL THE ZONES
FROM WHITEHALL SOUTH ( NORTH OF THERE WINDS WILL NOT BE AS STRONG
OVERNIGHT). AFTER THE SURFACE LOW MOVES NORTH OF MUSKEGON WINDS WILL
INCREASE TO 30 KNOTS FROM THE SOUTHWEST THEN I EXPECT 15 TO 25
KNOT WINDS MONDAY INTO TUESDAY. AS THE COLD AIR COMES IN WAVES
WILL BUILD SO WE WILL LIKELY NEED A SCA FOR THE NORTHERN TWO ZONE
GROUPS MONDAY NIGHT AND TUESDAY.


&&

.HYDROLOGY...
ISSUED AT 1114 AM EDT SUN APR 19 2015

PERIODS OF RAIN ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON AND
AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. THE LIGHTER VARIETY OF
PRECIPITATION MAY EXTENT INTO MIDWEEK. THOUGH WE WILL SEE A DECENT SOIL
SOAKING IT SHOULD NOT BE SUBSTANTIAL ENOUGH TO CREATE FLOODING
CONCERNS. GRADUAL BUT MINOR RISES ARE LIKELY...SUSPECTING THAT
THIS WOULD STAY WITHIN BANKS FOR MOST LOCATIONS. I WOULD NOT RULE
OUT A COUPLE OF SITES FLIRTING WITH ADVISORY STAGE AS WE GO INTO
TUESDAY...ESPECIALLY IF ANY MODERATE RAINFALL IS MORE PERSISTENT
WITH THE FIRST COUPLE OF ROUNDS OF MOISTURE. OTHERWISE...AREA
RIVERS ARE WELL BEHAVED THROUGH THE PERIOD.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...DUKE
HYDROLOGY...JAM
MARINE...WDM







000
FXUS63 KGRR 200017
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
817 PM EDT SUN APR 19 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 258 PM EDT SUN APR 19 2015

A MAJOR CHANGE IN THE OVERALL WEATHER PATTERN IS ABOUT TO BEGIN. A
STRONG AND DEEPENING LOW PRESSURE SYSTEM WILL TRACK NORTHWARD
THROUGH WESTERN LOWER MICHIGAN TONIGHT BRINGING RAIN THAT MAY BE
HEAVY AT TIMES EARLY TONIGHT. AFTER THE SYSTEM MOVES NORTH OF THE
AREA LATER TONIGHT THE RAIN WILL DIMINISH TO SHOWERS BUT IT WILL
BE BREEZY. THEN SHOWERS AND BREEZY CONDITIONS WILL CONTINUE INTO
TUESDAY. BY TUESDAY NIGHT IT WILL GET COLD ENOUGH FOR SNOW TO MIX
WITH THE RAIN. THAT WILL CONTINUE INTO THURSDAY. IT WILL BE MUCH
COOLER THROUGH THIS ENTIRE PERIOD WITH HIGHS TUESDAY THROUGH
THURSDAY IN THE 40S AND LOWS NEAR FREEZING.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 258 PM EDT SUN APR 19 2015

THE PRIMARY ISSUE IS THE RAIN TONIGHT...THEN WINDY AND SHOWERS
MONDAY INTO TUESDAY. THERE IS A GOOD CHANCE OF MEASURABLE SNOW
OVER NORTHERN SECTIONS TUESDAY NIGHT.

THE DEEPENING STORM SYSTEM WILL TRACK THROUGH WESTERN LOWER
MICHIGAN TONIGHT BRINGING A PERIOD OF MODERATE TO HEAVY RAIN THAT
WILL LAST AROUND 6 HOURS IN ANY ONE PLACE. IT WILL BE BREEZY AT
FIRST BUT WINDS WILL DIMINISH TOWARD MIDNIGHT AS THE SURFACE LOW
MOVES THROUGH THE AREA.

THE RAIN EVENT TONIGHT REMAINS WELL SUPPORTED BY ALL THE MODELS.
THERE IS SOME ISSUE AS TO WHERE THE HEAVIEST RAIN WILL ACTUALLY
FALL BUT ALL AREAS GET AT LEAST A THIRD OF AN INCH AND MOST AREAS
SHOULD GET MORE THAN A HALF INCH OF RAIN TONIGHT. THIS IS ALL THE
RESULT OF UPPER WAVE THAT GOES NEGATIVE TILT OVER SOUTHWEST
MICHIGAN TONIGHT. THAT CAUSES THE SURFACE LOW TO TRACK NORTHWARD
AND DEEPEN RAPIDLY. ALSO THIS RESULTS IN A STRONG LOW LEVEL JET
(60 KNOTS)... STRONG 1000 TO 850 MOISTURE CONVERGENCE AIMED AT
SOUTHWEST LOWER MICHIGAN THIS EVENING AND CONDENSATION PRESSURE
DEFICITS NEAR ZERO MB THIS EVENING. THERE IS ALSO 40 KNOT OF WIND
PERPENDICULAR TO THE ISOTROPIC SURFACES EARLY TONIGHT... AND WE
CAN ALL ADD TO THAT PRECIPITATION WATER VALUES (1.4") NEAR 2
STANDARD DEVIATIONS FROM NORMAL AND MIXING RATIOS RISING TO NEAR 8
G/KG FROM UNDER 2 G/KG THIS MORNING. THERE IS ALSO A ZONE OF
STRONG MID-LEVEL FGEN JUST AHEAD OF THE SYSTEM AS IT MOVES THROUGH
SOUTHWEST MICHIGAN TONIGHT. BOTTOM LINE... IT WOULD BE HARD TO
IMAGINE WE WILL NOT GET RAIN OVERNIGHT.

ONCE THE LOW PASSES US THE SIGNIFICANT RAINFALL WILL END. HOWEVER
THE SECONDARY COLD FRONT AND TRAILING NORTHERN STREAM WAVE WILL
BRING ANOTHER PERIOD OF SHOWERS TO THE AREA MIDDAY MONDAY INTO
EARLY EVENING. THAT BRINGS IN THE TRULY COLDER AIR.

MONDAY NIGHT WE MAY SEE A BREAK IN THE SHOWERS EARLY ON BUT THEN
THE WRAP AROUND MOISTURE MOVES IN AND WE SEE SHOWERS THAT MAY MIX
WITH AN CHANGE TO SNOW SHOWERS BY TUESDAY NIGHT. BY THE WAY THE
SPC SOUNDING CLIMATOLOGY PAGE SHOWS THE COLDEST 850 TEMPERATURE
FOR THE DTX SOUNDING TO BE -12C ON THE 22ND. THE ECWMF SHOWS -9.8C
AT 2 PM WEDNESDAY NEAR GRR. TO SAY THE LEAST...IT WILL GET COLDER
THIS COMING WEEK!

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

UNSEASONABLY COLD WEATHER IS ANTICIPATED WEDNESDAY AND THURSDAY WITH
DEEP CYCLONIC FLOW AND COLD AIR ADVECTION WITH THE UPPER LEVEL LOW
STILL IN PLACE OVER THE NORTHERN GREAT LAKES REGION. SCATTERED RAIN
SHOWERS WILL CONTINUE AND MAY BE MIXED AT TIMES WITH WET SNOW FLAKES
ESPECIALLY OVER RELATIVELY HIGHER ELEVATIONS OF OUR NORTHERN FCST
AREA.

TEMPERATURES SHOULD MODERATE SLIGHTLY FRIDAY THROUGH THE WEEKEND BUT
WILL STILL AVERAGE SEVERAL DEGREES BELOW NORMAL. THIS AS A SFC RIDGE
BUILDS IN AND AS THE UPPER LEVEL LOW MOVES MUCH FURTHER EAST TO THE
NEW ENGLAND REGION BY THEN. THE RIDGE WILL BRING FAIR AND SEASONABLY
COOL WEATHER FRIDAY THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 817 PM EDT SUN APR 19 2015

AVIATION CONDITIONS WILL CONTINUE TO DETERIORATE THIS EVENING WITH
MVFR AND IFR WEATHER DEVELOPING. BY MIDNIGHT OR A LITTLE BIT
AFTER...ALL SITES SHOULD HAVE IFR CEILINGS. THE STEADIER RAIN WILL
CONTINUE THROUGH ABOUT 100AM...THEN BECOME MORE SCATTERED
OVERNIGHT. THE LOW CEILINGS WILL PERSIST RIGHT INTO THE MORNING
HOURS OF MONDAY...WITH IFR AND LIFR CEILINGS PREVALENT INTO MID
MORNING. CONDITIONS SHOULD BEGIN TO IMPROVE MONDAY AFTERNOON AS
THE IFR CEILINGS TRY TO LIFT TO MVFR.

IT WILL BE BREEZY OUT OF THE EAST THIS EVENING AND THEN TURNING
WINDY MONDAY AFTERNOON FROM THE SOUTHWEST BEHIND A COLD FRONT.


&&

.MARINE...
ISSUED AT 258 PM EDT SUN APR 19 2015

I EXTENDED THE SCA THROUGH TUESDAY AFTERNOON FOR THE ALL THE ZONES
FROM WHITEHALL SOUTH ( NORTH OF THERE WINDS WILL NOT BE AS STRONG
OVERNIGHT). AFTER THE SURFACE LOW MOVES NORTH OF MUSKEGON WINDS WILL
INCREASE TO 30 KNOTS FROM THE SOUTHWEST THEN I EXPECT 15 TO 25
KNOT WINDS MONDAY INTO TUESDAY. AS THE COLD AIR COMES IN WAVES
WILL BUILD SO WE WILL LIKELY NEED A SCA FOR THE NORTHERN TWO ZONE
GROUPS MONDAY NIGHT AND TUESDAY.


&&

.HYDROLOGY...
ISSUED AT 1114 AM EDT SUN APR 19 2015

PERIODS OF RAIN ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON AND
AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. THE LIGHTER VARIETY OF
PRECIPITATION MAY EXTENT INTO MIDWEEK. THOUGH WE WILL SEE A DECENT SOIL
SOAKING IT SHOULD NOT BE SUBSTANTIAL ENOUGH TO CREATE FLOODING
CONCERNS. GRADUAL BUT MINOR RISES ARE LIKELY...SUSPECTING THAT
THIS WOULD STAY WITHIN BANKS FOR MOST LOCATIONS. I WOULD NOT RULE
OUT A COUPLE OF SITES FLIRTING WITH ADVISORY STAGE AS WE GO INTO
TUESDAY...ESPECIALLY IF ANY MODERATE RAINFALL IS MORE PERSISTENT
WITH THE FIRST COUPLE OF ROUNDS OF MOISTURE. OTHERWISE...AREA
RIVERS ARE WELL BEHAVED THROUGH THE PERIOD.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...DUKE
HYDROLOGY...JAM
MARINE...WDM







000
FXUS63 KGRR 200017
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
817 PM EDT SUN APR 19 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 258 PM EDT SUN APR 19 2015

A MAJOR CHANGE IN THE OVERALL WEATHER PATTERN IS ABOUT TO BEGIN. A
STRONG AND DEEPENING LOW PRESSURE SYSTEM WILL TRACK NORTHWARD
THROUGH WESTERN LOWER MICHIGAN TONIGHT BRINGING RAIN THAT MAY BE
HEAVY AT TIMES EARLY TONIGHT. AFTER THE SYSTEM MOVES NORTH OF THE
AREA LATER TONIGHT THE RAIN WILL DIMINISH TO SHOWERS BUT IT WILL
BE BREEZY. THEN SHOWERS AND BREEZY CONDITIONS WILL CONTINUE INTO
TUESDAY. BY TUESDAY NIGHT IT WILL GET COLD ENOUGH FOR SNOW TO MIX
WITH THE RAIN. THAT WILL CONTINUE INTO THURSDAY. IT WILL BE MUCH
COOLER THROUGH THIS ENTIRE PERIOD WITH HIGHS TUESDAY THROUGH
THURSDAY IN THE 40S AND LOWS NEAR FREEZING.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 258 PM EDT SUN APR 19 2015

THE PRIMARY ISSUE IS THE RAIN TONIGHT...THEN WINDY AND SHOWERS
MONDAY INTO TUESDAY. THERE IS A GOOD CHANCE OF MEASURABLE SNOW
OVER NORTHERN SECTIONS TUESDAY NIGHT.

THE DEEPENING STORM SYSTEM WILL TRACK THROUGH WESTERN LOWER
MICHIGAN TONIGHT BRINGING A PERIOD OF MODERATE TO HEAVY RAIN THAT
WILL LAST AROUND 6 HOURS IN ANY ONE PLACE. IT WILL BE BREEZY AT
FIRST BUT WINDS WILL DIMINISH TOWARD MIDNIGHT AS THE SURFACE LOW
MOVES THROUGH THE AREA.

THE RAIN EVENT TONIGHT REMAINS WELL SUPPORTED BY ALL THE MODELS.
THERE IS SOME ISSUE AS TO WHERE THE HEAVIEST RAIN WILL ACTUALLY
FALL BUT ALL AREAS GET AT LEAST A THIRD OF AN INCH AND MOST AREAS
SHOULD GET MORE THAN A HALF INCH OF RAIN TONIGHT. THIS IS ALL THE
RESULT OF UPPER WAVE THAT GOES NEGATIVE TILT OVER SOUTHWEST
MICHIGAN TONIGHT. THAT CAUSES THE SURFACE LOW TO TRACK NORTHWARD
AND DEEPEN RAPIDLY. ALSO THIS RESULTS IN A STRONG LOW LEVEL JET
(60 KNOTS)... STRONG 1000 TO 850 MOISTURE CONVERGENCE AIMED AT
SOUTHWEST LOWER MICHIGAN THIS EVENING AND CONDENSATION PRESSURE
DEFICITS NEAR ZERO MB THIS EVENING. THERE IS ALSO 40 KNOT OF WIND
PERPENDICULAR TO THE ISOTROPIC SURFACES EARLY TONIGHT... AND WE
CAN ALL ADD TO THAT PRECIPITATION WATER VALUES (1.4") NEAR 2
STANDARD DEVIATIONS FROM NORMAL AND MIXING RATIOS RISING TO NEAR 8
G/KG FROM UNDER 2 G/KG THIS MORNING. THERE IS ALSO A ZONE OF
STRONG MID-LEVEL FGEN JUST AHEAD OF THE SYSTEM AS IT MOVES THROUGH
SOUTHWEST MICHIGAN TONIGHT. BOTTOM LINE... IT WOULD BE HARD TO
IMAGINE WE WILL NOT GET RAIN OVERNIGHT.

ONCE THE LOW PASSES US THE SIGNIFICANT RAINFALL WILL END. HOWEVER
THE SECONDARY COLD FRONT AND TRAILING NORTHERN STREAM WAVE WILL
BRING ANOTHER PERIOD OF SHOWERS TO THE AREA MIDDAY MONDAY INTO
EARLY EVENING. THAT BRINGS IN THE TRULY COLDER AIR.

MONDAY NIGHT WE MAY SEE A BREAK IN THE SHOWERS EARLY ON BUT THEN
THE WRAP AROUND MOISTURE MOVES IN AND WE SEE SHOWERS THAT MAY MIX
WITH AN CHANGE TO SNOW SHOWERS BY TUESDAY NIGHT. BY THE WAY THE
SPC SOUNDING CLIMATOLOGY PAGE SHOWS THE COLDEST 850 TEMPERATURE
FOR THE DTX SOUNDING TO BE -12C ON THE 22ND. THE ECWMF SHOWS -9.8C
AT 2 PM WEDNESDAY NEAR GRR. TO SAY THE LEAST...IT WILL GET COLDER
THIS COMING WEEK!

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

UNSEASONABLY COLD WEATHER IS ANTICIPATED WEDNESDAY AND THURSDAY WITH
DEEP CYCLONIC FLOW AND COLD AIR ADVECTION WITH THE UPPER LEVEL LOW
STILL IN PLACE OVER THE NORTHERN GREAT LAKES REGION. SCATTERED RAIN
SHOWERS WILL CONTINUE AND MAY BE MIXED AT TIMES WITH WET SNOW FLAKES
ESPECIALLY OVER RELATIVELY HIGHER ELEVATIONS OF OUR NORTHERN FCST
AREA.

TEMPERATURES SHOULD MODERATE SLIGHTLY FRIDAY THROUGH THE WEEKEND BUT
WILL STILL AVERAGE SEVERAL DEGREES BELOW NORMAL. THIS AS A SFC RIDGE
BUILDS IN AND AS THE UPPER LEVEL LOW MOVES MUCH FURTHER EAST TO THE
NEW ENGLAND REGION BY THEN. THE RIDGE WILL BRING FAIR AND SEASONABLY
COOL WEATHER FRIDAY THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 817 PM EDT SUN APR 19 2015

AVIATION CONDITIONS WILL CONTINUE TO DETERIORATE THIS EVENING WITH
MVFR AND IFR WEATHER DEVELOPING. BY MIDNIGHT OR A LITTLE BIT
AFTER...ALL SITES SHOULD HAVE IFR CEILINGS. THE STEADIER RAIN WILL
CONTINUE THROUGH ABOUT 100AM...THEN BECOME MORE SCATTERED
OVERNIGHT. THE LOW CEILINGS WILL PERSIST RIGHT INTO THE MORNING
HOURS OF MONDAY...WITH IFR AND LIFR CEILINGS PREVALENT INTO MID
MORNING. CONDITIONS SHOULD BEGIN TO IMPROVE MONDAY AFTERNOON AS
THE IFR CEILINGS TRY TO LIFT TO MVFR.

IT WILL BE BREEZY OUT OF THE EAST THIS EVENING AND THEN TURNING
WINDY MONDAY AFTERNOON FROM THE SOUTHWEST BEHIND A COLD FRONT.


&&

.MARINE...
ISSUED AT 258 PM EDT SUN APR 19 2015

I EXTENDED THE SCA THROUGH TUESDAY AFTERNOON FOR THE ALL THE ZONES
FROM WHITEHALL SOUTH ( NORTH OF THERE WINDS WILL NOT BE AS STRONG
OVERNIGHT). AFTER THE SURFACE LOW MOVES NORTH OF MUSKEGON WINDS WILL
INCREASE TO 30 KNOTS FROM THE SOUTHWEST THEN I EXPECT 15 TO 25
KNOT WINDS MONDAY INTO TUESDAY. AS THE COLD AIR COMES IN WAVES
WILL BUILD SO WE WILL LIKELY NEED A SCA FOR THE NORTHERN TWO ZONE
GROUPS MONDAY NIGHT AND TUESDAY.


&&

.HYDROLOGY...
ISSUED AT 1114 AM EDT SUN APR 19 2015

PERIODS OF RAIN ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON AND
AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. THE LIGHTER VARIETY OF
PRECIPITATION MAY EXTENT INTO MIDWEEK. THOUGH WE WILL SEE A DECENT SOIL
SOAKING IT SHOULD NOT BE SUBSTANTIAL ENOUGH TO CREATE FLOODING
CONCERNS. GRADUAL BUT MINOR RISES ARE LIKELY...SUSPECTING THAT
THIS WOULD STAY WITHIN BANKS FOR MOST LOCATIONS. I WOULD NOT RULE
OUT A COUPLE OF SITES FLIRTING WITH ADVISORY STAGE AS WE GO INTO
TUESDAY...ESPECIALLY IF ANY MODERATE RAINFALL IS MORE PERSISTENT
WITH THE FIRST COUPLE OF ROUNDS OF MOISTURE. OTHERWISE...AREA
RIVERS ARE WELL BEHAVED THROUGH THE PERIOD.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...DUKE
HYDROLOGY...JAM
MARINE...WDM







000
FXUS63 KGRR 200017
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
817 PM EDT SUN APR 19 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 258 PM EDT SUN APR 19 2015

A MAJOR CHANGE IN THE OVERALL WEATHER PATTERN IS ABOUT TO BEGIN. A
STRONG AND DEEPENING LOW PRESSURE SYSTEM WILL TRACK NORTHWARD
THROUGH WESTERN LOWER MICHIGAN TONIGHT BRINGING RAIN THAT MAY BE
HEAVY AT TIMES EARLY TONIGHT. AFTER THE SYSTEM MOVES NORTH OF THE
AREA LATER TONIGHT THE RAIN WILL DIMINISH TO SHOWERS BUT IT WILL
BE BREEZY. THEN SHOWERS AND BREEZY CONDITIONS WILL CONTINUE INTO
TUESDAY. BY TUESDAY NIGHT IT WILL GET COLD ENOUGH FOR SNOW TO MIX
WITH THE RAIN. THAT WILL CONTINUE INTO THURSDAY. IT WILL BE MUCH
COOLER THROUGH THIS ENTIRE PERIOD WITH HIGHS TUESDAY THROUGH
THURSDAY IN THE 40S AND LOWS NEAR FREEZING.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 258 PM EDT SUN APR 19 2015

THE PRIMARY ISSUE IS THE RAIN TONIGHT...THEN WINDY AND SHOWERS
MONDAY INTO TUESDAY. THERE IS A GOOD CHANCE OF MEASURABLE SNOW
OVER NORTHERN SECTIONS TUESDAY NIGHT.

THE DEEPENING STORM SYSTEM WILL TRACK THROUGH WESTERN LOWER
MICHIGAN TONIGHT BRINGING A PERIOD OF MODERATE TO HEAVY RAIN THAT
WILL LAST AROUND 6 HOURS IN ANY ONE PLACE. IT WILL BE BREEZY AT
FIRST BUT WINDS WILL DIMINISH TOWARD MIDNIGHT AS THE SURFACE LOW
MOVES THROUGH THE AREA.

THE RAIN EVENT TONIGHT REMAINS WELL SUPPORTED BY ALL THE MODELS.
THERE IS SOME ISSUE AS TO WHERE THE HEAVIEST RAIN WILL ACTUALLY
FALL BUT ALL AREAS GET AT LEAST A THIRD OF AN INCH AND MOST AREAS
SHOULD GET MORE THAN A HALF INCH OF RAIN TONIGHT. THIS IS ALL THE
RESULT OF UPPER WAVE THAT GOES NEGATIVE TILT OVER SOUTHWEST
MICHIGAN TONIGHT. THAT CAUSES THE SURFACE LOW TO TRACK NORTHWARD
AND DEEPEN RAPIDLY. ALSO THIS RESULTS IN A STRONG LOW LEVEL JET
(60 KNOTS)... STRONG 1000 TO 850 MOISTURE CONVERGENCE AIMED AT
SOUTHWEST LOWER MICHIGAN THIS EVENING AND CONDENSATION PRESSURE
DEFICITS NEAR ZERO MB THIS EVENING. THERE IS ALSO 40 KNOT OF WIND
PERPENDICULAR TO THE ISOTROPIC SURFACES EARLY TONIGHT... AND WE
CAN ALL ADD TO THAT PRECIPITATION WATER VALUES (1.4") NEAR 2
STANDARD DEVIATIONS FROM NORMAL AND MIXING RATIOS RISING TO NEAR 8
G/KG FROM UNDER 2 G/KG THIS MORNING. THERE IS ALSO A ZONE OF
STRONG MID-LEVEL FGEN JUST AHEAD OF THE SYSTEM AS IT MOVES THROUGH
SOUTHWEST MICHIGAN TONIGHT. BOTTOM LINE... IT WOULD BE HARD TO
IMAGINE WE WILL NOT GET RAIN OVERNIGHT.

ONCE THE LOW PASSES US THE SIGNIFICANT RAINFALL WILL END. HOWEVER
THE SECONDARY COLD FRONT AND TRAILING NORTHERN STREAM WAVE WILL
BRING ANOTHER PERIOD OF SHOWERS TO THE AREA MIDDAY MONDAY INTO
EARLY EVENING. THAT BRINGS IN THE TRULY COLDER AIR.

MONDAY NIGHT WE MAY SEE A BREAK IN THE SHOWERS EARLY ON BUT THEN
THE WRAP AROUND MOISTURE MOVES IN AND WE SEE SHOWERS THAT MAY MIX
WITH AN CHANGE TO SNOW SHOWERS BY TUESDAY NIGHT. BY THE WAY THE
SPC SOUNDING CLIMATOLOGY PAGE SHOWS THE COLDEST 850 TEMPERATURE
FOR THE DTX SOUNDING TO BE -12C ON THE 22ND. THE ECWMF SHOWS -9.8C
AT 2 PM WEDNESDAY NEAR GRR. TO SAY THE LEAST...IT WILL GET COLDER
THIS COMING WEEK!

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

UNSEASONABLY COLD WEATHER IS ANTICIPATED WEDNESDAY AND THURSDAY WITH
DEEP CYCLONIC FLOW AND COLD AIR ADVECTION WITH THE UPPER LEVEL LOW
STILL IN PLACE OVER THE NORTHERN GREAT LAKES REGION. SCATTERED RAIN
SHOWERS WILL CONTINUE AND MAY BE MIXED AT TIMES WITH WET SNOW FLAKES
ESPECIALLY OVER RELATIVELY HIGHER ELEVATIONS OF OUR NORTHERN FCST
AREA.

TEMPERATURES SHOULD MODERATE SLIGHTLY FRIDAY THROUGH THE WEEKEND BUT
WILL STILL AVERAGE SEVERAL DEGREES BELOW NORMAL. THIS AS A SFC RIDGE
BUILDS IN AND AS THE UPPER LEVEL LOW MOVES MUCH FURTHER EAST TO THE
NEW ENGLAND REGION BY THEN. THE RIDGE WILL BRING FAIR AND SEASONABLY
COOL WEATHER FRIDAY THROUGH SUNDAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 817 PM EDT SUN APR 19 2015

AVIATION CONDITIONS WILL CONTINUE TO DETERIORATE THIS EVENING WITH
MVFR AND IFR WEATHER DEVELOPING. BY MIDNIGHT OR A LITTLE BIT
AFTER...ALL SITES SHOULD HAVE IFR CEILINGS. THE STEADIER RAIN WILL
CONTINUE THROUGH ABOUT 100AM...THEN BECOME MORE SCATTERED
OVERNIGHT. THE LOW CEILINGS WILL PERSIST RIGHT INTO THE MORNING
HOURS OF MONDAY...WITH IFR AND LIFR CEILINGS PREVALENT INTO MID
MORNING. CONDITIONS SHOULD BEGIN TO IMPROVE MONDAY AFTERNOON AS
THE IFR CEILINGS TRY TO LIFT TO MVFR.

IT WILL BE BREEZY OUT OF THE EAST THIS EVENING AND THEN TURNING
WINDY MONDAY AFTERNOON FROM THE SOUTHWEST BEHIND A COLD FRONT.


&&

.MARINE...
ISSUED AT 258 PM EDT SUN APR 19 2015

I EXTENDED THE SCA THROUGH TUESDAY AFTERNOON FOR THE ALL THE ZONES
FROM WHITEHALL SOUTH ( NORTH OF THERE WINDS WILL NOT BE AS STRONG
OVERNIGHT). AFTER THE SURFACE LOW MOVES NORTH OF MUSKEGON WINDS WILL
INCREASE TO 30 KNOTS FROM THE SOUTHWEST THEN I EXPECT 15 TO 25
KNOT WINDS MONDAY INTO TUESDAY. AS THE COLD AIR COMES IN WAVES
WILL BUILD SO WE WILL LIKELY NEED A SCA FOR THE NORTHERN TWO ZONE
GROUPS MONDAY NIGHT AND TUESDAY.


&&

.HYDROLOGY...
ISSUED AT 1114 AM EDT SUN APR 19 2015

PERIODS OF RAIN ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON AND
AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. THE LIGHTER VARIETY OF
PRECIPITATION MAY EXTENT INTO MIDWEEK. THOUGH WE WILL SEE A DECENT SOIL
SOAKING IT SHOULD NOT BE SUBSTANTIAL ENOUGH TO CREATE FLOODING
CONCERNS. GRADUAL BUT MINOR RISES ARE LIKELY...SUSPECTING THAT
THIS WOULD STAY WITHIN BANKS FOR MOST LOCATIONS. I WOULD NOT RULE
OUT A COUPLE OF SITES FLIRTING WITH ADVISORY STAGE AS WE GO INTO
TUESDAY...ESPECIALLY IF ANY MODERATE RAINFALL IS MORE PERSISTENT
WITH THE FIRST COUPLE OF ROUNDS OF MOISTURE. OTHERWISE...AREA
RIVERS ARE WELL BEHAVED THROUGH THE PERIOD.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...DUKE
HYDROLOGY...JAM
MARINE...WDM







000
FXUS63 KMQT 192352
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
752 PM EDT SUN APR 19 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

TWO UPPER LEVEL WAVES WILL BE AFFECTING THE REGION TONIGHT BEFORE
MERGING TOGETHER INTO A LARGE UPPER TROUGH THAT WILL PERSIST OVER
EASTERN CANADA AND THE GREAT LAKES REGION FOR MUCH OF THE UPCOMING
WORK WEEK. THIS WILL LEAD TO A TRANSITION FROM THE ABOVE NORMAL
TEMPERATURES AND DRY CONDITIONS TO A PERIOD OF BELOW NORMAL
TEMPERATURES AND PERIODS OF RAIN/SNOW SHOWERS.

THE FIRST WAVE OF PRECIPITATION JUST BRUSHED THE WESTERN U.P.
EARLIER TODAY...ASSOCIATED WITH A SHORTWAVE AND MID LEVEL WARM AIR
ADVECTION. MUCH OF THAT PRECIPITATION HAS SHIFTED OFF TO THE NORTH
OF THE MINNESOTA ARROWHEAD...BUT LINGERING MID LEVEL MOISTURE AND
BROAD BUT WEAK WARM AIR ADVECTION HAS PRODUCED A FEW RAIN SHOWERS
OVER WESTERN/CENTRAL UPPER MICHIGAN LATE THIS MORNING AND THROUGH
THE EARLY AFTERNOON. WHILE THE 12Z KGRB SOUNDING STILL SHOWS SOME
DRY AIR BELOW THE CLOUD BASES...IT HAS ERODED SIGNIFICANTLY SINCE
THE 00Z KGRB SOUNDING AND ALLOWED SOME OF THAT RAIN TO REACH THE
GROUND. THAT DISTURBANCE PRODUCING THE SHOWERS WILL SHIFT TO THE
NORTH OVER THE NEXT COUPLE OF HOURS AND SHIFT THE FOCUS TO THE RAIN
CURRENTLY TO THE WEST AND SOUTH OF THE CWA.

WITH THE LATEST TRENDS IN THE MODELS DELAYING THE ARRIVAL OF THE
PRECIPITATION FROM THE SOUTH (ASSOCIATED WITH THE SOUTHERN WAVE AND
SURFACE LOW QUICKLY LIFTING NORTH ACROSS THE SOO MONDAY MORNING)
UNTIL LATE IN THE EVENING AND MORE DURING THE OVERNIGHT HOURS...HAVE
CONTINUED TO SHOW THAT SLOWING TREND IN THE POPS FOR THIS EVENING.
IN FACT...OTHER THAN SOME CHANCES OVER THE FAR WEST THIS
EVENING...HAVE REMOVED THE POPS OVER THE CENTRAL EAST BETWEEN THE
23Z-03Z PERIOD AND THEN RAMPED THEM UP AS THAT WAVE AND LOW ARRIVES
FROM THE SOUTH. THAT PRECIPITATION WILL THEN QUICKLY SHIFT NORTH
ACROSS THE AREA AND EXPECT MUCH OF THE CENTRAL/EASTERN U.P. TO SEE
AT LEAST 0.3 INCH OF RAIN. THERE WILL BE SOME HIGHER
AMOUNTS...LIKELY 0.5-0.6IN WHERE THE DEFORMATION ZONE OCCURS ON THE
NORTHWEST SIDE OF THE SURFACE LOW (SOMEWHERE AROUND THE CENTRAL OR
WEST-CENTRAL U.P.). FARTHER TO THE WEST...EXPECT THE ONGOING RAIN
SHOWERS STRETCHING FROM THE ARROWHEAD OF MINNESOTA THROUGH WESTERN
WISCONSIN AND INTO NORTHEAST IOWA TO SLOWLY SHIFT EAST INTO FAR
WESTERN UPPER MICHIGAN THIS EVENING...AS THE 850-700MB TROUGH SLOWLY
WORKS ITS WAY TO THE EAST. THIS PRECIPITATION WILL MERGE WITH THE
WAVE COMING UP FROM THE SOUTH AND FILL IN THE EXPECTED GAP OVER THE
KEWEENAW OVERNIGHT.

WITH THE SHORTWAVE AND SURFACE LOW QUICKLY MOVING TO THE NORTH ON
MONDAY...EXPECT THE PRECIPITATION TO DIMINISH FROM SOUTHWEST TO
NORTHEAST THROUGH THE DAY (AIDED BY THE MID LEVEL DRY SLOT THAT
SLOWLY MOVES INTO THE AREA). WHILE MUCH OF THIS PRECIP WILL OCCUR AS
RAIN...THE COLD AIR GRADUALLY MOVING INTO THE WESTERN CWA LATE
TONIGHT AND MONDAY COULD CAUSE IT TO MIXING WITH OR EVEN CHANGING
OVER TO SNOW OVER THE WEST AND POSSIBLY EVEN NORTH CENTRAL. THOUGHT
THAT THE WETBULB ZERO HAD A GOOD HANDLE ON THE WEST TO EAST
TRANSITION OF THAT MIX WITH SNOW...BUT DO HAVE A CONCERN ON THE
AMOUNT OF ICE CRYSTALS THAT WILL BE PRESENT ON MONDAY. MODELS
SHOWING THAT THE DEEPER MOISTURE REALLY BEGINS TO PULL OUT THROUGH
THE DAY AS THE MID LEVEL DRY SLOT MOVES BEHIND THE 850/700MB TROUGH.
THAT CONCERN WARRANTS KEEPING RAIN POTENTIAL IN THE FORECAST EVEN
THOUGH SOME AREAS THE WETBULB ZERO VALUES WOULD SUPPORT ALL SNOW.
ONE FINAL NOTE...THE HIGHER RESOLUTION 12Z MODELS ARE SHOWING A
SLOWER DEPARTURE TO THE PRECIP ON MONDAY...SO DID TREND SLIGHTLY
SLOWER WITH THIS FORECAST AND IT MAY NEED TO BE DELAYED FURTHER WITH
THE UPCOMING SHIFT. THAT SLOWER DEPARTURE AND INDICATIONS OF COLDER
AIR...COULD LEAD TO SOME MINOR SNOW ACCUMULATIONS ON GRASSY SURFACES
OVER THE WEST AROUND MID MORNING.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 423 PM EDT SUN APR 19 2015

THE PATTERN WILL BE DOMINATED BY A MID/UPPER LEVEL LOW MOVING SLOWLY
THROUGH THE GREAT LAKES BRINGING UNSETTLED WEATHER ALONG WITH BELOW
NORMAL TEMPERATURES. THE LOW SHOULD FINALLY SHIFT TOWARD ERN CANADA
AND NEW ENGLAND BY THE WEEKEND LEAVING NW FLOW IN PLACE WITH
CONTINUED BELOW NORMAL TEMPERATURES.

MON NIGHT THROUGH TUE NIGHT...MODELS SUGGEST THAT THE MID LEVEL LOW
WILL SLOWLY WOBBLE INTO THE NRN GREAT LAKES. WITH THE COMBINATION OF
DEEP MOISTURE AND WEAK SHORTWAVES NEAR THE LOW...EXPECT INCREASING
PCPN CHANCES AS MAINLY SNOW...PER FCST SOUNDINGS. THERE MAY BE SOME
ADDITIONAL LAKE ENHANCED (850 MB TEMPS DROP TO AROUND -8C) INTO THE
HIGHER TERRAIN OVER THE WEST WITH UPSLOPE WNW FLOW. SNOW
ACCUMULATIONS OF A FEW INCHES ARE POSSIBLE...MAINLY ON GRASSY
SURFACES. HOWEVER...WITH THE ARRIVAL OF THE SNOW OVERNIGHT SOME
ACCUMULATION ON ROADS MAY ALSO CREATE HAZARDOUS TRAVEL TUE MORNING.
DAYTIME HEATING TUE MAY ENHANCE THE PCPN OVER INLAND AREAS WITH STEEP
SFC-700MB LAPSE RATES DEVELOPING. WITH TEMPS CLIMBING TO AROUND
40F...THE PCPN MAY MIX WITH RAIN OVER THE SE HALF OF THE CWA. 12Z NAM
FCST WET-BULB ZERO HEIGHTS WERE USED TO DELINEATE PCPN TYPE. ANOTHER
INCH OR TWO OF SNOW WILL BE POSSIBLE MAINLY OVER THE NW WIND
SNOWBELTS IN THE WEST TUE NIGHT AS 850 MB TEMPS DROP TO AROUND -12C
WHILE THE DEEP MOISTURE AND LOW LEVEL CYCLONIC FLOW REMAIN IN PLACE.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN SOUTH DURING
PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE CONTRIBUTION AS 850
MB TEMPS RANGE FROM -10C TO -13C...THE BEST COVERAGE DURING THE
DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM LAKE SUPERIOR WHERE
HEATING WILL BE STRONGEST. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW
NORMAL...IN THE MID 30S TO LOWER 40S...WARMEST S CNTRL.

FRI-SUN...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH ONLY MINIMAL PCPN CHANCES.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 752 PM EDT SUN APR 19 2015

LOW PRES ORGANIZING OVER INDIANA WILL LIFT N TONIGHT WHILE A LOW
PRES TROF MOVES E INTO UPPER MI. THESE 2 FEATURES WILL SPREAD SHRA
ACROSS THE AREA AND BRING DETERIORATING CONDITIONS.

SFC TROF WILL PASS KIWD THIS EVENING...BRINGING A WIND SHIFT TO THE
NW OFF LAKE SUPERIOR. WITH RAIN OVER THE COLD LAKE WATERS AND AN
UPSLOPE WIND...EXPECT CONDITIONS TO FALL TO MVFR BY MID EVENING AND
TO LIFR BY 06Z. THE RAIN WILL MIX WITH OR CHANGE TO SNOW MON
MORNING. PCPN WILL THEN DIMINISH IN THE AFTN WITH CONDITIONS
IMPROVING TO MVFR UNDER GUSTY WNW WINDS.

AT KCMX...WITH MAIN AREA OF PCPN AND SFC TROF NOT ARRIVING UNTIL
EARLY MON MORNING...VFR CONDITIONS SHOULD PREVAIL UNTIL LATE
TONIGHT. EXPECT A QUICK DROP TO LIFR MON MORNING UNDER UPSLOPE NW
WIND...THEN ONLY GRADUAL IMPROVEMENT TO IFR IN THE AFTN AS -SHRA
CONTINUE. NW WIND WILL LIKELY GUST TO 30KT OR MORE IN THE AFTN.

AT KSAW...VFR CONDITIONS WILL PREVAIL THIS EVENING. ARRIVAL OF SHRA
OVERNIGHT AND WINDS BACKING AROUND TO AN UPSLOPE NE TO N DIRECTION
OFF LAKE SUPERIOR WILL RESULT IN CONDITIONS FALLING TO LIFR BEFORE
12Z. AS WINDS BACK TO THE NW AND THEN W IN THE AFTN AND PCPN
DIMINISHES...EXPECT IMPROVEMENT TO MVFR.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 258 PM EDT SUN APR 19 2015

SOUTHEASTERLY WINDS UP TO 25-30KTS ARE OCCURRING OVER NORTHEAST
LAKE SUPERIOR...WITH A FEW GUSTS NEARING GALE FORCE VALUES AT THE
HIGHER PLATFORMS (SHIP OBS AND PILM4). AS A LOW IN SOUTHERN ILLINOIS
LIFTS NORTH TONIGHT AND THROUGH THE SOO ON MONDAY MORNING...WINDS
WILL WEAKEN THIS EVENING AND THEN BACK TO THE WEST-NORTHWEST ON
MONDAY. WITH THE LOW BECOMING STATIONARY JUST TO THE SOUTHWEST OF
JAMES BAY MONDAY NIGHT THROUGH WEDNESDAY...PERSISTENT NORTHWESTERLY
WINDS OF 20-30KTS ARE EXPECTED. ALTHOUGH THE LOW WILL WEAKEN AND
MOVE EAST ACROSS QUEBEC WEDNESDAY NIGHT INTO THURSDAY...THE
NORTHWEST WINDS UP TO 25KTS WILL PERSIST AS A RIDGE MOVES INTO THE
NORTHERN PLAINS.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...SRF
LONG TERM...JLB
AVIATION...ROLFSON
MARINE...SRF



000
FXUS63 KAPX 192337
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
737 PM EDT SUN APR 19 2015

.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 402 PM EDT SUN APR 19 2015

HIGH IMPACT WEATHER: MINIMAL

FORECAST CHALLENGE: TIMING OF THE RAIN TONIGHT.

OVERVIEW...WHILE THE MOISTURE HAS BEEN INCREASING ALONG THE LAKE
HURON SHORE AND INLAND OF NE LOWER, NW LOWER HAS BEEN DRYING OUT
WITH A GOOD PORTION OF THE AREA WEST OF I-75 HAVING FALLEN BELOW
25%. IN E UPPER, THE RH HAS BEEN BETWEEN 40% AND 45%. WHAT THIS IS
DOING IS DELAYING THE RAIN SHIELD`S TRAVEL NORTH, WHICH HAD JUST
MADE IT TO THE MICHIGAN/INDIANA BORDER AROUND 19Z. USING THE TIMING
TOOL ON AWIPS, IT LOOKS LIKE THE RAIN SHOULD GET TO THE M-55
CORRIDOR AROUND 23Z, M-72 AROUND 00Z, M-32 AROUND 01Z, AND THE
STRAIT BETWEEN 02Z AND 03Z.

DETAILS FOR TONIGHT...AS WAS MENTIONED, TRYING TO TIME THIS SYSTEM
WITH THE DRY AIR IN THE LOWER LEVELS IS MADDENING. THE QUESTION
ISN`T IF THE AIR WILL LEAVE, BUT WHEN AS THE SFC LOW WILL, AS IT
MOVES UP FROM THE MID-MISSISSIPPI VALLEY, OVERWHELM WITH DRY AIR
WITH ITS MOISTURE, AND ALLOW THE RAIN TO FALL ALL THE WAY TO THE
SFC. HOWEVER, ONCE THE RAIN STARTS, IT WILL FALL THROUGH THE NIGHT
AS THE SFC NORTH OVER THE WESTERN PART OF THE STATE BETWEEN 06Z AND
12Z. THIS SFC LOW AND ASSOCIATED 500 MB SHORTWAVE TROUGH AND 50 KNOT
SPEED MAX THAT MOVES OVER THE STATE, OVER THE WARM FRONT. WITH THE
PWAT AROUND 1.0" OVERNIGHT OVER THE FORECAST AREA, WILL EXPECT
THAT A DECENT STEADY RAIN WILL RESULT.

&&

.SHORT TERM...(MONDAY THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

...SHOWERY/COOL/UNSETTLED THROUGH MIDWEEK...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: WELL-DEFINED SPLIT FLOW PATTERN FROM THE
END OF LAST WEEK NOW CONSOLIDATING AS NORTHERN BRANCH SHORT WAVE
TROUGH DIGS SOUTHEAST FROM WESTERN CANADA AND SCOOPS UP PESKY
SOUTHERN BRANCH VORTEX THAT HAS BEEN SPINNING ACROSS THE GREAT
BASIN/SOUTHERN ROCKIES SINCE THE MIDDLE OF LAST WEEK.  POSITIVE
PACIFIC TELECONNECTIONS LEADING TO A MORE AMPLIFIED PATTERN (BIG
TROUGH EAST OF THE DATELINE WITH +PNA RIDGING ALONG THE WEST COAST
OF NORTH AMERICA.  THIS CONSOLIDATING CENTRAL NORTH AMERICAN TROUGH
WILL BECOME THE PREDOMINANT WEATHER FEATURE THIS WEEK AS IT TAKES UP
RESIDENCE WITH REX BLOCKING ALONG THE WEST COAST...WITH AN UPPER LOW
EVENTUALLY PARKING ITSELF OVER THE GREAT LAKES BY MIDWEEK.

SOUTHERN BRANCH DISTURBANCE LOOKS TO COME OUT IN TWO PIECES
MONDAY...WHILE CLOSED CIRCULATION ALOFT DEVELOPS OVER NORTHWEST
ONTARIO/UPPER MIDWEST.  UPPER LOW THEN SETTLES OVER LAKE SUPERIOR
TUESDAY AND HANGS IN THROUGH MIDWEEK.  AT THE SURFACE...LEAD
SOUTHERN BRANCH SHORT WAVE TROUGH HAS AN ASSOCIATED SURFACE LOW OVER
THE MID MISSISSIPPI VALLEY THAT IS FORECAST TO DEEPEN AND LIFT NORTH
INTO LOWER MICHIGAN BY MONDAY MORNING...PROBABLY BELOW 990MB WHICH
IS PRETTY SIGNIFICANT BY MID-APRIL STANDARDS.  THIS LOW WILL PULL
COOLER AIR INTO MICHIGAN STARTING MONDAY NIGHT...CYCLONIC FLOW
LINGERS INTO MIDWEEK.

PRIMARY FORECAST CONCERNS: VARYING PRECIPITATION CHANCES THROUGH
MIDWEEK...AS WELL AS PRECIPITATION TYPE.

MONDAY...12Z SOUNDINGS AND GOES SOUNDER IMAGERY SHOWS A NICE SURGE
OF MOISTURE COMING UP ACROSS THE SOUTHEASTERN STATES (1.00-1.50 INCH
PRECIPITABLE WATER) WHICH IS PUSHING A LARGE ARE OF RAIN NORTHWARD
ACROSS THE OHIO VALLEY...AND EVENTUALLY INTO MICHIGAN TONIGHT/MONDAY
MORNING.  THIS WILL PUSH THROUGH THE FORECAST AREA MONDAY MORNING
(PERHAPS FAIRLY QUICKLY) WITH MID LEVEL DRYING (POSSIBLY TAPERING
OFF TO A PERIOD OF DRIZZLE).  SURFACE LOW TRACKS ACROSS NORTHERN
LOWER MONDAY MORNING...BEHIND THAT A LINGERING BAND OF DEFORMATION/
FRONTOGENETIC PRECIPITATION WILL ROTATE IN FROM THE WEST DURING THE
AFTERNOON HOURS.  IN ADDITION...COULD SEE SOME CONVECTIVE PRECIP
CLOSE TO THE SOUTHEAST PORTION OF THE FORECAST AREA DURING THE LATE
MORNING/AFTERNOON WITH SOME ELEVATED INSTABILITY (TQ INDICES
POTENTIALLY IN THE 16-20C RANGE NEAR LOW LEVEL THETA-E RIDGE) AND
SECOND PIECE OF SOUTHERN BRANCH ENERGY SWINGING NORTHEAST ACROSS THE
LOWER PENINSULA.  MORE LIKELY THIS ACTIVITY WOULD OCCUR ACROSS THE
THUMB INTO LAKE HURON...BUT MAY BE CLOSE.  WILL NOT TRY AND VARY
PRECIP PROBABILITIES IN THE FORECAST GRIDS TO ACCOUNT FOR TIMING OF
VARIOUS WAVES OF PRECIPITATION (AS IT WILL BE WRONG ANYHOW)...WITH A
GENERIC HIGH LIKELY/CATEGORICAL POP THROUGH THE DAY SUFFICIENT FOR
NOW. AS LONG AS INITIAL AREA OF RAIN SCOOTS NORTH QUICKLY MONDAY
MORNING... NOT EXPECT A LOT OF RAINFALL IN THE 12Z-00Z TIME FRAME
(UNLESS CONVECTION CAN CLIP FAR EASTERN ZONES DURING THE AFTERNOON)
WITH FORECAST 12H QPF UNDER 0.25 INCH THOUGH COULD BE HIGHER ACROSS
EASTERN UPPER/FAR NORTHEAST LOWER GIVEN THE ABOVE CAVEATS.  TRACK OF
THE LOW RIGHT ACROSS LOWER MICHIGAN WILL LEAD TO SOME TRICKY
TEMPERATURE FORECASTS...IN GENERAL COOLER WEST AND WARMER EAST WITH
FALLING TEMPERATURES DURING THE MID/LATE AFTERNOON AS WINDS SWITCH
AROUND TO A MORE WESTERLY COMPONENT.

WHAT REMAINS OF DEFORMATION PRECIP BAND EXPECTED TO LIFT NORTHEAST
ACROSS NORTHERN MICHIGAN MONDAY EVENING...AFTER THAT MAY BE ON THE
QUIET SIDE OVERNIGHT AND WILL CONFINE POPS TO THE EVENING HOURS.
PRECIP TYPE MAY BE IN QUESTION ACROSS EASTERN UPPER AS DEPTH OF
SURFACE BASED WARM LAYER SHRINKS.  AS NORTHERN BRANCH SHORT WAVE
TROUGHS START GETTING INVOLVED IN THE FORECAST SCENARIO CAN`T RULE
OUT SOME ADDITIONAL SHOWERS DEVELOPING OVERNIGHT INTO TUESDAY
MORNING BUT NOT CONVINCED THE PROBABILITY RISES TO A SUFFICIENT
LEVEL TO INCLUDE IN THE FORECAST...WILL LEAVE IT OUT AND MAINTAIN
CONTINUITY.

TUESDAY...DEEP LAYER CYCLONIC FLOW ACROSS THE UPPER LAKES SPELLS
UNSETTLED AND NOT WARM WEATHER FOR TUESDAY.  DEEP MOISTURE WILL
ROTATE AROUND THE SOUTH SIDE OF THE UPPER LOW...AND COOL
TEMPERATURES ALOFT (AT OR BELOW -30C/500MB) WILL ADD A DIURNAL
COMPONENT TO SUPPORT SHOWERS...AND GIVEN COOL TEMPERATURES PRECIP
COULD FALL AS RAIN/SNOW/GRAUPEL.  GUSTY SOUTHWEST WINDS (20-30MPH
GUSTS PROBABLE NORTHERN LOWER) WON`T MAKE IT FEEL ANY WARMER...WITH
AFTERNOON HIGHS AROUND 40-MID 40S (10-15 DEGREES BELOW NORMAL).
SHOWERS WILL CONTINUE INTO TUESDAY NIGHT...COVERAGE MAY DECREASE
WITH ON DOWNWARD SIDE OF DIURNAL HEATING CYCLE BUT THEY WILL STILL
BE AROUND.  COOLING TEMPERATURES ALSO WILL TREND PRECIPITATION TO
ALL SNOW SHOWERS TUESDAY EVENING.

WEDNESDAY...MORE OF THE SAME FOR WEDNESDAY WITH CONTINUED COOL
CYCLONIC FLOW AND VARIOUS DISTURBANCES ROTATING AROUND THE PARENT
VORTEX.  HIGH TEMPERATURES PROBABLY A FEW DEGREES COOLER WEDNESDAY
AFTERNOON...WITH MORE TEMPERATURES STUCK BELOW 40 DEGREES LIKELY.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

THE PERIOD PICKS UP JUST AS THE PREVIOUS LEFT OFF WITH UPPER LEVEL
TROUGHING OVERHEAD AND MULTIPLE WEAK WAVES ROTATING THROUGH THE BASE
OF THE TROUGH...BRINGING RAIN/SNOW SHOWER CHANCES WEDNESDAY NIGHT
AND INTO THE DAY THURSDAY. AS MENTIONED BY PRIOR SHIFT...THE
MOVEMENT OF THE OVERALL PATTERN LOOKS MINIMAL THROUGH THE WEEKEND
WITH TROUGHING CLOSE ENOUGH WHERE ANY SUBTLE WAVE COULD KICK OFF
ADDITIONAL SHOWER ACTIVITY. HAVE GONE AHEAD AND ADDED LOW END CHANCE
POPS FOR THURSDAY NIGHT (MAINLY DIRECTLY DOWNWIND OF LAKE MICHIGAN
AND FOR THE EASTERN U.P.)...BUT WILL KEEP A MAINLY DRY FORECAST FROM
FRIDAY THROUGH SUNDAY AS THE MAJORITY OF THE TIME LOOKS TO REMAIN
PRECIPITATION FREE.

NO DOUBT THE OVERALL PATTERN WILL BE A RATHER CHILLY ONE...WITH H8
TEMPS APPROACHING -8C THROUGHOUT THE PERIOD. A BLENDED MODEL
GUIDANCE APPROACH WOULD SUGGEST HIGH TEMPERATURES STUCK IN THE UPPER
30S AND 40S (A SOLID 10-15 DEGREES BELOW NORMAL) AND LOWS MAINLY IN
THE 20S TO LOWER 30S.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 737 PM EDT SUN APR 19 2015

CONDITIONS DETERIORATING TO IFR TONIGHT. SOME IMPROVEMENT MONDAY.

LOW PRESSURE IN W CENTRAL INDIANA WILL LIFT NORTH...CROSSING
NORTHERN LOWER MI MONDAY MORNING. RAIN SHIELD IS SLOWLY ADVANCING
NORTH INTO CENTRAL LOWER MI...WITH SOME SHRA DEVELOPING OUT AHEAD.
RAIN WILL STEADILY ADVANCE INTO THE REGION TONIGHT...RESULTING IN
LOWERING CIGS/VSBYS WITH TIMES. ALL SITES SHOULD SEE IFR CIGS FOR
A PERIOD LATE TONIGHT INTO MONDAY MORNING. IMPROVING TO MVFR
DURING THE DAY MONDAY...THOUGH WITH SOME -SHRA LINGERING.

GUSTY EAST WINDS WILL LIGHTEN UP OVERNIGHT...WITH SOMEWHAT
BLUSTERY WEST WINDS DEVELOPING BY MONDAY AFTERNOON.

&&

.MARINE...
ISSUED AT 402 PM EDT SUN APR 19 2015

TONIGHT THROUGH TUESDAY...EAST WINDS AHEAD OF THE SFC LOW WILL
CONTINUE TO INCREASE ACROSS THE UPPER GREAT LAKES AS THE PRESSURE
GRADIENT TIGHTENS UP ESPECIALLY OVER LAKE HURON AND E UPPER. THE SFC
LOW MOVES OVER N LAKE MICHIGAN AND IT LOOKS LIKE THE GRADIENT SHOULD
JUST BE SLACK ENOUGH FOR THE WINDS TO REMAIN BELOW MOST OF THE SMALL
CRAFT CRITERIA IN THE NEARSHORE WATERS. ONCE THE SFC LOW MOVES NORTH
OF THE UPPER MICHIGAN, THE PRESSURE GRADIENT WILL TIGHTEN BRIEFLY
OVER THE UPPER GREAT LAKES BRINGING SMALL CRAFT CRITERIA TO MOST, IF
NOT ALL OF THE NEARSHORES MONDAY AFTERNOON AND MONDAY NIGHT.
TUESDAY, AS THE SFC LOW STALLS NORTH OF LAKE SUPERIOR, THE WINDS
WILL INCREASE AS THE GRADIENT AGAIN TIGHTENS, AND THEN RELAXES BY
THE AFTERNOON.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LSZ321-322.

&&

$$

NEAR TERM...JSL
SHORT TERM...JPB
LONG TERM...GILLEN
AVIATION...JAZ
MARINE...JSL




000
FXUS63 KAPX 192337
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
737 PM EDT SUN APR 19 2015

.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 402 PM EDT SUN APR 19 2015

HIGH IMPACT WEATHER: MINIMAL

FORECAST CHALLENGE: TIMING OF THE RAIN TONIGHT.

OVERVIEW...WHILE THE MOISTURE HAS BEEN INCREASING ALONG THE LAKE
HURON SHORE AND INLAND OF NE LOWER, NW LOWER HAS BEEN DRYING OUT
WITH A GOOD PORTION OF THE AREA WEST OF I-75 HAVING FALLEN BELOW
25%. IN E UPPER, THE RH HAS BEEN BETWEEN 40% AND 45%. WHAT THIS IS
DOING IS DELAYING THE RAIN SHIELD`S TRAVEL NORTH, WHICH HAD JUST
MADE IT TO THE MICHIGAN/INDIANA BORDER AROUND 19Z. USING THE TIMING
TOOL ON AWIPS, IT LOOKS LIKE THE RAIN SHOULD GET TO THE M-55
CORRIDOR AROUND 23Z, M-72 AROUND 00Z, M-32 AROUND 01Z, AND THE
STRAIT BETWEEN 02Z AND 03Z.

DETAILS FOR TONIGHT...AS WAS MENTIONED, TRYING TO TIME THIS SYSTEM
WITH THE DRY AIR IN THE LOWER LEVELS IS MADDENING. THE QUESTION
ISN`T IF THE AIR WILL LEAVE, BUT WHEN AS THE SFC LOW WILL, AS IT
MOVES UP FROM THE MID-MISSISSIPPI VALLEY, OVERWHELM WITH DRY AIR
WITH ITS MOISTURE, AND ALLOW THE RAIN TO FALL ALL THE WAY TO THE
SFC. HOWEVER, ONCE THE RAIN STARTS, IT WILL FALL THROUGH THE NIGHT
AS THE SFC NORTH OVER THE WESTERN PART OF THE STATE BETWEEN 06Z AND
12Z. THIS SFC LOW AND ASSOCIATED 500 MB SHORTWAVE TROUGH AND 50 KNOT
SPEED MAX THAT MOVES OVER THE STATE, OVER THE WARM FRONT. WITH THE
PWAT AROUND 1.0" OVERNIGHT OVER THE FORECAST AREA, WILL EXPECT
THAT A DECENT STEADY RAIN WILL RESULT.

&&

.SHORT TERM...(MONDAY THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

...SHOWERY/COOL/UNSETTLED THROUGH MIDWEEK...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: WELL-DEFINED SPLIT FLOW PATTERN FROM THE
END OF LAST WEEK NOW CONSOLIDATING AS NORTHERN BRANCH SHORT WAVE
TROUGH DIGS SOUTHEAST FROM WESTERN CANADA AND SCOOPS UP PESKY
SOUTHERN BRANCH VORTEX THAT HAS BEEN SPINNING ACROSS THE GREAT
BASIN/SOUTHERN ROCKIES SINCE THE MIDDLE OF LAST WEEK.  POSITIVE
PACIFIC TELECONNECTIONS LEADING TO A MORE AMPLIFIED PATTERN (BIG
TROUGH EAST OF THE DATELINE WITH +PNA RIDGING ALONG THE WEST COAST
OF NORTH AMERICA.  THIS CONSOLIDATING CENTRAL NORTH AMERICAN TROUGH
WILL BECOME THE PREDOMINANT WEATHER FEATURE THIS WEEK AS IT TAKES UP
RESIDENCE WITH REX BLOCKING ALONG THE WEST COAST...WITH AN UPPER LOW
EVENTUALLY PARKING ITSELF OVER THE GREAT LAKES BY MIDWEEK.

SOUTHERN BRANCH DISTURBANCE LOOKS TO COME OUT IN TWO PIECES
MONDAY...WHILE CLOSED CIRCULATION ALOFT DEVELOPS OVER NORTHWEST
ONTARIO/UPPER MIDWEST.  UPPER LOW THEN SETTLES OVER LAKE SUPERIOR
TUESDAY AND HANGS IN THROUGH MIDWEEK.  AT THE SURFACE...LEAD
SOUTHERN BRANCH SHORT WAVE TROUGH HAS AN ASSOCIATED SURFACE LOW OVER
THE MID MISSISSIPPI VALLEY THAT IS FORECAST TO DEEPEN AND LIFT NORTH
INTO LOWER MICHIGAN BY MONDAY MORNING...PROBABLY BELOW 990MB WHICH
IS PRETTY SIGNIFICANT BY MID-APRIL STANDARDS.  THIS LOW WILL PULL
COOLER AIR INTO MICHIGAN STARTING MONDAY NIGHT...CYCLONIC FLOW
LINGERS INTO MIDWEEK.

PRIMARY FORECAST CONCERNS: VARYING PRECIPITATION CHANCES THROUGH
MIDWEEK...AS WELL AS PRECIPITATION TYPE.

MONDAY...12Z SOUNDINGS AND GOES SOUNDER IMAGERY SHOWS A NICE SURGE
OF MOISTURE COMING UP ACROSS THE SOUTHEASTERN STATES (1.00-1.50 INCH
PRECIPITABLE WATER) WHICH IS PUSHING A LARGE ARE OF RAIN NORTHWARD
ACROSS THE OHIO VALLEY...AND EVENTUALLY INTO MICHIGAN TONIGHT/MONDAY
MORNING.  THIS WILL PUSH THROUGH THE FORECAST AREA MONDAY MORNING
(PERHAPS FAIRLY QUICKLY) WITH MID LEVEL DRYING (POSSIBLY TAPERING
OFF TO A PERIOD OF DRIZZLE).  SURFACE LOW TRACKS ACROSS NORTHERN
LOWER MONDAY MORNING...BEHIND THAT A LINGERING BAND OF DEFORMATION/
FRONTOGENETIC PRECIPITATION WILL ROTATE IN FROM THE WEST DURING THE
AFTERNOON HOURS.  IN ADDITION...COULD SEE SOME CONVECTIVE PRECIP
CLOSE TO THE SOUTHEAST PORTION OF THE FORECAST AREA DURING THE LATE
MORNING/AFTERNOON WITH SOME ELEVATED INSTABILITY (TQ INDICES
POTENTIALLY IN THE 16-20C RANGE NEAR LOW LEVEL THETA-E RIDGE) AND
SECOND PIECE OF SOUTHERN BRANCH ENERGY SWINGING NORTHEAST ACROSS THE
LOWER PENINSULA.  MORE LIKELY THIS ACTIVITY WOULD OCCUR ACROSS THE
THUMB INTO LAKE HURON...BUT MAY BE CLOSE.  WILL NOT TRY AND VARY
PRECIP PROBABILITIES IN THE FORECAST GRIDS TO ACCOUNT FOR TIMING OF
VARIOUS WAVES OF PRECIPITATION (AS IT WILL BE WRONG ANYHOW)...WITH A
GENERIC HIGH LIKELY/CATEGORICAL POP THROUGH THE DAY SUFFICIENT FOR
NOW. AS LONG AS INITIAL AREA OF RAIN SCOOTS NORTH QUICKLY MONDAY
MORNING... NOT EXPECT A LOT OF RAINFALL IN THE 12Z-00Z TIME FRAME
(UNLESS CONVECTION CAN CLIP FAR EASTERN ZONES DURING THE AFTERNOON)
WITH FORECAST 12H QPF UNDER 0.25 INCH THOUGH COULD BE HIGHER ACROSS
EASTERN UPPER/FAR NORTHEAST LOWER GIVEN THE ABOVE CAVEATS.  TRACK OF
THE LOW RIGHT ACROSS LOWER MICHIGAN WILL LEAD TO SOME TRICKY
TEMPERATURE FORECASTS...IN GENERAL COOLER WEST AND WARMER EAST WITH
FALLING TEMPERATURES DURING THE MID/LATE AFTERNOON AS WINDS SWITCH
AROUND TO A MORE WESTERLY COMPONENT.

WHAT REMAINS OF DEFORMATION PRECIP BAND EXPECTED TO LIFT NORTHEAST
ACROSS NORTHERN MICHIGAN MONDAY EVENING...AFTER THAT MAY BE ON THE
QUIET SIDE OVERNIGHT AND WILL CONFINE POPS TO THE EVENING HOURS.
PRECIP TYPE MAY BE IN QUESTION ACROSS EASTERN UPPER AS DEPTH OF
SURFACE BASED WARM LAYER SHRINKS.  AS NORTHERN BRANCH SHORT WAVE
TROUGHS START GETTING INVOLVED IN THE FORECAST SCENARIO CAN`T RULE
OUT SOME ADDITIONAL SHOWERS DEVELOPING OVERNIGHT INTO TUESDAY
MORNING BUT NOT CONVINCED THE PROBABILITY RISES TO A SUFFICIENT
LEVEL TO INCLUDE IN THE FORECAST...WILL LEAVE IT OUT AND MAINTAIN
CONTINUITY.

TUESDAY...DEEP LAYER CYCLONIC FLOW ACROSS THE UPPER LAKES SPELLS
UNSETTLED AND NOT WARM WEATHER FOR TUESDAY.  DEEP MOISTURE WILL
ROTATE AROUND THE SOUTH SIDE OF THE UPPER LOW...AND COOL
TEMPERATURES ALOFT (AT OR BELOW -30C/500MB) WILL ADD A DIURNAL
COMPONENT TO SUPPORT SHOWERS...AND GIVEN COOL TEMPERATURES PRECIP
COULD FALL AS RAIN/SNOW/GRAUPEL.  GUSTY SOUTHWEST WINDS (20-30MPH
GUSTS PROBABLE NORTHERN LOWER) WON`T MAKE IT FEEL ANY WARMER...WITH
AFTERNOON HIGHS AROUND 40-MID 40S (10-15 DEGREES BELOW NORMAL).
SHOWERS WILL CONTINUE INTO TUESDAY NIGHT...COVERAGE MAY DECREASE
WITH ON DOWNWARD SIDE OF DIURNAL HEATING CYCLE BUT THEY WILL STILL
BE AROUND.  COOLING TEMPERATURES ALSO WILL TREND PRECIPITATION TO
ALL SNOW SHOWERS TUESDAY EVENING.

WEDNESDAY...MORE OF THE SAME FOR WEDNESDAY WITH CONTINUED COOL
CYCLONIC FLOW AND VARIOUS DISTURBANCES ROTATING AROUND THE PARENT
VORTEX.  HIGH TEMPERATURES PROBABLY A FEW DEGREES COOLER WEDNESDAY
AFTERNOON...WITH MORE TEMPERATURES STUCK BELOW 40 DEGREES LIKELY.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

THE PERIOD PICKS UP JUST AS THE PREVIOUS LEFT OFF WITH UPPER LEVEL
TROUGHING OVERHEAD AND MULTIPLE WEAK WAVES ROTATING THROUGH THE BASE
OF THE TROUGH...BRINGING RAIN/SNOW SHOWER CHANCES WEDNESDAY NIGHT
AND INTO THE DAY THURSDAY. AS MENTIONED BY PRIOR SHIFT...THE
MOVEMENT OF THE OVERALL PATTERN LOOKS MINIMAL THROUGH THE WEEKEND
WITH TROUGHING CLOSE ENOUGH WHERE ANY SUBTLE WAVE COULD KICK OFF
ADDITIONAL SHOWER ACTIVITY. HAVE GONE AHEAD AND ADDED LOW END CHANCE
POPS FOR THURSDAY NIGHT (MAINLY DIRECTLY DOWNWIND OF LAKE MICHIGAN
AND FOR THE EASTERN U.P.)...BUT WILL KEEP A MAINLY DRY FORECAST FROM
FRIDAY THROUGH SUNDAY AS THE MAJORITY OF THE TIME LOOKS TO REMAIN
PRECIPITATION FREE.

NO DOUBT THE OVERALL PATTERN WILL BE A RATHER CHILLY ONE...WITH H8
TEMPS APPROACHING -8C THROUGHOUT THE PERIOD. A BLENDED MODEL
GUIDANCE APPROACH WOULD SUGGEST HIGH TEMPERATURES STUCK IN THE UPPER
30S AND 40S (A SOLID 10-15 DEGREES BELOW NORMAL) AND LOWS MAINLY IN
THE 20S TO LOWER 30S.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 737 PM EDT SUN APR 19 2015

CONDITIONS DETERIORATING TO IFR TONIGHT. SOME IMPROVEMENT MONDAY.

LOW PRESSURE IN W CENTRAL INDIANA WILL LIFT NORTH...CROSSING
NORTHERN LOWER MI MONDAY MORNING. RAIN SHIELD IS SLOWLY ADVANCING
NORTH INTO CENTRAL LOWER MI...WITH SOME SHRA DEVELOPING OUT AHEAD.
RAIN WILL STEADILY ADVANCE INTO THE REGION TONIGHT...RESULTING IN
LOWERING CIGS/VSBYS WITH TIMES. ALL SITES SHOULD SEE IFR CIGS FOR
A PERIOD LATE TONIGHT INTO MONDAY MORNING. IMPROVING TO MVFR
DURING THE DAY MONDAY...THOUGH WITH SOME -SHRA LINGERING.

GUSTY EAST WINDS WILL LIGHTEN UP OVERNIGHT...WITH SOMEWHAT
BLUSTERY WEST WINDS DEVELOPING BY MONDAY AFTERNOON.

&&

.MARINE...
ISSUED AT 402 PM EDT SUN APR 19 2015

TONIGHT THROUGH TUESDAY...EAST WINDS AHEAD OF THE SFC LOW WILL
CONTINUE TO INCREASE ACROSS THE UPPER GREAT LAKES AS THE PRESSURE
GRADIENT TIGHTENS UP ESPECIALLY OVER LAKE HURON AND E UPPER. THE SFC
LOW MOVES OVER N LAKE MICHIGAN AND IT LOOKS LIKE THE GRADIENT SHOULD
JUST BE SLACK ENOUGH FOR THE WINDS TO REMAIN BELOW MOST OF THE SMALL
CRAFT CRITERIA IN THE NEARSHORE WATERS. ONCE THE SFC LOW MOVES NORTH
OF THE UPPER MICHIGAN, THE PRESSURE GRADIENT WILL TIGHTEN BRIEFLY
OVER THE UPPER GREAT LAKES BRINGING SMALL CRAFT CRITERIA TO MOST, IF
NOT ALL OF THE NEARSHORES MONDAY AFTERNOON AND MONDAY NIGHT.
TUESDAY, AS THE SFC LOW STALLS NORTH OF LAKE SUPERIOR, THE WINDS
WILL INCREASE AS THE GRADIENT AGAIN TIGHTENS, AND THEN RELAXES BY
THE AFTERNOON.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LSZ321-322.

&&

$$

NEAR TERM...JSL
SHORT TERM...JPB
LONG TERM...GILLEN
AVIATION...JAZ
MARINE...JSL




000
FXUS63 KAPX 192337
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
737 PM EDT SUN APR 19 2015

.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 402 PM EDT SUN APR 19 2015

HIGH IMPACT WEATHER: MINIMAL

FORECAST CHALLENGE: TIMING OF THE RAIN TONIGHT.

OVERVIEW...WHILE THE MOISTURE HAS BEEN INCREASING ALONG THE LAKE
HURON SHORE AND INLAND OF NE LOWER, NW LOWER HAS BEEN DRYING OUT
WITH A GOOD PORTION OF THE AREA WEST OF I-75 HAVING FALLEN BELOW
25%. IN E UPPER, THE RH HAS BEEN BETWEEN 40% AND 45%. WHAT THIS IS
DOING IS DELAYING THE RAIN SHIELD`S TRAVEL NORTH, WHICH HAD JUST
MADE IT TO THE MICHIGAN/INDIANA BORDER AROUND 19Z. USING THE TIMING
TOOL ON AWIPS, IT LOOKS LIKE THE RAIN SHOULD GET TO THE M-55
CORRIDOR AROUND 23Z, M-72 AROUND 00Z, M-32 AROUND 01Z, AND THE
STRAIT BETWEEN 02Z AND 03Z.

DETAILS FOR TONIGHT...AS WAS MENTIONED, TRYING TO TIME THIS SYSTEM
WITH THE DRY AIR IN THE LOWER LEVELS IS MADDENING. THE QUESTION
ISN`T IF THE AIR WILL LEAVE, BUT WHEN AS THE SFC LOW WILL, AS IT
MOVES UP FROM THE MID-MISSISSIPPI VALLEY, OVERWHELM WITH DRY AIR
WITH ITS MOISTURE, AND ALLOW THE RAIN TO FALL ALL THE WAY TO THE
SFC. HOWEVER, ONCE THE RAIN STARTS, IT WILL FALL THROUGH THE NIGHT
AS THE SFC NORTH OVER THE WESTERN PART OF THE STATE BETWEEN 06Z AND
12Z. THIS SFC LOW AND ASSOCIATED 500 MB SHORTWAVE TROUGH AND 50 KNOT
SPEED MAX THAT MOVES OVER THE STATE, OVER THE WARM FRONT. WITH THE
PWAT AROUND 1.0" OVERNIGHT OVER THE FORECAST AREA, WILL EXPECT
THAT A DECENT STEADY RAIN WILL RESULT.

&&

.SHORT TERM...(MONDAY THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

...SHOWERY/COOL/UNSETTLED THROUGH MIDWEEK...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: WELL-DEFINED SPLIT FLOW PATTERN FROM THE
END OF LAST WEEK NOW CONSOLIDATING AS NORTHERN BRANCH SHORT WAVE
TROUGH DIGS SOUTHEAST FROM WESTERN CANADA AND SCOOPS UP PESKY
SOUTHERN BRANCH VORTEX THAT HAS BEEN SPINNING ACROSS THE GREAT
BASIN/SOUTHERN ROCKIES SINCE THE MIDDLE OF LAST WEEK.  POSITIVE
PACIFIC TELECONNECTIONS LEADING TO A MORE AMPLIFIED PATTERN (BIG
TROUGH EAST OF THE DATELINE WITH +PNA RIDGING ALONG THE WEST COAST
OF NORTH AMERICA.  THIS CONSOLIDATING CENTRAL NORTH AMERICAN TROUGH
WILL BECOME THE PREDOMINANT WEATHER FEATURE THIS WEEK AS IT TAKES UP
RESIDENCE WITH REX BLOCKING ALONG THE WEST COAST...WITH AN UPPER LOW
EVENTUALLY PARKING ITSELF OVER THE GREAT LAKES BY MIDWEEK.

SOUTHERN BRANCH DISTURBANCE LOOKS TO COME OUT IN TWO PIECES
MONDAY...WHILE CLOSED CIRCULATION ALOFT DEVELOPS OVER NORTHWEST
ONTARIO/UPPER MIDWEST.  UPPER LOW THEN SETTLES OVER LAKE SUPERIOR
TUESDAY AND HANGS IN THROUGH MIDWEEK.  AT THE SURFACE...LEAD
SOUTHERN BRANCH SHORT WAVE TROUGH HAS AN ASSOCIATED SURFACE LOW OVER
THE MID MISSISSIPPI VALLEY THAT IS FORECAST TO DEEPEN AND LIFT NORTH
INTO LOWER MICHIGAN BY MONDAY MORNING...PROBABLY BELOW 990MB WHICH
IS PRETTY SIGNIFICANT BY MID-APRIL STANDARDS.  THIS LOW WILL PULL
COOLER AIR INTO MICHIGAN STARTING MONDAY NIGHT...CYCLONIC FLOW
LINGERS INTO MIDWEEK.

PRIMARY FORECAST CONCERNS: VARYING PRECIPITATION CHANCES THROUGH
MIDWEEK...AS WELL AS PRECIPITATION TYPE.

MONDAY...12Z SOUNDINGS AND GOES SOUNDER IMAGERY SHOWS A NICE SURGE
OF MOISTURE COMING UP ACROSS THE SOUTHEASTERN STATES (1.00-1.50 INCH
PRECIPITABLE WATER) WHICH IS PUSHING A LARGE ARE OF RAIN NORTHWARD
ACROSS THE OHIO VALLEY...AND EVENTUALLY INTO MICHIGAN TONIGHT/MONDAY
MORNING.  THIS WILL PUSH THROUGH THE FORECAST AREA MONDAY MORNING
(PERHAPS FAIRLY QUICKLY) WITH MID LEVEL DRYING (POSSIBLY TAPERING
OFF TO A PERIOD OF DRIZZLE).  SURFACE LOW TRACKS ACROSS NORTHERN
LOWER MONDAY MORNING...BEHIND THAT A LINGERING BAND OF DEFORMATION/
FRONTOGENETIC PRECIPITATION WILL ROTATE IN FROM THE WEST DURING THE
AFTERNOON HOURS.  IN ADDITION...COULD SEE SOME CONVECTIVE PRECIP
CLOSE TO THE SOUTHEAST PORTION OF THE FORECAST AREA DURING THE LATE
MORNING/AFTERNOON WITH SOME ELEVATED INSTABILITY (TQ INDICES
POTENTIALLY IN THE 16-20C RANGE NEAR LOW LEVEL THETA-E RIDGE) AND
SECOND PIECE OF SOUTHERN BRANCH ENERGY SWINGING NORTHEAST ACROSS THE
LOWER PENINSULA.  MORE LIKELY THIS ACTIVITY WOULD OCCUR ACROSS THE
THUMB INTO LAKE HURON...BUT MAY BE CLOSE.  WILL NOT TRY AND VARY
PRECIP PROBABILITIES IN THE FORECAST GRIDS TO ACCOUNT FOR TIMING OF
VARIOUS WAVES OF PRECIPITATION (AS IT WILL BE WRONG ANYHOW)...WITH A
GENERIC HIGH LIKELY/CATEGORICAL POP THROUGH THE DAY SUFFICIENT FOR
NOW. AS LONG AS INITIAL AREA OF RAIN SCOOTS NORTH QUICKLY MONDAY
MORNING... NOT EXPECT A LOT OF RAINFALL IN THE 12Z-00Z TIME FRAME
(UNLESS CONVECTION CAN CLIP FAR EASTERN ZONES DURING THE AFTERNOON)
WITH FORECAST 12H QPF UNDER 0.25 INCH THOUGH COULD BE HIGHER ACROSS
EASTERN UPPER/FAR NORTHEAST LOWER GIVEN THE ABOVE CAVEATS.  TRACK OF
THE LOW RIGHT ACROSS LOWER MICHIGAN WILL LEAD TO SOME TRICKY
TEMPERATURE FORECASTS...IN GENERAL COOLER WEST AND WARMER EAST WITH
FALLING TEMPERATURES DURING THE MID/LATE AFTERNOON AS WINDS SWITCH
AROUND TO A MORE WESTERLY COMPONENT.

WHAT REMAINS OF DEFORMATION PRECIP BAND EXPECTED TO LIFT NORTHEAST
ACROSS NORTHERN MICHIGAN MONDAY EVENING...AFTER THAT MAY BE ON THE
QUIET SIDE OVERNIGHT AND WILL CONFINE POPS TO THE EVENING HOURS.
PRECIP TYPE MAY BE IN QUESTION ACROSS EASTERN UPPER AS DEPTH OF
SURFACE BASED WARM LAYER SHRINKS.  AS NORTHERN BRANCH SHORT WAVE
TROUGHS START GETTING INVOLVED IN THE FORECAST SCENARIO CAN`T RULE
OUT SOME ADDITIONAL SHOWERS DEVELOPING OVERNIGHT INTO TUESDAY
MORNING BUT NOT CONVINCED THE PROBABILITY RISES TO A SUFFICIENT
LEVEL TO INCLUDE IN THE FORECAST...WILL LEAVE IT OUT AND MAINTAIN
CONTINUITY.

TUESDAY...DEEP LAYER CYCLONIC FLOW ACROSS THE UPPER LAKES SPELLS
UNSETTLED AND NOT WARM WEATHER FOR TUESDAY.  DEEP MOISTURE WILL
ROTATE AROUND THE SOUTH SIDE OF THE UPPER LOW...AND COOL
TEMPERATURES ALOFT (AT OR BELOW -30C/500MB) WILL ADD A DIURNAL
COMPONENT TO SUPPORT SHOWERS...AND GIVEN COOL TEMPERATURES PRECIP
COULD FALL AS RAIN/SNOW/GRAUPEL.  GUSTY SOUTHWEST WINDS (20-30MPH
GUSTS PROBABLE NORTHERN LOWER) WON`T MAKE IT FEEL ANY WARMER...WITH
AFTERNOON HIGHS AROUND 40-MID 40S (10-15 DEGREES BELOW NORMAL).
SHOWERS WILL CONTINUE INTO TUESDAY NIGHT...COVERAGE MAY DECREASE
WITH ON DOWNWARD SIDE OF DIURNAL HEATING CYCLE BUT THEY WILL STILL
BE AROUND.  COOLING TEMPERATURES ALSO WILL TREND PRECIPITATION TO
ALL SNOW SHOWERS TUESDAY EVENING.

WEDNESDAY...MORE OF THE SAME FOR WEDNESDAY WITH CONTINUED COOL
CYCLONIC FLOW AND VARIOUS DISTURBANCES ROTATING AROUND THE PARENT
VORTEX.  HIGH TEMPERATURES PROBABLY A FEW DEGREES COOLER WEDNESDAY
AFTERNOON...WITH MORE TEMPERATURES STUCK BELOW 40 DEGREES LIKELY.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

THE PERIOD PICKS UP JUST AS THE PREVIOUS LEFT OFF WITH UPPER LEVEL
TROUGHING OVERHEAD AND MULTIPLE WEAK WAVES ROTATING THROUGH THE BASE
OF THE TROUGH...BRINGING RAIN/SNOW SHOWER CHANCES WEDNESDAY NIGHT
AND INTO THE DAY THURSDAY. AS MENTIONED BY PRIOR SHIFT...THE
MOVEMENT OF THE OVERALL PATTERN LOOKS MINIMAL THROUGH THE WEEKEND
WITH TROUGHING CLOSE ENOUGH WHERE ANY SUBTLE WAVE COULD KICK OFF
ADDITIONAL SHOWER ACTIVITY. HAVE GONE AHEAD AND ADDED LOW END CHANCE
POPS FOR THURSDAY NIGHT (MAINLY DIRECTLY DOWNWIND OF LAKE MICHIGAN
AND FOR THE EASTERN U.P.)...BUT WILL KEEP A MAINLY DRY FORECAST FROM
FRIDAY THROUGH SUNDAY AS THE MAJORITY OF THE TIME LOOKS TO REMAIN
PRECIPITATION FREE.

NO DOUBT THE OVERALL PATTERN WILL BE A RATHER CHILLY ONE...WITH H8
TEMPS APPROACHING -8C THROUGHOUT THE PERIOD. A BLENDED MODEL
GUIDANCE APPROACH WOULD SUGGEST HIGH TEMPERATURES STUCK IN THE UPPER
30S AND 40S (A SOLID 10-15 DEGREES BELOW NORMAL) AND LOWS MAINLY IN
THE 20S TO LOWER 30S.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 737 PM EDT SUN APR 19 2015

CONDITIONS DETERIORATING TO IFR TONIGHT. SOME IMPROVEMENT MONDAY.

LOW PRESSURE IN W CENTRAL INDIANA WILL LIFT NORTH...CROSSING
NORTHERN LOWER MI MONDAY MORNING. RAIN SHIELD IS SLOWLY ADVANCING
NORTH INTO CENTRAL LOWER MI...WITH SOME SHRA DEVELOPING OUT AHEAD.
RAIN WILL STEADILY ADVANCE INTO THE REGION TONIGHT...RESULTING IN
LOWERING CIGS/VSBYS WITH TIMES. ALL SITES SHOULD SEE IFR CIGS FOR
A PERIOD LATE TONIGHT INTO MONDAY MORNING. IMPROVING TO MVFR
DURING THE DAY MONDAY...THOUGH WITH SOME -SHRA LINGERING.

GUSTY EAST WINDS WILL LIGHTEN UP OVERNIGHT...WITH SOMEWHAT
BLUSTERY WEST WINDS DEVELOPING BY MONDAY AFTERNOON.

&&

.MARINE...
ISSUED AT 402 PM EDT SUN APR 19 2015

TONIGHT THROUGH TUESDAY...EAST WINDS AHEAD OF THE SFC LOW WILL
CONTINUE TO INCREASE ACROSS THE UPPER GREAT LAKES AS THE PRESSURE
GRADIENT TIGHTENS UP ESPECIALLY OVER LAKE HURON AND E UPPER. THE SFC
LOW MOVES OVER N LAKE MICHIGAN AND IT LOOKS LIKE THE GRADIENT SHOULD
JUST BE SLACK ENOUGH FOR THE WINDS TO REMAIN BELOW MOST OF THE SMALL
CRAFT CRITERIA IN THE NEARSHORE WATERS. ONCE THE SFC LOW MOVES NORTH
OF THE UPPER MICHIGAN, THE PRESSURE GRADIENT WILL TIGHTEN BRIEFLY
OVER THE UPPER GREAT LAKES BRINGING SMALL CRAFT CRITERIA TO MOST, IF
NOT ALL OF THE NEARSHORES MONDAY AFTERNOON AND MONDAY NIGHT.
TUESDAY, AS THE SFC LOW STALLS NORTH OF LAKE SUPERIOR, THE WINDS
WILL INCREASE AS THE GRADIENT AGAIN TIGHTENS, AND THEN RELAXES BY
THE AFTERNOON.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LSZ321-322.

&&

$$

NEAR TERM...JSL
SHORT TERM...JPB
LONG TERM...GILLEN
AVIATION...JAZ
MARINE...JSL




000
FXUS63 KAPX 192337
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
737 PM EDT SUN APR 19 2015

.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 402 PM EDT SUN APR 19 2015

HIGH IMPACT WEATHER: MINIMAL

FORECAST CHALLENGE: TIMING OF THE RAIN TONIGHT.

OVERVIEW...WHILE THE MOISTURE HAS BEEN INCREASING ALONG THE LAKE
HURON SHORE AND INLAND OF NE LOWER, NW LOWER HAS BEEN DRYING OUT
WITH A GOOD PORTION OF THE AREA WEST OF I-75 HAVING FALLEN BELOW
25%. IN E UPPER, THE RH HAS BEEN BETWEEN 40% AND 45%. WHAT THIS IS
DOING IS DELAYING THE RAIN SHIELD`S TRAVEL NORTH, WHICH HAD JUST
MADE IT TO THE MICHIGAN/INDIANA BORDER AROUND 19Z. USING THE TIMING
TOOL ON AWIPS, IT LOOKS LIKE THE RAIN SHOULD GET TO THE M-55
CORRIDOR AROUND 23Z, M-72 AROUND 00Z, M-32 AROUND 01Z, AND THE
STRAIT BETWEEN 02Z AND 03Z.

DETAILS FOR TONIGHT...AS WAS MENTIONED, TRYING TO TIME THIS SYSTEM
WITH THE DRY AIR IN THE LOWER LEVELS IS MADDENING. THE QUESTION
ISN`T IF THE AIR WILL LEAVE, BUT WHEN AS THE SFC LOW WILL, AS IT
MOVES UP FROM THE MID-MISSISSIPPI VALLEY, OVERWHELM WITH DRY AIR
WITH ITS MOISTURE, AND ALLOW THE RAIN TO FALL ALL THE WAY TO THE
SFC. HOWEVER, ONCE THE RAIN STARTS, IT WILL FALL THROUGH THE NIGHT
AS THE SFC NORTH OVER THE WESTERN PART OF THE STATE BETWEEN 06Z AND
12Z. THIS SFC LOW AND ASSOCIATED 500 MB SHORTWAVE TROUGH AND 50 KNOT
SPEED MAX THAT MOVES OVER THE STATE, OVER THE WARM FRONT. WITH THE
PWAT AROUND 1.0" OVERNIGHT OVER THE FORECAST AREA, WILL EXPECT
THAT A DECENT STEADY RAIN WILL RESULT.

&&

.SHORT TERM...(MONDAY THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

...SHOWERY/COOL/UNSETTLED THROUGH MIDWEEK...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: WELL-DEFINED SPLIT FLOW PATTERN FROM THE
END OF LAST WEEK NOW CONSOLIDATING AS NORTHERN BRANCH SHORT WAVE
TROUGH DIGS SOUTHEAST FROM WESTERN CANADA AND SCOOPS UP PESKY
SOUTHERN BRANCH VORTEX THAT HAS BEEN SPINNING ACROSS THE GREAT
BASIN/SOUTHERN ROCKIES SINCE THE MIDDLE OF LAST WEEK.  POSITIVE
PACIFIC TELECONNECTIONS LEADING TO A MORE AMPLIFIED PATTERN (BIG
TROUGH EAST OF THE DATELINE WITH +PNA RIDGING ALONG THE WEST COAST
OF NORTH AMERICA.  THIS CONSOLIDATING CENTRAL NORTH AMERICAN TROUGH
WILL BECOME THE PREDOMINANT WEATHER FEATURE THIS WEEK AS IT TAKES UP
RESIDENCE WITH REX BLOCKING ALONG THE WEST COAST...WITH AN UPPER LOW
EVENTUALLY PARKING ITSELF OVER THE GREAT LAKES BY MIDWEEK.

SOUTHERN BRANCH DISTURBANCE LOOKS TO COME OUT IN TWO PIECES
MONDAY...WHILE CLOSED CIRCULATION ALOFT DEVELOPS OVER NORTHWEST
ONTARIO/UPPER MIDWEST.  UPPER LOW THEN SETTLES OVER LAKE SUPERIOR
TUESDAY AND HANGS IN THROUGH MIDWEEK.  AT THE SURFACE...LEAD
SOUTHERN BRANCH SHORT WAVE TROUGH HAS AN ASSOCIATED SURFACE LOW OVER
THE MID MISSISSIPPI VALLEY THAT IS FORECAST TO DEEPEN AND LIFT NORTH
INTO LOWER MICHIGAN BY MONDAY MORNING...PROBABLY BELOW 990MB WHICH
IS PRETTY SIGNIFICANT BY MID-APRIL STANDARDS.  THIS LOW WILL PULL
COOLER AIR INTO MICHIGAN STARTING MONDAY NIGHT...CYCLONIC FLOW
LINGERS INTO MIDWEEK.

PRIMARY FORECAST CONCERNS: VARYING PRECIPITATION CHANCES THROUGH
MIDWEEK...AS WELL AS PRECIPITATION TYPE.

MONDAY...12Z SOUNDINGS AND GOES SOUNDER IMAGERY SHOWS A NICE SURGE
OF MOISTURE COMING UP ACROSS THE SOUTHEASTERN STATES (1.00-1.50 INCH
PRECIPITABLE WATER) WHICH IS PUSHING A LARGE ARE OF RAIN NORTHWARD
ACROSS THE OHIO VALLEY...AND EVENTUALLY INTO MICHIGAN TONIGHT/MONDAY
MORNING.  THIS WILL PUSH THROUGH THE FORECAST AREA MONDAY MORNING
(PERHAPS FAIRLY QUICKLY) WITH MID LEVEL DRYING (POSSIBLY TAPERING
OFF TO A PERIOD OF DRIZZLE).  SURFACE LOW TRACKS ACROSS NORTHERN
LOWER MONDAY MORNING...BEHIND THAT A LINGERING BAND OF DEFORMATION/
FRONTOGENETIC PRECIPITATION WILL ROTATE IN FROM THE WEST DURING THE
AFTERNOON HOURS.  IN ADDITION...COULD SEE SOME CONVECTIVE PRECIP
CLOSE TO THE SOUTHEAST PORTION OF THE FORECAST AREA DURING THE LATE
MORNING/AFTERNOON WITH SOME ELEVATED INSTABILITY (TQ INDICES
POTENTIALLY IN THE 16-20C RANGE NEAR LOW LEVEL THETA-E RIDGE) AND
SECOND PIECE OF SOUTHERN BRANCH ENERGY SWINGING NORTHEAST ACROSS THE
LOWER PENINSULA.  MORE LIKELY THIS ACTIVITY WOULD OCCUR ACROSS THE
THUMB INTO LAKE HURON...BUT MAY BE CLOSE.  WILL NOT TRY AND VARY
PRECIP PROBABILITIES IN THE FORECAST GRIDS TO ACCOUNT FOR TIMING OF
VARIOUS WAVES OF PRECIPITATION (AS IT WILL BE WRONG ANYHOW)...WITH A
GENERIC HIGH LIKELY/CATEGORICAL POP THROUGH THE DAY SUFFICIENT FOR
NOW. AS LONG AS INITIAL AREA OF RAIN SCOOTS NORTH QUICKLY MONDAY
MORNING... NOT EXPECT A LOT OF RAINFALL IN THE 12Z-00Z TIME FRAME
(UNLESS CONVECTION CAN CLIP FAR EASTERN ZONES DURING THE AFTERNOON)
WITH FORECAST 12H QPF UNDER 0.25 INCH THOUGH COULD BE HIGHER ACROSS
EASTERN UPPER/FAR NORTHEAST LOWER GIVEN THE ABOVE CAVEATS.  TRACK OF
THE LOW RIGHT ACROSS LOWER MICHIGAN WILL LEAD TO SOME TRICKY
TEMPERATURE FORECASTS...IN GENERAL COOLER WEST AND WARMER EAST WITH
FALLING TEMPERATURES DURING THE MID/LATE AFTERNOON AS WINDS SWITCH
AROUND TO A MORE WESTERLY COMPONENT.

WHAT REMAINS OF DEFORMATION PRECIP BAND EXPECTED TO LIFT NORTHEAST
ACROSS NORTHERN MICHIGAN MONDAY EVENING...AFTER THAT MAY BE ON THE
QUIET SIDE OVERNIGHT AND WILL CONFINE POPS TO THE EVENING HOURS.
PRECIP TYPE MAY BE IN QUESTION ACROSS EASTERN UPPER AS DEPTH OF
SURFACE BASED WARM LAYER SHRINKS.  AS NORTHERN BRANCH SHORT WAVE
TROUGHS START GETTING INVOLVED IN THE FORECAST SCENARIO CAN`T RULE
OUT SOME ADDITIONAL SHOWERS DEVELOPING OVERNIGHT INTO TUESDAY
MORNING BUT NOT CONVINCED THE PROBABILITY RISES TO A SUFFICIENT
LEVEL TO INCLUDE IN THE FORECAST...WILL LEAVE IT OUT AND MAINTAIN
CONTINUITY.

TUESDAY...DEEP LAYER CYCLONIC FLOW ACROSS THE UPPER LAKES SPELLS
UNSETTLED AND NOT WARM WEATHER FOR TUESDAY.  DEEP MOISTURE WILL
ROTATE AROUND THE SOUTH SIDE OF THE UPPER LOW...AND COOL
TEMPERATURES ALOFT (AT OR BELOW -30C/500MB) WILL ADD A DIURNAL
COMPONENT TO SUPPORT SHOWERS...AND GIVEN COOL TEMPERATURES PRECIP
COULD FALL AS RAIN/SNOW/GRAUPEL.  GUSTY SOUTHWEST WINDS (20-30MPH
GUSTS PROBABLE NORTHERN LOWER) WON`T MAKE IT FEEL ANY WARMER...WITH
AFTERNOON HIGHS AROUND 40-MID 40S (10-15 DEGREES BELOW NORMAL).
SHOWERS WILL CONTINUE INTO TUESDAY NIGHT...COVERAGE MAY DECREASE
WITH ON DOWNWARD SIDE OF DIURNAL HEATING CYCLE BUT THEY WILL STILL
BE AROUND.  COOLING TEMPERATURES ALSO WILL TREND PRECIPITATION TO
ALL SNOW SHOWERS TUESDAY EVENING.

WEDNESDAY...MORE OF THE SAME FOR WEDNESDAY WITH CONTINUED COOL
CYCLONIC FLOW AND VARIOUS DISTURBANCES ROTATING AROUND THE PARENT
VORTEX.  HIGH TEMPERATURES PROBABLY A FEW DEGREES COOLER WEDNESDAY
AFTERNOON...WITH MORE TEMPERATURES STUCK BELOW 40 DEGREES LIKELY.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

THE PERIOD PICKS UP JUST AS THE PREVIOUS LEFT OFF WITH UPPER LEVEL
TROUGHING OVERHEAD AND MULTIPLE WEAK WAVES ROTATING THROUGH THE BASE
OF THE TROUGH...BRINGING RAIN/SNOW SHOWER CHANCES WEDNESDAY NIGHT
AND INTO THE DAY THURSDAY. AS MENTIONED BY PRIOR SHIFT...THE
MOVEMENT OF THE OVERALL PATTERN LOOKS MINIMAL THROUGH THE WEEKEND
WITH TROUGHING CLOSE ENOUGH WHERE ANY SUBTLE WAVE COULD KICK OFF
ADDITIONAL SHOWER ACTIVITY. HAVE GONE AHEAD AND ADDED LOW END CHANCE
POPS FOR THURSDAY NIGHT (MAINLY DIRECTLY DOWNWIND OF LAKE MICHIGAN
AND FOR THE EASTERN U.P.)...BUT WILL KEEP A MAINLY DRY FORECAST FROM
FRIDAY THROUGH SUNDAY AS THE MAJORITY OF THE TIME LOOKS TO REMAIN
PRECIPITATION FREE.

NO DOUBT THE OVERALL PATTERN WILL BE A RATHER CHILLY ONE...WITH H8
TEMPS APPROACHING -8C THROUGHOUT THE PERIOD. A BLENDED MODEL
GUIDANCE APPROACH WOULD SUGGEST HIGH TEMPERATURES STUCK IN THE UPPER
30S AND 40S (A SOLID 10-15 DEGREES BELOW NORMAL) AND LOWS MAINLY IN
THE 20S TO LOWER 30S.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 737 PM EDT SUN APR 19 2015

CONDITIONS DETERIORATING TO IFR TONIGHT. SOME IMPROVEMENT MONDAY.

LOW PRESSURE IN W CENTRAL INDIANA WILL LIFT NORTH...CROSSING
NORTHERN LOWER MI MONDAY MORNING. RAIN SHIELD IS SLOWLY ADVANCING
NORTH INTO CENTRAL LOWER MI...WITH SOME SHRA DEVELOPING OUT AHEAD.
RAIN WILL STEADILY ADVANCE INTO THE REGION TONIGHT...RESULTING IN
LOWERING CIGS/VSBYS WITH TIMES. ALL SITES SHOULD SEE IFR CIGS FOR
A PERIOD LATE TONIGHT INTO MONDAY MORNING. IMPROVING TO MVFR
DURING THE DAY MONDAY...THOUGH WITH SOME -SHRA LINGERING.

GUSTY EAST WINDS WILL LIGHTEN UP OVERNIGHT...WITH SOMEWHAT
BLUSTERY WEST WINDS DEVELOPING BY MONDAY AFTERNOON.

&&

.MARINE...
ISSUED AT 402 PM EDT SUN APR 19 2015

TONIGHT THROUGH TUESDAY...EAST WINDS AHEAD OF THE SFC LOW WILL
CONTINUE TO INCREASE ACROSS THE UPPER GREAT LAKES AS THE PRESSURE
GRADIENT TIGHTENS UP ESPECIALLY OVER LAKE HURON AND E UPPER. THE SFC
LOW MOVES OVER N LAKE MICHIGAN AND IT LOOKS LIKE THE GRADIENT SHOULD
JUST BE SLACK ENOUGH FOR THE WINDS TO REMAIN BELOW MOST OF THE SMALL
CRAFT CRITERIA IN THE NEARSHORE WATERS. ONCE THE SFC LOW MOVES NORTH
OF THE UPPER MICHIGAN, THE PRESSURE GRADIENT WILL TIGHTEN BRIEFLY
OVER THE UPPER GREAT LAKES BRINGING SMALL CRAFT CRITERIA TO MOST, IF
NOT ALL OF THE NEARSHORES MONDAY AFTERNOON AND MONDAY NIGHT.
TUESDAY, AS THE SFC LOW STALLS NORTH OF LAKE SUPERIOR, THE WINDS
WILL INCREASE AS THE GRADIENT AGAIN TIGHTENS, AND THEN RELAXES BY
THE AFTERNOON.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LSZ321-322.

&&

$$

NEAR TERM...JSL
SHORT TERM...JPB
LONG TERM...GILLEN
AVIATION...JAZ
MARINE...JSL




000
FXUS63 KDTX 192300
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
700 PM EDT SUN APR 19 2015


.AVIATION...

RAIN WILL CONTINUE EXPANDING ACROSS SE MI AND WILL OVERSPREAD THE
TERMINALS BY 00Z. EASTERLY WINDS HAVE BEEN SUSTAINING LOW LEVEL DRY
AIR WHICH IN TURN HAS HELD CEILINGS UP. A SUBSTANTIAL AMOUNT OF
MOISTURE ADVECTION DURING THE EVENING AND OVERNIGHT ALONG WITH
INCREASING INTENSITY OF RAINFALL WILL HOWEVER LEAD TO A STEADY
LOWERING TREND IN CEILINGS THIS EVENING. IFR CONDITIONS ARE EXPECT
TO DEVELOP EITHER LATE THIS EVENING OR EARLY IN THE OVERNIGHT
PERIOD. UPSTREAM OBSERVATIONS DO HOWEVER SUGGEST THERE IS LIKELY TO
BE A GOOD DEAL OF VARIABILITY IN CEILING HEIGHTS. THIS RAIN AND
MOISTURE THAT IS LIFTING ACROSS THE AREA IS ASSOCIATED WITH A LOW
PRESSURE SYSTEM OVER INDIANA. THIS LOW WILL LIFT ACROSS WESTERN
LOWER MI TONIGHT. EVEN WITH THE RAINFALL...THE SFC GRADIENT SHOULD
SUSTAIN SOME DEGREE OF GUSTINESS TO THE WINDS TONIGHT /POSSIBLY
TOPPING 20 KNOTS AT TIMES/. A WARM FRONT ASSOCIATED WITH THE SFC LOW
IS FORECAST TO LIFT NORTH ACROSS SE MI BETWEEN 09Z AND 12Z. THE
PASSAGE OF THIS FRONT WILL VEER WINDS TO THE SOUTH AND MAY ACTUALLY
LEAD TO SOME LIFTING OF CLOUD BASES AS THE WARM SECTOR NUDGES INTO
THE AREA.

FOR DTW...THE PEAK IN RAINFALL INTENSITY IS EXPECTED TO OCCUR
BETWEEN 02Z AND 05Z...WHERE SOME PERIODIC HEAVY RAINFALL IS
POSSIBLE. WHILE CEILING HEIGHTS WILL FLUCTUATE A GOOD DEAL...THE
OVERALL TREND HEADING INTO THE OVERNIGHT WILL BE FOR THE DEVELOPMENT
OF IFR CONDITIONS.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS AOB 5KFT TONIGHT AND MONDAY.

* LOW IN THUNDERSTORMS TONIGHT AND MONDAY.

&&

.PREV DISCUSSION...ISSUED 356 PM EDT SUN APR 19 2015

SHORT TERM...TONIGHT

THE ARC OF SHOWER ACTIVITY FORCED ON AN INITIAL SURGE/GRADIENT OF
850-700MB MOISTURE HAS STRUGGLED FROM A VIGOR PERSPECTIVE DUE TO A
LACK OF INSTABILITY. WITH SHOWERS WORKING UP THE FRONTAL SLOPE AS IT
TRACKS NORTHWARD...EXPECT THE WEAK NATURE TO CONTINUE.

THE MAIN BAND OF SYNOPTIC FORCING AND WIDESPREAD RAIN ACTIVITY WILL
LIFT ACROSS THE OHIO AND MICHIGAN BORDER AROUND 21Z. REGIONAL MOSAIC
AS OF 19Z... SHOWS THE MIDLEVELS SATURATING SOUTH OF TOLEDO. REALLY
A TREMENDOUS AMOUNT OF SYNOPTIC SCALE SUPPORT FOR LIFT AND
PRECIPITATION GENERATION TONIGHT AS SOUTHEASTERN MICHIGAN REMAINS
FAVORABLY POSITIONED AHEAD OF A HIGH AMPLITUDE WARM SECTOR
STRUCTURE AND OPTIMAL WARM AIR ADVECTION. EVERYTHING APPEARS TO BE
LINING UP FROM A FORCING STANDPOINT FOR A FAVORABLE PERIOD OF
WIDESPREAD RAIN INCLUDING A POTENTIAL FOR HEAVY RAINFALL.
SPECIFICALLY...LARGE BULLSEYE OF 1000-500MB HEIGHT FALLS...LINKAGE
OF RIGHT NOSE OF LOW LEVEL JET AXIS WITH RIGHT ENTRANCE REGION
DYNAMICS ALOFT...AND A DIRECT HIT FROM A SECONDARY VORTICITY
MAXIMUM. NWP SUPPORTS THIS SECONDARY VORTICITY MAXIMUM BECOMING
ORGANIZED/STRENGTHENING NEAR LOUISVILLE NOW AND LIFTING INTO FAR
SOUTHEASTERN MICHIGAN BETWEEN 00-03Z. NAM REALLY BITES ON THIS
FEATURE SHOWING DEPICTIONS OF A PSEUDO SHARS TYPE RESPONSE AND
HIGH AMOUNTS OF 3HR QPF. BROAD NATIONAL MOSAIC OF REFLECTIVITY
ALONG WITH SATELLITE IMAGERY OF CLEARING/DESTABILIZING STRAIGHT
INTO CENTRAL KENTUCKY SUPPORTS THIS STRONG SOLUTION OF THE
SECONDARY VORTICITY MAXIMUM. THUS...THE EARLIER FORECAST OF
FORECASTING QPF AMOUNTS OF UPWARDS OF 1.00 INCH FOR FAR
SOUTHEASTERN MICHIGAN INCLUDING THE DETROIT METRO APPEARS
REASONABLE. THERE AT LEAST REMAINS SOME POTENTIAL THAT THIS DRY
AIR/SLOT COULD WORK NORTHWARD AT A CRITICAL TRAJECTORY AND CAUSE
HEAVY PRECIPITATION TO DEFLECT AWAY FROM THE CWA. CONFIDENCE IN
PROJECTING THAT OUT IS LOW. WHILE FORECASTED QPF AMOUNTS ARE
RELATIVELY HIGH FROM AN EVENT STANDPOINT...THE STEADY NORTHWARD
PROGRESSION OF SHOWERS/EMBEDDED THUNDER WILL LIMIT THE CONCERN FOR
FLOODING.

LONG TERM...

STRONG LOW PRESSURE WILL CONTINUE TO DEEPEN AS IT LIFTS NORTHWARD
THROUGH NORTHERN LOWER MICHIGAN INTO ONTARIO ON MONDAY. MODELS HAVE
TRENDED SLIGHTLY SLOWLY AND FURTHER WEST WITH THE TRACK OF THIS
SYSTEM...AND THIS WILL MOSTLY LIKELY HAVE SOME NOTABLE IMPLICATIONS
TO THE GOING FORECAST. AS SUCH...HAVE MADE A FEW ADJUSTMENTS FOR
THIS PACKAGE.

THE "NEW" CONSENSUS TRACK FORECAST WILL ESSENTIALLY DELAY THE COLD
FRONTAL PASSAGE THROUGH THE AREA UNTIL LATE AFTERNOON AND ALLOW FOR
TEMPERATURES TO CLIMB WELL INTO THE 60S OVER A GOOD PORTION OF THE
AREA. THIS...IN TURN...WILL ALLOW FOR SOME DESTABILIZATION AS SBCAPE
VALUES CLIMB TO AROUND 500 J/KG BY AFTERNOON. THIS SHOULD ALLOW FOR
MORE VIGOROUS CONVECTION ALONG THE COLD FRONT WITH THE POTENTIAL FOR
HAIL INCREASING AS FREEZING LEVELS DROP BELOW 7000-8000 FEET AS COLD
AIR WRAP AROUND THE UPPER CIRCULATION.

IN ADDITION...THIS ACTIVITY WILL LIKELY PRODUCE SOME GUSTY WINDS AS
DEEP SWATH OF 35 TO 40 KT SOUTHWEST FLOW OVERSPREADS THE AREA. EVEN
OUTSIDE OF STORMS...WIND GUSTS WILL LIKELY REACH 35 MPH AT TIMES BY
AFTERNOON AND HAVE UPPED THE OVERALL FORECAST WINDS A FAIR AMOUNT.
WHILE WIDESPREAD STRONG STORMS ARE PROBABLY NOT TOO LIKELY...A FEW
WILL CERTAINLY BECOME A BIT ROBUST AS FORCING ALONG THE COLD FRONT
HELPS FOCUS THE MARGINAL INSTABILITY THAT IS ABLE TO BUILD OVER
PARTS OF THE AREA.

CONDITIONS WILL QUIET FROM MID EVENING INTO TUESDAY AS THE LOW LIFTS
TO NEAR JAMES BAY AND STALLS. THAT SAID...CONDITIONS WILL REMAIN
RATHER UNSETTLED INTO THE TUESDAY AND TUESDAY NIGHT PERIOD AS THIS
LOW ONLY GRADUALLY WEAKENS. EXPECT COOLER TEMPERATURES AND CONTINUE
GUSTY WINDS WITH SCATTERED RAIN SHOWERS DOTTING THE REGION...MAINLY
IN THE TUESDAY AFTERNOON PERIOD DURING THE DIURNAL TEMPERATURE AND
INSTABILITY MAX. DOWNSLOPING WEST/SOUTHWEST FLOW SHOULD ALLOW METRO
DETROIT AND SURROUNDING AREAS TO CLIMB INTO THE MID 50S DESPITE THE
MUCH COLDER AIRMASS...BUT STILL EXPECT LOWS WELL INTO THE 30S BY
TUESDAY NIGHT AS THE COLD AIRMASS DEEPENS OVER THE AREA.

EXTENDED FORECAST STARTING WEDNESDAY AND INTO NEXT WEEKEND WILL BE
RELATIVELY QUIET AS FAR AS PRECIPITATION GOES WITH BELOW NORMAL
TEMPERATURES.  COOLER AIR WILL CONTINUE TO FILTER INTO THE REGION AS
THE GREAT LAKES RESIDES IN THE PERSISTENT LONGWAVE TROUGHING.  WHILE
THERE WILL BE SLIGHT PRECIPITATION CHANCES WHILE THE REGION RESIDES
IN THE TROUGH...THE CAVEAT IS THE LACK OF MOISTURE THAT WILL BE
AVAILABLE.  RIDGING DOES NOT LOOK TO START BUILDING INTO THE WESTERN
GREAT LAKES REGION UNTIL THE END OF THE FORECAST PERIOD.

MARINE...

EAST FLOW WILL GRADUALLY BECOME SOUTHEAST TONIGHT AS DEEPENING LOW
PRESSURE PUSHES A WARM FRONT THROUGH THE AREA. DURING THIS TIME
FRAME...EXPECT STEADILY INCREASING WIND SPEEDS WHICH WILL ALLOW
WAVES TO BUILD. AS THIS LOW PASSES INTO THE NORTHERN GREAT LAKES
MONDAY...WINDS REMAIN GUSTY AND VEER TO THE SOUTH AND THEN SOUTHWEST
AS A COLD FRONT SWEEPS AROUND THE BASE OF THE EXITING LOW PRESSURE.
SMALL CRAFT ADVISORIES WILL CONTINUE INTO MONDAY. WHILE A FEW GUSTS
MAY APPROACH GALE FORCE...THE MARINE LAYER LOOKS TO BE FAIRLY STABLE
WHICH WILL LIMIT THIS POTENTIAL. WINDS WILL SUBSIDE TO SOME EXTENT
FROM MONDAY NIGHT INTO TUESDAY AS THE LOW STALLS NEAR JAMES BAY AND
BEGINS TO SLOWLY WEAKEN.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR LHZ441>443.

     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 8 PM EDT MONDAY FOR
     LHZ421-422.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR LEZ444.

&&

$$

AVIATION.....SC
SHORT TERM...CB
LONG TERM....DG/SS
MARINE.......DG


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).



000
FXUS63 KDTX 192300
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
700 PM EDT SUN APR 19 2015


.AVIATION...

RAIN WILL CONTINUE EXPANDING ACROSS SE MI AND WILL OVERSPREAD THE
TERMINALS BY 00Z. EASTERLY WINDS HAVE BEEN SUSTAINING LOW LEVEL DRY
AIR WHICH IN TURN HAS HELD CEILINGS UP. A SUBSTANTIAL AMOUNT OF
MOISTURE ADVECTION DURING THE EVENING AND OVERNIGHT ALONG WITH
INCREASING INTENSITY OF RAINFALL WILL HOWEVER LEAD TO A STEADY
LOWERING TREND IN CEILINGS THIS EVENING. IFR CONDITIONS ARE EXPECT
TO DEVELOP EITHER LATE THIS EVENING OR EARLY IN THE OVERNIGHT
PERIOD. UPSTREAM OBSERVATIONS DO HOWEVER SUGGEST THERE IS LIKELY TO
BE A GOOD DEAL OF VARIABILITY IN CEILING HEIGHTS. THIS RAIN AND
MOISTURE THAT IS LIFTING ACROSS THE AREA IS ASSOCIATED WITH A LOW
PRESSURE SYSTEM OVER INDIANA. THIS LOW WILL LIFT ACROSS WESTERN
LOWER MI TONIGHT. EVEN WITH THE RAINFALL...THE SFC GRADIENT SHOULD
SUSTAIN SOME DEGREE OF GUSTINESS TO THE WINDS TONIGHT /POSSIBLY
TOPPING 20 KNOTS AT TIMES/. A WARM FRONT ASSOCIATED WITH THE SFC LOW
IS FORECAST TO LIFT NORTH ACROSS SE MI BETWEEN 09Z AND 12Z. THE
PASSAGE OF THIS FRONT WILL VEER WINDS TO THE SOUTH AND MAY ACTUALLY
LEAD TO SOME LIFTING OF CLOUD BASES AS THE WARM SECTOR NUDGES INTO
THE AREA.

FOR DTW...THE PEAK IN RAINFALL INTENSITY IS EXPECTED TO OCCUR
BETWEEN 02Z AND 05Z...WHERE SOME PERIODIC HEAVY RAINFALL IS
POSSIBLE. WHILE CEILING HEIGHTS WILL FLUCTUATE A GOOD DEAL...THE
OVERALL TREND HEADING INTO THE OVERNIGHT WILL BE FOR THE DEVELOPMENT
OF IFR CONDITIONS.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS AOB 5KFT TONIGHT AND MONDAY.

* LOW IN THUNDERSTORMS TONIGHT AND MONDAY.

&&

.PREV DISCUSSION...ISSUED 356 PM EDT SUN APR 19 2015

SHORT TERM...TONIGHT

THE ARC OF SHOWER ACTIVITY FORCED ON AN INITIAL SURGE/GRADIENT OF
850-700MB MOISTURE HAS STRUGGLED FROM A VIGOR PERSPECTIVE DUE TO A
LACK OF INSTABILITY. WITH SHOWERS WORKING UP THE FRONTAL SLOPE AS IT
TRACKS NORTHWARD...EXPECT THE WEAK NATURE TO CONTINUE.

THE MAIN BAND OF SYNOPTIC FORCING AND WIDESPREAD RAIN ACTIVITY WILL
LIFT ACROSS THE OHIO AND MICHIGAN BORDER AROUND 21Z. REGIONAL MOSAIC
AS OF 19Z... SHOWS THE MIDLEVELS SATURATING SOUTH OF TOLEDO. REALLY
A TREMENDOUS AMOUNT OF SYNOPTIC SCALE SUPPORT FOR LIFT AND
PRECIPITATION GENERATION TONIGHT AS SOUTHEASTERN MICHIGAN REMAINS
FAVORABLY POSITIONED AHEAD OF A HIGH AMPLITUDE WARM SECTOR
STRUCTURE AND OPTIMAL WARM AIR ADVECTION. EVERYTHING APPEARS TO BE
LINING UP FROM A FORCING STANDPOINT FOR A FAVORABLE PERIOD OF
WIDESPREAD RAIN INCLUDING A POTENTIAL FOR HEAVY RAINFALL.
SPECIFICALLY...LARGE BULLSEYE OF 1000-500MB HEIGHT FALLS...LINKAGE
OF RIGHT NOSE OF LOW LEVEL JET AXIS WITH RIGHT ENTRANCE REGION
DYNAMICS ALOFT...AND A DIRECT HIT FROM A SECONDARY VORTICITY
MAXIMUM. NWP SUPPORTS THIS SECONDARY VORTICITY MAXIMUM BECOMING
ORGANIZED/STRENGTHENING NEAR LOUISVILLE NOW AND LIFTING INTO FAR
SOUTHEASTERN MICHIGAN BETWEEN 00-03Z. NAM REALLY BITES ON THIS
FEATURE SHOWING DEPICTIONS OF A PSEUDO SHARS TYPE RESPONSE AND
HIGH AMOUNTS OF 3HR QPF. BROAD NATIONAL MOSAIC OF REFLECTIVITY
ALONG WITH SATELLITE IMAGERY OF CLEARING/DESTABILIZING STRAIGHT
INTO CENTRAL KENTUCKY SUPPORTS THIS STRONG SOLUTION OF THE
SECONDARY VORTICITY MAXIMUM. THUS...THE EARLIER FORECAST OF
FORECASTING QPF AMOUNTS OF UPWARDS OF 1.00 INCH FOR FAR
SOUTHEASTERN MICHIGAN INCLUDING THE DETROIT METRO APPEARS
REASONABLE. THERE AT LEAST REMAINS SOME POTENTIAL THAT THIS DRY
AIR/SLOT COULD WORK NORTHWARD AT A CRITICAL TRAJECTORY AND CAUSE
HEAVY PRECIPITATION TO DEFLECT AWAY FROM THE CWA. CONFIDENCE IN
PROJECTING THAT OUT IS LOW. WHILE FORECASTED QPF AMOUNTS ARE
RELATIVELY HIGH FROM AN EVENT STANDPOINT...THE STEADY NORTHWARD
PROGRESSION OF SHOWERS/EMBEDDED THUNDER WILL LIMIT THE CONCERN FOR
FLOODING.

LONG TERM...

STRONG LOW PRESSURE WILL CONTINUE TO DEEPEN AS IT LIFTS NORTHWARD
THROUGH NORTHERN LOWER MICHIGAN INTO ONTARIO ON MONDAY. MODELS HAVE
TRENDED SLIGHTLY SLOWLY AND FURTHER WEST WITH THE TRACK OF THIS
SYSTEM...AND THIS WILL MOSTLY LIKELY HAVE SOME NOTABLE IMPLICATIONS
TO THE GOING FORECAST. AS SUCH...HAVE MADE A FEW ADJUSTMENTS FOR
THIS PACKAGE.

THE "NEW" CONSENSUS TRACK FORECAST WILL ESSENTIALLY DELAY THE COLD
FRONTAL PASSAGE THROUGH THE AREA UNTIL LATE AFTERNOON AND ALLOW FOR
TEMPERATURES TO CLIMB WELL INTO THE 60S OVER A GOOD PORTION OF THE
AREA. THIS...IN TURN...WILL ALLOW FOR SOME DESTABILIZATION AS SBCAPE
VALUES CLIMB TO AROUND 500 J/KG BY AFTERNOON. THIS SHOULD ALLOW FOR
MORE VIGOROUS CONVECTION ALONG THE COLD FRONT WITH THE POTENTIAL FOR
HAIL INCREASING AS FREEZING LEVELS DROP BELOW 7000-8000 FEET AS COLD
AIR WRAP AROUND THE UPPER CIRCULATION.

IN ADDITION...THIS ACTIVITY WILL LIKELY PRODUCE SOME GUSTY WINDS AS
DEEP SWATH OF 35 TO 40 KT SOUTHWEST FLOW OVERSPREADS THE AREA. EVEN
OUTSIDE OF STORMS...WIND GUSTS WILL LIKELY REACH 35 MPH AT TIMES BY
AFTERNOON AND HAVE UPPED THE OVERALL FORECAST WINDS A FAIR AMOUNT.
WHILE WIDESPREAD STRONG STORMS ARE PROBABLY NOT TOO LIKELY...A FEW
WILL CERTAINLY BECOME A BIT ROBUST AS FORCING ALONG THE COLD FRONT
HELPS FOCUS THE MARGINAL INSTABILITY THAT IS ABLE TO BUILD OVER
PARTS OF THE AREA.

CONDITIONS WILL QUIET FROM MID EVENING INTO TUESDAY AS THE LOW LIFTS
TO NEAR JAMES BAY AND STALLS. THAT SAID...CONDITIONS WILL REMAIN
RATHER UNSETTLED INTO THE TUESDAY AND TUESDAY NIGHT PERIOD AS THIS
LOW ONLY GRADUALLY WEAKENS. EXPECT COOLER TEMPERATURES AND CONTINUE
GUSTY WINDS WITH SCATTERED RAIN SHOWERS DOTTING THE REGION...MAINLY
IN THE TUESDAY AFTERNOON PERIOD DURING THE DIURNAL TEMPERATURE AND
INSTABILITY MAX. DOWNSLOPING WEST/SOUTHWEST FLOW SHOULD ALLOW METRO
DETROIT AND SURROUNDING AREAS TO CLIMB INTO THE MID 50S DESPITE THE
MUCH COLDER AIRMASS...BUT STILL EXPECT LOWS WELL INTO THE 30S BY
TUESDAY NIGHT AS THE COLD AIRMASS DEEPENS OVER THE AREA.

EXTENDED FORECAST STARTING WEDNESDAY AND INTO NEXT WEEKEND WILL BE
RELATIVELY QUIET AS FAR AS PRECIPITATION GOES WITH BELOW NORMAL
TEMPERATURES.  COOLER AIR WILL CONTINUE TO FILTER INTO THE REGION AS
THE GREAT LAKES RESIDES IN THE PERSISTENT LONGWAVE TROUGHING.  WHILE
THERE WILL BE SLIGHT PRECIPITATION CHANCES WHILE THE REGION RESIDES
IN THE TROUGH...THE CAVEAT IS THE LACK OF MOISTURE THAT WILL BE
AVAILABLE.  RIDGING DOES NOT LOOK TO START BUILDING INTO THE WESTERN
GREAT LAKES REGION UNTIL THE END OF THE FORECAST PERIOD.

MARINE...

EAST FLOW WILL GRADUALLY BECOME SOUTHEAST TONIGHT AS DEEPENING LOW
PRESSURE PUSHES A WARM FRONT THROUGH THE AREA. DURING THIS TIME
FRAME...EXPECT STEADILY INCREASING WIND SPEEDS WHICH WILL ALLOW
WAVES TO BUILD. AS THIS LOW PASSES INTO THE NORTHERN GREAT LAKES
MONDAY...WINDS REMAIN GUSTY AND VEER TO THE SOUTH AND THEN SOUTHWEST
AS A COLD FRONT SWEEPS AROUND THE BASE OF THE EXITING LOW PRESSURE.
SMALL CRAFT ADVISORIES WILL CONTINUE INTO MONDAY. WHILE A FEW GUSTS
MAY APPROACH GALE FORCE...THE MARINE LAYER LOOKS TO BE FAIRLY STABLE
WHICH WILL LIMIT THIS POTENTIAL. WINDS WILL SUBSIDE TO SOME EXTENT
FROM MONDAY NIGHT INTO TUESDAY AS THE LOW STALLS NEAR JAMES BAY AND
BEGINS TO SLOWLY WEAKEN.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR LHZ441>443.

     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 8 PM EDT MONDAY FOR
     LHZ421-422.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR LEZ444.

&&

$$

AVIATION.....SC
SHORT TERM...CB
LONG TERM....DG/SS
MARINE.......DG


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).




000
FXUS63 KMQT 192030
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
430 PM EDT SUN APR 19 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

TWO UPPER LEVEL WAVES WILL BE AFFECTING THE REGION TONIGHT BEFORE
MERGING TOGETHER INTO A LARGE UPPER TROUGH THAT WILL PERSIST OVER
EASTERN CANADA AND THE GREAT LAKES REGION FOR MUCH OF THE UPCOMING
WORK WEEK. THIS WILL LEAD TO A TRANSITION FROM THE ABOVE NORMAL
TEMPERATURES AND DRY CONDITIONS TO A PERIOD OF BELOW NORMAL
TEMPERATURES AND PERIODS OF RAIN/SNOW SHOWERS.

THE FIRST WAVE OF PRECIPITATION JUST BRUSHED THE WESTERN U.P.
EARLIER TODAY...ASSOCIATED WITH A SHORTWAVE AND MID LEVEL WARM AIR
ADVECTION. MUCH OF THAT PRECIPITATION HAS SHIFTED OFF TO THE NORTH
OF THE MINNESOTA ARROWHEAD...BUT LINGERING MID LEVEL MOISTURE AND
BROAD BUT WEAK WARM AIR ADVECTION HAS PRODUCED A FEW RAIN SHOWERS
OVER WESTERN/CENTRAL UPPER MICHIGAN LATE THIS MORNING AND THROUGH
THE EARLY AFTERNOON. WHILE THE 12Z KGRB SOUNDING STILL SHOWS SOME
DRY AIR BELOW THE CLOUD BASES...IT HAS ERODED SIGNIFICANTLY SINCE
THE 00Z KGRB SOUNDING AND ALLOWED SOME OF THAT RAIN TO REACH THE
GROUND. THAT DISTURBANCE PRODUCING THE SHOWERS WILL SHIFT TO THE
NORTH OVER THE NEXT COUPLE OF HOURS AND SHIFT THE FOCUS TO THE RAIN
CURRENTLY TO THE WEST AND SOUTH OF THE CWA.

WITH THE LATEST TRENDS IN THE MODELS DELAYING THE ARRIVAL OF THE
PRECIPITATION FROM THE SOUTH (ASSOCIATED WITH THE SOUTHERN WAVE AND
SURFACE LOW QUICKLY LIFTING NORTH ACROSS THE SOO MONDAY MORNING)
UNTIL LATE IN THE EVENING AND MORE DURING THE OVERNIGHT HOURS...HAVE
CONTINUED TO SHOW THAT SLOWING TREND IN THE POPS FOR THIS EVENING.
IN FACT...OTHER THAN SOME CHANCES OVER THE FAR WEST THIS
EVENING...HAVE REMOVED THE POPS OVER THE CENTRAL EAST BETWEEN THE
23Z-03Z PERIOD AND THEN RAMPED THEM UP AS THAT WAVE AND LOW ARRIVES
FROM THE SOUTH. THAT PRECIPITATION WILL THEN QUICKLY SHIFT NORTH
ACROSS THE AREA AND EXPECT MUCH OF THE CENTRAL/EASTERN U.P. TO SEE
AT LEAST 0.3 INCH OF RAIN. THERE WILL BE SOME HIGHER
AMOUNTS...LIKELY 0.5-0.6IN WHERE THE DEFORMATION ZONE OCCURS ON THE
NORTHWEST SIDE OF THE SURFACE LOW (SOMEWHERE AROUND THE CENTRAL OR
WEST-CENTRAL U.P.). FARTHER TO THE WEST...EXPECT THE ONGOING RAIN
SHOWERS STRETCHING FROM THE ARROWHEAD OF MINNESOTA THROUGH WESTERN
WISCONSIN AND INTO NORTHEAST IOWA TO SLOWLY SHIFT EAST INTO FAR
WESTERN UPPER MICHIGAN THIS EVENING...AS THE 850-700MB TROUGH SLOWLY
WORKS ITS WAY TO THE EAST. THIS PRECIPITATION WILL MERGE WITH THE
WAVE COMING UP FROM THE SOUTH AND FILL IN THE EXPECTED GAP OVER THE
KEWEENAW OVERNIGHT.

WITH THE SHORTWAVE AND SURFACE LOW QUICKLY MOVING TO THE NORTH ON
MONDAY...EXPECT THE PRECIPITATION TO DIMINISH FROM SOUTHWEST TO
NORTHEAST THROUGH THE DAY (AIDED BY THE MID LEVEL DRY SLOT THAT
SLOWLY MOVES INTO THE AREA). WHILE MUCH OF THIS PRECIP WILL OCCUR AS
RAIN...THE COLD AIR GRADUALLY MOVING INTO THE WESTERN CWA LATE
TONIGHT AND MONDAY COULD CAUSE IT TO MIXING WITH OR EVEN CHANGING
OVER TO SNOW OVER THE WEST AND POSSIBLY EVEN NORTH CENTRAL. THOUGHT
THAT THE WETBULB ZERO HAD A GOOD HANDLE ON THE WEST TO EAST
TRANSITION OF THAT MIX WITH SNOW...BUT DO HAVE A CONCERN ON THE
AMOUNT OF ICE CRYSTALS THAT WILL BE PRESENT ON MONDAY. MODELS
SHOWING THAT THE DEEPER MOISTURE REALLY BEGINS TO PULL OUT THROUGH
THE DAY AS THE MID LEVEL DRY SLOT MOVES BEHIND THE 850/700MB TROUGH.
THAT CONCERN WARRANTS KEEPING RAIN POTENTIAL IN THE FORECAST EVEN
THOUGH SOME AREAS THE WETBULB ZERO VALUES WOULD SUPPORT ALL SNOW.
ONE FINAL NOTE...THE HIGHER RESOLUTION 12Z MODELS ARE SHOWING A
SLOWER DEPARTURE TO THE PRECIP ON MONDAY...SO DID TREND SLIGHTLY
SLOWER WITH THIS FORECAST AND IT MAY NEED TO BE DELAYED FURTHER WITH
THE UPCOMING SHIFT. THAT SLOWER DEPARTURE AND INDICATIONS OF COLDER
AIR...COULD LEAD TO SOME MINOR SNOW ACCUMULATIONS ON GRASSY SURFACES
OVER THE WEST AROUND MID MORNING.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 423 PM EDT SUN APR 19 2015

THE PATTERN WILL BE DOMINATED BY A MID/UPPER LEVEL LOW MOVING SLOWLY
THROUGH THE GREAT LAKES BRINGING UNSETTLED WEATHER ALONG WITH BELOW
NORMAL TEMPERATURES. THE LOW SHOULD FINALLY SHIFT TOWARD ERN CANADA
AND NEW ENGLAND BY THE WEEKEND LEAVING NW FLOW IN PLACE WITH
CONTINUED BELOW NORMAL TEMPERATURES.

MON NIGHT THROUGH TUE NIGHT...MODELS SUGGEST THAT THE MID LEVEL LOW
WILL SLOWLY WOBBLE INTO THE NRN GREAT LAKES. WITH THE COMBINATION OF
DEEP MOISTURE AND WEAK SHORTWAVES NEAR THE LOW...EXPECT INCREASING
PCPN CHANCES AS MAINLY SNOW...PER FCST SOUNDINGS. THERE MAY BE SOME
ADDITIONAL LAKE ENHANCED (850 MB TEMPS DROP TO AROUND -8C) INTO THE
HIGHER TERRAIN OVER THE WEST WITH UPSLOPE WNW FLOW. SNOW
ACCUMULATIONS OF A FEW INCHES ARE POSSIBLE...MAINLY ON GRASSY
SURFACES. HOWEVER...WITH THE ARRIVAL OF THE SNOW OVERNIGHT SOME
ACCUMULATION ON ROADS MAY ALSO CREATE HAZARDOUS TRAVEL TUE MORNING.
DAYTIME HEATING TUE MAY ENHANCE THE PCPN OVER INLAND AREAS WITH STEEP
SFC-700MB LAPSE RATES DEVELOPING. WITH TEMPS CLIMBING TO AROUND
40F...THE PCPN MAY MIX WITH RAIN OVER THE SE HALF OF THE CWA. 12Z NAM
FCST WET-BULB ZERO HEIGHTS WERE USED TO DELINEATE PCPN TYPE. ANOTHER
INCH OR TWO OF SNOW WILL BE POSSIBLE MAINLY OVER THE NW WIND
SNOWBELTS IN THE WEST TUE NIGHT AS 850 MB TEMPS DROP TO AROUND -12C
WHILE THE DEEP MOISTURE AND LOW LEVEL CYCLONIC FLOW REMAIN IN PLACE.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN SOUTH DURING
PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE CONTRIBUTION AS 850
MB TEMPS RANGE FROM -10C TO -13C...THE BEST COVERAGE DURING THE
DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM LAKE SUPERIOR WHERE
HEATING WILL BE STRONGEST. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW
NORMAL...IN THE MID 30S TO LOWER 40S...WARMEST S CNTRL.

FRI-SUN...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH ONLY MINIMAL PCPN CHANCES.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 133 PM EDT SUN APR 19 2015

VFR CONDITIONS WILL CONTINUE INTO THE EVENING HOURS...BEFORE TWO
SEPARATE FEATURES BRING WIDESPREAD RAIN AND RAPIDLY LOWERING
CEILINGS TO THE AREA LATE THIS EVENING INTO MONDAY. LINGERING LOW
LEVEL DRY AIR WILL CONTINUE TO LEAD TO MID CLOUDS AND MAYBE AN
ISOLATED SHOWERS THIS AFTERNOON. THE MAIN QUESTION MARK FOR THE
FORECAST IS THE TIMING OF THE RAIN AND IN TURN LOWER
CEILINGS/VISIBILITIES.

AT KIWD...MODELS HAVE BEEN TRENDING TOWARDS KEEPING THE HEAVIEST
PRECIPITATION OFF TO THE WEST OF THE SITE THROUGH THE EVENING.
CONFIDENCE IS LOW ON THE EASTERN EDGE OF THE PRECIPITATION...BUT
HAVE KEPT THE IDEA OF THE SHOWERS BRUSHING THE SITE BY MID EVENING
AND THEN SPREADING EAST THROUGH THE SITE TONIGHT. EXPECT THE LOW
LEVEL WINDS TO TURN OFF LAKE SUPERIOR AND WITH RAIN OVER THE COLD
WATER WOULD EXPECT LOW CLOUDS AND FOG TO AFFECT THE SITE OVERNIGHT.
THE RAIN COULD MIX WITH OR CHANGE TO SNOW TOMORROW MORNING BEFORE
ENDING TOWARDS THE END OF THE TAF PERIOD.

AT KCMX/KSAW...BOTH SITES STAY IN THE DRIER AIR LONGER BEFORE THE
PRECIPITATION QUICKLY DETERIORATES BOTH CEILINGS AND VISIBILITIES
(AFTER MIDNIGHT AND TOWARDS 09Z). WITH BOTH SITES EXPERIENCING
FAVORABLE WINDS OFF LAKE SUPERIOR LATE TONIGHT INTO MONDAY...EXPECT
LIFR CEILINGS AND SOME FOG TO OCCUR. THOSE IFR/LIFR CEILINGS WILL
REMAIN THROUGH MUCH OF MONDAY MORNING.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 258 PM EDT SUN APR 19 2015

SOUTHEASTERLY WINDS UP TO 25-30KTS ARE OCCURRING OVER NORTHEAST
LAKE SUPERIOR...WITH A FEW GUSTS NEARING GALE FORCE VALUES AT THE
HIGHER PLATFORMS (SHIP OBS AND PILM4). AS A LOW IN SOUTHERN ILLINOIS
LIFTS NORTH TONIGHT AND THROUGH THE SOO ON MONDAY MORNING...WINDS
WILL WEAKEN THIS EVENING AND THEN BACK TO THE WEST-NORTHWEST ON
MONDAY. WITH THE LOW BECOMING STATIONARY JUST TO THE SOUTHWEST OF
JAMES BAY MONDAY NIGHT THROUGH WEDNESDAY...PERSISTENT NORTHWESTERLY
WINDS OF 20-30KTS ARE EXPECTED. ALTHOUGH THE LOW WILL WEAKEN AND
MOVE EAST ACROSS QUEBEC WEDNESDAY NIGHT INTO THURSDAY...THE
NORTHWEST WINDS UP TO 25KTS WILL PERSIST AS A RIDGE MOVES INTO THE
NORTHERN PLAINS.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...SRF
LONG TERM...JLB
AVIATION...SRF
MARINE...SRF




000
FXUS63 KMQT 192030
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
430 PM EDT SUN APR 19 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

TWO UPPER LEVEL WAVES WILL BE AFFECTING THE REGION TONIGHT BEFORE
MERGING TOGETHER INTO A LARGE UPPER TROUGH THAT WILL PERSIST OVER
EASTERN CANADA AND THE GREAT LAKES REGION FOR MUCH OF THE UPCOMING
WORK WEEK. THIS WILL LEAD TO A TRANSITION FROM THE ABOVE NORMAL
TEMPERATURES AND DRY CONDITIONS TO A PERIOD OF BELOW NORMAL
TEMPERATURES AND PERIODS OF RAIN/SNOW SHOWERS.

THE FIRST WAVE OF PRECIPITATION JUST BRUSHED THE WESTERN U.P.
EARLIER TODAY...ASSOCIATED WITH A SHORTWAVE AND MID LEVEL WARM AIR
ADVECTION. MUCH OF THAT PRECIPITATION HAS SHIFTED OFF TO THE NORTH
OF THE MINNESOTA ARROWHEAD...BUT LINGERING MID LEVEL MOISTURE AND
BROAD BUT WEAK WARM AIR ADVECTION HAS PRODUCED A FEW RAIN SHOWERS
OVER WESTERN/CENTRAL UPPER MICHIGAN LATE THIS MORNING AND THROUGH
THE EARLY AFTERNOON. WHILE THE 12Z KGRB SOUNDING STILL SHOWS SOME
DRY AIR BELOW THE CLOUD BASES...IT HAS ERODED SIGNIFICANTLY SINCE
THE 00Z KGRB SOUNDING AND ALLOWED SOME OF THAT RAIN TO REACH THE
GROUND. THAT DISTURBANCE PRODUCING THE SHOWERS WILL SHIFT TO THE
NORTH OVER THE NEXT COUPLE OF HOURS AND SHIFT THE FOCUS TO THE RAIN
CURRENTLY TO THE WEST AND SOUTH OF THE CWA.

WITH THE LATEST TRENDS IN THE MODELS DELAYING THE ARRIVAL OF THE
PRECIPITATION FROM THE SOUTH (ASSOCIATED WITH THE SOUTHERN WAVE AND
SURFACE LOW QUICKLY LIFTING NORTH ACROSS THE SOO MONDAY MORNING)
UNTIL LATE IN THE EVENING AND MORE DURING THE OVERNIGHT HOURS...HAVE
CONTINUED TO SHOW THAT SLOWING TREND IN THE POPS FOR THIS EVENING.
IN FACT...OTHER THAN SOME CHANCES OVER THE FAR WEST THIS
EVENING...HAVE REMOVED THE POPS OVER THE CENTRAL EAST BETWEEN THE
23Z-03Z PERIOD AND THEN RAMPED THEM UP AS THAT WAVE AND LOW ARRIVES
FROM THE SOUTH. THAT PRECIPITATION WILL THEN QUICKLY SHIFT NORTH
ACROSS THE AREA AND EXPECT MUCH OF THE CENTRAL/EASTERN U.P. TO SEE
AT LEAST 0.3 INCH OF RAIN. THERE WILL BE SOME HIGHER
AMOUNTS...LIKELY 0.5-0.6IN WHERE THE DEFORMATION ZONE OCCURS ON THE
NORTHWEST SIDE OF THE SURFACE LOW (SOMEWHERE AROUND THE CENTRAL OR
WEST-CENTRAL U.P.). FARTHER TO THE WEST...EXPECT THE ONGOING RAIN
SHOWERS STRETCHING FROM THE ARROWHEAD OF MINNESOTA THROUGH WESTERN
WISCONSIN AND INTO NORTHEAST IOWA TO SLOWLY SHIFT EAST INTO FAR
WESTERN UPPER MICHIGAN THIS EVENING...AS THE 850-700MB TROUGH SLOWLY
WORKS ITS WAY TO THE EAST. THIS PRECIPITATION WILL MERGE WITH THE
WAVE COMING UP FROM THE SOUTH AND FILL IN THE EXPECTED GAP OVER THE
KEWEENAW OVERNIGHT.

WITH THE SHORTWAVE AND SURFACE LOW QUICKLY MOVING TO THE NORTH ON
MONDAY...EXPECT THE PRECIPITATION TO DIMINISH FROM SOUTHWEST TO
NORTHEAST THROUGH THE DAY (AIDED BY THE MID LEVEL DRY SLOT THAT
SLOWLY MOVES INTO THE AREA). WHILE MUCH OF THIS PRECIP WILL OCCUR AS
RAIN...THE COLD AIR GRADUALLY MOVING INTO THE WESTERN CWA LATE
TONIGHT AND MONDAY COULD CAUSE IT TO MIXING WITH OR EVEN CHANGING
OVER TO SNOW OVER THE WEST AND POSSIBLY EVEN NORTH CENTRAL. THOUGHT
THAT THE WETBULB ZERO HAD A GOOD HANDLE ON THE WEST TO EAST
TRANSITION OF THAT MIX WITH SNOW...BUT DO HAVE A CONCERN ON THE
AMOUNT OF ICE CRYSTALS THAT WILL BE PRESENT ON MONDAY. MODELS
SHOWING THAT THE DEEPER MOISTURE REALLY BEGINS TO PULL OUT THROUGH
THE DAY AS THE MID LEVEL DRY SLOT MOVES BEHIND THE 850/700MB TROUGH.
THAT CONCERN WARRANTS KEEPING RAIN POTENTIAL IN THE FORECAST EVEN
THOUGH SOME AREAS THE WETBULB ZERO VALUES WOULD SUPPORT ALL SNOW.
ONE FINAL NOTE...THE HIGHER RESOLUTION 12Z MODELS ARE SHOWING A
SLOWER DEPARTURE TO THE PRECIP ON MONDAY...SO DID TREND SLIGHTLY
SLOWER WITH THIS FORECAST AND IT MAY NEED TO BE DELAYED FURTHER WITH
THE UPCOMING SHIFT. THAT SLOWER DEPARTURE AND INDICATIONS OF COLDER
AIR...COULD LEAD TO SOME MINOR SNOW ACCUMULATIONS ON GRASSY SURFACES
OVER THE WEST AROUND MID MORNING.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 423 PM EDT SUN APR 19 2015

THE PATTERN WILL BE DOMINATED BY A MID/UPPER LEVEL LOW MOVING SLOWLY
THROUGH THE GREAT LAKES BRINGING UNSETTLED WEATHER ALONG WITH BELOW
NORMAL TEMPERATURES. THE LOW SHOULD FINALLY SHIFT TOWARD ERN CANADA
AND NEW ENGLAND BY THE WEEKEND LEAVING NW FLOW IN PLACE WITH
CONTINUED BELOW NORMAL TEMPERATURES.

MON NIGHT THROUGH TUE NIGHT...MODELS SUGGEST THAT THE MID LEVEL LOW
WILL SLOWLY WOBBLE INTO THE NRN GREAT LAKES. WITH THE COMBINATION OF
DEEP MOISTURE AND WEAK SHORTWAVES NEAR THE LOW...EXPECT INCREASING
PCPN CHANCES AS MAINLY SNOW...PER FCST SOUNDINGS. THERE MAY BE SOME
ADDITIONAL LAKE ENHANCED (850 MB TEMPS DROP TO AROUND -8C) INTO THE
HIGHER TERRAIN OVER THE WEST WITH UPSLOPE WNW FLOW. SNOW
ACCUMULATIONS OF A FEW INCHES ARE POSSIBLE...MAINLY ON GRASSY
SURFACES. HOWEVER...WITH THE ARRIVAL OF THE SNOW OVERNIGHT SOME
ACCUMULATION ON ROADS MAY ALSO CREATE HAZARDOUS TRAVEL TUE MORNING.
DAYTIME HEATING TUE MAY ENHANCE THE PCPN OVER INLAND AREAS WITH STEEP
SFC-700MB LAPSE RATES DEVELOPING. WITH TEMPS CLIMBING TO AROUND
40F...THE PCPN MAY MIX WITH RAIN OVER THE SE HALF OF THE CWA. 12Z NAM
FCST WET-BULB ZERO HEIGHTS WERE USED TO DELINEATE PCPN TYPE. ANOTHER
INCH OR TWO OF SNOW WILL BE POSSIBLE MAINLY OVER THE NW WIND
SNOWBELTS IN THE WEST TUE NIGHT AS 850 MB TEMPS DROP TO AROUND -12C
WHILE THE DEEP MOISTURE AND LOW LEVEL CYCLONIC FLOW REMAIN IN PLACE.

WED-THU...THE LARGE COLD MID-LEVEL LOW WILL ONLY SLOWLY SHIFT TO THE
ESE TO THE ERN LAKES BY LATE THU. COLD AIR ALOFT/SPRING DAYTIME
HEATING AND POTENTIAL OF SHORTWAVES ROTATING THROUGH THE AREA WITHIN
THE LARGE MID-LEVEL LOW CIRCULATION FAVORS AT LEAST SCT SHOWERY
PCPN... MOSTLY AS SNOW BUT POSSIBLY MIXING WITH RAIN SOUTH DURING
PEAK HEATING. ALTHOUGH THERE WILL BE SOME LAKE CONTRIBUTION AS 850
MB TEMPS RANGE FROM -10C TO -13C...THE BEST COVERAGE DURING THE
DAYTIME SHOULD BE IN THE AFTERNOON INLAND FROM LAKE SUPERIOR WHERE
HEATING WILL BE STRONGEST. HIGH TEMPS BOTH DAYS SHOULD BE WELL BELOW
NORMAL...IN THE MID 30S TO LOWER 40S...WARMEST S CNTRL.

FRI-SUN...FCST UNCERTAINTY IS GREATER AS THE GFS/GEFS/GEM MAINTAIN
TROUGHING INTO NRN ONTARIO AND THE NRN LAKES THROUGH THE WEEKEND
WHILE THE ECMWF BRINGS A RIDGE TOWARD THE WRN LAKES WITH DRIER AND
WARMER CONDITIONS. WITH EITHER SCENARIO...TEMPS ARE EXPECTED TO
REMAIN BELOW NORMAL WITH ONLY MINIMAL PCPN CHANCES.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 133 PM EDT SUN APR 19 2015

VFR CONDITIONS WILL CONTINUE INTO THE EVENING HOURS...BEFORE TWO
SEPARATE FEATURES BRING WIDESPREAD RAIN AND RAPIDLY LOWERING
CEILINGS TO THE AREA LATE THIS EVENING INTO MONDAY. LINGERING LOW
LEVEL DRY AIR WILL CONTINUE TO LEAD TO MID CLOUDS AND MAYBE AN
ISOLATED SHOWERS THIS AFTERNOON. THE MAIN QUESTION MARK FOR THE
FORECAST IS THE TIMING OF THE RAIN AND IN TURN LOWER
CEILINGS/VISIBILITIES.

AT KIWD...MODELS HAVE BEEN TRENDING TOWARDS KEEPING THE HEAVIEST
PRECIPITATION OFF TO THE WEST OF THE SITE THROUGH THE EVENING.
CONFIDENCE IS LOW ON THE EASTERN EDGE OF THE PRECIPITATION...BUT
HAVE KEPT THE IDEA OF THE SHOWERS BRUSHING THE SITE BY MID EVENING
AND THEN SPREADING EAST THROUGH THE SITE TONIGHT. EXPECT THE LOW
LEVEL WINDS TO TURN OFF LAKE SUPERIOR AND WITH RAIN OVER THE COLD
WATER WOULD EXPECT LOW CLOUDS AND FOG TO AFFECT THE SITE OVERNIGHT.
THE RAIN COULD MIX WITH OR CHANGE TO SNOW TOMORROW MORNING BEFORE
ENDING TOWARDS THE END OF THE TAF PERIOD.

AT KCMX/KSAW...BOTH SITES STAY IN THE DRIER AIR LONGER BEFORE THE
PRECIPITATION QUICKLY DETERIORATES BOTH CEILINGS AND VISIBILITIES
(AFTER MIDNIGHT AND TOWARDS 09Z). WITH BOTH SITES EXPERIENCING
FAVORABLE WINDS OFF LAKE SUPERIOR LATE TONIGHT INTO MONDAY...EXPECT
LIFR CEILINGS AND SOME FOG TO OCCUR. THOSE IFR/LIFR CEILINGS WILL
REMAIN THROUGH MUCH OF MONDAY MORNING.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 258 PM EDT SUN APR 19 2015

SOUTHEASTERLY WINDS UP TO 25-30KTS ARE OCCURRING OVER NORTHEAST
LAKE SUPERIOR...WITH A FEW GUSTS NEARING GALE FORCE VALUES AT THE
HIGHER PLATFORMS (SHIP OBS AND PILM4). AS A LOW IN SOUTHERN ILLINOIS
LIFTS NORTH TONIGHT AND THROUGH THE SOO ON MONDAY MORNING...WINDS
WILL WEAKEN THIS EVENING AND THEN BACK TO THE WEST-NORTHWEST ON
MONDAY. WITH THE LOW BECOMING STATIONARY JUST TO THE SOUTHWEST OF
JAMES BAY MONDAY NIGHT THROUGH WEDNESDAY...PERSISTENT NORTHWESTERLY
WINDS OF 20-30KTS ARE EXPECTED. ALTHOUGH THE LOW WILL WEAKEN AND
MOVE EAST ACROSS QUEBEC WEDNESDAY NIGHT INTO THURSDAY...THE
NORTHWEST WINDS UP TO 25KTS WILL PERSIST AS A RIDGE MOVES INTO THE
NORTHERN PLAINS.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...SRF
LONG TERM...JLB
AVIATION...SRF
MARINE...SRF



000
FXUS63 KAPX 192004
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
404 PM EDT SUN APR 19 2015

.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 402 PM EDT SUN APR 19 2015

HIGH IMPACT WEATHER: MINIMAL

FORECAST CHALLENGE: TIMING OF THE RAIN TONIGHT.

OVERVIEW...WHILE THE MOISTURE HAS BEEN INCREASING ALONG THE LAKE
HURON SHORE AND INLAND OF NE LOWER, NW LOWER HAS BEEN DRYING OUT
WITH A GOOD PORTION OF THE AREA WEST OF I-75 HAVING FALLEN BELOW
25%. IN E UPPER, THE RH HAS BEEN BETWEEN 40% AND 45%. WHAT THIS IS
DOING IS DELAYING THE RAIN SHIELD`S TRAVEL NORTH, WHICH HAD JUST
MADE IT TO THE MICHIGAN/INDIANA BORDER AROUND 19Z. USING THE TIMING
TOOL ON AWIPS, IT LOOKS LIKE THE RAIN SHOULD GET TO THE M-55
CORRIDOR AROUND 23Z, M-72 AROUND 00Z, M-32 AROUND 01Z, AND THE
STRAIT BETWEEN 02Z AND 03Z.

DETAILS FOR TONIGHT...AS WAS MENTIONED, TRYING TO TIME THIS SYSTEM
WITH THE DRY AIR IN THE LOWER LEVELS IS MADDENING. THE QUESTION
ISN`T IF THE AIR WILL LEAVE, BUT WHEN AS THE SFC LOW WILL, AS IT
MOVES UP FROM THE MID-MISSISSIPPI VALLEY, OVERWHELM WITH DRY AIR
WITH ITS MOISTURE, AND ALLOW THE RAIN TO FALL ALL THE WAY TO THE
SFC. HOWEVER, ONCE THE RAIN STARTS, IT WILL FALL THROUGH THE NIGHT
AS THE SFC NORTH OVER THE WESTERN PART OF THE STATE BETWEEN 06Z AND
12Z. THIS SFC LOW AND ASSOCIATED 500 MB SHORTWAVE TROUGH AND 50 KNOT
SPEED MAX THAT MOVES OVER THE STATE, OVER THE WARM FRONT. WITH THE
PWAT AROUND 1.0" OVERNIGHT OVER THE FORECAST AREA, WILL EXPECT
THAT A DECENT STEADY RAIN WILL RESULT.

&&

.SHORT TERM...(MONDAY THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

...SHOWERY/COOL/UNSETTLED THROUGH MIDWEEK...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: WELL-DEFINED SPLIT FLOW PATTERN FROM THE
END OF LAST WEEK NOW CONSOLIDATING AS NORTHERN BRANCH SHORT WAVE
TROUGH DIGS SOUTHEAST FROM WESTERN CANADA AND SCOOPS UP PESKY
SOUTHERN BRANCH VORTEX THAT HAS BEEN SPINNING ACROSS THE GREAT
BASIN/SOUTHERN ROCKIES SINCE THE MIDDLE OF LAST WEEK.  POSITIVE
PACIFIC TELECONNECTIONS LEADING TO A MORE AMPLIFIED PATTERN (BIG
TROUGH EAST OF THE DATELINE WITH +PNA RIDGING ALONG THE WEST COAST
OF NORTH AMERICA.  THIS CONSOLIDATING CENTRAL NORTH AMERICAN TROUGH
WILL BECOME THE PREDOMINANT WEATHER FEATURE THIS WEEK AS IT TAKES UP
RESIDENCE WITH REX BLOCKING ALONG THE WEST COAST...WITH AN UPPER LOW
EVENTUALLY PARKING ITSELF OVER THE GREAT LAKES BY MIDWEEK.

SOUTHERN BRANCH DISTURBANCE LOOKS TO COME OUT IN TWO PIECES
MONDAY...WHILE CLOSED CIRCULATION ALOFT DEVELOPS OVER NORTHWEST
ONTARIO/UPPER MIDWEST.  UPPER LOW THEN SETTLES OVER LAKE SUPERIOR
TUESDAY AND HANGS IN THROUGH MIDWEEK.  AT THE SURFACE...LEAD
SOUTHERN BRANCH SHORT WAVE TROUGH HAS AN ASSOCIATED SURFACE LOW OVER
THE MID MISSISSIPPI VALLEY THAT IS FORECAST TO DEEPEN AND LIFT NORTH
INTO LOWER MICHIGAN BY MONDAY MORNING...PROBABLY BELOW 990MB WHICH
IS PRETTY SIGNIFICANT BY MID-APRIL STANDARDS.  THIS LOW WILL PULL
COOLER AIR INTO MICHIGAN STARTING MONDAY NIGHT...CYCLONIC FLOW
LINGERS INTO MIDWEEK.

PRIMARY FORECAST CONCERNS: VARYING PRECIPITATION CHANCES THROUGH
MIDWEEK...AS WELL AS PRECIPITATION TYPE.

MONDAY...12Z SOUNDINGS AND GOES SOUNDER IMAGERY SHOWS A NICE SURGE
OF MOISTURE COMING UP ACROSS THE SOUTHEASTERN STATES (1.00-1.50 INCH
PRECIPITABLE WATER) WHICH IS PUSHING A LARGE ARE OF RAIN NORTHWARD
ACROSS THE OHIO VALLEY...AND EVENTUALLY INTO MICHIGAN TONIGHT/MONDAY
MORNING.  THIS WILL PUSH THROUGH THE FORECAST AREA MONDAY MORNING
(PERHAPS FAIRLY QUICKLY) WITH MID LEVEL DRYING (POSSIBLY TAPERING
OFF TO A PERIOD OF DRIZZLE).  SURFACE LOW TRACKS ACROSS NORTHERN
LOWER MONDAY MORNING...BEHIND THAT A LINGERING BAND OF DEFORMATION/
FRONTOGENETIC PRECIPITATION WILL ROTATE IN FROM THE WEST DURING THE
AFTERNOON HOURS.  IN ADDITION...COULD SEE SOME CONVECTIVE PRECIP
CLOSE TO THE SOUTHEAST PORTION OF THE FORECAST AREA DURING THE LATE
MORNING/AFTERNOON WITH SOME ELEVATED INSTABILITY (TQ INDICES
POTENTIALLY IN THE 16-20C RANGE NEAR LOW LEVEL THETA-E RIDGE) AND
SECOND PIECE OF SOUTHERN BRANCH ENERGY SWINGING NORTHEAST ACROSS THE
LOWER PENINSULA.  MORE LIKELY THIS ACTIVITY WOULD OCCUR ACROSS THE
THUMB INTO LAKE HURON...BUT MAY BE CLOSE.  WILL NOT TRY AND VARY
PRECIP PROBABILITIES IN THE FORECAST GRIDS TO ACCOUNT FOR TIMING OF
VARIOUS WAVES OF PRECIPITATION (AS IT WILL BE WRONG ANYHOW)...WITH A
GENERIC HIGH LIKELY/CATEGORICAL POP THROUGH THE DAY SUFFICIENT FOR
NOW. AS LONG AS INITIAL AREA OF RAIN SCOOTS NORTH QUICKLY MONDAY
MORNING... NOT EXPECT A LOT OF RAINFALL IN THE 12Z-00Z TIME FRAME
(UNLESS CONVECTION CAN CLIP FAR EASTERN ZONES DURING THE AFTERNOON)
WITH FORECAST 12H QPF UNDER 0.25 INCH THOUGH COULD BE HIGHER ACROSS
EASTERN UPPER/FAR NORTHEAST LOWER GIVEN THE ABOVE CAVEATS.  TRACK OF
THE LOW RIGHT ACROSS LOWER MICHIGAN WILL LEAD TO SOME TRICKY
TEMPERATURE FORECASTS...IN GENERAL COOLER WEST AND WARMER EAST WITH
FALLING TEMPERATURES DURING THE MID/LATE AFTERNOON AS WINDS SWITCH
AROUND TO A MORE WESTERLY COMPONENT.

WHAT REMAINS OF DEFORMATION PRECIP BAND EXPECTED TO LIFT NORTHEAST
ACROSS NORTHERN MICHIGAN MONDAY EVENING...AFTER THAT MAY BE ON THE
QUIET SIDE OVERNIGHT AND WILL CONFINE POPS TO THE EVENING HOURS.
PRECIP TYPE MAY BE IN QUESTION ACROSS EASTERN UPPER AS DEPTH OF
SURFACE BASED WARM LAYER SHRINKS.  AS NORTHERN BRANCH SHORT WAVE
TROUGHS START GETTING INVOLVED IN THE FORECAST SCENARIO CAN`T RULE
OUT SOME ADDITIONAL SHOWERS DEVELOPING OVERNIGHT INTO TUESDAY
MORNING BUT NOT CONVINCED THE PROBABILITY RISES TO A SUFFICIENT
LEVEL TO INCLUDE IN THE FORECAST...WILL LEAVE IT OUT AND MAINTAIN
CONTINUITY.

TUESDAY...DEEP LAYER CYCLONIC FLOW ACROSS THE UPPER LAKES SPELLS
UNSETTLED AND NOT WARM WEATHER FOR TUESDAY.  DEEP MOISTURE WILL
ROTATE AROUND THE SOUTH SIDE OF THE UPPER LOW...AND COOL
TEMPERATURES ALOFT (AT OR BELOW -30C/500MB) WILL ADD A DIURNAL
COMPONENT TO SUPPORT SHOWERS...AND GIVEN COOL TEMPERATURES PRECIP
COULD FALL AS RAIN/SNOW/GRAUPEL.  GUSTY SOUTHWEST WINDS (20-30MPH
GUSTS PROBABLE NORTHERN LOWER) WON`T MAKE IT FEEL ANY WARMER...WITH
AFTERNOON HIGHS AROUND 40-MID 40S (10-15 DEGREES BELOW NORMAL).
SHOWERS WILL CONTINUE INTO TUESDAY NIGHT...COVERAGE MAY DECREASE
WITH ON DOWNWARD SIDE OF DIURNAL HEATING CYCLE BUT THEY WILL STILL
BE AROUND.  COOLING TEMPERATURES ALSO WILL TREND PRECIPITATION TO
ALL SNOW SHOWERS TUESDAY EVENING.

WEDNESDAY...MORE OF THE SAME FOR WEDNESDAY WITH CONTINUED COOL
CYCLONIC FLOW AND VARIOUS DISTURBANCES ROTATING AROUND THE PARENT
VORTEX.  HIGH TEMPERATURES PROBABLY A FEW DEGREES COOLER WEDNESDAY
AFTERNOON...WITH MORE TEMPERATURES STUCK BELOW 40 DEGREES LIKELY.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

THE PERIOD PICKS UP JUST AS THE PREVIOUS LEFT OFF WITH UPPER LEVEL
TROUGHING OVERHEAD AND MULTIPLE WEAK WAVES ROTATING THROUGH THE BASE
OF THE TROUGH...BRINGING RAIN/SNOW SHOWER CHANCES WEDNESDAY NIGHT
AND INTO THE DAY THURSDAY. AS MENTIONED BY PRIOR SHIFT...THE
MOVEMENT OF THE OVERALL PATTERN LOOKS MINIMAL THROUGH THE WEEKEND
WITH TROUGHING CLOSE ENOUGH WHERE ANY SUBTLE WAVE COULD KICK OFF
ADDITIONAL SHOWER ACTIVITY. HAVE GONE AHEAD AND ADDED LOW END CHANCE
POPS FOR THURSDAY NIGHT (MAINLY DIRECTLY DOWNWIND OF LAKE MICHIGAN
AND FOR THE EASTERN U.P.)...BUT WILL KEEP A MAINLY DRY FORECAST FROM
FRIDAY THROUGH SUNDAY AS THE MAJORITY OF THE TIME LOOKS TO REMAIN
PRECIPITATION FREE.

NO DOUBT THE OVERALL PATTERN WILL BE A RATHER CHILLY ONE...WITH H8
TEMPS APPROACHING -8C THROUGHOUT THE PERIOD. A BLENDED MODEL
GUIDANCE APPROACH WOULD SUGGEST HIGH TEMPERATURES STUCK IN THE UPPER
30S AND 40S (A SOLID 10-15 DEGREES BELOW NORMAL) AND LOWS MAINLY IN
THE 20S TO LOWER 30S.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 142 PM EDT SUN APR 19 2015

MOISTURE HAS BEEN SLOW TO MOVE INTO THE REGION THIS AFTERNOON, AND
THUS, HAVE BEEN SLOWING DOWN THE TIMING OF THE RAIN. BEST GUESS AT
THIS POINT IN THE AFTERNOON, IS THAT IT SHOWS UP AROUND 23Z AT
MBL/TVC AREA, AND ABOUT 00Z AT APN/PLN. AFTER THAT THE VSBY LOOKS
TO FALL INTO THE MVFR CATEGORY, BUT THE CIGS BY 12Z/MON FALL TO
IFR AS THE LOW MOVES OVER US AND BRINGS MORE MOISTURE OVER THE
REGION.

&&

.MARINE...
ISSUED AT 402 PM EDT SUN APR 19 2015

TONIGHT THROUGH TUESDAY...EAST WINDS AHEAD OF THE SFC LOW WILL
CONTINUE TO INCREASE ACROSS THE UPPER GREAT LAKES AS THE PRESSURE
GRADIENT TIGHTENS UP ESPECIALLY OVER LAKE HURON AND E UPPER. THE SFC
LOW MOVES OVER N LAKE MICHIGAN AND IT LOOKS LIKE THE GRADIENT SHOULD
JUST BE SLACK ENOUGH FOR THE WINDS TO REMAIN BELOW MOST OF THE SMALL
CRAFT CRITERIA IN THE NEARSHORE WATERS. ONCE THE SFC LOW MOVES NORTH
OF THE UPPER MICHIGAN, THE PRESSURE GRADIENT WILL TIGHTEN BRIEFLY
OVER THE UPPER GREAT LAKES BRINGING SMALL CRAFT CRITERIA TO MOST, IF
NOT ALL OF THE NEARSHORES MONDAY AFTERNOON AND MONDAY NIGHT.
TUESDAY, AS THE SFC LOW STALLS NORTH OF LAKE SUPERIOR, THE WINDS
WILL INCREASE AS THE GRADIENT AGAIN TIGHTENS, AND THEN RELAXES BY
THE AFTERNOON.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LSZ321-322.

&&

$$

NEAR TERM...JSL
SHORT TERM...JPB
LONG TERM...GILLEN
AVIATION...JSL
MARINE...JSL



000
FXUS63 KAPX 192004
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
404 PM EDT SUN APR 19 2015

.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 402 PM EDT SUN APR 19 2015

HIGH IMPACT WEATHER: MINIMAL

FORECAST CHALLENGE: TIMING OF THE RAIN TONIGHT.

OVERVIEW...WHILE THE MOISTURE HAS BEEN INCREASING ALONG THE LAKE
HURON SHORE AND INLAND OF NE LOWER, NW LOWER HAS BEEN DRYING OUT
WITH A GOOD PORTION OF THE AREA WEST OF I-75 HAVING FALLEN BELOW
25%. IN E UPPER, THE RH HAS BEEN BETWEEN 40% AND 45%. WHAT THIS IS
DOING IS DELAYING THE RAIN SHIELD`S TRAVEL NORTH, WHICH HAD JUST
MADE IT TO THE MICHIGAN/INDIANA BORDER AROUND 19Z. USING THE TIMING
TOOL ON AWIPS, IT LOOKS LIKE THE RAIN SHOULD GET TO THE M-55
CORRIDOR AROUND 23Z, M-72 AROUND 00Z, M-32 AROUND 01Z, AND THE
STRAIT BETWEEN 02Z AND 03Z.

DETAILS FOR TONIGHT...AS WAS MENTIONED, TRYING TO TIME THIS SYSTEM
WITH THE DRY AIR IN THE LOWER LEVELS IS MADDENING. THE QUESTION
ISN`T IF THE AIR WILL LEAVE, BUT WHEN AS THE SFC LOW WILL, AS IT
MOVES UP FROM THE MID-MISSISSIPPI VALLEY, OVERWHELM WITH DRY AIR
WITH ITS MOISTURE, AND ALLOW THE RAIN TO FALL ALL THE WAY TO THE
SFC. HOWEVER, ONCE THE RAIN STARTS, IT WILL FALL THROUGH THE NIGHT
AS THE SFC NORTH OVER THE WESTERN PART OF THE STATE BETWEEN 06Z AND
12Z. THIS SFC LOW AND ASSOCIATED 500 MB SHORTWAVE TROUGH AND 50 KNOT
SPEED MAX THAT MOVES OVER THE STATE, OVER THE WARM FRONT. WITH THE
PWAT AROUND 1.0" OVERNIGHT OVER THE FORECAST AREA, WILL EXPECT
THAT A DECENT STEADY RAIN WILL RESULT.

&&

.SHORT TERM...(MONDAY THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

...SHOWERY/COOL/UNSETTLED THROUGH MIDWEEK...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: WELL-DEFINED SPLIT FLOW PATTERN FROM THE
END OF LAST WEEK NOW CONSOLIDATING AS NORTHERN BRANCH SHORT WAVE
TROUGH DIGS SOUTHEAST FROM WESTERN CANADA AND SCOOPS UP PESKY
SOUTHERN BRANCH VORTEX THAT HAS BEEN SPINNING ACROSS THE GREAT
BASIN/SOUTHERN ROCKIES SINCE THE MIDDLE OF LAST WEEK.  POSITIVE
PACIFIC TELECONNECTIONS LEADING TO A MORE AMPLIFIED PATTERN (BIG
TROUGH EAST OF THE DATELINE WITH +PNA RIDGING ALONG THE WEST COAST
OF NORTH AMERICA.  THIS CONSOLIDATING CENTRAL NORTH AMERICAN TROUGH
WILL BECOME THE PREDOMINANT WEATHER FEATURE THIS WEEK AS IT TAKES UP
RESIDENCE WITH REX BLOCKING ALONG THE WEST COAST...WITH AN UPPER LOW
EVENTUALLY PARKING ITSELF OVER THE GREAT LAKES BY MIDWEEK.

SOUTHERN BRANCH DISTURBANCE LOOKS TO COME OUT IN TWO PIECES
MONDAY...WHILE CLOSED CIRCULATION ALOFT DEVELOPS OVER NORTHWEST
ONTARIO/UPPER MIDWEST.  UPPER LOW THEN SETTLES OVER LAKE SUPERIOR
TUESDAY AND HANGS IN THROUGH MIDWEEK.  AT THE SURFACE...LEAD
SOUTHERN BRANCH SHORT WAVE TROUGH HAS AN ASSOCIATED SURFACE LOW OVER
THE MID MISSISSIPPI VALLEY THAT IS FORECAST TO DEEPEN AND LIFT NORTH
INTO LOWER MICHIGAN BY MONDAY MORNING...PROBABLY BELOW 990MB WHICH
IS PRETTY SIGNIFICANT BY MID-APRIL STANDARDS.  THIS LOW WILL PULL
COOLER AIR INTO MICHIGAN STARTING MONDAY NIGHT...CYCLONIC FLOW
LINGERS INTO MIDWEEK.

PRIMARY FORECAST CONCERNS: VARYING PRECIPITATION CHANCES THROUGH
MIDWEEK...AS WELL AS PRECIPITATION TYPE.

MONDAY...12Z SOUNDINGS AND GOES SOUNDER IMAGERY SHOWS A NICE SURGE
OF MOISTURE COMING UP ACROSS THE SOUTHEASTERN STATES (1.00-1.50 INCH
PRECIPITABLE WATER) WHICH IS PUSHING A LARGE ARE OF RAIN NORTHWARD
ACROSS THE OHIO VALLEY...AND EVENTUALLY INTO MICHIGAN TONIGHT/MONDAY
MORNING.  THIS WILL PUSH THROUGH THE FORECAST AREA MONDAY MORNING
(PERHAPS FAIRLY QUICKLY) WITH MID LEVEL DRYING (POSSIBLY TAPERING
OFF TO A PERIOD OF DRIZZLE).  SURFACE LOW TRACKS ACROSS NORTHERN
LOWER MONDAY MORNING...BEHIND THAT A LINGERING BAND OF DEFORMATION/
FRONTOGENETIC PRECIPITATION WILL ROTATE IN FROM THE WEST DURING THE
AFTERNOON HOURS.  IN ADDITION...COULD SEE SOME CONVECTIVE PRECIP
CLOSE TO THE SOUTHEAST PORTION OF THE FORECAST AREA DURING THE LATE
MORNING/AFTERNOON WITH SOME ELEVATED INSTABILITY (TQ INDICES
POTENTIALLY IN THE 16-20C RANGE NEAR LOW LEVEL THETA-E RIDGE) AND
SECOND PIECE OF SOUTHERN BRANCH ENERGY SWINGING NORTHEAST ACROSS THE
LOWER PENINSULA.  MORE LIKELY THIS ACTIVITY WOULD OCCUR ACROSS THE
THUMB INTO LAKE HURON...BUT MAY BE CLOSE.  WILL NOT TRY AND VARY
PRECIP PROBABILITIES IN THE FORECAST GRIDS TO ACCOUNT FOR TIMING OF
VARIOUS WAVES OF PRECIPITATION (AS IT WILL BE WRONG ANYHOW)...WITH A
GENERIC HIGH LIKELY/CATEGORICAL POP THROUGH THE DAY SUFFICIENT FOR
NOW. AS LONG AS INITIAL AREA OF RAIN SCOOTS NORTH QUICKLY MONDAY
MORNING... NOT EXPECT A LOT OF RAINFALL IN THE 12Z-00Z TIME FRAME
(UNLESS CONVECTION CAN CLIP FAR EASTERN ZONES DURING THE AFTERNOON)
WITH FORECAST 12H QPF UNDER 0.25 INCH THOUGH COULD BE HIGHER ACROSS
EASTERN UPPER/FAR NORTHEAST LOWER GIVEN THE ABOVE CAVEATS.  TRACK OF
THE LOW RIGHT ACROSS LOWER MICHIGAN WILL LEAD TO SOME TRICKY
TEMPERATURE FORECASTS...IN GENERAL COOLER WEST AND WARMER EAST WITH
FALLING TEMPERATURES DURING THE MID/LATE AFTERNOON AS WINDS SWITCH
AROUND TO A MORE WESTERLY COMPONENT.

WHAT REMAINS OF DEFORMATION PRECIP BAND EXPECTED TO LIFT NORTHEAST
ACROSS NORTHERN MICHIGAN MONDAY EVENING...AFTER THAT MAY BE ON THE
QUIET SIDE OVERNIGHT AND WILL CONFINE POPS TO THE EVENING HOURS.
PRECIP TYPE MAY BE IN QUESTION ACROSS EASTERN UPPER AS DEPTH OF
SURFACE BASED WARM LAYER SHRINKS.  AS NORTHERN BRANCH SHORT WAVE
TROUGHS START GETTING INVOLVED IN THE FORECAST SCENARIO CAN`T RULE
OUT SOME ADDITIONAL SHOWERS DEVELOPING OVERNIGHT INTO TUESDAY
MORNING BUT NOT CONVINCED THE PROBABILITY RISES TO A SUFFICIENT
LEVEL TO INCLUDE IN THE FORECAST...WILL LEAVE IT OUT AND MAINTAIN
CONTINUITY.

TUESDAY...DEEP LAYER CYCLONIC FLOW ACROSS THE UPPER LAKES SPELLS
UNSETTLED AND NOT WARM WEATHER FOR TUESDAY.  DEEP MOISTURE WILL
ROTATE AROUND THE SOUTH SIDE OF THE UPPER LOW...AND COOL
TEMPERATURES ALOFT (AT OR BELOW -30C/500MB) WILL ADD A DIURNAL
COMPONENT TO SUPPORT SHOWERS...AND GIVEN COOL TEMPERATURES PRECIP
COULD FALL AS RAIN/SNOW/GRAUPEL.  GUSTY SOUTHWEST WINDS (20-30MPH
GUSTS PROBABLE NORTHERN LOWER) WON`T MAKE IT FEEL ANY WARMER...WITH
AFTERNOON HIGHS AROUND 40-MID 40S (10-15 DEGREES BELOW NORMAL).
SHOWERS WILL CONTINUE INTO TUESDAY NIGHT...COVERAGE MAY DECREASE
WITH ON DOWNWARD SIDE OF DIURNAL HEATING CYCLE BUT THEY WILL STILL
BE AROUND.  COOLING TEMPERATURES ALSO WILL TREND PRECIPITATION TO
ALL SNOW SHOWERS TUESDAY EVENING.

WEDNESDAY...MORE OF THE SAME FOR WEDNESDAY WITH CONTINUED COOL
CYCLONIC FLOW AND VARIOUS DISTURBANCES ROTATING AROUND THE PARENT
VORTEX.  HIGH TEMPERATURES PROBABLY A FEW DEGREES COOLER WEDNESDAY
AFTERNOON...WITH MORE TEMPERATURES STUCK BELOW 40 DEGREES LIKELY.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

THE PERIOD PICKS UP JUST AS THE PREVIOUS LEFT OFF WITH UPPER LEVEL
TROUGHING OVERHEAD AND MULTIPLE WEAK WAVES ROTATING THROUGH THE BASE
OF THE TROUGH...BRINGING RAIN/SNOW SHOWER CHANCES WEDNESDAY NIGHT
AND INTO THE DAY THURSDAY. AS MENTIONED BY PRIOR SHIFT...THE
MOVEMENT OF THE OVERALL PATTERN LOOKS MINIMAL THROUGH THE WEEKEND
WITH TROUGHING CLOSE ENOUGH WHERE ANY SUBTLE WAVE COULD KICK OFF
ADDITIONAL SHOWER ACTIVITY. HAVE GONE AHEAD AND ADDED LOW END CHANCE
POPS FOR THURSDAY NIGHT (MAINLY DIRECTLY DOWNWIND OF LAKE MICHIGAN
AND FOR THE EASTERN U.P.)...BUT WILL KEEP A MAINLY DRY FORECAST FROM
FRIDAY THROUGH SUNDAY AS THE MAJORITY OF THE TIME LOOKS TO REMAIN
PRECIPITATION FREE.

NO DOUBT THE OVERALL PATTERN WILL BE A RATHER CHILLY ONE...WITH H8
TEMPS APPROACHING -8C THROUGHOUT THE PERIOD. A BLENDED MODEL
GUIDANCE APPROACH WOULD SUGGEST HIGH TEMPERATURES STUCK IN THE UPPER
30S AND 40S (A SOLID 10-15 DEGREES BELOW NORMAL) AND LOWS MAINLY IN
THE 20S TO LOWER 30S.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 142 PM EDT SUN APR 19 2015

MOISTURE HAS BEEN SLOW TO MOVE INTO THE REGION THIS AFTERNOON, AND
THUS, HAVE BEEN SLOWING DOWN THE TIMING OF THE RAIN. BEST GUESS AT
THIS POINT IN THE AFTERNOON, IS THAT IT SHOWS UP AROUND 23Z AT
MBL/TVC AREA, AND ABOUT 00Z AT APN/PLN. AFTER THAT THE VSBY LOOKS
TO FALL INTO THE MVFR CATEGORY, BUT THE CIGS BY 12Z/MON FALL TO
IFR AS THE LOW MOVES OVER US AND BRINGS MORE MOISTURE OVER THE
REGION.

&&

.MARINE...
ISSUED AT 402 PM EDT SUN APR 19 2015

TONIGHT THROUGH TUESDAY...EAST WINDS AHEAD OF THE SFC LOW WILL
CONTINUE TO INCREASE ACROSS THE UPPER GREAT LAKES AS THE PRESSURE
GRADIENT TIGHTENS UP ESPECIALLY OVER LAKE HURON AND E UPPER. THE SFC
LOW MOVES OVER N LAKE MICHIGAN AND IT LOOKS LIKE THE GRADIENT SHOULD
JUST BE SLACK ENOUGH FOR THE WINDS TO REMAIN BELOW MOST OF THE SMALL
CRAFT CRITERIA IN THE NEARSHORE WATERS. ONCE THE SFC LOW MOVES NORTH
OF THE UPPER MICHIGAN, THE PRESSURE GRADIENT WILL TIGHTEN BRIEFLY
OVER THE UPPER GREAT LAKES BRINGING SMALL CRAFT CRITERIA TO MOST, IF
NOT ALL OF THE NEARSHORES MONDAY AFTERNOON AND MONDAY NIGHT.
TUESDAY, AS THE SFC LOW STALLS NORTH OF LAKE SUPERIOR, THE WINDS
WILL INCREASE AS THE GRADIENT AGAIN TIGHTENS, AND THEN RELAXES BY
THE AFTERNOON.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LSZ321-322.

&&

$$

NEAR TERM...JSL
SHORT TERM...JPB
LONG TERM...GILLEN
AVIATION...JSL
MARINE...JSL




000
FXUS63 KAPX 192004
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
404 PM EDT SUN APR 19 2015

.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 402 PM EDT SUN APR 19 2015

HIGH IMPACT WEATHER: MINIMAL

FORECAST CHALLENGE: TIMING OF THE RAIN TONIGHT.

OVERVIEW...WHILE THE MOISTURE HAS BEEN INCREASING ALONG THE LAKE
HURON SHORE AND INLAND OF NE LOWER, NW LOWER HAS BEEN DRYING OUT
WITH A GOOD PORTION OF THE AREA WEST OF I-75 HAVING FALLEN BELOW
25%. IN E UPPER, THE RH HAS BEEN BETWEEN 40% AND 45%. WHAT THIS IS
DOING IS DELAYING THE RAIN SHIELD`S TRAVEL NORTH, WHICH HAD JUST
MADE IT TO THE MICHIGAN/INDIANA BORDER AROUND 19Z. USING THE TIMING
TOOL ON AWIPS, IT LOOKS LIKE THE RAIN SHOULD GET TO THE M-55
CORRIDOR AROUND 23Z, M-72 AROUND 00Z, M-32 AROUND 01Z, AND THE
STRAIT BETWEEN 02Z AND 03Z.

DETAILS FOR TONIGHT...AS WAS MENTIONED, TRYING TO TIME THIS SYSTEM
WITH THE DRY AIR IN THE LOWER LEVELS IS MADDENING. THE QUESTION
ISN`T IF THE AIR WILL LEAVE, BUT WHEN AS THE SFC LOW WILL, AS IT
MOVES UP FROM THE MID-MISSISSIPPI VALLEY, OVERWHELM WITH DRY AIR
WITH ITS MOISTURE, AND ALLOW THE RAIN TO FALL ALL THE WAY TO THE
SFC. HOWEVER, ONCE THE RAIN STARTS, IT WILL FALL THROUGH THE NIGHT
AS THE SFC NORTH OVER THE WESTERN PART OF THE STATE BETWEEN 06Z AND
12Z. THIS SFC LOW AND ASSOCIATED 500 MB SHORTWAVE TROUGH AND 50 KNOT
SPEED MAX THAT MOVES OVER THE STATE, OVER THE WARM FRONT. WITH THE
PWAT AROUND 1.0" OVERNIGHT OVER THE FORECAST AREA, WILL EXPECT
THAT A DECENT STEADY RAIN WILL RESULT.

&&

.SHORT TERM...(MONDAY THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

...SHOWERY/COOL/UNSETTLED THROUGH MIDWEEK...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: WELL-DEFINED SPLIT FLOW PATTERN FROM THE
END OF LAST WEEK NOW CONSOLIDATING AS NORTHERN BRANCH SHORT WAVE
TROUGH DIGS SOUTHEAST FROM WESTERN CANADA AND SCOOPS UP PESKY
SOUTHERN BRANCH VORTEX THAT HAS BEEN SPINNING ACROSS THE GREAT
BASIN/SOUTHERN ROCKIES SINCE THE MIDDLE OF LAST WEEK.  POSITIVE
PACIFIC TELECONNECTIONS LEADING TO A MORE AMPLIFIED PATTERN (BIG
TROUGH EAST OF THE DATELINE WITH +PNA RIDGING ALONG THE WEST COAST
OF NORTH AMERICA.  THIS CONSOLIDATING CENTRAL NORTH AMERICAN TROUGH
WILL BECOME THE PREDOMINANT WEATHER FEATURE THIS WEEK AS IT TAKES UP
RESIDENCE WITH REX BLOCKING ALONG THE WEST COAST...WITH AN UPPER LOW
EVENTUALLY PARKING ITSELF OVER THE GREAT LAKES BY MIDWEEK.

SOUTHERN BRANCH DISTURBANCE LOOKS TO COME OUT IN TWO PIECES
MONDAY...WHILE CLOSED CIRCULATION ALOFT DEVELOPS OVER NORTHWEST
ONTARIO/UPPER MIDWEST.  UPPER LOW THEN SETTLES OVER LAKE SUPERIOR
TUESDAY AND HANGS IN THROUGH MIDWEEK.  AT THE SURFACE...LEAD
SOUTHERN BRANCH SHORT WAVE TROUGH HAS AN ASSOCIATED SURFACE LOW OVER
THE MID MISSISSIPPI VALLEY THAT IS FORECAST TO DEEPEN AND LIFT NORTH
INTO LOWER MICHIGAN BY MONDAY MORNING...PROBABLY BELOW 990MB WHICH
IS PRETTY SIGNIFICANT BY MID-APRIL STANDARDS.  THIS LOW WILL PULL
COOLER AIR INTO MICHIGAN STARTING MONDAY NIGHT...CYCLONIC FLOW
LINGERS INTO MIDWEEK.

PRIMARY FORECAST CONCERNS: VARYING PRECIPITATION CHANCES THROUGH
MIDWEEK...AS WELL AS PRECIPITATION TYPE.

MONDAY...12Z SOUNDINGS AND GOES SOUNDER IMAGERY SHOWS A NICE SURGE
OF MOISTURE COMING UP ACROSS THE SOUTHEASTERN STATES (1.00-1.50 INCH
PRECIPITABLE WATER) WHICH IS PUSHING A LARGE ARE OF RAIN NORTHWARD
ACROSS THE OHIO VALLEY...AND EVENTUALLY INTO MICHIGAN TONIGHT/MONDAY
MORNING.  THIS WILL PUSH THROUGH THE FORECAST AREA MONDAY MORNING
(PERHAPS FAIRLY QUICKLY) WITH MID LEVEL DRYING (POSSIBLY TAPERING
OFF TO A PERIOD OF DRIZZLE).  SURFACE LOW TRACKS ACROSS NORTHERN
LOWER MONDAY MORNING...BEHIND THAT A LINGERING BAND OF DEFORMATION/
FRONTOGENETIC PRECIPITATION WILL ROTATE IN FROM THE WEST DURING THE
AFTERNOON HOURS.  IN ADDITION...COULD SEE SOME CONVECTIVE PRECIP
CLOSE TO THE SOUTHEAST PORTION OF THE FORECAST AREA DURING THE LATE
MORNING/AFTERNOON WITH SOME ELEVATED INSTABILITY (TQ INDICES
POTENTIALLY IN THE 16-20C RANGE NEAR LOW LEVEL THETA-E RIDGE) AND
SECOND PIECE OF SOUTHERN BRANCH ENERGY SWINGING NORTHEAST ACROSS THE
LOWER PENINSULA.  MORE LIKELY THIS ACTIVITY WOULD OCCUR ACROSS THE
THUMB INTO LAKE HURON...BUT MAY BE CLOSE.  WILL NOT TRY AND VARY
PRECIP PROBABILITIES IN THE FORECAST GRIDS TO ACCOUNT FOR TIMING OF
VARIOUS WAVES OF PRECIPITATION (AS IT WILL BE WRONG ANYHOW)...WITH A
GENERIC HIGH LIKELY/CATEGORICAL POP THROUGH THE DAY SUFFICIENT FOR
NOW. AS LONG AS INITIAL AREA OF RAIN SCOOTS NORTH QUICKLY MONDAY
MORNING... NOT EXPECT A LOT OF RAINFALL IN THE 12Z-00Z TIME FRAME
(UNLESS CONVECTION CAN CLIP FAR EASTERN ZONES DURING THE AFTERNOON)
WITH FORECAST 12H QPF UNDER 0.25 INCH THOUGH COULD BE HIGHER ACROSS
EASTERN UPPER/FAR NORTHEAST LOWER GIVEN THE ABOVE CAVEATS.  TRACK OF
THE LOW RIGHT ACROSS LOWER MICHIGAN WILL LEAD TO SOME TRICKY
TEMPERATURE FORECASTS...IN GENERAL COOLER WEST AND WARMER EAST WITH
FALLING TEMPERATURES DURING THE MID/LATE AFTERNOON AS WINDS SWITCH
AROUND TO A MORE WESTERLY COMPONENT.

WHAT REMAINS OF DEFORMATION PRECIP BAND EXPECTED TO LIFT NORTHEAST
ACROSS NORTHERN MICHIGAN MONDAY EVENING...AFTER THAT MAY BE ON THE
QUIET SIDE OVERNIGHT AND WILL CONFINE POPS TO THE EVENING HOURS.
PRECIP TYPE MAY BE IN QUESTION ACROSS EASTERN UPPER AS DEPTH OF
SURFACE BASED WARM LAYER SHRINKS.  AS NORTHERN BRANCH SHORT WAVE
TROUGHS START GETTING INVOLVED IN THE FORECAST SCENARIO CAN`T RULE
OUT SOME ADDITIONAL SHOWERS DEVELOPING OVERNIGHT INTO TUESDAY
MORNING BUT NOT CONVINCED THE PROBABILITY RISES TO A SUFFICIENT
LEVEL TO INCLUDE IN THE FORECAST...WILL LEAVE IT OUT AND MAINTAIN
CONTINUITY.

TUESDAY...DEEP LAYER CYCLONIC FLOW ACROSS THE UPPER LAKES SPELLS
UNSETTLED AND NOT WARM WEATHER FOR TUESDAY.  DEEP MOISTURE WILL
ROTATE AROUND THE SOUTH SIDE OF THE UPPER LOW...AND COOL
TEMPERATURES ALOFT (AT OR BELOW -30C/500MB) WILL ADD A DIURNAL
COMPONENT TO SUPPORT SHOWERS...AND GIVEN COOL TEMPERATURES PRECIP
COULD FALL AS RAIN/SNOW/GRAUPEL.  GUSTY SOUTHWEST WINDS (20-30MPH
GUSTS PROBABLE NORTHERN LOWER) WON`T MAKE IT FEEL ANY WARMER...WITH
AFTERNOON HIGHS AROUND 40-MID 40S (10-15 DEGREES BELOW NORMAL).
SHOWERS WILL CONTINUE INTO TUESDAY NIGHT...COVERAGE MAY DECREASE
WITH ON DOWNWARD SIDE OF DIURNAL HEATING CYCLE BUT THEY WILL STILL
BE AROUND.  COOLING TEMPERATURES ALSO WILL TREND PRECIPITATION TO
ALL SNOW SHOWERS TUESDAY EVENING.

WEDNESDAY...MORE OF THE SAME FOR WEDNESDAY WITH CONTINUED COOL
CYCLONIC FLOW AND VARIOUS DISTURBANCES ROTATING AROUND THE PARENT
VORTEX.  HIGH TEMPERATURES PROBABLY A FEW DEGREES COOLER WEDNESDAY
AFTERNOON...WITH MORE TEMPERATURES STUCK BELOW 40 DEGREES LIKELY.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

THE PERIOD PICKS UP JUST AS THE PREVIOUS LEFT OFF WITH UPPER LEVEL
TROUGHING OVERHEAD AND MULTIPLE WEAK WAVES ROTATING THROUGH THE BASE
OF THE TROUGH...BRINGING RAIN/SNOW SHOWER CHANCES WEDNESDAY NIGHT
AND INTO THE DAY THURSDAY. AS MENTIONED BY PRIOR SHIFT...THE
MOVEMENT OF THE OVERALL PATTERN LOOKS MINIMAL THROUGH THE WEEKEND
WITH TROUGHING CLOSE ENOUGH WHERE ANY SUBTLE WAVE COULD KICK OFF
ADDITIONAL SHOWER ACTIVITY. HAVE GONE AHEAD AND ADDED LOW END CHANCE
POPS FOR THURSDAY NIGHT (MAINLY DIRECTLY DOWNWIND OF LAKE MICHIGAN
AND FOR THE EASTERN U.P.)...BUT WILL KEEP A MAINLY DRY FORECAST FROM
FRIDAY THROUGH SUNDAY AS THE MAJORITY OF THE TIME LOOKS TO REMAIN
PRECIPITATION FREE.

NO DOUBT THE OVERALL PATTERN WILL BE A RATHER CHILLY ONE...WITH H8
TEMPS APPROACHING -8C THROUGHOUT THE PERIOD. A BLENDED MODEL
GUIDANCE APPROACH WOULD SUGGEST HIGH TEMPERATURES STUCK IN THE UPPER
30S AND 40S (A SOLID 10-15 DEGREES BELOW NORMAL) AND LOWS MAINLY IN
THE 20S TO LOWER 30S.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 142 PM EDT SUN APR 19 2015

MOISTURE HAS BEEN SLOW TO MOVE INTO THE REGION THIS AFTERNOON, AND
THUS, HAVE BEEN SLOWING DOWN THE TIMING OF THE RAIN. BEST GUESS AT
THIS POINT IN THE AFTERNOON, IS THAT IT SHOWS UP AROUND 23Z AT
MBL/TVC AREA, AND ABOUT 00Z AT APN/PLN. AFTER THAT THE VSBY LOOKS
TO FALL INTO THE MVFR CATEGORY, BUT THE CIGS BY 12Z/MON FALL TO
IFR AS THE LOW MOVES OVER US AND BRINGS MORE MOISTURE OVER THE
REGION.

&&

.MARINE...
ISSUED AT 402 PM EDT SUN APR 19 2015

TONIGHT THROUGH TUESDAY...EAST WINDS AHEAD OF THE SFC LOW WILL
CONTINUE TO INCREASE ACROSS THE UPPER GREAT LAKES AS THE PRESSURE
GRADIENT TIGHTENS UP ESPECIALLY OVER LAKE HURON AND E UPPER. THE SFC
LOW MOVES OVER N LAKE MICHIGAN AND IT LOOKS LIKE THE GRADIENT SHOULD
JUST BE SLACK ENOUGH FOR THE WINDS TO REMAIN BELOW MOST OF THE SMALL
CRAFT CRITERIA IN THE NEARSHORE WATERS. ONCE THE SFC LOW MOVES NORTH
OF THE UPPER MICHIGAN, THE PRESSURE GRADIENT WILL TIGHTEN BRIEFLY
OVER THE UPPER GREAT LAKES BRINGING SMALL CRAFT CRITERIA TO MOST, IF
NOT ALL OF THE NEARSHORES MONDAY AFTERNOON AND MONDAY NIGHT.
TUESDAY, AS THE SFC LOW STALLS NORTH OF LAKE SUPERIOR, THE WINDS
WILL INCREASE AS THE GRADIENT AGAIN TIGHTENS, AND THEN RELAXES BY
THE AFTERNOON.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LSZ321-322.

&&

$$

NEAR TERM...JSL
SHORT TERM...JPB
LONG TERM...GILLEN
AVIATION...JSL
MARINE...JSL



000
FXUS63 KAPX 192004
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
404 PM EDT SUN APR 19 2015

.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 402 PM EDT SUN APR 19 2015

HIGH IMPACT WEATHER: MINIMAL

FORECAST CHALLENGE: TIMING OF THE RAIN TONIGHT.

OVERVIEW...WHILE THE MOISTURE HAS BEEN INCREASING ALONG THE LAKE
HURON SHORE AND INLAND OF NE LOWER, NW LOWER HAS BEEN DRYING OUT
WITH A GOOD PORTION OF THE AREA WEST OF I-75 HAVING FALLEN BELOW
25%. IN E UPPER, THE RH HAS BEEN BETWEEN 40% AND 45%. WHAT THIS IS
DOING IS DELAYING THE RAIN SHIELD`S TRAVEL NORTH, WHICH HAD JUST
MADE IT TO THE MICHIGAN/INDIANA BORDER AROUND 19Z. USING THE TIMING
TOOL ON AWIPS, IT LOOKS LIKE THE RAIN SHOULD GET TO THE M-55
CORRIDOR AROUND 23Z, M-72 AROUND 00Z, M-32 AROUND 01Z, AND THE
STRAIT BETWEEN 02Z AND 03Z.

DETAILS FOR TONIGHT...AS WAS MENTIONED, TRYING TO TIME THIS SYSTEM
WITH THE DRY AIR IN THE LOWER LEVELS IS MADDENING. THE QUESTION
ISN`T IF THE AIR WILL LEAVE, BUT WHEN AS THE SFC LOW WILL, AS IT
MOVES UP FROM THE MID-MISSISSIPPI VALLEY, OVERWHELM WITH DRY AIR
WITH ITS MOISTURE, AND ALLOW THE RAIN TO FALL ALL THE WAY TO THE
SFC. HOWEVER, ONCE THE RAIN STARTS, IT WILL FALL THROUGH THE NIGHT
AS THE SFC NORTH OVER THE WESTERN PART OF THE STATE BETWEEN 06Z AND
12Z. THIS SFC LOW AND ASSOCIATED 500 MB SHORTWAVE TROUGH AND 50 KNOT
SPEED MAX THAT MOVES OVER THE STATE, OVER THE WARM FRONT. WITH THE
PWAT AROUND 1.0" OVERNIGHT OVER THE FORECAST AREA, WILL EXPECT
THAT A DECENT STEADY RAIN WILL RESULT.

&&

.SHORT TERM...(MONDAY THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

...SHOWERY/COOL/UNSETTLED THROUGH MIDWEEK...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: WELL-DEFINED SPLIT FLOW PATTERN FROM THE
END OF LAST WEEK NOW CONSOLIDATING AS NORTHERN BRANCH SHORT WAVE
TROUGH DIGS SOUTHEAST FROM WESTERN CANADA AND SCOOPS UP PESKY
SOUTHERN BRANCH VORTEX THAT HAS BEEN SPINNING ACROSS THE GREAT
BASIN/SOUTHERN ROCKIES SINCE THE MIDDLE OF LAST WEEK.  POSITIVE
PACIFIC TELECONNECTIONS LEADING TO A MORE AMPLIFIED PATTERN (BIG
TROUGH EAST OF THE DATELINE WITH +PNA RIDGING ALONG THE WEST COAST
OF NORTH AMERICA.  THIS CONSOLIDATING CENTRAL NORTH AMERICAN TROUGH
WILL BECOME THE PREDOMINANT WEATHER FEATURE THIS WEEK AS IT TAKES UP
RESIDENCE WITH REX BLOCKING ALONG THE WEST COAST...WITH AN UPPER LOW
EVENTUALLY PARKING ITSELF OVER THE GREAT LAKES BY MIDWEEK.

SOUTHERN BRANCH DISTURBANCE LOOKS TO COME OUT IN TWO PIECES
MONDAY...WHILE CLOSED CIRCULATION ALOFT DEVELOPS OVER NORTHWEST
ONTARIO/UPPER MIDWEST.  UPPER LOW THEN SETTLES OVER LAKE SUPERIOR
TUESDAY AND HANGS IN THROUGH MIDWEEK.  AT THE SURFACE...LEAD
SOUTHERN BRANCH SHORT WAVE TROUGH HAS AN ASSOCIATED SURFACE LOW OVER
THE MID MISSISSIPPI VALLEY THAT IS FORECAST TO DEEPEN AND LIFT NORTH
INTO LOWER MICHIGAN BY MONDAY MORNING...PROBABLY BELOW 990MB WHICH
IS PRETTY SIGNIFICANT BY MID-APRIL STANDARDS.  THIS LOW WILL PULL
COOLER AIR INTO MICHIGAN STARTING MONDAY NIGHT...CYCLONIC FLOW
LINGERS INTO MIDWEEK.

PRIMARY FORECAST CONCERNS: VARYING PRECIPITATION CHANCES THROUGH
MIDWEEK...AS WELL AS PRECIPITATION TYPE.

MONDAY...12Z SOUNDINGS AND GOES SOUNDER IMAGERY SHOWS A NICE SURGE
OF MOISTURE COMING UP ACROSS THE SOUTHEASTERN STATES (1.00-1.50 INCH
PRECIPITABLE WATER) WHICH IS PUSHING A LARGE ARE OF RAIN NORTHWARD
ACROSS THE OHIO VALLEY...AND EVENTUALLY INTO MICHIGAN TONIGHT/MONDAY
MORNING.  THIS WILL PUSH THROUGH THE FORECAST AREA MONDAY MORNING
(PERHAPS FAIRLY QUICKLY) WITH MID LEVEL DRYING (POSSIBLY TAPERING
OFF TO A PERIOD OF DRIZZLE).  SURFACE LOW TRACKS ACROSS NORTHERN
LOWER MONDAY MORNING...BEHIND THAT A LINGERING BAND OF DEFORMATION/
FRONTOGENETIC PRECIPITATION WILL ROTATE IN FROM THE WEST DURING THE
AFTERNOON HOURS.  IN ADDITION...COULD SEE SOME CONVECTIVE PRECIP
CLOSE TO THE SOUTHEAST PORTION OF THE FORECAST AREA DURING THE LATE
MORNING/AFTERNOON WITH SOME ELEVATED INSTABILITY (TQ INDICES
POTENTIALLY IN THE 16-20C RANGE NEAR LOW LEVEL THETA-E RIDGE) AND
SECOND PIECE OF SOUTHERN BRANCH ENERGY SWINGING NORTHEAST ACROSS THE
LOWER PENINSULA.  MORE LIKELY THIS ACTIVITY WOULD OCCUR ACROSS THE
THUMB INTO LAKE HURON...BUT MAY BE CLOSE.  WILL NOT TRY AND VARY
PRECIP PROBABILITIES IN THE FORECAST GRIDS TO ACCOUNT FOR TIMING OF
VARIOUS WAVES OF PRECIPITATION (AS IT WILL BE WRONG ANYHOW)...WITH A
GENERIC HIGH LIKELY/CATEGORICAL POP THROUGH THE DAY SUFFICIENT FOR
NOW. AS LONG AS INITIAL AREA OF RAIN SCOOTS NORTH QUICKLY MONDAY
MORNING... NOT EXPECT A LOT OF RAINFALL IN THE 12Z-00Z TIME FRAME
(UNLESS CONVECTION CAN CLIP FAR EASTERN ZONES DURING THE AFTERNOON)
WITH FORECAST 12H QPF UNDER 0.25 INCH THOUGH COULD BE HIGHER ACROSS
EASTERN UPPER/FAR NORTHEAST LOWER GIVEN THE ABOVE CAVEATS.  TRACK OF
THE LOW RIGHT ACROSS LOWER MICHIGAN WILL LEAD TO SOME TRICKY
TEMPERATURE FORECASTS...IN GENERAL COOLER WEST AND WARMER EAST WITH
FALLING TEMPERATURES DURING THE MID/LATE AFTERNOON AS WINDS SWITCH
AROUND TO A MORE WESTERLY COMPONENT.

WHAT REMAINS OF DEFORMATION PRECIP BAND EXPECTED TO LIFT NORTHEAST
ACROSS NORTHERN MICHIGAN MONDAY EVENING...AFTER THAT MAY BE ON THE
QUIET SIDE OVERNIGHT AND WILL CONFINE POPS TO THE EVENING HOURS.
PRECIP TYPE MAY BE IN QUESTION ACROSS EASTERN UPPER AS DEPTH OF
SURFACE BASED WARM LAYER SHRINKS.  AS NORTHERN BRANCH SHORT WAVE
TROUGHS START GETTING INVOLVED IN THE FORECAST SCENARIO CAN`T RULE
OUT SOME ADDITIONAL SHOWERS DEVELOPING OVERNIGHT INTO TUESDAY
MORNING BUT NOT CONVINCED THE PROBABILITY RISES TO A SUFFICIENT
LEVEL TO INCLUDE IN THE FORECAST...WILL LEAVE IT OUT AND MAINTAIN
CONTINUITY.

TUESDAY...DEEP LAYER CYCLONIC FLOW ACROSS THE UPPER LAKES SPELLS
UNSETTLED AND NOT WARM WEATHER FOR TUESDAY.  DEEP MOISTURE WILL
ROTATE AROUND THE SOUTH SIDE OF THE UPPER LOW...AND COOL
TEMPERATURES ALOFT (AT OR BELOW -30C/500MB) WILL ADD A DIURNAL
COMPONENT TO SUPPORT SHOWERS...AND GIVEN COOL TEMPERATURES PRECIP
COULD FALL AS RAIN/SNOW/GRAUPEL.  GUSTY SOUTHWEST WINDS (20-30MPH
GUSTS PROBABLE NORTHERN LOWER) WON`T MAKE IT FEEL ANY WARMER...WITH
AFTERNOON HIGHS AROUND 40-MID 40S (10-15 DEGREES BELOW NORMAL).
SHOWERS WILL CONTINUE INTO TUESDAY NIGHT...COVERAGE MAY DECREASE
WITH ON DOWNWARD SIDE OF DIURNAL HEATING CYCLE BUT THEY WILL STILL
BE AROUND.  COOLING TEMPERATURES ALSO WILL TREND PRECIPITATION TO
ALL SNOW SHOWERS TUESDAY EVENING.

WEDNESDAY...MORE OF THE SAME FOR WEDNESDAY WITH CONTINUED COOL
CYCLONIC FLOW AND VARIOUS DISTURBANCES ROTATING AROUND THE PARENT
VORTEX.  HIGH TEMPERATURES PROBABLY A FEW DEGREES COOLER WEDNESDAY
AFTERNOON...WITH MORE TEMPERATURES STUCK BELOW 40 DEGREES LIKELY.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 402 PM EDT SUN APR 19 2015

THE PERIOD PICKS UP JUST AS THE PREVIOUS LEFT OFF WITH UPPER LEVEL
TROUGHING OVERHEAD AND MULTIPLE WEAK WAVES ROTATING THROUGH THE BASE
OF THE TROUGH...BRINGING RAIN/SNOW SHOWER CHANCES WEDNESDAY NIGHT
AND INTO THE DAY THURSDAY. AS MENTIONED BY PRIOR SHIFT...THE
MOVEMENT OF THE OVERALL PATTERN LOOKS MINIMAL THROUGH THE WEEKEND
WITH TROUGHING CLOSE ENOUGH WHERE ANY SUBTLE WAVE COULD KICK OFF
ADDITIONAL SHOWER ACTIVITY. HAVE GONE AHEAD AND ADDED LOW END CHANCE
POPS FOR THURSDAY NIGHT (MAINLY DIRECTLY DOWNWIND OF LAKE MICHIGAN
AND FOR THE EASTERN U.P.)...BUT WILL KEEP A MAINLY DRY FORECAST FROM
FRIDAY THROUGH SUNDAY AS THE MAJORITY OF THE TIME LOOKS TO REMAIN
PRECIPITATION FREE.

NO DOUBT THE OVERALL PATTERN WILL BE A RATHER CHILLY ONE...WITH H8
TEMPS APPROACHING -8C THROUGHOUT THE PERIOD. A BLENDED MODEL
GUIDANCE APPROACH WOULD SUGGEST HIGH TEMPERATURES STUCK IN THE UPPER
30S AND 40S (A SOLID 10-15 DEGREES BELOW NORMAL) AND LOWS MAINLY IN
THE 20S TO LOWER 30S.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 142 PM EDT SUN APR 19 2015

MOISTURE HAS BEEN SLOW TO MOVE INTO THE REGION THIS AFTERNOON, AND
THUS, HAVE BEEN SLOWING DOWN THE TIMING OF THE RAIN. BEST GUESS AT
THIS POINT IN THE AFTERNOON, IS THAT IT SHOWS UP AROUND 23Z AT
MBL/TVC AREA, AND ABOUT 00Z AT APN/PLN. AFTER THAT THE VSBY LOOKS
TO FALL INTO THE MVFR CATEGORY, BUT THE CIGS BY 12Z/MON FALL TO
IFR AS THE LOW MOVES OVER US AND BRINGS MORE MOISTURE OVER THE
REGION.

&&

.MARINE...
ISSUED AT 402 PM EDT SUN APR 19 2015

TONIGHT THROUGH TUESDAY...EAST WINDS AHEAD OF THE SFC LOW WILL
CONTINUE TO INCREASE ACROSS THE UPPER GREAT LAKES AS THE PRESSURE
GRADIENT TIGHTENS UP ESPECIALLY OVER LAKE HURON AND E UPPER. THE SFC
LOW MOVES OVER N LAKE MICHIGAN AND IT LOOKS LIKE THE GRADIENT SHOULD
JUST BE SLACK ENOUGH FOR THE WINDS TO REMAIN BELOW MOST OF THE SMALL
CRAFT CRITERIA IN THE NEARSHORE WATERS. ONCE THE SFC LOW MOVES NORTH
OF THE UPPER MICHIGAN, THE PRESSURE GRADIENT WILL TIGHTEN BRIEFLY
OVER THE UPPER GREAT LAKES BRINGING SMALL CRAFT CRITERIA TO MOST, IF
NOT ALL OF THE NEARSHORES MONDAY AFTERNOON AND MONDAY NIGHT.
TUESDAY, AS THE SFC LOW STALLS NORTH OF LAKE SUPERIOR, THE WINDS
WILL INCREASE AS THE GRADIENT AGAIN TIGHTENS, AND THEN RELAXES BY
THE AFTERNOON.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LSZ321-322.

&&

$$

NEAR TERM...JSL
SHORT TERM...JPB
LONG TERM...GILLEN
AVIATION...JSL
MARINE...JSL




000
FXUS63 KDTX 191956
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
356 PM EDT SUN APR 19 2015

.SHORT TERM...TONIGHT

THE ARC OF SHOWER ACTIVITY FORCED ON AN INITIAL SURGE/GRADIENT OF
850-700MB MOISTURE HAS STRUGGLED FROM A VIGOR PERSPECTIVE DUE TO A
LACK OF INSTABILITY. WITH SHOWERS WORKING UP THE FRONTAL SLOPE AS IT
TRACKS NORTHWARD...EXPECT THE WEAK NATURE TO CONTINUE.

THE MAIN BAND OF SYNOPTIC FORCING AND WIDESPREAD RAIN ACTIVITY WILL
LIFT ACROSS THE OHIO AND MICHIGAN BORDER AROUND 21Z. REGIONAL MOSAIC
AS OF 19Z... SHOWS THE MIDLEVELS SATURATING SOUTH OF TOLEDO. REALLY
A TREMENDOUS AMOUNT OF SYNOPTIC SCALE SUPPORT FOR LIFT AND
PRECIPITATION GENERATION TONIGHT AS SOUTHEASTERN MICHIGAN REMAINS
FAVORABLY POSITIONED AHEAD OF A HIGH AMPLITUDE WARM SECTOR
STRUCTURE AND OPTIMAL WARM AIR ADVECTION. EVERYTHING APPEARS TO BE
LINING UP FROM A FORCING STANDPOINT FOR A FAVORABLE PERIOD OF
WIDESPREAD RAIN INCLUDING A POTENTIAL FOR HEAVY RAINFALL.
SPECIFICALLY...LARGE BULLSEYE OF 1000-500MB HEIGHT FALLS...LINKAGE
OF RIGHT NOSE OF LOW LEVEL JET AXIS WITH RIGHT ENTRANCE REGION
DYNAMICS ALOFT...AND A DIRECT HIT FROM A SECONDARY VORTICITY
MAXIMUM. NWP SUPPORTS THIS SECONDARY VORTICITY MAXIMUM BECOMING
ORGANIZED/STRENGTHENING NEAR LOUISVILLE NOW AND LIFTING INTO FAR
SOUTHEASTERN MICHIGAN BETWEEN 00-03Z. NAM REALLY BITES ON THIS
FEATURE SHOWING DEPICTIONS OF A PSEUDO SHARS TYPE RESPONSE AND
HIGH AMOUNTS OF 3HR QPF. BROAD NATIONAL MOSAIC OF REFLECTIVITY
ALONG WITH SATELLITE IMAGERY OF CLEARING/DESTABILIZING STRAIGHT
INTO CENTRAL KENTUCKY SUPPORTS THIS STRONG SOLUTION OF THE
SECONDARY VORTICITY MAXIMUM. THUS...THE EARLIER FORECAST OF
FORECASTING QPF AMOUNTS OF UPWARDS OF 1.00 INCH FOR FAR
SOUTHEASTERN MICHIGAN INCLUDING THE DETROIT METRO APPEARS
REASONABLE. THERE AT LEAST REMAINS SOME POTENTIAL THAT THIS DRY
AIR/SLOT COULD WORK NORTHWARD AT A CRITICAL TRAJECTORY AND CAUSE
HEAVY PRECIPITATION TO DEFLECT AWAY FROM THE CWA. CONFIDENCE IN
PROJECTING THAT OUT IS LOW. WHILE FORECASTED QPF AMOUNTS ARE
RELATIVELY HIGH FROM AN EVENT STANDPOINT...THE STEADY NORTHWARD
PROGRESSION OF SHOWERS/EMBEDDED THUNDER WILL LIMIT THE CONCERN FOR
FLOODING.

&&

.LONG TERM...

STRONG LOW PRESSURE WILL CONTINUE TO DEEPEN AS IT LIFTS NORTHWARD
THROUGH NORTHERN LOWER MICHIGAN INTO ONTARIO ON MONDAY. MODELS HAVE
TRENDED SLIGHTLY SLOWLY AND FURTHER WEST WITH THE TRACK OF THIS
SYSTEM...AND THIS WILL MOSTLY LIKELY HAVE SOME NOTABLE IMPLICATIONS
TO THE GOING FORECAST. AS SUCH...HAVE MADE A FEW ADJUSTMENTS FOR
THIS PACKAGE.

THE "NEW" CONSENSUS TRACK FORECAST WILL ESSENTIALLY DELAY THE COLD
FRONTAL PASSAGE THROUGH THE AREA UNTIL LATE AFTERNOON AND ALLOW FOR
TEMPERATURES TO CLIMB WELL INTO THE 60S OVER A GOOD PORTION OF THE
AREA. THIS...IN TURN...WILL ALLOW FOR SOME DESTABILIZATION AS SBCAPE
VALUES CLIMB TO AROUND 500 J/KG BY AFTERNOON. THIS SHOULD ALLOW FOR
MORE VIGOROUS CONVECTION ALONG THE COLD FRONT WITH THE POTENTIAL FOR
HAIL INCREASING AS FREEZING LEVELS DROP BELOW 7000-8000 FEET AS COLD
AIR WRAP AROUND THE UPPER CIRCULATION.

IN ADDITION...THIS ACTIVITY WILL LIKELY PRODUCE SOME GUSTY WINDS AS
DEEP SWATH OF 35 TO 40 KT SOUTHWEST FLOW OVERSPREADS THE AREA. EVEN
OUTSIDE OF STORMS...WIND GUSTS WILL LIKELY REACH 35 MPH AT TIMES BY
AFTERNOON AND HAVE UPPED THE OVERALL FORECAST WINDS A FAIR AMOUNT.
WHILE WIDESPREAD STRONG STORMS ARE PROBABLY NOT TOO LIKELY...A FEW
WILL CERTAINLY BECOME A BIT ROBUST AS FORCING ALONG THE COLD FRONT
HELPS FOCUS THE MARGINAL INSTABILITY THAT IS ABLE TO BUILD OVER
PARTS OF THE AREA.

CONDITIONS WILL QUIET FROM MID EVENING INTO TUESDAY AS THE LOW LIFTS
TO NEAR JAMES BAY AND STALLS. THAT SAID...CONDITIONS WILL REMAIN
RATHER UNSETTLED INTO THE TUESDAY AND TUESDAY NIGHT PERIOD AS THIS
LOW ONLY GRADUALLY WEAKENS. EXPECT COOLER TEMPERATURES AND CONTINUE
GUSTY WINDS WITH SCATTERED RAIN SHOWERS DOTTING THE REGION...MAINLY
IN THE TUESDAY AFTERNOON PERIOD DURING THE DIURNAL TEMPERATURE AND
INSTABILITY MAX. DOWNSLOPING WEST/SOUTHWEST FLOW SHOULD ALLOW METRO
DETROIT AND SURROUNDING AREAS TO CLIMB INTO THE MID 50S DESPITE THE
MUCH COLDER AIRMASS...BUT STILL EXPECT LOWS WELL INTO THE 30S BY
TUESDAY NIGHT AS THE COLD AIRMASS DEEPENS OVER THE AREA.

EXTENDED FORECAST STARTING WEDNESDAY AND INTO NEXT WEEKEND WILL BE
RELATIVELY QUIET AS FAR AS PRECIPITATION GOES WITH BELOW NORMAL
TEMPERATURES.  COOLER AIR WILL CONTINUE TO FILTER INTO THE REGION AS
THE GREAT LAKES RESIDES IN THE PERSISTENT LONGWAVE TROUGHING.  WHILE
THERE WILL BE SLIGHT PRECIPITATION CHANCES WHILE THE REGION RESIDES
IN THE TROUGH...THE CAVEAT IS THE LACK OF MOISTURE THAT WILL BE
AVAILABLE.  RIDGING DOES NOT LOOK TO START BUILDING INTO THE WESTERN
GREAT LAKES REGION UNTIL THE END OF THE FORECAST PERIOD.

&&

.MARINE...

EAST FLOW WILL GRADUALLY BECOME SOUTHEAST TONIGHT AS DEEPENING LOW
PRESSURE PUSHES A WARM FRONT THROUGH THE AREA. DURING THIS TIME
FRAME...EXPECT STEADILY INCREASING WIND SPEEDS WHICH WILL ALLOW
WAVES TO BUILD. AS THIS LOW PASSES INTO THE NORTHERN GREAT LAKES
MONDAY...WINDS REMAIN GUSTY AND VEER TO THE SOUTH AND THEN SOUTHWEST
AS A COLD FRONT SWEEPS AROUND THE BASE OF THE EXITING LOW PRESSURE.
SMALL CRAFT ADVISORIES WILL CONTINUE INTO MONDAY. WHILE A FEW GUSTS
MAY APPROACH GALE FORCE...THE MARINE LAYER LOOKS TO BE FAIRLY STABLE
WHICH WILL LIMIT THIS POTENTIAL. WINDS WILL SUBSIDE TO SOME EXTENT
FROM MONDAY NIGHT INTO TUESDAY AS THE LOW STALLS NEAR JAMES BAY AND
BEGINS TO SLOWLY WEAKEN.

&&

.AVIATION...ISSUED 159 PM EDT SUN APR 19 2015

LEAD ARC OF WARM ADVECTION LIFTING THROUGH THE SOUTHERN TAF SITES
AT TAF ISSUANCE TIME WILL CONTINUE TO PUSH NORTHWARD DURING THE
AFTERNOON HOURS. PROXIMITY TO LIGHTNING STRIKES LEADING INTO THE
TAFS NECESSITATED A SHORT DURATION TEMPO FOR POSSIBLE THUNDER.
LESSENING DEPTH TO UNSTABLE POCKET UP NORTH PRECLUDE A MENTION AT
THE NORTHERN TAF SITES. QUIET CONDITIONS EXPECTED DURING THE MID
AFTERNOON HOURS BEFORE MAIN BAND OF SYNOPTIC FORCING LIFTS INTO
SOUTHEASTERN MICHIGAN AFTER 21Z. DEPTH OF MOISTURE...LOW STABILITY
AND POTENTIAL FOR MESOSCALE AUGMENTATION OF LARGER SCALE FORCING
BRINGS A POTENTIAL FOR PERIODS OF HEAVY RAINFALL THIS EVENING FOR
FAR SOUTHEASTERN MICHIGAN. CONFIDENCE IS HIGH FOR IFR CONDITIONS
TONIGHT THROUGH DAYBREAK.

FOR DTW...TEMPO GROUP EXISTS THE FIRST HOUR OF THE TAF FORECAST
FOR ARC OF SHOWERS AND POSSIBLE RUMBLE OF THUNDER ROLLING THROUGH
THE TERMINALS. QUIET MID AFTERNOON PERIOD BEFORE CONDITIONS
DETERIORATE RAPIDLY AFTER 21Z. THE POTENTIAL EXISTS FOR A PERIOD
OF HEAVY RAINFALL THIS EVENING...BEFORE IFR CONDITIONS SETTLE IN
THROUGH DAYBREAK.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CIGS FALLING BELOW 5KFT LATE THIS AFTERNOON.

* LOW CONFIDENCE IN THUNDERSTORMS.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR LHZ441>443.

     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 8 PM EDT MONDAY FOR
     LHZ421-422.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR LEZ444.

&&

$$

SHORT TERM...CB
LONG TERM....DG/SS
MARINE.......DG
AVIATION.....CB


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).



000
FXUS63 KDTX 191956
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
356 PM EDT SUN APR 19 2015

.SHORT TERM...TONIGHT

THE ARC OF SHOWER ACTIVITY FORCED ON AN INITIAL SURGE/GRADIENT OF
850-700MB MOISTURE HAS STRUGGLED FROM A VIGOR PERSPECTIVE DUE TO A
LACK OF INSTABILITY. WITH SHOWERS WORKING UP THE FRONTAL SLOPE AS IT
TRACKS NORTHWARD...EXPECT THE WEAK NATURE TO CONTINUE.

THE MAIN BAND OF SYNOPTIC FORCING AND WIDESPREAD RAIN ACTIVITY WILL
LIFT ACROSS THE OHIO AND MICHIGAN BORDER AROUND 21Z. REGIONAL MOSAIC
AS OF 19Z... SHOWS THE MIDLEVELS SATURATING SOUTH OF TOLEDO. REALLY
A TREMENDOUS AMOUNT OF SYNOPTIC SCALE SUPPORT FOR LIFT AND
PRECIPITATION GENERATION TONIGHT AS SOUTHEASTERN MICHIGAN REMAINS
FAVORABLY POSITIONED AHEAD OF A HIGH AMPLITUDE WARM SECTOR
STRUCTURE AND OPTIMAL WARM AIR ADVECTION. EVERYTHING APPEARS TO BE
LINING UP FROM A FORCING STANDPOINT FOR A FAVORABLE PERIOD OF
WIDESPREAD RAIN INCLUDING A POTENTIAL FOR HEAVY RAINFALL.
SPECIFICALLY...LARGE BULLSEYE OF 1000-500MB HEIGHT FALLS...LINKAGE
OF RIGHT NOSE OF LOW LEVEL JET AXIS WITH RIGHT ENTRANCE REGION
DYNAMICS ALOFT...AND A DIRECT HIT FROM A SECONDARY VORTICITY
MAXIMUM. NWP SUPPORTS THIS SECONDARY VORTICITY MAXIMUM BECOMING
ORGANIZED/STRENGTHENING NEAR LOUISVILLE NOW AND LIFTING INTO FAR
SOUTHEASTERN MICHIGAN BETWEEN 00-03Z. NAM REALLY BITES ON THIS
FEATURE SHOWING DEPICTIONS OF A PSEUDO SHARS TYPE RESPONSE AND
HIGH AMOUNTS OF 3HR QPF. BROAD NATIONAL MOSAIC OF REFLECTIVITY
ALONG WITH SATELLITE IMAGERY OF CLEARING/DESTABILIZING STRAIGHT
INTO CENTRAL KENTUCKY SUPPORTS THIS STRONG SOLUTION OF THE
SECONDARY VORTICITY MAXIMUM. THUS...THE EARLIER FORECAST OF
FORECASTING QPF AMOUNTS OF UPWARDS OF 1.00 INCH FOR FAR
SOUTHEASTERN MICHIGAN INCLUDING THE DETROIT METRO APPEARS
REASONABLE. THERE AT LEAST REMAINS SOME POTENTIAL THAT THIS DRY
AIR/SLOT COULD WORK NORTHWARD AT A CRITICAL TRAJECTORY AND CAUSE
HEAVY PRECIPITATION TO DEFLECT AWAY FROM THE CWA. CONFIDENCE IN
PROJECTING THAT OUT IS LOW. WHILE FORECASTED QPF AMOUNTS ARE
RELATIVELY HIGH FROM AN EVENT STANDPOINT...THE STEADY NORTHWARD
PROGRESSION OF SHOWERS/EMBEDDED THUNDER WILL LIMIT THE CONCERN FOR
FLOODING.

&&

.LONG TERM...

STRONG LOW PRESSURE WILL CONTINUE TO DEEPEN AS IT LIFTS NORTHWARD
THROUGH NORTHERN LOWER MICHIGAN INTO ONTARIO ON MONDAY. MODELS HAVE
TRENDED SLIGHTLY SLOWLY AND FURTHER WEST WITH THE TRACK OF THIS
SYSTEM...AND THIS WILL MOSTLY LIKELY HAVE SOME NOTABLE IMPLICATIONS
TO THE GOING FORECAST. AS SUCH...HAVE MADE A FEW ADJUSTMENTS FOR
THIS PACKAGE.

THE "NEW" CONSENSUS TRACK FORECAST WILL ESSENTIALLY DELAY THE COLD
FRONTAL PASSAGE THROUGH THE AREA UNTIL LATE AFTERNOON AND ALLOW FOR
TEMPERATURES TO CLIMB WELL INTO THE 60S OVER A GOOD PORTION OF THE
AREA. THIS...IN TURN...WILL ALLOW FOR SOME DESTABILIZATION AS SBCAPE
VALUES CLIMB TO AROUND 500 J/KG BY AFTERNOON. THIS SHOULD ALLOW FOR
MORE VIGOROUS CONVECTION ALONG THE COLD FRONT WITH THE POTENTIAL FOR
HAIL INCREASING AS FREEZING LEVELS DROP BELOW 7000-8000 FEET AS COLD
AIR WRAP AROUND THE UPPER CIRCULATION.

IN ADDITION...THIS ACTIVITY WILL LIKELY PRODUCE SOME GUSTY WINDS AS
DEEP SWATH OF 35 TO 40 KT SOUTHWEST FLOW OVERSPREADS THE AREA. EVEN
OUTSIDE OF STORMS...WIND GUSTS WILL LIKELY REACH 35 MPH AT TIMES BY
AFTERNOON AND HAVE UPPED THE OVERALL FORECAST WINDS A FAIR AMOUNT.
WHILE WIDESPREAD STRONG STORMS ARE PROBABLY NOT TOO LIKELY...A FEW
WILL CERTAINLY BECOME A BIT ROBUST AS FORCING ALONG THE COLD FRONT
HELPS FOCUS THE MARGINAL INSTABILITY THAT IS ABLE TO BUILD OVER
PARTS OF THE AREA.

CONDITIONS WILL QUIET FROM MID EVENING INTO TUESDAY AS THE LOW LIFTS
TO NEAR JAMES BAY AND STALLS. THAT SAID...CONDITIONS WILL REMAIN
RATHER UNSETTLED INTO THE TUESDAY AND TUESDAY NIGHT PERIOD AS THIS
LOW ONLY GRADUALLY WEAKENS. EXPECT COOLER TEMPERATURES AND CONTINUE
GUSTY WINDS WITH SCATTERED RAIN SHOWERS DOTTING THE REGION...MAINLY
IN THE TUESDAY AFTERNOON PERIOD DURING THE DIURNAL TEMPERATURE AND
INSTABILITY MAX. DOWNSLOPING WEST/SOUTHWEST FLOW SHOULD ALLOW METRO
DETROIT AND SURROUNDING AREAS TO CLIMB INTO THE MID 50S DESPITE THE
MUCH COLDER AIRMASS...BUT STILL EXPECT LOWS WELL INTO THE 30S BY
TUESDAY NIGHT AS THE COLD AIRMASS DEEPENS OVER THE AREA.

EXTENDED FORECAST STARTING WEDNESDAY AND INTO NEXT WEEKEND WILL BE
RELATIVELY QUIET AS FAR AS PRECIPITATION GOES WITH BELOW NORMAL
TEMPERATURES.  COOLER AIR WILL CONTINUE TO FILTER INTO THE REGION AS
THE GREAT LAKES RESIDES IN THE PERSISTENT LONGWAVE TROUGHING.  WHILE
THERE WILL BE SLIGHT PRECIPITATION CHANCES WHILE THE REGION RESIDES
IN THE TROUGH...THE CAVEAT IS THE LACK OF MOISTURE THAT WILL BE
AVAILABLE.  RIDGING DOES NOT LOOK TO START BUILDING INTO THE WESTERN
GREAT LAKES REGION UNTIL THE END OF THE FORECAST PERIOD.

&&

.MARINE...

EAST FLOW WILL GRADUALLY BECOME SOUTHEAST TONIGHT AS DEEPENING LOW
PRESSURE PUSHES A WARM FRONT THROUGH THE AREA. DURING THIS TIME
FRAME...EXPECT STEADILY INCREASING WIND SPEEDS WHICH WILL ALLOW
WAVES TO BUILD. AS THIS LOW PASSES INTO THE NORTHERN GREAT LAKES
MONDAY...WINDS REMAIN GUSTY AND VEER TO THE SOUTH AND THEN SOUTHWEST
AS A COLD FRONT SWEEPS AROUND THE BASE OF THE EXITING LOW PRESSURE.
SMALL CRAFT ADVISORIES WILL CONTINUE INTO MONDAY. WHILE A FEW GUSTS
MAY APPROACH GALE FORCE...THE MARINE LAYER LOOKS TO BE FAIRLY STABLE
WHICH WILL LIMIT THIS POTENTIAL. WINDS WILL SUBSIDE TO SOME EXTENT
FROM MONDAY NIGHT INTO TUESDAY AS THE LOW STALLS NEAR JAMES BAY AND
BEGINS TO SLOWLY WEAKEN.

&&

.AVIATION...ISSUED 159 PM EDT SUN APR 19 2015

LEAD ARC OF WARM ADVECTION LIFTING THROUGH THE SOUTHERN TAF SITES
AT TAF ISSUANCE TIME WILL CONTINUE TO PUSH NORTHWARD DURING THE
AFTERNOON HOURS. PROXIMITY TO LIGHTNING STRIKES LEADING INTO THE
TAFS NECESSITATED A SHORT DURATION TEMPO FOR POSSIBLE THUNDER.
LESSENING DEPTH TO UNSTABLE POCKET UP NORTH PRECLUDE A MENTION AT
THE NORTHERN TAF SITES. QUIET CONDITIONS EXPECTED DURING THE MID
AFTERNOON HOURS BEFORE MAIN BAND OF SYNOPTIC FORCING LIFTS INTO
SOUTHEASTERN MICHIGAN AFTER 21Z. DEPTH OF MOISTURE...LOW STABILITY
AND POTENTIAL FOR MESOSCALE AUGMENTATION OF LARGER SCALE FORCING
BRINGS A POTENTIAL FOR PERIODS OF HEAVY RAINFALL THIS EVENING FOR
FAR SOUTHEASTERN MICHIGAN. CONFIDENCE IS HIGH FOR IFR CONDITIONS
TONIGHT THROUGH DAYBREAK.

FOR DTW...TEMPO GROUP EXISTS THE FIRST HOUR OF THE TAF FORECAST
FOR ARC OF SHOWERS AND POSSIBLE RUMBLE OF THUNDER ROLLING THROUGH
THE TERMINALS. QUIET MID AFTERNOON PERIOD BEFORE CONDITIONS
DETERIORATE RAPIDLY AFTER 21Z. THE POTENTIAL EXISTS FOR A PERIOD
OF HEAVY RAINFALL THIS EVENING...BEFORE IFR CONDITIONS SETTLE IN
THROUGH DAYBREAK.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CIGS FALLING BELOW 5KFT LATE THIS AFTERNOON.

* LOW CONFIDENCE IN THUNDERSTORMS.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR LHZ441>443.

     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 8 PM EDT MONDAY FOR
     LHZ421-422.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR LEZ444.

&&

$$

SHORT TERM...CB
LONG TERM....DG/SS
MARINE.......DG
AVIATION.....CB


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).




000
FXUS63 KGRR 191929
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
329 PM EDT SUN APR 19 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE

.SYNOPSIS...
ISSUED AT 258 PM EDT SUN APR 19 2015

A MAJOR CHANGE IN THE OVERALL WEATHER PATTERN IS ABOUT TO BEGIN. A
STRONG AND DEEPENING LOW PRESSURE SYSTEM WILL TRACK NORTHWARD
THROUGH WESTERN LOWER MICHIGAN TONIGHT BRINGING RAIN THAT MAY BE
HEAVY AT TIMES EARLY TONIGHT. AFTER THE SYSTEM MOVES NORTH OF THE
AREA LATER TONIGHT THE RAIN WILL DIMINISH TO SHOWERS BUT IT WILL
BE BREEZY. THEN SHOWERS AND BREEZY CONDITIONS WILL CONTINUE INTO
TUESDAY. BY TUESDAY NIGHT IT WILL GET COLD ENOUGH FOR SNOW TO MIX
WITH THE RAIN. THAT WILL CONTINUE INTO THURSDAY. IT WILL BE MUCH
COOLER THROUGH THIS ENTIRE PERIOD WITH HIGHS TUESDAY THROUGH
THURSDAY IN THE 40S AND LOWS NEAR FREEZING.


&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 258 PM EDT SUN APR 19 2015

THE PRIMARY ISSUE IS THE RAIN TONIGHT...THEN WINDY AND SHOWERS
MONDAY INTO TUESDAY. THERE IS A GOOD CHANCE OF MEASURABLE SNOW
OVER NORTHERN SECTIONS TUESDAY NIGHT.

THE DEEPENING STORM SYSTEM WILL TRACK THROUGH WESTERN LOWER
MICHIGAN TONIGHT BRINGING A PERIOD OF MODERATE TO HEAVY RAIN THAT
WILL LAST AROUND 6 HOURS IN ANY ONE PLACE. IT WILL BE BREEZY AT
FIRST BUT WINDS WILL DIMINISH TOWARD MIDNIGHT AS THE SURFACE LOW
MOVES THROUGH THE AREA.

THE RAIN EVENT TONIGHT REMAINS WELL SUPPORTED BY ALL THE MODELS.
THERE IS SOME ISSUE AS TO WHERE THE HEAVIEST RAIN WILL ACTUALLY
FALL BUT ALL AREAS GET AT LEAST A THIRD OF AN INCH AND MOST AREAS
SHOULD GET MORE THAN A HALF INCH OF RAIN TONIGHT. THIS IS ALL THE
RESULT OF UPPER WAVE THAT GOES NEGATIVE TILT OVER SOUTHWEST
MICHIGAN TONIGHT. THAT CAUSES THE SURFACE LOW TO TRACK NORTHWARD
AND DEEPEN RAPIDLY. ALSO THIS RESULTS IN A STRONG LOW LEVEL JET
(60 KNOTS)... STRONG 1000 TO 850 MOISTURE CONVERGENCE AMIED AT
SOUTHWEST LOWER MICHIGAN THIS EVENING AND CONDENSATION PRESSURE
DEFICITS NEAR ZERO MB THIS EVENING. THERE IS ALSO 40 KNOT OF WIND
PERPENDICULAR TO THE ISOTROPIC SURFACES EARLY TONIGHT... AND WE
CAN ALL ADD TO THAT PRECIPITATION WATER VALUES (1.4") NEAR 2
STANDARD DEVIATIONS FROM NORMAL AND MIXING RATIOS RISING TO NEAR 8
G/KG FROM UNDER 2 G/KG THIS MORNING. THERE IS ALSO A ZONE OF
STRONG MID-LEVEL FGEN JUST AHEAD OF THE SYSTEM AS IT MOVES THROUGH
SOUTHWEST MICHIGAN TONIGHT. BOTTOM LINE... IT WOULD BE HARD TO
IMAGINE WE WILL NOT GET RAIN OVERNIGHT.

ONCE THE LOW PASSES US THE SIGNIFICANT RAINFALL WILL END. HOWEVER
THE SECONDARY COLD FRONT AND TRAILING NORTHERN STREAM WAVE WILL
BRING ANOTHER PERIOD OF SHOWERS TO THE AREA MIDDAY MONDAY INTO
EARLY EVENING. THAT BRINGS IN THE TRULY COLDER AIR.

MONDAY NIGHT WE MAY SEE A BREAK IN THE SHOWERS EARLY ON BUT THEN
THE WRAP AROUND MOISTURE MOVES IN AND WE SEE SHOWERS THAT MAY MIX
WITH AN CHANGE TO SNOW SHOWERS BY TUESDAY NIGHT. BY THE WAY THE
SPC SOUNDING CLIMATOLOGY SHOWS THE RECORD LOW 850 TEMPERATURE FOR
THE DTX SOUNDING TO BE -12C ON THE 22ND. THE ECWMF SHOWS -9.8C AT
2 PM WEDNESDAY NEAR GRR. TO SAY THE LEAST...IT WILL GET COLDER
THIS COMING WEEK!


.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

UNSEASONABLY COLD WEATHER IS ANTICIPATED WEDNESDAY AND THURSDAY WITH
DEEP CYCLONIC FLOW AND COLD AIR ADVECTION WITH THE UPPER LEVEL LOW
STILL IN PLACE OVER THE NORTHERN GREAT LAKES REGION. SCATTERED RAIN
SHOWERS WILL CONTINUE AND MAY BE MIXED AT TIMES WITH WET SNOW FLAKES
ESPECIALLY OVER RELATIVELY HIGHER ELEVATIONS OF OUR NORTHERN FCST
AREA.

TEMPERATURES SHOULD MODERATE SLIGHTLY FRIDAY THROUGH THE WEEKEND BUT
WILL STILL AVERAGE SEVERAL DEGREES BELOW NORMAL. THIS AS A SFC RIDGE
BUILDS IN AND AS THE UPPER LEVEL LOW MOVES MUCH FURTHER EAST TO THE
NEW ENGLAND REGION BY THEN. THE RIDGE WILL BRING FAIR AND SEASONABLY
COOL WEATHER FRIDAY THROUGH SUNDAY.



&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY)
ISSUED AT 1215 PM EDT SUN APR 19 2015

VFR CONDITIONS WILL CONTINUE THROUGH MID AFTERNOON. CIGS WILL LOWER
AS RAIN MOVES IN FROM SOUTH TO NORTH LATE THIS AFTERNOON AND EARLY
EVENING. PRIMARILY MVFR CONDITIONS ARE ANTICIPATED THIS EVENING AND
CONDITIONS WILL DETERIORATE FURTHER TO IFR/LIFR OVERNIGHT DUE TO
LOWERING CIGS AND SHOWERS.

WINDS WILL REMAIN STRONG/GUSTY OUT OF THE EAST THIS AFTERNOON AND
EVENING BEFORE VEERING TO THE SOUTHWEST VERY LATE TONIGHT. IFR/LIFR
CONDITIONS WILL CONTINUE THROUGH MONDAY MORNING BEFORE IMPROVING
SLOWLY TO MAINLY MVFR MONDAY AFTERNOON.


&&

.MARINE...
ISSUED AT 258 PM EDT SUN APR 19 2015

I EXTENDED THE SCA THROUGH TUESDAY AFTERNOON FOR THE ALL THE ZONES
FROM WHITEHALL SOUTH ( NORTH OF THERE WINDS WILL NOT BE AS STRONG
OVERNIGHT). AFTER THE SURFACE LOW MOVES NORTH OF MUSKEGON WINDS WILL
INCREASE TO 30 KNOTS FROM THE SOUTHWEST THEN I EXPECT 15 TO 25
KNOT WINDS MONDAY INTO TUESDAY. AS THE COLD AIR COMES IN WAVES
WILL BUILD SO WE WILL LIKELY NEED A SCA FOR THE NORTHERN TWO ZONE
GROUPS MONDAY NIGHT AND TUESDAY.

&&

.HYDROLOGY...
ISSUED AT 1114 AM EDT SUN APR 19 2015

PERIODS OF RAIN ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON AND
AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. THE LIGHTER VARIETY OF
PRECIPITION MAY EXTENT INTO MIDWEEK. THOUGH WE WILL SEE A DECENT SOIL
SOAKING IT SHOULD NOT BE SUBSTANTIAL ENOUGH TO CREATE FLOODING
CONCERNS. GRADUAL BUT MINOR RISES ARE LIKELY...SUSPECTING THAT
THIS WOULD STAY WITHIN BANKS FOR MOST LOCATIONS. I WOULD NOT RULE
OUT A COUPLE OF SITES FLIRTING WITH ADVISORY STAGE AS WE GO INTO
TUESDAY...ESPECIALLY IF ANY MODERATE RAINFALL IS MORE PERSISTENT
WITH THE FIRST COUPLE OF ROUNDS OF MOISTURE. OTHERWISE...AREA
RIVERS ARE WELL BEHAVED THROUGH THE PERIOD.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...LAURENS
HYDROLOGY...JAM
MARINE...WDM






000
FXUS63 KGRR 191929
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
329 PM EDT SUN APR 19 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE

.SYNOPSIS...
ISSUED AT 258 PM EDT SUN APR 19 2015

A MAJOR CHANGE IN THE OVERALL WEATHER PATTERN IS ABOUT TO BEGIN. A
STRONG AND DEEPENING LOW PRESSURE SYSTEM WILL TRACK NORTHWARD
THROUGH WESTERN LOWER MICHIGAN TONIGHT BRINGING RAIN THAT MAY BE
HEAVY AT TIMES EARLY TONIGHT. AFTER THE SYSTEM MOVES NORTH OF THE
AREA LATER TONIGHT THE RAIN WILL DIMINISH TO SHOWERS BUT IT WILL
BE BREEZY. THEN SHOWERS AND BREEZY CONDITIONS WILL CONTINUE INTO
TUESDAY. BY TUESDAY NIGHT IT WILL GET COLD ENOUGH FOR SNOW TO MIX
WITH THE RAIN. THAT WILL CONTINUE INTO THURSDAY. IT WILL BE MUCH
COOLER THROUGH THIS ENTIRE PERIOD WITH HIGHS TUESDAY THROUGH
THURSDAY IN THE 40S AND LOWS NEAR FREEZING.


&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 258 PM EDT SUN APR 19 2015

THE PRIMARY ISSUE IS THE RAIN TONIGHT...THEN WINDY AND SHOWERS
MONDAY INTO TUESDAY. THERE IS A GOOD CHANCE OF MEASURABLE SNOW
OVER NORTHERN SECTIONS TUESDAY NIGHT.

THE DEEPENING STORM SYSTEM WILL TRACK THROUGH WESTERN LOWER
MICHIGAN TONIGHT BRINGING A PERIOD OF MODERATE TO HEAVY RAIN THAT
WILL LAST AROUND 6 HOURS IN ANY ONE PLACE. IT WILL BE BREEZY AT
FIRST BUT WINDS WILL DIMINISH TOWARD MIDNIGHT AS THE SURFACE LOW
MOVES THROUGH THE AREA.

THE RAIN EVENT TONIGHT REMAINS WELL SUPPORTED BY ALL THE MODELS.
THERE IS SOME ISSUE AS TO WHERE THE HEAVIEST RAIN WILL ACTUALLY
FALL BUT ALL AREAS GET AT LEAST A THIRD OF AN INCH AND MOST AREAS
SHOULD GET MORE THAN A HALF INCH OF RAIN TONIGHT. THIS IS ALL THE
RESULT OF UPPER WAVE THAT GOES NEGATIVE TILT OVER SOUTHWEST
MICHIGAN TONIGHT. THAT CAUSES THE SURFACE LOW TO TRACK NORTHWARD
AND DEEPEN RAPIDLY. ALSO THIS RESULTS IN A STRONG LOW LEVEL JET
(60 KNOTS)... STRONG 1000 TO 850 MOISTURE CONVERGENCE AMIED AT
SOUTHWEST LOWER MICHIGAN THIS EVENING AND CONDENSATION PRESSURE
DEFICITS NEAR ZERO MB THIS EVENING. THERE IS ALSO 40 KNOT OF WIND
PERPENDICULAR TO THE ISOTROPIC SURFACES EARLY TONIGHT... AND WE
CAN ALL ADD TO THAT PRECIPITATION WATER VALUES (1.4") NEAR 2
STANDARD DEVIATIONS FROM NORMAL AND MIXING RATIOS RISING TO NEAR 8
G/KG FROM UNDER 2 G/KG THIS MORNING. THERE IS ALSO A ZONE OF
STRONG MID-LEVEL FGEN JUST AHEAD OF THE SYSTEM AS IT MOVES THROUGH
SOUTHWEST MICHIGAN TONIGHT. BOTTOM LINE... IT WOULD BE HARD TO
IMAGINE WE WILL NOT GET RAIN OVERNIGHT.

ONCE THE LOW PASSES US THE SIGNIFICANT RAINFALL WILL END. HOWEVER
THE SECONDARY COLD FRONT AND TRAILING NORTHERN STREAM WAVE WILL
BRING ANOTHER PERIOD OF SHOWERS TO THE AREA MIDDAY MONDAY INTO
EARLY EVENING. THAT BRINGS IN THE TRULY COLDER AIR.

MONDAY NIGHT WE MAY SEE A BREAK IN THE SHOWERS EARLY ON BUT THEN
THE WRAP AROUND MOISTURE MOVES IN AND WE SEE SHOWERS THAT MAY MIX
WITH AN CHANGE TO SNOW SHOWERS BY TUESDAY NIGHT. BY THE WAY THE
SPC SOUNDING CLIMATOLOGY SHOWS THE RECORD LOW 850 TEMPERATURE FOR
THE DTX SOUNDING TO BE -12C ON THE 22ND. THE ECWMF SHOWS -9.8C AT
2 PM WEDNESDAY NEAR GRR. TO SAY THE LEAST...IT WILL GET COLDER
THIS COMING WEEK!


.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

UNSEASONABLY COLD WEATHER IS ANTICIPATED WEDNESDAY AND THURSDAY WITH
DEEP CYCLONIC FLOW AND COLD AIR ADVECTION WITH THE UPPER LEVEL LOW
STILL IN PLACE OVER THE NORTHERN GREAT LAKES REGION. SCATTERED RAIN
SHOWERS WILL CONTINUE AND MAY BE MIXED AT TIMES WITH WET SNOW FLAKES
ESPECIALLY OVER RELATIVELY HIGHER ELEVATIONS OF OUR NORTHERN FCST
AREA.

TEMPERATURES SHOULD MODERATE SLIGHTLY FRIDAY THROUGH THE WEEKEND BUT
WILL STILL AVERAGE SEVERAL DEGREES BELOW NORMAL. THIS AS A SFC RIDGE
BUILDS IN AND AS THE UPPER LEVEL LOW MOVES MUCH FURTHER EAST TO THE
NEW ENGLAND REGION BY THEN. THE RIDGE WILL BRING FAIR AND SEASONABLY
COOL WEATHER FRIDAY THROUGH SUNDAY.



&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY)
ISSUED AT 1215 PM EDT SUN APR 19 2015

VFR CONDITIONS WILL CONTINUE THROUGH MID AFTERNOON. CIGS WILL LOWER
AS RAIN MOVES IN FROM SOUTH TO NORTH LATE THIS AFTERNOON AND EARLY
EVENING. PRIMARILY MVFR CONDITIONS ARE ANTICIPATED THIS EVENING AND
CONDITIONS WILL DETERIORATE FURTHER TO IFR/LIFR OVERNIGHT DUE TO
LOWERING CIGS AND SHOWERS.

WINDS WILL REMAIN STRONG/GUSTY OUT OF THE EAST THIS AFTERNOON AND
EVENING BEFORE VEERING TO THE SOUTHWEST VERY LATE TONIGHT. IFR/LIFR
CONDITIONS WILL CONTINUE THROUGH MONDAY MORNING BEFORE IMPROVING
SLOWLY TO MAINLY MVFR MONDAY AFTERNOON.


&&

.MARINE...
ISSUED AT 258 PM EDT SUN APR 19 2015

I EXTENDED THE SCA THROUGH TUESDAY AFTERNOON FOR THE ALL THE ZONES
FROM WHITEHALL SOUTH ( NORTH OF THERE WINDS WILL NOT BE AS STRONG
OVERNIGHT). AFTER THE SURFACE LOW MOVES NORTH OF MUSKEGON WINDS WILL
INCREASE TO 30 KNOTS FROM THE SOUTHWEST THEN I EXPECT 15 TO 25
KNOT WINDS MONDAY INTO TUESDAY. AS THE COLD AIR COMES IN WAVES
WILL BUILD SO WE WILL LIKELY NEED A SCA FOR THE NORTHERN TWO ZONE
GROUPS MONDAY NIGHT AND TUESDAY.

&&

.HYDROLOGY...
ISSUED AT 1114 AM EDT SUN APR 19 2015

PERIODS OF RAIN ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON AND
AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. THE LIGHTER VARIETY OF
PRECIPITION MAY EXTENT INTO MIDWEEK. THOUGH WE WILL SEE A DECENT SOIL
SOAKING IT SHOULD NOT BE SUBSTANTIAL ENOUGH TO CREATE FLOODING
CONCERNS. GRADUAL BUT MINOR RISES ARE LIKELY...SUSPECTING THAT
THIS WOULD STAY WITHIN BANKS FOR MOST LOCATIONS. I WOULD NOT RULE
OUT A COUPLE OF SITES FLIRTING WITH ADVISORY STAGE AS WE GO INTO
TUESDAY...ESPECIALLY IF ANY MODERATE RAINFALL IS MORE PERSISTENT
WITH THE FIRST COUPLE OF ROUNDS OF MOISTURE. OTHERWISE...AREA
RIVERS ARE WELL BEHAVED THROUGH THE PERIOD.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...LAURENS
HYDROLOGY...JAM
MARINE...WDM







000
FXUS63 KGRR 191929
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
329 PM EDT SUN APR 19 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE

.SYNOPSIS...
ISSUED AT 258 PM EDT SUN APR 19 2015

A MAJOR CHANGE IN THE OVERALL WEATHER PATTERN IS ABOUT TO BEGIN. A
STRONG AND DEEPENING LOW PRESSURE SYSTEM WILL TRACK NORTHWARD
THROUGH WESTERN LOWER MICHIGAN TONIGHT BRINGING RAIN THAT MAY BE
HEAVY AT TIMES EARLY TONIGHT. AFTER THE SYSTEM MOVES NORTH OF THE
AREA LATER TONIGHT THE RAIN WILL DIMINISH TO SHOWERS BUT IT WILL
BE BREEZY. THEN SHOWERS AND BREEZY CONDITIONS WILL CONTINUE INTO
TUESDAY. BY TUESDAY NIGHT IT WILL GET COLD ENOUGH FOR SNOW TO MIX
WITH THE RAIN. THAT WILL CONTINUE INTO THURSDAY. IT WILL BE MUCH
COOLER THROUGH THIS ENTIRE PERIOD WITH HIGHS TUESDAY THROUGH
THURSDAY IN THE 40S AND LOWS NEAR FREEZING.


&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 258 PM EDT SUN APR 19 2015

THE PRIMARY ISSUE IS THE RAIN TONIGHT...THEN WINDY AND SHOWERS
MONDAY INTO TUESDAY. THERE IS A GOOD CHANCE OF MEASURABLE SNOW
OVER NORTHERN SECTIONS TUESDAY NIGHT.

THE DEEPENING STORM SYSTEM WILL TRACK THROUGH WESTERN LOWER
MICHIGAN TONIGHT BRINGING A PERIOD OF MODERATE TO HEAVY RAIN THAT
WILL LAST AROUND 6 HOURS IN ANY ONE PLACE. IT WILL BE BREEZY AT
FIRST BUT WINDS WILL DIMINISH TOWARD MIDNIGHT AS THE SURFACE LOW
MOVES THROUGH THE AREA.

THE RAIN EVENT TONIGHT REMAINS WELL SUPPORTED BY ALL THE MODELS.
THERE IS SOME ISSUE AS TO WHERE THE HEAVIEST RAIN WILL ACTUALLY
FALL BUT ALL AREAS GET AT LEAST A THIRD OF AN INCH AND MOST AREAS
SHOULD GET MORE THAN A HALF INCH OF RAIN TONIGHT. THIS IS ALL THE
RESULT OF UPPER WAVE THAT GOES NEGATIVE TILT OVER SOUTHWEST
MICHIGAN TONIGHT. THAT CAUSES THE SURFACE LOW TO TRACK NORTHWARD
AND DEEPEN RAPIDLY. ALSO THIS RESULTS IN A STRONG LOW LEVEL JET
(60 KNOTS)... STRONG 1000 TO 850 MOISTURE CONVERGENCE AMIED AT
SOUTHWEST LOWER MICHIGAN THIS EVENING AND CONDENSATION PRESSURE
DEFICITS NEAR ZERO MB THIS EVENING. THERE IS ALSO 40 KNOT OF WIND
PERPENDICULAR TO THE ISOTROPIC SURFACES EARLY TONIGHT... AND WE
CAN ALL ADD TO THAT PRECIPITATION WATER VALUES (1.4") NEAR 2
STANDARD DEVIATIONS FROM NORMAL AND MIXING RATIOS RISING TO NEAR 8
G/KG FROM UNDER 2 G/KG THIS MORNING. THERE IS ALSO A ZONE OF
STRONG MID-LEVEL FGEN JUST AHEAD OF THE SYSTEM AS IT MOVES THROUGH
SOUTHWEST MICHIGAN TONIGHT. BOTTOM LINE... IT WOULD BE HARD TO
IMAGINE WE WILL NOT GET RAIN OVERNIGHT.

ONCE THE LOW PASSES US THE SIGNIFICANT RAINFALL WILL END. HOWEVER
THE SECONDARY COLD FRONT AND TRAILING NORTHERN STREAM WAVE WILL
BRING ANOTHER PERIOD OF SHOWERS TO THE AREA MIDDAY MONDAY INTO
EARLY EVENING. THAT BRINGS IN THE TRULY COLDER AIR.

MONDAY NIGHT WE MAY SEE A BREAK IN THE SHOWERS EARLY ON BUT THEN
THE WRAP AROUND MOISTURE MOVES IN AND WE SEE SHOWERS THAT MAY MIX
WITH AN CHANGE TO SNOW SHOWERS BY TUESDAY NIGHT. BY THE WAY THE
SPC SOUNDING CLIMATOLOGY SHOWS THE RECORD LOW 850 TEMPERATURE FOR
THE DTX SOUNDING TO BE -12C ON THE 22ND. THE ECWMF SHOWS -9.8C AT
2 PM WEDNESDAY NEAR GRR. TO SAY THE LEAST...IT WILL GET COLDER
THIS COMING WEEK!


.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

UNSEASONABLY COLD WEATHER IS ANTICIPATED WEDNESDAY AND THURSDAY WITH
DEEP CYCLONIC FLOW AND COLD AIR ADVECTION WITH THE UPPER LEVEL LOW
STILL IN PLACE OVER THE NORTHERN GREAT LAKES REGION. SCATTERED RAIN
SHOWERS WILL CONTINUE AND MAY BE MIXED AT TIMES WITH WET SNOW FLAKES
ESPECIALLY OVER RELATIVELY HIGHER ELEVATIONS OF OUR NORTHERN FCST
AREA.

TEMPERATURES SHOULD MODERATE SLIGHTLY FRIDAY THROUGH THE WEEKEND BUT
WILL STILL AVERAGE SEVERAL DEGREES BELOW NORMAL. THIS AS A SFC RIDGE
BUILDS IN AND AS THE UPPER LEVEL LOW MOVES MUCH FURTHER EAST TO THE
NEW ENGLAND REGION BY THEN. THE RIDGE WILL BRING FAIR AND SEASONABLY
COOL WEATHER FRIDAY THROUGH SUNDAY.



&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY)
ISSUED AT 1215 PM EDT SUN APR 19 2015

VFR CONDITIONS WILL CONTINUE THROUGH MID AFTERNOON. CIGS WILL LOWER
AS RAIN MOVES IN FROM SOUTH TO NORTH LATE THIS AFTERNOON AND EARLY
EVENING. PRIMARILY MVFR CONDITIONS ARE ANTICIPATED THIS EVENING AND
CONDITIONS WILL DETERIORATE FURTHER TO IFR/LIFR OVERNIGHT DUE TO
LOWERING CIGS AND SHOWERS.

WINDS WILL REMAIN STRONG/GUSTY OUT OF THE EAST THIS AFTERNOON AND
EVENING BEFORE VEERING TO THE SOUTHWEST VERY LATE TONIGHT. IFR/LIFR
CONDITIONS WILL CONTINUE THROUGH MONDAY MORNING BEFORE IMPROVING
SLOWLY TO MAINLY MVFR MONDAY AFTERNOON.


&&

.MARINE...
ISSUED AT 258 PM EDT SUN APR 19 2015

I EXTENDED THE SCA THROUGH TUESDAY AFTERNOON FOR THE ALL THE ZONES
FROM WHITEHALL SOUTH ( NORTH OF THERE WINDS WILL NOT BE AS STRONG
OVERNIGHT). AFTER THE SURFACE LOW MOVES NORTH OF MUSKEGON WINDS WILL
INCREASE TO 30 KNOTS FROM THE SOUTHWEST THEN I EXPECT 15 TO 25
KNOT WINDS MONDAY INTO TUESDAY. AS THE COLD AIR COMES IN WAVES
WILL BUILD SO WE WILL LIKELY NEED A SCA FOR THE NORTHERN TWO ZONE
GROUPS MONDAY NIGHT AND TUESDAY.

&&

.HYDROLOGY...
ISSUED AT 1114 AM EDT SUN APR 19 2015

PERIODS OF RAIN ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON AND
AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. THE LIGHTER VARIETY OF
PRECIPITION MAY EXTENT INTO MIDWEEK. THOUGH WE WILL SEE A DECENT SOIL
SOAKING IT SHOULD NOT BE SUBSTANTIAL ENOUGH TO CREATE FLOODING
CONCERNS. GRADUAL BUT MINOR RISES ARE LIKELY...SUSPECTING THAT
THIS WOULD STAY WITHIN BANKS FOR MOST LOCATIONS. I WOULD NOT RULE
OUT A COUPLE OF SITES FLIRTING WITH ADVISORY STAGE AS WE GO INTO
TUESDAY...ESPECIALLY IF ANY MODERATE RAINFALL IS MORE PERSISTENT
WITH THE FIRST COUPLE OF ROUNDS OF MOISTURE. OTHERWISE...AREA
RIVERS ARE WELL BEHAVED THROUGH THE PERIOD.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...LAURENS
HYDROLOGY...JAM
MARINE...WDM







000
FXUS63 KGRR 191929
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
329 PM EDT SUN APR 19 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE

.SYNOPSIS...
ISSUED AT 258 PM EDT SUN APR 19 2015

A MAJOR CHANGE IN THE OVERALL WEATHER PATTERN IS ABOUT TO BEGIN. A
STRONG AND DEEPENING LOW PRESSURE SYSTEM WILL TRACK NORTHWARD
THROUGH WESTERN LOWER MICHIGAN TONIGHT BRINGING RAIN THAT MAY BE
HEAVY AT TIMES EARLY TONIGHT. AFTER THE SYSTEM MOVES NORTH OF THE
AREA LATER TONIGHT THE RAIN WILL DIMINISH TO SHOWERS BUT IT WILL
BE BREEZY. THEN SHOWERS AND BREEZY CONDITIONS WILL CONTINUE INTO
TUESDAY. BY TUESDAY NIGHT IT WILL GET COLD ENOUGH FOR SNOW TO MIX
WITH THE RAIN. THAT WILL CONTINUE INTO THURSDAY. IT WILL BE MUCH
COOLER THROUGH THIS ENTIRE PERIOD WITH HIGHS TUESDAY THROUGH
THURSDAY IN THE 40S AND LOWS NEAR FREEZING.


&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 258 PM EDT SUN APR 19 2015

THE PRIMARY ISSUE IS THE RAIN TONIGHT...THEN WINDY AND SHOWERS
MONDAY INTO TUESDAY. THERE IS A GOOD CHANCE OF MEASURABLE SNOW
OVER NORTHERN SECTIONS TUESDAY NIGHT.

THE DEEPENING STORM SYSTEM WILL TRACK THROUGH WESTERN LOWER
MICHIGAN TONIGHT BRINGING A PERIOD OF MODERATE TO HEAVY RAIN THAT
WILL LAST AROUND 6 HOURS IN ANY ONE PLACE. IT WILL BE BREEZY AT
FIRST BUT WINDS WILL DIMINISH TOWARD MIDNIGHT AS THE SURFACE LOW
MOVES THROUGH THE AREA.

THE RAIN EVENT TONIGHT REMAINS WELL SUPPORTED BY ALL THE MODELS.
THERE IS SOME ISSUE AS TO WHERE THE HEAVIEST RAIN WILL ACTUALLY
FALL BUT ALL AREAS GET AT LEAST A THIRD OF AN INCH AND MOST AREAS
SHOULD GET MORE THAN A HALF INCH OF RAIN TONIGHT. THIS IS ALL THE
RESULT OF UPPER WAVE THAT GOES NEGATIVE TILT OVER SOUTHWEST
MICHIGAN TONIGHT. THAT CAUSES THE SURFACE LOW TO TRACK NORTHWARD
AND DEEPEN RAPIDLY. ALSO THIS RESULTS IN A STRONG LOW LEVEL JET
(60 KNOTS)... STRONG 1000 TO 850 MOISTURE CONVERGENCE AMIED AT
SOUTHWEST LOWER MICHIGAN THIS EVENING AND CONDENSATION PRESSURE
DEFICITS NEAR ZERO MB THIS EVENING. THERE IS ALSO 40 KNOT OF WIND
PERPENDICULAR TO THE ISOTROPIC SURFACES EARLY TONIGHT... AND WE
CAN ALL ADD TO THAT PRECIPITATION WATER VALUES (1.4") NEAR 2
STANDARD DEVIATIONS FROM NORMAL AND MIXING RATIOS RISING TO NEAR 8
G/KG FROM UNDER 2 G/KG THIS MORNING. THERE IS ALSO A ZONE OF
STRONG MID-LEVEL FGEN JUST AHEAD OF THE SYSTEM AS IT MOVES THROUGH
SOUTHWEST MICHIGAN TONIGHT. BOTTOM LINE... IT WOULD BE HARD TO
IMAGINE WE WILL NOT GET RAIN OVERNIGHT.

ONCE THE LOW PASSES US THE SIGNIFICANT RAINFALL WILL END. HOWEVER
THE SECONDARY COLD FRONT AND TRAILING NORTHERN STREAM WAVE WILL
BRING ANOTHER PERIOD OF SHOWERS TO THE AREA MIDDAY MONDAY INTO
EARLY EVENING. THAT BRINGS IN THE TRULY COLDER AIR.

MONDAY NIGHT WE MAY SEE A BREAK IN THE SHOWERS EARLY ON BUT THEN
THE WRAP AROUND MOISTURE MOVES IN AND WE SEE SHOWERS THAT MAY MIX
WITH AN CHANGE TO SNOW SHOWERS BY TUESDAY NIGHT. BY THE WAY THE
SPC SOUNDING CLIMATOLOGY SHOWS THE RECORD LOW 850 TEMPERATURE FOR
THE DTX SOUNDING TO BE -12C ON THE 22ND. THE ECWMF SHOWS -9.8C AT
2 PM WEDNESDAY NEAR GRR. TO SAY THE LEAST...IT WILL GET COLDER
THIS COMING WEEK!


.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

UNSEASONABLY COLD WEATHER IS ANTICIPATED WEDNESDAY AND THURSDAY WITH
DEEP CYCLONIC FLOW AND COLD AIR ADVECTION WITH THE UPPER LEVEL LOW
STILL IN PLACE OVER THE NORTHERN GREAT LAKES REGION. SCATTERED RAIN
SHOWERS WILL CONTINUE AND MAY BE MIXED AT TIMES WITH WET SNOW FLAKES
ESPECIALLY OVER RELATIVELY HIGHER ELEVATIONS OF OUR NORTHERN FCST
AREA.

TEMPERATURES SHOULD MODERATE SLIGHTLY FRIDAY THROUGH THE WEEKEND BUT
WILL STILL AVERAGE SEVERAL DEGREES BELOW NORMAL. THIS AS A SFC RIDGE
BUILDS IN AND AS THE UPPER LEVEL LOW MOVES MUCH FURTHER EAST TO THE
NEW ENGLAND REGION BY THEN. THE RIDGE WILL BRING FAIR AND SEASONABLY
COOL WEATHER FRIDAY THROUGH SUNDAY.



&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY)
ISSUED AT 1215 PM EDT SUN APR 19 2015

VFR CONDITIONS WILL CONTINUE THROUGH MID AFTERNOON. CIGS WILL LOWER
AS RAIN MOVES IN FROM SOUTH TO NORTH LATE THIS AFTERNOON AND EARLY
EVENING. PRIMARILY MVFR CONDITIONS ARE ANTICIPATED THIS EVENING AND
CONDITIONS WILL DETERIORATE FURTHER TO IFR/LIFR OVERNIGHT DUE TO
LOWERING CIGS AND SHOWERS.

WINDS WILL REMAIN STRONG/GUSTY OUT OF THE EAST THIS AFTERNOON AND
EVENING BEFORE VEERING TO THE SOUTHWEST VERY LATE TONIGHT. IFR/LIFR
CONDITIONS WILL CONTINUE THROUGH MONDAY MORNING BEFORE IMPROVING
SLOWLY TO MAINLY MVFR MONDAY AFTERNOON.


&&

.MARINE...
ISSUED AT 258 PM EDT SUN APR 19 2015

I EXTENDED THE SCA THROUGH TUESDAY AFTERNOON FOR THE ALL THE ZONES
FROM WHITEHALL SOUTH ( NORTH OF THERE WINDS WILL NOT BE AS STRONG
OVERNIGHT). AFTER THE SURFACE LOW MOVES NORTH OF MUSKEGON WINDS WILL
INCREASE TO 30 KNOTS FROM THE SOUTHWEST THEN I EXPECT 15 TO 25
KNOT WINDS MONDAY INTO TUESDAY. AS THE COLD AIR COMES IN WAVES
WILL BUILD SO WE WILL LIKELY NEED A SCA FOR THE NORTHERN TWO ZONE
GROUPS MONDAY NIGHT AND TUESDAY.

&&

.HYDROLOGY...
ISSUED AT 1114 AM EDT SUN APR 19 2015

PERIODS OF RAIN ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON AND
AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. THE LIGHTER VARIETY OF
PRECIPITION MAY EXTENT INTO MIDWEEK. THOUGH WE WILL SEE A DECENT SOIL
SOAKING IT SHOULD NOT BE SUBSTANTIAL ENOUGH TO CREATE FLOODING
CONCERNS. GRADUAL BUT MINOR RISES ARE LIKELY...SUSPECTING THAT
THIS WOULD STAY WITHIN BANKS FOR MOST LOCATIONS. I WOULD NOT RULE
OUT A COUPLE OF SITES FLIRTING WITH ADVISORY STAGE AS WE GO INTO
TUESDAY...ESPECIALLY IF ANY MODERATE RAINFALL IS MORE PERSISTENT
WITH THE FIRST COUPLE OF ROUNDS OF MOISTURE. OTHERWISE...AREA
RIVERS ARE WELL BEHAVED THROUGH THE PERIOD.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...LAURENS
HYDROLOGY...JAM
MARINE...WDM







000
FXUS63 KGRR 191929
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
329 PM EDT SUN APR 19 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE

.SYNOPSIS...
ISSUED AT 258 PM EDT SUN APR 19 2015

A MAJOR CHANGE IN THE OVERALL WEATHER PATTERN IS ABOUT TO BEGIN. A
STRONG AND DEEPENING LOW PRESSURE SYSTEM WILL TRACK NORTHWARD
THROUGH WESTERN LOWER MICHIGAN TONIGHT BRINGING RAIN THAT MAY BE
HEAVY AT TIMES EARLY TONIGHT. AFTER THE SYSTEM MOVES NORTH OF THE
AREA LATER TONIGHT THE RAIN WILL DIMINISH TO SHOWERS BUT IT WILL
BE BREEZY. THEN SHOWERS AND BREEZY CONDITIONS WILL CONTINUE INTO
TUESDAY. BY TUESDAY NIGHT IT WILL GET COLD ENOUGH FOR SNOW TO MIX
WITH THE RAIN. THAT WILL CONTINUE INTO THURSDAY. IT WILL BE MUCH
COOLER THROUGH THIS ENTIRE PERIOD WITH HIGHS TUESDAY THROUGH
THURSDAY IN THE 40S AND LOWS NEAR FREEZING.


&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 258 PM EDT SUN APR 19 2015

THE PRIMARY ISSUE IS THE RAIN TONIGHT...THEN WINDY AND SHOWERS
MONDAY INTO TUESDAY. THERE IS A GOOD CHANCE OF MEASURABLE SNOW
OVER NORTHERN SECTIONS TUESDAY NIGHT.

THE DEEPENING STORM SYSTEM WILL TRACK THROUGH WESTERN LOWER
MICHIGAN TONIGHT BRINGING A PERIOD OF MODERATE TO HEAVY RAIN THAT
WILL LAST AROUND 6 HOURS IN ANY ONE PLACE. IT WILL BE BREEZY AT
FIRST BUT WINDS WILL DIMINISH TOWARD MIDNIGHT AS THE SURFACE LOW
MOVES THROUGH THE AREA.

THE RAIN EVENT TONIGHT REMAINS WELL SUPPORTED BY ALL THE MODELS.
THERE IS SOME ISSUE AS TO WHERE THE HEAVIEST RAIN WILL ACTUALLY
FALL BUT ALL AREAS GET AT LEAST A THIRD OF AN INCH AND MOST AREAS
SHOULD GET MORE THAN A HALF INCH OF RAIN TONIGHT. THIS IS ALL THE
RESULT OF UPPER WAVE THAT GOES NEGATIVE TILT OVER SOUTHWEST
MICHIGAN TONIGHT. THAT CAUSES THE SURFACE LOW TO TRACK NORTHWARD
AND DEEPEN RAPIDLY. ALSO THIS RESULTS IN A STRONG LOW LEVEL JET
(60 KNOTS)... STRONG 1000 TO 850 MOISTURE CONVERGENCE AMIED AT
SOUTHWEST LOWER MICHIGAN THIS EVENING AND CONDENSATION PRESSURE
DEFICITS NEAR ZERO MB THIS EVENING. THERE IS ALSO 40 KNOT OF WIND
PERPENDICULAR TO THE ISOTROPIC SURFACES EARLY TONIGHT... AND WE
CAN ALL ADD TO THAT PRECIPITATION WATER VALUES (1.4") NEAR 2
STANDARD DEVIATIONS FROM NORMAL AND MIXING RATIOS RISING TO NEAR 8
G/KG FROM UNDER 2 G/KG THIS MORNING. THERE IS ALSO A ZONE OF
STRONG MID-LEVEL FGEN JUST AHEAD OF THE SYSTEM AS IT MOVES THROUGH
SOUTHWEST MICHIGAN TONIGHT. BOTTOM LINE... IT WOULD BE HARD TO
IMAGINE WE WILL NOT GET RAIN OVERNIGHT.

ONCE THE LOW PASSES US THE SIGNIFICANT RAINFALL WILL END. HOWEVER
THE SECONDARY COLD FRONT AND TRAILING NORTHERN STREAM WAVE WILL
BRING ANOTHER PERIOD OF SHOWERS TO THE AREA MIDDAY MONDAY INTO
EARLY EVENING. THAT BRINGS IN THE TRULY COLDER AIR.

MONDAY NIGHT WE MAY SEE A BREAK IN THE SHOWERS EARLY ON BUT THEN
THE WRAP AROUND MOISTURE MOVES IN AND WE SEE SHOWERS THAT MAY MIX
WITH AN CHANGE TO SNOW SHOWERS BY TUESDAY NIGHT. BY THE WAY THE
SPC SOUNDING CLIMATOLOGY SHOWS THE RECORD LOW 850 TEMPERATURE FOR
THE DTX SOUNDING TO BE -12C ON THE 22ND. THE ECWMF SHOWS -9.8C AT
2 PM WEDNESDAY NEAR GRR. TO SAY THE LEAST...IT WILL GET COLDER
THIS COMING WEEK!


.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

UNSEASONABLY COLD WEATHER IS ANTICIPATED WEDNESDAY AND THURSDAY WITH
DEEP CYCLONIC FLOW AND COLD AIR ADVECTION WITH THE UPPER LEVEL LOW
STILL IN PLACE OVER THE NORTHERN GREAT LAKES REGION. SCATTERED RAIN
SHOWERS WILL CONTINUE AND MAY BE MIXED AT TIMES WITH WET SNOW FLAKES
ESPECIALLY OVER RELATIVELY HIGHER ELEVATIONS OF OUR NORTHERN FCST
AREA.

TEMPERATURES SHOULD MODERATE SLIGHTLY FRIDAY THROUGH THE WEEKEND BUT
WILL STILL AVERAGE SEVERAL DEGREES BELOW NORMAL. THIS AS A SFC RIDGE
BUILDS IN AND AS THE UPPER LEVEL LOW MOVES MUCH FURTHER EAST TO THE
NEW ENGLAND REGION BY THEN. THE RIDGE WILL BRING FAIR AND SEASONABLY
COOL WEATHER FRIDAY THROUGH SUNDAY.



&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY)
ISSUED AT 1215 PM EDT SUN APR 19 2015

VFR CONDITIONS WILL CONTINUE THROUGH MID AFTERNOON. CIGS WILL LOWER
AS RAIN MOVES IN FROM SOUTH TO NORTH LATE THIS AFTERNOON AND EARLY
EVENING. PRIMARILY MVFR CONDITIONS ARE ANTICIPATED THIS EVENING AND
CONDITIONS WILL DETERIORATE FURTHER TO IFR/LIFR OVERNIGHT DUE TO
LOWERING CIGS AND SHOWERS.

WINDS WILL REMAIN STRONG/GUSTY OUT OF THE EAST THIS AFTERNOON AND
EVENING BEFORE VEERING TO THE SOUTHWEST VERY LATE TONIGHT. IFR/LIFR
CONDITIONS WILL CONTINUE THROUGH MONDAY MORNING BEFORE IMPROVING
SLOWLY TO MAINLY MVFR MONDAY AFTERNOON.


&&

.MARINE...
ISSUED AT 258 PM EDT SUN APR 19 2015

I EXTENDED THE SCA THROUGH TUESDAY AFTERNOON FOR THE ALL THE ZONES
FROM WHITEHALL SOUTH ( NORTH OF THERE WINDS WILL NOT BE AS STRONG
OVERNIGHT). AFTER THE SURFACE LOW MOVES NORTH OF MUSKEGON WINDS WILL
INCREASE TO 30 KNOTS FROM THE SOUTHWEST THEN I EXPECT 15 TO 25
KNOT WINDS MONDAY INTO TUESDAY. AS THE COLD AIR COMES IN WAVES
WILL BUILD SO WE WILL LIKELY NEED A SCA FOR THE NORTHERN TWO ZONE
GROUPS MONDAY NIGHT AND TUESDAY.

&&

.HYDROLOGY...
ISSUED AT 1114 AM EDT SUN APR 19 2015

PERIODS OF RAIN ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON AND
AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. THE LIGHTER VARIETY OF
PRECIPITION MAY EXTENT INTO MIDWEEK. THOUGH WE WILL SEE A DECENT SOIL
SOAKING IT SHOULD NOT BE SUBSTANTIAL ENOUGH TO CREATE FLOODING
CONCERNS. GRADUAL BUT MINOR RISES ARE LIKELY...SUSPECTING THAT
THIS WOULD STAY WITHIN BANKS FOR MOST LOCATIONS. I WOULD NOT RULE
OUT A COUPLE OF SITES FLIRTING WITH ADVISORY STAGE AS WE GO INTO
TUESDAY...ESPECIALLY IF ANY MODERATE RAINFALL IS MORE PERSISTENT
WITH THE FIRST COUPLE OF ROUNDS OF MOISTURE. OTHERWISE...AREA
RIVERS ARE WELL BEHAVED THROUGH THE PERIOD.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...LAURENS
HYDROLOGY...JAM
MARINE...WDM







000
FXUS63 KGRR 191929
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
329 PM EDT SUN APR 19 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE

.SYNOPSIS...
ISSUED AT 258 PM EDT SUN APR 19 2015

A MAJOR CHANGE IN THE OVERALL WEATHER PATTERN IS ABOUT TO BEGIN. A
STRONG AND DEEPENING LOW PRESSURE SYSTEM WILL TRACK NORTHWARD
THROUGH WESTERN LOWER MICHIGAN TONIGHT BRINGING RAIN THAT MAY BE
HEAVY AT TIMES EARLY TONIGHT. AFTER THE SYSTEM MOVES NORTH OF THE
AREA LATER TONIGHT THE RAIN WILL DIMINISH TO SHOWERS BUT IT WILL
BE BREEZY. THEN SHOWERS AND BREEZY CONDITIONS WILL CONTINUE INTO
TUESDAY. BY TUESDAY NIGHT IT WILL GET COLD ENOUGH FOR SNOW TO MIX
WITH THE RAIN. THAT WILL CONTINUE INTO THURSDAY. IT WILL BE MUCH
COOLER THROUGH THIS ENTIRE PERIOD WITH HIGHS TUESDAY THROUGH
THURSDAY IN THE 40S AND LOWS NEAR FREEZING.


&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 258 PM EDT SUN APR 19 2015

THE PRIMARY ISSUE IS THE RAIN TONIGHT...THEN WINDY AND SHOWERS
MONDAY INTO TUESDAY. THERE IS A GOOD CHANCE OF MEASURABLE SNOW
OVER NORTHERN SECTIONS TUESDAY NIGHT.

THE DEEPENING STORM SYSTEM WILL TRACK THROUGH WESTERN LOWER
MICHIGAN TONIGHT BRINGING A PERIOD OF MODERATE TO HEAVY RAIN THAT
WILL LAST AROUND 6 HOURS IN ANY ONE PLACE. IT WILL BE BREEZY AT
FIRST BUT WINDS WILL DIMINISH TOWARD MIDNIGHT AS THE SURFACE LOW
MOVES THROUGH THE AREA.

THE RAIN EVENT TONIGHT REMAINS WELL SUPPORTED BY ALL THE MODELS.
THERE IS SOME ISSUE AS TO WHERE THE HEAVIEST RAIN WILL ACTUALLY
FALL BUT ALL AREAS GET AT LEAST A THIRD OF AN INCH AND MOST AREAS
SHOULD GET MORE THAN A HALF INCH OF RAIN TONIGHT. THIS IS ALL THE
RESULT OF UPPER WAVE THAT GOES NEGATIVE TILT OVER SOUTHWEST
MICHIGAN TONIGHT. THAT CAUSES THE SURFACE LOW TO TRACK NORTHWARD
AND DEEPEN RAPIDLY. ALSO THIS RESULTS IN A STRONG LOW LEVEL JET
(60 KNOTS)... STRONG 1000 TO 850 MOISTURE CONVERGENCE AMIED AT
SOUTHWEST LOWER MICHIGAN THIS EVENING AND CONDENSATION PRESSURE
DEFICITS NEAR ZERO MB THIS EVENING. THERE IS ALSO 40 KNOT OF WIND
PERPENDICULAR TO THE ISOTROPIC SURFACES EARLY TONIGHT... AND WE
CAN ALL ADD TO THAT PRECIPITATION WATER VALUES (1.4") NEAR 2
STANDARD DEVIATIONS FROM NORMAL AND MIXING RATIOS RISING TO NEAR 8
G/KG FROM UNDER 2 G/KG THIS MORNING. THERE IS ALSO A ZONE OF
STRONG MID-LEVEL FGEN JUST AHEAD OF THE SYSTEM AS IT MOVES THROUGH
SOUTHWEST MICHIGAN TONIGHT. BOTTOM LINE... IT WOULD BE HARD TO
IMAGINE WE WILL NOT GET RAIN OVERNIGHT.

ONCE THE LOW PASSES US THE SIGNIFICANT RAINFALL WILL END. HOWEVER
THE SECONDARY COLD FRONT AND TRAILING NORTHERN STREAM WAVE WILL
BRING ANOTHER PERIOD OF SHOWERS TO THE AREA MIDDAY MONDAY INTO
EARLY EVENING. THAT BRINGS IN THE TRULY COLDER AIR.

MONDAY NIGHT WE MAY SEE A BREAK IN THE SHOWERS EARLY ON BUT THEN
THE WRAP AROUND MOISTURE MOVES IN AND WE SEE SHOWERS THAT MAY MIX
WITH AN CHANGE TO SNOW SHOWERS BY TUESDAY NIGHT. BY THE WAY THE
SPC SOUNDING CLIMATOLOGY SHOWS THE RECORD LOW 850 TEMPERATURE FOR
THE DTX SOUNDING TO BE -12C ON THE 22ND. THE ECWMF SHOWS -9.8C AT
2 PM WEDNESDAY NEAR GRR. TO SAY THE LEAST...IT WILL GET COLDER
THIS COMING WEEK!


.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

UNSEASONABLY COLD WEATHER IS ANTICIPATED WEDNESDAY AND THURSDAY WITH
DEEP CYCLONIC FLOW AND COLD AIR ADVECTION WITH THE UPPER LEVEL LOW
STILL IN PLACE OVER THE NORTHERN GREAT LAKES REGION. SCATTERED RAIN
SHOWERS WILL CONTINUE AND MAY BE MIXED AT TIMES WITH WET SNOW FLAKES
ESPECIALLY OVER RELATIVELY HIGHER ELEVATIONS OF OUR NORTHERN FCST
AREA.

TEMPERATURES SHOULD MODERATE SLIGHTLY FRIDAY THROUGH THE WEEKEND BUT
WILL STILL AVERAGE SEVERAL DEGREES BELOW NORMAL. THIS AS A SFC RIDGE
BUILDS IN AND AS THE UPPER LEVEL LOW MOVES MUCH FURTHER EAST TO THE
NEW ENGLAND REGION BY THEN. THE RIDGE WILL BRING FAIR AND SEASONABLY
COOL WEATHER FRIDAY THROUGH SUNDAY.



&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY)
ISSUED AT 1215 PM EDT SUN APR 19 2015

VFR CONDITIONS WILL CONTINUE THROUGH MID AFTERNOON. CIGS WILL LOWER
AS RAIN MOVES IN FROM SOUTH TO NORTH LATE THIS AFTERNOON AND EARLY
EVENING. PRIMARILY MVFR CONDITIONS ARE ANTICIPATED THIS EVENING AND
CONDITIONS WILL DETERIORATE FURTHER TO IFR/LIFR OVERNIGHT DUE TO
LOWERING CIGS AND SHOWERS.

WINDS WILL REMAIN STRONG/GUSTY OUT OF THE EAST THIS AFTERNOON AND
EVENING BEFORE VEERING TO THE SOUTHWEST VERY LATE TONIGHT. IFR/LIFR
CONDITIONS WILL CONTINUE THROUGH MONDAY MORNING BEFORE IMPROVING
SLOWLY TO MAINLY MVFR MONDAY AFTERNOON.


&&

.MARINE...
ISSUED AT 258 PM EDT SUN APR 19 2015

I EXTENDED THE SCA THROUGH TUESDAY AFTERNOON FOR THE ALL THE ZONES
FROM WHITEHALL SOUTH ( NORTH OF THERE WINDS WILL NOT BE AS STRONG
OVERNIGHT). AFTER THE SURFACE LOW MOVES NORTH OF MUSKEGON WINDS WILL
INCREASE TO 30 KNOTS FROM THE SOUTHWEST THEN I EXPECT 15 TO 25
KNOT WINDS MONDAY INTO TUESDAY. AS THE COLD AIR COMES IN WAVES
WILL BUILD SO WE WILL LIKELY NEED A SCA FOR THE NORTHERN TWO ZONE
GROUPS MONDAY NIGHT AND TUESDAY.

&&

.HYDROLOGY...
ISSUED AT 1114 AM EDT SUN APR 19 2015

PERIODS OF RAIN ARE EXPECTED TO DEVELOP LATE THIS AFTERNOON AND
AFFECT THE AREA OVER THE NEXT COUPLE OF DAYS. THE LIGHTER VARIETY OF
PRECIPITION MAY EXTENT INTO MIDWEEK. THOUGH WE WILL SEE A DECENT SOIL
SOAKING IT SHOULD NOT BE SUBSTANTIAL ENOUGH TO CREATE FLOODING
CONCERNS. GRADUAL BUT MINOR RISES ARE LIKELY...SUSPECTING THAT
THIS WOULD STAY WITHIN BANKS FOR MOST LOCATIONS. I WOULD NOT RULE
OUT A COUPLE OF SITES FLIRTING WITH ADVISORY STAGE AS WE GO INTO
TUESDAY...ESPECIALLY IF ANY MODERATE RAINFALL IS MORE PERSISTENT
WITH THE FIRST COUPLE OF ROUNDS OF MOISTURE. OTHERWISE...AREA
RIVERS ARE WELL BEHAVED THROUGH THE PERIOD.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR LMZ844>847.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...LAURENS
HYDROLOGY...JAM
MARINE...WDM







000
FXUS63 KMQT 191900
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
300 PM EDT SUN APR 19 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 258 PM EDT SUN APR 19 2015

TWO UPPER LEVEL WAVES WILL BE AFFECTING THE REGION TONIGHT BEFORE
MERGING TOGETHER INTO A LARGE UPPER TROUGH THAT WILL PERSIST OVER
EASTERN CANADA AND THE GREAT LAKES REGION FOR MUCH OF THE UPCOMING
WORK WEEK. THIS WILL LEAD TO A TRANSITION FROM THE ABOVE NORMAL
TEMPERATURES AND DRY CONDITIONS TO A PERIOD OF BELOW NORMAL
TEMPERATURES AND PERIODS OF RAIN/SNOW SHOWERS.

THE FIRST WAVE OF PRECIPITATION JUST BRUSHED THE WESTERN U.P.
EARLIER TODAY...ASSOCIATED WITH A SHORTWAVE AND MID LEVEL WARM AIR
ADVECTION. MUCH OF THAT PRECIPITATION HAS SHIFTED OFF TO THE NORTH
OF THE MINNESOTA ARROWHEAD...BUT LINGERING MID LEVEL MOISTURE AND
BROAD BUT WEAK WARM AIR ADVECTION HAS PRODUCED A FEW RAIN SHOWERS
OVER WESTERN/CENTRAL UPPER MICHIGAN LATE THIS MORNING AND THROUGH
THE EARLY AFTERNOON. WHILE THE 12Z KGRB SOUNDING STILL SHOWS SOME
DRY AIR BELOW THE CLOUD BASES...IT HAS ERODED SIGNIFICANTLY SINCE
THE 00Z KGRB SOUNDING AND ALLOWED SOME OF THAT RAIN TO REACH THE
GROUND. THAT DISTURBANCE PRODUCING THE SHOWERS WILL SHIFT TO THE
NORTH OVER THE NEXT COUPLE OF HOURS AND SHIFT THE FOCUS TO THE RAIN
CURRENTLY TO THE WEST AND SOUTH OF THE CWA.

WITH THE LATEST TRENDS IN THE MODELS DELAYING THE ARRIVAL OF THE
PRECIPITATION FROM THE SOUTH (ASSOCIATED WITH THE SOUTHERN WAVE AND
SURFACE LOW QUICKLY LIFTING NORTH ACROSS THE SOO MONDAY MORNING)
UNTIL LATE IN THE EVENING AND MORE DURING THE OVERNIGHT HOURS...HAVE
CONTINUED TO SHOW THAT SLOWING TREND IN THE POPS FOR THIS EVENING.
IN FACT...OTHER THAN SOME CHANCES OVER THE FAR WEST THIS
EVENING...HAVE REMOVED THE POPS OVER THE CENTRAL EAST BETWEEN THE
23Z-03Z PERIOD AND THEN RAMPED THEM UP AS THAT WAVE AND LOW ARRIVES
FROM THE SOUTH. THAT PRECIPITATION WILL THEN QUICKLY SHIFT NORTH
ACROSS THE AREA AND EXPECT MUCH OF THE CENTRAL/EASTERN U.P. TO SEE
AT LEAST 0.3 INCH OF RAIN. THERE WILL BE SOME HIGHER
AMOUNTS...LIKELY 0.5-0.6IN WHERE THE DEFORMATION ZONE OCCURS ON THE
NORTHWEST SIDE OF THE SURFACE LOW (SOMEWHERE AROUND THE CENTRAL OR
WEST-CENTRAL U.P.). FARTHER TO THE WEST...EXPECT THE ONGOING RAIN
SHOWERS STRETCHING FROM THE ARROWHEAD OF MINNESOTA THROUGH WESTERN
WISCONSIN AND INTO NORTHEAST IOWA TO SLOWLY SHIFT EAST INTO FAR
WESTERN UPPER MICHIGAN THIS EVENING...AS THE 850-700MB TROUGH SLOWLY
WORKS ITS WAY TO THE EAST. THIS PRECIPITATION WILL MERGE WITH THE
WAVE COMING UP FROM THE SOUTH AND FILL IN THE EXPECTED GAP OVER THE
KEWEENAW OVERNIGHT.

WITH THE SHORTWAVE AND SURFACE LOW QUICKLY MOVING TO THE NORTH ON
MONDAY...EXPECT THE PRECIPITATION TO DIMINISH FROM SOUTHWEST TO
NORTHEAST THROUGH THE DAY (AIDED BY THE MID LEVEL DRY SLOT THAT
SLOWLY MOVES INTO THE AREA). WHILE MUCH OF THIS PRECIP WILL OCCUR AS
RAIN...THE COLD AIR GRADUALLY MOVING INTO THE WESTERN CWA LATE
TONIGHT AND MONDAY COULD CAUSE IT TO MIXING WITH OR EVEN CHANGING
OVER TO SNOW OVER THE WEST AND POSSIBLY EVEN NORTH CENTRAL. THOUGHT
THAT THE WETBULB ZERO HAD A GOOD HANDLE ON THE WEST TO EAST
TRANSITION OF THAT MIX WITH SNOW...BUT DO HAVE A CONCERN ON THE
AMOUNT OF ICE CRYSTALS THAT WILL BE PRESENT ON MONDAY. MODELS
SHOWING THAT THE DEEPER MOISTURE REALLY BEGINS TO PULL OUT THROUGH
THE DAY AS THE MID LEVEL DRY SLOT MOVES BEHIND THE 850/700MB TROUGH.
THAT CONCERN WARRANTS KEEPING RAIN POTENTIAL IN THE FORECAST EVEN
THOUGH SOME AREAS THE WETBULB ZERO VALUES WOULD SUPPORT ALL SNOW.
ONE FINAL NOTE...THE HIGHER RESOLUTION 12Z MODELS ARE SHOWING A
SLOWER DEPARTURE TO THE PRECIP ON MONDAY...SO DID TREND SLIGHTLY
SLOWER WITH THIS FORECAST AND IT MAY NEED TO BE DELAYED FURTHER WITH
THE UPCOMING SHIFT. THAT SLOWER DEPARTURE AND INDICATIONS OF COLDER
AIR...COULD LEAD TO SOME MINOR SNOW ACCUMULATIONS ON GRASSY SURFACES
OVER THE WEST AROUND MID MORNING.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 512 AM EDT SUN APR 19 2015

COOLER WITH UNSETTLED WEATHER WILL BE THE THEME FOR MUCH OF THIS
PERIOD. THIS WILL BE AS THE SFC LOW SET UP ACROSS N LOWER MI AT 12Z
MONDAY /WITH AN INVERTED TROUGH STRETCHED UP ACROSS LAKE SUPERIOR
AND SW ONTARIO/. THE SFC LOW WILL EJECT NE OVER E ONTARIO BY
00Z...CONTINUING THE EXIT OF THE MORE STEADY RAIN/RAIN SHOWERS
DURING THE DAY MONDAY.

BY 12Z TUESDAY THE SFC LOW WILL NOT MOVE MUCH...BUT WILL EXTEND A
SFC TROUGH/SECONDARY COLD FRONT ACROSS THE W THIRD OF THE CWA. THIS
WILL BE TIMED OUT WELL WITH THE 500MB LOW NEARING THE AREA...AND
850MB TEMPS FALLING TO AROUND -7C. THE RESULT WILL BE AN ENHANCED
AREA OF PRECIP OVER THE W THIRD OF UPPER MI TUESDAY MORNING. A QUICK
BURST OF LESS THAN 2IN OF SNOW IS ANTICIPATED. WITH TEMPERATURES
BOTTOMING OUT AROUND FREEZING MONDAY NIGHT/TUESDAY MORNING...THE
BEST CHANCE OF ACCUMULATING SNOW WILL BE ON GRASSY SURFACES.

MID 30S TO MID 40S WILL BE COMMON THROUGH FRIDAY...WITH THE HIGHEST
TEMPERATURES S CENTRAL. IT WILL BE DIFFICULT TO GET RID OF AT LEAST
A MENTION OF PRECIP THROUGH THIS PERIOD AS THE SFC LOW LINGERS ALONG
THE ONTARIO/QUEBEC BORDER MONDAY EVENING THROUGH WEDNESDAY
EVENING...BEFORE SHIFTING TO MAINLY S QUEBEC THROUGH SATURDAY. THE
BROAD 500MB LOW OVERHEAD TUESDAY INTO EARLY THURSDAY WILL MOVE TO
THE LOWER GREAT LAKES AND QUEBEC THURSDAY NIGHT...BUT KEEP
ADDITIONAL DISTURBANCES ROLLING IN ON THE NW FLOW THROUGH SATURDAY.
THE OPERATIONAL GFS AND ECMWF DO NOT HAVE 850MB TEMPS WARMING ABOVE -
7C FROM TUESDAY NIGHT ON THROUGH AT LEAST FRIDAY. MUCH OF THIS
PERIOD WILL SEE SFC TEMPS OF 10 TO 15F BELOW NORMAL.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 133 PM EDT SUN APR 19 2015

VFR CONDITIONS WILL CONTINUE INTO THE EVENING HOURS...BEFORE TWO
SEPARATE FEATURES BRING WIDESPREAD RAIN AND RAPIDLY LOWERING
CEILINGS TO THE AREA LATE THIS EVENING INTO MONDAY. LINGERING LOW
LEVEL DRY AIR WILL CONTINUE TO LEAD TO MID CLOUDS AND MAYBE AN
ISOLATED SHOWERS THIS AFTERNOON. THE MAIN QUESTION MARK FOR THE
FORECAST IS THE TIMING OF THE RAIN AND IN TURN LOWER
CEILINGS/VISIBILITIES.

AT KIWD...MODELS HAVE BEEN TRENDING TOWARDS KEEPING THE HEAVIEST
PRECIPITATION OFF TO THE WEST OF THE SITE THROUGH THE EVENING.
CONFIDENCE IS LOW ON THE EASTERN EDGE OF THE PRECIPITATION...BUT
HAVE KEPT THE IDEA OF THE SHOWERS BRUSHING THE SITE BY MID EVENING
AND THEN SPREADING EAST THROUGH THE SITE TONIGHT. EXPECT THE LOW
LEVEL WINDS TO TURN OFF LAKE SUPERIOR AND WITH RAIN OVER THE COLD
WATER WOULD EXPECT LOW CLOUDS AND FOG TO AFFECT THE SITE OVERNIGHT.
THE RAIN COULD MIX WITH OR CHANGE TO SNOW TOMORROW MORNING BEFORE
ENDING TOWARDS THE END OF THE TAF PERIOD.

AT KCMX/KSAW...BOTH SITES STAY IN THE DRIER AIR LONGER BEFORE THE
PRECIPITATION QUICKLY DETERIORATES BOTH CEILINGS AND VISIBILITIES
(AFTER MIDNIGHT AND TOWARDS 09Z). WITH BOTH SITES EXPERIENCING
FAVORABLE WINDS OFF LAKE SUPERIOR LATE TONIGHT INTO MONDAY...EXPECT
LIFR CEILINGS AND SOME FOG TO OCCUR. THOSE IFR/LIFR CEILINGS WILL
REMAIN THROUGH MUCH OF MONDAY MORNING.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 258 PM EDT SUN APR 19 2015

SOUTHEASTERLY WINDS UP TO 25-30KTS ARE OCCURRING OVER NORTHEAST
LAKE SUPERIOR...WITH A FEW GUSTS NEARING GALE FORCE VALUES AT THE
HIGHER PLATFORMS (SHIP OBS AND PILM4). AS A LOW IN SOUTHERN ILLINOIS
LIFTS NORTH TONIGHT AND THROUGH THE SOO ON MONDAY MORNING...WINDS
WILL WEAKEN THIS EVENING AND THEN BACK TO THE WEST-NORTHWEST ON
MONDAY. WITH THE LOW BECOMING STATIONARY JUST TO THE SOUTHWEST OF
JAMES BAY MONDAY NIGHT THROUGH WEDNESDAY...PERSISTENT NORTHWESTERLY
WINDS OF 20-30KTS ARE EXPECTED. ALTHOUGH THE LOW WILL WEAKEN AND
MOVE EAST ACROSS QUEBEC WEDNESDAY NIGHT INTO THURSDAY...THE
NORTHWEST WINDS UP TO 25KTS WILL PERSIST AS A RIDGE MOVES INTO THE
NORTHERN PLAINS.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...SRF
LONG TERM...KF
AVIATION...SRF
MARINE...SRF



000
FXUS63 KDTX 191759
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
159 PM EDT SUN APR 19 2015


.AVIATION...

LEAD ARC OF WARM ADVECTION LIFTING THROUGH THE SOUTHERN TAF SITES
AT TAF ISSUANCE TIME WILL CONTINUE TO PUSH NORTHWARD DURING THE
AFTERNOON HOURS. PROXIMITY TO LIGHTNING STRIKES LEADING INTO THE
TAFS NECESSITATED A SHORT DURATION TEMPO FOR POSSIBLE THUNDER.
LESSENING DEPTH TO UNSTABLE POCKET UP NORTH PRECLUDE A MENTION AT
THE NORTHERN TAF SITES. QUIET CONDITIONS EXPECTED DURING THE MID
AFTERNOON HOURS BEFORE MAIN BAND OF SYNOPTIC FORCING LIFTS INTO
SOUTHEASTERN MICHIGAN AFTER 21Z. DEPTH OF MOISTURE...LOW STABILITY
AND POTENTIAL FOR MESOSCALE AUGMENTATION OF LARGER SCALE FORCING
BRINGS A POTENTIAL FOR PERIODS OF HEAVY RAINFALL THIS EVENING FOR
FAR SOUTHEASTERN MICHIGAN. CONFIDENCE IS HIGH FOR IFR CONDITIONS
TONIGHT THROUGH DAYBREAK.

FOR DTW...TEMPO GROUP EXISTS THE FIRST HOUR OF THE TAF FORECAST
FOR ARC OF SHOWERS AND POSSIBLE RUMBLE OF THUNDER ROLLING THROUGH
THE TERMINALS. QUIET MID AFTERNOON PERIOD BEFORE CONDITIONS
DETERIORATE RAPIDLY AFTER 21Z. THE POTENTIAL EXISTS FOR A PERIOD
OF HEAVY RAINFALL THIS EVENING...BEFORE IFR CONDITIONS SETTLE IN
THROUGH DAYBREAK.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CIGS FALLING BELOW 5KFT LATE THIS AFTERNOON.

* LOW CONFIDENCE IN THUNDERSTORMS.

&&

.PREV DISCUSSION...ISSUED 1043 AM EDT SUN APR 19 2015

UPDATE...

THE PREVIOUS DISCUSSION ISSUED WITH THE MORNING FORECAST PACKAGE
OUTLINES THE TODAY AND TONIGHT PERIODS VERY WELL AND REMAINS AN
OUTSTANDING REFERENCE.

THE MAIN OBJECTIVES OF THE RECENT UPDATE WAS TO REFINE TIMING OF
PRECIPITATION CHANCES THIS AFTERNOON AND EVENING AND TO INCLUDE A
CHANCE OF THUNDER. THERE ARE A FEW MAIN POINTS TO DRIVE HOME.

THE FIRST IS CONCERNING THE CHANCE OF SHOWERS AND A THUNDERSTORM
THIS AFTERNOON. MODEL DATA SUPPORTS CARRYING THE CURRENT ACTIVITY
SOUTH OF CLEVELAND NORTHWESTWARD. THE CONVECTION IS OCCURING ALONG
AN ENHANCED GRADIENT OF MOISTURE/WARM FRONTAL ARC THAT HAS ORIGINS
FROM THE APPLACHIAN CHAIN. THIS ACTIVITY IS EXPECTED TO PUSH
ACROSS LAKE ERIE AND ARRIVE OVER SOUTHEASTERN MICHIGAN BETWEEN
15-18Z. MODEL DATA DOES SUPPORT SOME POTENTIAL FOR INCREASING
AREAL COVERAGE WHEN IT ARRIVES. DID INTRODUCE A THUNDER MENTION
GIVEN THE TREND OF KCLE REFLECTIVIES AND NLDN LIGHTNING REPORTS.
SOUNDINGS SUGGEST AS MUCH AS A FEW HUNDRED J/KG OF MUCAPE WITH A
POCKET OF STEEP LAPSE RATES BETWEEN 800-700MB. EXPECT THIS
CONDITIONAL ACTIVITY TO PUSH STEADILY NORTHWARD THROUGHOUT THE
AFTERNOON.

THE SECOND POINT OF EMPHASIS IS WITH THE TIMING OF THE MAIN BAND
OF PRECIPITATION NOW LIFTING INTO SOUTHERN SECTIONS OF SOUTHERN
INDIANA AND SOUTHERN OHIO. OVERWHELMING MODEL SUPPORT EXISTS ALONG
WITH AGREEMENT FROM RADAR LINEAR EXTRAPOLATION TIME OF ARRIVAL IN
BRINGING THIS AREA OF SOAKING RAINS ACROSS THE SOUTHERN CWA BORDER
RIGHT AT 21Z. PUSHED TIMING OF CATEGORICAL POPS BACK A FEW
HOURS. A SHORTER DURATION OF HEAVY RAINFALL OUTLINED IN RECENT
DISCUSSIONS CERTAINLY REMAINS A POSSIBILITY FOR THIS EVENING.

PREV DISCUSSION...ISSUED 355 AM EDT SUN APR 19 2015

SHORT TERM...TODAY AND TONIGHT

LARGE EXPANSE OF QUIET WEATHER STRETCHING FROM MISSOURI INTO
KENTUCKY AT 07Z THIS MORNING AS THE FORCING ASSOCIATED WITH THE
STRONG LOW OVER THE WESTERN HIGH PLAINS HAS YET TO ARRIVE. A PARTIAL
COVERAGE OF SHOWERS IS NOTED INVOF MEMPHIS/PADUCAH WITHIN THE
RESERVOIR OF HIGH MOISTURE CONTENT RESIDING OVER THE TENNESSEE AND
LOWER OHIO RIVER VALLEYS. THE SHORTWAVE DIGGING INTO THE NORTHERN
PLAINS WILL CAUSE THE STRONG CLOSED LOW OVER KS TO OPEN UP AND
TRANSLATE EAST OVER THE NEXT 24 HOURS. THE ARRIVAL OF DEEP LAYER
SOUTH/SOUTHEAST FLOW EAST OF THE MISSISSIPPI RIVER BY 18Z WILL
ADVECT THIS SLUG OF MOISTURE NORTHWARD. AT THE SAME TIME,
SUPERPOSITION OF INCREASINGLY FAVORABLE UPPER ATMOSPHERE DIVERGENCE
AND ISENTROPIC ASCENT WILL FORCE RAINFALL TO BLOSSOM OVER KY/IL/IN
THROUGHOUT THE MORNING.

SUPPORTED IN PART BY A COMPLEX OF SHORTWAVE ENERGY EMANATING FROM
CONVECTION OVER THE DEEP SOUTH, THIS ACTIVITY WILL LIFT TOWARD
LOWER MICHIGAN DURING THE DAY. INITIAL ARRIVAL OF MID-LEVEL MOISTURE
COINCIDENT WITH A NARROW BAND OF 290-295K ASCENT MAY SUPPORT A FEW
SHOWERS DURING THE LATE MORNING-MID AFTERNOON, BUT LACK OF
APPRECIABLE DEPTH/DURATION SUGGESTS MAINTAINING A CONSERVATIVE
APPROACH TO THE FORECAST THROUGH THIS PERIOD. AS SUCH, HELD MOST
PLACES AT 30-40 POP WITH MINIMAL QPF THROUGH AT LEAST 21Z. STIFF
EASTERLY FLOW WILL PUT A LID ON HIGH TEMPERATURES, BUT STILL EXPECT
MOST PLACES NOT NEAR LAKE SHORES TO APPROACH OR EXCEED 60 DEGREES,
ROUGHLY IN LINE WITH THE 00Z MAV GUIDANCE, AS PREDOMINANTLY DRY
CONDITIONS DOMINATE THROUGH LATE AFTERNOON.

PRIMARY CORRIDOR OF 305-310K ISENTROPIC ASCENT WILL LIFT FROM SOUTH
TO NORTH THROUGH THE FORECAST AREA 21Z-06Z THIS EVENING BENEATH
STRONGLY DIVERGENT FLOW ALOFT. LOW-LEVEL JET FORCING COULD BE
CONSIDERABLE DURING AT LEAST A PORTION OF THIS TIME FRAME AS A 60-
70KT LLJ IMPINGES ON THE EASTERN CWA. STRONG MOISTURE TRANSPORT
CENTERED WITHIN A DEEP 10KFT WARM CLOUD LAYER WILL LEND ITSELF TO
HIGHLY EFFICIENT HYDROMETEOR PRODUCTION AND SEVERAL HOURS OF
MODERATE RAIN WITH EMBEDDED HEAVY SHOWERS. FAVORED GUIDANCE
INDICATES A QPF MAXIMUM ALONG/EAST OF THE GLACIAL RIDGE WITH A SOLID
0.6" TO 0.8" AREAL AVERAGE ACROSS THE URBAN CORRIDORS OF METRO
DETROIT. URBAN AND SMALL STREAM FLOODING WILL BE POSSIBLE, LARGELY
DEPENDENT ON NATURE OF LLJ EVOLUTION DURING THE LOWER IMPACT
TIME PERIOD OF 02-07Z FOR DETROIT AND SURROUNDING AREAS.

RAIN WILL DIMINISH IN COVERAGE AS THE WING OF STRONG ISENTROPIC
ASCENT AND A SIZEABLE PERCENTAGE OF MID-LEVEL MOISTURE LIFTS NORTH.
HOWEVER, INCREASINGLY CYCLONIC FLOW WILL BE SPREADING INTO LOWER
MICHIGAN AT THIS TIME AND THE ABUNDANCE OF REMNANT LOW-LEVEL
MOISTURE WILL BE ACCOMPANIED BY STEEPENING LAPSE RATES AS THE
THERMAL RIDGE LIFTS NORTHEAST. AS A RESULT, EXPECT A HEALTHY
COVERAGE OF SHOWERS TO CONTINUE INTO THE PREDAWN HOURS MONDAY
MORNING. THE STRONG GRADIENT AND STEEP LAPSE RATE ENVIRONMENT SHOULD
ALSO CONTRIBUTE TO A PERIOD OF 25 TO POSSIBLY 30 KT WIND GUSTS
BEFORE THE STRONG WIND FIELD OVER SE MICHIGAN DIMINISHES EARLY
MONDAY.

LONG TERM...MONDAY THROUGH SATURDAY

AFTER A FAIRLY PLEASANT WEEK OR TWO IN SE MI THE LONG TERM TAKES A
TURN BACK TO COOL AND DREARY WITH SEVERAL OPPORTUNITIES FOR RAIN
SHOWERS...AND POSSIBLY A FEW SNOWFLAKES.

BY MONDAY THE REGION WILL BE BE ENGULFED BY A LARGE AREA OF SFC LOW
PRESSURE RESULTING FROM COMPLEX INTERACTION OF THE NORTHERN AND
SOUTHERN STREAMS OF THE JET IN ADDITION TO THE REMNANTS OF A CUTOFF
LOW THAT DRIFTED ACROSS THE CONUS OVER THE LAST FEW DAYS. THE
MID/UPPER LEVEL TROUGH WILL STILL BE OFF TO OUR WEST BY MONDAY
MORNING WITH THE FIRST STRONG SHORTWAVE LIFTING THROUGH THE NORTHERN
GREAT LAKES INTO ONTARIO. MODELS CONTINUE TO ADVERTISE ONE MORE
SOUTHERN STREAM SHORTWAVE LIFTING NNE ALONG A COLD FRONT PUSHING
EAST THROUGH SOUTHERN MI. THERE MAY BE A BIT OF A LULL IN THE PRECIP
EARLY MONDAY AS WE LOOK TO FALL IN A REGION OF SUBSIDENCE BETWEEN
THE TWO SHORTWAVES. THERE REMAINS LOWER CONFIDENCE IN TIMING OF ANY
OF THESE FEATURES AS MODELS HAVE BEEN CONTINUALLY SLOWING DOWN DUE
TO NOT HANDLING THE DEEPENING OF THE SYSTEM EFFECTIVELY YET. SO WILL
START OFF THE DAY WITH CHANCE POPS AND INCREASE LATER IN THE
AFTERNOON WHEN THE WAVE LOOKS TO LIFT THROUGH. THE TIMING IS
PRESENTING ADDITIONAL PROBLEMS REGARDING INSTABILITY AHEAD OF THE
COLD FRONT. CURRENTLY MODELS ARE SHOWING THE WARM SECTOR OF THE WAVE
JUST SKIRTING TO THE SOUTH OF SOUTHERN MI...YET THEY KEEP SOME HINT
OF INSTABILITY ALONG THE FRONT IN SE MI. IF THE SYSTEM CAN SLOW DOWN
A BIT MORE ALLOWING THE CENTER OF THE WAVE TO LIFT WEST OF THE
DETROIT METRO...WE MAY GET A LITTLE BOOST IN INSTABILITY FROM THE
WARM SECTOR CLIPPING THE AREA. MORAL OF THE STORY IS THAT WILL LEAVE
THE MENTION OF THUNDER IN THE FORECAST MONDAY AFTERNOON.
EXPECTATIONS ARE FOR RAIN SHOWERS ALONG THE FRONT WITH A FEW RUMBLES
OF THUNDER POSSIBLE.

THE REAL PUSH OF COLD AIR COMES WITH A COLD FRONT POSITIONED ALONG
THE MID LEVEL TROUGH AXIS PIVOTING THROUGH EARLY MONDAY NIGHT. THE
NORTHERN STREAM OF THE JET WILL BE ALIGNED NORTH TO SOUTH WHICH WILL
FUNNEL COLD AIR INTO THE REGION. WITH THE UPPER LOW STALLING OVER
THE AREA INTO THE WEEKEND...THIS CAA PATTERN WILL REMAIN IN PLACE
THROUGH THE END OF THE WEEK. 850MB TEMPS WILL FALL BELOW 0C MONDAY
NIGHT...DROPPING TO NEAR -10C BY THURSDAY NIGHT...BEFORE RIDGING
LOOKS TO DISPLACE THE LOW EASTWARD OVER THE WEEKEND. THE AIRMASS
WILL BE MUCH DRIER WITH PWATS AROUND 0.3 INCHES WHICH WILL RESULT IN
ONLY SOME CHANCE OR SLIGHT CHANCE POPS AS ADDITIONAL LOBES OF
VORTICITY ROTATE DOWN AROUND THE LOW THROUGH THE REGION THROUGH MID
WEEK. OTHERWISE LOOK FOR HIGH TEMPS TO STRUGGLE TO HIT 50 AT TIMES
WITH LOWS FALLING TO AROUND FREEZING.

MARINE...

HIGH PRESSURE CENTERED OVER THE ONTARIO/QUEBEC BORDER HAS SET UP
EASTERLY FLOW ACROSS THE REGION. THIS FLOW WILL INCREASE TODAY AS
LOW PRESSURE DEEPENS AND LIFTS TOWARD THE GREAT LAKES FROM THE
SOUTH. SMALL CRAFT ADVISORIES HAVE BEEN ISSUED FOR ALL NEARSHORE
ZONES AS GUSTY WINDS BUILD WAVE HEIGHTS ALONG THE SHORELINES NOW
INTO EARLY MONDAY. THOUGH SOME GUSTS MAY APPROACH GALE FORCE...THE
MARINE LAYER LOOKS TO BE FAIRLY STABLE WHICH WILL LIMIT THIS
POTENTIAL. AFTER STALLING A BIT OVER THE REGION TONIGHT...THE LOW
WILL LIFT NORTHWARD TO NEAR JAMES BAY BY MONDAY NIGHT. THIS WILL
ALLOW WINDS TO GRADUALLY RELAX THROUGH THE DAY MONDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LHZ441>443.

     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 2 PM EDT MONDAY FOR
     LHZ421-422.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 8 AM EDT MONDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LEZ444.

&&

$$

AVIATION.....CB
UPDATE.......CB
SHORT TERM...JVC
LONG TERM....DRK
MARINE.......DRK


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).



000
FXUS63 KDTX 191759
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
159 PM EDT SUN APR 19 2015


.AVIATION...

LEAD ARC OF WARM ADVECTION LIFTING THROUGH THE SOUTHERN TAF SITES
AT TAF ISSUANCE TIME WILL CONTINUE TO PUSH NORTHWARD DURING THE
AFTERNOON HOURS. PROXIMITY TO LIGHTNING STRIKES LEADING INTO THE
TAFS NECESSITATED A SHORT DURATION TEMPO FOR POSSIBLE THUNDER.
LESSENING DEPTH TO UNSTABLE POCKET UP NORTH PRECLUDE A MENTION AT
THE NORTHERN TAF SITES. QUIET CONDITIONS EXPECTED DURING THE MID
AFTERNOON HOURS BEFORE MAIN BAND OF SYNOPTIC FORCING LIFTS INTO
SOUTHEASTERN MICHIGAN AFTER 21Z. DEPTH OF MOISTURE...LOW STABILITY
AND POTENTIAL FOR MESOSCALE AUGMENTATION OF LARGER SCALE FORCING
BRINGS A POTENTIAL FOR PERIODS OF HEAVY RAINFALL THIS EVENING FOR
FAR SOUTHEASTERN MICHIGAN. CONFIDENCE IS HIGH FOR IFR CONDITIONS
TONIGHT THROUGH DAYBREAK.

FOR DTW...TEMPO GROUP EXISTS THE FIRST HOUR OF THE TAF FORECAST
FOR ARC OF SHOWERS AND POSSIBLE RUMBLE OF THUNDER ROLLING THROUGH
THE TERMINALS. QUIET MID AFTERNOON PERIOD BEFORE CONDITIONS
DETERIORATE RAPIDLY AFTER 21Z. THE POTENTIAL EXISTS FOR A PERIOD
OF HEAVY RAINFALL THIS EVENING...BEFORE IFR CONDITIONS SETTLE IN
THROUGH DAYBREAK.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CIGS FALLING BELOW 5KFT LATE THIS AFTERNOON.

* LOW CONFIDENCE IN THUNDERSTORMS.

&&

.PREV DISCUSSION...ISSUED 1043 AM EDT SUN APR 19 2015

UPDATE...

THE PREVIOUS DISCUSSION ISSUED WITH THE MORNING FORECAST PACKAGE
OUTLINES THE TODAY AND TONIGHT PERIODS VERY WELL AND REMAINS AN
OUTSTANDING REFERENCE.

THE MAIN OBJECTIVES OF THE RECENT UPDATE WAS TO REFINE TIMING OF
PRECIPITATION CHANCES THIS AFTERNOON AND EVENING AND TO INCLUDE A
CHANCE OF THUNDER. THERE ARE A FEW MAIN POINTS TO DRIVE HOME.

THE FIRST IS CONCERNING THE CHANCE OF SHOWERS AND A THUNDERSTORM
THIS AFTERNOON. MODEL DATA SUPPORTS CARRYING THE CURRENT ACTIVITY
SOUTH OF CLEVELAND NORTHWESTWARD. THE CONVECTION IS OCCURING ALONG
AN ENHANCED GRADIENT OF MOISTURE/WARM FRONTAL ARC THAT HAS ORIGINS
FROM THE APPLACHIAN CHAIN. THIS ACTIVITY IS EXPECTED TO PUSH
ACROSS LAKE ERIE AND ARRIVE OVER SOUTHEASTERN MICHIGAN BETWEEN
15-18Z. MODEL DATA DOES SUPPORT SOME POTENTIAL FOR INCREASING
AREAL COVERAGE WHEN IT ARRIVES. DID INTRODUCE A THUNDER MENTION
GIVEN THE TREND OF KCLE REFLECTIVIES AND NLDN LIGHTNING REPORTS.
SOUNDINGS SUGGEST AS MUCH AS A FEW HUNDRED J/KG OF MUCAPE WITH A
POCKET OF STEEP LAPSE RATES BETWEEN 800-700MB. EXPECT THIS
CONDITIONAL ACTIVITY TO PUSH STEADILY NORTHWARD THROUGHOUT THE
AFTERNOON.

THE SECOND POINT OF EMPHASIS IS WITH THE TIMING OF THE MAIN BAND
OF PRECIPITATION NOW LIFTING INTO SOUTHERN SECTIONS OF SOUTHERN
INDIANA AND SOUTHERN OHIO. OVERWHELMING MODEL SUPPORT EXISTS ALONG
WITH AGREEMENT FROM RADAR LINEAR EXTRAPOLATION TIME OF ARRIVAL IN
BRINGING THIS AREA OF SOAKING RAINS ACROSS THE SOUTHERN CWA BORDER
RIGHT AT 21Z. PUSHED TIMING OF CATEGORICAL POPS BACK A FEW
HOURS. A SHORTER DURATION OF HEAVY RAINFALL OUTLINED IN RECENT
DISCUSSIONS CERTAINLY REMAINS A POSSIBILITY FOR THIS EVENING.

PREV DISCUSSION...ISSUED 355 AM EDT SUN APR 19 2015

SHORT TERM...TODAY AND TONIGHT

LARGE EXPANSE OF QUIET WEATHER STRETCHING FROM MISSOURI INTO
KENTUCKY AT 07Z THIS MORNING AS THE FORCING ASSOCIATED WITH THE
STRONG LOW OVER THE WESTERN HIGH PLAINS HAS YET TO ARRIVE. A PARTIAL
COVERAGE OF SHOWERS IS NOTED INVOF MEMPHIS/PADUCAH WITHIN THE
RESERVOIR OF HIGH MOISTURE CONTENT RESIDING OVER THE TENNESSEE AND
LOWER OHIO RIVER VALLEYS. THE SHORTWAVE DIGGING INTO THE NORTHERN
PLAINS WILL CAUSE THE STRONG CLOSED LOW OVER KS TO OPEN UP AND
TRANSLATE EAST OVER THE NEXT 24 HOURS. THE ARRIVAL OF DEEP LAYER
SOUTH/SOUTHEAST FLOW EAST OF THE MISSISSIPPI RIVER BY 18Z WILL
ADVECT THIS SLUG OF MOISTURE NORTHWARD. AT THE SAME TIME,
SUPERPOSITION OF INCREASINGLY FAVORABLE UPPER ATMOSPHERE DIVERGENCE
AND ISENTROPIC ASCENT WILL FORCE RAINFALL TO BLOSSOM OVER KY/IL/IN
THROUGHOUT THE MORNING.

SUPPORTED IN PART BY A COMPLEX OF SHORTWAVE ENERGY EMANATING FROM
CONVECTION OVER THE DEEP SOUTH, THIS ACTIVITY WILL LIFT TOWARD
LOWER MICHIGAN DURING THE DAY. INITIAL ARRIVAL OF MID-LEVEL MOISTURE
COINCIDENT WITH A NARROW BAND OF 290-295K ASCENT MAY SUPPORT A FEW
SHOWERS DURING THE LATE MORNING-MID AFTERNOON, BUT LACK OF
APPRECIABLE DEPTH/DURATION SUGGESTS MAINTAINING A CONSERVATIVE
APPROACH TO THE FORECAST THROUGH THIS PERIOD. AS SUCH, HELD MOST
PLACES AT 30-40 POP WITH MINIMAL QPF THROUGH AT LEAST 21Z. STIFF
EASTERLY FLOW WILL PUT A LID ON HIGH TEMPERATURES, BUT STILL EXPECT
MOST PLACES NOT NEAR LAKE SHORES TO APPROACH OR EXCEED 60 DEGREES,
ROUGHLY IN LINE WITH THE 00Z MAV GUIDANCE, AS PREDOMINANTLY DRY
CONDITIONS DOMINATE THROUGH LATE AFTERNOON.

PRIMARY CORRIDOR OF 305-310K ISENTROPIC ASCENT WILL LIFT FROM SOUTH
TO NORTH THROUGH THE FORECAST AREA 21Z-06Z THIS EVENING BENEATH
STRONGLY DIVERGENT FLOW ALOFT. LOW-LEVEL JET FORCING COULD BE
CONSIDERABLE DURING AT LEAST A PORTION OF THIS TIME FRAME AS A 60-
70KT LLJ IMPINGES ON THE EASTERN CWA. STRONG MOISTURE TRANSPORT
CENTERED WITHIN A DEEP 10KFT WARM CLOUD LAYER WILL LEND ITSELF TO
HIGHLY EFFICIENT HYDROMETEOR PRODUCTION AND SEVERAL HOURS OF
MODERATE RAIN WITH EMBEDDED HEAVY SHOWERS. FAVORED GUIDANCE
INDICATES A QPF MAXIMUM ALONG/EAST OF THE GLACIAL RIDGE WITH A SOLID
0.6" TO 0.8" AREAL AVERAGE ACROSS THE URBAN CORRIDORS OF METRO
DETROIT. URBAN AND SMALL STREAM FLOODING WILL BE POSSIBLE, LARGELY
DEPENDENT ON NATURE OF LLJ EVOLUTION DURING THE LOWER IMPACT
TIME PERIOD OF 02-07Z FOR DETROIT AND SURROUNDING AREAS.

RAIN WILL DIMINISH IN COVERAGE AS THE WING OF STRONG ISENTROPIC
ASCENT AND A SIZEABLE PERCENTAGE OF MID-LEVEL MOISTURE LIFTS NORTH.
HOWEVER, INCREASINGLY CYCLONIC FLOW WILL BE SPREADING INTO LOWER
MICHIGAN AT THIS TIME AND THE ABUNDANCE OF REMNANT LOW-LEVEL
MOISTURE WILL BE ACCOMPANIED BY STEEPENING LAPSE RATES AS THE
THERMAL RIDGE LIFTS NORTHEAST. AS A RESULT, EXPECT A HEALTHY
COVERAGE OF SHOWERS TO CONTINUE INTO THE PREDAWN HOURS MONDAY
MORNING. THE STRONG GRADIENT AND STEEP LAPSE RATE ENVIRONMENT SHOULD
ALSO CONTRIBUTE TO A PERIOD OF 25 TO POSSIBLY 30 KT WIND GUSTS
BEFORE THE STRONG WIND FIELD OVER SE MICHIGAN DIMINISHES EARLY
MONDAY.

LONG TERM...MONDAY THROUGH SATURDAY

AFTER A FAIRLY PLEASANT WEEK OR TWO IN SE MI THE LONG TERM TAKES A
TURN BACK TO COOL AND DREARY WITH SEVERAL OPPORTUNITIES FOR RAIN
SHOWERS...AND POSSIBLY A FEW SNOWFLAKES.

BY MONDAY THE REGION WILL BE BE ENGULFED BY A LARGE AREA OF SFC LOW
PRESSURE RESULTING FROM COMPLEX INTERACTION OF THE NORTHERN AND
SOUTHERN STREAMS OF THE JET IN ADDITION TO THE REMNANTS OF A CUTOFF
LOW THAT DRIFTED ACROSS THE CONUS OVER THE LAST FEW DAYS. THE
MID/UPPER LEVEL TROUGH WILL STILL BE OFF TO OUR WEST BY MONDAY
MORNING WITH THE FIRST STRONG SHORTWAVE LIFTING THROUGH THE NORTHERN
GREAT LAKES INTO ONTARIO. MODELS CONTINUE TO ADVERTISE ONE MORE
SOUTHERN STREAM SHORTWAVE LIFTING NNE ALONG A COLD FRONT PUSHING
EAST THROUGH SOUTHERN MI. THERE MAY BE A BIT OF A LULL IN THE PRECIP
EARLY MONDAY AS WE LOOK TO FALL IN A REGION OF SUBSIDENCE BETWEEN
THE TWO SHORTWAVES. THERE REMAINS LOWER CONFIDENCE IN TIMING OF ANY
OF THESE FEATURES AS MODELS HAVE BEEN CONTINUALLY SLOWING DOWN DUE
TO NOT HANDLING THE DEEPENING OF THE SYSTEM EFFECTIVELY YET. SO WILL
START OFF THE DAY WITH CHANCE POPS AND INCREASE LATER IN THE
AFTERNOON WHEN THE WAVE LOOKS TO LIFT THROUGH. THE TIMING IS
PRESENTING ADDITIONAL PROBLEMS REGARDING INSTABILITY AHEAD OF THE
COLD FRONT. CURRENTLY MODELS ARE SHOWING THE WARM SECTOR OF THE WAVE
JUST SKIRTING TO THE SOUTH OF SOUTHERN MI...YET THEY KEEP SOME HINT
OF INSTABILITY ALONG THE FRONT IN SE MI. IF THE SYSTEM CAN SLOW DOWN
A BIT MORE ALLOWING THE CENTER OF THE WAVE TO LIFT WEST OF THE
DETROIT METRO...WE MAY GET A LITTLE BOOST IN INSTABILITY FROM THE
WARM SECTOR CLIPPING THE AREA. MORAL OF THE STORY IS THAT WILL LEAVE
THE MENTION OF THUNDER IN THE FORECAST MONDAY AFTERNOON.
EXPECTATIONS ARE FOR RAIN SHOWERS ALONG THE FRONT WITH A FEW RUMBLES
OF THUNDER POSSIBLE.

THE REAL PUSH OF COLD AIR COMES WITH A COLD FRONT POSITIONED ALONG
THE MID LEVEL TROUGH AXIS PIVOTING THROUGH EARLY MONDAY NIGHT. THE
NORTHERN STREAM OF THE JET WILL BE ALIGNED NORTH TO SOUTH WHICH WILL
FUNNEL COLD AIR INTO THE REGION. WITH THE UPPER LOW STALLING OVER
THE AREA INTO THE WEEKEND...THIS CAA PATTERN WILL REMAIN IN PLACE
THROUGH THE END OF THE WEEK. 850MB TEMPS WILL FALL BELOW 0C MONDAY
NIGHT...DROPPING TO NEAR -10C BY THURSDAY NIGHT...BEFORE RIDGING
LOOKS TO DISPLACE THE LOW EASTWARD OVER THE WEEKEND. THE AIRMASS
WILL BE MUCH DRIER WITH PWATS AROUND 0.3 INCHES WHICH WILL RESULT IN
ONLY SOME CHANCE OR SLIGHT CHANCE POPS AS ADDITIONAL LOBES OF
VORTICITY ROTATE DOWN AROUND THE LOW THROUGH THE REGION THROUGH MID
WEEK. OTHERWISE LOOK FOR HIGH TEMPS TO STRUGGLE TO HIT 50 AT TIMES
WITH LOWS FALLING TO AROUND FREEZING.

MARINE...

HIGH PRESSURE CENTERED OVER THE ONTARIO/QUEBEC BORDER HAS SET UP
EASTERLY FLOW ACROSS THE REGION. THIS FLOW WILL INCREASE TODAY AS
LOW PRESSURE DEEPENS AND LIFTS TOWARD THE GREAT LAKES FROM THE
SOUTH. SMALL CRAFT ADVISORIES HAVE BEEN ISSUED FOR ALL NEARSHORE
ZONES AS GUSTY WINDS BUILD WAVE HEIGHTS ALONG THE SHORELINES NOW
INTO EARLY MONDAY. THOUGH SOME GUSTS MAY APPROACH GALE FORCE...THE
MARINE LAYER LOOKS TO BE FAIRLY STABLE WHICH WILL LIMIT THIS
POTENTIAL. AFTER STALLING A BIT OVER THE REGION TONIGHT...THE LOW
WILL LIFT NORTHWARD TO NEAR JAMES BAY BY MONDAY NIGHT. THIS WILL
ALLOW WINDS TO GRADUALLY RELAX THROUGH THE DAY MONDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LHZ441>443.

     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 2 PM EDT MONDAY FOR
     LHZ421-422.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 8 AM EDT MONDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LEZ444.

&&

$$

AVIATION.....CB
UPDATE.......CB
SHORT TERM...JVC
LONG TERM....DRK
MARINE.......DRK


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).




000
FXUS63 KDTX 191759
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
159 PM EDT SUN APR 19 2015


.AVIATION...

LEAD ARC OF WARM ADVECTION LIFTING THROUGH THE SOUTHERN TAF SITES
AT TAF ISSUANCE TIME WILL CONTINUE TO PUSH NORTHWARD DURING THE
AFTERNOON HOURS. PROXIMITY TO LIGHTNING STRIKES LEADING INTO THE
TAFS NECESSITATED A SHORT DURATION TEMPO FOR POSSIBLE THUNDER.
LESSENING DEPTH TO UNSTABLE POCKET UP NORTH PRECLUDE A MENTION AT
THE NORTHERN TAF SITES. QUIET CONDITIONS EXPECTED DURING THE MID
AFTERNOON HOURS BEFORE MAIN BAND OF SYNOPTIC FORCING LIFTS INTO
SOUTHEASTERN MICHIGAN AFTER 21Z. DEPTH OF MOISTURE...LOW STABILITY
AND POTENTIAL FOR MESOSCALE AUGMENTATION OF LARGER SCALE FORCING
BRINGS A POTENTIAL FOR PERIODS OF HEAVY RAINFALL THIS EVENING FOR
FAR SOUTHEASTERN MICHIGAN. CONFIDENCE IS HIGH FOR IFR CONDITIONS
TONIGHT THROUGH DAYBREAK.

FOR DTW...TEMPO GROUP EXISTS THE FIRST HOUR OF THE TAF FORECAST
FOR ARC OF SHOWERS AND POSSIBLE RUMBLE OF THUNDER ROLLING THROUGH
THE TERMINALS. QUIET MID AFTERNOON PERIOD BEFORE CONDITIONS
DETERIORATE RAPIDLY AFTER 21Z. THE POTENTIAL EXISTS FOR A PERIOD
OF HEAVY RAINFALL THIS EVENING...BEFORE IFR CONDITIONS SETTLE IN
THROUGH DAYBREAK.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CIGS FALLING BELOW 5KFT LATE THIS AFTERNOON.

* LOW CONFIDENCE IN THUNDERSTORMS.

&&

.PREV DISCUSSION...ISSUED 1043 AM EDT SUN APR 19 2015

UPDATE...

THE PREVIOUS DISCUSSION ISSUED WITH THE MORNING FORECAST PACKAGE
OUTLINES THE TODAY AND TONIGHT PERIODS VERY WELL AND REMAINS AN
OUTSTANDING REFERENCE.

THE MAIN OBJECTIVES OF THE RECENT UPDATE WAS TO REFINE TIMING OF
PRECIPITATION CHANCES THIS AFTERNOON AND EVENING AND TO INCLUDE A
CHANCE OF THUNDER. THERE ARE A FEW MAIN POINTS TO DRIVE HOME.

THE FIRST IS CONCERNING THE CHANCE OF SHOWERS AND A THUNDERSTORM
THIS AFTERNOON. MODEL DATA SUPPORTS CARRYING THE CURRENT ACTIVITY
SOUTH OF CLEVELAND NORTHWESTWARD. THE CONVECTION IS OCCURING ALONG
AN ENHANCED GRADIENT OF MOISTURE/WARM FRONTAL ARC THAT HAS ORIGINS
FROM THE APPLACHIAN CHAIN. THIS ACTIVITY IS EXPECTED TO PUSH
ACROSS LAKE ERIE AND ARRIVE OVER SOUTHEASTERN MICHIGAN BETWEEN
15-18Z. MODEL DATA DOES SUPPORT SOME POTENTIAL FOR INCREASING
AREAL COVERAGE WHEN IT ARRIVES. DID INTRODUCE A THUNDER MENTION
GIVEN THE TREND OF KCLE REFLECTIVIES AND NLDN LIGHTNING REPORTS.
SOUNDINGS SUGGEST AS MUCH AS A FEW HUNDRED J/KG OF MUCAPE WITH A
POCKET OF STEEP LAPSE RATES BETWEEN 800-700MB. EXPECT THIS
CONDITIONAL ACTIVITY TO PUSH STEADILY NORTHWARD THROUGHOUT THE
AFTERNOON.

THE SECOND POINT OF EMPHASIS IS WITH THE TIMING OF THE MAIN BAND
OF PRECIPITATION NOW LIFTING INTO SOUTHERN SECTIONS OF SOUTHERN
INDIANA AND SOUTHERN OHIO. OVERWHELMING MODEL SUPPORT EXISTS ALONG
WITH AGREEMENT FROM RADAR LINEAR EXTRAPOLATION TIME OF ARRIVAL IN
BRINGING THIS AREA OF SOAKING RAINS ACROSS THE SOUTHERN CWA BORDER
RIGHT AT 21Z. PUSHED TIMING OF CATEGORICAL POPS BACK A FEW
HOURS. A SHORTER DURATION OF HEAVY RAINFALL OUTLINED IN RECENT
DISCUSSIONS CERTAINLY REMAINS A POSSIBILITY FOR THIS EVENING.

PREV DISCUSSION...ISSUED 355 AM EDT SUN APR 19 2015

SHORT TERM...TODAY AND TONIGHT

LARGE EXPANSE OF QUIET WEATHER STRETCHING FROM MISSOURI INTO
KENTUCKY AT 07Z THIS MORNING AS THE FORCING ASSOCIATED WITH THE
STRONG LOW OVER THE WESTERN HIGH PLAINS HAS YET TO ARRIVE. A PARTIAL
COVERAGE OF SHOWERS IS NOTED INVOF MEMPHIS/PADUCAH WITHIN THE
RESERVOIR OF HIGH MOISTURE CONTENT RESIDING OVER THE TENNESSEE AND
LOWER OHIO RIVER VALLEYS. THE SHORTWAVE DIGGING INTO THE NORTHERN
PLAINS WILL CAUSE THE STRONG CLOSED LOW OVER KS TO OPEN UP AND
TRANSLATE EAST OVER THE NEXT 24 HOURS. THE ARRIVAL OF DEEP LAYER
SOUTH/SOUTHEAST FLOW EAST OF THE MISSISSIPPI RIVER BY 18Z WILL
ADVECT THIS SLUG OF MOISTURE NORTHWARD. AT THE SAME TIME,
SUPERPOSITION OF INCREASINGLY FAVORABLE UPPER ATMOSPHERE DIVERGENCE
AND ISENTROPIC ASCENT WILL FORCE RAINFALL TO BLOSSOM OVER KY/IL/IN
THROUGHOUT THE MORNING.

SUPPORTED IN PART BY A COMPLEX OF SHORTWAVE ENERGY EMANATING FROM
CONVECTION OVER THE DEEP SOUTH, THIS ACTIVITY WILL LIFT TOWARD
LOWER MICHIGAN DURING THE DAY. INITIAL ARRIVAL OF MID-LEVEL MOISTURE
COINCIDENT WITH A NARROW BAND OF 290-295K ASCENT MAY SUPPORT A FEW
SHOWERS DURING THE LATE MORNING-MID AFTERNOON, BUT LACK OF
APPRECIABLE DEPTH/DURATION SUGGESTS MAINTAINING A CONSERVATIVE
APPROACH TO THE FORECAST THROUGH THIS PERIOD. AS SUCH, HELD MOST
PLACES AT 30-40 POP WITH MINIMAL QPF THROUGH AT LEAST 21Z. STIFF
EASTERLY FLOW WILL PUT A LID ON HIGH TEMPERATURES, BUT STILL EXPECT
MOST PLACES NOT NEAR LAKE SHORES TO APPROACH OR EXCEED 60 DEGREES,
ROUGHLY IN LINE WITH THE 00Z MAV GUIDANCE, AS PREDOMINANTLY DRY
CONDITIONS DOMINATE THROUGH LATE AFTERNOON.

PRIMARY CORRIDOR OF 305-310K ISENTROPIC ASCENT WILL LIFT FROM SOUTH
TO NORTH THROUGH THE FORECAST AREA 21Z-06Z THIS EVENING BENEATH
STRONGLY DIVERGENT FLOW ALOFT. LOW-LEVEL JET FORCING COULD BE
CONSIDERABLE DURING AT LEAST A PORTION OF THIS TIME FRAME AS A 60-
70KT LLJ IMPINGES ON THE EASTERN CWA. STRONG MOISTURE TRANSPORT
CENTERED WITHIN A DEEP 10KFT WARM CLOUD LAYER WILL LEND ITSELF TO
HIGHLY EFFICIENT HYDROMETEOR PRODUCTION AND SEVERAL HOURS OF
MODERATE RAIN WITH EMBEDDED HEAVY SHOWERS. FAVORED GUIDANCE
INDICATES A QPF MAXIMUM ALONG/EAST OF THE GLACIAL RIDGE WITH A SOLID
0.6" TO 0.8" AREAL AVERAGE ACROSS THE URBAN CORRIDORS OF METRO
DETROIT. URBAN AND SMALL STREAM FLOODING WILL BE POSSIBLE, LARGELY
DEPENDENT ON NATURE OF LLJ EVOLUTION DURING THE LOWER IMPACT
TIME PERIOD OF 02-07Z FOR DETROIT AND SURROUNDING AREAS.

RAIN WILL DIMINISH IN COVERAGE AS THE WING OF STRONG ISENTROPIC
ASCENT AND A SIZEABLE PERCENTAGE OF MID-LEVEL MOISTURE LIFTS NORTH.
HOWEVER, INCREASINGLY CYCLONIC FLOW WILL BE SPREADING INTO LOWER
MICHIGAN AT THIS TIME AND THE ABUNDANCE OF REMNANT LOW-LEVEL
MOISTURE WILL BE ACCOMPANIED BY STEEPENING LAPSE RATES AS THE
THERMAL RIDGE LIFTS NORTHEAST. AS A RESULT, EXPECT A HEALTHY
COVERAGE OF SHOWERS TO CONTINUE INTO THE PREDAWN HOURS MONDAY
MORNING. THE STRONG GRADIENT AND STEEP LAPSE RATE ENVIRONMENT SHOULD
ALSO CONTRIBUTE TO A PERIOD OF 25 TO POSSIBLY 30 KT WIND GUSTS
BEFORE THE STRONG WIND FIELD OVER SE MICHIGAN DIMINISHES EARLY
MONDAY.

LONG TERM...MONDAY THROUGH SATURDAY

AFTER A FAIRLY PLEASANT WEEK OR TWO IN SE MI THE LONG TERM TAKES A
TURN BACK TO COOL AND DREARY WITH SEVERAL OPPORTUNITIES FOR RAIN
SHOWERS...AND POSSIBLY A FEW SNOWFLAKES.

BY MONDAY THE REGION WILL BE BE ENGULFED BY A LARGE AREA OF SFC LOW
PRESSURE RESULTING FROM COMPLEX INTERACTION OF THE NORTHERN AND
SOUTHERN STREAMS OF THE JET IN ADDITION TO THE REMNANTS OF A CUTOFF
LOW THAT DRIFTED ACROSS THE CONUS OVER THE LAST FEW DAYS. THE
MID/UPPER LEVEL TROUGH WILL STILL BE OFF TO OUR WEST BY MONDAY
MORNING WITH THE FIRST STRONG SHORTWAVE LIFTING THROUGH THE NORTHERN
GREAT LAKES INTO ONTARIO. MODELS CONTINUE TO ADVERTISE ONE MORE
SOUTHERN STREAM SHORTWAVE LIFTING NNE ALONG A COLD FRONT PUSHING
EAST THROUGH SOUTHERN MI. THERE MAY BE A BIT OF A LULL IN THE PRECIP
EARLY MONDAY AS WE LOOK TO FALL IN A REGION OF SUBSIDENCE BETWEEN
THE TWO SHORTWAVES. THERE REMAINS LOWER CONFIDENCE IN TIMING OF ANY
OF THESE FEATURES AS MODELS HAVE BEEN CONTINUALLY SLOWING DOWN DUE
TO NOT HANDLING THE DEEPENING OF THE SYSTEM EFFECTIVELY YET. SO WILL
START OFF THE DAY WITH CHANCE POPS AND INCREASE LATER IN THE
AFTERNOON WHEN THE WAVE LOOKS TO LIFT THROUGH. THE TIMING IS
PRESENTING ADDITIONAL PROBLEMS REGARDING INSTABILITY AHEAD OF THE
COLD FRONT. CURRENTLY MODELS ARE SHOWING THE WARM SECTOR OF THE WAVE
JUST SKIRTING TO THE SOUTH OF SOUTHERN MI...YET THEY KEEP SOME HINT
OF INSTABILITY ALONG THE FRONT IN SE MI. IF THE SYSTEM CAN SLOW DOWN
A BIT MORE ALLOWING THE CENTER OF THE WAVE TO LIFT WEST OF THE
DETROIT METRO...WE MAY GET A LITTLE BOOST IN INSTABILITY FROM THE
WARM SECTOR CLIPPING THE AREA. MORAL OF THE STORY IS THAT WILL LEAVE
THE MENTION OF THUNDER IN THE FORECAST MONDAY AFTERNOON.
EXPECTATIONS ARE FOR RAIN SHOWERS ALONG THE FRONT WITH A FEW RUMBLES
OF THUNDER POSSIBLE.

THE REAL PUSH OF COLD AIR COMES WITH A COLD FRONT POSITIONED ALONG
THE MID LEVEL TROUGH AXIS PIVOTING THROUGH EARLY MONDAY NIGHT. THE
NORTHERN STREAM OF THE JET WILL BE ALIGNED NORTH TO SOUTH WHICH WILL
FUNNEL COLD AIR INTO THE REGION. WITH THE UPPER LOW STALLING OVER
THE AREA INTO THE WEEKEND...THIS CAA PATTERN WILL REMAIN IN PLACE
THROUGH THE END OF THE WEEK. 850MB TEMPS WILL FALL BELOW 0C MONDAY
NIGHT...DROPPING TO NEAR -10C BY THURSDAY NIGHT...BEFORE RIDGING
LOOKS TO DISPLACE THE LOW EASTWARD OVER THE WEEKEND. THE AIRMASS
WILL BE MUCH DRIER WITH PWATS AROUND 0.3 INCHES WHICH WILL RESULT IN
ONLY SOME CHANCE OR SLIGHT CHANCE POPS AS ADDITIONAL LOBES OF
VORTICITY ROTATE DOWN AROUND THE LOW THROUGH THE REGION THROUGH MID
WEEK. OTHERWISE LOOK FOR HIGH TEMPS TO STRUGGLE TO HIT 50 AT TIMES
WITH LOWS FALLING TO AROUND FREEZING.

MARINE...

HIGH PRESSURE CENTERED OVER THE ONTARIO/QUEBEC BORDER HAS SET UP
EASTERLY FLOW ACROSS THE REGION. THIS FLOW WILL INCREASE TODAY AS
LOW PRESSURE DEEPENS AND LIFTS TOWARD THE GREAT LAKES FROM THE
SOUTH. SMALL CRAFT ADVISORIES HAVE BEEN ISSUED FOR ALL NEARSHORE
ZONES AS GUSTY WINDS BUILD WAVE HEIGHTS ALONG THE SHORELINES NOW
INTO EARLY MONDAY. THOUGH SOME GUSTS MAY APPROACH GALE FORCE...THE
MARINE LAYER LOOKS TO BE FAIRLY STABLE WHICH WILL LIMIT THIS
POTENTIAL. AFTER STALLING A BIT OVER THE REGION TONIGHT...THE LOW
WILL LIFT NORTHWARD TO NEAR JAMES BAY BY MONDAY NIGHT. THIS WILL
ALLOW WINDS TO GRADUALLY RELAX THROUGH THE DAY MONDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR LHZ441>443.

     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 2 PM EDT MONDAY FOR
     LHZ421-422.

LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 8 AM EDT MONDAY FOR LCZ460.

MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR LEZ444.

&&

$$

AVIATION.....CB
UPDATE.......CB
SHORT TERM...JVC
LONG TERM....DRK
MARINE.......DRK


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).



000
FXUS63 KAPX 191748
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
148 PM EDT SUN APR 19 2015

.UPDATE...
ISSUED AT 1249 PM EDT SUN APR 19 2015

LOOKS LIKE THE MOISTURE IS SLOW INTO MOVING INTO THE REGION. SO
HAVE SLOWED DOWN THE PROGRESSION OF THE RAIN CONSIDERABLY. THE
CHANCE OF RAIN AREA IS NOW JUST GETTING TO M-55 BY 21Z INSTEAD OF
UP M-32. THIS IS BASED BOTH BY THE CURRENT OBS AND THE LATEST
GFS/NAM WITH THE RAP13 EVEN SLOWER. ALL OF THE MODELS AGREE THAT
THE RAIN SHOULD BE INTO E UPPER BY 06Z. SO WILL HOLD ONTO THAT
IDEA FOR NOW.

UPDATE ISSUED AT 952 AM EDT SUN APR 19 2015

HUDSON BAY HIGH IS SLOWLY MOVING EAST AND ALLOWING THE DEVELOPING
LOW PRESSURE SYSTEM IN THE CENTRAL PLAINS TO SLIDE INTO THE UPPER
GREAT LAKES. THE MAIN CONCERN FOR THE AFTERNOON, IS THE TIMING OF
THE RAIN START OR IF THE DRY AIR WILL CONTINUE A LITTLE LONGER.
BESIDES SLOWING THE RAIN START, THE DRY AIR COULD ALSO CAUSE AN
EXTENDED FIRE WEATHER CONCERN. HOWEVER, WITH THE CLOUDS
INCREASING, AND THE MOISTURE EXPECTED TO INCREASE WILL CONTINUE
WITH THE GOING FORECAST. WILL PROBABLY UPDATE THIS DISCUSSION
AROUND 1PM TO TALK ABOUT TIMING THEN AS WELL.

&&

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 237 AM EDT SUN APR 19 2015

STRONG HIGH PRESSURE CENTERED NE OF MICHIGAN REMAINS FIRMLY IN
CONTROL OF OUR WEATHER EARLY THIS MORNING...WITH MAINLY CLEAR SKIES
STILL OVERHEAD. HIGH CLOUD SHIELD ALONG THE NRN FRINGE OF INCREASING
MOISTURE HAS REACHED SRN LWR MICHIGAN...WELL NORTH OF DEVELOPING LOW
PRESSURE OVER THE MID MISSISSIPPI VALLEY. THIS LOW WILL GRADUALLY
DEEPEN AS IT LIFTS NE INTO LWR MICHIGAN TONIGHT...REACHING SAGINAW
BAY AND NE LWR MICHIGAN BY 12Z MONDAY. WIDESPREAD RAIN WILL DEVELOP
FROM SOUTH TO NORTH BEGINNING LATE AFTERNOON/EARLY EVENING...WITH
WIDESPREAD RAIN THEN CONTINUING FOR THE REMAINDER OF THE NIGHT AS
DEEP MOISTURE AND STRONG 700-500 MB LEVEL OMEGA LIFT INTO THE AREA
ALONG AND AHEAD OF THE SURFACE LOW CENTER.

IN THE MEANTIME...THE ONLY REAL CONCERN FOR TODAY IS THE POTENTIAL
FOR ONE MORE DAY OF ELEVATED FIRE DANGER GIVEN RECENT PERSISTENT DRY
CONDITIONS PRIOR TO GREEN UP. MINIMUM RH VALUES WILL LIKELY FALL
INTO THE MID TO UPPER 20S ACROSS INLAND AREAS OF NW LWR MICHIGAN BY
EARLY AFTERNOON BEFORE LOW LEVEL MOISTURE/RH BEGINS TO INCREASE IN
ADVANCE OF PRECIP DEVELOPMENT. TEMPS WILL BE SLIGHTLY COOLER
TODAY...WITH HIGHS MAINLY IN THE MID 50S TO LOWER 60S. HOWEVER...
E/SE SURFACE WINDS WILL QUICKLY STRENGTHEN TODAY UPON COMMENCEMENT
OF DAYTIME MIXING...WITH GUSTS OF 15 TO 25 MPH EXPECTED. GIVEN THE
GUSTY WINDS AND LOWER RH VALUES (ESPECIALLY EARLY AFTERNOON)...WILL
AGAIN MENTION THE ELEVATED FIRE DANGER IN THE HWO AND FWF THRU MID
AFTERNOON BEFORE INCREASING RH VALUES AND DEVELOPING PRECIP BRINGS A
CLOSE TO OUR DRY SPELL.

&&

.SHORT TERM...(MONDAY THROUGH TUESDAY NIGHT)
ISSUED AT 237 AM EDT SUN APR 19 2015

HIGH IMPACT WEATHER POTENTIAL: NOTHING SIGNIFICANT

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: NO SURPRISES WITH LATEST AND
GREATEST GUIDANCE TRENDS...WITH ROCK STEADY INTRA/INTER MODEL AND
ENSEMBLE SOLUTIONS SHOWING THE DEVELOPMENT...AND SUBSEQUENT SLOW
MOVEMENT...OF DEEP CLOSED LOW PRESSURE ACROSS THE FAR NORTHERN LAKES
THIS UPCOMING WEEK. ATTENDANT COLD CORE ANOMALIES/STEEP MID LEVEL
LAPSE RATES AND ENERGY PINWHEELING AROUND PARENT SYSTEM WILL BRING
BELOW NORMAL TEMPERATURES AND PERIODS OF SHOWERS...WHICH AT TIMES
WILL NOT BE OF THE LIQUID VARIETY. TRENDS LOOK DRIER BY LATE IN THE
WEEK INTO THE START OF NEXT WEEKEND...ALTHOUGH WITH STILL BELOW
NORMAL TEMPERATURES.

PRIMARY FORECAST CONCERNS/CHALLENGES: NO CHANGE FROM EARLIER...WITH
TEMPERATURE TRENDS AND PRECIP TIMING/COVERAGE/AND TYPE CONCERNS
DOMINATING MUCH OF THE FORECAST.

DETAILS: AMPLIFICATION PROCESSES KICKS INTO OVERDRIVE TO START THE
WEEK AS STRONG NORTHERN STREAM ENERGY DIVES INTO THE UPPER
MISSISSIPPI VALLEY. SUNDAY NIGHT`S WIDESPREAD RAIN PRODUCING SOUTHERN
STREAM WAVE LOOKS TO EXIT NORTHEAST OF OUR AREA MONDAY
MORNING...QUICKLY FOLLOWED BY REMNANTS OF CURRENT WESTERN KANSAS
SHORTWAVE AS IT BECOMES ABSORBED INTO STRONGER NORTHERN STREAM
TROUGH. STILL SOME QUESTION WITH LOCATION OF BETTER FORCING WITH
THIS LATTER FEATURE...BUT EITHER WAY...LOOKS LIKE SHOWERS A PRETTY
SAFE BET.

MONDAY NIGHT - TUESDAY NIGHT WEATHER DOMINATED BY THAT DEEPENING AND
INCREASINGLY CLOSED OFF UPPER/MID LEVEL LOW AS IT SLOWLY MEANDERS
ACROSS THE FAR NORTHERN LAKES. HINTS MUCH OF THE AREA ACTUALLY MIGHT
CATCH A BREAK MONDAY NIGHT...WAITING FOR DEEPER "WRAP AROUND"
MOISTURE TO WORK BACK INTO THE REGION TUESDAY AND TUESDAY NIGHT. H8
TEMPERATURES FALLING SEVERAL DEGREES BELOW ZERO AND STEEP LOW LEVEL
LAPSE RATES ARGUES ANY SURFACE BASED MELTING LAYER TUESDAY COULD BE
QUICKLY OVERCOME...SUPPORTING PRIMARILY SNOW SHOWERS WHEN
PRECIPITATION FALLS HEAVIEST. THIS SHOULD ESPECIALLY BE TRUE FAR
NORTH AND ACROSS INTERIOR HIGHER LOCALES. MELTING LAYER IS LOST FOR
MOST TUESDAY NIGHT...SUGGESTING MAINLY SNOW. PRECIP LOOKS
SHOWERY...DRIVEN IN LARGE PART FROM DIURNAL TRENDS AND PASSING MID
LEVEL SUPPORT. COULD SEE SOME ENHANCED FOCUS INTO NORTHWEST LOWER
WITH PERSISTENT MOIST UPSLOPE FLOW WITHIN WEST TO NORTHWEST WINDS.
SUPPOSE SOME LIGHT ACCUMULATIONS ARE POSSIBLE IN THIS AREA...BUT
DEFINITELY NOT ENOUGH TO WARRANT ANY MENTION IN OUR HAZARDOUS
WEATHER PRODUCTS.

&&

.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 237 AM EDT SUN APR 19 2015

REALLY NOT A WHOLE LOT OF
CHANGE EXPECTED TO START THIS PERIOD...WITH DIURNAL ENHANCEMENT AND
PASSING WAVES SUPPORTING MORE RAIN/SNOW SHOWERS RIGHT THROUGH
THURSDAY. REALLY HATE TO SAY THIS...BUT EVEN HINTS OVERHEAD AIR MAY
BE JUST COLD ENOUGH TO SUPPORT SOME MARGINAL LAKE ENHANCEMENT...
ESPECIALLY NOW WITH MOSTLY ICE-FREE CONDITIONS. SHOULDN`T BE TOO BIG
A DEAL IF THIS DOES OCCUR...AND PER LATE SPRING USUAL..."MOST" WOULD
OCCUR WEDNESDAY NIGHT WHEN DIURNAL DISRUPTION IS MINIMIZED.

WHILE DETAILS ARE ELUDING WITH RESPECT TO JUST HOW FAST SYSTEM
PUSHES OFF TO THE EAST...CANNOT FIND A COMPELLING REASON TO DEVIATE
FROM INHERITED DRY FORECAST THURSDAY NIGHT RIGHT THROUGH SATURDAY.
DEFINITELY PLAUSIBLE TROUGHING WILL REMAIN CLOSE ENOUGH TO ALLOW
ADDITIONAL WAVES/ATTENDANT SHOWERS TO PASS OVERHEAD. STILL HAVE
PLENTY OF TIME TO WATCH HOW THIS ALL UNFOLDS. EITHER WAY...COOL
CONDITIONS WILL NOT BE SO EASILY SCOURED OUT...WITH BELOW NORMAL
TEMPERATURES CONTINUING INTO THE START OF THE WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 142 PM EDT SUN APR 19 2015

MOISTURE HAS BEEN SLOW TO MOVE INTO THE REGION THIS AFTERNOON, AND
THUS, HAVE BEEN SLOWING DOWN THE TIMING OF THE RAIN. BEST GUESS AT
THIS POINT IN THE AFTERNOON, IS THAT IT SHOWS UP AROUND 23Z AT
MBL/TVC AREA, AND ABOUT 00Z AT APN/PLN. AFTER THAT THE VSBY LOOKS
TO FALL INTO THE MVFR CATEGORY, BUT THE CIGS BY 12Z/MON FALL TO
IFR AS THE LOW MOVES OVER US AND BRINGS MORE MOISTURE OVER THE
REGION.

&&

.MARINE...
ISSUED AT 237 AM EDT SUN APR 19 2015

LOW PRESSURE WILL LIFT NE INTO MICHIGAN TONIGHT...PRODUCING
WIDESPREAD RAIN ACROSS OUR ENTIRE NEARSHORE AREA. STRENGTHENING
EAST/SOUTHEAST WINDS AHEAD OF THAT SYSTEM TODAY AND TONIGHT WILL
LEAD TO SCA CONDITIONS FOR MUCH OF OUR NEARSHORE AREA...WITH WIND
GUSTS OF 15 TO 25 KTS EXPECTED. THE EXCEPTION WILL BE THE LAKE
MICHIGAN SHORELINE FROM MANISTEE TO THE BRIDGE...WHICH SHOULD FALL
JUST SHORT OF SCA CRITERIA.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LSZ321-322.

&&

$$

UPDATE...JSL
NEAR TERM...MLR
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...JSL
MARINE...MLR



000
FXUS63 KAPX 191748
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
148 PM EDT SUN APR 19 2015

.UPDATE...
ISSUED AT 1249 PM EDT SUN APR 19 2015

LOOKS LIKE THE MOISTURE IS SLOW INTO MOVING INTO THE REGION. SO
HAVE SLOWED DOWN THE PROGRESSION OF THE RAIN CONSIDERABLY. THE
CHANCE OF RAIN AREA IS NOW JUST GETTING TO M-55 BY 21Z INSTEAD OF
UP M-32. THIS IS BASED BOTH BY THE CURRENT OBS AND THE LATEST
GFS/NAM WITH THE RAP13 EVEN SLOWER. ALL OF THE MODELS AGREE THAT
THE RAIN SHOULD BE INTO E UPPER BY 06Z. SO WILL HOLD ONTO THAT
IDEA FOR NOW.

UPDATE ISSUED AT 952 AM EDT SUN APR 19 2015

HUDSON BAY HIGH IS SLOWLY MOVING EAST AND ALLOWING THE DEVELOPING
LOW PRESSURE SYSTEM IN THE CENTRAL PLAINS TO SLIDE INTO THE UPPER
GREAT LAKES. THE MAIN CONCERN FOR THE AFTERNOON, IS THE TIMING OF
THE RAIN START OR IF THE DRY AIR WILL CONTINUE A LITTLE LONGER.
BESIDES SLOWING THE RAIN START, THE DRY AIR COULD ALSO CAUSE AN
EXTENDED FIRE WEATHER CONCERN. HOWEVER, WITH THE CLOUDS
INCREASING, AND THE MOISTURE EXPECTED TO INCREASE WILL CONTINUE
WITH THE GOING FORECAST. WILL PROBABLY UPDATE THIS DISCUSSION
AROUND 1PM TO TALK ABOUT TIMING THEN AS WELL.

&&

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 237 AM EDT SUN APR 19 2015

STRONG HIGH PRESSURE CENTERED NE OF MICHIGAN REMAINS FIRMLY IN
CONTROL OF OUR WEATHER EARLY THIS MORNING...WITH MAINLY CLEAR SKIES
STILL OVERHEAD. HIGH CLOUD SHIELD ALONG THE NRN FRINGE OF INCREASING
MOISTURE HAS REACHED SRN LWR MICHIGAN...WELL NORTH OF DEVELOPING LOW
PRESSURE OVER THE MID MISSISSIPPI VALLEY. THIS LOW WILL GRADUALLY
DEEPEN AS IT LIFTS NE INTO LWR MICHIGAN TONIGHT...REACHING SAGINAW
BAY AND NE LWR MICHIGAN BY 12Z MONDAY. WIDESPREAD RAIN WILL DEVELOP
FROM SOUTH TO NORTH BEGINNING LATE AFTERNOON/EARLY EVENING...WITH
WIDESPREAD RAIN THEN CONTINUING FOR THE REMAINDER OF THE NIGHT AS
DEEP MOISTURE AND STRONG 700-500 MB LEVEL OMEGA LIFT INTO THE AREA
ALONG AND AHEAD OF THE SURFACE LOW CENTER.

IN THE MEANTIME...THE ONLY REAL CONCERN FOR TODAY IS THE POTENTIAL
FOR ONE MORE DAY OF ELEVATED FIRE DANGER GIVEN RECENT PERSISTENT DRY
CONDITIONS PRIOR TO GREEN UP. MINIMUM RH VALUES WILL LIKELY FALL
INTO THE MID TO UPPER 20S ACROSS INLAND AREAS OF NW LWR MICHIGAN BY
EARLY AFTERNOON BEFORE LOW LEVEL MOISTURE/RH BEGINS TO INCREASE IN
ADVANCE OF PRECIP DEVELOPMENT. TEMPS WILL BE SLIGHTLY COOLER
TODAY...WITH HIGHS MAINLY IN THE MID 50S TO LOWER 60S. HOWEVER...
E/SE SURFACE WINDS WILL QUICKLY STRENGTHEN TODAY UPON COMMENCEMENT
OF DAYTIME MIXING...WITH GUSTS OF 15 TO 25 MPH EXPECTED. GIVEN THE
GUSTY WINDS AND LOWER RH VALUES (ESPECIALLY EARLY AFTERNOON)...WILL
AGAIN MENTION THE ELEVATED FIRE DANGER IN THE HWO AND FWF THRU MID
AFTERNOON BEFORE INCREASING RH VALUES AND DEVELOPING PRECIP BRINGS A
CLOSE TO OUR DRY SPELL.

&&

.SHORT TERM...(MONDAY THROUGH TUESDAY NIGHT)
ISSUED AT 237 AM EDT SUN APR 19 2015

HIGH IMPACT WEATHER POTENTIAL: NOTHING SIGNIFICANT

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: NO SURPRISES WITH LATEST AND
GREATEST GUIDANCE TRENDS...WITH ROCK STEADY INTRA/INTER MODEL AND
ENSEMBLE SOLUTIONS SHOWING THE DEVELOPMENT...AND SUBSEQUENT SLOW
MOVEMENT...OF DEEP CLOSED LOW PRESSURE ACROSS THE FAR NORTHERN LAKES
THIS UPCOMING WEEK. ATTENDANT COLD CORE ANOMALIES/STEEP MID LEVEL
LAPSE RATES AND ENERGY PINWHEELING AROUND PARENT SYSTEM WILL BRING
BELOW NORMAL TEMPERATURES AND PERIODS OF SHOWERS...WHICH AT TIMES
WILL NOT BE OF THE LIQUID VARIETY. TRENDS LOOK DRIER BY LATE IN THE
WEEK INTO THE START OF NEXT WEEKEND...ALTHOUGH WITH STILL BELOW
NORMAL TEMPERATURES.

PRIMARY FORECAST CONCERNS/CHALLENGES: NO CHANGE FROM EARLIER...WITH
TEMPERATURE TRENDS AND PRECIP TIMING/COVERAGE/AND TYPE CONCERNS
DOMINATING MUCH OF THE FORECAST.

DETAILS: AMPLIFICATION PROCESSES KICKS INTO OVERDRIVE TO START THE
WEEK AS STRONG NORTHERN STREAM ENERGY DIVES INTO THE UPPER
MISSISSIPPI VALLEY. SUNDAY NIGHT`S WIDESPREAD RAIN PRODUCING SOUTHERN
STREAM WAVE LOOKS TO EXIT NORTHEAST OF OUR AREA MONDAY
MORNING...QUICKLY FOLLOWED BY REMNANTS OF CURRENT WESTERN KANSAS
SHORTWAVE AS IT BECOMES ABSORBED INTO STRONGER NORTHERN STREAM
TROUGH. STILL SOME QUESTION WITH LOCATION OF BETTER FORCING WITH
THIS LATTER FEATURE...BUT EITHER WAY...LOOKS LIKE SHOWERS A PRETTY
SAFE BET.

MONDAY NIGHT - TUESDAY NIGHT WEATHER DOMINATED BY THAT DEEPENING AND
INCREASINGLY CLOSED OFF UPPER/MID LEVEL LOW AS IT SLOWLY MEANDERS
ACROSS THE FAR NORTHERN LAKES. HINTS MUCH OF THE AREA ACTUALLY MIGHT
CATCH A BREAK MONDAY NIGHT...WAITING FOR DEEPER "WRAP AROUND"
MOISTURE TO WORK BACK INTO THE REGION TUESDAY AND TUESDAY NIGHT. H8
TEMPERATURES FALLING SEVERAL DEGREES BELOW ZERO AND STEEP LOW LEVEL
LAPSE RATES ARGUES ANY SURFACE BASED MELTING LAYER TUESDAY COULD BE
QUICKLY OVERCOME...SUPPORTING PRIMARILY SNOW SHOWERS WHEN
PRECIPITATION FALLS HEAVIEST. THIS SHOULD ESPECIALLY BE TRUE FAR
NORTH AND ACROSS INTERIOR HIGHER LOCALES. MELTING LAYER IS LOST FOR
MOST TUESDAY NIGHT...SUGGESTING MAINLY SNOW. PRECIP LOOKS
SHOWERY...DRIVEN IN LARGE PART FROM DIURNAL TRENDS AND PASSING MID
LEVEL SUPPORT. COULD SEE SOME ENHANCED FOCUS INTO NORTHWEST LOWER
WITH PERSISTENT MOIST UPSLOPE FLOW WITHIN WEST TO NORTHWEST WINDS.
SUPPOSE SOME LIGHT ACCUMULATIONS ARE POSSIBLE IN THIS AREA...BUT
DEFINITELY NOT ENOUGH TO WARRANT ANY MENTION IN OUR HAZARDOUS
WEATHER PRODUCTS.

&&

.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 237 AM EDT SUN APR 19 2015

REALLY NOT A WHOLE LOT OF
CHANGE EXPECTED TO START THIS PERIOD...WITH DIURNAL ENHANCEMENT AND
PASSING WAVES SUPPORTING MORE RAIN/SNOW SHOWERS RIGHT THROUGH
THURSDAY. REALLY HATE TO SAY THIS...BUT EVEN HINTS OVERHEAD AIR MAY
BE JUST COLD ENOUGH TO SUPPORT SOME MARGINAL LAKE ENHANCEMENT...
ESPECIALLY NOW WITH MOSTLY ICE-FREE CONDITIONS. SHOULDN`T BE TOO BIG
A DEAL IF THIS DOES OCCUR...AND PER LATE SPRING USUAL..."MOST" WOULD
OCCUR WEDNESDAY NIGHT WHEN DIURNAL DISRUPTION IS MINIMIZED.

WHILE DETAILS ARE ELUDING WITH RESPECT TO JUST HOW FAST SYSTEM
PUSHES OFF TO THE EAST...CANNOT FIND A COMPELLING REASON TO DEVIATE
FROM INHERITED DRY FORECAST THURSDAY NIGHT RIGHT THROUGH SATURDAY.
DEFINITELY PLAUSIBLE TROUGHING WILL REMAIN CLOSE ENOUGH TO ALLOW
ADDITIONAL WAVES/ATTENDANT SHOWERS TO PASS OVERHEAD. STILL HAVE
PLENTY OF TIME TO WATCH HOW THIS ALL UNFOLDS. EITHER WAY...COOL
CONDITIONS WILL NOT BE SO EASILY SCOURED OUT...WITH BELOW NORMAL
TEMPERATURES CONTINUING INTO THE START OF THE WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 142 PM EDT SUN APR 19 2015

MOISTURE HAS BEEN SLOW TO MOVE INTO THE REGION THIS AFTERNOON, AND
THUS, HAVE BEEN SLOWING DOWN THE TIMING OF THE RAIN. BEST GUESS AT
THIS POINT IN THE AFTERNOON, IS THAT IT SHOWS UP AROUND 23Z AT
MBL/TVC AREA, AND ABOUT 00Z AT APN/PLN. AFTER THAT THE VSBY LOOKS
TO FALL INTO THE MVFR CATEGORY, BUT THE CIGS BY 12Z/MON FALL TO
IFR AS THE LOW MOVES OVER US AND BRINGS MORE MOISTURE OVER THE
REGION.

&&

.MARINE...
ISSUED AT 237 AM EDT SUN APR 19 2015

LOW PRESSURE WILL LIFT NE INTO MICHIGAN TONIGHT...PRODUCING
WIDESPREAD RAIN ACROSS OUR ENTIRE NEARSHORE AREA. STRENGTHENING
EAST/SOUTHEAST WINDS AHEAD OF THAT SYSTEM TODAY AND TONIGHT WILL
LEAD TO SCA CONDITIONS FOR MUCH OF OUR NEARSHORE AREA...WITH WIND
GUSTS OF 15 TO 25 KTS EXPECTED. THE EXCEPTION WILL BE THE LAKE
MICHIGAN SHORELINE FROM MANISTEE TO THE BRIDGE...WHICH SHOULD FALL
JUST SHORT OF SCA CRITERIA.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LSZ321-322.

&&

$$

UPDATE...JSL
NEAR TERM...MLR
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...JSL
MARINE...MLR



000
FXUS63 KAPX 191748
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
148 PM EDT SUN APR 19 2015

.UPDATE...
ISSUED AT 1249 PM EDT SUN APR 19 2015

LOOKS LIKE THE MOISTURE IS SLOW INTO MOVING INTO THE REGION. SO
HAVE SLOWED DOWN THE PROGRESSION OF THE RAIN CONSIDERABLY. THE
CHANCE OF RAIN AREA IS NOW JUST GETTING TO M-55 BY 21Z INSTEAD OF
UP M-32. THIS IS BASED BOTH BY THE CURRENT OBS AND THE LATEST
GFS/NAM WITH THE RAP13 EVEN SLOWER. ALL OF THE MODELS AGREE THAT
THE RAIN SHOULD BE INTO E UPPER BY 06Z. SO WILL HOLD ONTO THAT
IDEA FOR NOW.

UPDATE ISSUED AT 952 AM EDT SUN APR 19 2015

HUDSON BAY HIGH IS SLOWLY MOVING EAST AND ALLOWING THE DEVELOPING
LOW PRESSURE SYSTEM IN THE CENTRAL PLAINS TO SLIDE INTO THE UPPER
GREAT LAKES. THE MAIN CONCERN FOR THE AFTERNOON, IS THE TIMING OF
THE RAIN START OR IF THE DRY AIR WILL CONTINUE A LITTLE LONGER.
BESIDES SLOWING THE RAIN START, THE DRY AIR COULD ALSO CAUSE AN
EXTENDED FIRE WEATHER CONCERN. HOWEVER, WITH THE CLOUDS
INCREASING, AND THE MOISTURE EXPECTED TO INCREASE WILL CONTINUE
WITH THE GOING FORECAST. WILL PROBABLY UPDATE THIS DISCUSSION
AROUND 1PM TO TALK ABOUT TIMING THEN AS WELL.

&&

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 237 AM EDT SUN APR 19 2015

STRONG HIGH PRESSURE CENTERED NE OF MICHIGAN REMAINS FIRMLY IN
CONTROL OF OUR WEATHER EARLY THIS MORNING...WITH MAINLY CLEAR SKIES
STILL OVERHEAD. HIGH CLOUD SHIELD ALONG THE NRN FRINGE OF INCREASING
MOISTURE HAS REACHED SRN LWR MICHIGAN...WELL NORTH OF DEVELOPING LOW
PRESSURE OVER THE MID MISSISSIPPI VALLEY. THIS LOW WILL GRADUALLY
DEEPEN AS IT LIFTS NE INTO LWR MICHIGAN TONIGHT...REACHING SAGINAW
BAY AND NE LWR MICHIGAN BY 12Z MONDAY. WIDESPREAD RAIN WILL DEVELOP
FROM SOUTH TO NORTH BEGINNING LATE AFTERNOON/EARLY EVENING...WITH
WIDESPREAD RAIN THEN CONTINUING FOR THE REMAINDER OF THE NIGHT AS
DEEP MOISTURE AND STRONG 700-500 MB LEVEL OMEGA LIFT INTO THE AREA
ALONG AND AHEAD OF THE SURFACE LOW CENTER.

IN THE MEANTIME...THE ONLY REAL CONCERN FOR TODAY IS THE POTENTIAL
FOR ONE MORE DAY OF ELEVATED FIRE DANGER GIVEN RECENT PERSISTENT DRY
CONDITIONS PRIOR TO GREEN UP. MINIMUM RH VALUES WILL LIKELY FALL
INTO THE MID TO UPPER 20S ACROSS INLAND AREAS OF NW LWR MICHIGAN BY
EARLY AFTERNOON BEFORE LOW LEVEL MOISTURE/RH BEGINS TO INCREASE IN
ADVANCE OF PRECIP DEVELOPMENT. TEMPS WILL BE SLIGHTLY COOLER
TODAY...WITH HIGHS MAINLY IN THE MID 50S TO LOWER 60S. HOWEVER...
E/SE SURFACE WINDS WILL QUICKLY STRENGTHEN TODAY UPON COMMENCEMENT
OF DAYTIME MIXING...WITH GUSTS OF 15 TO 25 MPH EXPECTED. GIVEN THE
GUSTY WINDS AND LOWER RH VALUES (ESPECIALLY EARLY AFTERNOON)...WILL
AGAIN MENTION THE ELEVATED FIRE DANGER IN THE HWO AND FWF THRU MID
AFTERNOON BEFORE INCREASING RH VALUES AND DEVELOPING PRECIP BRINGS A
CLOSE TO OUR DRY SPELL.

&&

.SHORT TERM...(MONDAY THROUGH TUESDAY NIGHT)
ISSUED AT 237 AM EDT SUN APR 19 2015

HIGH IMPACT WEATHER POTENTIAL: NOTHING SIGNIFICANT

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: NO SURPRISES WITH LATEST AND
GREATEST GUIDANCE TRENDS...WITH ROCK STEADY INTRA/INTER MODEL AND
ENSEMBLE SOLUTIONS SHOWING THE DEVELOPMENT...AND SUBSEQUENT SLOW
MOVEMENT...OF DEEP CLOSED LOW PRESSURE ACROSS THE FAR NORTHERN LAKES
THIS UPCOMING WEEK. ATTENDANT COLD CORE ANOMALIES/STEEP MID LEVEL
LAPSE RATES AND ENERGY PINWHEELING AROUND PARENT SYSTEM WILL BRING
BELOW NORMAL TEMPERATURES AND PERIODS OF SHOWERS...WHICH AT TIMES
WILL NOT BE OF THE LIQUID VARIETY. TRENDS LOOK DRIER BY LATE IN THE
WEEK INTO THE START OF NEXT WEEKEND...ALTHOUGH WITH STILL BELOW
NORMAL TEMPERATURES.

PRIMARY FORECAST CONCERNS/CHALLENGES: NO CHANGE FROM EARLIER...WITH
TEMPERATURE TRENDS AND PRECIP TIMING/COVERAGE/AND TYPE CONCERNS
DOMINATING MUCH OF THE FORECAST.

DETAILS: AMPLIFICATION PROCESSES KICKS INTO OVERDRIVE TO START THE
WEEK AS STRONG NORTHERN STREAM ENERGY DIVES INTO THE UPPER
MISSISSIPPI VALLEY. SUNDAY NIGHT`S WIDESPREAD RAIN PRODUCING SOUTHERN
STREAM WAVE LOOKS TO EXIT NORTHEAST OF OUR AREA MONDAY
MORNING...QUICKLY FOLLOWED BY REMNANTS OF CURRENT WESTERN KANSAS
SHORTWAVE AS IT BECOMES ABSORBED INTO STRONGER NORTHERN STREAM
TROUGH. STILL SOME QUESTION WITH LOCATION OF BETTER FORCING WITH
THIS LATTER FEATURE...BUT EITHER WAY...LOOKS LIKE SHOWERS A PRETTY
SAFE BET.

MONDAY NIGHT - TUESDAY NIGHT WEATHER DOMINATED BY THAT DEEPENING AND
INCREASINGLY CLOSED OFF UPPER/MID LEVEL LOW AS IT SLOWLY MEANDERS
ACROSS THE FAR NORTHERN LAKES. HINTS MUCH OF THE AREA ACTUALLY MIGHT
CATCH A BREAK MONDAY NIGHT...WAITING FOR DEEPER "WRAP AROUND"
MOISTURE TO WORK BACK INTO THE REGION TUESDAY AND TUESDAY NIGHT. H8
TEMPERATURES FALLING SEVERAL DEGREES BELOW ZERO AND STEEP LOW LEVEL
LAPSE RATES ARGUES ANY SURFACE BASED MELTING LAYER TUESDAY COULD BE
QUICKLY OVERCOME...SUPPORTING PRIMARILY SNOW SHOWERS WHEN
PRECIPITATION FALLS HEAVIEST. THIS SHOULD ESPECIALLY BE TRUE FAR
NORTH AND ACROSS INTERIOR HIGHER LOCALES. MELTING LAYER IS LOST FOR
MOST TUESDAY NIGHT...SUGGESTING MAINLY SNOW. PRECIP LOOKS
SHOWERY...DRIVEN IN LARGE PART FROM DIURNAL TRENDS AND PASSING MID
LEVEL SUPPORT. COULD SEE SOME ENHANCED FOCUS INTO NORTHWEST LOWER
WITH PERSISTENT MOIST UPSLOPE FLOW WITHIN WEST TO NORTHWEST WINDS.
SUPPOSE SOME LIGHT ACCUMULATIONS ARE POSSIBLE IN THIS AREA...BUT
DEFINITELY NOT ENOUGH TO WARRANT ANY MENTION IN OUR HAZARDOUS
WEATHER PRODUCTS.

&&

.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 237 AM EDT SUN APR 19 2015

REALLY NOT A WHOLE LOT OF
CHANGE EXPECTED TO START THIS PERIOD...WITH DIURNAL ENHANCEMENT AND
PASSING WAVES SUPPORTING MORE RAIN/SNOW SHOWERS RIGHT THROUGH
THURSDAY. REALLY HATE TO SAY THIS...BUT EVEN HINTS OVERHEAD AIR MAY
BE JUST COLD ENOUGH TO SUPPORT SOME MARGINAL LAKE ENHANCEMENT...
ESPECIALLY NOW WITH MOSTLY ICE-FREE CONDITIONS. SHOULDN`T BE TOO BIG
A DEAL IF THIS DOES OCCUR...AND PER LATE SPRING USUAL..."MOST" WOULD
OCCUR WEDNESDAY NIGHT WHEN DIURNAL DISRUPTION IS MINIMIZED.

WHILE DETAILS ARE ELUDING WITH RESPECT TO JUST HOW FAST SYSTEM
PUSHES OFF TO THE EAST...CANNOT FIND A COMPELLING REASON TO DEVIATE
FROM INHERITED DRY FORECAST THURSDAY NIGHT RIGHT THROUGH SATURDAY.
DEFINITELY PLAUSIBLE TROUGHING WILL REMAIN CLOSE ENOUGH TO ALLOW
ADDITIONAL WAVES/ATTENDANT SHOWERS TO PASS OVERHEAD. STILL HAVE
PLENTY OF TIME TO WATCH HOW THIS ALL UNFOLDS. EITHER WAY...COOL
CONDITIONS WILL NOT BE SO EASILY SCOURED OUT...WITH BELOW NORMAL
TEMPERATURES CONTINUING INTO THE START OF THE WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 142 PM EDT SUN APR 19 2015

MOISTURE HAS BEEN SLOW TO MOVE INTO THE REGION THIS AFTERNOON, AND
THUS, HAVE BEEN SLOWING DOWN THE TIMING OF THE RAIN. BEST GUESS AT
THIS POINT IN THE AFTERNOON, IS THAT IT SHOWS UP AROUND 23Z AT
MBL/TVC AREA, AND ABOUT 00Z AT APN/PLN. AFTER THAT THE VSBY LOOKS
TO FALL INTO THE MVFR CATEGORY, BUT THE CIGS BY 12Z/MON FALL TO
IFR AS THE LOW MOVES OVER US AND BRINGS MORE MOISTURE OVER THE
REGION.

&&

.MARINE...
ISSUED AT 237 AM EDT SUN APR 19 2015

LOW PRESSURE WILL LIFT NE INTO MICHIGAN TONIGHT...PRODUCING
WIDESPREAD RAIN ACROSS OUR ENTIRE NEARSHORE AREA. STRENGTHENING
EAST/SOUTHEAST WINDS AHEAD OF THAT SYSTEM TODAY AND TONIGHT WILL
LEAD TO SCA CONDITIONS FOR MUCH OF OUR NEARSHORE AREA...WITH WIND
GUSTS OF 15 TO 25 KTS EXPECTED. THE EXCEPTION WILL BE THE LAKE
MICHIGAN SHORELINE FROM MANISTEE TO THE BRIDGE...WHICH SHOULD FALL
JUST SHORT OF SCA CRITERIA.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LSZ321-322.

&&

$$

UPDATE...JSL
NEAR TERM...MLR
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...JSL
MARINE...MLR



000
FXUS63 KAPX 191748
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
148 PM EDT SUN APR 19 2015

.UPDATE...
ISSUED AT 1249 PM EDT SUN APR 19 2015

LOOKS LIKE THE MOISTURE IS SLOW INTO MOVING INTO THE REGION. SO
HAVE SLOWED DOWN THE PROGRESSION OF THE RAIN CONSIDERABLY. THE
CHANCE OF RAIN AREA IS NOW JUST GETTING TO M-55 BY 21Z INSTEAD OF
UP M-32. THIS IS BASED BOTH BY THE CURRENT OBS AND THE LATEST
GFS/NAM WITH THE RAP13 EVEN SLOWER. ALL OF THE MODELS AGREE THAT
THE RAIN SHOULD BE INTO E UPPER BY 06Z. SO WILL HOLD ONTO THAT
IDEA FOR NOW.

UPDATE ISSUED AT 952 AM EDT SUN APR 19 2015

HUDSON BAY HIGH IS SLOWLY MOVING EAST AND ALLOWING THE DEVELOPING
LOW PRESSURE SYSTEM IN THE CENTRAL PLAINS TO SLIDE INTO THE UPPER
GREAT LAKES. THE MAIN CONCERN FOR THE AFTERNOON, IS THE TIMING OF
THE RAIN START OR IF THE DRY AIR WILL CONTINUE A LITTLE LONGER.
BESIDES SLOWING THE RAIN START, THE DRY AIR COULD ALSO CAUSE AN
EXTENDED FIRE WEATHER CONCERN. HOWEVER, WITH THE CLOUDS
INCREASING, AND THE MOISTURE EXPECTED TO INCREASE WILL CONTINUE
WITH THE GOING FORECAST. WILL PROBABLY UPDATE THIS DISCUSSION
AROUND 1PM TO TALK ABOUT TIMING THEN AS WELL.

&&

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 237 AM EDT SUN APR 19 2015

STRONG HIGH PRESSURE CENTERED NE OF MICHIGAN REMAINS FIRMLY IN
CONTROL OF OUR WEATHER EARLY THIS MORNING...WITH MAINLY CLEAR SKIES
STILL OVERHEAD. HIGH CLOUD SHIELD ALONG THE NRN FRINGE OF INCREASING
MOISTURE HAS REACHED SRN LWR MICHIGAN...WELL NORTH OF DEVELOPING LOW
PRESSURE OVER THE MID MISSISSIPPI VALLEY. THIS LOW WILL GRADUALLY
DEEPEN AS IT LIFTS NE INTO LWR MICHIGAN TONIGHT...REACHING SAGINAW
BAY AND NE LWR MICHIGAN BY 12Z MONDAY. WIDESPREAD RAIN WILL DEVELOP
FROM SOUTH TO NORTH BEGINNING LATE AFTERNOON/EARLY EVENING...WITH
WIDESPREAD RAIN THEN CONTINUING FOR THE REMAINDER OF THE NIGHT AS
DEEP MOISTURE AND STRONG 700-500 MB LEVEL OMEGA LIFT INTO THE AREA
ALONG AND AHEAD OF THE SURFACE LOW CENTER.

IN THE MEANTIME...THE ONLY REAL CONCERN FOR TODAY IS THE POTENTIAL
FOR ONE MORE DAY OF ELEVATED FIRE DANGER GIVEN RECENT PERSISTENT DRY
CONDITIONS PRIOR TO GREEN UP. MINIMUM RH VALUES WILL LIKELY FALL
INTO THE MID TO UPPER 20S ACROSS INLAND AREAS OF NW LWR MICHIGAN BY
EARLY AFTERNOON BEFORE LOW LEVEL MOISTURE/RH BEGINS TO INCREASE IN
ADVANCE OF PRECIP DEVELOPMENT. TEMPS WILL BE SLIGHTLY COOLER
TODAY...WITH HIGHS MAINLY IN THE MID 50S TO LOWER 60S. HOWEVER...
E/SE SURFACE WINDS WILL QUICKLY STRENGTHEN TODAY UPON COMMENCEMENT
OF DAYTIME MIXING...WITH GUSTS OF 15 TO 25 MPH EXPECTED. GIVEN THE
GUSTY WINDS AND LOWER RH VALUES (ESPECIALLY EARLY AFTERNOON)...WILL
AGAIN MENTION THE ELEVATED FIRE DANGER IN THE HWO AND FWF THRU MID
AFTERNOON BEFORE INCREASING RH VALUES AND DEVELOPING PRECIP BRINGS A
CLOSE TO OUR DRY SPELL.

&&

.SHORT TERM...(MONDAY THROUGH TUESDAY NIGHT)
ISSUED AT 237 AM EDT SUN APR 19 2015

HIGH IMPACT WEATHER POTENTIAL: NOTHING SIGNIFICANT

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: NO SURPRISES WITH LATEST AND
GREATEST GUIDANCE TRENDS...WITH ROCK STEADY INTRA/INTER MODEL AND
ENSEMBLE SOLUTIONS SHOWING THE DEVELOPMENT...AND SUBSEQUENT SLOW
MOVEMENT...OF DEEP CLOSED LOW PRESSURE ACROSS THE FAR NORTHERN LAKES
THIS UPCOMING WEEK. ATTENDANT COLD CORE ANOMALIES/STEEP MID LEVEL
LAPSE RATES AND ENERGY PINWHEELING AROUND PARENT SYSTEM WILL BRING
BELOW NORMAL TEMPERATURES AND PERIODS OF SHOWERS...WHICH AT TIMES
WILL NOT BE OF THE LIQUID VARIETY. TRENDS LOOK DRIER BY LATE IN THE
WEEK INTO THE START OF NEXT WEEKEND...ALTHOUGH WITH STILL BELOW
NORMAL TEMPERATURES.

PRIMARY FORECAST CONCERNS/CHALLENGES: NO CHANGE FROM EARLIER...WITH
TEMPERATURE TRENDS AND PRECIP TIMING/COVERAGE/AND TYPE CONCERNS
DOMINATING MUCH OF THE FORECAST.

DETAILS: AMPLIFICATION PROCESSES KICKS INTO OVERDRIVE TO START THE
WEEK AS STRONG NORTHERN STREAM ENERGY DIVES INTO THE UPPER
MISSISSIPPI VALLEY. SUNDAY NIGHT`S WIDESPREAD RAIN PRODUCING SOUTHERN
STREAM WAVE LOOKS TO EXIT NORTHEAST OF OUR AREA MONDAY
MORNING...QUICKLY FOLLOWED BY REMNANTS OF CURRENT WESTERN KANSAS
SHORTWAVE AS IT BECOMES ABSORBED INTO STRONGER NORTHERN STREAM
TROUGH. STILL SOME QUESTION WITH LOCATION OF BETTER FORCING WITH
THIS LATTER FEATURE...BUT EITHER WAY...LOOKS LIKE SHOWERS A PRETTY
SAFE BET.

MONDAY NIGHT - TUESDAY NIGHT WEATHER DOMINATED BY THAT DEEPENING AND
INCREASINGLY CLOSED OFF UPPER/MID LEVEL LOW AS IT SLOWLY MEANDERS
ACROSS THE FAR NORTHERN LAKES. HINTS MUCH OF THE AREA ACTUALLY MIGHT
CATCH A BREAK MONDAY NIGHT...WAITING FOR DEEPER "WRAP AROUND"
MOISTURE TO WORK BACK INTO THE REGION TUESDAY AND TUESDAY NIGHT. H8
TEMPERATURES FALLING SEVERAL DEGREES BELOW ZERO AND STEEP LOW LEVEL
LAPSE RATES ARGUES ANY SURFACE BASED MELTING LAYER TUESDAY COULD BE
QUICKLY OVERCOME...SUPPORTING PRIMARILY SNOW SHOWERS WHEN
PRECIPITATION FALLS HEAVIEST. THIS SHOULD ESPECIALLY BE TRUE FAR
NORTH AND ACROSS INTERIOR HIGHER LOCALES. MELTING LAYER IS LOST FOR
MOST TUESDAY NIGHT...SUGGESTING MAINLY SNOW. PRECIP LOOKS
SHOWERY...DRIVEN IN LARGE PART FROM DIURNAL TRENDS AND PASSING MID
LEVEL SUPPORT. COULD SEE SOME ENHANCED FOCUS INTO NORTHWEST LOWER
WITH PERSISTENT MOIST UPSLOPE FLOW WITHIN WEST TO NORTHWEST WINDS.
SUPPOSE SOME LIGHT ACCUMULATIONS ARE POSSIBLE IN THIS AREA...BUT
DEFINITELY NOT ENOUGH TO WARRANT ANY MENTION IN OUR HAZARDOUS
WEATHER PRODUCTS.

&&

.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 237 AM EDT SUN APR 19 2015

REALLY NOT A WHOLE LOT OF
CHANGE EXPECTED TO START THIS PERIOD...WITH DIURNAL ENHANCEMENT AND
PASSING WAVES SUPPORTING MORE RAIN/SNOW SHOWERS RIGHT THROUGH
THURSDAY. REALLY HATE TO SAY THIS...BUT EVEN HINTS OVERHEAD AIR MAY
BE JUST COLD ENOUGH TO SUPPORT SOME MARGINAL LAKE ENHANCEMENT...
ESPECIALLY NOW WITH MOSTLY ICE-FREE CONDITIONS. SHOULDN`T BE TOO BIG
A DEAL IF THIS DOES OCCUR...AND PER LATE SPRING USUAL..."MOST" WOULD
OCCUR WEDNESDAY NIGHT WHEN DIURNAL DISRUPTION IS MINIMIZED.

WHILE DETAILS ARE ELUDING WITH RESPECT TO JUST HOW FAST SYSTEM
PUSHES OFF TO THE EAST...CANNOT FIND A COMPELLING REASON TO DEVIATE
FROM INHERITED DRY FORECAST THURSDAY NIGHT RIGHT THROUGH SATURDAY.
DEFINITELY PLAUSIBLE TROUGHING WILL REMAIN CLOSE ENOUGH TO ALLOW
ADDITIONAL WAVES/ATTENDANT SHOWERS TO PASS OVERHEAD. STILL HAVE
PLENTY OF TIME TO WATCH HOW THIS ALL UNFOLDS. EITHER WAY...COOL
CONDITIONS WILL NOT BE SO EASILY SCOURED OUT...WITH BELOW NORMAL
TEMPERATURES CONTINUING INTO THE START OF THE WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 142 PM EDT SUN APR 19 2015

MOISTURE HAS BEEN SLOW TO MOVE INTO THE REGION THIS AFTERNOON, AND
THUS, HAVE BEEN SLOWING DOWN THE TIMING OF THE RAIN. BEST GUESS AT
THIS POINT IN THE AFTERNOON, IS THAT IT SHOWS UP AROUND 23Z AT
MBL/TVC AREA, AND ABOUT 00Z AT APN/PLN. AFTER THAT THE VSBY LOOKS
TO FALL INTO THE MVFR CATEGORY, BUT THE CIGS BY 12Z/MON FALL TO
IFR AS THE LOW MOVES OVER US AND BRINGS MORE MOISTURE OVER THE
REGION.

&&

.MARINE...
ISSUED AT 237 AM EDT SUN APR 19 2015

LOW PRESSURE WILL LIFT NE INTO MICHIGAN TONIGHT...PRODUCING
WIDESPREAD RAIN ACROSS OUR ENTIRE NEARSHORE AREA. STRENGTHENING
EAST/SOUTHEAST WINDS AHEAD OF THAT SYSTEM TODAY AND TONIGHT WILL
LEAD TO SCA CONDITIONS FOR MUCH OF OUR NEARSHORE AREA...WITH WIND
GUSTS OF 15 TO 25 KTS EXPECTED. THE EXCEPTION WILL BE THE LAKE
MICHIGAN SHORELINE FROM MANISTEE TO THE BRIDGE...WHICH SHOULD FALL
JUST SHORT OF SCA CRITERIA.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LSZ321-322.

&&

$$

UPDATE...JSL
NEAR TERM...MLR
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...JSL
MARINE...MLR



000
FXUS63 KAPX 191748
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
148 PM EDT SUN APR 19 2015

.UPDATE...
ISSUED AT 1249 PM EDT SUN APR 19 2015

LOOKS LIKE THE MOISTURE IS SLOW INTO MOVING INTO THE REGION. SO
HAVE SLOWED DOWN THE PROGRESSION OF THE RAIN CONSIDERABLY. THE
CHANCE OF RAIN AREA IS NOW JUST GETTING TO M-55 BY 21Z INSTEAD OF
UP M-32. THIS IS BASED BOTH BY THE CURRENT OBS AND THE LATEST
GFS/NAM WITH THE RAP13 EVEN SLOWER. ALL OF THE MODELS AGREE THAT
THE RAIN SHOULD BE INTO E UPPER BY 06Z. SO WILL HOLD ONTO THAT
IDEA FOR NOW.

UPDATE ISSUED AT 952 AM EDT SUN APR 19 2015

HUDSON BAY HIGH IS SLOWLY MOVING EAST AND ALLOWING THE DEVELOPING
LOW PRESSURE SYSTEM IN THE CENTRAL PLAINS TO SLIDE INTO THE UPPER
GREAT LAKES. THE MAIN CONCERN FOR THE AFTERNOON, IS THE TIMING OF
THE RAIN START OR IF THE DRY AIR WILL CONTINUE A LITTLE LONGER.
BESIDES SLOWING THE RAIN START, THE DRY AIR COULD ALSO CAUSE AN
EXTENDED FIRE WEATHER CONCERN. HOWEVER, WITH THE CLOUDS
INCREASING, AND THE MOISTURE EXPECTED TO INCREASE WILL CONTINUE
WITH THE GOING FORECAST. WILL PROBABLY UPDATE THIS DISCUSSION
AROUND 1PM TO TALK ABOUT TIMING THEN AS WELL.

&&

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 237 AM EDT SUN APR 19 2015

STRONG HIGH PRESSURE CENTERED NE OF MICHIGAN REMAINS FIRMLY IN
CONTROL OF OUR WEATHER EARLY THIS MORNING...WITH MAINLY CLEAR SKIES
STILL OVERHEAD. HIGH CLOUD SHIELD ALONG THE NRN FRINGE OF INCREASING
MOISTURE HAS REACHED SRN LWR MICHIGAN...WELL NORTH OF DEVELOPING LOW
PRESSURE OVER THE MID MISSISSIPPI VALLEY. THIS LOW WILL GRADUALLY
DEEPEN AS IT LIFTS NE INTO LWR MICHIGAN TONIGHT...REACHING SAGINAW
BAY AND NE LWR MICHIGAN BY 12Z MONDAY. WIDESPREAD RAIN WILL DEVELOP
FROM SOUTH TO NORTH BEGINNING LATE AFTERNOON/EARLY EVENING...WITH
WIDESPREAD RAIN THEN CONTINUING FOR THE REMAINDER OF THE NIGHT AS
DEEP MOISTURE AND STRONG 700-500 MB LEVEL OMEGA LIFT INTO THE AREA
ALONG AND AHEAD OF THE SURFACE LOW CENTER.

IN THE MEANTIME...THE ONLY REAL CONCERN FOR TODAY IS THE POTENTIAL
FOR ONE MORE DAY OF ELEVATED FIRE DANGER GIVEN RECENT PERSISTENT DRY
CONDITIONS PRIOR TO GREEN UP. MINIMUM RH VALUES WILL LIKELY FALL
INTO THE MID TO UPPER 20S ACROSS INLAND AREAS OF NW LWR MICHIGAN BY
EARLY AFTERNOON BEFORE LOW LEVEL MOISTURE/RH BEGINS TO INCREASE IN
ADVANCE OF PRECIP DEVELOPMENT. TEMPS WILL BE SLIGHTLY COOLER
TODAY...WITH HIGHS MAINLY IN THE MID 50S TO LOWER 60S. HOWEVER...
E/SE SURFACE WINDS WILL QUICKLY STRENGTHEN TODAY UPON COMMENCEMENT
OF DAYTIME MIXING...WITH GUSTS OF 15 TO 25 MPH EXPECTED. GIVEN THE
GUSTY WINDS AND LOWER RH VALUES (ESPECIALLY EARLY AFTERNOON)...WILL
AGAIN MENTION THE ELEVATED FIRE DANGER IN THE HWO AND FWF THRU MID
AFTERNOON BEFORE INCREASING RH VALUES AND DEVELOPING PRECIP BRINGS A
CLOSE TO OUR DRY SPELL.

&&

.SHORT TERM...(MONDAY THROUGH TUESDAY NIGHT)
ISSUED AT 237 AM EDT SUN APR 19 2015

HIGH IMPACT WEATHER POTENTIAL: NOTHING SIGNIFICANT

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: NO SURPRISES WITH LATEST AND
GREATEST GUIDANCE TRENDS...WITH ROCK STEADY INTRA/INTER MODEL AND
ENSEMBLE SOLUTIONS SHOWING THE DEVELOPMENT...AND SUBSEQUENT SLOW
MOVEMENT...OF DEEP CLOSED LOW PRESSURE ACROSS THE FAR NORTHERN LAKES
THIS UPCOMING WEEK. ATTENDANT COLD CORE ANOMALIES/STEEP MID LEVEL
LAPSE RATES AND ENERGY PINWHEELING AROUND PARENT SYSTEM WILL BRING
BELOW NORMAL TEMPERATURES AND PERIODS OF SHOWERS...WHICH AT TIMES
WILL NOT BE OF THE LIQUID VARIETY. TRENDS LOOK DRIER BY LATE IN THE
WEEK INTO THE START OF NEXT WEEKEND...ALTHOUGH WITH STILL BELOW
NORMAL TEMPERATURES.

PRIMARY FORECAST CONCERNS/CHALLENGES: NO CHANGE FROM EARLIER...WITH
TEMPERATURE TRENDS AND PRECIP TIMING/COVERAGE/AND TYPE CONCERNS
DOMINATING MUCH OF THE FORECAST.

DETAILS: AMPLIFICATION PROCESSES KICKS INTO OVERDRIVE TO START THE
WEEK AS STRONG NORTHERN STREAM ENERGY DIVES INTO THE UPPER
MISSISSIPPI VALLEY. SUNDAY NIGHT`S WIDESPREAD RAIN PRODUCING SOUTHERN
STREAM WAVE LOOKS TO EXIT NORTHEAST OF OUR AREA MONDAY
MORNING...QUICKLY FOLLOWED BY REMNANTS OF CURRENT WESTERN KANSAS
SHORTWAVE AS IT BECOMES ABSORBED INTO STRONGER NORTHERN STREAM
TROUGH. STILL SOME QUESTION WITH LOCATION OF BETTER FORCING WITH
THIS LATTER FEATURE...BUT EITHER WAY...LOOKS LIKE SHOWERS A PRETTY
SAFE BET.

MONDAY NIGHT - TUESDAY NIGHT WEATHER DOMINATED BY THAT DEEPENING AND
INCREASINGLY CLOSED OFF UPPER/MID LEVEL LOW AS IT SLOWLY MEANDERS
ACROSS THE FAR NORTHERN LAKES. HINTS MUCH OF THE AREA ACTUALLY MIGHT
CATCH A BREAK MONDAY NIGHT...WAITING FOR DEEPER "WRAP AROUND"
MOISTURE TO WORK BACK INTO THE REGION TUESDAY AND TUESDAY NIGHT. H8
TEMPERATURES FALLING SEVERAL DEGREES BELOW ZERO AND STEEP LOW LEVEL
LAPSE RATES ARGUES ANY SURFACE BASED MELTING LAYER TUESDAY COULD BE
QUICKLY OVERCOME...SUPPORTING PRIMARILY SNOW SHOWERS WHEN
PRECIPITATION FALLS HEAVIEST. THIS SHOULD ESPECIALLY BE TRUE FAR
NORTH AND ACROSS INTERIOR HIGHER LOCALES. MELTING LAYER IS LOST FOR
MOST TUESDAY NIGHT...SUGGESTING MAINLY SNOW. PRECIP LOOKS
SHOWERY...DRIVEN IN LARGE PART FROM DIURNAL TRENDS AND PASSING MID
LEVEL SUPPORT. COULD SEE SOME ENHANCED FOCUS INTO NORTHWEST LOWER
WITH PERSISTENT MOIST UPSLOPE FLOW WITHIN WEST TO NORTHWEST WINDS.
SUPPOSE SOME LIGHT ACCUMULATIONS ARE POSSIBLE IN THIS AREA...BUT
DEFINITELY NOT ENOUGH TO WARRANT ANY MENTION IN OUR HAZARDOUS
WEATHER PRODUCTS.

&&

.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 237 AM EDT SUN APR 19 2015

REALLY NOT A WHOLE LOT OF
CHANGE EXPECTED TO START THIS PERIOD...WITH DIURNAL ENHANCEMENT AND
PASSING WAVES SUPPORTING MORE RAIN/SNOW SHOWERS RIGHT THROUGH
THURSDAY. REALLY HATE TO SAY THIS...BUT EVEN HINTS OVERHEAD AIR MAY
BE JUST COLD ENOUGH TO SUPPORT SOME MARGINAL LAKE ENHANCEMENT...
ESPECIALLY NOW WITH MOSTLY ICE-FREE CONDITIONS. SHOULDN`T BE TOO BIG
A DEAL IF THIS DOES OCCUR...AND PER LATE SPRING USUAL..."MOST" WOULD
OCCUR WEDNESDAY NIGHT WHEN DIURNAL DISRUPTION IS MINIMIZED.

WHILE DETAILS ARE ELUDING WITH RESPECT TO JUST HOW FAST SYSTEM
PUSHES OFF TO THE EAST...CANNOT FIND A COMPELLING REASON TO DEVIATE
FROM INHERITED DRY FORECAST THURSDAY NIGHT RIGHT THROUGH SATURDAY.
DEFINITELY PLAUSIBLE TROUGHING WILL REMAIN CLOSE ENOUGH TO ALLOW
ADDITIONAL WAVES/ATTENDANT SHOWERS TO PASS OVERHEAD. STILL HAVE
PLENTY OF TIME TO WATCH HOW THIS ALL UNFOLDS. EITHER WAY...COOL
CONDITIONS WILL NOT BE SO EASILY SCOURED OUT...WITH BELOW NORMAL
TEMPERATURES CONTINUING INTO THE START OF THE WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 142 PM EDT SUN APR 19 2015

MOISTURE HAS BEEN SLOW TO MOVE INTO THE REGION THIS AFTERNOON, AND
THUS, HAVE BEEN SLOWING DOWN THE TIMING OF THE RAIN. BEST GUESS AT
THIS POINT IN THE AFTERNOON, IS THAT IT SHOWS UP AROUND 23Z AT
MBL/TVC AREA, AND ABOUT 00Z AT APN/PLN. AFTER THAT THE VSBY LOOKS
TO FALL INTO THE MVFR CATEGORY, BUT THE CIGS BY 12Z/MON FALL TO
IFR AS THE LOW MOVES OVER US AND BRINGS MORE MOISTURE OVER THE
REGION.

&&

.MARINE...
ISSUED AT 237 AM EDT SUN APR 19 2015

LOW PRESSURE WILL LIFT NE INTO MICHIGAN TONIGHT...PRODUCING
WIDESPREAD RAIN ACROSS OUR ENTIRE NEARSHORE AREA. STRENGTHENING
EAST/SOUTHEAST WINDS AHEAD OF THAT SYSTEM TODAY AND TONIGHT WILL
LEAD TO SCA CONDITIONS FOR MUCH OF OUR NEARSHORE AREA...WITH WIND
GUSTS OF 15 TO 25 KTS EXPECTED. THE EXCEPTION WILL BE THE LAKE
MICHIGAN SHORELINE FROM MANISTEE TO THE BRIDGE...WHICH SHOULD FALL
JUST SHORT OF SCA CRITERIA.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LSZ321-322.

&&

$$

UPDATE...JSL
NEAR TERM...MLR
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...JSL
MARINE...MLR




000
FXUS63 KAPX 191748
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
148 PM EDT SUN APR 19 2015

.UPDATE...
ISSUED AT 1249 PM EDT SUN APR 19 2015

LOOKS LIKE THE MOISTURE IS SLOW INTO MOVING INTO THE REGION. SO
HAVE SLOWED DOWN THE PROGRESSION OF THE RAIN CONSIDERABLY. THE
CHANCE OF RAIN AREA IS NOW JUST GETTING TO M-55 BY 21Z INSTEAD OF
UP M-32. THIS IS BASED BOTH BY THE CURRENT OBS AND THE LATEST
GFS/NAM WITH THE RAP13 EVEN SLOWER. ALL OF THE MODELS AGREE THAT
THE RAIN SHOULD BE INTO E UPPER BY 06Z. SO WILL HOLD ONTO THAT
IDEA FOR NOW.

UPDATE ISSUED AT 952 AM EDT SUN APR 19 2015

HUDSON BAY HIGH IS SLOWLY MOVING EAST AND ALLOWING THE DEVELOPING
LOW PRESSURE SYSTEM IN THE CENTRAL PLAINS TO SLIDE INTO THE UPPER
GREAT LAKES. THE MAIN CONCERN FOR THE AFTERNOON, IS THE TIMING OF
THE RAIN START OR IF THE DRY AIR WILL CONTINUE A LITTLE LONGER.
BESIDES SLOWING THE RAIN START, THE DRY AIR COULD ALSO CAUSE AN
EXTENDED FIRE WEATHER CONCERN. HOWEVER, WITH THE CLOUDS
INCREASING, AND THE MOISTURE EXPECTED TO INCREASE WILL CONTINUE
WITH THE GOING FORECAST. WILL PROBABLY UPDATE THIS DISCUSSION
AROUND 1PM TO TALK ABOUT TIMING THEN AS WELL.

&&

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 237 AM EDT SUN APR 19 2015

STRONG HIGH PRESSURE CENTERED NE OF MICHIGAN REMAINS FIRMLY IN
CONTROL OF OUR WEATHER EARLY THIS MORNING...WITH MAINLY CLEAR SKIES
STILL OVERHEAD. HIGH CLOUD SHIELD ALONG THE NRN FRINGE OF INCREASING
MOISTURE HAS REACHED SRN LWR MICHIGAN...WELL NORTH OF DEVELOPING LOW
PRESSURE OVER THE MID MISSISSIPPI VALLEY. THIS LOW WILL GRADUALLY
DEEPEN AS IT LIFTS NE INTO LWR MICHIGAN TONIGHT...REACHING SAGINAW
BAY AND NE LWR MICHIGAN BY 12Z MONDAY. WIDESPREAD RAIN WILL DEVELOP
FROM SOUTH TO NORTH BEGINNING LATE AFTERNOON/EARLY EVENING...WITH
WIDESPREAD RAIN THEN CONTINUING FOR THE REMAINDER OF THE NIGHT AS
DEEP MOISTURE AND STRONG 700-500 MB LEVEL OMEGA LIFT INTO THE AREA
ALONG AND AHEAD OF THE SURFACE LOW CENTER.

IN THE MEANTIME...THE ONLY REAL CONCERN FOR TODAY IS THE POTENTIAL
FOR ONE MORE DAY OF ELEVATED FIRE DANGER GIVEN RECENT PERSISTENT DRY
CONDITIONS PRIOR TO GREEN UP. MINIMUM RH VALUES WILL LIKELY FALL
INTO THE MID TO UPPER 20S ACROSS INLAND AREAS OF NW LWR MICHIGAN BY
EARLY AFTERNOON BEFORE LOW LEVEL MOISTURE/RH BEGINS TO INCREASE IN
ADVANCE OF PRECIP DEVELOPMENT. TEMPS WILL BE SLIGHTLY COOLER
TODAY...WITH HIGHS MAINLY IN THE MID 50S TO LOWER 60S. HOWEVER...
E/SE SURFACE WINDS WILL QUICKLY STRENGTHEN TODAY UPON COMMENCEMENT
OF DAYTIME MIXING...WITH GUSTS OF 15 TO 25 MPH EXPECTED. GIVEN THE
GUSTY WINDS AND LOWER RH VALUES (ESPECIALLY EARLY AFTERNOON)...WILL
AGAIN MENTION THE ELEVATED FIRE DANGER IN THE HWO AND FWF THRU MID
AFTERNOON BEFORE INCREASING RH VALUES AND DEVELOPING PRECIP BRINGS A
CLOSE TO OUR DRY SPELL.

&&

.SHORT TERM...(MONDAY THROUGH TUESDAY NIGHT)
ISSUED AT 237 AM EDT SUN APR 19 2015

HIGH IMPACT WEATHER POTENTIAL: NOTHING SIGNIFICANT

PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: NO SURPRISES WITH LATEST AND
GREATEST GUIDANCE TRENDS...WITH ROCK STEADY INTRA/INTER MODEL AND
ENSEMBLE SOLUTIONS SHOWING THE DEVELOPMENT...AND SUBSEQUENT SLOW
MOVEMENT...OF DEEP CLOSED LOW PRESSURE ACROSS THE FAR NORTHERN LAKES
THIS UPCOMING WEEK. ATTENDANT COLD CORE ANOMALIES/STEEP MID LEVEL
LAPSE RATES AND ENERGY PINWHEELING AROUND PARENT SYSTEM WILL BRING
BELOW NORMAL TEMPERATURES AND PERIODS OF SHOWERS...WHICH AT TIMES
WILL NOT BE OF THE LIQUID VARIETY. TRENDS LOOK DRIER BY LATE IN THE
WEEK INTO THE START OF NEXT WEEKEND...ALTHOUGH WITH STILL BELOW
NORMAL TEMPERATURES.

PRIMARY FORECAST CONCERNS/CHALLENGES: NO CHANGE FROM EARLIER...WITH
TEMPERATURE TRENDS AND PRECIP TIMING/COVERAGE/AND TYPE CONCERNS
DOMINATING MUCH OF THE FORECAST.

DETAILS: AMPLIFICATION PROCESSES KICKS INTO OVERDRIVE TO START THE
WEEK AS STRONG NORTHERN STREAM ENERGY DIVES INTO THE UPPER
MISSISSIPPI VALLEY. SUNDAY NIGHT`S WIDESPREAD RAIN PRODUCING SOUTHERN
STREAM WAVE LOOKS TO EXIT NORTHEAST OF OUR AREA MONDAY
MORNING...QUICKLY FOLLOWED BY REMNANTS OF CURRENT WESTERN KANSAS
SHORTWAVE AS IT BECOMES ABSORBED INTO STRONGER NORTHERN STREAM
TROUGH. STILL SOME QUESTION WITH LOCATION OF BETTER FORCING WITH
THIS LATTER FEATURE...BUT EITHER WAY...LOOKS LIKE SHOWERS A PRETTY
SAFE BET.

MONDAY NIGHT - TUESDAY NIGHT WEATHER DOMINATED BY THAT DEEPENING AND
INCREASINGLY CLOSED OFF UPPER/MID LEVEL LOW AS IT SLOWLY MEANDERS
ACROSS THE FAR NORTHERN LAKES. HINTS MUCH OF THE AREA ACTUALLY MIGHT
CATCH A BREAK MONDAY NIGHT...WAITING FOR DEEPER "WRAP AROUND"
MOISTURE TO WORK BACK INTO THE REGION TUESDAY AND TUESDAY NIGHT. H8
TEMPERATURES FALLING SEVERAL DEGREES BELOW ZERO AND STEEP LOW LEVEL
LAPSE RATES ARGUES ANY SURFACE BASED MELTING LAYER TUESDAY COULD BE
QUICKLY OVERCOME...SUPPORTING PRIMARILY SNOW SHOWERS WHEN
PRECIPITATION FALLS HEAVIEST. THIS SHOULD ESPECIALLY BE TRUE FAR
NORTH AND ACROSS INTERIOR HIGHER LOCALES. MELTING LAYER IS LOST FOR
MOST TUESDAY NIGHT...SUGGESTING MAINLY SNOW. PRECIP LOOKS
SHOWERY...DRIVEN IN LARGE PART FROM DIURNAL TRENDS AND PASSING MID
LEVEL SUPPORT. COULD SEE SOME ENHANCED FOCUS INTO NORTHWEST LOWER
WITH PERSISTENT MOIST UPSLOPE FLOW WITHIN WEST TO NORTHWEST WINDS.
SUPPOSE SOME LIGHT ACCUMULATIONS ARE POSSIBLE IN THIS AREA...BUT
DEFINITELY NOT ENOUGH TO WARRANT ANY MENTION IN OUR HAZARDOUS
WEATHER PRODUCTS.

&&

.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 237 AM EDT SUN APR 19 2015

REALLY NOT A WHOLE LOT OF
CHANGE EXPECTED TO START THIS PERIOD...WITH DIURNAL ENHANCEMENT AND
PASSING WAVES SUPPORTING MORE RAIN/SNOW SHOWERS RIGHT THROUGH
THURSDAY. REALLY HATE TO SAY THIS...BUT EVEN HINTS OVERHEAD AIR MAY
BE JUST COLD ENOUGH TO SUPPORT SOME MARGINAL LAKE ENHANCEMENT...
ESPECIALLY NOW WITH MOSTLY ICE-FREE CONDITIONS. SHOULDN`T BE TOO BIG
A DEAL IF THIS DOES OCCUR...AND PER LATE SPRING USUAL..."MOST" WOULD
OCCUR WEDNESDAY NIGHT WHEN DIURNAL DISRUPTION IS MINIMIZED.

WHILE DETAILS ARE ELUDING WITH RESPECT TO JUST HOW FAST SYSTEM
PUSHES OFF TO THE EAST...CANNOT FIND A COMPELLING REASON TO DEVIATE
FROM INHERITED DRY FORECAST THURSDAY NIGHT RIGHT THROUGH SATURDAY.
DEFINITELY PLAUSIBLE TROUGHING WILL REMAIN CLOSE ENOUGH TO ALLOW
ADDITIONAL WAVES/ATTENDANT SHOWERS TO PASS OVERHEAD. STILL HAVE
PLENTY OF TIME TO WATCH HOW THIS ALL UNFOLDS. EITHER WAY...COOL
CONDITIONS WILL NOT BE SO EASILY SCOURED OUT...WITH BELOW NORMAL
TEMPERATURES CONTINUING INTO THE START OF THE WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 142 PM EDT SUN APR 19 2015

MOISTURE HAS BEEN SLOW TO MOVE INTO THE REGION THIS AFTERNOON, AND
THUS, HAVE BEEN SLOWING DOWN THE TIMING OF THE RAIN. BEST GUESS AT
THIS POINT IN THE AFTERNOON, IS THAT IT SHOWS UP AROUND 23Z AT
MBL/TVC AREA, AND ABOUT 00Z AT APN/PLN. AFTER THAT THE VSBY LOOKS
TO FALL INTO THE MVFR CATEGORY, BUT THE CIGS BY 12Z/MON FALL TO
IFR AS THE LOW MOVES OVER US AND BRINGS MORE MOISTURE OVER THE
REGION.

&&

.MARINE...
ISSUED AT 237 AM EDT SUN APR 19 2015

LOW PRESSURE WILL LIFT NE INTO MICHIGAN TONIGHT...PRODUCING
WIDESPREAD RAIN ACROSS OUR ENTIRE NEARSHORE AREA. STRENGTHENING
EAST/SOUTHEAST WINDS AHEAD OF THAT SYSTEM TODAY AND TONIGHT WILL
LEAD TO SCA CONDITIONS FOR MUCH OF OUR NEARSHORE AREA...WITH WIND
GUSTS OF 15 TO 25 KTS EXPECTED. THE EXCEPTION WILL BE THE LAKE
MICHIGAN SHORELINE FROM MANISTEE TO THE BRIDGE...WHICH SHOULD FALL
JUST SHORT OF SCA CRITERIA.


&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LMZ341-342.

LS...SMALL CRAFT ADVISORY UNTIL 9 AM EDT MONDAY FOR LSZ321-322.

&&

$$

UPDATE...JSL
NEAR TERM...MLR
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...JSL
MARINE...MLR




000
FXUS63 KAPX 191748
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
148 PM EDT SUN APR 19 2015

.UPDATE...
ISSUED AT 1249 PM EDT SUN APR 19 2015

LOOKS LIKE THE MOISTURE IS SLOW INTO MOVING INTO THE REGION. SO
HAVE SLOWED DOWN THE PROGRESSION OF THE RAIN CONSIDERABLY. THE
CHANCE OF RAIN AREA IS NOW JUST GETTING TO M-55 BY 21Z INSTEAD OF
UP M-32. THIS IS BASED BOTH BY THE CURRENT OBS AND THE LATEST
GFS/NAM WITH THE RAP13 EVEN SLOWER. ALL OF THE MODELS AGREE THAT
THE RAIN SHOULD BE INTO E UPPER BY 06Z. SO WILL HOLD ONTO THAT
IDEA FOR NOW.

UPDATE ISSUED AT 952 AM EDT SUN APR 19 2015

HUDSON BAY HIGH IS SLOWLY MOVING EAST AND ALLOWING THE DEVELOPING
LOW PRESSURE SYSTEM IN THE CENTRAL PLAINS TO SLIDE INTO THE UPPER
GREAT LAKES. THE MAIN CONCERN FOR THE AFTERNOON, IS THE TIMING OF
THE RAIN START OR IF THE DRY AIR WILL CONTINUE A LITTLE LONGER.
BESIDES SLOWING THE RAIN START, THE DRY AIR COULD ALSO CAUSE AN
EXTENDED FIRE WEATHER CONCERN. HOWEVER, WITH THE CLOUDS
INCREASING, AND THE MOISTURE EXPECTED TO INCREASE WILL CONTINUE
WITH THE GOING FORECAST. WILL PROBABLY UPDATE THIS DISCUSSION
AROUND 1PM TO TALK ABOUT TIMING THEN AS WELL.

&&

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 237 AM EDT SUN APR 19 2015

STRONG HIGH PRESSURE CENTERED NE OF MICHIGAN REMAINS FIRMLY IN
CONTROL OF OUR WEATHER EARLY THIS MORNING...WITH MAINLY CLEAR SKIES
STILL OVERHEAD. HIGH CLOUD SHIELD ALONG THE NRN FRINGE OF INCREASING
MOISTURE HAS REACHED SRN LWR MICHIGAN...WELL NORTH OF DEVELOPING LOW
PRESSURE OVER THE MID MISSISSIPPI VALLEY. THIS LOW WILL GRADUALLY
DEEPEN AS IT LIFTS NE INTO LWR MICHIGAN TONIGHT...REACHING SAGINAW
BAY AND NE LWR MICHIGAN BY 12Z MONDAY. WIDESPREAD RAIN WILL DEVELOP
FROM SOUTH TO NORTH BEGINNING LATE AFTERNOON/EARLY EVENING...WITH
WIDESPREAD RAIN THEN CONTINUING FOR THE REMAINDER OF THE NIGHT AS
DEEP MOISTURE AND STRONG 700-500 MB LEVEL OMEGA LIFT INTO THE AREA
ALONG AND AHEAD OF THE SURFACE LOW CENTER.

IN THE MEANTIME...THE ONLY REAL CONCERN FOR TODAY IS THE POTENTIAL
FOR ONE MORE DAY OF ELEVATED FIRE DANGER GIVEN RECENT PERSISTE