Home > Products > Valid Products > AFD

000
FXUS63 KDTX 291637
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1237 PM EDT SUN MAR 29 2015

.UPDATE...

THE LINE OF PRECIPITATION OUT OVER LAKE MICHIGAN IS SLOWLY MAKING
ITS WAY EAST THIS AFTERNOON. THE AWIPS TIME OF ARRIVAL TOOL BRINGS
THE LINE OVER THE WESTERN CWA BETWEEN 19-20Z...OR 3-4 PM...QUICKLY
SPREADING ACROSS THE REST OF THE AREA TO THE EASTERN CWA BY 22Z OR
6 PM. GIVEN THE LATEST TRENDS WILL ADJUST THE POP GRIDS TO REFLECT
THE EARLIER TIME OF ARRIVAL.

DESPITE RELATIVELY WARM AFTERNOON TEMPERATURES AROUND 40 DEGREES
THERE IS A VERY DRY AIRMASS IN PLACE AS DEW POINTS RANGE FROM THE
MIDDLE TO UPPER TEENS. THIS SHOULD LEAD TO SOME WET BULBING AS
UPSTREAM OBSERVATIONS HAVE SHOWN A WIDE VARIETY OF PRECIPITATION
TYPES. WITH THE MAIN TYPES BEING RAIN OR SNOW WILL LEAVE THE
CURRENT FORECAST AS IS. REGARDING POPS THE LINE LOOKS SOLID SO 100
POPS ARE STILL APPROPRIATE GIVEN UPSTREAM OBSERVATIONS.

&&

.AVIATION...ISSUED 710 AM EDT SUN MAR 29 2015

A DRY ATMOSPHERE WILL BE IN PLACE THROUGHOUT THE MORNING AND EARLY
AFTERNOON HOURS AHEAD OF AN APPROACHING TROUGH. GROWTH OF THE
BOUNDARY LAYER WILL ALLOW SOUTHWESTERLY SURFACE WINDS TO BECOME
GUSTY WITH WIND SPEEDS LIKELY PUSHING NEAR 30 KNOTS.
PRECIPITATION IS EXPECTED TO ARRIVE SOMETIME AROUND 21Z AT ALL OF
THE TAF SITES AS A LOW LEVEL JET AXIS RAPIDLY LIFTS MOISTURE INTO
THE REGION. STILL SOME QUESTION ON PRECIPITATION TYPE...BUT
STRENGTH OF WARM AIR ADVECTION AND DAYTIME TEMPERATURES SHOULD
SUPPORT MORE LIQUID HYDROMETEOR TYPE. INCLUDED A -SHRASN MENTION
FOR PTK NORTHWARD...BUT NO ACCUMULATION IS EXPECTED. SYSTEM MOTION
IS EXPECTED TO BE VERY FAST WHICH WILL LEAD TO A SHORT
PRECIPITATION DURATION. LOSS OF MIDLEVEL MOISTURE THEN SUGGESTS A
3 TO 6 HOUR WINDOW FOR DRIZZLE AND BR DURING THE MID TO LATE
EVENING.

FOR DTW...VFR UNTIL 22Z-23Z WHEN MVFR CIGS WITH -SHRA WILL BECOME
INCREASINGLY LIKELY. WENT DECIDEDLY MORE PESSIMISTIC WITH CIGS
AFTER 00Z WITH NOCTURNAL COOLING CONTRIBUTIONS LIKELY LOWERING
CIGS INTO IFR. LACK OF MOISTURE DEPTH THEN BRINGS CONCERN FOR -DZ
FOR THE EVENING. SOUTHERLY WINDS FROM 190 TO 200 DEGREES WILL ALSO
GUST TO 25 KNOTS OR BETTER AT TIMES AFTER 18Z SUNDAY.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS AOB 5000 FEET AFTER 22Z-23Z TODAY.

* MEDIUM IN WIND GUSTS TO 25 KNOTS FROM 190-200 DEGREES BY 18Z-20Z
  SUNDAY.

&&

.PREV DISCUSSION...ISSUED 414 AM EDT SUN MAR 29 2015

SHORT TERM...TODAY AND TONIGHT

PRECIPITATION ACTIVITY PUSHING ACROSS THE NORTHERN PLAINS THIS
MORNING IS BEING FORCED BY STRONG WARM AIR ADVECTION AHEAD OF THE
VIGOROUS SHORTWAVE OVER WESTERN NODAK/SODAK. THE MAGNITUDE OF
MOISTURE TRANSPORT ON THE NOSE OF A +70 KNOT LOW LEVEL JET WHILE NOT
SURPRISING...IS NOTEWORTHY FOR TIME OF YEAR WITH PWATS OF UP TO .8
OF AN INCH. NWP DATA MAINTAINS THE STRENGTH OF THIS LLJ AXIS DURING
THE DAYLIGHT HOURS TODAY AND FORECASTS THE ARRIVAL OVER LOWER
MICHIGAN DURING THE AFTERNOON HOURS. THE TIME WINDOW FOR
PRECIPITATION ACROSS SEMICH IS BETWEEN 20-03Z.

12-21Z...IMPRESSIVE DEPTH OF INFLECTION POINT IN FLOW/TROUGH IN
ADDITION TO THE RELATIVELY CLOSE PROXIMITY YET OF THE SE US
ANTICYCLONE WILL ALLOW FOR A STRONG SURFACE PRESSURE GRADIENT BY
THIS AFTERNOON. SHORTWAVE RIDGE AXIS WILL TAKE UNTIL 15Z OR SO TO
PUSH COMPLETELY THROUGH THE CENTRAL GREAT LAKES. SUSPECT IT WILL
TAKE A GROWING BOUNDARY LAYER AND THIS ADDITIONAL SOUTHWESTERLY
GEOSTROPHIC FLOW COMPONENT AT THE MIDLEVELS TO GET GUSTY
SOUTHWESTERLY FLOW TO REALLY INCREASE AT THE SURFACE. SOUTHWESTERLY
WINDS THIS AFTERNOON ARE EXPECTED TO GUST 30 TO 35 MPH. TEMPERATURES
TODAY ARE EXPECTED TO RISE INTO THE LOWER 40S...HIGHEST IN THE
SAGINAW VALLEY/NORTH OF THE GLACIAL TERRAIN.

21-05Z...THE NARRATIVE OF HIGHER CONFIDENCE FOR PRECIPITATION AMOUNTS
REMAINS SOLID (.1 TO .15 OF INCH). ALSO OF HIGHER CONFIDENCE AND
NOTED EARLIER IS THIS EVENT WILL BE GOVERNED BY A VERY FAST SYSTEM
MOTION. THE FAST MOTION WILL NOT ONLY CAUSE A SHORT DURATION OF
PRECIPITATION OVERHEAD...BUT IS ALSO SHOWN TO BE A DETRIMENT TO
CHARACTER/STRENGTH OF THE WARM AIR ADVECTION BY THINNING THE THETA
E RIDGE FOR WHICH THE SYSTEM CAN ACT UPON.

THE MAIN FORECAST QUESTION REMAINS CENTERED ON PRECIPITATION TYPE.
THE 29.00Z MODEL SUITE DID NOT OFFER A WHOLE LOT OF CLARITY ON THIS
SUBJECT...PROBABLY BEST SUMMED UP BY THE HUGE DIFFERENCE THAT
REMAINS IN FORECASTED AFTERNOON SURFACE DEWPOINTS PER MET/MAV. THERE
IS A STRONG MODEL CONSENSUS FOR WETBULB COOLING AT PRECIPITATION
ONSET. IN FACT...RAW MODEL OUTPUT SHOWS SURFACE TEMPERATURES WARMING
MARGINALLY DURING THE MID TO LATE EVENING AFTER PRECIPITATION RATES
DECREASE. CONSENSUS ON MODEL SOUNDINGS IS THAT OF A COLD
PROFILE...WITH LITTLE TO NO WARM SURGE ALOFT. SO...THIS SUGGESTS
PTYPE WILL BE LARGELY DICTATED BY THE DEPTH AND MAGNITUDE OF
SURFACE WARMING TODAY. WITH TEMPS EXPECTED TO REACH THE
40S...SUSPICION AND GUT FEELING IS THE AREA WILL SEE MUCH MORE
LIQUID. HOWEVER...GIVEN THE THERMAL PROFILE AND THE COLD SFC
DEWPOINTS CANNOT RULE OUT SNOW MIXING IN. NOT MUCH OF A CONCERN
WITH LITTLE TO NO ACCUMULATION EXPECTED. THIN NATURE OF THETA E
RIDGE THEN SUPPORTS MOISTURE STRIPPING OUT IN THE MIDLEVELS
ALREADY BY 00Z. THUS...CAN VERY WELL ENVISION A SCENARIO WHERE ICE
NUCLEATION BECOMES A PROBLEM AND SEE A MARKED TRANSITION TO
DRIZZLE DURING THE EVENING.

05-12Z...SECONDARY COLD FRONT STRUCTURE SHOWN TO PUSH THROUGH THE
STATE BETWEEN 05-06Z. THE PASSAGE OF THIS FEATURE SHOULD THEN
DECREASE THE POTENTIAL FOR DRIZZLE DURING THE LATTER HALF OF THE
NIGHT DUE TO DRY AIR ADVECTION. SURFACE TEMPERATURES REMAINING ON
THE WARM SIDE OF THE FREEZING MARK WILL LIMIT THE POTENTIAL
FOR RESIDUAL MOISTURE TO FREEZE.

LONG TERM...

WEAK COLD ADVECTION TRAILING TODAY`S SYSTEM WILL BECOME NEUTRAL
DURING MONDAY MORNING. MODEL SOUNDINGS INDICATE A DEEP BOUNDARY
LAYER GROWING TO NEAR 800 MB BY MID AFTERNOON RESULTING IN NORTHWEST
WIND GUSTING TO AROUND 25 MPH BEFORE THE SURFACE RIDGE ARRIVES LATE
IN THE DAY. THIS...ALONG WITH INCREASING AMOUNTS OF SUNSHINE...WILL
HELP AFTERNOON TEMPS END UP WARMER THAN TODAY WITH HIGHS IN THE MID
TO UPPER 40S OUTSIDE OF THE NORTHERN THUMB.

THE MAIN REASON FOR THE ABBREVIATED COLD ADVECTION MONDAY IS THE
QUICK APPROACH OF THE NEXT RIPPLE OF LOW PRESSURE THROUGH THE PLAINS
AND INTO THE MIDWEST BY MONDAY EVENING. THIS SYSTEM IS DEPICTED IN
THE MODEL DATA AS A SHARD OF UPPER LEVEL ENERGY FROM THE LOW OVER
THE GULF OF ALASKA ROUNDING THE LONG WAVE RIDGE TODAY AND MOVING
THROUGH THE CANADIAN PRAIRIE MONDAY. THE SYSTEM THEN QUICKLY LATCHES
ON TO LOW LEVEL BAROCLINICITY OVER THE NORTHERN PLAINS THAT IS LEFT
OVER FROM TODAY`S SYSTEM. REMNANTS OF THE SURFACE FRONT WILL BE TO
OUR SOUTH BUT THE MID LEVELS OF THE FRONTAL ZONE WILL REMAIN WELL
ORGANIZED OVERHEAD AND TO OUR WEST THROUGH MONDAY. CONSIDERING THE
FAST NORTHWEST FLOW ALOFT...THE WAVE WILL FAVOR A TRACK ALONG THE
700 MB THETA-E GRADIENT. MODEL SOLUTIONS WITH A LOWER AMPLITUDE MID
LEVEL WAVE AND STRONGER FRONTOGENESIS LOOK BEST WHICH LEAVES THE NAM
AS AN OVERDEVELOPED OUTLIER. THE WILDCARD HERE IS THAT THE LOW LEVEL
MOISTURE BROUGHT IN BY TODAY`S SYSTEM IS NEVER REALLY SCOURED OUT
MONDAY AND REMAINS READILY AVAILABLE AT ABOUT 3 G/KG FOR THE SYSTEM
MONDAY NIGHT INTO TUESDAY. THIS EASILY SUPPORTS MODEL QPF IN THE
RANGE OF 0.25 TO 0.5 INCH BUT STILL PUTS THE NAM UNDER SUSPICION FOR
BEING OVERDEVELOPED WITH ITS SURFACE LOW FOLLOWING ITS 850-500 MB
LAYER OMEGA BULLSEYE. LEANING THE FORECAST TOWARD A MORE LIKELY
TRACK FARTHER SOUTH THEN PRESENTS PRIMARILY A RAIN EVENT FOR THE
DETROIT AREA...A RAIN/SNOW MIX FOR THE M-59 TO I-69 CORRIDOR...AND
THEN MOSTLY SNOW FOR THE SAGINAW VALLEY AND NORTHERN THUMB. SINGLE
DIGIT SNOW RATIO WILL BE A LIMITING FACTOR EVEN THAT FAR NORTH...SO
ACCUMULATION WILL BE SET AT A SLOPPY 1-2 INCHES AS A STARTING
POINT.

THE SECOND HALF OF THE WEEK WILL CONSIST OF A TRANSITION IN THE LONG
WAVE PATTERN FROM THE PERSISTENT RIDGE OUT WEST/TROUGH EAST TO MORE
OF ZONAL CONFIGURATION. THIS WILL BE SET OFF BY THE CURRENT GULF OF
ALASKA LOW MOVING INLAND AND REACHING THE NORTHERN PLAINS WEDNESDAY
INTO THURSDAY. THE LARGE SURFACE LOW PRESSURE PATTERN WILL GENERATE
DEEP SOUTHWEST FLOW EAST OF THE MISSISSIPPI AND A WARMING TREND FOR
LOWER MICHIGAN. GUIDANCE TEMPS LOOK GOOD CALLING FOR HIGHS IN THE
60S THURSDAY BEFORE THE COLD FRONT ARRIVES THURSDAY NIGHT INTO
FRIDAY. THIS FRONT WILL BRING TEMPERATURES BACK BELOW NORMAL HEADING
INTO NEXT WEEKEND.

MARINE...

A GALE WARNING IS IN EFFECT FOR SAGINAW BAY AND CENTRAL LAKE HURON
TODAY AND TONIGHT...AND THROUGH MONDAY AFTERNOON FOR THE NORTH THIRD
OF LAKE HURON. SOUTHWEST GALES WILL DEVELOP AS A LOW PRESSURE SYSTEM
MOVES THROUGH THE NORTHERN GREAT LAKES TODAY. THIS WILL BE FOLLOWED
BY NORTHWEST GALES BEHIND THE ASSOCIATED COLD FRONT OVERNIGHT
THROUGH MONDAY AFTERNOON. THE PRESENCE OF A MODEST AMOUNT OF COLD
AIR IN ADVANCE OF THE LOW...SOME OPEN WATER ON LAKE HURON...AND
FUNNELING IN SAGINAW BAY WILL SUPPORT GALE CONDITIONS. THE SECOND
ROUND OF GALES WILL BE FROM THE NORTHWEST AND WILL BEGIN DURING THE
PREDAWN HOURS MONDAY AND PERSIST THROUGH MIDDAY. TRANQUIL CONDITIONS
WILL TAKE HOLD BENEATH HIGH PRESSURE ON MONDAY NIGHT. THE NEXT LOW
PRESSURE SYSTEM IS DUE IN THE AREA LATE MONDAY NIGHT INTO TUESDAY
BUT WIND SPEED WILL BE LOWER WITH THIS SYSTEM.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WARNING UNTIL MIDNIGHT EDT TONIGHT FOR LHZ363-421-422-441-462.

     SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ442-443.

     GALE WARNING UNTIL 6 PM EDT MONDAY FOR LHZ361-362.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

UPDATE.......KURIMSKI
AVIATION.....CB
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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




000
FXUS63 KDTX 291637
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1237 PM EDT SUN MAR 29 2015

.UPDATE...

THE LINE OF PRECIPITATION OUT OVER LAKE MICHIGAN IS SLOWLY MAKING
ITS WAY EAST THIS AFTERNOON. THE AWIPS TIME OF ARRIVAL TOOL BRINGS
THE LINE OVER THE WESTERN CWA BETWEEN 19-20Z...OR 3-4 PM...QUICKLY
SPREADING ACROSS THE REST OF THE AREA TO THE EASTERN CWA BY 22Z OR
6 PM. GIVEN THE LATEST TRENDS WILL ADJUST THE POP GRIDS TO REFLECT
THE EARLIER TIME OF ARRIVAL.

DESPITE RELATIVELY WARM AFTERNOON TEMPERATURES AROUND 40 DEGREES
THERE IS A VERY DRY AIRMASS IN PLACE AS DEW POINTS RANGE FROM THE
MIDDLE TO UPPER TEENS. THIS SHOULD LEAD TO SOME WET BULBING AS
UPSTREAM OBSERVATIONS HAVE SHOWN A WIDE VARIETY OF PRECIPITATION
TYPES. WITH THE MAIN TYPES BEING RAIN OR SNOW WILL LEAVE THE
CURRENT FORECAST AS IS. REGARDING POPS THE LINE LOOKS SOLID SO 100
POPS ARE STILL APPROPRIATE GIVEN UPSTREAM OBSERVATIONS.

&&

.AVIATION...ISSUED 710 AM EDT SUN MAR 29 2015

A DRY ATMOSPHERE WILL BE IN PLACE THROUGHOUT THE MORNING AND EARLY
AFTERNOON HOURS AHEAD OF AN APPROACHING TROUGH. GROWTH OF THE
BOUNDARY LAYER WILL ALLOW SOUTHWESTERLY SURFACE WINDS TO BECOME
GUSTY WITH WIND SPEEDS LIKELY PUSHING NEAR 30 KNOTS.
PRECIPITATION IS EXPECTED TO ARRIVE SOMETIME AROUND 21Z AT ALL OF
THE TAF SITES AS A LOW LEVEL JET AXIS RAPIDLY LIFTS MOISTURE INTO
THE REGION. STILL SOME QUESTION ON PRECIPITATION TYPE...BUT
STRENGTH OF WARM AIR ADVECTION AND DAYTIME TEMPERATURES SHOULD
SUPPORT MORE LIQUID HYDROMETEOR TYPE. INCLUDED A -SHRASN MENTION
FOR PTK NORTHWARD...BUT NO ACCUMULATION IS EXPECTED. SYSTEM MOTION
IS EXPECTED TO BE VERY FAST WHICH WILL LEAD TO A SHORT
PRECIPITATION DURATION. LOSS OF MIDLEVEL MOISTURE THEN SUGGESTS A
3 TO 6 HOUR WINDOW FOR DRIZZLE AND BR DURING THE MID TO LATE
EVENING.

FOR DTW...VFR UNTIL 22Z-23Z WHEN MVFR CIGS WITH -SHRA WILL BECOME
INCREASINGLY LIKELY. WENT DECIDEDLY MORE PESSIMISTIC WITH CIGS
AFTER 00Z WITH NOCTURNAL COOLING CONTRIBUTIONS LIKELY LOWERING
CIGS INTO IFR. LACK OF MOISTURE DEPTH THEN BRINGS CONCERN FOR -DZ
FOR THE EVENING. SOUTHERLY WINDS FROM 190 TO 200 DEGREES WILL ALSO
GUST TO 25 KNOTS OR BETTER AT TIMES AFTER 18Z SUNDAY.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS AOB 5000 FEET AFTER 22Z-23Z TODAY.

* MEDIUM IN WIND GUSTS TO 25 KNOTS FROM 190-200 DEGREES BY 18Z-20Z
  SUNDAY.

&&

.PREV DISCUSSION...ISSUED 414 AM EDT SUN MAR 29 2015

SHORT TERM...TODAY AND TONIGHT

PRECIPITATION ACTIVITY PUSHING ACROSS THE NORTHERN PLAINS THIS
MORNING IS BEING FORCED BY STRONG WARM AIR ADVECTION AHEAD OF THE
VIGOROUS SHORTWAVE OVER WESTERN NODAK/SODAK. THE MAGNITUDE OF
MOISTURE TRANSPORT ON THE NOSE OF A +70 KNOT LOW LEVEL JET WHILE NOT
SURPRISING...IS NOTEWORTHY FOR TIME OF YEAR WITH PWATS OF UP TO .8
OF AN INCH. NWP DATA MAINTAINS THE STRENGTH OF THIS LLJ AXIS DURING
THE DAYLIGHT HOURS TODAY AND FORECASTS THE ARRIVAL OVER LOWER
MICHIGAN DURING THE AFTERNOON HOURS. THE TIME WINDOW FOR
PRECIPITATION ACROSS SEMICH IS BETWEEN 20-03Z.

12-21Z...IMPRESSIVE DEPTH OF INFLECTION POINT IN FLOW/TROUGH IN
ADDITION TO THE RELATIVELY CLOSE PROXIMITY YET OF THE SE US
ANTICYCLONE WILL ALLOW FOR A STRONG SURFACE PRESSURE GRADIENT BY
THIS AFTERNOON. SHORTWAVE RIDGE AXIS WILL TAKE UNTIL 15Z OR SO TO
PUSH COMPLETELY THROUGH THE CENTRAL GREAT LAKES. SUSPECT IT WILL
TAKE A GROWING BOUNDARY LAYER AND THIS ADDITIONAL SOUTHWESTERLY
GEOSTROPHIC FLOW COMPONENT AT THE MIDLEVELS TO GET GUSTY
SOUTHWESTERLY FLOW TO REALLY INCREASE AT THE SURFACE. SOUTHWESTERLY
WINDS THIS AFTERNOON ARE EXPECTED TO GUST 30 TO 35 MPH. TEMPERATURES
TODAY ARE EXPECTED TO RISE INTO THE LOWER 40S...HIGHEST IN THE
SAGINAW VALLEY/NORTH OF THE GLACIAL TERRAIN.

21-05Z...THE NARRATIVE OF HIGHER CONFIDENCE FOR PRECIPITATION AMOUNTS
REMAINS SOLID (.1 TO .15 OF INCH). ALSO OF HIGHER CONFIDENCE AND
NOTED EARLIER IS THIS EVENT WILL BE GOVERNED BY A VERY FAST SYSTEM
MOTION. THE FAST MOTION WILL NOT ONLY CAUSE A SHORT DURATION OF
PRECIPITATION OVERHEAD...BUT IS ALSO SHOWN TO BE A DETRIMENT TO
CHARACTER/STRENGTH OF THE WARM AIR ADVECTION BY THINNING THE THETA
E RIDGE FOR WHICH THE SYSTEM CAN ACT UPON.

THE MAIN FORECAST QUESTION REMAINS CENTERED ON PRECIPITATION TYPE.
THE 29.00Z MODEL SUITE DID NOT OFFER A WHOLE LOT OF CLARITY ON THIS
SUBJECT...PROBABLY BEST SUMMED UP BY THE HUGE DIFFERENCE THAT
REMAINS IN FORECASTED AFTERNOON SURFACE DEWPOINTS PER MET/MAV. THERE
IS A STRONG MODEL CONSENSUS FOR WETBULB COOLING AT PRECIPITATION
ONSET. IN FACT...RAW MODEL OUTPUT SHOWS SURFACE TEMPERATURES WARMING
MARGINALLY DURING THE MID TO LATE EVENING AFTER PRECIPITATION RATES
DECREASE. CONSENSUS ON MODEL SOUNDINGS IS THAT OF A COLD
PROFILE...WITH LITTLE TO NO WARM SURGE ALOFT. SO...THIS SUGGESTS
PTYPE WILL BE LARGELY DICTATED BY THE DEPTH AND MAGNITUDE OF
SURFACE WARMING TODAY. WITH TEMPS EXPECTED TO REACH THE
40S...SUSPICION AND GUT FEELING IS THE AREA WILL SEE MUCH MORE
LIQUID. HOWEVER...GIVEN THE THERMAL PROFILE AND THE COLD SFC
DEWPOINTS CANNOT RULE OUT SNOW MIXING IN. NOT MUCH OF A CONCERN
WITH LITTLE TO NO ACCUMULATION EXPECTED. THIN NATURE OF THETA E
RIDGE THEN SUPPORTS MOISTURE STRIPPING OUT IN THE MIDLEVELS
ALREADY BY 00Z. THUS...CAN VERY WELL ENVISION A SCENARIO WHERE ICE
NUCLEATION BECOMES A PROBLEM AND SEE A MARKED TRANSITION TO
DRIZZLE DURING THE EVENING.

05-12Z...SECONDARY COLD FRONT STRUCTURE SHOWN TO PUSH THROUGH THE
STATE BETWEEN 05-06Z. THE PASSAGE OF THIS FEATURE SHOULD THEN
DECREASE THE POTENTIAL FOR DRIZZLE DURING THE LATTER HALF OF THE
NIGHT DUE TO DRY AIR ADVECTION. SURFACE TEMPERATURES REMAINING ON
THE WARM SIDE OF THE FREEZING MARK WILL LIMIT THE POTENTIAL
FOR RESIDUAL MOISTURE TO FREEZE.

LONG TERM...

WEAK COLD ADVECTION TRAILING TODAY`S SYSTEM WILL BECOME NEUTRAL
DURING MONDAY MORNING. MODEL SOUNDINGS INDICATE A DEEP BOUNDARY
LAYER GROWING TO NEAR 800 MB BY MID AFTERNOON RESULTING IN NORTHWEST
WIND GUSTING TO AROUND 25 MPH BEFORE THE SURFACE RIDGE ARRIVES LATE
IN THE DAY. THIS...ALONG WITH INCREASING AMOUNTS OF SUNSHINE...WILL
HELP AFTERNOON TEMPS END UP WARMER THAN TODAY WITH HIGHS IN THE MID
TO UPPER 40S OUTSIDE OF THE NORTHERN THUMB.

THE MAIN REASON FOR THE ABBREVIATED COLD ADVECTION MONDAY IS THE
QUICK APPROACH OF THE NEXT RIPPLE OF LOW PRESSURE THROUGH THE PLAINS
AND INTO THE MIDWEST BY MONDAY EVENING. THIS SYSTEM IS DEPICTED IN
THE MODEL DATA AS A SHARD OF UPPER LEVEL ENERGY FROM THE LOW OVER
THE GULF OF ALASKA ROUNDING THE LONG WAVE RIDGE TODAY AND MOVING
THROUGH THE CANADIAN PRAIRIE MONDAY. THE SYSTEM THEN QUICKLY LATCHES
ON TO LOW LEVEL BAROCLINICITY OVER THE NORTHERN PLAINS THAT IS LEFT
OVER FROM TODAY`S SYSTEM. REMNANTS OF THE SURFACE FRONT WILL BE TO
OUR SOUTH BUT THE MID LEVELS OF THE FRONTAL ZONE WILL REMAIN WELL
ORGANIZED OVERHEAD AND TO OUR WEST THROUGH MONDAY. CONSIDERING THE
FAST NORTHWEST FLOW ALOFT...THE WAVE WILL FAVOR A TRACK ALONG THE
700 MB THETA-E GRADIENT. MODEL SOLUTIONS WITH A LOWER AMPLITUDE MID
LEVEL WAVE AND STRONGER FRONTOGENESIS LOOK BEST WHICH LEAVES THE NAM
AS AN OVERDEVELOPED OUTLIER. THE WILDCARD HERE IS THAT THE LOW LEVEL
MOISTURE BROUGHT IN BY TODAY`S SYSTEM IS NEVER REALLY SCOURED OUT
MONDAY AND REMAINS READILY AVAILABLE AT ABOUT 3 G/KG FOR THE SYSTEM
MONDAY NIGHT INTO TUESDAY. THIS EASILY SUPPORTS MODEL QPF IN THE
RANGE OF 0.25 TO 0.5 INCH BUT STILL PUTS THE NAM UNDER SUSPICION FOR
BEING OVERDEVELOPED WITH ITS SURFACE LOW FOLLOWING ITS 850-500 MB
LAYER OMEGA BULLSEYE. LEANING THE FORECAST TOWARD A MORE LIKELY
TRACK FARTHER SOUTH THEN PRESENTS PRIMARILY A RAIN EVENT FOR THE
DETROIT AREA...A RAIN/SNOW MIX FOR THE M-59 TO I-69 CORRIDOR...AND
THEN MOSTLY SNOW FOR THE SAGINAW VALLEY AND NORTHERN THUMB. SINGLE
DIGIT SNOW RATIO WILL BE A LIMITING FACTOR EVEN THAT FAR NORTH...SO
ACCUMULATION WILL BE SET AT A SLOPPY 1-2 INCHES AS A STARTING
POINT.

THE SECOND HALF OF THE WEEK WILL CONSIST OF A TRANSITION IN THE LONG
WAVE PATTERN FROM THE PERSISTENT RIDGE OUT WEST/TROUGH EAST TO MORE
OF ZONAL CONFIGURATION. THIS WILL BE SET OFF BY THE CURRENT GULF OF
ALASKA LOW MOVING INLAND AND REACHING THE NORTHERN PLAINS WEDNESDAY
INTO THURSDAY. THE LARGE SURFACE LOW PRESSURE PATTERN WILL GENERATE
DEEP SOUTHWEST FLOW EAST OF THE MISSISSIPPI AND A WARMING TREND FOR
LOWER MICHIGAN. GUIDANCE TEMPS LOOK GOOD CALLING FOR HIGHS IN THE
60S THURSDAY BEFORE THE COLD FRONT ARRIVES THURSDAY NIGHT INTO
FRIDAY. THIS FRONT WILL BRING TEMPERATURES BACK BELOW NORMAL HEADING
INTO NEXT WEEKEND.

MARINE...

A GALE WARNING IS IN EFFECT FOR SAGINAW BAY AND CENTRAL LAKE HURON
TODAY AND TONIGHT...AND THROUGH MONDAY AFTERNOON FOR THE NORTH THIRD
OF LAKE HURON. SOUTHWEST GALES WILL DEVELOP AS A LOW PRESSURE SYSTEM
MOVES THROUGH THE NORTHERN GREAT LAKES TODAY. THIS WILL BE FOLLOWED
BY NORTHWEST GALES BEHIND THE ASSOCIATED COLD FRONT OVERNIGHT
THROUGH MONDAY AFTERNOON. THE PRESENCE OF A MODEST AMOUNT OF COLD
AIR IN ADVANCE OF THE LOW...SOME OPEN WATER ON LAKE HURON...AND
FUNNELING IN SAGINAW BAY WILL SUPPORT GALE CONDITIONS. THE SECOND
ROUND OF GALES WILL BE FROM THE NORTHWEST AND WILL BEGIN DURING THE
PREDAWN HOURS MONDAY AND PERSIST THROUGH MIDDAY. TRANQUIL CONDITIONS
WILL TAKE HOLD BENEATH HIGH PRESSURE ON MONDAY NIGHT. THE NEXT LOW
PRESSURE SYSTEM IS DUE IN THE AREA LATE MONDAY NIGHT INTO TUESDAY
BUT WIND SPEED WILL BE LOWER WITH THIS SYSTEM.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WARNING UNTIL MIDNIGHT EDT TONIGHT FOR LHZ363-421-422-441-462.

     SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ442-443.

     GALE WARNING UNTIL 6 PM EDT MONDAY FOR LHZ361-362.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

UPDATE.......KURIMSKI
AVIATION.....CB
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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





000
FXUS63 KDTX 291637
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1237 PM EDT SUN MAR 29 2015

.UPDATE...

THE LINE OF PRECIPITATION OUT OVER LAKE MICHIGAN IS SLOWLY MAKING
ITS WAY EAST THIS AFTERNOON. THE AWIPS TIME OF ARRIVAL TOOL BRINGS
THE LINE OVER THE WESTERN CWA BETWEEN 19-20Z...OR 3-4 PM...QUICKLY
SPREADING ACROSS THE REST OF THE AREA TO THE EASTERN CWA BY 22Z OR
6 PM. GIVEN THE LATEST TRENDS WILL ADJUST THE POP GRIDS TO REFLECT
THE EARLIER TIME OF ARRIVAL.

DESPITE RELATIVELY WARM AFTERNOON TEMPERATURES AROUND 40 DEGREES
THERE IS A VERY DRY AIRMASS IN PLACE AS DEW POINTS RANGE FROM THE
MIDDLE TO UPPER TEENS. THIS SHOULD LEAD TO SOME WET BULBING AS
UPSTREAM OBSERVATIONS HAVE SHOWN A WIDE VARIETY OF PRECIPITATION
TYPES. WITH THE MAIN TYPES BEING RAIN OR SNOW WILL LEAVE THE
CURRENT FORECAST AS IS. REGARDING POPS THE LINE LOOKS SOLID SO 100
POPS ARE STILL APPROPRIATE GIVEN UPSTREAM OBSERVATIONS.

&&

.AVIATION...ISSUED 710 AM EDT SUN MAR 29 2015

A DRY ATMOSPHERE WILL BE IN PLACE THROUGHOUT THE MORNING AND EARLY
AFTERNOON HOURS AHEAD OF AN APPROACHING TROUGH. GROWTH OF THE
BOUNDARY LAYER WILL ALLOW SOUTHWESTERLY SURFACE WINDS TO BECOME
GUSTY WITH WIND SPEEDS LIKELY PUSHING NEAR 30 KNOTS.
PRECIPITATION IS EXPECTED TO ARRIVE SOMETIME AROUND 21Z AT ALL OF
THE TAF SITES AS A LOW LEVEL JET AXIS RAPIDLY LIFTS MOISTURE INTO
THE REGION. STILL SOME QUESTION ON PRECIPITATION TYPE...BUT
STRENGTH OF WARM AIR ADVECTION AND DAYTIME TEMPERATURES SHOULD
SUPPORT MORE LIQUID HYDROMETEOR TYPE. INCLUDED A -SHRASN MENTION
FOR PTK NORTHWARD...BUT NO ACCUMULATION IS EXPECTED. SYSTEM MOTION
IS EXPECTED TO BE VERY FAST WHICH WILL LEAD TO A SHORT
PRECIPITATION DURATION. LOSS OF MIDLEVEL MOISTURE THEN SUGGESTS A
3 TO 6 HOUR WINDOW FOR DRIZZLE AND BR DURING THE MID TO LATE
EVENING.

FOR DTW...VFR UNTIL 22Z-23Z WHEN MVFR CIGS WITH -SHRA WILL BECOME
INCREASINGLY LIKELY. WENT DECIDEDLY MORE PESSIMISTIC WITH CIGS
AFTER 00Z WITH NOCTURNAL COOLING CONTRIBUTIONS LIKELY LOWERING
CIGS INTO IFR. LACK OF MOISTURE DEPTH THEN BRINGS CONCERN FOR -DZ
FOR THE EVENING. SOUTHERLY WINDS FROM 190 TO 200 DEGREES WILL ALSO
GUST TO 25 KNOTS OR BETTER AT TIMES AFTER 18Z SUNDAY.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS AOB 5000 FEET AFTER 22Z-23Z TODAY.

* MEDIUM IN WIND GUSTS TO 25 KNOTS FROM 190-200 DEGREES BY 18Z-20Z
  SUNDAY.

&&

.PREV DISCUSSION...ISSUED 414 AM EDT SUN MAR 29 2015

SHORT TERM...TODAY AND TONIGHT

PRECIPITATION ACTIVITY PUSHING ACROSS THE NORTHERN PLAINS THIS
MORNING IS BEING FORCED BY STRONG WARM AIR ADVECTION AHEAD OF THE
VIGOROUS SHORTWAVE OVER WESTERN NODAK/SODAK. THE MAGNITUDE OF
MOISTURE TRANSPORT ON THE NOSE OF A +70 KNOT LOW LEVEL JET WHILE NOT
SURPRISING...IS NOTEWORTHY FOR TIME OF YEAR WITH PWATS OF UP TO .8
OF AN INCH. NWP DATA MAINTAINS THE STRENGTH OF THIS LLJ AXIS DURING
THE DAYLIGHT HOURS TODAY AND FORECASTS THE ARRIVAL OVER LOWER
MICHIGAN DURING THE AFTERNOON HOURS. THE TIME WINDOW FOR
PRECIPITATION ACROSS SEMICH IS BETWEEN 20-03Z.

12-21Z...IMPRESSIVE DEPTH OF INFLECTION POINT IN FLOW/TROUGH IN
ADDITION TO THE RELATIVELY CLOSE PROXIMITY YET OF THE SE US
ANTICYCLONE WILL ALLOW FOR A STRONG SURFACE PRESSURE GRADIENT BY
THIS AFTERNOON. SHORTWAVE RIDGE AXIS WILL TAKE UNTIL 15Z OR SO TO
PUSH COMPLETELY THROUGH THE CENTRAL GREAT LAKES. SUSPECT IT WILL
TAKE A GROWING BOUNDARY LAYER AND THIS ADDITIONAL SOUTHWESTERLY
GEOSTROPHIC FLOW COMPONENT AT THE MIDLEVELS TO GET GUSTY
SOUTHWESTERLY FLOW TO REALLY INCREASE AT THE SURFACE. SOUTHWESTERLY
WINDS THIS AFTERNOON ARE EXPECTED TO GUST 30 TO 35 MPH. TEMPERATURES
TODAY ARE EXPECTED TO RISE INTO THE LOWER 40S...HIGHEST IN THE
SAGINAW VALLEY/NORTH OF THE GLACIAL TERRAIN.

21-05Z...THE NARRATIVE OF HIGHER CONFIDENCE FOR PRECIPITATION AMOUNTS
REMAINS SOLID (.1 TO .15 OF INCH). ALSO OF HIGHER CONFIDENCE AND
NOTED EARLIER IS THIS EVENT WILL BE GOVERNED BY A VERY FAST SYSTEM
MOTION. THE FAST MOTION WILL NOT ONLY CAUSE A SHORT DURATION OF
PRECIPITATION OVERHEAD...BUT IS ALSO SHOWN TO BE A DETRIMENT TO
CHARACTER/STRENGTH OF THE WARM AIR ADVECTION BY THINNING THE THETA
E RIDGE FOR WHICH THE SYSTEM CAN ACT UPON.

THE MAIN FORECAST QUESTION REMAINS CENTERED ON PRECIPITATION TYPE.
THE 29.00Z MODEL SUITE DID NOT OFFER A WHOLE LOT OF CLARITY ON THIS
SUBJECT...PROBABLY BEST SUMMED UP BY THE HUGE DIFFERENCE THAT
REMAINS IN FORECASTED AFTERNOON SURFACE DEWPOINTS PER MET/MAV. THERE
IS A STRONG MODEL CONSENSUS FOR WETBULB COOLING AT PRECIPITATION
ONSET. IN FACT...RAW MODEL OUTPUT SHOWS SURFACE TEMPERATURES WARMING
MARGINALLY DURING THE MID TO LATE EVENING AFTER PRECIPITATION RATES
DECREASE. CONSENSUS ON MODEL SOUNDINGS IS THAT OF A COLD
PROFILE...WITH LITTLE TO NO WARM SURGE ALOFT. SO...THIS SUGGESTS
PTYPE WILL BE LARGELY DICTATED BY THE DEPTH AND MAGNITUDE OF
SURFACE WARMING TODAY. WITH TEMPS EXPECTED TO REACH THE
40S...SUSPICION AND GUT FEELING IS THE AREA WILL SEE MUCH MORE
LIQUID. HOWEVER...GIVEN THE THERMAL PROFILE AND THE COLD SFC
DEWPOINTS CANNOT RULE OUT SNOW MIXING IN. NOT MUCH OF A CONCERN
WITH LITTLE TO NO ACCUMULATION EXPECTED. THIN NATURE OF THETA E
RIDGE THEN SUPPORTS MOISTURE STRIPPING OUT IN THE MIDLEVELS
ALREADY BY 00Z. THUS...CAN VERY WELL ENVISION A SCENARIO WHERE ICE
NUCLEATION BECOMES A PROBLEM AND SEE A MARKED TRANSITION TO
DRIZZLE DURING THE EVENING.

05-12Z...SECONDARY COLD FRONT STRUCTURE SHOWN TO PUSH THROUGH THE
STATE BETWEEN 05-06Z. THE PASSAGE OF THIS FEATURE SHOULD THEN
DECREASE THE POTENTIAL FOR DRIZZLE DURING THE LATTER HALF OF THE
NIGHT DUE TO DRY AIR ADVECTION. SURFACE TEMPERATURES REMAINING ON
THE WARM SIDE OF THE FREEZING MARK WILL LIMIT THE POTENTIAL
FOR RESIDUAL MOISTURE TO FREEZE.

LONG TERM...

WEAK COLD ADVECTION TRAILING TODAY`S SYSTEM WILL BECOME NEUTRAL
DURING MONDAY MORNING. MODEL SOUNDINGS INDICATE A DEEP BOUNDARY
LAYER GROWING TO NEAR 800 MB BY MID AFTERNOON RESULTING IN NORTHWEST
WIND GUSTING TO AROUND 25 MPH BEFORE THE SURFACE RIDGE ARRIVES LATE
IN THE DAY. THIS...ALONG WITH INCREASING AMOUNTS OF SUNSHINE...WILL
HELP AFTERNOON TEMPS END UP WARMER THAN TODAY WITH HIGHS IN THE MID
TO UPPER 40S OUTSIDE OF THE NORTHERN THUMB.

THE MAIN REASON FOR THE ABBREVIATED COLD ADVECTION MONDAY IS THE
QUICK APPROACH OF THE NEXT RIPPLE OF LOW PRESSURE THROUGH THE PLAINS
AND INTO THE MIDWEST BY MONDAY EVENING. THIS SYSTEM IS DEPICTED IN
THE MODEL DATA AS A SHARD OF UPPER LEVEL ENERGY FROM THE LOW OVER
THE GULF OF ALASKA ROUNDING THE LONG WAVE RIDGE TODAY AND MOVING
THROUGH THE CANADIAN PRAIRIE MONDAY. THE SYSTEM THEN QUICKLY LATCHES
ON TO LOW LEVEL BAROCLINICITY OVER THE NORTHERN PLAINS THAT IS LEFT
OVER FROM TODAY`S SYSTEM. REMNANTS OF THE SURFACE FRONT WILL BE TO
OUR SOUTH BUT THE MID LEVELS OF THE FRONTAL ZONE WILL REMAIN WELL
ORGANIZED OVERHEAD AND TO OUR WEST THROUGH MONDAY. CONSIDERING THE
FAST NORTHWEST FLOW ALOFT...THE WAVE WILL FAVOR A TRACK ALONG THE
700 MB THETA-E GRADIENT. MODEL SOLUTIONS WITH A LOWER AMPLITUDE MID
LEVEL WAVE AND STRONGER FRONTOGENESIS LOOK BEST WHICH LEAVES THE NAM
AS AN OVERDEVELOPED OUTLIER. THE WILDCARD HERE IS THAT THE LOW LEVEL
MOISTURE BROUGHT IN BY TODAY`S SYSTEM IS NEVER REALLY SCOURED OUT
MONDAY AND REMAINS READILY AVAILABLE AT ABOUT 3 G/KG FOR THE SYSTEM
MONDAY NIGHT INTO TUESDAY. THIS EASILY SUPPORTS MODEL QPF IN THE
RANGE OF 0.25 TO 0.5 INCH BUT STILL PUTS THE NAM UNDER SUSPICION FOR
BEING OVERDEVELOPED WITH ITS SURFACE LOW FOLLOWING ITS 850-500 MB
LAYER OMEGA BULLSEYE. LEANING THE FORECAST TOWARD A MORE LIKELY
TRACK FARTHER SOUTH THEN PRESENTS PRIMARILY A RAIN EVENT FOR THE
DETROIT AREA...A RAIN/SNOW MIX FOR THE M-59 TO I-69 CORRIDOR...AND
THEN MOSTLY SNOW FOR THE SAGINAW VALLEY AND NORTHERN THUMB. SINGLE
DIGIT SNOW RATIO WILL BE A LIMITING FACTOR EVEN THAT FAR NORTH...SO
ACCUMULATION WILL BE SET AT A SLOPPY 1-2 INCHES AS A STARTING
POINT.

THE SECOND HALF OF THE WEEK WILL CONSIST OF A TRANSITION IN THE LONG
WAVE PATTERN FROM THE PERSISTENT RIDGE OUT WEST/TROUGH EAST TO MORE
OF ZONAL CONFIGURATION. THIS WILL BE SET OFF BY THE CURRENT GULF OF
ALASKA LOW MOVING INLAND AND REACHING THE NORTHERN PLAINS WEDNESDAY
INTO THURSDAY. THE LARGE SURFACE LOW PRESSURE PATTERN WILL GENERATE
DEEP SOUTHWEST FLOW EAST OF THE MISSISSIPPI AND A WARMING TREND FOR
LOWER MICHIGAN. GUIDANCE TEMPS LOOK GOOD CALLING FOR HIGHS IN THE
60S THURSDAY BEFORE THE COLD FRONT ARRIVES THURSDAY NIGHT INTO
FRIDAY. THIS FRONT WILL BRING TEMPERATURES BACK BELOW NORMAL HEADING
INTO NEXT WEEKEND.

MARINE...

A GALE WARNING IS IN EFFECT FOR SAGINAW BAY AND CENTRAL LAKE HURON
TODAY AND TONIGHT...AND THROUGH MONDAY AFTERNOON FOR THE NORTH THIRD
OF LAKE HURON. SOUTHWEST GALES WILL DEVELOP AS A LOW PRESSURE SYSTEM
MOVES THROUGH THE NORTHERN GREAT LAKES TODAY. THIS WILL BE FOLLOWED
BY NORTHWEST GALES BEHIND THE ASSOCIATED COLD FRONT OVERNIGHT
THROUGH MONDAY AFTERNOON. THE PRESENCE OF A MODEST AMOUNT OF COLD
AIR IN ADVANCE OF THE LOW...SOME OPEN WATER ON LAKE HURON...AND
FUNNELING IN SAGINAW BAY WILL SUPPORT GALE CONDITIONS. THE SECOND
ROUND OF GALES WILL BE FROM THE NORTHWEST AND WILL BEGIN DURING THE
PREDAWN HOURS MONDAY AND PERSIST THROUGH MIDDAY. TRANQUIL CONDITIONS
WILL TAKE HOLD BENEATH HIGH PRESSURE ON MONDAY NIGHT. THE NEXT LOW
PRESSURE SYSTEM IS DUE IN THE AREA LATE MONDAY NIGHT INTO TUESDAY
BUT WIND SPEED WILL BE LOWER WITH THIS SYSTEM.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WARNING UNTIL MIDNIGHT EDT TONIGHT FOR LHZ363-421-422-441-462.

     SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ442-443.

     GALE WARNING UNTIL 6 PM EDT MONDAY FOR LHZ361-362.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

UPDATE.......KURIMSKI
AVIATION.....CB
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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




000
FXUS63 KDTX 291637
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1237 PM EDT SUN MAR 29 2015

.UPDATE...

THE LINE OF PRECIPITATION OUT OVER LAKE MICHIGAN IS SLOWLY MAKING
ITS WAY EAST THIS AFTERNOON. THE AWIPS TIME OF ARRIVAL TOOL BRINGS
THE LINE OVER THE WESTERN CWA BETWEEN 19-20Z...OR 3-4 PM...QUICKLY
SPREADING ACROSS THE REST OF THE AREA TO THE EASTERN CWA BY 22Z OR
6 PM. GIVEN THE LATEST TRENDS WILL ADJUST THE POP GRIDS TO REFLECT
THE EARLIER TIME OF ARRIVAL.

DESPITE RELATIVELY WARM AFTERNOON TEMPERATURES AROUND 40 DEGREES
THERE IS A VERY DRY AIRMASS IN PLACE AS DEW POINTS RANGE FROM THE
MIDDLE TO UPPER TEENS. THIS SHOULD LEAD TO SOME WET BULBING AS
UPSTREAM OBSERVATIONS HAVE SHOWN A WIDE VARIETY OF PRECIPITATION
TYPES. WITH THE MAIN TYPES BEING RAIN OR SNOW WILL LEAVE THE
CURRENT FORECAST AS IS. REGARDING POPS THE LINE LOOKS SOLID SO 100
POPS ARE STILL APPROPRIATE GIVEN UPSTREAM OBSERVATIONS.

&&

.AVIATION...ISSUED 710 AM EDT SUN MAR 29 2015

A DRY ATMOSPHERE WILL BE IN PLACE THROUGHOUT THE MORNING AND EARLY
AFTERNOON HOURS AHEAD OF AN APPROACHING TROUGH. GROWTH OF THE
BOUNDARY LAYER WILL ALLOW SOUTHWESTERLY SURFACE WINDS TO BECOME
GUSTY WITH WIND SPEEDS LIKELY PUSHING NEAR 30 KNOTS.
PRECIPITATION IS EXPECTED TO ARRIVE SOMETIME AROUND 21Z AT ALL OF
THE TAF SITES AS A LOW LEVEL JET AXIS RAPIDLY LIFTS MOISTURE INTO
THE REGION. STILL SOME QUESTION ON PRECIPITATION TYPE...BUT
STRENGTH OF WARM AIR ADVECTION AND DAYTIME TEMPERATURES SHOULD
SUPPORT MORE LIQUID HYDROMETEOR TYPE. INCLUDED A -SHRASN MENTION
FOR PTK NORTHWARD...BUT NO ACCUMULATION IS EXPECTED. SYSTEM MOTION
IS EXPECTED TO BE VERY FAST WHICH WILL LEAD TO A SHORT
PRECIPITATION DURATION. LOSS OF MIDLEVEL MOISTURE THEN SUGGESTS A
3 TO 6 HOUR WINDOW FOR DRIZZLE AND BR DURING THE MID TO LATE
EVENING.

FOR DTW...VFR UNTIL 22Z-23Z WHEN MVFR CIGS WITH -SHRA WILL BECOME
INCREASINGLY LIKELY. WENT DECIDEDLY MORE PESSIMISTIC WITH CIGS
AFTER 00Z WITH NOCTURNAL COOLING CONTRIBUTIONS LIKELY LOWERING
CIGS INTO IFR. LACK OF MOISTURE DEPTH THEN BRINGS CONCERN FOR -DZ
FOR THE EVENING. SOUTHERLY WINDS FROM 190 TO 200 DEGREES WILL ALSO
GUST TO 25 KNOTS OR BETTER AT TIMES AFTER 18Z SUNDAY.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS AOB 5000 FEET AFTER 22Z-23Z TODAY.

* MEDIUM IN WIND GUSTS TO 25 KNOTS FROM 190-200 DEGREES BY 18Z-20Z
  SUNDAY.

&&

.PREV DISCUSSION...ISSUED 414 AM EDT SUN MAR 29 2015

SHORT TERM...TODAY AND TONIGHT

PRECIPITATION ACTIVITY PUSHING ACROSS THE NORTHERN PLAINS THIS
MORNING IS BEING FORCED BY STRONG WARM AIR ADVECTION AHEAD OF THE
VIGOROUS SHORTWAVE OVER WESTERN NODAK/SODAK. THE MAGNITUDE OF
MOISTURE TRANSPORT ON THE NOSE OF A +70 KNOT LOW LEVEL JET WHILE NOT
SURPRISING...IS NOTEWORTHY FOR TIME OF YEAR WITH PWATS OF UP TO .8
OF AN INCH. NWP DATA MAINTAINS THE STRENGTH OF THIS LLJ AXIS DURING
THE DAYLIGHT HOURS TODAY AND FORECASTS THE ARRIVAL OVER LOWER
MICHIGAN DURING THE AFTERNOON HOURS. THE TIME WINDOW FOR
PRECIPITATION ACROSS SEMICH IS BETWEEN 20-03Z.

12-21Z...IMPRESSIVE DEPTH OF INFLECTION POINT IN FLOW/TROUGH IN
ADDITION TO THE RELATIVELY CLOSE PROXIMITY YET OF THE SE US
ANTICYCLONE WILL ALLOW FOR A STRONG SURFACE PRESSURE GRADIENT BY
THIS AFTERNOON. SHORTWAVE RIDGE AXIS WILL TAKE UNTIL 15Z OR SO TO
PUSH COMPLETELY THROUGH THE CENTRAL GREAT LAKES. SUSPECT IT WILL
TAKE A GROWING BOUNDARY LAYER AND THIS ADDITIONAL SOUTHWESTERLY
GEOSTROPHIC FLOW COMPONENT AT THE MIDLEVELS TO GET GUSTY
SOUTHWESTERLY FLOW TO REALLY INCREASE AT THE SURFACE. SOUTHWESTERLY
WINDS THIS AFTERNOON ARE EXPECTED TO GUST 30 TO 35 MPH. TEMPERATURES
TODAY ARE EXPECTED TO RISE INTO THE LOWER 40S...HIGHEST IN THE
SAGINAW VALLEY/NORTH OF THE GLACIAL TERRAIN.

21-05Z...THE NARRATIVE OF HIGHER CONFIDENCE FOR PRECIPITATION AMOUNTS
REMAINS SOLID (.1 TO .15 OF INCH). ALSO OF HIGHER CONFIDENCE AND
NOTED EARLIER IS THIS EVENT WILL BE GOVERNED BY A VERY FAST SYSTEM
MOTION. THE FAST MOTION WILL NOT ONLY CAUSE A SHORT DURATION OF
PRECIPITATION OVERHEAD...BUT IS ALSO SHOWN TO BE A DETRIMENT TO
CHARACTER/STRENGTH OF THE WARM AIR ADVECTION BY THINNING THE THETA
E RIDGE FOR WHICH THE SYSTEM CAN ACT UPON.

THE MAIN FORECAST QUESTION REMAINS CENTERED ON PRECIPITATION TYPE.
THE 29.00Z MODEL SUITE DID NOT OFFER A WHOLE LOT OF CLARITY ON THIS
SUBJECT...PROBABLY BEST SUMMED UP BY THE HUGE DIFFERENCE THAT
REMAINS IN FORECASTED AFTERNOON SURFACE DEWPOINTS PER MET/MAV. THERE
IS A STRONG MODEL CONSENSUS FOR WETBULB COOLING AT PRECIPITATION
ONSET. IN FACT...RAW MODEL OUTPUT SHOWS SURFACE TEMPERATURES WARMING
MARGINALLY DURING THE MID TO LATE EVENING AFTER PRECIPITATION RATES
DECREASE. CONSENSUS ON MODEL SOUNDINGS IS THAT OF A COLD
PROFILE...WITH LITTLE TO NO WARM SURGE ALOFT. SO...THIS SUGGESTS
PTYPE WILL BE LARGELY DICTATED BY THE DEPTH AND MAGNITUDE OF
SURFACE WARMING TODAY. WITH TEMPS EXPECTED TO REACH THE
40S...SUSPICION AND GUT FEELING IS THE AREA WILL SEE MUCH MORE
LIQUID. HOWEVER...GIVEN THE THERMAL PROFILE AND THE COLD SFC
DEWPOINTS CANNOT RULE OUT SNOW MIXING IN. NOT MUCH OF A CONCERN
WITH LITTLE TO NO ACCUMULATION EXPECTED. THIN NATURE OF THETA E
RIDGE THEN SUPPORTS MOISTURE STRIPPING OUT IN THE MIDLEVELS
ALREADY BY 00Z. THUS...CAN VERY WELL ENVISION A SCENARIO WHERE ICE
NUCLEATION BECOMES A PROBLEM AND SEE A MARKED TRANSITION TO
DRIZZLE DURING THE EVENING.

05-12Z...SECONDARY COLD FRONT STRUCTURE SHOWN TO PUSH THROUGH THE
STATE BETWEEN 05-06Z. THE PASSAGE OF THIS FEATURE SHOULD THEN
DECREASE THE POTENTIAL FOR DRIZZLE DURING THE LATTER HALF OF THE
NIGHT DUE TO DRY AIR ADVECTION. SURFACE TEMPERATURES REMAINING ON
THE WARM SIDE OF THE FREEZING MARK WILL LIMIT THE POTENTIAL
FOR RESIDUAL MOISTURE TO FREEZE.

LONG TERM...

WEAK COLD ADVECTION TRAILING TODAY`S SYSTEM WILL BECOME NEUTRAL
DURING MONDAY MORNING. MODEL SOUNDINGS INDICATE A DEEP BOUNDARY
LAYER GROWING TO NEAR 800 MB BY MID AFTERNOON RESULTING IN NORTHWEST
WIND GUSTING TO AROUND 25 MPH BEFORE THE SURFACE RIDGE ARRIVES LATE
IN THE DAY. THIS...ALONG WITH INCREASING AMOUNTS OF SUNSHINE...WILL
HELP AFTERNOON TEMPS END UP WARMER THAN TODAY WITH HIGHS IN THE MID
TO UPPER 40S OUTSIDE OF THE NORTHERN THUMB.

THE MAIN REASON FOR THE ABBREVIATED COLD ADVECTION MONDAY IS THE
QUICK APPROACH OF THE NEXT RIPPLE OF LOW PRESSURE THROUGH THE PLAINS
AND INTO THE MIDWEST BY MONDAY EVENING. THIS SYSTEM IS DEPICTED IN
THE MODEL DATA AS A SHARD OF UPPER LEVEL ENERGY FROM THE LOW OVER
THE GULF OF ALASKA ROUNDING THE LONG WAVE RIDGE TODAY AND MOVING
THROUGH THE CANADIAN PRAIRIE MONDAY. THE SYSTEM THEN QUICKLY LATCHES
ON TO LOW LEVEL BAROCLINICITY OVER THE NORTHERN PLAINS THAT IS LEFT
OVER FROM TODAY`S SYSTEM. REMNANTS OF THE SURFACE FRONT WILL BE TO
OUR SOUTH BUT THE MID LEVELS OF THE FRONTAL ZONE WILL REMAIN WELL
ORGANIZED OVERHEAD AND TO OUR WEST THROUGH MONDAY. CONSIDERING THE
FAST NORTHWEST FLOW ALOFT...THE WAVE WILL FAVOR A TRACK ALONG THE
700 MB THETA-E GRADIENT. MODEL SOLUTIONS WITH A LOWER AMPLITUDE MID
LEVEL WAVE AND STRONGER FRONTOGENESIS LOOK BEST WHICH LEAVES THE NAM
AS AN OVERDEVELOPED OUTLIER. THE WILDCARD HERE IS THAT THE LOW LEVEL
MOISTURE BROUGHT IN BY TODAY`S SYSTEM IS NEVER REALLY SCOURED OUT
MONDAY AND REMAINS READILY AVAILABLE AT ABOUT 3 G/KG FOR THE SYSTEM
MONDAY NIGHT INTO TUESDAY. THIS EASILY SUPPORTS MODEL QPF IN THE
RANGE OF 0.25 TO 0.5 INCH BUT STILL PUTS THE NAM UNDER SUSPICION FOR
BEING OVERDEVELOPED WITH ITS SURFACE LOW FOLLOWING ITS 850-500 MB
LAYER OMEGA BULLSEYE. LEANING THE FORECAST TOWARD A MORE LIKELY
TRACK FARTHER SOUTH THEN PRESENTS PRIMARILY A RAIN EVENT FOR THE
DETROIT AREA...A RAIN/SNOW MIX FOR THE M-59 TO I-69 CORRIDOR...AND
THEN MOSTLY SNOW FOR THE SAGINAW VALLEY AND NORTHERN THUMB. SINGLE
DIGIT SNOW RATIO WILL BE A LIMITING FACTOR EVEN THAT FAR NORTH...SO
ACCUMULATION WILL BE SET AT A SLOPPY 1-2 INCHES AS A STARTING
POINT.

THE SECOND HALF OF THE WEEK WILL CONSIST OF A TRANSITION IN THE LONG
WAVE PATTERN FROM THE PERSISTENT RIDGE OUT WEST/TROUGH EAST TO MORE
OF ZONAL CONFIGURATION. THIS WILL BE SET OFF BY THE CURRENT GULF OF
ALASKA LOW MOVING INLAND AND REACHING THE NORTHERN PLAINS WEDNESDAY
INTO THURSDAY. THE LARGE SURFACE LOW PRESSURE PATTERN WILL GENERATE
DEEP SOUTHWEST FLOW EAST OF THE MISSISSIPPI AND A WARMING TREND FOR
LOWER MICHIGAN. GUIDANCE TEMPS LOOK GOOD CALLING FOR HIGHS IN THE
60S THURSDAY BEFORE THE COLD FRONT ARRIVES THURSDAY NIGHT INTO
FRIDAY. THIS FRONT WILL BRING TEMPERATURES BACK BELOW NORMAL HEADING
INTO NEXT WEEKEND.

MARINE...

A GALE WARNING IS IN EFFECT FOR SAGINAW BAY AND CENTRAL LAKE HURON
TODAY AND TONIGHT...AND THROUGH MONDAY AFTERNOON FOR THE NORTH THIRD
OF LAKE HURON. SOUTHWEST GALES WILL DEVELOP AS A LOW PRESSURE SYSTEM
MOVES THROUGH THE NORTHERN GREAT LAKES TODAY. THIS WILL BE FOLLOWED
BY NORTHWEST GALES BEHIND THE ASSOCIATED COLD FRONT OVERNIGHT
THROUGH MONDAY AFTERNOON. THE PRESENCE OF A MODEST AMOUNT OF COLD
AIR IN ADVANCE OF THE LOW...SOME OPEN WATER ON LAKE HURON...AND
FUNNELING IN SAGINAW BAY WILL SUPPORT GALE CONDITIONS. THE SECOND
ROUND OF GALES WILL BE FROM THE NORTHWEST AND WILL BEGIN DURING THE
PREDAWN HOURS MONDAY AND PERSIST THROUGH MIDDAY. TRANQUIL CONDITIONS
WILL TAKE HOLD BENEATH HIGH PRESSURE ON MONDAY NIGHT. THE NEXT LOW
PRESSURE SYSTEM IS DUE IN THE AREA LATE MONDAY NIGHT INTO TUESDAY
BUT WIND SPEED WILL BE LOWER WITH THIS SYSTEM.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WARNING UNTIL MIDNIGHT EDT TONIGHT FOR LHZ363-421-422-441-462.

     SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ442-443.

     GALE WARNING UNTIL 6 PM EDT MONDAY FOR LHZ361-362.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

UPDATE.......KURIMSKI
AVIATION.....CB
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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





000
FXUS63 KDTX 291110
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
710 AM EDT SUN MAR 29 2015

.AVIATION...

A DRY ATMOSPHERE WILL BE IN PLACE THROUGHOUT THE MORNING AND EARLY
AFTERNOON HOURS AHEAD OF AN APPROACHING TROUGH. GROWTH OF THE
BOUNDARY LAYER WILL ALLOW SOUTHWESTERLY SURFACE WINDS TO BECOME
GUSTY WITH WIND SPEEDS LIKELY PUSHING NEAR 30 KNOTS.
PRECIPITATION IS EXPECTED TO ARRIVE SOMETIME AROUND 21Z AT ALL OF
THE TAF SITES AS A LOW LEVEL JET AXIS RAPIDLY LIFTS MOISTURE INTO
THE REGION. STILL SOME QUESTION ON PRECIPITATION TYPE...BUT
STRENGTH OF WARM AIR ADVECTION AND DAYTIME TEMPERATURES SHOULD
SUPPORT MORE LIQUID HYDROMETEOR TYPE. INCLUDED A -SHRASN MENTION
FOR PTK NORTHWARD...BUT NO ACCUMULATION IS EXPECTED. SYSTEM MOTION
IS EXPECTED TO BE VERY FAST WHICH WILL LEAD TO A SHORT
PRECIPITATION DURATION. LOSS OF MIDLEVEL MOISTURE THEN SUGGESTS A
3 TO 6 HOUR WINDOW FOR DRIZZLE AND BR DURING THE MID TO LATE
EVENING.

FOR DTW...VFR UNTIL 22Z-23Z WHEN MVFR CIGS WITH -SHRA WILL BECOME
INCREASINGLY LIKELY. WENT DECIDEDLY MORE PESSIMISTIC WITH CIGS
AFTER 00Z WITH NOCTURNAL COOLING CONTRIBUTIONS LIKELY LOWERING
CIGS INTO IFR. LACK OF MOISTURE DEPTH THEN BRINGS CONCERN FOR -DZ
FOR THE EVENING. SOUTHERLY WINDS FROM 190 TO 200 DEGREES WILL ALSO
GUST TO 25 KNOTS OR BETTER AT TIMES AFTER 18Z SUNDAY.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS AOB 5000 FEET AFTER 22Z-23Z TODAY.

* MEDIUM IN WIND GUSTS TO 25 KNOTS FROM 190-200 DEGREES BY 18Z-20Z
  SUNDAY.

&&

.PREV DISCUSSION...ISSUED 414 AM EDT SUN MAR 29 2015

SHORT TERM...TODAY AND TONIGHT

PRECIPITATION ACTIVITY PUSHING ACROSS THE NORTHERN PLAINS THIS
MORNING IS BEING FORCED BY STRONG WARM AIR ADVECTION AHEAD OF THE
VIGOROUS SHORTWAVE OVER WESTERN NODAK/SODAK. THE MAGNITUDE OF
MOISTURE TRANSPORT ON THE NOSE OF A +70 KNOT LOW LEVEL JET WHILE NOT
SURPRISING...IS NOTEWORTHY FOR TIME OF YEAR WITH PWATS OF UP TO .8
OF AN INCH. NWP DATA MAINTAINS THE STRENGTH OF THIS LLJ AXIS DURING
THE DAYLIGHT HOURS TODAY AND FORECASTS THE ARRIVAL OVER LOWER
MICHIGAN DURING THE AFTERNOON HOURS. THE TIME WINDOW FOR
PRECIPITATION ACROSS SEMICH IS BETWEEN 20-03Z.

12-21Z...IMPRESSIVE DEPTH OF INFLECTION POINT IN FLOW/TROUGH IN
ADDITION TO THE RELATIVELY CLOSE PROXIMITY YET OF THE SE US
ANTICYCLONE WILL ALLOW FOR A STRONG SURFACE PRESSURE GRADIENT BY
THIS AFTERNOON. SHORTWAVE RIDGE AXIS WILL TAKE UNTIL 15Z OR SO TO
PUSH COMPLETELY THROUGH THE CENTRAL GREAT LAKES. SUSPECT IT WILL
TAKE A GROWING BOUNDARY LAYER AND THIS ADDITIONAL SOUTHWESTERLY
GEOSTROPHIC FLOW COMPONENT AT THE MIDLEVELS TO GET GUSTY
SOUTHWESTERLY FLOW TO REALLY INCREASE AT THE SURFACE. SOUTHWESTERLY
WINDS THIS AFTERNOON ARE EXPECTED TO GUST 30 TO 35 MPH. TEMPERATURES
TODAY ARE EXPECTED TO RISE INTO THE LOWER 40S...HIGHEST IN THE
SAGINAW VALLEY/NORTH OF THE GLACIAL TERRAIN.

21-05Z...THE NARRATIVE OF HIGHER CONFIDENCE FOR PRECIPITATION AMOUNTS
REMAINS SOLID (.1 TO .15 OF INCH). ALSO OF HIGHER CONFIDENCE AND
NOTED EARLIER IS THIS EVENT WILL BE GOVERNED BY A VERY FAST SYSTEM
MOTION. THE FAST MOTION WILL NOT ONLY CAUSE A SHORT DURATION OF
PRECIPITATION OVERHEAD...BUT IS ALSO SHOWN TO BE A DETRIMENT TO
CHARACTER/STRENGTH OF THE WARM AIR ADVECTION BY THINNING THE THETA
E RIDGE FOR WHICH THE SYSTEM CAN ACT UPON.

THE MAIN FORECAST QUESTION REMAINS CENTERED ON PRECIPITATION TYPE.
THE 29.00Z MODEL SUITE DID NOT OFFER A WHOLE LOT OF CLARITY ON THIS
SUBJECT...PROBABLY BEST SUMMED UP BY THE HUGE DIFFERENCE THAT
REMAINS IN FORECASTED AFTERNOON SURFACE DEWPOINTS PER MET/MAV. THERE
IS A STRONG MODEL CONSENSUS FOR WETBULB COOLING AT PRECIPITATION
ONSET. IN FACT...RAW MODEL OUTPUT SHOWS SURFACE TEMPERATURES WARMING
MARGINALLY DURING THE MID TO LATE EVENING AFTER PRECIPITATION RATES
DECREASE. CONSENSUS ON MODEL SOUNDINGS IS THAT OF A COLD
PROFILE...WITH LITTLE TO NO WARM SURGE ALOFT. SO...THIS SUGGESTS
PTYPE WILL BE LARGELY DICTATED BY THE DEPTH AND MAGNITUDE OF
SURFACE WARMING TODAY. WITH TEMPS EXPECTED TO REACH THE
40S...SUSPICION AND GUT FEELING IS THE AREA WILL SEE MUCH MORE
LIQUID. HOWEVER...GIVEN THE THERMAL PROFILE AND THE COLD SFC
DEWPOINTS CANNOT RULE OUT SNOW MIXING IN. NOT MUCH OF A CONCERN
WITH LITTLE TO NO ACCUMULATION EXPECTED. THIN NATURE OF THETA E
RIDGE THEN SUPPORTS MOISTURE STRIPPING OUT IN THE MIDLEVELS
ALREADY BY 00Z. THUS...CAN VERY WELL ENVISION A SCENARIO WHERE ICE
NUCLEATION BECOMES A PROBLEM AND SEE A MARKED TRANSITION TO
DRIZZLE DURING THE EVENING.

05-12Z...SECONDARY COLD FRONT STRUCTURE SHOWN TO PUSH THROUGH THE
STATE BETWEEN 05-06Z. THE PASSAGE OF THIS FEATURE SHOULD THEN
DECREASE THE POTENTIAL FOR DRIZZLE DURING THE LATTER HALF OF THE
NIGHT DUE TO DRY AIR ADVECTION. SURFACE TEMPERATURES REMAINING ON
THE WARM SIDE OF THE FREEZING MARK WILL LIMIT THE POTENTIAL
FOR RESIDUAL MOISTURE TO FREEZE.

LONG TERM...

WEAK COLD ADVECTION TRAILING TODAY`S SYSTEM WILL BECOME NEUTRAL
DURING MONDAY MORNING. MODEL SOUNDINGS INDICATE A DEEP BOUNDARY
LAYER GROWING TO NEAR 800 MB BY MID AFTERNOON RESULTING IN NORTHWEST
WIND GUSTING TO AROUND 25 MPH BEFORE THE SURFACE RIDGE ARRIVES LATE
IN THE DAY. THIS...ALONG WITH INCREASING AMOUNTS OF SUNSHINE...WILL
HELP AFTERNOON TEMPS END UP WARMER THAN TODAY WITH HIGHS IN THE MID
TO UPPER 40S OUTSIDE OF THE NORTHERN THUMB.

THE MAIN REASON FOR THE ABBREVIATED COLD ADVECTION MONDAY IS THE
QUICK APPROACH OF THE NEXT RIPPLE OF LOW PRESSURE THROUGH THE PLAINS
AND INTO THE MIDWEST BY MONDAY EVENING. THIS SYSTEM IS DEPICTED IN
THE MODEL DATA AS A SHARD OF UPPER LEVEL ENERGY FROM THE LOW OVER
THE GULF OF ALASKA ROUNDING THE LONG WAVE RIDGE TODAY AND MOVING
THROUGH THE CANADIAN PRAIRIE MONDAY. THE SYSTEM THEN QUICKLY LATCHES
ON TO LOW LEVEL BAROCLINICITY OVER THE NORTHERN PLAINS THAT IS LEFT
OVER FROM TODAY`S SYSTEM. REMNANTS OF THE SURFACE FRONT WILL BE TO
OUR SOUTH BUT THE MID LEVELS OF THE FRONTAL ZONE WILL REMAIN WELL
ORGANIZED OVERHEAD AND TO OUR WEST THROUGH MONDAY. CONSIDERING THE
FAST NORTHWEST FLOW ALOFT...THE WAVE WILL FAVOR A TRACK ALONG THE
700 MB THETA-E GRADIENT. MODEL SOLUTIONS WITH A LOWER AMPLITUDE MID
LEVEL WAVE AND STRONGER FRONTOGENESIS LOOK BEST WHICH LEAVES THE NAM
AS AN OVERDEVELOPED OUTLIER. THE WILDCARD HERE IS THAT THE LOW LEVEL
MOISTURE BROUGHT IN BY TODAY`S SYSTEM IS NEVER REALLY SCOURED OUT
MONDAY AND REMAINS READILY AVAILABLE AT ABOUT 3 G/KG FOR THE SYSTEM
MONDAY NIGHT INTO TUESDAY. THIS EASILY SUPPORTS MODEL QPF IN THE
RANGE OF 0.25 TO 0.5 INCH BUT STILL PUTS THE NAM UNDER SUSPICION FOR
BEING OVERDEVELOPED WITH ITS SURFACE LOW FOLLOWING ITS 850-500 MB
LAYER OMEGA BULLSEYE. LEANING THE FORECAST TOWARD A MORE LIKELY
TRACK FARTHER SOUTH THEN PRESENTS PRIMARILY A RAIN EVENT FOR THE
DETROIT AREA...A RAIN/SNOW MIX FOR THE M-59 TO I-69 CORRIDOR...AND
THEN MOSTLY SNOW FOR THE SAGINAW VALLEY AND NORTHERN THUMB. SINGLE
DIGIT SNOW RATIO WILL BE A LIMITING FACTOR EVEN THAT FAR NORTH...SO
ACCUMULATION WILL BE SET AT A SLOPPY 1-2 INCHES AS A STARTING
POINT.

THE SECOND HALF OF THE WEEK WILL CONSIST OF A TRANSITION IN THE LONG
WAVE PATTERN FROM THE PERSISTENT RIDGE OUT WEST/TROUGH EAST TO MORE
OF ZONAL CONFIGURATION. THIS WILL BE SET OFF BY THE CURRENT GULF OF
ALASKA LOW MOVING INLAND AND REACHING THE NORTHERN PLAINS WEDNESDAY
INTO THURSDAY. THE LARGE SURFACE LOW PRESSURE PATTERN WILL GENERATE
DEEP SOUTHWEST FLOW EAST OF THE MISSISSIPPI AND A WARMING TREND FOR
LOWER MICHIGAN. GUIDANCE TEMPS LOOK GOOD CALLING FOR HIGHS IN THE
60S THURSDAY BEFORE THE COLD FRONT ARRIVES THURSDAY NIGHT INTO
FRIDAY. THIS FRONT WILL BRING TEMPERATURES BACK BELOW NORMAL HEADING
INTO NEXT WEEKEND.

MARINE...

A GALE WARNING IS IN EFFECT FOR SAGINAW BAY AND CENTRAL LAKE HURON
TODAY AND TONIGHT...AND THROUGH MONDAY AFTERNOON FOR THE NORTH THIRD
OF LAKE HURON. SOUTHWEST GALES WILL DEVELOP AS A LOW PRESSURE SYSTEM
MOVES THROUGH THE NORTHERN GREAT LAKES TODAY. THIS WILL BE FOLLOWED
BY NORTHWEST GALES BEHIND THE ASSOCIATED COLD FRONT OVERNIGHT
THROUGH MONDAY AFTERNOON. THE PRESENCE OF A MODEST AMOUNT OF COLD
AIR IN ADVANCE OF THE LOW...SOME OPEN WATER ON LAKE HURON...AND
FUNNELING IN SAGINAW BAY WILL SUPPORT GALE CONDITIONS. THE SECOND
ROUND OF GALES WILL BE FROM THE NORTHWEST AND WILL BEGIN DURING THE
PREDAWN HOURS MONDAY AND PERSIST THROUGH MIDDAY. TRANQUIL CONDITIONS
WILL TAKE HOLD BENEATH HIGH PRESSURE ON MONDAY NIGHT. THE NEXT LOW
PRESSURE SYSTEM IS DUE IN THE AREA LATE MONDAY NIGHT INTO TUESDAY
BUT WIND SPEED WILL BE LOWER WITH THIS SYSTEM.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

MI...NONE.

LAKE HURON...GALE WARNING FROM NOON TODAY TO MIDNIGHT EDT TONIGHT FOR LHZ363-421-
     422-441-462.

     GALE WARNING FROM NOON TODAY TO 6 PM EDT MONDAY FOR LHZ361-362.

LAKE ST CLAIR...NONE.

MICHIGAN WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....CB
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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





000
FXUS63 KDTX 291110
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
710 AM EDT SUN MAR 29 2015

.AVIATION...

A DRY ATMOSPHERE WILL BE IN PLACE THROUGHOUT THE MORNING AND EARLY
AFTERNOON HOURS AHEAD OF AN APPROACHING TROUGH. GROWTH OF THE
BOUNDARY LAYER WILL ALLOW SOUTHWESTERLY SURFACE WINDS TO BECOME
GUSTY WITH WIND SPEEDS LIKELY PUSHING NEAR 30 KNOTS.
PRECIPITATION IS EXPECTED TO ARRIVE SOMETIME AROUND 21Z AT ALL OF
THE TAF SITES AS A LOW LEVEL JET AXIS RAPIDLY LIFTS MOISTURE INTO
THE REGION. STILL SOME QUESTION ON PRECIPITATION TYPE...BUT
STRENGTH OF WARM AIR ADVECTION AND DAYTIME TEMPERATURES SHOULD
SUPPORT MORE LIQUID HYDROMETEOR TYPE. INCLUDED A -SHRASN MENTION
FOR PTK NORTHWARD...BUT NO ACCUMULATION IS EXPECTED. SYSTEM MOTION
IS EXPECTED TO BE VERY FAST WHICH WILL LEAD TO A SHORT
PRECIPITATION DURATION. LOSS OF MIDLEVEL MOISTURE THEN SUGGESTS A
3 TO 6 HOUR WINDOW FOR DRIZZLE AND BR DURING THE MID TO LATE
EVENING.

FOR DTW...VFR UNTIL 22Z-23Z WHEN MVFR CIGS WITH -SHRA WILL BECOME
INCREASINGLY LIKELY. WENT DECIDEDLY MORE PESSIMISTIC WITH CIGS
AFTER 00Z WITH NOCTURNAL COOLING CONTRIBUTIONS LIKELY LOWERING
CIGS INTO IFR. LACK OF MOISTURE DEPTH THEN BRINGS CONCERN FOR -DZ
FOR THE EVENING. SOUTHERLY WINDS FROM 190 TO 200 DEGREES WILL ALSO
GUST TO 25 KNOTS OR BETTER AT TIMES AFTER 18Z SUNDAY.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS AOB 5000 FEET AFTER 22Z-23Z TODAY.

* MEDIUM IN WIND GUSTS TO 25 KNOTS FROM 190-200 DEGREES BY 18Z-20Z
  SUNDAY.

&&

.PREV DISCUSSION...ISSUED 414 AM EDT SUN MAR 29 2015

SHORT TERM...TODAY AND TONIGHT

PRECIPITATION ACTIVITY PUSHING ACROSS THE NORTHERN PLAINS THIS
MORNING IS BEING FORCED BY STRONG WARM AIR ADVECTION AHEAD OF THE
VIGOROUS SHORTWAVE OVER WESTERN NODAK/SODAK. THE MAGNITUDE OF
MOISTURE TRANSPORT ON THE NOSE OF A +70 KNOT LOW LEVEL JET WHILE NOT
SURPRISING...IS NOTEWORTHY FOR TIME OF YEAR WITH PWATS OF UP TO .8
OF AN INCH. NWP DATA MAINTAINS THE STRENGTH OF THIS LLJ AXIS DURING
THE DAYLIGHT HOURS TODAY AND FORECASTS THE ARRIVAL OVER LOWER
MICHIGAN DURING THE AFTERNOON HOURS. THE TIME WINDOW FOR
PRECIPITATION ACROSS SEMICH IS BETWEEN 20-03Z.

12-21Z...IMPRESSIVE DEPTH OF INFLECTION POINT IN FLOW/TROUGH IN
ADDITION TO THE RELATIVELY CLOSE PROXIMITY YET OF THE SE US
ANTICYCLONE WILL ALLOW FOR A STRONG SURFACE PRESSURE GRADIENT BY
THIS AFTERNOON. SHORTWAVE RIDGE AXIS WILL TAKE UNTIL 15Z OR SO TO
PUSH COMPLETELY THROUGH THE CENTRAL GREAT LAKES. SUSPECT IT WILL
TAKE A GROWING BOUNDARY LAYER AND THIS ADDITIONAL SOUTHWESTERLY
GEOSTROPHIC FLOW COMPONENT AT THE MIDLEVELS TO GET GUSTY
SOUTHWESTERLY FLOW TO REALLY INCREASE AT THE SURFACE. SOUTHWESTERLY
WINDS THIS AFTERNOON ARE EXPECTED TO GUST 30 TO 35 MPH. TEMPERATURES
TODAY ARE EXPECTED TO RISE INTO THE LOWER 40S...HIGHEST IN THE
SAGINAW VALLEY/NORTH OF THE GLACIAL TERRAIN.

21-05Z...THE NARRATIVE OF HIGHER CONFIDENCE FOR PRECIPITATION AMOUNTS
REMAINS SOLID (.1 TO .15 OF INCH). ALSO OF HIGHER CONFIDENCE AND
NOTED EARLIER IS THIS EVENT WILL BE GOVERNED BY A VERY FAST SYSTEM
MOTION. THE FAST MOTION WILL NOT ONLY CAUSE A SHORT DURATION OF
PRECIPITATION OVERHEAD...BUT IS ALSO SHOWN TO BE A DETRIMENT TO
CHARACTER/STRENGTH OF THE WARM AIR ADVECTION BY THINNING THE THETA
E RIDGE FOR WHICH THE SYSTEM CAN ACT UPON.

THE MAIN FORECAST QUESTION REMAINS CENTERED ON PRECIPITATION TYPE.
THE 29.00Z MODEL SUITE DID NOT OFFER A WHOLE LOT OF CLARITY ON THIS
SUBJECT...PROBABLY BEST SUMMED UP BY THE HUGE DIFFERENCE THAT
REMAINS IN FORECASTED AFTERNOON SURFACE DEWPOINTS PER MET/MAV. THERE
IS A STRONG MODEL CONSENSUS FOR WETBULB COOLING AT PRECIPITATION
ONSET. IN FACT...RAW MODEL OUTPUT SHOWS SURFACE TEMPERATURES WARMING
MARGINALLY DURING THE MID TO LATE EVENING AFTER PRECIPITATION RATES
DECREASE. CONSENSUS ON MODEL SOUNDINGS IS THAT OF A COLD
PROFILE...WITH LITTLE TO NO WARM SURGE ALOFT. SO...THIS SUGGESTS
PTYPE WILL BE LARGELY DICTATED BY THE DEPTH AND MAGNITUDE OF
SURFACE WARMING TODAY. WITH TEMPS EXPECTED TO REACH THE
40S...SUSPICION AND GUT FEELING IS THE AREA WILL SEE MUCH MORE
LIQUID. HOWEVER...GIVEN THE THERMAL PROFILE AND THE COLD SFC
DEWPOINTS CANNOT RULE OUT SNOW MIXING IN. NOT MUCH OF A CONCERN
WITH LITTLE TO NO ACCUMULATION EXPECTED. THIN NATURE OF THETA E
RIDGE THEN SUPPORTS MOISTURE STRIPPING OUT IN THE MIDLEVELS
ALREADY BY 00Z. THUS...CAN VERY WELL ENVISION A SCENARIO WHERE ICE
NUCLEATION BECOMES A PROBLEM AND SEE A MARKED TRANSITION TO
DRIZZLE DURING THE EVENING.

05-12Z...SECONDARY COLD FRONT STRUCTURE SHOWN TO PUSH THROUGH THE
STATE BETWEEN 05-06Z. THE PASSAGE OF THIS FEATURE SHOULD THEN
DECREASE THE POTENTIAL FOR DRIZZLE DURING THE LATTER HALF OF THE
NIGHT DUE TO DRY AIR ADVECTION. SURFACE TEMPERATURES REMAINING ON
THE WARM SIDE OF THE FREEZING MARK WILL LIMIT THE POTENTIAL
FOR RESIDUAL MOISTURE TO FREEZE.

LONG TERM...

WEAK COLD ADVECTION TRAILING TODAY`S SYSTEM WILL BECOME NEUTRAL
DURING MONDAY MORNING. MODEL SOUNDINGS INDICATE A DEEP BOUNDARY
LAYER GROWING TO NEAR 800 MB BY MID AFTERNOON RESULTING IN NORTHWEST
WIND GUSTING TO AROUND 25 MPH BEFORE THE SURFACE RIDGE ARRIVES LATE
IN THE DAY. THIS...ALONG WITH INCREASING AMOUNTS OF SUNSHINE...WILL
HELP AFTERNOON TEMPS END UP WARMER THAN TODAY WITH HIGHS IN THE MID
TO UPPER 40S OUTSIDE OF THE NORTHERN THUMB.

THE MAIN REASON FOR THE ABBREVIATED COLD ADVECTION MONDAY IS THE
QUICK APPROACH OF THE NEXT RIPPLE OF LOW PRESSURE THROUGH THE PLAINS
AND INTO THE MIDWEST BY MONDAY EVENING. THIS SYSTEM IS DEPICTED IN
THE MODEL DATA AS A SHARD OF UPPER LEVEL ENERGY FROM THE LOW OVER
THE GULF OF ALASKA ROUNDING THE LONG WAVE RIDGE TODAY AND MOVING
THROUGH THE CANADIAN PRAIRIE MONDAY. THE SYSTEM THEN QUICKLY LATCHES
ON TO LOW LEVEL BAROCLINICITY OVER THE NORTHERN PLAINS THAT IS LEFT
OVER FROM TODAY`S SYSTEM. REMNANTS OF THE SURFACE FRONT WILL BE TO
OUR SOUTH BUT THE MID LEVELS OF THE FRONTAL ZONE WILL REMAIN WELL
ORGANIZED OVERHEAD AND TO OUR WEST THROUGH MONDAY. CONSIDERING THE
FAST NORTHWEST FLOW ALOFT...THE WAVE WILL FAVOR A TRACK ALONG THE
700 MB THETA-E GRADIENT. MODEL SOLUTIONS WITH A LOWER AMPLITUDE MID
LEVEL WAVE AND STRONGER FRONTOGENESIS LOOK BEST WHICH LEAVES THE NAM
AS AN OVERDEVELOPED OUTLIER. THE WILDCARD HERE IS THAT THE LOW LEVEL
MOISTURE BROUGHT IN BY TODAY`S SYSTEM IS NEVER REALLY SCOURED OUT
MONDAY AND REMAINS READILY AVAILABLE AT ABOUT 3 G/KG FOR THE SYSTEM
MONDAY NIGHT INTO TUESDAY. THIS EASILY SUPPORTS MODEL QPF IN THE
RANGE OF 0.25 TO 0.5 INCH BUT STILL PUTS THE NAM UNDER SUSPICION FOR
BEING OVERDEVELOPED WITH ITS SURFACE LOW FOLLOWING ITS 850-500 MB
LAYER OMEGA BULLSEYE. LEANING THE FORECAST TOWARD A MORE LIKELY
TRACK FARTHER SOUTH THEN PRESENTS PRIMARILY A RAIN EVENT FOR THE
DETROIT AREA...A RAIN/SNOW MIX FOR THE M-59 TO I-69 CORRIDOR...AND
THEN MOSTLY SNOW FOR THE SAGINAW VALLEY AND NORTHERN THUMB. SINGLE
DIGIT SNOW RATIO WILL BE A LIMITING FACTOR EVEN THAT FAR NORTH...SO
ACCUMULATION WILL BE SET AT A SLOPPY 1-2 INCHES AS A STARTING
POINT.

THE SECOND HALF OF THE WEEK WILL CONSIST OF A TRANSITION IN THE LONG
WAVE PATTERN FROM THE PERSISTENT RIDGE OUT WEST/TROUGH EAST TO MORE
OF ZONAL CONFIGURATION. THIS WILL BE SET OFF BY THE CURRENT GULF OF
ALASKA LOW MOVING INLAND AND REACHING THE NORTHERN PLAINS WEDNESDAY
INTO THURSDAY. THE LARGE SURFACE LOW PRESSURE PATTERN WILL GENERATE
DEEP SOUTHWEST FLOW EAST OF THE MISSISSIPPI AND A WARMING TREND FOR
LOWER MICHIGAN. GUIDANCE TEMPS LOOK GOOD CALLING FOR HIGHS IN THE
60S THURSDAY BEFORE THE COLD FRONT ARRIVES THURSDAY NIGHT INTO
FRIDAY. THIS FRONT WILL BRING TEMPERATURES BACK BELOW NORMAL HEADING
INTO NEXT WEEKEND.

MARINE...

A GALE WARNING IS IN EFFECT FOR SAGINAW BAY AND CENTRAL LAKE HURON
TODAY AND TONIGHT...AND THROUGH MONDAY AFTERNOON FOR THE NORTH THIRD
OF LAKE HURON. SOUTHWEST GALES WILL DEVELOP AS A LOW PRESSURE SYSTEM
MOVES THROUGH THE NORTHERN GREAT LAKES TODAY. THIS WILL BE FOLLOWED
BY NORTHWEST GALES BEHIND THE ASSOCIATED COLD FRONT OVERNIGHT
THROUGH MONDAY AFTERNOON. THE PRESENCE OF A MODEST AMOUNT OF COLD
AIR IN ADVANCE OF THE LOW...SOME OPEN WATER ON LAKE HURON...AND
FUNNELING IN SAGINAW BAY WILL SUPPORT GALE CONDITIONS. THE SECOND
ROUND OF GALES WILL BE FROM THE NORTHWEST AND WILL BEGIN DURING THE
PREDAWN HOURS MONDAY AND PERSIST THROUGH MIDDAY. TRANQUIL CONDITIONS
WILL TAKE HOLD BENEATH HIGH PRESSURE ON MONDAY NIGHT. THE NEXT LOW
PRESSURE SYSTEM IS DUE IN THE AREA LATE MONDAY NIGHT INTO TUESDAY
BUT WIND SPEED WILL BE LOWER WITH THIS SYSTEM.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

MI...NONE.

LAKE HURON...GALE WARNING FROM NOON TODAY TO MIDNIGHT EDT TONIGHT FOR LHZ363-421-
     422-441-462.

     GALE WARNING FROM NOON TODAY TO 6 PM EDT MONDAY FOR LHZ361-362.

LAKE ST CLAIR...NONE.

MICHIGAN WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....CB
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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




000
FXUS63 KDTX 290814
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
414 AM EDT SUN MAR 29 2015

.SHORT TERM...TODAY AND TONIGHT

PRECIPITATION ACTIVITY PUSHING ACROSS THE NORTHERN PLAINS THIS
MORNING IS BEING FORCED BY STRONG WARM AIR ADVECTION AHEAD OF THE
VIGOROUS SHORTWAVE OVER WESTERN NODAK/SODAK. THE MAGNITUDE OF
MOISTURE TRANSPORT ON THE NOSE OF A +70 KNOT LOW LEVEL JET WHILE NOT
SURPRISING...IS NOTEWORTHY FOR TIME OF YEAR WITH PWATS OF UP TO .8
OF AN INCH. NWP DATA MAINTAINS THE STRENGTH OF THIS LLJ AXIS DURING
THE DAYLIGHT HOURS TODAY AND FORECASTS THE ARRIVAL OVER LOWER
MICHIGAN DURING THE AFTERNOON HOURS. THE TIME WINDOW FOR PRECIPATION
ACROSS SEMICH IS BETWEEN 20-03Z.

12-21Z...IMPRESSIVE DEPTH OF INFLECTION POINT IN FLOW/TROUGH IN
ADDITION TO THE RELATIVELY CLOSE PROXIMITY YET OF THE SE US
ANTICYCLONE WILL ALLOW FOR A STRONG SURFACE PRESSURE GRADIENT BY
THIS AFTERNOON. SHORTWAVE RIDGE AXIS WILL TAKE UNTIL 15Z OR SO TO
PUSH COMPLETELY THROUGH THE CENTRAL GREAT LAKES. SUSPECT IT WILL
TAKE A GROWING BOUNDARY LAYER AND THIS ADDITIONAL SOUTHWESTERLY
GEOSTROPHIC FLOW COMPONENT AT THE MIDLEVELS TO GET GUSTY
SOUTHWESTERLY FLOW TO REALLY INCREASE AT THE SURFACE. SOUTHWESTERLY
WINDS THIS AFTERNOON ARE EXPECTED TO GUST 30 TO 35 MPH. TEMPERATURES
TODAY ARE EXPECTED TO RISE INTO THE LOWER 40S...HIGHEST IN THE
SAGINAW VALLEY/NORTH OF THE GLACIAL TERRAIN.

21-05Z...THE NARRATIVE OF HIGHER CONFIDENCE FOR PRECIPATION AMOUNTS
REMAINS SOLID (.1 TO .15 OF INCH). ALSO OF HIGHER CONFIDENCE AND
NOTED EARLIER IS THIS EVENT WILL BE GOVERNED BY A VERY FAST SYSTEM
MOTION. THE FAST MOTION WILL NOT ONLY CAUSE A SHORT DURATION OF
PRECIPATION OVERHEAD...BUT IS ALSO SHOWN TO BE A DETRIMENT TO
CHARACTER/STRENGTH OF THE WARM AIR ADVECTION BY THINNING THE THETA E
RIDGE FOR WHICH THE SYSTEM CAN ACT UPON.

THE MAIN FORECAST QUESTION REMAINS CENTERED ON PRECIPITATION TYPE.
THE 29.00Z MODEL SUITE DID NOT OFFER A WHOLE LOT OF CLARITY ON THIS
SUBJECT...PROBABLY BEST SUMMED UP BY THE HUGE DIFFERENCE THAT
REMAINS IN FORECASTED AFTERNOON SURFACE DEWPOINTS PER MET/MAV. THERE
IS A STRONG MODEL CONSENSUS FOR WETBULB COOLING AT PRECIPATION
ONSET. IN FACT...RAW MODEL OUTPUT SHOWS SURFACE TEMPERATURES WARMING
MARGINALLY DURING THE MID TO LATE EVENING AFTER PRECIPATION RATES
DECREASE. CONSENSUS ON MODEL SOUNDINGS IS THAT OF A COLD
PROFILE...WITH LITTLE TO NO WARM SURGE ALOFT. SO...THIS SUGGESTS
PTYPE WILL BE LARGELY DICTATED BY THE DEPTH AND MAGNITUDE OF SURFACE
WARMING TODAY. WITH TEMPS EXPECTED TO REACH THE 40S...SUSPICION AND
GUT FEELING IS THE AREA WILL SEE MUCH MORE LIQUID. HOWEVER...GIVEN
THE THERMAL PROFILE AND THE COLD SFC DEWPONTS CANNOT RULE OUT SNOW
MIXING IN. NOT MUCH OF A CONCERN WITH LITTLE TO NO ACCUMULATION
EXPECTED. THIN NATURE OF THETA E RIDGE THEN SUPPORTS MOISTURE
STRIPPING OUT IN THE MIDLEVELS ALREADY BY 00Z. THUS...CAN VERY WELL
ENVISION A SCENARIO WHERE ICE NUCLEATION BECOMES A PROBLEM AND SEE A
MARKED TRANSITION TO DRIZZLE DURING THE EVENING.

05-12Z...SECONDARY COLD FRONT STRUCTURE SHOWN TO PUSH THROUGH THE
STATE BETWEEN 05-06Z. THE PASSAGE OF THIS FEATURE SHOULD THEN
DECREASE THE POTENTIAL FOR DRIZZLE DURING THE LATTER HALF OF THE
NIGHT DUE TO DRY AIR ADVECTION. SURFACE TEMPERATURES REMAINING ON
THE WARM SIDE OF THE FREEZING MARK WILL LIMIT THE POTENTIAL
FOR RESIDUAL MOISTURE TO FREEZE.

&&

.LONG TERM...

WEAK COLD ADVECTION TRAILING TODAY`S SYSTEM WILL BECOME NEUTRAL
DURING MONDAY MORNING. MODEL SOUNDINGS INDICATE A DEEP BOUNDARY
LAYER GROWING TO NEAR 800 MB BY MID AFTERNOON RESULTING IN NORTHWEST
WIND GUSTING TO AROUND 25 MPH BEFORE THE SURFACE RIDGE ARRIVES LATE
IN THE DAY. THIS...ALONG WITH INCREASING AMOUNTS OF SUNSHINE...WILL
HELP AFTERNOON TEMPS END UP WARMER THAN TODAY WITH HIGHS IN THE MID
TO UPPER 40S OUTSIDE OF THE NORTHERN THUMB.

THE MAIN REASON FOR THE ABBREVIATED COLD ADVECTION MONDAY IS THE
QUICK APPROACH OF THE NEXT RIPPLE OF LOW PRESSURE THROUGH THE PLAINS
AND INTO THE MIDWEST BY MONDAY EVENING. THIS SYSTEM IS DEPICTED IN
THE MODEL DATA AS A SHARD OF UPPER LEVEL ENERGY FROM THE LOW OVER
THE GULF OF ALASKA ROUNDING THE LONG WAVE RIDGE TODAY AND MOVING
THROUGH THE CANADIAN PRAIRIE MONDAY. THE SYSTEM THEN QUICKLY LATCHES
ON TO LOW LEVEL BAROCLINICITY OVER THE NORTHERN PLAINS THAT IS LEFT
OVER FROM TODAY`S SYSTEM. REMNANTS OF THE SURFACE FRONT WILL BE TO
OUR SOUTH BUT THE MID LEVELS OF THE FRONTAL ZONE WILL REMAIN WELL
ORGANIZED OVERHEAD AND TO OUR WEST THROUGH MONDAY. CONSIDERING THE
FAST NORTHWEST FLOW ALOFT...THE WAVE WILL FAVOR A TRACK ALONG THE
700 MB THETA-E GRADIENT. MODEL SOLUTIONS WITH A LOWER AMPLITUDE MID
LEVEL WAVE AND STRONGER FRONTOGENESIS LOOK BEST WHICH LEAVES THE NAM
AS AN OVERDEVELOPED OUTLIER. THE WILDCARD HERE IS THAT THE LOW LEVEL
MOISTURE BROUGHT IN BY TODAY`S SYSTEM IS NEVER REALLY SCOURED OUT
MONDAY AND REMAINS READILY AVAILABLE AT ABOUT 3 G/KG FOR THE SYSTEM
MONDAY NIGHT INTO TUESDAY. THIS EASILY SUPPORTS MODEL QPF IN THE
RANGE OF 0.25 TO 0.5 INCH BUT STILL PUTS THE NAM UNDER SUSPICION FOR
BEING OVERDEVELOPED WITH ITS SURFACE LOW FOLLOWING ITS 850-500 MB
LAYER OMEGA BULLSEYE. LEANING THE FORECAST TOWARD A MORE LIKELY
TRACK FARTHER SOUTH THEN PRESENTS PRIMARILY A RAIN EVENT FOR THE
DETROIT AREA...A RAIN/SNOW MIX FOR THE M-59 TO I-69 CORRIDOR...AND
THEN MOSTLY SNOW FOR THE SAGINAW VALLEY AND NORTHERN THUMB. SINGLE
DIGIT SNOW RATIO WILL BE A LIMITING FACTOR EVEN THAT FAR NORTH...SO
ACCUMULATION WILL BE SET AT A SLOPPY 1-2 INCHES AS A STARTING
POINT.

THE SECOND HALF OF THE WEEK WILL CONSIST OF A TRANSITION IN THE LONG
WAVE PATTERN FROM THE PERSISTENT RIDGE OUT WEST/TROUGH EAST TO MORE
OF ZONAL CONFIGURATION. THIS WILL BE SET OFF BY THE CURRENT GULF OF
ALASKA LOW MOVING INLAND AND REACHING THE NORTHERN PLAINS WEDNESDAY
INTO THURSDAY. THE LARGE SURFACE LOW PRESSURE PATTERN WILL GENERATE
DEEP SOUTHWEST FLOW EAST OF THE MISSISSIPPI AND A WARMING TREND FOR
LOWER MICHIGAN. GUIDANCE TEMPS LOOK GOOD CALLING FOR HIGHS IN THE
60S THURSDAY BEFORE THE COLD FRONT ARRIVES THURSDAY NIGHT INTO
FRIDAY. THIS FRONT WILL BRING TEMPERATURES BACK BELOW NORMAL HEADING
INTO NEXT WEEKEND.

&&

.MARINE...

A GALE WARNING IS IN EFFECT FOR SAGINAW BAY AND CENTRAL LAKE HURON
TODAY AND TONIGHT...AND THROUGH MONDAY AFTERNOON FOR THE NORTH THIRD
OF LAKE HURON. SOUTHWEST GALES WILL DEVELOP AS A LOW PRESSURE SYSTEM
MOVES THROUGH THE NORTHERN GREAT LAKES TODAY. THIS WILL BE FOLLOWED
BY NORTHWEST GALES BEHIND THE ASSOCIATED COLD FRONT OVERNIGHT
THROUGH MONDAY AFTERNOON. THE PRESENCE OF A MODEST AMOUNT OF COLD
AIR IN ADVANCE OF THE LOW...SOME OPEN WATER ON LAKE HURON...AND
FUNNELING IN SAGINAW BAY WILL SUPPORT GALE CONDITIONS. THE SECOND
ROUND OF GALES WILL BE FROM THE NORTHWEST AND WILL BEGIN DURING THE
PREDAWN HOURS MONDAY AND PERSIST THROUGH MIDDAY. TRANQUIL CONDITIONS
WILL TAKE HOLD BENEATH HIGH PRESSURE ON MONDAY NIGHT. THE NEXT LOW
PRESSURE SYSTEM IS DUE IN THE AREA LATE MONDAY NIGHT INTO TUESDAY
BUT WIND SPEED WILL BE LOWER WITH THIS SYSTEM.

&&

.AVIATION...ISSUED 1201 AM EDT SUN MAR 29 2015

VFR CONDITIONS WILL PREVAIL INTO MID SUNDAY AFTERNOON BEFORE AN
APPROACHING TROUGH BRINGS MVFR CIGS AND -SHRA OR -SHRASN BY 20Z TO
22Z OR SO. THIS ACTIVITY LOOKS TO LAST ABOUT 4-6 HOURS AS THIS
FEATURE PASSES THROUGH THE AREA. A STRENGTHENING PRESSURE GRADIENT
WILL ALSO LEAD TO STRONG SOUTHERLY FLOW BY AFTERNOON WITH GUSTS TO
NEAR 30 KNOTS. GENERALLY BREEZY CONDITIONS WILL THEN PERSIST INTO
EARLY EVENING AS WINDS VEER TO SW WITH THE PASSAGE OF THE TROUGH.
MVFR TO LOWER VFR CIGS WILL PERSIST INTO THE NIGHT WITHIN WESTERLY
FLOW BEHIND EXITING SYSTEM.

FOR DTW...VFR UNTIL 21Z-22Z OR SO SUNDAY WHEN MVFR CIGS WITH -SHRA
WILL BECOME INCREASINGLY LIKELY. SOUTHERLY WINDS FROM 190 TO 200
DEGREES WILL ALSO GUST TO 25 KNOTS OR BETTER AT TIMES AFTER 18Z
SUNDAY.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN CEILINGS AOB 5000 FEET AFTER 21Z-22Z SUNDAY.

* MEDIUM IN WIND GUSTS TO 25 KNOTS FROM 190-200 DEGREES BY 18Z-20Z
  SUNDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WARNING FROM NOON TODAY TO MIDNIGHT EDT TONIGHT FOR LHZ363-421-
     422-441-462.

     GALE WARNING FROM NOON TODAY TO 6 PM EDT MONDAY FOR LHZ361-362.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

SHORT TERM...CB
LONG TERM....BT
MARINE.......BT
AVIATION.....CB


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





000
FXUS63 KDTX 290814
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
414 AM EDT SUN MAR 29 2015

.SHORT TERM...TODAY AND TONIGHT

PRECIPITATION ACTIVITY PUSHING ACROSS THE NORTHERN PLAINS THIS
MORNING IS BEING FORCED BY STRONG WARM AIR ADVECTION AHEAD OF THE
VIGOROUS SHORTWAVE OVER WESTERN NODAK/SODAK. THE MAGNITUDE OF
MOISTURE TRANSPORT ON THE NOSE OF A +70 KNOT LOW LEVEL JET WHILE NOT
SURPRISING...IS NOTEWORTHY FOR TIME OF YEAR WITH PWATS OF UP TO .8
OF AN INCH. NWP DATA MAINTAINS THE STRENGTH OF THIS LLJ AXIS DURING
THE DAYLIGHT HOURS TODAY AND FORECASTS THE ARRIVAL OVER LOWER
MICHIGAN DURING THE AFTERNOON HOURS. THE TIME WINDOW FOR PRECIPATION
ACROSS SEMICH IS BETWEEN 20-03Z.

12-21Z...IMPRESSIVE DEPTH OF INFLECTION POINT IN FLOW/TROUGH IN
ADDITION TO THE RELATIVELY CLOSE PROXIMITY YET OF THE SE US
ANTICYCLONE WILL ALLOW FOR A STRONG SURFACE PRESSURE GRADIENT BY
THIS AFTERNOON. SHORTWAVE RIDGE AXIS WILL TAKE UNTIL 15Z OR SO TO
PUSH COMPLETELY THROUGH THE CENTRAL GREAT LAKES. SUSPECT IT WILL
TAKE A GROWING BOUNDARY LAYER AND THIS ADDITIONAL SOUTHWESTERLY
GEOSTROPHIC FLOW COMPONENT AT THE MIDLEVELS TO GET GUSTY
SOUTHWESTERLY FLOW TO REALLY INCREASE AT THE SURFACE. SOUTHWESTERLY
WINDS THIS AFTERNOON ARE EXPECTED TO GUST 30 TO 35 MPH. TEMPERATURES
TODAY ARE EXPECTED TO RISE INTO THE LOWER 40S...HIGHEST IN THE
SAGINAW VALLEY/NORTH OF THE GLACIAL TERRAIN.

21-05Z...THE NARRATIVE OF HIGHER CONFIDENCE FOR PRECIPATION AMOUNTS
REMAINS SOLID (.1 TO .15 OF INCH). ALSO OF HIGHER CONFIDENCE AND
NOTED EARLIER IS THIS EVENT WILL BE GOVERNED BY A VERY FAST SYSTEM
MOTION. THE FAST MOTION WILL NOT ONLY CAUSE A SHORT DURATION OF
PRECIPATION OVERHEAD...BUT IS ALSO SHOWN TO BE A DETRIMENT TO
CHARACTER/STRENGTH OF THE WARM AIR ADVECTION BY THINNING THE THETA E
RIDGE FOR WHICH THE SYSTEM CAN ACT UPON.

THE MAIN FORECAST QUESTION REMAINS CENTERED ON PRECIPITATION TYPE.
THE 29.00Z MODEL SUITE DID NOT OFFER A WHOLE LOT OF CLARITY ON THIS
SUBJECT...PROBABLY BEST SUMMED UP BY THE HUGE DIFFERENCE THAT
REMAINS IN FORECASTED AFTERNOON SURFACE DEWPOINTS PER MET/MAV. THERE
IS A STRONG MODEL CONSENSUS FOR WETBULB COOLING AT PRECIPATION
ONSET. IN FACT...RAW MODEL OUTPUT SHOWS SURFACE TEMPERATURES WARMING
MARGINALLY DURING THE MID TO LATE EVENING AFTER PRECIPATION RATES
DECREASE. CONSENSUS ON MODEL SOUNDINGS IS THAT OF A COLD
PROFILE...WITH LITTLE TO NO WARM SURGE ALOFT. SO...THIS SUGGESTS
PTYPE WILL BE LARGELY DICTATED BY THE DEPTH AND MAGNITUDE OF SURFACE
WARMING TODAY. WITH TEMPS EXPECTED TO REACH THE 40S...SUSPICION AND
GUT FEELING IS THE AREA WILL SEE MUCH MORE LIQUID. HOWEVER...GIVEN
THE THERMAL PROFILE AND THE COLD SFC DEWPONTS CANNOT RULE OUT SNOW
MIXING IN. NOT MUCH OF A CONCERN WITH LITTLE TO NO ACCUMULATION
EXPECTED. THIN NATURE OF THETA E RIDGE THEN SUPPORTS MOISTURE
STRIPPING OUT IN THE MIDLEVELS ALREADY BY 00Z. THUS...CAN VERY WELL
ENVISION A SCENARIO WHERE ICE NUCLEATION BECOMES A PROBLEM AND SEE A
MARKED TRANSITION TO DRIZZLE DURING THE EVENING.

05-12Z...SECONDARY COLD FRONT STRUCTURE SHOWN TO PUSH THROUGH THE
STATE BETWEEN 05-06Z. THE PASSAGE OF THIS FEATURE SHOULD THEN
DECREASE THE POTENTIAL FOR DRIZZLE DURING THE LATTER HALF OF THE
NIGHT DUE TO DRY AIR ADVECTION. SURFACE TEMPERATURES REMAINING ON
THE WARM SIDE OF THE FREEZING MARK WILL LIMIT THE POTENTIAL
FOR RESIDUAL MOISTURE TO FREEZE.

&&

.LONG TERM...

WEAK COLD ADVECTION TRAILING TODAY`S SYSTEM WILL BECOME NEUTRAL
DURING MONDAY MORNING. MODEL SOUNDINGS INDICATE A DEEP BOUNDARY
LAYER GROWING TO NEAR 800 MB BY MID AFTERNOON RESULTING IN NORTHWEST
WIND GUSTING TO AROUND 25 MPH BEFORE THE SURFACE RIDGE ARRIVES LATE
IN THE DAY. THIS...ALONG WITH INCREASING AMOUNTS OF SUNSHINE...WILL
HELP AFTERNOON TEMPS END UP WARMER THAN TODAY WITH HIGHS IN THE MID
TO UPPER 40S OUTSIDE OF THE NORTHERN THUMB.

THE MAIN REASON FOR THE ABBREVIATED COLD ADVECTION MONDAY IS THE
QUICK APPROACH OF THE NEXT RIPPLE OF LOW PRESSURE THROUGH THE PLAINS
AND INTO THE MIDWEST BY MONDAY EVENING. THIS SYSTEM IS DEPICTED IN
THE MODEL DATA AS A SHARD OF UPPER LEVEL ENERGY FROM THE LOW OVER
THE GULF OF ALASKA ROUNDING THE LONG WAVE RIDGE TODAY AND MOVING
THROUGH THE CANADIAN PRAIRIE MONDAY. THE SYSTEM THEN QUICKLY LATCHES
ON TO LOW LEVEL BAROCLINICITY OVER THE NORTHERN PLAINS THAT IS LEFT
OVER FROM TODAY`S SYSTEM. REMNANTS OF THE SURFACE FRONT WILL BE TO
OUR SOUTH BUT THE MID LEVELS OF THE FRONTAL ZONE WILL REMAIN WELL
ORGANIZED OVERHEAD AND TO OUR WEST THROUGH MONDAY. CONSIDERING THE
FAST NORTHWEST FLOW ALOFT...THE WAVE WILL FAVOR A TRACK ALONG THE
700 MB THETA-E GRADIENT. MODEL SOLUTIONS WITH A LOWER AMPLITUDE MID
LEVEL WAVE AND STRONGER FRONTOGENESIS LOOK BEST WHICH LEAVES THE NAM
AS AN OVERDEVELOPED OUTLIER. THE WILDCARD HERE IS THAT THE LOW LEVEL
MOISTURE BROUGHT IN BY TODAY`S SYSTEM IS NEVER REALLY SCOURED OUT
MONDAY AND REMAINS READILY AVAILABLE AT ABOUT 3 G/KG FOR THE SYSTEM
MONDAY NIGHT INTO TUESDAY. THIS EASILY SUPPORTS MODEL QPF IN THE
RANGE OF 0.25 TO 0.5 INCH BUT STILL PUTS THE NAM UNDER SUSPICION FOR
BEING OVERDEVELOPED WITH ITS SURFACE LOW FOLLOWING ITS 850-500 MB
LAYER OMEGA BULLSEYE. LEANING THE FORECAST TOWARD A MORE LIKELY
TRACK FARTHER SOUTH THEN PRESENTS PRIMARILY A RAIN EVENT FOR THE
DETROIT AREA...A RAIN/SNOW MIX FOR THE M-59 TO I-69 CORRIDOR...AND
THEN MOSTLY SNOW FOR THE SAGINAW VALLEY AND NORTHERN THUMB. SINGLE
DIGIT SNOW RATIO WILL BE A LIMITING FACTOR EVEN THAT FAR NORTH...SO
ACCUMULATION WILL BE SET AT A SLOPPY 1-2 INCHES AS A STARTING
POINT.

THE SECOND HALF OF THE WEEK WILL CONSIST OF A TRANSITION IN THE LONG
WAVE PATTERN FROM THE PERSISTENT RIDGE OUT WEST/TROUGH EAST TO MORE
OF ZONAL CONFIGURATION. THIS WILL BE SET OFF BY THE CURRENT GULF OF
ALASKA LOW MOVING INLAND AND REACHING THE NORTHERN PLAINS WEDNESDAY
INTO THURSDAY. THE LARGE SURFACE LOW PRESSURE PATTERN WILL GENERATE
DEEP SOUTHWEST FLOW EAST OF THE MISSISSIPPI AND A WARMING TREND FOR
LOWER MICHIGAN. GUIDANCE TEMPS LOOK GOOD CALLING FOR HIGHS IN THE
60S THURSDAY BEFORE THE COLD FRONT ARRIVES THURSDAY NIGHT INTO
FRIDAY. THIS FRONT WILL BRING TEMPERATURES BACK BELOW NORMAL HEADING
INTO NEXT WEEKEND.

&&

.MARINE...

A GALE WARNING IS IN EFFECT FOR SAGINAW BAY AND CENTRAL LAKE HURON
TODAY AND TONIGHT...AND THROUGH MONDAY AFTERNOON FOR THE NORTH THIRD
OF LAKE HURON. SOUTHWEST GALES WILL DEVELOP AS A LOW PRESSURE SYSTEM
MOVES THROUGH THE NORTHERN GREAT LAKES TODAY. THIS WILL BE FOLLOWED
BY NORTHWEST GALES BEHIND THE ASSOCIATED COLD FRONT OVERNIGHT
THROUGH MONDAY AFTERNOON. THE PRESENCE OF A MODEST AMOUNT OF COLD
AIR IN ADVANCE OF THE LOW...SOME OPEN WATER ON LAKE HURON...AND
FUNNELING IN SAGINAW BAY WILL SUPPORT GALE CONDITIONS. THE SECOND
ROUND OF GALES WILL BE FROM THE NORTHWEST AND WILL BEGIN DURING THE
PREDAWN HOURS MONDAY AND PERSIST THROUGH MIDDAY. TRANQUIL CONDITIONS
WILL TAKE HOLD BENEATH HIGH PRESSURE ON MONDAY NIGHT. THE NEXT LOW
PRESSURE SYSTEM IS DUE IN THE AREA LATE MONDAY NIGHT INTO TUESDAY
BUT WIND SPEED WILL BE LOWER WITH THIS SYSTEM.

&&

.AVIATION...ISSUED 1201 AM EDT SUN MAR 29 2015

VFR CONDITIONS WILL PREVAIL INTO MID SUNDAY AFTERNOON BEFORE AN
APPROACHING TROUGH BRINGS MVFR CIGS AND -SHRA OR -SHRASN BY 20Z TO
22Z OR SO. THIS ACTIVITY LOOKS TO LAST ABOUT 4-6 HOURS AS THIS
FEATURE PASSES THROUGH THE AREA. A STRENGTHENING PRESSURE GRADIENT
WILL ALSO LEAD TO STRONG SOUTHERLY FLOW BY AFTERNOON WITH GUSTS TO
NEAR 30 KNOTS. GENERALLY BREEZY CONDITIONS WILL THEN PERSIST INTO
EARLY EVENING AS WINDS VEER TO SW WITH THE PASSAGE OF THE TROUGH.
MVFR TO LOWER VFR CIGS WILL PERSIST INTO THE NIGHT WITHIN WESTERLY
FLOW BEHIND EXITING SYSTEM.

FOR DTW...VFR UNTIL 21Z-22Z OR SO SUNDAY WHEN MVFR CIGS WITH -SHRA
WILL BECOME INCREASINGLY LIKELY. SOUTHERLY WINDS FROM 190 TO 200
DEGREES WILL ALSO GUST TO 25 KNOTS OR BETTER AT TIMES AFTER 18Z
SUNDAY.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN CEILINGS AOB 5000 FEET AFTER 21Z-22Z SUNDAY.

* MEDIUM IN WIND GUSTS TO 25 KNOTS FROM 190-200 DEGREES BY 18Z-20Z
  SUNDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WARNING FROM NOON TODAY TO MIDNIGHT EDT TONIGHT FOR LHZ363-421-
     422-441-462.

     GALE WARNING FROM NOON TODAY TO 6 PM EDT MONDAY FOR LHZ361-362.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

SHORT TERM...CB
LONG TERM....BT
MARINE.......BT
AVIATION.....CB


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





000
FXUS63 KDTX 290814
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
414 AM EDT SUN MAR 29 2015

.SHORT TERM...TODAY AND TONIGHT

PRECIPITATION ACTIVITY PUSHING ACROSS THE NORTHERN PLAINS THIS
MORNING IS BEING FORCED BY STRONG WARM AIR ADVECTION AHEAD OF THE
VIGOROUS SHORTWAVE OVER WESTERN NODAK/SODAK. THE MAGNITUDE OF
MOISTURE TRANSPORT ON THE NOSE OF A +70 KNOT LOW LEVEL JET WHILE NOT
SURPRISING...IS NOTEWORTHY FOR TIME OF YEAR WITH PWATS OF UP TO .8
OF AN INCH. NWP DATA MAINTAINS THE STRENGTH OF THIS LLJ AXIS DURING
THE DAYLIGHT HOURS TODAY AND FORECASTS THE ARRIVAL OVER LOWER
MICHIGAN DURING THE AFTERNOON HOURS. THE TIME WINDOW FOR PRECIPATION
ACROSS SEMICH IS BETWEEN 20-03Z.

12-21Z...IMPRESSIVE DEPTH OF INFLECTION POINT IN FLOW/TROUGH IN
ADDITION TO THE RELATIVELY CLOSE PROXIMITY YET OF THE SE US
ANTICYCLONE WILL ALLOW FOR A STRONG SURFACE PRESSURE GRADIENT BY
THIS AFTERNOON. SHORTWAVE RIDGE AXIS WILL TAKE UNTIL 15Z OR SO TO
PUSH COMPLETELY THROUGH THE CENTRAL GREAT LAKES. SUSPECT IT WILL
TAKE A GROWING BOUNDARY LAYER AND THIS ADDITIONAL SOUTHWESTERLY
GEOSTROPHIC FLOW COMPONENT AT THE MIDLEVELS TO GET GUSTY
SOUTHWESTERLY FLOW TO REALLY INCREASE AT THE SURFACE. SOUTHWESTERLY
WINDS THIS AFTERNOON ARE EXPECTED TO GUST 30 TO 35 MPH. TEMPERATURES
TODAY ARE EXPECTED TO RISE INTO THE LOWER 40S...HIGHEST IN THE
SAGINAW VALLEY/NORTH OF THE GLACIAL TERRAIN.

21-05Z...THE NARRATIVE OF HIGHER CONFIDENCE FOR PRECIPATION AMOUNTS
REMAINS SOLID (.1 TO .15 OF INCH). ALSO OF HIGHER CONFIDENCE AND
NOTED EARLIER IS THIS EVENT WILL BE GOVERNED BY A VERY FAST SYSTEM
MOTION. THE FAST MOTION WILL NOT ONLY CAUSE A SHORT DURATION OF
PRECIPATION OVERHEAD...BUT IS ALSO SHOWN TO BE A DETRIMENT TO
CHARACTER/STRENGTH OF THE WARM AIR ADVECTION BY THINNING THE THETA E
RIDGE FOR WHICH THE SYSTEM CAN ACT UPON.

THE MAIN FORECAST QUESTION REMAINS CENTERED ON PRECIPITATION TYPE.
THE 29.00Z MODEL SUITE DID NOT OFFER A WHOLE LOT OF CLARITY ON THIS
SUBJECT...PROBABLY BEST SUMMED UP BY THE HUGE DIFFERENCE THAT
REMAINS IN FORECASTED AFTERNOON SURFACE DEWPOINTS PER MET/MAV. THERE
IS A STRONG MODEL CONSENSUS FOR WETBULB COOLING AT PRECIPATION
ONSET. IN FACT...RAW MODEL OUTPUT SHOWS SURFACE TEMPERATURES WARMING
MARGINALLY DURING THE MID TO LATE EVENING AFTER PRECIPATION RATES
DECREASE. CONSENSUS ON MODEL SOUNDINGS IS THAT OF A COLD
PROFILE...WITH LITTLE TO NO WARM SURGE ALOFT. SO...THIS SUGGESTS
PTYPE WILL BE LARGELY DICTATED BY THE DEPTH AND MAGNITUDE OF SURFACE
WARMING TODAY. WITH TEMPS EXPECTED TO REACH THE 40S...SUSPICION AND
GUT FEELING IS THE AREA WILL SEE MUCH MORE LIQUID. HOWEVER...GIVEN
THE THERMAL PROFILE AND THE COLD SFC DEWPONTS CANNOT RULE OUT SNOW
MIXING IN. NOT MUCH OF A CONCERN WITH LITTLE TO NO ACCUMULATION
EXPECTED. THIN NATURE OF THETA E RIDGE THEN SUPPORTS MOISTURE
STRIPPING OUT IN THE MIDLEVELS ALREADY BY 00Z. THUS...CAN VERY WELL
ENVISION A SCENARIO WHERE ICE NUCLEATION BECOMES A PROBLEM AND SEE A
MARKED TRANSITION TO DRIZZLE DURING THE EVENING.

05-12Z...SECONDARY COLD FRONT STRUCTURE SHOWN TO PUSH THROUGH THE
STATE BETWEEN 05-06Z. THE PASSAGE OF THIS FEATURE SHOULD THEN
DECREASE THE POTENTIAL FOR DRIZZLE DURING THE LATTER HALF OF THE
NIGHT DUE TO DRY AIR ADVECTION. SURFACE TEMPERATURES REMAINING ON
THE WARM SIDE OF THE FREEZING MARK WILL LIMIT THE POTENTIAL
FOR RESIDUAL MOISTURE TO FREEZE.

&&

.LONG TERM...

WEAK COLD ADVECTION TRAILING TODAY`S SYSTEM WILL BECOME NEUTRAL
DURING MONDAY MORNING. MODEL SOUNDINGS INDICATE A DEEP BOUNDARY
LAYER GROWING TO NEAR 800 MB BY MID AFTERNOON RESULTING IN NORTHWEST
WIND GUSTING TO AROUND 25 MPH BEFORE THE SURFACE RIDGE ARRIVES LATE
IN THE DAY. THIS...ALONG WITH INCREASING AMOUNTS OF SUNSHINE...WILL
HELP AFTERNOON TEMPS END UP WARMER THAN TODAY WITH HIGHS IN THE MID
TO UPPER 40S OUTSIDE OF THE NORTHERN THUMB.

THE MAIN REASON FOR THE ABBREVIATED COLD ADVECTION MONDAY IS THE
QUICK APPROACH OF THE NEXT RIPPLE OF LOW PRESSURE THROUGH THE PLAINS
AND INTO THE MIDWEST BY MONDAY EVENING. THIS SYSTEM IS DEPICTED IN
THE MODEL DATA AS A SHARD OF UPPER LEVEL ENERGY FROM THE LOW OVER
THE GULF OF ALASKA ROUNDING THE LONG WAVE RIDGE TODAY AND MOVING
THROUGH THE CANADIAN PRAIRIE MONDAY. THE SYSTEM THEN QUICKLY LATCHES
ON TO LOW LEVEL BAROCLINICITY OVER THE NORTHERN PLAINS THAT IS LEFT
OVER FROM TODAY`S SYSTEM. REMNANTS OF THE SURFACE FRONT WILL BE TO
OUR SOUTH BUT THE MID LEVELS OF THE FRONTAL ZONE WILL REMAIN WELL
ORGANIZED OVERHEAD AND TO OUR WEST THROUGH MONDAY. CONSIDERING THE
FAST NORTHWEST FLOW ALOFT...THE WAVE WILL FAVOR A TRACK ALONG THE
700 MB THETA-E GRADIENT. MODEL SOLUTIONS WITH A LOWER AMPLITUDE MID
LEVEL WAVE AND STRONGER FRONTOGENESIS LOOK BEST WHICH LEAVES THE NAM
AS AN OVERDEVELOPED OUTLIER. THE WILDCARD HERE IS THAT THE LOW LEVEL
MOISTURE BROUGHT IN BY TODAY`S SYSTEM IS NEVER REALLY SCOURED OUT
MONDAY AND REMAINS READILY AVAILABLE AT ABOUT 3 G/KG FOR THE SYSTEM
MONDAY NIGHT INTO TUESDAY. THIS EASILY SUPPORTS MODEL QPF IN THE
RANGE OF 0.25 TO 0.5 INCH BUT STILL PUTS THE NAM UNDER SUSPICION FOR
BEING OVERDEVELOPED WITH ITS SURFACE LOW FOLLOWING ITS 850-500 MB
LAYER OMEGA BULLSEYE. LEANING THE FORECAST TOWARD A MORE LIKELY
TRACK FARTHER SOUTH THEN PRESENTS PRIMARILY A RAIN EVENT FOR THE
DETROIT AREA...A RAIN/SNOW MIX FOR THE M-59 TO I-69 CORRIDOR...AND
THEN MOSTLY SNOW FOR THE SAGINAW VALLEY AND NORTHERN THUMB. SINGLE
DIGIT SNOW RATIO WILL BE A LIMITING FACTOR EVEN THAT FAR NORTH...SO
ACCUMULATION WILL BE SET AT A SLOPPY 1-2 INCHES AS A STARTING
POINT.

THE SECOND HALF OF THE WEEK WILL CONSIST OF A TRANSITION IN THE LONG
WAVE PATTERN FROM THE PERSISTENT RIDGE OUT WEST/TROUGH EAST TO MORE
OF ZONAL CONFIGURATION. THIS WILL BE SET OFF BY THE CURRENT GULF OF
ALASKA LOW MOVING INLAND AND REACHING THE NORTHERN PLAINS WEDNESDAY
INTO THURSDAY. THE LARGE SURFACE LOW PRESSURE PATTERN WILL GENERATE
DEEP SOUTHWEST FLOW EAST OF THE MISSISSIPPI AND A WARMING TREND FOR
LOWER MICHIGAN. GUIDANCE TEMPS LOOK GOOD CALLING FOR HIGHS IN THE
60S THURSDAY BEFORE THE COLD FRONT ARRIVES THURSDAY NIGHT INTO
FRIDAY. THIS FRONT WILL BRING TEMPERATURES BACK BELOW NORMAL HEADING
INTO NEXT WEEKEND.

&&

.MARINE...

A GALE WARNING IS IN EFFECT FOR SAGINAW BAY AND CENTRAL LAKE HURON
TODAY AND TONIGHT...AND THROUGH MONDAY AFTERNOON FOR THE NORTH THIRD
OF LAKE HURON. SOUTHWEST GALES WILL DEVELOP AS A LOW PRESSURE SYSTEM
MOVES THROUGH THE NORTHERN GREAT LAKES TODAY. THIS WILL BE FOLLOWED
BY NORTHWEST GALES BEHIND THE ASSOCIATED COLD FRONT OVERNIGHT
THROUGH MONDAY AFTERNOON. THE PRESENCE OF A MODEST AMOUNT OF COLD
AIR IN ADVANCE OF THE LOW...SOME OPEN WATER ON LAKE HURON...AND
FUNNELING IN SAGINAW BAY WILL SUPPORT GALE CONDITIONS. THE SECOND
ROUND OF GALES WILL BE FROM THE NORTHWEST AND WILL BEGIN DURING THE
PREDAWN HOURS MONDAY AND PERSIST THROUGH MIDDAY. TRANQUIL CONDITIONS
WILL TAKE HOLD BENEATH HIGH PRESSURE ON MONDAY NIGHT. THE NEXT LOW
PRESSURE SYSTEM IS DUE IN THE AREA LATE MONDAY NIGHT INTO TUESDAY
BUT WIND SPEED WILL BE LOWER WITH THIS SYSTEM.

&&

.AVIATION...ISSUED 1201 AM EDT SUN MAR 29 2015

VFR CONDITIONS WILL PREVAIL INTO MID SUNDAY AFTERNOON BEFORE AN
APPROACHING TROUGH BRINGS MVFR CIGS AND -SHRA OR -SHRASN BY 20Z TO
22Z OR SO. THIS ACTIVITY LOOKS TO LAST ABOUT 4-6 HOURS AS THIS
FEATURE PASSES THROUGH THE AREA. A STRENGTHENING PRESSURE GRADIENT
WILL ALSO LEAD TO STRONG SOUTHERLY FLOW BY AFTERNOON WITH GUSTS TO
NEAR 30 KNOTS. GENERALLY BREEZY CONDITIONS WILL THEN PERSIST INTO
EARLY EVENING AS WINDS VEER TO SW WITH THE PASSAGE OF THE TROUGH.
MVFR TO LOWER VFR CIGS WILL PERSIST INTO THE NIGHT WITHIN WESTERLY
FLOW BEHIND EXITING SYSTEM.

FOR DTW...VFR UNTIL 21Z-22Z OR SO SUNDAY WHEN MVFR CIGS WITH -SHRA
WILL BECOME INCREASINGLY LIKELY. SOUTHERLY WINDS FROM 190 TO 200
DEGREES WILL ALSO GUST TO 25 KNOTS OR BETTER AT TIMES AFTER 18Z
SUNDAY.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN CEILINGS AOB 5000 FEET AFTER 21Z-22Z SUNDAY.

* MEDIUM IN WIND GUSTS TO 25 KNOTS FROM 190-200 DEGREES BY 18Z-20Z
  SUNDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WARNING FROM NOON TODAY TO MIDNIGHT EDT TONIGHT FOR LHZ363-421-
     422-441-462.

     GALE WARNING FROM NOON TODAY TO 6 PM EDT MONDAY FOR LHZ361-362.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

SHORT TERM...CB
LONG TERM....BT
MARINE.......BT
AVIATION.....CB


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




000
FXUS63 KDTX 290814
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
414 AM EDT SUN MAR 29 2015

.SHORT TERM...TODAY AND TONIGHT

PRECIPITATION ACTIVITY PUSHING ACROSS THE NORTHERN PLAINS THIS
MORNING IS BEING FORCED BY STRONG WARM AIR ADVECTION AHEAD OF THE
VIGOROUS SHORTWAVE OVER WESTERN NODAK/SODAK. THE MAGNITUDE OF
MOISTURE TRANSPORT ON THE NOSE OF A +70 KNOT LOW LEVEL JET WHILE NOT
SURPRISING...IS NOTEWORTHY FOR TIME OF YEAR WITH PWATS OF UP TO .8
OF AN INCH. NWP DATA MAINTAINS THE STRENGTH OF THIS LLJ AXIS DURING
THE DAYLIGHT HOURS TODAY AND FORECASTS THE ARRIVAL OVER LOWER
MICHIGAN DURING THE AFTERNOON HOURS. THE TIME WINDOW FOR PRECIPATION
ACROSS SEMICH IS BETWEEN 20-03Z.

12-21Z...IMPRESSIVE DEPTH OF INFLECTION POINT IN FLOW/TROUGH IN
ADDITION TO THE RELATIVELY CLOSE PROXIMITY YET OF THE SE US
ANTICYCLONE WILL ALLOW FOR A STRONG SURFACE PRESSURE GRADIENT BY
THIS AFTERNOON. SHORTWAVE RIDGE AXIS WILL TAKE UNTIL 15Z OR SO TO
PUSH COMPLETELY THROUGH THE CENTRAL GREAT LAKES. SUSPECT IT WILL
TAKE A GROWING BOUNDARY LAYER AND THIS ADDITIONAL SOUTHWESTERLY
GEOSTROPHIC FLOW COMPONENT AT THE MIDLEVELS TO GET GUSTY
SOUTHWESTERLY FLOW TO REALLY INCREASE AT THE SURFACE. SOUTHWESTERLY
WINDS THIS AFTERNOON ARE EXPECTED TO GUST 30 TO 35 MPH. TEMPERATURES
TODAY ARE EXPECTED TO RISE INTO THE LOWER 40S...HIGHEST IN THE
SAGINAW VALLEY/NORTH OF THE GLACIAL TERRAIN.

21-05Z...THE NARRATIVE OF HIGHER CONFIDENCE FOR PRECIPATION AMOUNTS
REMAINS SOLID (.1 TO .15 OF INCH). ALSO OF HIGHER CONFIDENCE AND
NOTED EARLIER IS THIS EVENT WILL BE GOVERNED BY A VERY FAST SYSTEM
MOTION. THE FAST MOTION WILL NOT ONLY CAUSE A SHORT DURATION OF
PRECIPATION OVERHEAD...BUT IS ALSO SHOWN TO BE A DETRIMENT TO
CHARACTER/STRENGTH OF THE WARM AIR ADVECTION BY THINNING THE THETA E
RIDGE FOR WHICH THE SYSTEM CAN ACT UPON.

THE MAIN FORECAST QUESTION REMAINS CENTERED ON PRECIPITATION TYPE.
THE 29.00Z MODEL SUITE DID NOT OFFER A WHOLE LOT OF CLARITY ON THIS
SUBJECT...PROBABLY BEST SUMMED UP BY THE HUGE DIFFERENCE THAT
REMAINS IN FORECASTED AFTERNOON SURFACE DEWPOINTS PER MET/MAV. THERE
IS A STRONG MODEL CONSENSUS FOR WETBULB COOLING AT PRECIPATION
ONSET. IN FACT...RAW MODEL OUTPUT SHOWS SURFACE TEMPERATURES WARMING
MARGINALLY DURING THE MID TO LATE EVENING AFTER PRECIPATION RATES
DECREASE. CONSENSUS ON MODEL SOUNDINGS IS THAT OF A COLD
PROFILE...WITH LITTLE TO NO WARM SURGE ALOFT. SO...THIS SUGGESTS
PTYPE WILL BE LARGELY DICTATED BY THE DEPTH AND MAGNITUDE OF SURFACE
WARMING TODAY. WITH TEMPS EXPECTED TO REACH THE 40S...SUSPICION AND
GUT FEELING IS THE AREA WILL SEE MUCH MORE LIQUID. HOWEVER...GIVEN
THE THERMAL PROFILE AND THE COLD SFC DEWPONTS CANNOT RULE OUT SNOW
MIXING IN. NOT MUCH OF A CONCERN WITH LITTLE TO NO ACCUMULATION
EXPECTED. THIN NATURE OF THETA E RIDGE THEN SUPPORTS MOISTURE
STRIPPING OUT IN THE MIDLEVELS ALREADY BY 00Z. THUS...CAN VERY WELL
ENVISION A SCENARIO WHERE ICE NUCLEATION BECOMES A PROBLEM AND SEE A
MARKED TRANSITION TO DRIZZLE DURING THE EVENING.

05-12Z...SECONDARY COLD FRONT STRUCTURE SHOWN TO PUSH THROUGH THE
STATE BETWEEN 05-06Z. THE PASSAGE OF THIS FEATURE SHOULD THEN
DECREASE THE POTENTIAL FOR DRIZZLE DURING THE LATTER HALF OF THE
NIGHT DUE TO DRY AIR ADVECTION. SURFACE TEMPERATURES REMAINING ON
THE WARM SIDE OF THE FREEZING MARK WILL LIMIT THE POTENTIAL
FOR RESIDUAL MOISTURE TO FREEZE.

&&

.LONG TERM...

WEAK COLD ADVECTION TRAILING TODAY`S SYSTEM WILL BECOME NEUTRAL
DURING MONDAY MORNING. MODEL SOUNDINGS INDICATE A DEEP BOUNDARY
LAYER GROWING TO NEAR 800 MB BY MID AFTERNOON RESULTING IN NORTHWEST
WIND GUSTING TO AROUND 25 MPH BEFORE THE SURFACE RIDGE ARRIVES LATE
IN THE DAY. THIS...ALONG WITH INCREASING AMOUNTS OF SUNSHINE...WILL
HELP AFTERNOON TEMPS END UP WARMER THAN TODAY WITH HIGHS IN THE MID
TO UPPER 40S OUTSIDE OF THE NORTHERN THUMB.

THE MAIN REASON FOR THE ABBREVIATED COLD ADVECTION MONDAY IS THE
QUICK APPROACH OF THE NEXT RIPPLE OF LOW PRESSURE THROUGH THE PLAINS
AND INTO THE MIDWEST BY MONDAY EVENING. THIS SYSTEM IS DEPICTED IN
THE MODEL DATA AS A SHARD OF UPPER LEVEL ENERGY FROM THE LOW OVER
THE GULF OF ALASKA ROUNDING THE LONG WAVE RIDGE TODAY AND MOVING
THROUGH THE CANADIAN PRAIRIE MONDAY. THE SYSTEM THEN QUICKLY LATCHES
ON TO LOW LEVEL BAROCLINICITY OVER THE NORTHERN PLAINS THAT IS LEFT
OVER FROM TODAY`S SYSTEM. REMNANTS OF THE SURFACE FRONT WILL BE TO
OUR SOUTH BUT THE MID LEVELS OF THE FRONTAL ZONE WILL REMAIN WELL
ORGANIZED OVERHEAD AND TO OUR WEST THROUGH MONDAY. CONSIDERING THE
FAST NORTHWEST FLOW ALOFT...THE WAVE WILL FAVOR A TRACK ALONG THE
700 MB THETA-E GRADIENT. MODEL SOLUTIONS WITH A LOWER AMPLITUDE MID
LEVEL WAVE AND STRONGER FRONTOGENESIS LOOK BEST WHICH LEAVES THE NAM
AS AN OVERDEVELOPED OUTLIER. THE WILDCARD HERE IS THAT THE LOW LEVEL
MOISTURE BROUGHT IN BY TODAY`S SYSTEM IS NEVER REALLY SCOURED OUT
MONDAY AND REMAINS READILY AVAILABLE AT ABOUT 3 G/KG FOR THE SYSTEM
MONDAY NIGHT INTO TUESDAY. THIS EASILY SUPPORTS MODEL QPF IN THE
RANGE OF 0.25 TO 0.5 INCH BUT STILL PUTS THE NAM UNDER SUSPICION FOR
BEING OVERDEVELOPED WITH ITS SURFACE LOW FOLLOWING ITS 850-500 MB
LAYER OMEGA BULLSEYE. LEANING THE FORECAST TOWARD A MORE LIKELY
TRACK FARTHER SOUTH THEN PRESENTS PRIMARILY A RAIN EVENT FOR THE
DETROIT AREA...A RAIN/SNOW MIX FOR THE M-59 TO I-69 CORRIDOR...AND
THEN MOSTLY SNOW FOR THE SAGINAW VALLEY AND NORTHERN THUMB. SINGLE
DIGIT SNOW RATIO WILL BE A LIMITING FACTOR EVEN THAT FAR NORTH...SO
ACCUMULATION WILL BE SET AT A SLOPPY 1-2 INCHES AS A STARTING
POINT.

THE SECOND HALF OF THE WEEK WILL CONSIST OF A TRANSITION IN THE LONG
WAVE PATTERN FROM THE PERSISTENT RIDGE OUT WEST/TROUGH EAST TO MORE
OF ZONAL CONFIGURATION. THIS WILL BE SET OFF BY THE CURRENT GULF OF
ALASKA LOW MOVING INLAND AND REACHING THE NORTHERN PLAINS WEDNESDAY
INTO THURSDAY. THE LARGE SURFACE LOW PRESSURE PATTERN WILL GENERATE
DEEP SOUTHWEST FLOW EAST OF THE MISSISSIPPI AND A WARMING TREND FOR
LOWER MICHIGAN. GUIDANCE TEMPS LOOK GOOD CALLING FOR HIGHS IN THE
60S THURSDAY BEFORE THE COLD FRONT ARRIVES THURSDAY NIGHT INTO
FRIDAY. THIS FRONT WILL BRING TEMPERATURES BACK BELOW NORMAL HEADING
INTO NEXT WEEKEND.

&&

.MARINE...

A GALE WARNING IS IN EFFECT FOR SAGINAW BAY AND CENTRAL LAKE HURON
TODAY AND TONIGHT...AND THROUGH MONDAY AFTERNOON FOR THE NORTH THIRD
OF LAKE HURON. SOUTHWEST GALES WILL DEVELOP AS A LOW PRESSURE SYSTEM
MOVES THROUGH THE NORTHERN GREAT LAKES TODAY. THIS WILL BE FOLLOWED
BY NORTHWEST GALES BEHIND THE ASSOCIATED COLD FRONT OVERNIGHT
THROUGH MONDAY AFTERNOON. THE PRESENCE OF A MODEST AMOUNT OF COLD
AIR IN ADVANCE OF THE LOW...SOME OPEN WATER ON LAKE HURON...AND
FUNNELING IN SAGINAW BAY WILL SUPPORT GALE CONDITIONS. THE SECOND
ROUND OF GALES WILL BE FROM THE NORTHWEST AND WILL BEGIN DURING THE
PREDAWN HOURS MONDAY AND PERSIST THROUGH MIDDAY. TRANQUIL CONDITIONS
WILL TAKE HOLD BENEATH HIGH PRESSURE ON MONDAY NIGHT. THE NEXT LOW
PRESSURE SYSTEM IS DUE IN THE AREA LATE MONDAY NIGHT INTO TUESDAY
BUT WIND SPEED WILL BE LOWER WITH THIS SYSTEM.

&&

.AVIATION...ISSUED 1201 AM EDT SUN MAR 29 2015

VFR CONDITIONS WILL PREVAIL INTO MID SUNDAY AFTERNOON BEFORE AN
APPROACHING TROUGH BRINGS MVFR CIGS AND -SHRA OR -SHRASN BY 20Z TO
22Z OR SO. THIS ACTIVITY LOOKS TO LAST ABOUT 4-6 HOURS AS THIS
FEATURE PASSES THROUGH THE AREA. A STRENGTHENING PRESSURE GRADIENT
WILL ALSO LEAD TO STRONG SOUTHERLY FLOW BY AFTERNOON WITH GUSTS TO
NEAR 30 KNOTS. GENERALLY BREEZY CONDITIONS WILL THEN PERSIST INTO
EARLY EVENING AS WINDS VEER TO SW WITH THE PASSAGE OF THE TROUGH.
MVFR TO LOWER VFR CIGS WILL PERSIST INTO THE NIGHT WITHIN WESTERLY
FLOW BEHIND EXITING SYSTEM.

FOR DTW...VFR UNTIL 21Z-22Z OR SO SUNDAY WHEN MVFR CIGS WITH -SHRA
WILL BECOME INCREASINGLY LIKELY. SOUTHERLY WINDS FROM 190 TO 200
DEGREES WILL ALSO GUST TO 25 KNOTS OR BETTER AT TIMES AFTER 18Z
SUNDAY.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN CEILINGS AOB 5000 FEET AFTER 21Z-22Z SUNDAY.

* MEDIUM IN WIND GUSTS TO 25 KNOTS FROM 190-200 DEGREES BY 18Z-20Z
  SUNDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WARNING FROM NOON TODAY TO MIDNIGHT EDT TONIGHT FOR LHZ363-421-
     422-441-462.

     GALE WARNING FROM NOON TODAY TO 6 PM EDT MONDAY FOR LHZ361-362.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

SHORT TERM...CB
LONG TERM....BT
MARINE.......BT
AVIATION.....CB


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




000
FXUS63 KDTX 290401
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1201 AM EDT SUN MAR 29 2015


.AVIATION...

VFR CONDITIONS WILL PREVAIL INTO MID SUNDAY AFTERNOON BEFORE AN
APPROACHING TROUGH BRINGS MVFR CIGS AND -SHRA OR -SHRASN BY 20Z TO
22Z OR SO. THIS ACTIVITY LOOKS TO LAST ABOUT 4-6 HOURS AS THIS
FEATURE PASSES THROUGH THE AREA. A STRENGTHENING PRESSURE GRADIENT
WILL ALSO LEAD TO STRONG SOUTHERLY FLOW BY AFTERNOON WITH GUSTS TO
NEAR 30 KNOTS. GENERALLY BREEZY CONDITIONS WILL THEN PERSIST INTO
EARLY EVENING AS WINDS VEER TO SW WITH THE PASSAGE OF THE TROUGH.
MVFR TO LOWER VFR CIGS WILL PERSIST INTO THE NIGHT WITHIN WESTERLY
FLOW BEHIND EXITING SYSTEM.

FOR DTW...VFR UNTIL 21Z-22Z OR SO SUNDAY WHEN MVFR CIGS WITH -SHRA
WILL BECOME INCREASINGLY LIKELY. SOUTHERLY WINDS FROM 190 TO 200
DEGREES WILL ALSO GUST TO 25 KNOTS OR BETTER AT TIMES AFTER 18Z
SUNDAY.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN CEILINGS AOB 5000 FEET AFTER 21Z-22Z SUNDAY.

* MEDIUM IN WIND GUSTS TO 25 KNOTS FROM 190-200 DEGREES BY 18Z-20Z
  SUNDAY.

&&

.PREV DISCUSSION...ISSUED 338 PM EDT SAT MAR 28 2015

SHORT TERM...THROUGH TONIGHT

WATER VAPOR IMAGERY SHOWS UPPER RIDGING BEGINNING TO CASCADE DOWN
ACROSS MICHIGAN. THIS WILL PROVIDE DRY WEATHER...MOSTLY CLEAR
SKIES...AND FAIRLY LIGHT WINDS TONIGHT AS SURFACE HIGH PRESSURE
BECOMES CENTERED OVER THE OHIO VALLEY. GOOD RADIATIONAL COOLING
CONDITIONS WILL SET UP FOR MOST OF THE NIGHT...INHIBITED ONLY LATE
AS HIGH CLOUDS ARRIVE...AS THE UPPER WAVE NOW PASSING THROUGH THE
NORTHERN ROCKIES APPROACHES THE GREAT LAKES. WARMER AIR WILL BEGIN
TO ADVECT INTO THE AREA TONIGHT AHEAD OF THIS WAVE...HOWEVER IT WILL
BE OFFSET BY RADIATIONAL COOLING. THIS WILL KEEP MIN TEMPERATURES
TONIGHT CLOSE TO MINS EXPERIENCED THIS MORNING...WELL BELOW NORMAL
IN THE TEENS.

LONG TERM...

LEE CYCLONE IN SOUTHERN SASKATCHEWAN IS CHUGGING EAST IN RESPONSE TO
HEIGHT FALLS OWING TO THE COMPACT MID-LEVEL CIRCULATION OVER THE
NORTHERN INTERMOUNTAIN WEST. THE ASSOCIATED PV ANOMALY WILL
TRANSLATE EAST WITHIN PROGRESSIVE MEAN FLOW WHILE ADDITIONAL ENERGY
OVER CENTRAL CANADA WRAPS INTO THE AMPLIFYING TROUGH. IN SOUTHEAST
MICHIGAN, THIS WILL MANIFEST AS A QUICK 1-2 PUNCH OF UPPER FORCING
WITH THE LEAD WAVE BEING STEERED ACROSS NORTHERN LAKE HURON EARLY
SUNDAY EVENING WHILE TRAILING WAVE ACTS ON RESIDUAL LOW-LEVEL
MOISTURE WITHIN A COOLING COLUMN BEGINNING LATE SUNDAY EVENING.

A STRONG 60KT LOW-LEVEL JET IS FORECAST TO DEVELOP OVER THE NORTHERN
GREAT PLAINS TONIGHT IN ADVANCE OF THE LEAD WAVE. THE LLJ IS
EXPECTED TO MAINTAIN ITS STRENGTH, AND PERHAPS EVEN BROADEN ITS
SPATIAL FOOTPRINT, BY THE TIME IT REACHES SEMI SUNDAY AFTERNOON.
FAST SYSTEM SPEED WILL LIMIT MOISTURE TRANSPORT (PWATS AROUND 0.5"),
BUT FORCING ALONG THE LEAD EDGE AND WITHIN THE STRONG MOISTURE
TRANSPORT AXIS WILL BE SUFFICIENT TO PRODUCE A BAND OF LIGHT TO
MODERATE SHOWERS MOVING W-E ACROSS THE CWA 19 THROUGH 00Z. THE
STRENGTHENING WIND FIELD WILL SUPPORT WIND GUSTS OF 25 KNOTS
AREAWIDE...POTENTIALLY 30 KNOTS IN THE SAGINAW VALLEY. THIS WILL
EASILY DRIVE TEMPERATURES INTO THE 40S PRIOR TO THE ARRIVAL OF
PRECIPITATION. MODELS CONTINUE TO WET-BULB THE COLUMN TO FREEZING AS
SHOWERS ASSOCIATED WITH THE RESIDENT LLJ TRACK INTO THE AREA,
SUPPORTING A CHANGEOVER TO ALL SNOW. HOWEVER, SUSPECT THAT THE
RELATIVELY LIGHT QPF/STRONG WAA SCENARIO MAY NOT BE IDEALLY HANDLED
AT THE GRID SCALE STILL PREFER TO LEAN TOWARD RAIN.

FORCING ASSOCIATED WITH THE TRAILING WAVE WILL BEGIN SPREADING
ACROSS LOWER MI BY 00Z. DESPITE DRY AIR WRAPPING INTO THE COLUMN
ABOVE 700MB, SUFFICIENT LOW-LEVEL MOISTURE WILL BE IN PLACE IN
ADVANCE OF THE COLD FRONT TO SUPPORT SCATTERED RAIN/SNOW SHOWERS
DURING THE EVENING. LIGHT RATES AND A WARM/WET GROUND SHOULD PREVENT
ANY ACCUMULATION.

BREEZY CONDITIONS WILL PERSIST SUNDAY NIGHT THROUGH MONDAY AFTERNOON
AS COLD ADVECTION INCREASES OVERNIGHT. GUSTS OF 15 TO 20 KNOTS WILL
PERSIST IN SPITE OF NOCTURNAL STABILIZATION COURTESY OF ONGOING
ISENTROPIC DESCENT. 850MB TEMPERATURES ARE FORECAST TO FALL TO -4 TO
-7C BY MONDAY MORNING. 12Z NAM INDICATES A VERY WELL-MIXED
ENVIRONMENT DEVELOPING LATE MONDAY MORNING INTO THE AFTERNOON AS
LAPSE RATES APPROXIMATE TO DRY ADIABATIC UP TO 800MB. MOMENTUM LOOKS
RATHER UNIFORMLY DISTRIBUTED THROUGH THE LAYER AND WILL BE
SUPPORTIVE OF GUSTINESS TO THE TUNE OF AROUND 20 KNOTS. DEEP MIXING
WILL ALSO SUPPORT A HIGH BASED STRATOCU DECK BY AFTERNOON,
ESPECIALLY ACROSS THE NORTH AS ANOTHER QUICK-MOVING EMBEDDED WAVE
ZIPS BY DURING THE DAY. NO ARGUMENTS FROM THE CONSENSUS WHICH OFFERS
HIGHS SOLIDLY IN THE MID 40S / LOW 40S IN THE THUMB.

BUILDING HIGH PRESSURE WILL EASE THE GRADIENT BY MONDAY EVENING
ALLOWING WINDS TO SLACKEN AS THE SUN SETS. ISENTROPIC ASCENT WILL
THEN INCREASE OVERNIGHT IN ADVANCE OF A FAST-MOVING SHEAR MAX WITH
ORIGINS OVER THE NORTHEAST PACIFIC. THIS WAVE WILL BRING A BRIEF
RAIN OR RAIN/SNOW MIX LATE MONDAY NIGHT. PREDICTABILITY REMAINS LOW,
BUT A LIGHT ACCUMULATION OF AN INCH OR SO WILL BE POSSIBLE OVER A
PORTION OF THE CWA DEPENDING ON THE EXACT EVOLUTION OF THE LOW-LEVEL
THERMODYNAMIC PROFILE.

THE CLIPPER SYSTEM WILL QUICKLY BE MOVING OFF THE THE EAST DURING
THE DAY ON TUESDAY. WARMING TEMPERATURES THROUGHOUT THE DAY WILL
ALLOW ANY FROZEN AND MIXED PRECIPITATION TO CHANGE OVER ENTIRELY TO
RAIN BY MID TUESDAY MORNING. WARMER TEMPERATURES AND DRY CONDITIONS
RETURN ON WEDNESDAY AND LAST INTO THURSDAY. HIGHS ON WEDNESDAY WILL
BE IN THE LOW 50S WITH HIGHS ON THURSDAY POTENTIALLY REACHING INTO
THE LOW 60S. THE NEXT LOW PRESSURE SYSTEM WILL TRACK ACROSS THE
NORTHERN GREAT LAKES DRAGGING A COLD FRONT ACROSS LOWER MICHIGAN ON
THURSDAY EVENING. THIS SYSTEM WILL BRING THE NEXT CHANCE OF RAIN
SHOWERS TO SOUTHEAST MICHIGAN...POSSIBLY LASTING THROUGH SATURDAY AS
A SERIES OF WEAK LOW PRESSURE SYSTEMS FOLLOW IN THE WAKE OF THIS
LARGER SYSTEM.

MARINE...

LIGHT SOUTHWEST WINDS TONIGHT WILL BECOME STRONG BY MIDDAY SUNDAY
AND WILL BE SUSTAINED AT NEAR-GALES OVER CENTRAL LAKE HURON BY
SUNDAY AFTERNOON. THE PRESENCE OF A MODEST AMOUNT OF COLD AIR AND
SOME OPEN WATER...AND PERHAPS EVEN SOME FUNNELING IN SAGINAW
BAY...ARE ENOUGH TO WARRANT THE ISSUANCE OF A GALE WATCH FOR SOUTH-
SOUTHWEST GALES SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR MUCH OF
LAKE HURON. WINDS WILL THEN SUBSIDE SOMEWHAT BY MIDNIGHT SUNDAY
NIGHT AND A REPRIEVE OF ABOUT 6 HOURS IS EXPECTED BEFORE NORTHWEST
GALES DEVELOP BEHIND A PASSING COLD FRONT. THIS SECOND ROUND OF
GALES WILL BE FROM THE NORTHWEST AND WILL BEGIN DURING THE PREDAWN
HOURS MONDAY AND PERSIST THROUGH MIDDAY. TRANQUIL CONDITIONS WILL
TAKE HOLD BENEATH HIGH PRESSURE ON MONDAY NIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM THIS AFTERNOON THROUGH THIS EVENING FOR LHZ362-363-
     421-422-441-462-463.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....CB
SHORT TERM...HLO
LONG TERM....JVC/RK
MARINE.......JVC


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




000
FXUS63 KDTX 290401
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1201 AM EDT SUN MAR 29 2015


.AVIATION...

VFR CONDITIONS WILL PREVAIL INTO MID SUNDAY AFTERNOON BEFORE AN
APPROACHING TROUGH BRINGS MVFR CIGS AND -SHRA OR -SHRASN BY 20Z TO
22Z OR SO. THIS ACTIVITY LOOKS TO LAST ABOUT 4-6 HOURS AS THIS
FEATURE PASSES THROUGH THE AREA. A STRENGTHENING PRESSURE GRADIENT
WILL ALSO LEAD TO STRONG SOUTHERLY FLOW BY AFTERNOON WITH GUSTS TO
NEAR 30 KNOTS. GENERALLY BREEZY CONDITIONS WILL THEN PERSIST INTO
EARLY EVENING AS WINDS VEER TO SW WITH THE PASSAGE OF THE TROUGH.
MVFR TO LOWER VFR CIGS WILL PERSIST INTO THE NIGHT WITHIN WESTERLY
FLOW BEHIND EXITING SYSTEM.

FOR DTW...VFR UNTIL 21Z-22Z OR SO SUNDAY WHEN MVFR CIGS WITH -SHRA
WILL BECOME INCREASINGLY LIKELY. SOUTHERLY WINDS FROM 190 TO 200
DEGREES WILL ALSO GUST TO 25 KNOTS OR BETTER AT TIMES AFTER 18Z
SUNDAY.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN CEILINGS AOB 5000 FEET AFTER 21Z-22Z SUNDAY.

* MEDIUM IN WIND GUSTS TO 25 KNOTS FROM 190-200 DEGREES BY 18Z-20Z
  SUNDAY.

&&

.PREV DISCUSSION...ISSUED 338 PM EDT SAT MAR 28 2015

SHORT TERM...THROUGH TONIGHT

WATER VAPOR IMAGERY SHOWS UPPER RIDGING BEGINNING TO CASCADE DOWN
ACROSS MICHIGAN. THIS WILL PROVIDE DRY WEATHER...MOSTLY CLEAR
SKIES...AND FAIRLY LIGHT WINDS TONIGHT AS SURFACE HIGH PRESSURE
BECOMES CENTERED OVER THE OHIO VALLEY. GOOD RADIATIONAL COOLING
CONDITIONS WILL SET UP FOR MOST OF THE NIGHT...INHIBITED ONLY LATE
AS HIGH CLOUDS ARRIVE...AS THE UPPER WAVE NOW PASSING THROUGH THE
NORTHERN ROCKIES APPROACHES THE GREAT LAKES. WARMER AIR WILL BEGIN
TO ADVECT INTO THE AREA TONIGHT AHEAD OF THIS WAVE...HOWEVER IT WILL
BE OFFSET BY RADIATIONAL COOLING. THIS WILL KEEP MIN TEMPERATURES
TONIGHT CLOSE TO MINS EXPERIENCED THIS MORNING...WELL BELOW NORMAL
IN THE TEENS.

LONG TERM...

LEE CYCLONE IN SOUTHERN SASKATCHEWAN IS CHUGGING EAST IN RESPONSE TO
HEIGHT FALLS OWING TO THE COMPACT MID-LEVEL CIRCULATION OVER THE
NORTHERN INTERMOUNTAIN WEST. THE ASSOCIATED PV ANOMALY WILL
TRANSLATE EAST WITHIN PROGRESSIVE MEAN FLOW WHILE ADDITIONAL ENERGY
OVER CENTRAL CANADA WRAPS INTO THE AMPLIFYING TROUGH. IN SOUTHEAST
MICHIGAN, THIS WILL MANIFEST AS A QUICK 1-2 PUNCH OF UPPER FORCING
WITH THE LEAD WAVE BEING STEERED ACROSS NORTHERN LAKE HURON EARLY
SUNDAY EVENING WHILE TRAILING WAVE ACTS ON RESIDUAL LOW-LEVEL
MOISTURE WITHIN A COOLING COLUMN BEGINNING LATE SUNDAY EVENING.

A STRONG 60KT LOW-LEVEL JET IS FORECAST TO DEVELOP OVER THE NORTHERN
GREAT PLAINS TONIGHT IN ADVANCE OF THE LEAD WAVE. THE LLJ IS
EXPECTED TO MAINTAIN ITS STRENGTH, AND PERHAPS EVEN BROADEN ITS
SPATIAL FOOTPRINT, BY THE TIME IT REACHES SEMI SUNDAY AFTERNOON.
FAST SYSTEM SPEED WILL LIMIT MOISTURE TRANSPORT (PWATS AROUND 0.5"),
BUT FORCING ALONG THE LEAD EDGE AND WITHIN THE STRONG MOISTURE
TRANSPORT AXIS WILL BE SUFFICIENT TO PRODUCE A BAND OF LIGHT TO
MODERATE SHOWERS MOVING W-E ACROSS THE CWA 19 THROUGH 00Z. THE
STRENGTHENING WIND FIELD WILL SUPPORT WIND GUSTS OF 25 KNOTS
AREAWIDE...POTENTIALLY 30 KNOTS IN THE SAGINAW VALLEY. THIS WILL
EASILY DRIVE TEMPERATURES INTO THE 40S PRIOR TO THE ARRIVAL OF
PRECIPITATION. MODELS CONTINUE TO WET-BULB THE COLUMN TO FREEZING AS
SHOWERS ASSOCIATED WITH THE RESIDENT LLJ TRACK INTO THE AREA,
SUPPORTING A CHANGEOVER TO ALL SNOW. HOWEVER, SUSPECT THAT THE
RELATIVELY LIGHT QPF/STRONG WAA SCENARIO MAY NOT BE IDEALLY HANDLED
AT THE GRID SCALE STILL PREFER TO LEAN TOWARD RAIN.

FORCING ASSOCIATED WITH THE TRAILING WAVE WILL BEGIN SPREADING
ACROSS LOWER MI BY 00Z. DESPITE DRY AIR WRAPPING INTO THE COLUMN
ABOVE 700MB, SUFFICIENT LOW-LEVEL MOISTURE WILL BE IN PLACE IN
ADVANCE OF THE COLD FRONT TO SUPPORT SCATTERED RAIN/SNOW SHOWERS
DURING THE EVENING. LIGHT RATES AND A WARM/WET GROUND SHOULD PREVENT
ANY ACCUMULATION.

BREEZY CONDITIONS WILL PERSIST SUNDAY NIGHT THROUGH MONDAY AFTERNOON
AS COLD ADVECTION INCREASES OVERNIGHT. GUSTS OF 15 TO 20 KNOTS WILL
PERSIST IN SPITE OF NOCTURNAL STABILIZATION COURTESY OF ONGOING
ISENTROPIC DESCENT. 850MB TEMPERATURES ARE FORECAST TO FALL TO -4 TO
-7C BY MONDAY MORNING. 12Z NAM INDICATES A VERY WELL-MIXED
ENVIRONMENT DEVELOPING LATE MONDAY MORNING INTO THE AFTERNOON AS
LAPSE RATES APPROXIMATE TO DRY ADIABATIC UP TO 800MB. MOMENTUM LOOKS
RATHER UNIFORMLY DISTRIBUTED THROUGH THE LAYER AND WILL BE
SUPPORTIVE OF GUSTINESS TO THE TUNE OF AROUND 20 KNOTS. DEEP MIXING
WILL ALSO SUPPORT A HIGH BASED STRATOCU DECK BY AFTERNOON,
ESPECIALLY ACROSS THE NORTH AS ANOTHER QUICK-MOVING EMBEDDED WAVE
ZIPS BY DURING THE DAY. NO ARGUMENTS FROM THE CONSENSUS WHICH OFFERS
HIGHS SOLIDLY IN THE MID 40S / LOW 40S IN THE THUMB.

BUILDING HIGH PRESSURE WILL EASE THE GRADIENT BY MONDAY EVENING
ALLOWING WINDS TO SLACKEN AS THE SUN SETS. ISENTROPIC ASCENT WILL
THEN INCREASE OVERNIGHT IN ADVANCE OF A FAST-MOVING SHEAR MAX WITH
ORIGINS OVER THE NORTHEAST PACIFIC. THIS WAVE WILL BRING A BRIEF
RAIN OR RAIN/SNOW MIX LATE MONDAY NIGHT. PREDICTABILITY REMAINS LOW,
BUT A LIGHT ACCUMULATION OF AN INCH OR SO WILL BE POSSIBLE OVER A
PORTION OF THE CWA DEPENDING ON THE EXACT EVOLUTION OF THE LOW-LEVEL
THERMODYNAMIC PROFILE.

THE CLIPPER SYSTEM WILL QUICKLY BE MOVING OFF THE THE EAST DURING
THE DAY ON TUESDAY. WARMING TEMPERATURES THROUGHOUT THE DAY WILL
ALLOW ANY FROZEN AND MIXED PRECIPITATION TO CHANGE OVER ENTIRELY TO
RAIN BY MID TUESDAY MORNING. WARMER TEMPERATURES AND DRY CONDITIONS
RETURN ON WEDNESDAY AND LAST INTO THURSDAY. HIGHS ON WEDNESDAY WILL
BE IN THE LOW 50S WITH HIGHS ON THURSDAY POTENTIALLY REACHING INTO
THE LOW 60S. THE NEXT LOW PRESSURE SYSTEM WILL TRACK ACROSS THE
NORTHERN GREAT LAKES DRAGGING A COLD FRONT ACROSS LOWER MICHIGAN ON
THURSDAY EVENING. THIS SYSTEM WILL BRING THE NEXT CHANCE OF RAIN
SHOWERS TO SOUTHEAST MICHIGAN...POSSIBLY LASTING THROUGH SATURDAY AS
A SERIES OF WEAK LOW PRESSURE SYSTEMS FOLLOW IN THE WAKE OF THIS
LARGER SYSTEM.

MARINE...

LIGHT SOUTHWEST WINDS TONIGHT WILL BECOME STRONG BY MIDDAY SUNDAY
AND WILL BE SUSTAINED AT NEAR-GALES OVER CENTRAL LAKE HURON BY
SUNDAY AFTERNOON. THE PRESENCE OF A MODEST AMOUNT OF COLD AIR AND
SOME OPEN WATER...AND PERHAPS EVEN SOME FUNNELING IN SAGINAW
BAY...ARE ENOUGH TO WARRANT THE ISSUANCE OF A GALE WATCH FOR SOUTH-
SOUTHWEST GALES SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR MUCH OF
LAKE HURON. WINDS WILL THEN SUBSIDE SOMEWHAT BY MIDNIGHT SUNDAY
NIGHT AND A REPRIEVE OF ABOUT 6 HOURS IS EXPECTED BEFORE NORTHWEST
GALES DEVELOP BEHIND A PASSING COLD FRONT. THIS SECOND ROUND OF
GALES WILL BE FROM THE NORTHWEST AND WILL BEGIN DURING THE PREDAWN
HOURS MONDAY AND PERSIST THROUGH MIDDAY. TRANQUIL CONDITIONS WILL
TAKE HOLD BENEATH HIGH PRESSURE ON MONDAY NIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM THIS AFTERNOON THROUGH THIS EVENING FOR LHZ362-363-
     421-422-441-462-463.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....CB
SHORT TERM...HLO
LONG TERM....JVC/RK
MARINE.......JVC


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





000
FXUS63 KDTX 282324
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
724 PM EDT SAT MAR 28 2015


.AVIATION...

VFR CONDITIONS WILL PREVAIL TONIGHT INTO MUCH OF SUNDAY...BUT
CHANGES WILL COME BY MID/LATE AFTERNOON AS A FAST MOVING LOW
PRESSURE SYSTEM FORCES A THROUGH EASTWARD INTO THE AREA. NOT ONLY
WILL THIS BRING A CHANCE OF -SHRA...AND POSSIBLE MIX WITH -SHSN FOR
KPTK NORTH...IT WILL ALSO LEAD TO STRONG SOUTHERLY FLOW AS THE
PRESSURE GRADIENT TIGHTENS IN ADVANCE AND ALONG THIS FEATURE. EXPECT
MVFR CONDITIONS TO DEVELOP 20Z-22Z WITH S-SSW WINDS GUSTING TO NEAR
30 KNOTS BETWEEN ROUGHLY 18Z-20Z AND 00Z-02Z. CONDITIONS WILL THEN
GRADUALLY IMPROVE THEREAFTER AS THIS SYSTEM EXITS TO THE EAST.

FOR DTW...VFR UNTIL 21Z OR SO SUNDAY WHEN MVFR CIGS WITH -SHRA WILL
BE POSSIBLE. SOUTHERLY WINDS...190-200 DEGREES...WILL ALSO GUST TO
25 KNOTS OR BETTER AT TIMES AFTER 18Z SUNDAY.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN CEILINGS AOB 5000 FEET AFTER 21Z SUNDAY.

* MEDIUM IN WIND GUSTS TO 25 KNOTS FROM 190-200 DEGREES BY 18Z-20Z
  SUNDAY.

&&

.PREV DISCUSSION...ISSUED 338 PM EDT SAT MAR 28 2015

SHORT TERM...THROUGH TONIGHT

WATER VAPOR IMAGERY SHOWS UPPER RIDGING BEGINNING TO CASCADE DOWN
ACROSS MICHIGAN. THIS WILL PROVIDE DRY WEATHER...MOSTLY CLEAR
SKIES...AND FAIRLY LIGHT WINDS TONIGHT AS SURFACE HIGH PRESSURE
BECOMES CENTERED OVER THE OHIO VALLEY. GOOD RADIATIONAL COOLING
CONDITIONS WILL SET UP FOR MOST OF THE NIGHT...INHIBITED ONLY LATE
AS HIGH CLOUDS ARRIVE...AS THE UPPER WAVE NOW PASSING THROUGH THE
NORTHERN ROCKIES APPROACHES THE GREAT LAKES. WARMER AIR WILL BEGIN
TO ADVECT INTO THE AREA TONIGHT AHEAD OF THIS WAVE...HOWEVER IT WILL
BE OFFSET BY RADIATIONAL COOLING. THIS WILL KEEP MIN TEMPERATURES
TONIGHT CLOSE TO MINS EXPERIENCED THIS MORNING...WELL BELOW NORMAL
IN THE TEENS.

LONG TERM...

LEE CYCLONE IN SOUTHERN SASKATCHEWAN IS CHUGGING EAST IN RESPONSE TO
HEIGHT FALLS OWING TO THE COMPACT MID-LEVEL CIRCULATION OVER THE
NORTHERN INTERMOUNTAIN WEST. THE ASSOCIATED PV ANOMALY WILL
TRANSLATE EAST WITHIN PROGRESSIVE MEAN FLOW WHILE ADDITIONAL ENERGY
OVER CENTRAL CANADA WRAPS INTO THE AMPLIFYING TROUGH. IN SOUTHEAST
MICHIGAN, THIS WILL MANIFEST AS A QUICK 1-2 PUNCH OF UPPER FORCING
WITH THE LEAD WAVE BEING STEERED ACROSS NORTHERN LAKE HURON EARLY
SUNDAY EVENING WHILE TRAILING WAVE ACTS ON RESIDUAL LOW-LEVEL
MOISTURE WITHIN A COOLING COLUMN BEGINNING LATE SUNDAY EVENING.

A STRONG 60KT LOW-LEVEL JET IS FORECAST TO DEVELOP OVER THE NORTHERN
GREAT PLAINS TONIGHT IN ADVANCE OF THE LEAD WAVE. THE LLJ IS
EXPECTED TO MAINTAIN ITS STRENGTH, AND PERHAPS EVEN BROADEN ITS
SPATIAL FOOTPRINT, BY THE TIME IT REACHES SEMI SUNDAY AFTERNOON.
FAST SYSTEM SPEED WILL LIMIT MOISTURE TRANSPORT (PWATS AROUND 0.5"),
BUT FORCING ALONG THE LEAD EDGE AND WITHIN THE STRONG MOISTURE
TRANSPORT AXIS WILL BE SUFFICIENT TO PRODUCE A BAND OF LIGHT TO
MODERATE SHOWERS MOVING W-E ACROSS THE CWA 19 THROUGH 00Z. THE
STRENGTHENING WIND FIELD WILL SUPPORT WIND GUSTS OF 25 KNOTS
AREAWIDE...POTENTIALLY 30 KNOTS IN THE SAGINAW VALLEY. THIS WILL
EASILY DRIVE TEMPERATURES INTO THE 40S PRIOR TO THE ARRIVAL OF
PRECIPITATION. MODELS CONTINUE TO WET-BULB THE COLUMN TO FREEZING AS
SHOWERS ASSOCIATED WITH THE RESIDENT LLJ TRACK INTO THE AREA,
SUPPORTING A CHANGEOVER TO ALL SNOW. HOWEVER, SUSPECT THAT THE
RELATIVELY LIGHT QPF/STRONG WAA SCENARIO MAY NOT BE IDEALLY HANDLED
AT THE GRID SCALE STILL PREFER TO LEAN TOWARD RAIN.

FORCING ASSOCIATED WITH THE TRAILING WAVE WILL BEGIN SPREADING
ACROSS LOWER MI BY 00Z. DESPITE DRY AIR WRAPPING INTO THE COLUMN
ABOVE 700MB, SUFFICIENT LOW-LEVEL MOISTURE WILL BE IN PLACE IN
ADVANCE OF THE COLD FRONT TO SUPPORT SCATTERED RAIN/SNOW SHOWERS
DURING THE EVENING. LIGHT RATES AND A WARM/WET GROUND SHOULD PREVENT
ANY ACCUMULATION.

BREEZY CONDITIONS WILL PERSIST SUNDAY NIGHT THROUGH MONDAY AFTERNOON
AS COLD ADVECTION INCREASES OVERNIGHT. GUSTS OF 15 TO 20 KNOTS WILL
PERSIST IN SPITE OF NOCTURNAL STABILIZATION COURTESY OF ONGOING
ISENTROPIC DESCENT. 850MB TEMPERATURES ARE FORECAST TO FALL TO -4 TO
-7C BY MONDAY MORNING. 12Z NAM INDICATES A VERY WELL-MIXED
ENVIRONMENT DEVELOPING LATE MONDAY MORNING INTO THE AFTERNOON AS
LAPSE RATES APPROXIMATE TO DRY ADIABATIC UP TO 800MB. MOMENTUM LOOKS
RATHER UNIFORMLY DISTRIBUTED THROUGH THE LAYER AND WILL BE
SUPPORTIVE OF GUSTINESS TO THE TUNE OF AROUND 20 KNOTS. DEEP MIXING
WILL ALSO SUPPORT A HIGH BASED STRATOCU DECK BY AFTERNOON,
ESPECIALLY ACROSS THE NORTH AS ANOTHER QUICK-MOVING EMBEDDED WAVE
ZIPS BY DURING THE DAY. NO ARGUMENTS FROM THE CONSENSUS WHICH OFFERS
HIGHS SOLIDLY IN THE MID 40S / LOW 40S IN THE THUMB.

BUILDING HIGH PRESSURE WILL EASE THE GRADIENT BY MONDAY EVENING
ALLOWING WINDS TO SLACKEN AS THE SUN SETS. ISENTROPIC ASCENT WILL
THEN INCREASE OVERNIGHT IN ADVANCE OF A FAST-MOVING SHEAR MAX WITH
ORIGINS OVER THE NORTHEAST PACIFIC. THIS WAVE WILL BRING A BRIEF
RAIN OR RAIN/SNOW MIX LATE MONDAY NIGHT. PREDICTABILITY REMAINS LOW,
BUT A LIGHT ACCUMULATION OF AN INCH OR SO WILL BE POSSIBLE OVER A
PORTION OF THE CWA DEPENDING ON THE EXACT EVOLUTION OF THE LOW-LEVEL
THERMODYNAMIC PROFILE.

THE CLIPPER SYSTEM WILL QUICKLY BE MOVING OFF THE THE EAST DURING
THE DAY ON TUESDAY. WARMING TEMPERATURES THROUGHOUT THE DAY WILL
ALLOW ANY FROZEN AND MIXED PRECIPITATION TO CHANGE OVER ENTIRELY TO
RAIN BY MID TUESDAY MORNING. WARMER TEMPERATURES AND DRY CONDITIONS
RETURN ON WEDNESDAY AND LAST INTO THURSDAY. HIGHS ON WEDNESDAY WILL
BE IN THE LOW 50S WITH HIGHS ON THURSDAY POTENTIALLY REACHING INTO
THE LOW 60S. THE NEXT LOW PRESSURE SYSTEM WILL TRACK ACROSS THE
NORTHERN GREAT LAKES DRAGGING A COLD FRONT ACROSS LOWER MICHIGAN ON
THURSDAY EVENING. THIS SYSTEM WILL BRING THE NEXT CHANCE OF RAIN
SHOWERS TO SOUTHEAST MICHIGAN...POSSIBLY LASTING THROUGH SATURDAY AS
A SERIES OF WEAK LOW PRESSURE SYSTEMS FOLLOW IN THE WAKE OF THIS
LARGER SYSTEM.

MARINE...

LIGHT SOUTHWEST WINDS TONIGHT WILL BECOME STRONG BY MIDDAY SUNDAY
AND WILL BE SUSTAINED AT NEAR-GALES OVER CENTRAL LAKE HURON BY
SUNDAY AFTERNOON. THE PRESENCE OF A MODEST AMOUNT OF COLD AIR AND
SOME OPEN WATER...AND PERHAPS EVEN SOME FUNNELING IN SAGINAW
BAY...ARE ENOUGH TO WARRANT THE ISSUANCE OF A GALE WATCH FOR SOUTH-
SOUTHWEST GALES SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR MUCH OF
LAKE HURON. WINDS WILL THEN SUBSIDE SOMEWHAT BY MIDNIGHT SUNDAY
NIGHT AND A REPRIEVE OF ABOUT 6 HOURS IS EXPECTED BEFORE NORTHWEST
GALES DEVELOP BEHIND A PASSING COLD FRONT. THIS SECOND ROUND OF
GALES WILL BE FROM THE NORTHWEST AND WILL BEGIN DURING THE PREDAWN
HOURS MONDAY AND PERSIST THROUGH MIDDAY. TRANQUIL CONDITIONS WILL
TAKE HOLD BENEATH HIGH PRESSURE ON MONDAY NIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR LHZ362-
     363-421-422-441-462-463.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....DG
SHORT TERM...HLO
LONG TERM....JVC/RK
MARINE.......JVC


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




000
FXUS63 KDTX 282324
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
724 PM EDT SAT MAR 28 2015


.AVIATION...

VFR CONDITIONS WILL PREVAIL TONIGHT INTO MUCH OF SUNDAY...BUT
CHANGES WILL COME BY MID/LATE AFTERNOON AS A FAST MOVING LOW
PRESSURE SYSTEM FORCES A THROUGH EASTWARD INTO THE AREA. NOT ONLY
WILL THIS BRING A CHANCE OF -SHRA...AND POSSIBLE MIX WITH -SHSN FOR
KPTK NORTH...IT WILL ALSO LEAD TO STRONG SOUTHERLY FLOW AS THE
PRESSURE GRADIENT TIGHTENS IN ADVANCE AND ALONG THIS FEATURE. EXPECT
MVFR CONDITIONS TO DEVELOP 20Z-22Z WITH S-SSW WINDS GUSTING TO NEAR
30 KNOTS BETWEEN ROUGHLY 18Z-20Z AND 00Z-02Z. CONDITIONS WILL THEN
GRADUALLY IMPROVE THEREAFTER AS THIS SYSTEM EXITS TO THE EAST.

FOR DTW...VFR UNTIL 21Z OR SO SUNDAY WHEN MVFR CIGS WITH -SHRA WILL
BE POSSIBLE. SOUTHERLY WINDS...190-200 DEGREES...WILL ALSO GUST TO
25 KNOTS OR BETTER AT TIMES AFTER 18Z SUNDAY.

//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN CEILINGS AOB 5000 FEET AFTER 21Z SUNDAY.

* MEDIUM IN WIND GUSTS TO 25 KNOTS FROM 190-200 DEGREES BY 18Z-20Z
  SUNDAY.

&&

.PREV DISCUSSION...ISSUED 338 PM EDT SAT MAR 28 2015

SHORT TERM...THROUGH TONIGHT

WATER VAPOR IMAGERY SHOWS UPPER RIDGING BEGINNING TO CASCADE DOWN
ACROSS MICHIGAN. THIS WILL PROVIDE DRY WEATHER...MOSTLY CLEAR
SKIES...AND FAIRLY LIGHT WINDS TONIGHT AS SURFACE HIGH PRESSURE
BECOMES CENTERED OVER THE OHIO VALLEY. GOOD RADIATIONAL COOLING
CONDITIONS WILL SET UP FOR MOST OF THE NIGHT...INHIBITED ONLY LATE
AS HIGH CLOUDS ARRIVE...AS THE UPPER WAVE NOW PASSING THROUGH THE
NORTHERN ROCKIES APPROACHES THE GREAT LAKES. WARMER AIR WILL BEGIN
TO ADVECT INTO THE AREA TONIGHT AHEAD OF THIS WAVE...HOWEVER IT WILL
BE OFFSET BY RADIATIONAL COOLING. THIS WILL KEEP MIN TEMPERATURES
TONIGHT CLOSE TO MINS EXPERIENCED THIS MORNING...WELL BELOW NORMAL
IN THE TEENS.

LONG TERM...

LEE CYCLONE IN SOUTHERN SASKATCHEWAN IS CHUGGING EAST IN RESPONSE TO
HEIGHT FALLS OWING TO THE COMPACT MID-LEVEL CIRCULATION OVER THE
NORTHERN INTERMOUNTAIN WEST. THE ASSOCIATED PV ANOMALY WILL
TRANSLATE EAST WITHIN PROGRESSIVE MEAN FLOW WHILE ADDITIONAL ENERGY
OVER CENTRAL CANADA WRAPS INTO THE AMPLIFYING TROUGH. IN SOUTHEAST
MICHIGAN, THIS WILL MANIFEST AS A QUICK 1-2 PUNCH OF UPPER FORCING
WITH THE LEAD WAVE BEING STEERED ACROSS NORTHERN LAKE HURON EARLY
SUNDAY EVENING WHILE TRAILING WAVE ACTS ON RESIDUAL LOW-LEVEL
MOISTURE WITHIN A COOLING COLUMN BEGINNING LATE SUNDAY EVENING.

A STRONG 60KT LOW-LEVEL JET IS FORECAST TO DEVELOP OVER THE NORTHERN
GREAT PLAINS TONIGHT IN ADVANCE OF THE LEAD WAVE. THE LLJ IS
EXPECTED TO MAINTAIN ITS STRENGTH, AND PERHAPS EVEN BROADEN ITS
SPATIAL FOOTPRINT, BY THE TIME IT REACHES SEMI SUNDAY AFTERNOON.
FAST SYSTEM SPEED WILL LIMIT MOISTURE TRANSPORT (PWATS AROUND 0.5"),
BUT FORCING ALONG THE LEAD EDGE AND WITHIN THE STRONG MOISTURE
TRANSPORT AXIS WILL BE SUFFICIENT TO PRODUCE A BAND OF LIGHT TO
MODERATE SHOWERS MOVING W-E ACROSS THE CWA 19 THROUGH 00Z. THE
STRENGTHENING WIND FIELD WILL SUPPORT WIND GUSTS OF 25 KNOTS
AREAWIDE...POTENTIALLY 30 KNOTS IN THE SAGINAW VALLEY. THIS WILL
EASILY DRIVE TEMPERATURES INTO THE 40S PRIOR TO THE ARRIVAL OF
PRECIPITATION. MODELS CONTINUE TO WET-BULB THE COLUMN TO FREEZING AS
SHOWERS ASSOCIATED WITH THE RESIDENT LLJ TRACK INTO THE AREA,
SUPPORTING A CHANGEOVER TO ALL SNOW. HOWEVER, SUSPECT THAT THE
RELATIVELY LIGHT QPF/STRONG WAA SCENARIO MAY NOT BE IDEALLY HANDLED
AT THE GRID SCALE STILL PREFER TO LEAN TOWARD RAIN.

FORCING ASSOCIATED WITH THE TRAILING WAVE WILL BEGIN SPREADING
ACROSS LOWER MI BY 00Z. DESPITE DRY AIR WRAPPING INTO THE COLUMN
ABOVE 700MB, SUFFICIENT LOW-LEVEL MOISTURE WILL BE IN PLACE IN
ADVANCE OF THE COLD FRONT TO SUPPORT SCATTERED RAIN/SNOW SHOWERS
DURING THE EVENING. LIGHT RATES AND A WARM/WET GROUND SHOULD PREVENT
ANY ACCUMULATION.

BREEZY CONDITIONS WILL PERSIST SUNDAY NIGHT THROUGH MONDAY AFTERNOON
AS COLD ADVECTION INCREASES OVERNIGHT. GUSTS OF 15 TO 20 KNOTS WILL
PERSIST IN SPITE OF NOCTURNAL STABILIZATION COURTESY OF ONGOING
ISENTROPIC DESCENT. 850MB TEMPERATURES ARE FORECAST TO FALL TO -4 TO
-7C BY MONDAY MORNING. 12Z NAM INDICATES A VERY WELL-MIXED
ENVIRONMENT DEVELOPING LATE MONDAY MORNING INTO THE AFTERNOON AS
LAPSE RATES APPROXIMATE TO DRY ADIABATIC UP TO 800MB. MOMENTUM LOOKS
RATHER UNIFORMLY DISTRIBUTED THROUGH THE LAYER AND WILL BE
SUPPORTIVE OF GUSTINESS TO THE TUNE OF AROUND 20 KNOTS. DEEP MIXING
WILL ALSO SUPPORT A HIGH BASED STRATOCU DECK BY AFTERNOON,
ESPECIALLY ACROSS THE NORTH AS ANOTHER QUICK-MOVING EMBEDDED WAVE
ZIPS BY DURING THE DAY. NO ARGUMENTS FROM THE CONSENSUS WHICH OFFERS
HIGHS SOLIDLY IN THE MID 40S / LOW 40S IN THE THUMB.

BUILDING HIGH PRESSURE WILL EASE THE GRADIENT BY MONDAY EVENING
ALLOWING WINDS TO SLACKEN AS THE SUN SETS. ISENTROPIC ASCENT WILL
THEN INCREASE OVERNIGHT IN ADVANCE OF A FAST-MOVING SHEAR MAX WITH
ORIGINS OVER THE NORTHEAST PACIFIC. THIS WAVE WILL BRING A BRIEF
RAIN OR RAIN/SNOW MIX LATE MONDAY NIGHT. PREDICTABILITY REMAINS LOW,
BUT A LIGHT ACCUMULATION OF AN INCH OR SO WILL BE POSSIBLE OVER A
PORTION OF THE CWA DEPENDING ON THE EXACT EVOLUTION OF THE LOW-LEVEL
THERMODYNAMIC PROFILE.

THE CLIPPER SYSTEM WILL QUICKLY BE MOVING OFF THE THE EAST DURING
THE DAY ON TUESDAY. WARMING TEMPERATURES THROUGHOUT THE DAY WILL
ALLOW ANY FROZEN AND MIXED PRECIPITATION TO CHANGE OVER ENTIRELY TO
RAIN BY MID TUESDAY MORNING. WARMER TEMPERATURES AND DRY CONDITIONS
RETURN ON WEDNESDAY AND LAST INTO THURSDAY. HIGHS ON WEDNESDAY WILL
BE IN THE LOW 50S WITH HIGHS ON THURSDAY POTENTIALLY REACHING INTO
THE LOW 60S. THE NEXT LOW PRESSURE SYSTEM WILL TRACK ACROSS THE
NORTHERN GREAT LAKES DRAGGING A COLD FRONT ACROSS LOWER MICHIGAN ON
THURSDAY EVENING. THIS SYSTEM WILL BRING THE NEXT CHANCE OF RAIN
SHOWERS TO SOUTHEAST MICHIGAN...POSSIBLY LASTING THROUGH SATURDAY AS
A SERIES OF WEAK LOW PRESSURE SYSTEMS FOLLOW IN THE WAKE OF THIS
LARGER SYSTEM.

MARINE...

LIGHT SOUTHWEST WINDS TONIGHT WILL BECOME STRONG BY MIDDAY SUNDAY
AND WILL BE SUSTAINED AT NEAR-GALES OVER CENTRAL LAKE HURON BY
SUNDAY AFTERNOON. THE PRESENCE OF A MODEST AMOUNT OF COLD AIR AND
SOME OPEN WATER...AND PERHAPS EVEN SOME FUNNELING IN SAGINAW
BAY...ARE ENOUGH TO WARRANT THE ISSUANCE OF A GALE WATCH FOR SOUTH-
SOUTHWEST GALES SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR MUCH OF
LAKE HURON. WINDS WILL THEN SUBSIDE SOMEWHAT BY MIDNIGHT SUNDAY
NIGHT AND A REPRIEVE OF ABOUT 6 HOURS IS EXPECTED BEFORE NORTHWEST
GALES DEVELOP BEHIND A PASSING COLD FRONT. THIS SECOND ROUND OF
GALES WILL BE FROM THE NORTHWEST AND WILL BEGIN DURING THE PREDAWN
HOURS MONDAY AND PERSIST THROUGH MIDDAY. TRANQUIL CONDITIONS WILL
TAKE HOLD BENEATH HIGH PRESSURE ON MONDAY NIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR LHZ362-
     363-421-422-441-462-463.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....DG
SHORT TERM...HLO
LONG TERM....JVC/RK
MARINE.......JVC


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





000
FXUS63 KDTX 281938
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
338 PM EDT SAT MAR 28 2015

.SHORT TERM...THROUGH TONIGHT

WATER VAPOR IMAGERY SHOWS UPPER RIDGING BEGINNING TO CASCADE DOWN
ACROSS MICHIGAN. THIS WILL PROVIDE DRY WEATHER...MOSTLY CLEAR
SKIES...AND FAIRLY LIGHT WINDS TONIGHT AS SURFACE HIGH PRESSURE
BECOMES CENTERED OVER THE OHIO VALLEY. GOOD RADIATIONAL COOLING
CONDITIONS WILL SET UP FOR MOST OF THE NIGHT...INHIBITED ONLY LATE
AS HIGH CLOUDS ARRIVE...AS THE UPPER WAVE NOW PASSING THROUGH THE
NORTHERN ROCKIES APPROACHES THE GREAT LAKES. WARMER AIR WILL BEGIN
TO ADVECT INTO THE AREA TONIGHT AHEAD OF THIS WAVE...HOWEVER IT WILL
BE OFFSET BY RADIATIONAL COOLING. THIS WILL KEEP MIN TEMPERATURES
TONIGHT CLOSE TO MINS EXPERIENCED THIS MORNING...WELL BELOW NORMAL
IN THE TEENS.

&&

.LONG TERM...

LEE CYCLONE IN SOUTHERN SASKATCHEWAN IS CHUGGING EAST IN RESPONSE TO
HEIGHT FALLS OWING TO THE COMPACT MID-LEVEL CIRCULATION OVER THE
NORTHERN INTERMOUNTAIN WEST. THE ASSOCIATED PV ANOMALY WILL
TRANSLATE EAST WITHIN PROGRESSIVE MEAN FLOW WHILE ADDITIONAL ENERGY
OVER CENTRAL CANADA WRAPS INTO THE AMPLIFYING TROUGH. IN SOUTHEAST
MICHIGAN, THIS WILL MANIFEST AS A QUICK 1-2 PUNCH OF UPPER FORCING
WITH THE LEAD WAVE BEING STEERED ACROSS NORTHERN LAKE HURON EARLY
SUNDAY EVENING WHILE TRAILING WAVE ACTS ON RESIDUAL LOW-LEVEL
MOISTURE WITHIN A COOLING COLUMN BEGINNING LATE SUNDAY EVENING.

A STRONG 60KT LOW-LEVEL JET IS FORECAST TO DEVELOP OVER THE NORTHERN
GREAT PLAINS TONIGHT IN ADVANCE OF THE LEAD WAVE. THE LLJ IS
EXPECTED TO MAINTAIN ITS STRENGTH, AND PERHAPS EVEN BROADEN ITS
SPATIAL FOOTPRINT, BY THE TIME IT REACHES SEMI SUNDAY AFTERNOON.
FAST SYSTEM SPEED WILL LIMIT MOISTURE TRANSPORT (PWATS AROUND 0.5"),
BUT FORCING ALONG THE LEAD EDGE AND WITHIN THE STRONG MOISTURE
TRANSPORT AXIS WILL BE SUFFICIENT TO PRODUCE A BAND OF LIGHT TO
MODERATE SHOWERS MOVING W-E ACROSS THE CWA 19 THROUGH 00Z. THE
STRENGTHENING WIND FIELD WILL SUPPORT WIND GUSTS OF 25 KNOTS
AREAWIDE...POTENTIALLY 30 KNOTS IN THE SAGINAW VALLEY. THIS WILL
EASILY DRIVE TEMPERATURES INTO THE 40S PRIOR TO THE ARRIVAL OF
PRECIPITATION. MODELS CONTINUE TO WET-BULB THE COLUMN TO FREEZING AS
SHOWERS ASSOCIATED WITH THE RESIDENT LLJ TRACK INTO THE AREA,
SUPPORTING A CHANGEOVER TO ALL SNOW. HOWEVER, SUSPECT THAT THE
RELATIVELY LIGHT QPF/STRONG WAA SCENARIO MAY NOT BE IDEALLY HANDLED
AT THE GRID SCALE STILL PREFER TO LEAN TOWARD RAIN.

FORCING ASSOCIATED WITH THE TRAILING WAVE WILL BEGIN SPREADING
ACROSS LOWER MI BY 00Z. DESPITE DRY AIR WRAPPING INTO THE COLUMN
ABOVE 700MB, SUFFICIENT LOW-LEVEL MOISTURE WILL BE IN PLACE IN
ADVANCE OF THE COLD FRONT TO SUPPORT SCATTERED RAIN/SNOW SHOWERS
DURING THE EVENING. LIGHT RATES AND A WARM/WET GROUND SHOULD PREVENT
ANY ACCUMULATION.

BREEZY CONDITIONS WILL PERSIST SUNDAY NIGHT THROUGH MONDAY AFTERNOON
AS COLD ADVECTION INCREASES OVERNIGHT. GUSTS OF 15 TO 20 KNOTS WILL
PERSIST IN SPITE OF NOCTURNAL STABILIZATION COURTESY OF ONGOING
ISENTROPIC DESCENT. 850MB TEMPERATURES ARE FORECAST TO FALL TO -4 TO
-7C BY MONDAY MORNING. 12Z NAM INDICATES A VERY WELL-MIXED
ENVIRONMENT DEVELOPING LATE MONDAY MORNING INTO THE AFTERNOON AS
LAPSE RATES APPROXIMATE TO DRY ADIABATIC UP TO 800MB. MOMENTUM LOOKS
RATHER UNIFORMLY DISTRIBUTED THROUGH THE LAYER AND WILL BE
SUPPORTIVE OF GUSTINESS TO THE TUNE OF AROUND 20 KNOTS. DEEP MIXING
WILL ALSO SUPPORT A HIGH BASED STRATOCU DECK BY AFTERNOON,
ESPECIALLY ACROSS THE NORTH AS ANOTHER QUICK-MOVING EMBEDDED WAVE
ZIPS BY DURING THE DAY. NO ARGUMENTS FROM THE CONSENSUS WHICH OFFERS
HIGHS SOLIDLY IN THE MID 40S / LOW 40S IN THE THUMB.

BUILDING HIGH PRESSURE WILL EASE THE GRADIENT BY MONDAY EVENING
ALLOWING WINDS TO SLACKEN AS THE SUN SETS. ISENTROPIC ASCENT WILL
THEN INCREASE OVERNIGHT IN ADVANCE OF A FAST-MOVING SHEAR MAX WITH
ORIGINS OVER THE NORTHEAST PACIFIC. THIS WAVE WILL BRING A BRIEF
RAIN OR RAIN/SNOW MIX LATE MONDAY NIGHT. PREDICTABILITY REMAINS LOW,
BUT A LIGHT ACCUMULATION OF AN INCH OR SO WILL BE POSSIBLE OVER A
PORTION OF THE CWA DEPENDING ON THE EXACT EVOLUTION OF THE LOW-LEVEL
THERMODYNAMIC PROFILE.

THE CLIPPER SYSTEM WILL QUICKLY BE MOVING OFF THE THE EAST DURING
THE DAY ON TUESDAY. WARMING TEMPERATURES THROUGHOUT THE DAY WILL
ALLOW ANY FROZEN AND MIXED PRECIPITATION TO CHANGE OVER ENTIRELY TO
RAIN BY MID TUESDAY MORNING. WARMER TEMPERATURES AND DRY CONDITIONS
RETURN ON WEDNESDAY AND LAST INTO THURSDAY. HIGHS ON WEDNESDAY WILL
BE IN THE LOW 50S WITH HIGHS ON THURSDAY POTENTIALLY REACHING INTO
THE LOW 60S. THE NEXT LOW PRESSURE SYSTEM WILL TRACK ACROSS THE
NORTHERN GREAT LAKES DRAGGING A COLD FRONT ACROSS LOWER MICHIGAN ON
THURSDAY EVENING. THIS SYSTEM WILL BRING THE NEXT CHANCE OF RAIN
SHOWERS TO SOUTHEAST MICHIGAN...POSSIBLY LASTING THROUGH SATURDAY AS
A SERIES OF WEAK LOW PRESSURE SYSTEMS FOLLOW IN THE WAKE OF THIS
LARGER SYSTEM.

&&

.MARINE...

LIGHT SOUTHWEST WINDS TONIGHT WILL BECOME STRONG BY MIDDAY SUNDAY
AND WILL BE SUSTAINED AT NEAR-GALES OVER CENTRAL LAKE HURON BY
SUNDAY AFTERNOON. THE PRESENCE OF A MODEST AMOUNT OF COLD AIR AND
SOME OPEN WATER...AND PERHAPS EVEN SOME FUNNELING IN SAGINAW
BAY...ARE ENOUGH TO WARRANT THE ISSUANCE OF A GALE WATCH FOR SOUTH-
SOUTHWEST GALES SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR MUCH OF
LAKE HURON. WINDS WILL THEN SUBSIDE SOMEWHAT BY MIDNIGHT SUNDAY
NIGHT AND A REPRIEVE OF ABOUT 6 HOURS IS EXPECTED BEFORE NORTHWEST
GALES DEVELOP BEHIND A PASSING COLD FRONT. THIS SECOND ROUND OF
GALES WILL BE FROM THE NORTHWEST AND WILL BEGIN DURING THE PREDAWN
HOURS MONDAY AND PERSIST THROUGH MIDDAY. TRANQUIL CONDITIONS WILL
TAKE HOLD BENEATH HIGH PRESSURE ON MONDAY NIGHT.

&&

.AVIATION...

NORTHERLY FLOW FROM OFF LAKE HURON HAS CONTINUED TO PROVIDE SCT-BKN
CLOUDS BETWEEN 3000-4000 FEET OVER FAR EASTERN MICHIGAN SO FAR
TODAY. CLOUDS WILL CONTINUE TO THIN/DECREASE AND SHOW A GRADUAL
SHIFT TO THE EAST AS FLOW TURNS MORE WESTERLY THROUGH THE AFTERNOON.
COVERAGE AT THE TERMINALS FOR THE REMAINDER OF TODAY IS EXPECTED TO
REMAIN SCT OR LESS. VFR CONDITIONS ARE THEN EXPECTED OVERNIGHT
BEFORE AN APPROACHING LOW PRESSURE SYSTEM BRINGS A CHANCE FOR RAIN
SHOWERS AND A STOUT INCREASE IN SOUTHERLY WINDS TOMORROW.

FOR DTW...CIGS BETWEEN 3000-4000 FEET WILL CONTINUE TO SCATTER OUT
THROUGH 20Z. BEST CHANCE FOR PRECIPITATION TOMORROW WILL HOLD OFF
UNTIL 21Z.

//DTW THRESHOLD PROBABILITIES...

* NONE

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR LHZ362-
     363-421-422-441-462-463.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.

&&

$$

SHORT TERM...HLO
LONG TERM....JVC/RK
MARINE.......JVC
AVIATION.....HLO


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




000
FXUS63 KDTX 281938
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
338 PM EDT SAT MAR 28 2015

.SHORT TERM...THROUGH TONIGHT

WATER VAPOR IMAGERY SHOWS UPPER RIDGING BEGINNING TO CASCADE DOWN
ACROSS MICHIGAN. THIS WILL PROVIDE DRY WEATHER...MOSTLY CLEAR
SKIES...AND FAIRLY LIGHT WINDS TONIGHT AS SURFACE HIGH PRESSURE
BECOMES CENTERED OVER THE OHIO VALLEY. GOOD RADIATIONAL COOLING
CONDITIONS WILL SET UP FOR MOST OF THE NIGHT...INHIBITED ONLY LATE
AS HIGH CLOUDS ARRIVE...AS THE UPPER WAVE NOW PASSING THROUGH THE
NORTHERN ROCKIES APPROACHES THE GREAT LAKES. WARMER AIR WILL BEGIN
TO ADVECT INTO THE AREA TONIGHT AHEAD OF THIS WAVE...HOWEVER IT WILL
BE OFFSET BY RADIATIONAL COOLING. THIS WILL KEEP MIN TEMPERATURES
TONIGHT CLOSE TO MINS EXPERIENCED THIS MORNING...WELL BELOW NORMAL
IN THE TEENS.

&&

.LONG TERM...

LEE CYCLONE IN SOUTHERN SASKATCHEWAN IS CHUGGING EAST IN RESPONSE TO
HEIGHT FALLS OWING TO THE COMPACT MID-LEVEL CIRCULATION OVER THE
NORTHERN INTERMOUNTAIN WEST. THE ASSOCIATED PV ANOMALY WILL
TRANSLATE EAST WITHIN PROGRESSIVE MEAN FLOW WHILE ADDITIONAL ENERGY
OVER CENTRAL CANADA WRAPS INTO THE AMPLIFYING TROUGH. IN SOUTHEAST
MICHIGAN, THIS WILL MANIFEST AS A QUICK 1-2 PUNCH OF UPPER FORCING
WITH THE LEAD WAVE BEING STEERED ACROSS NORTHERN LAKE HURON EARLY
SUNDAY EVENING WHILE TRAILING WAVE ACTS ON RESIDUAL LOW-LEVEL
MOISTURE WITHIN A COOLING COLUMN BEGINNING LATE SUNDAY EVENING.

A STRONG 60KT LOW-LEVEL JET IS FORECAST TO DEVELOP OVER THE NORTHERN
GREAT PLAINS TONIGHT IN ADVANCE OF THE LEAD WAVE. THE LLJ IS
EXPECTED TO MAINTAIN ITS STRENGTH, AND PERHAPS EVEN BROADEN ITS
SPATIAL FOOTPRINT, BY THE TIME IT REACHES SEMI SUNDAY AFTERNOON.
FAST SYSTEM SPEED WILL LIMIT MOISTURE TRANSPORT (PWATS AROUND 0.5"),
BUT FORCING ALONG THE LEAD EDGE AND WITHIN THE STRONG MOISTURE
TRANSPORT AXIS WILL BE SUFFICIENT TO PRODUCE A BAND OF LIGHT TO
MODERATE SHOWERS MOVING W-E ACROSS THE CWA 19 THROUGH 00Z. THE
STRENGTHENING WIND FIELD WILL SUPPORT WIND GUSTS OF 25 KNOTS
AREAWIDE...POTENTIALLY 30 KNOTS IN THE SAGINAW VALLEY. THIS WILL
EASILY DRIVE TEMPERATURES INTO THE 40S PRIOR TO THE ARRIVAL OF
PRECIPITATION. MODELS CONTINUE TO WET-BULB THE COLUMN TO FREEZING AS
SHOWERS ASSOCIATED WITH THE RESIDENT LLJ TRACK INTO THE AREA,
SUPPORTING A CHANGEOVER TO ALL SNOW. HOWEVER, SUSPECT THAT THE
RELATIVELY LIGHT QPF/STRONG WAA SCENARIO MAY NOT BE IDEALLY HANDLED
AT THE GRID SCALE STILL PREFER TO LEAN TOWARD RAIN.

FORCING ASSOCIATED WITH THE TRAILING WAVE WILL BEGIN SPREADING
ACROSS LOWER MI BY 00Z. DESPITE DRY AIR WRAPPING INTO THE COLUMN
ABOVE 700MB, SUFFICIENT LOW-LEVEL MOISTURE WILL BE IN PLACE IN
ADVANCE OF THE COLD FRONT TO SUPPORT SCATTERED RAIN/SNOW SHOWERS
DURING THE EVENING. LIGHT RATES AND A WARM/WET GROUND SHOULD PREVENT
ANY ACCUMULATION.

BREEZY CONDITIONS WILL PERSIST SUNDAY NIGHT THROUGH MONDAY AFTERNOON
AS COLD ADVECTION INCREASES OVERNIGHT. GUSTS OF 15 TO 20 KNOTS WILL
PERSIST IN SPITE OF NOCTURNAL STABILIZATION COURTESY OF ONGOING
ISENTROPIC DESCENT. 850MB TEMPERATURES ARE FORECAST TO FALL TO -4 TO
-7C BY MONDAY MORNING. 12Z NAM INDICATES A VERY WELL-MIXED
ENVIRONMENT DEVELOPING LATE MONDAY MORNING INTO THE AFTERNOON AS
LAPSE RATES APPROXIMATE TO DRY ADIABATIC UP TO 800MB. MOMENTUM LOOKS
RATHER UNIFORMLY DISTRIBUTED THROUGH THE LAYER AND WILL BE
SUPPORTIVE OF GUSTINESS TO THE TUNE OF AROUND 20 KNOTS. DEEP MIXING
WILL ALSO SUPPORT A HIGH BASED STRATOCU DECK BY AFTERNOON,
ESPECIALLY ACROSS THE NORTH AS ANOTHER QUICK-MOVING EMBEDDED WAVE
ZIPS BY DURING THE DAY. NO ARGUMENTS FROM THE CONSENSUS WHICH OFFERS
HIGHS SOLIDLY IN THE MID 40S / LOW 40S IN THE THUMB.

BUILDING HIGH PRESSURE WILL EASE THE GRADIENT BY MONDAY EVENING
ALLOWING WINDS TO SLACKEN AS THE SUN SETS. ISENTROPIC ASCENT WILL
THEN INCREASE OVERNIGHT IN ADVANCE OF A FAST-MOVING SHEAR MAX WITH
ORIGINS OVER THE NORTHEAST PACIFIC. THIS WAVE WILL BRING A BRIEF
RAIN OR RAIN/SNOW MIX LATE MONDAY NIGHT. PREDICTABILITY REMAINS LOW,
BUT A LIGHT ACCUMULATION OF AN INCH OR SO WILL BE POSSIBLE OVER A
PORTION OF THE CWA DEPENDING ON THE EXACT EVOLUTION OF THE LOW-LEVEL
THERMODYNAMIC PROFILE.

THE CLIPPER SYSTEM WILL QUICKLY BE MOVING OFF THE THE EAST DURING
THE DAY ON TUESDAY. WARMING TEMPERATURES THROUGHOUT THE DAY WILL
ALLOW ANY FROZEN AND MIXED PRECIPITATION TO CHANGE OVER ENTIRELY TO
RAIN BY MID TUESDAY MORNING. WARMER TEMPERATURES AND DRY CONDITIONS
RETURN ON WEDNESDAY AND LAST INTO THURSDAY. HIGHS ON WEDNESDAY WILL
BE IN THE LOW 50S WITH HIGHS ON THURSDAY POTENTIALLY REACHING INTO
THE LOW 60S. THE NEXT LOW PRESSURE SYSTEM WILL TRACK ACROSS THE
NORTHERN GREAT LAKES DRAGGING A COLD FRONT ACROSS LOWER MICHIGAN ON
THURSDAY EVENING. THIS SYSTEM WILL BRING THE NEXT CHANCE OF RAIN
SHOWERS TO SOUTHEAST MICHIGAN...POSSIBLY LASTING THROUGH SATURDAY AS
A SERIES OF WEAK LOW PRESSURE SYSTEMS FOLLOW IN THE WAKE OF THIS
LARGER SYSTEM.

&&

.MARINE...

LIGHT SOUTHWEST WINDS TONIGHT WILL BECOME STRONG BY MIDDAY SUNDAY
AND WILL BE SUSTAINED AT NEAR-GALES OVER CENTRAL LAKE HURON BY
SUNDAY AFTERNOON. THE PRESENCE OF A MODEST AMOUNT OF COLD AIR AND
SOME OPEN WATER...AND PERHAPS EVEN SOME FUNNELING IN SAGINAW
BAY...ARE ENOUGH TO WARRANT THE ISSUANCE OF A GALE WATCH FOR SOUTH-
SOUTHWEST GALES SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR MUCH OF
LAKE HURON. WINDS WILL THEN SUBSIDE SOMEWHAT BY MIDNIGHT SUNDAY
NIGHT AND A REPRIEVE OF ABOUT 6 HOURS IS EXPECTED BEFORE NORTHWEST
GALES DEVELOP BEHIND A PASSING COLD FRONT. THIS SECOND ROUND OF
GALES WILL BE FROM THE NORTHWEST AND WILL BEGIN DURING THE PREDAWN
HOURS MONDAY AND PERSIST THROUGH MIDDAY. TRANQUIL CONDITIONS WILL
TAKE HOLD BENEATH HIGH PRESSURE ON MONDAY NIGHT.

&&

.AVIATION...

NORTHERLY FLOW FROM OFF LAKE HURON HAS CONTINUED TO PROVIDE SCT-BKN
CLOUDS BETWEEN 3000-4000 FEET OVER FAR EASTERN MICHIGAN SO FAR
TODAY. CLOUDS WILL CONTINUE TO THIN/DECREASE AND SHOW A GRADUAL
SHIFT TO THE EAST AS FLOW TURNS MORE WESTERLY THROUGH THE AFTERNOON.
COVERAGE AT THE TERMINALS FOR THE REMAINDER OF TODAY IS EXPECTED TO
REMAIN SCT OR LESS. VFR CONDITIONS ARE THEN EXPECTED OVERNIGHT
BEFORE AN APPROACHING LOW PRESSURE SYSTEM BRINGS A CHANCE FOR RAIN
SHOWERS AND A STOUT INCREASE IN SOUTHERLY WINDS TOMORROW.

FOR DTW...CIGS BETWEEN 3000-4000 FEET WILL CONTINUE TO SCATTER OUT
THROUGH 20Z. BEST CHANCE FOR PRECIPITATION TOMORROW WILL HOLD OFF
UNTIL 21Z.

//DTW THRESHOLD PROBABILITIES...

* NONE

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR LHZ362-
     363-421-422-441-462-463.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.

&&

$$

SHORT TERM...HLO
LONG TERM....JVC/RK
MARINE.......JVC
AVIATION.....HLO


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




000
FXUS63 KDTX 281938
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
338 PM EDT SAT MAR 28 2015

.SHORT TERM...THROUGH TONIGHT

WATER VAPOR IMAGERY SHOWS UPPER RIDGING BEGINNING TO CASCADE DOWN
ACROSS MICHIGAN. THIS WILL PROVIDE DRY WEATHER...MOSTLY CLEAR
SKIES...AND FAIRLY LIGHT WINDS TONIGHT AS SURFACE HIGH PRESSURE
BECOMES CENTERED OVER THE OHIO VALLEY. GOOD RADIATIONAL COOLING
CONDITIONS WILL SET UP FOR MOST OF THE NIGHT...INHIBITED ONLY LATE
AS HIGH CLOUDS ARRIVE...AS THE UPPER WAVE NOW PASSING THROUGH THE
NORTHERN ROCKIES APPROACHES THE GREAT LAKES. WARMER AIR WILL BEGIN
TO ADVECT INTO THE AREA TONIGHT AHEAD OF THIS WAVE...HOWEVER IT WILL
BE OFFSET BY RADIATIONAL COOLING. THIS WILL KEEP MIN TEMPERATURES
TONIGHT CLOSE TO MINS EXPERIENCED THIS MORNING...WELL BELOW NORMAL
IN THE TEENS.

&&

.LONG TERM...

LEE CYCLONE IN SOUTHERN SASKATCHEWAN IS CHUGGING EAST IN RESPONSE TO
HEIGHT FALLS OWING TO THE COMPACT MID-LEVEL CIRCULATION OVER THE
NORTHERN INTERMOUNTAIN WEST. THE ASSOCIATED PV ANOMALY WILL
TRANSLATE EAST WITHIN PROGRESSIVE MEAN FLOW WHILE ADDITIONAL ENERGY
OVER CENTRAL CANADA WRAPS INTO THE AMPLIFYING TROUGH. IN SOUTHEAST
MICHIGAN, THIS WILL MANIFEST AS A QUICK 1-2 PUNCH OF UPPER FORCING
WITH THE LEAD WAVE BEING STEERED ACROSS NORTHERN LAKE HURON EARLY
SUNDAY EVENING WHILE TRAILING WAVE ACTS ON RESIDUAL LOW-LEVEL
MOISTURE WITHIN A COOLING COLUMN BEGINNING LATE SUNDAY EVENING.

A STRONG 60KT LOW-LEVEL JET IS FORECAST TO DEVELOP OVER THE NORTHERN
GREAT PLAINS TONIGHT IN ADVANCE OF THE LEAD WAVE. THE LLJ IS
EXPECTED TO MAINTAIN ITS STRENGTH, AND PERHAPS EVEN BROADEN ITS
SPATIAL FOOTPRINT, BY THE TIME IT REACHES SEMI SUNDAY AFTERNOON.
FAST SYSTEM SPEED WILL LIMIT MOISTURE TRANSPORT (PWATS AROUND 0.5"),
BUT FORCING ALONG THE LEAD EDGE AND WITHIN THE STRONG MOISTURE
TRANSPORT AXIS WILL BE SUFFICIENT TO PRODUCE A BAND OF LIGHT TO
MODERATE SHOWERS MOVING W-E ACROSS THE CWA 19 THROUGH 00Z. THE
STRENGTHENING WIND FIELD WILL SUPPORT WIND GUSTS OF 25 KNOTS
AREAWIDE...POTENTIALLY 30 KNOTS IN THE SAGINAW VALLEY. THIS WILL
EASILY DRIVE TEMPERATURES INTO THE 40S PRIOR TO THE ARRIVAL OF
PRECIPITATION. MODELS CONTINUE TO WET-BULB THE COLUMN TO FREEZING AS
SHOWERS ASSOCIATED WITH THE RESIDENT LLJ TRACK INTO THE AREA,
SUPPORTING A CHANGEOVER TO ALL SNOW. HOWEVER, SUSPECT THAT THE
RELATIVELY LIGHT QPF/STRONG WAA SCENARIO MAY NOT BE IDEALLY HANDLED
AT THE GRID SCALE STILL PREFER TO LEAN TOWARD RAIN.

FORCING ASSOCIATED WITH THE TRAILING WAVE WILL BEGIN SPREADING
ACROSS LOWER MI BY 00Z. DESPITE DRY AIR WRAPPING INTO THE COLUMN
ABOVE 700MB, SUFFICIENT LOW-LEVEL MOISTURE WILL BE IN PLACE IN
ADVANCE OF THE COLD FRONT TO SUPPORT SCATTERED RAIN/SNOW SHOWERS
DURING THE EVENING. LIGHT RATES AND A WARM/WET GROUND SHOULD PREVENT
ANY ACCUMULATION.

BREEZY CONDITIONS WILL PERSIST SUNDAY NIGHT THROUGH MONDAY AFTERNOON
AS COLD ADVECTION INCREASES OVERNIGHT. GUSTS OF 15 TO 20 KNOTS WILL
PERSIST IN SPITE OF NOCTURNAL STABILIZATION COURTESY OF ONGOING
ISENTROPIC DESCENT. 850MB TEMPERATURES ARE FORECAST TO FALL TO -4 TO
-7C BY MONDAY MORNING. 12Z NAM INDICATES A VERY WELL-MIXED
ENVIRONMENT DEVELOPING LATE MONDAY MORNING INTO THE AFTERNOON AS
LAPSE RATES APPROXIMATE TO DRY ADIABATIC UP TO 800MB. MOMENTUM LOOKS
RATHER UNIFORMLY DISTRIBUTED THROUGH THE LAYER AND WILL BE
SUPPORTIVE OF GUSTINESS TO THE TUNE OF AROUND 20 KNOTS. DEEP MIXING
WILL ALSO SUPPORT A HIGH BASED STRATOCU DECK BY AFTERNOON,
ESPECIALLY ACROSS THE NORTH AS ANOTHER QUICK-MOVING EMBEDDED WAVE
ZIPS BY DURING THE DAY. NO ARGUMENTS FROM THE CONSENSUS WHICH OFFERS
HIGHS SOLIDLY IN THE MID 40S / LOW 40S IN THE THUMB.

BUILDING HIGH PRESSURE WILL EASE THE GRADIENT BY MONDAY EVENING
ALLOWING WINDS TO SLACKEN AS THE SUN SETS. ISENTROPIC ASCENT WILL
THEN INCREASE OVERNIGHT IN ADVANCE OF A FAST-MOVING SHEAR MAX WITH
ORIGINS OVER THE NORTHEAST PACIFIC. THIS WAVE WILL BRING A BRIEF
RAIN OR RAIN/SNOW MIX LATE MONDAY NIGHT. PREDICTABILITY REMAINS LOW,
BUT A LIGHT ACCUMULATION OF AN INCH OR SO WILL BE POSSIBLE OVER A
PORTION OF THE CWA DEPENDING ON THE EXACT EVOLUTION OF THE LOW-LEVEL
THERMODYNAMIC PROFILE.

THE CLIPPER SYSTEM WILL QUICKLY BE MOVING OFF THE THE EAST DURING
THE DAY ON TUESDAY. WARMING TEMPERATURES THROUGHOUT THE DAY WILL
ALLOW ANY FROZEN AND MIXED PRECIPITATION TO CHANGE OVER ENTIRELY TO
RAIN BY MID TUESDAY MORNING. WARMER TEMPERATURES AND DRY CONDITIONS
RETURN ON WEDNESDAY AND LAST INTO THURSDAY. HIGHS ON WEDNESDAY WILL
BE IN THE LOW 50S WITH HIGHS ON THURSDAY POTENTIALLY REACHING INTO
THE LOW 60S. THE NEXT LOW PRESSURE SYSTEM WILL TRACK ACROSS THE
NORTHERN GREAT LAKES DRAGGING A COLD FRONT ACROSS LOWER MICHIGAN ON
THURSDAY EVENING. THIS SYSTEM WILL BRING THE NEXT CHANCE OF RAIN
SHOWERS TO SOUTHEAST MICHIGAN...POSSIBLY LASTING THROUGH SATURDAY AS
A SERIES OF WEAK LOW PRESSURE SYSTEMS FOLLOW IN THE WAKE OF THIS
LARGER SYSTEM.

&&

.MARINE...

LIGHT SOUTHWEST WINDS TONIGHT WILL BECOME STRONG BY MIDDAY SUNDAY
AND WILL BE SUSTAINED AT NEAR-GALES OVER CENTRAL LAKE HURON BY
SUNDAY AFTERNOON. THE PRESENCE OF A MODEST AMOUNT OF COLD AIR AND
SOME OPEN WATER...AND PERHAPS EVEN SOME FUNNELING IN SAGINAW
BAY...ARE ENOUGH TO WARRANT THE ISSUANCE OF A GALE WATCH FOR SOUTH-
SOUTHWEST GALES SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR MUCH OF
LAKE HURON. WINDS WILL THEN SUBSIDE SOMEWHAT BY MIDNIGHT SUNDAY
NIGHT AND A REPRIEVE OF ABOUT 6 HOURS IS EXPECTED BEFORE NORTHWEST
GALES DEVELOP BEHIND A PASSING COLD FRONT. THIS SECOND ROUND OF
GALES WILL BE FROM THE NORTHWEST AND WILL BEGIN DURING THE PREDAWN
HOURS MONDAY AND PERSIST THROUGH MIDDAY. TRANQUIL CONDITIONS WILL
TAKE HOLD BENEATH HIGH PRESSURE ON MONDAY NIGHT.

&&

.AVIATION...

NORTHERLY FLOW FROM OFF LAKE HURON HAS CONTINUED TO PROVIDE SCT-BKN
CLOUDS BETWEEN 3000-4000 FEET OVER FAR EASTERN MICHIGAN SO FAR
TODAY. CLOUDS WILL CONTINUE TO THIN/DECREASE AND SHOW A GRADUAL
SHIFT TO THE EAST AS FLOW TURNS MORE WESTERLY THROUGH THE AFTERNOON.
COVERAGE AT THE TERMINALS FOR THE REMAINDER OF TODAY IS EXPECTED TO
REMAIN SCT OR LESS. VFR CONDITIONS ARE THEN EXPECTED OVERNIGHT
BEFORE AN APPROACHING LOW PRESSURE SYSTEM BRINGS A CHANCE FOR RAIN
SHOWERS AND A STOUT INCREASE IN SOUTHERLY WINDS TOMORROW.

FOR DTW...CIGS BETWEEN 3000-4000 FEET WILL CONTINUE TO SCATTER OUT
THROUGH 20Z. BEST CHANCE FOR PRECIPITATION TOMORROW WILL HOLD OFF
UNTIL 21Z.

//DTW THRESHOLD PROBABILITIES...

* NONE

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR LHZ362-
     363-421-422-441-462-463.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.

&&

$$

SHORT TERM...HLO
LONG TERM....JVC/RK
MARINE.......JVC
AVIATION.....HLO


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





000
FXUS63 KDTX 281736
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
136 PM EDT SAT MAR 28 2015


.AVIATION...

NORTHERLY FLOW FROM OFF LAKE HURON HAS CONTINUED TO PROVIDE SCT-BKN
CLOUDS BETWEEN 3000-4000 FEET OVER FAR EASTERN MICHIGAN SO FAR
TODAY. CLOUDS WILL CONTINUE TO THIN/DECREASE AND SHOW A GRADUAL
SHIFT TO THE EAST AS FLOW TURNS MORE WESTERLY THROUGH THE AFTERNOON.
COVERAGE AT THE TERMINALS FOR THE REMAINDER OF TODAY IS EXPECTED TO
REMAIN SCT OR LESS. VFR CONDITIONS ARE THEN EXPECTED OVERNIGHT
BEFORE AN APPROACHING LOW PRESSURE SYSTEM BRINGS A CHANCE FOR RAIN
SHOWERS AND A STOUT INCREASE IN SOUTHERLY WINDS TOMORROW.

FOR DTW...CIGS BETWEEN 3000-4000 FEET WILL CONTINUE TO SCATTER OUT
THROUGH 20Z. BEST CHANCE FOR PRECIPITATION TOMORROW WILL HOLD OFF
UNTIL 21Z.

//DTW THRESHOLD PROBABILITIES...

* NONE

&&

.PREV DISCUSSION...ISSUED 357 AM EDT SAT MAR 28 2015

SHORT TERM...TODAY AND TONIGHT

A COUPLE OF FACTORS HAVE COMBINED TO HELP THE SHORE PARALLEL BAND OF
LIGHT LAKE EFFECT SNOW TO PERSIST ALONG THE SHORELINE OF LAKE HURON
OVERNIGHT. THE FIRST HAS BEEN THE STREAMLINING OF NORTHERLY SURFACE
WIND TRAJECTORIES TO PRODUCE AN AREA OF LOCALIZED CONVERGENCE.
SURFACE OBSERVATIONS HAVE BEEN REPORTING A WESTERLY TRAJECTORY OVER
THE EASTERN HALF OF THE LOWER PENINSULA AND EASTERLY TRAJECTORIES AT
THE SHORELINE...PORT HOPE/SARNIA. STATIC NATURE OF THE BANDING
ON RADAR IN ADDITION TO NEGATIVE LOW LEVEL THETA E LAPSE RATES
AND NEAR SURFACE CONVERGENCE CONTINUING IN MODEL DATA THROUGH 9Z
SUGGESTS THE SNOW SHOWER POTENTIAL HAS ANOTHER 2 TO 4 HOURS. RAP
OUTPUT SUGGESTS THERE IS SOME ORGANIZED SIGNAL TO DEEPER MIDLEVEL
MOISTURE ROTATING CYCLONICALLY AROUND A CENTER POINT OVER THE
EASTERN END OF LAKE ERIE. THIS SUGGESTS THE DEEPER MOISTURE WILL
PIVOT AWAY FROM THE LOW LEVEL INSTABILITY SOURCE IN THE NEXT FEW
HOURS. THOUGHT IS AS THIS MOISTURE PUSHES SOUTHWARD AWAY FROM
SOUTHERN LAKE HURON WILL SEE LAKE EFFECT ACTIVITY WANE AFTER 9Z.
REGARDLESS...SNOW SHOWERS REMAIN LIKELY IN THE NEAR TERM WITH
MINOR ACCUMULATIONS POSSIBLE ALONG THE SHORELINE.

DIFFERENTIAL GEOPOTENTIAL HEIGHT REBOUND WILL CAUSE SURFACE HIGH
PRESSURE TO EXPAND AGGRESSIVELY EASTWARD THROUGH THE CWA BY
MIDDAY. LOW TO MIDLEVEL FLOW TRAJECTORIES DEPICT STUBBORN CYCLONIC
FLOW INTO THE LATE AFTERNOON BEFORE EVENTUALLY RELINQUISHING BY
LATE AFTERNOON. THE ARRIVAL OF THE ANTICYCLONIC FLOW WILL PROBABLY
END ANY POTENTIAL FOR CONTINUED LAKE EFFECT CLOUD THAT MAY HANG ON
ACROSS THE EASTERN CWA TODAY. WITH NORTHERLY FLOW FIRMLY IN
CONTROL...WANTED TO HANG CLOSE TO GUIDANCE WITH TEMPERATURES
AROUND 30 TO THE LOW 30S POSSIBLE.

QUIET WEATHER IS FORECASTED TONIGHT WITH HIGH PRESSURE AT THE
SURFACE AND SHORTWAVE RIDGING ALOFT. TEMPERATURES WILL AGAIN BE
COLD WITH READINGS FALLING INTO THE TEENS ACROSS ALL OF THE AREA
(10 TO 15 DEGREES BELOW AVERAGES).

LONG TERM...

SUNDAY WILL START AN ACTIVE PERIOD OF WEATHER CONSISTING OF A SERIES
OF SHORT WAVES MOVING THROUGH THE NORTHERN TIER OF STATES THROUGH
NEXT WEEK. WHILE IT WILL BE ACTIVE IN TERMS OF PRECIPITATION...THERE
WILL BE AN UNDERLYING WARMING TREND THROUGH THE PERIOD. THIS WILL BE
DRIVEN BY AN ENERGETIC PACIFIC UPPER LEVEL JET THAT WILL FORCE A
TRANSITION OUT OF THE LONG WAVE RIDGE OVER THE WEST/TROUGH OVER THE
EAST THAT HAS BEEN SO PERSISTENT AND RESISTANT TO THE ONSET OF
SPRING. THIS LARGE SCALE TRANSITION SUPPORTS GUIDANCE TEMPS OFFERING
HIGHS PUSHING 60 BY THURSDAY.

FIRST THING FIRST IS THE NEXT LOW PRESSURE SYSTEM MOVING THROUGH THE
CENTRAL ROCKIES TODAY ON SCHEDULE TO ARRIVE IN THE GREAT LAKES
SUNDAY. MODEL AGREEMENT REMAINS SOLID IN THE LATEST CYCLE WITH THE
DEPICTION OF MODEST SURFACE LEE CYCLOGENESIS OVER THE NORTHERN
PLAINS AND CANADIAN PRAIRIE...ENOUGH TO DRAW SOME GULF MODIFIED AIR
NORTHWARD TO AUGMENT MID LEVEL PACIFIC MOISTURE AND BRING
PRECIPITATION INTO SE MICHIGAN FROM MID SUNDAY AFTERNOON THROUGH
SUNDAY EVENING. THE DETERMINATION OF PRECIPITATION TYPE REMAINS
COMPLICATED BY STRONG WET BULB COOLING SHOWN IN MODEL SOUNDINGS
OPPOSED BY STRONG LOW LEVEL WARM ADVECTION. THE SAME MODEL SOUNDINGS
INDICATE THE BOUNDARY LAYER GROWING TO ABOUT 900 MB...GOOD ENOUGH
FOR SURFACE WIND GUSTS PUSHING 30 KNOTS...WHICH WILL EASILY CARRY
TEMPERATURES INTO THE LOWER 40S BEFORE THE MOISTURE ARRIVES. THE LOW
LEVEL JET CENTERED AROUND 850 MB WILL ALSO BE PUSHING 60 KNOTS WHICH
WILL BE CAPABLE OF DRIVING THE LOW LEVEL THERMAL RIDGE WELL INTO THE
SAGINAW VALLEY WITH THE ONSET OF PRECIPITATION. THE OVERALL STRENGTH
OF THE SOUTHWEST FLOW IS THEN EXPECTED TO SUPPORT AN ABOVE FREEZING
BOUNDARY LAYER TEMPERATURE PROFILE CLOSE TO 1500 FT DEEP INTO
SURFACE TEMPERATURES IN THE LOWER 40S...SUFFICIENT FOR MELTING TO
RAIN AS LONG AS PRECIPITATION RATE REMAINS AS LOW AS THAT IMPLIED BY
3 HR MODEL QPF AROUND 0.1 INCH.

A QUICK PASSAGE OF THE COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL
OCCUR SUNDAY NIGHT AND BRING A TRANSITION BACK TO SNOW SHOWERS
DURING THE EVENING. SOME LINGERING WRAP-AROUND MOISTURE WITH THE
UPPER WAVE WILL COMBINE WITH THE FRONTAL FORCING TO SUPPORT THE BEST
COVERAGE IN THE SAGINAW VALLEY AND THUMB RESULTING IN A SLUSHY
COATING BEFORE ENDING. COLD ADVECTION TRAILING THE FRONT DURING
MONDAY WILL NOT RESULT IN AS COLD AN AIR MASS AS WE ARE EXPERIENCING
THIS WEEKEND...BUT IT WILL BE ADEQUATE ENOUGH TO SET THE STAGE FOR
PRECIPITATION TYPE QUESTIONS AS THE NEXT SYSTEM ARRIVES MONDAY NIGHT
INTO TUESDAY. THIS ONE WILL BE MERELY A RIPPLE WITHIN THE BAROCLINIC
ZONE LEFT NEARBY TO THE SOUTH AND WEST AND APPEARS FRAUGHT WITH LOW
PREDICTABILITY. THE WAVE WILL BE OPEN ALOFT BUT THE MODELS OFFER A
BROAD RANGE OF SOLUTIONS ON THE DEPTH...TRACK...AND TIMING OF THE
SURFACE LOW/TROUGH. THE 00Z RUNS ARE TRENDING TOWARD A DEEPER
SURFACE WAVE MOVING THROUGH THE SOUTH HALF OF LOWER MICHIGAN LATE
MONDAY NIGHT THROUGH TUESDAY MORNING.

THE TUESDAY WAVE WILL BE THE LAST ONE BEFORE THE NORTHERN STREAM
BEGINS TO LIFT NORTHWARD WEDNESDAY INTO THURSDAY. THIS WILL BE DUE
TO THE LONG WAVE PATTERN SHIFT BEING DRIVEN BY A LARGER PACIFIC LOW
PRESSURE SYSTEM EXPECTED TO MOVE THROUGH CENTRAL CANADA THURSDAY.
GLOBAL MODEL SOLUTIONS INDICATE QUITE A BIT OF SPREAD IN THE UPPER
AIR PATTERN TOWARD THE END OF THE WEEK BUT THE DECREASED LONG WAVE
AMPLIFICATION WILL RESULT IN A MODERATING TEMPERATURE TREND IN
BETWEEN POTENTIAL ROUNDS OF SHOWERS INTO NEXT WEEKEND.

MARINE...

A BROAD AREA OF HIGH PRESSURE WILL SLIDE ACROSS THE GREAT LAKES
TODAY AND BRING FAVORABLE MARINE CONDITIONS THROUGH TONIGHT.
SOUTHWEST WIND WILL THEN INCREASE CONSIDERABLY DURING SUNDAY AS THE
NEXT LOW PRESSURE SYSTEM APPROACHES. GUSTS THROUGH SAGINAW BAY AND
OVER THE OPEN WATERS OF LAKE HURON WILL REACH 30 KNOTS BUT LIKELY
STAY BELOW GALES BEFORE MID LAKE. WARMER AIR MOVING OVER THE COLD
WATER AND REMAINING ICE WILL BE A LIMITING FACTOR DUE TO INCREASED
STABILITY. THE ASSOCIATED COLD FRONT WILL THEN SWEEP THROUGH SUNDAY
NIGHT BUT WILL NOT BRING AS MUCH COLD AIR AS WE HAVE SEEN RECENTLY.
NORTHWEST GUSTS NEAR 30 KNOTS WILL BE CONFINED TO THE NORTH HALF OF
LAKE HURON BEFORE HIGH PRESSURE BUILDS OVER THE REGION MONDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....HLO
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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





000
FXUS63 KDTX 281736
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
136 PM EDT SAT MAR 28 2015


.AVIATION...

NORTHERLY FLOW FROM OFF LAKE HURON HAS CONTINUED TO PROVIDE SCT-BKN
CLOUDS BETWEEN 3000-4000 FEET OVER FAR EASTERN MICHIGAN SO FAR
TODAY. CLOUDS WILL CONTINUE TO THIN/DECREASE AND SHOW A GRADUAL
SHIFT TO THE EAST AS FLOW TURNS MORE WESTERLY THROUGH THE AFTERNOON.
COVERAGE AT THE TERMINALS FOR THE REMAINDER OF TODAY IS EXPECTED TO
REMAIN SCT OR LESS. VFR CONDITIONS ARE THEN EXPECTED OVERNIGHT
BEFORE AN APPROACHING LOW PRESSURE SYSTEM BRINGS A CHANCE FOR RAIN
SHOWERS AND A STOUT INCREASE IN SOUTHERLY WINDS TOMORROW.

FOR DTW...CIGS BETWEEN 3000-4000 FEET WILL CONTINUE TO SCATTER OUT
THROUGH 20Z. BEST CHANCE FOR PRECIPITATION TOMORROW WILL HOLD OFF
UNTIL 21Z.

//DTW THRESHOLD PROBABILITIES...

* NONE

&&

.PREV DISCUSSION...ISSUED 357 AM EDT SAT MAR 28 2015

SHORT TERM...TODAY AND TONIGHT

A COUPLE OF FACTORS HAVE COMBINED TO HELP THE SHORE PARALLEL BAND OF
LIGHT LAKE EFFECT SNOW TO PERSIST ALONG THE SHORELINE OF LAKE HURON
OVERNIGHT. THE FIRST HAS BEEN THE STREAMLINING OF NORTHERLY SURFACE
WIND TRAJECTORIES TO PRODUCE AN AREA OF LOCALIZED CONVERGENCE.
SURFACE OBSERVATIONS HAVE BEEN REPORTING A WESTERLY TRAJECTORY OVER
THE EASTERN HALF OF THE LOWER PENINSULA AND EASTERLY TRAJECTORIES AT
THE SHORELINE...PORT HOPE/SARNIA. STATIC NATURE OF THE BANDING
ON RADAR IN ADDITION TO NEGATIVE LOW LEVEL THETA E LAPSE RATES
AND NEAR SURFACE CONVERGENCE CONTINUING IN MODEL DATA THROUGH 9Z
SUGGESTS THE SNOW SHOWER POTENTIAL HAS ANOTHER 2 TO 4 HOURS. RAP
OUTPUT SUGGESTS THERE IS SOME ORGANIZED SIGNAL TO DEEPER MIDLEVEL
MOISTURE ROTATING CYCLONICALLY AROUND A CENTER POINT OVER THE
EASTERN END OF LAKE ERIE. THIS SUGGESTS THE DEEPER MOISTURE WILL
PIVOT AWAY FROM THE LOW LEVEL INSTABILITY SOURCE IN THE NEXT FEW
HOURS. THOUGHT IS AS THIS MOISTURE PUSHES SOUTHWARD AWAY FROM
SOUTHERN LAKE HURON WILL SEE LAKE EFFECT ACTIVITY WANE AFTER 9Z.
REGARDLESS...SNOW SHOWERS REMAIN LIKELY IN THE NEAR TERM WITH
MINOR ACCUMULATIONS POSSIBLE ALONG THE SHORELINE.

DIFFERENTIAL GEOPOTENTIAL HEIGHT REBOUND WILL CAUSE SURFACE HIGH
PRESSURE TO EXPAND AGGRESSIVELY EASTWARD THROUGH THE CWA BY
MIDDAY. LOW TO MIDLEVEL FLOW TRAJECTORIES DEPICT STUBBORN CYCLONIC
FLOW INTO THE LATE AFTERNOON BEFORE EVENTUALLY RELINQUISHING BY
LATE AFTERNOON. THE ARRIVAL OF THE ANTICYCLONIC FLOW WILL PROBABLY
END ANY POTENTIAL FOR CONTINUED LAKE EFFECT CLOUD THAT MAY HANG ON
ACROSS THE EASTERN CWA TODAY. WITH NORTHERLY FLOW FIRMLY IN
CONTROL...WANTED TO HANG CLOSE TO GUIDANCE WITH TEMPERATURES
AROUND 30 TO THE LOW 30S POSSIBLE.

QUIET WEATHER IS FORECASTED TONIGHT WITH HIGH PRESSURE AT THE
SURFACE AND SHORTWAVE RIDGING ALOFT. TEMPERATURES WILL AGAIN BE
COLD WITH READINGS FALLING INTO THE TEENS ACROSS ALL OF THE AREA
(10 TO 15 DEGREES BELOW AVERAGES).

LONG TERM...

SUNDAY WILL START AN ACTIVE PERIOD OF WEATHER CONSISTING OF A SERIES
OF SHORT WAVES MOVING THROUGH THE NORTHERN TIER OF STATES THROUGH
NEXT WEEK. WHILE IT WILL BE ACTIVE IN TERMS OF PRECIPITATION...THERE
WILL BE AN UNDERLYING WARMING TREND THROUGH THE PERIOD. THIS WILL BE
DRIVEN BY AN ENERGETIC PACIFIC UPPER LEVEL JET THAT WILL FORCE A
TRANSITION OUT OF THE LONG WAVE RIDGE OVER THE WEST/TROUGH OVER THE
EAST THAT HAS BEEN SO PERSISTENT AND RESISTANT TO THE ONSET OF
SPRING. THIS LARGE SCALE TRANSITION SUPPORTS GUIDANCE TEMPS OFFERING
HIGHS PUSHING 60 BY THURSDAY.

FIRST THING FIRST IS THE NEXT LOW PRESSURE SYSTEM MOVING THROUGH THE
CENTRAL ROCKIES TODAY ON SCHEDULE TO ARRIVE IN THE GREAT LAKES
SUNDAY. MODEL AGREEMENT REMAINS SOLID IN THE LATEST CYCLE WITH THE
DEPICTION OF MODEST SURFACE LEE CYCLOGENESIS OVER THE NORTHERN
PLAINS AND CANADIAN PRAIRIE...ENOUGH TO DRAW SOME GULF MODIFIED AIR
NORTHWARD TO AUGMENT MID LEVEL PACIFIC MOISTURE AND BRING
PRECIPITATION INTO SE MICHIGAN FROM MID SUNDAY AFTERNOON THROUGH
SUNDAY EVENING. THE DETERMINATION OF PRECIPITATION TYPE REMAINS
COMPLICATED BY STRONG WET BULB COOLING SHOWN IN MODEL SOUNDINGS
OPPOSED BY STRONG LOW LEVEL WARM ADVECTION. THE SAME MODEL SOUNDINGS
INDICATE THE BOUNDARY LAYER GROWING TO ABOUT 900 MB...GOOD ENOUGH
FOR SURFACE WIND GUSTS PUSHING 30 KNOTS...WHICH WILL EASILY CARRY
TEMPERATURES INTO THE LOWER 40S BEFORE THE MOISTURE ARRIVES. THE LOW
LEVEL JET CENTERED AROUND 850 MB WILL ALSO BE PUSHING 60 KNOTS WHICH
WILL BE CAPABLE OF DRIVING THE LOW LEVEL THERMAL RIDGE WELL INTO THE
SAGINAW VALLEY WITH THE ONSET OF PRECIPITATION. THE OVERALL STRENGTH
OF THE SOUTHWEST FLOW IS THEN EXPECTED TO SUPPORT AN ABOVE FREEZING
BOUNDARY LAYER TEMPERATURE PROFILE CLOSE TO 1500 FT DEEP INTO
SURFACE TEMPERATURES IN THE LOWER 40S...SUFFICIENT FOR MELTING TO
RAIN AS LONG AS PRECIPITATION RATE REMAINS AS LOW AS THAT IMPLIED BY
3 HR MODEL QPF AROUND 0.1 INCH.

A QUICK PASSAGE OF THE COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL
OCCUR SUNDAY NIGHT AND BRING A TRANSITION BACK TO SNOW SHOWERS
DURING THE EVENING. SOME LINGERING WRAP-AROUND MOISTURE WITH THE
UPPER WAVE WILL COMBINE WITH THE FRONTAL FORCING TO SUPPORT THE BEST
COVERAGE IN THE SAGINAW VALLEY AND THUMB RESULTING IN A SLUSHY
COATING BEFORE ENDING. COLD ADVECTION TRAILING THE FRONT DURING
MONDAY WILL NOT RESULT IN AS COLD AN AIR MASS AS WE ARE EXPERIENCING
THIS WEEKEND...BUT IT WILL BE ADEQUATE ENOUGH TO SET THE STAGE FOR
PRECIPITATION TYPE QUESTIONS AS THE NEXT SYSTEM ARRIVES MONDAY NIGHT
INTO TUESDAY. THIS ONE WILL BE MERELY A RIPPLE WITHIN THE BAROCLINIC
ZONE LEFT NEARBY TO THE SOUTH AND WEST AND APPEARS FRAUGHT WITH LOW
PREDICTABILITY. THE WAVE WILL BE OPEN ALOFT BUT THE MODELS OFFER A
BROAD RANGE OF SOLUTIONS ON THE DEPTH...TRACK...AND TIMING OF THE
SURFACE LOW/TROUGH. THE 00Z RUNS ARE TRENDING TOWARD A DEEPER
SURFACE WAVE MOVING THROUGH THE SOUTH HALF OF LOWER MICHIGAN LATE
MONDAY NIGHT THROUGH TUESDAY MORNING.

THE TUESDAY WAVE WILL BE THE LAST ONE BEFORE THE NORTHERN STREAM
BEGINS TO LIFT NORTHWARD WEDNESDAY INTO THURSDAY. THIS WILL BE DUE
TO THE LONG WAVE PATTERN SHIFT BEING DRIVEN BY A LARGER PACIFIC LOW
PRESSURE SYSTEM EXPECTED TO MOVE THROUGH CENTRAL CANADA THURSDAY.
GLOBAL MODEL SOLUTIONS INDICATE QUITE A BIT OF SPREAD IN THE UPPER
AIR PATTERN TOWARD THE END OF THE WEEK BUT THE DECREASED LONG WAVE
AMPLIFICATION WILL RESULT IN A MODERATING TEMPERATURE TREND IN
BETWEEN POTENTIAL ROUNDS OF SHOWERS INTO NEXT WEEKEND.

MARINE...

A BROAD AREA OF HIGH PRESSURE WILL SLIDE ACROSS THE GREAT LAKES
TODAY AND BRING FAVORABLE MARINE CONDITIONS THROUGH TONIGHT.
SOUTHWEST WIND WILL THEN INCREASE CONSIDERABLY DURING SUNDAY AS THE
NEXT LOW PRESSURE SYSTEM APPROACHES. GUSTS THROUGH SAGINAW BAY AND
OVER THE OPEN WATERS OF LAKE HURON WILL REACH 30 KNOTS BUT LIKELY
STAY BELOW GALES BEFORE MID LAKE. WARMER AIR MOVING OVER THE COLD
WATER AND REMAINING ICE WILL BE A LIMITING FACTOR DUE TO INCREASED
STABILITY. THE ASSOCIATED COLD FRONT WILL THEN SWEEP THROUGH SUNDAY
NIGHT BUT WILL NOT BRING AS MUCH COLD AIR AS WE HAVE SEEN RECENTLY.
NORTHWEST GUSTS NEAR 30 KNOTS WILL BE CONFINED TO THE NORTH HALF OF
LAKE HURON BEFORE HIGH PRESSURE BUILDS OVER THE REGION MONDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....HLO
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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




000
FXUS63 KDTX 281736
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
136 PM EDT SAT MAR 28 2015


.AVIATION...

NORTHERLY FLOW FROM OFF LAKE HURON HAS CONTINUED TO PROVIDE SCT-BKN
CLOUDS BETWEEN 3000-4000 FEET OVER FAR EASTERN MICHIGAN SO FAR
TODAY. CLOUDS WILL CONTINUE TO THIN/DECREASE AND SHOW A GRADUAL
SHIFT TO THE EAST AS FLOW TURNS MORE WESTERLY THROUGH THE AFTERNOON.
COVERAGE AT THE TERMINALS FOR THE REMAINDER OF TODAY IS EXPECTED TO
REMAIN SCT OR LESS. VFR CONDITIONS ARE THEN EXPECTED OVERNIGHT
BEFORE AN APPROACHING LOW PRESSURE SYSTEM BRINGS A CHANCE FOR RAIN
SHOWERS AND A STOUT INCREASE IN SOUTHERLY WINDS TOMORROW.

FOR DTW...CIGS BETWEEN 3000-4000 FEET WILL CONTINUE TO SCATTER OUT
THROUGH 20Z. BEST CHANCE FOR PRECIPITATION TOMORROW WILL HOLD OFF
UNTIL 21Z.

//DTW THRESHOLD PROBABILITIES...

* NONE

&&

.PREV DISCUSSION...ISSUED 357 AM EDT SAT MAR 28 2015

SHORT TERM...TODAY AND TONIGHT

A COUPLE OF FACTORS HAVE COMBINED TO HELP THE SHORE PARALLEL BAND OF
LIGHT LAKE EFFECT SNOW TO PERSIST ALONG THE SHORELINE OF LAKE HURON
OVERNIGHT. THE FIRST HAS BEEN THE STREAMLINING OF NORTHERLY SURFACE
WIND TRAJECTORIES TO PRODUCE AN AREA OF LOCALIZED CONVERGENCE.
SURFACE OBSERVATIONS HAVE BEEN REPORTING A WESTERLY TRAJECTORY OVER
THE EASTERN HALF OF THE LOWER PENINSULA AND EASTERLY TRAJECTORIES AT
THE SHORELINE...PORT HOPE/SARNIA. STATIC NATURE OF THE BANDING
ON RADAR IN ADDITION TO NEGATIVE LOW LEVEL THETA E LAPSE RATES
AND NEAR SURFACE CONVERGENCE CONTINUING IN MODEL DATA THROUGH 9Z
SUGGESTS THE SNOW SHOWER POTENTIAL HAS ANOTHER 2 TO 4 HOURS. RAP
OUTPUT SUGGESTS THERE IS SOME ORGANIZED SIGNAL TO DEEPER MIDLEVEL
MOISTURE ROTATING CYCLONICALLY AROUND A CENTER POINT OVER THE
EASTERN END OF LAKE ERIE. THIS SUGGESTS THE DEEPER MOISTURE WILL
PIVOT AWAY FROM THE LOW LEVEL INSTABILITY SOURCE IN THE NEXT FEW
HOURS. THOUGHT IS AS THIS MOISTURE PUSHES SOUTHWARD AWAY FROM
SOUTHERN LAKE HURON WILL SEE LAKE EFFECT ACTIVITY WANE AFTER 9Z.
REGARDLESS...SNOW SHOWERS REMAIN LIKELY IN THE NEAR TERM WITH
MINOR ACCUMULATIONS POSSIBLE ALONG THE SHORELINE.

DIFFERENTIAL GEOPOTENTIAL HEIGHT REBOUND WILL CAUSE SURFACE HIGH
PRESSURE TO EXPAND AGGRESSIVELY EASTWARD THROUGH THE CWA BY
MIDDAY. LOW TO MIDLEVEL FLOW TRAJECTORIES DEPICT STUBBORN CYCLONIC
FLOW INTO THE LATE AFTERNOON BEFORE EVENTUALLY RELINQUISHING BY
LATE AFTERNOON. THE ARRIVAL OF THE ANTICYCLONIC FLOW WILL PROBABLY
END ANY POTENTIAL FOR CONTINUED LAKE EFFECT CLOUD THAT MAY HANG ON
ACROSS THE EASTERN CWA TODAY. WITH NORTHERLY FLOW FIRMLY IN
CONTROL...WANTED TO HANG CLOSE TO GUIDANCE WITH TEMPERATURES
AROUND 30 TO THE LOW 30S POSSIBLE.

QUIET WEATHER IS FORECASTED TONIGHT WITH HIGH PRESSURE AT THE
SURFACE AND SHORTWAVE RIDGING ALOFT. TEMPERATURES WILL AGAIN BE
COLD WITH READINGS FALLING INTO THE TEENS ACROSS ALL OF THE AREA
(10 TO 15 DEGREES BELOW AVERAGES).

LONG TERM...

SUNDAY WILL START AN ACTIVE PERIOD OF WEATHER CONSISTING OF A SERIES
OF SHORT WAVES MOVING THROUGH THE NORTHERN TIER OF STATES THROUGH
NEXT WEEK. WHILE IT WILL BE ACTIVE IN TERMS OF PRECIPITATION...THERE
WILL BE AN UNDERLYING WARMING TREND THROUGH THE PERIOD. THIS WILL BE
DRIVEN BY AN ENERGETIC PACIFIC UPPER LEVEL JET THAT WILL FORCE A
TRANSITION OUT OF THE LONG WAVE RIDGE OVER THE WEST/TROUGH OVER THE
EAST THAT HAS BEEN SO PERSISTENT AND RESISTANT TO THE ONSET OF
SPRING. THIS LARGE SCALE TRANSITION SUPPORTS GUIDANCE TEMPS OFFERING
HIGHS PUSHING 60 BY THURSDAY.

FIRST THING FIRST IS THE NEXT LOW PRESSURE SYSTEM MOVING THROUGH THE
CENTRAL ROCKIES TODAY ON SCHEDULE TO ARRIVE IN THE GREAT LAKES
SUNDAY. MODEL AGREEMENT REMAINS SOLID IN THE LATEST CYCLE WITH THE
DEPICTION OF MODEST SURFACE LEE CYCLOGENESIS OVER THE NORTHERN
PLAINS AND CANADIAN PRAIRIE...ENOUGH TO DRAW SOME GULF MODIFIED AIR
NORTHWARD TO AUGMENT MID LEVEL PACIFIC MOISTURE AND BRING
PRECIPITATION INTO SE MICHIGAN FROM MID SUNDAY AFTERNOON THROUGH
SUNDAY EVENING. THE DETERMINATION OF PRECIPITATION TYPE REMAINS
COMPLICATED BY STRONG WET BULB COOLING SHOWN IN MODEL SOUNDINGS
OPPOSED BY STRONG LOW LEVEL WARM ADVECTION. THE SAME MODEL SOUNDINGS
INDICATE THE BOUNDARY LAYER GROWING TO ABOUT 900 MB...GOOD ENOUGH
FOR SURFACE WIND GUSTS PUSHING 30 KNOTS...WHICH WILL EASILY CARRY
TEMPERATURES INTO THE LOWER 40S BEFORE THE MOISTURE ARRIVES. THE LOW
LEVEL JET CENTERED AROUND 850 MB WILL ALSO BE PUSHING 60 KNOTS WHICH
WILL BE CAPABLE OF DRIVING THE LOW LEVEL THERMAL RIDGE WELL INTO THE
SAGINAW VALLEY WITH THE ONSET OF PRECIPITATION. THE OVERALL STRENGTH
OF THE SOUTHWEST FLOW IS THEN EXPECTED TO SUPPORT AN ABOVE FREEZING
BOUNDARY LAYER TEMPERATURE PROFILE CLOSE TO 1500 FT DEEP INTO
SURFACE TEMPERATURES IN THE LOWER 40S...SUFFICIENT FOR MELTING TO
RAIN AS LONG AS PRECIPITATION RATE REMAINS AS LOW AS THAT IMPLIED BY
3 HR MODEL QPF AROUND 0.1 INCH.

A QUICK PASSAGE OF THE COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL
OCCUR SUNDAY NIGHT AND BRING A TRANSITION BACK TO SNOW SHOWERS
DURING THE EVENING. SOME LINGERING WRAP-AROUND MOISTURE WITH THE
UPPER WAVE WILL COMBINE WITH THE FRONTAL FORCING TO SUPPORT THE BEST
COVERAGE IN THE SAGINAW VALLEY AND THUMB RESULTING IN A SLUSHY
COATING BEFORE ENDING. COLD ADVECTION TRAILING THE FRONT DURING
MONDAY WILL NOT RESULT IN AS COLD AN AIR MASS AS WE ARE EXPERIENCING
THIS WEEKEND...BUT IT WILL BE ADEQUATE ENOUGH TO SET THE STAGE FOR
PRECIPITATION TYPE QUESTIONS AS THE NEXT SYSTEM ARRIVES MONDAY NIGHT
INTO TUESDAY. THIS ONE WILL BE MERELY A RIPPLE WITHIN THE BAROCLINIC
ZONE LEFT NEARBY TO THE SOUTH AND WEST AND APPEARS FRAUGHT WITH LOW
PREDICTABILITY. THE WAVE WILL BE OPEN ALOFT BUT THE MODELS OFFER A
BROAD RANGE OF SOLUTIONS ON THE DEPTH...TRACK...AND TIMING OF THE
SURFACE LOW/TROUGH. THE 00Z RUNS ARE TRENDING TOWARD A DEEPER
SURFACE WAVE MOVING THROUGH THE SOUTH HALF OF LOWER MICHIGAN LATE
MONDAY NIGHT THROUGH TUESDAY MORNING.

THE TUESDAY WAVE WILL BE THE LAST ONE BEFORE THE NORTHERN STREAM
BEGINS TO LIFT NORTHWARD WEDNESDAY INTO THURSDAY. THIS WILL BE DUE
TO THE LONG WAVE PATTERN SHIFT BEING DRIVEN BY A LARGER PACIFIC LOW
PRESSURE SYSTEM EXPECTED TO MOVE THROUGH CENTRAL CANADA THURSDAY.
GLOBAL MODEL SOLUTIONS INDICATE QUITE A BIT OF SPREAD IN THE UPPER
AIR PATTERN TOWARD THE END OF THE WEEK BUT THE DECREASED LONG WAVE
AMPLIFICATION WILL RESULT IN A MODERATING TEMPERATURE TREND IN
BETWEEN POTENTIAL ROUNDS OF SHOWERS INTO NEXT WEEKEND.

MARINE...

A BROAD AREA OF HIGH PRESSURE WILL SLIDE ACROSS THE GREAT LAKES
TODAY AND BRING FAVORABLE MARINE CONDITIONS THROUGH TONIGHT.
SOUTHWEST WIND WILL THEN INCREASE CONSIDERABLY DURING SUNDAY AS THE
NEXT LOW PRESSURE SYSTEM APPROACHES. GUSTS THROUGH SAGINAW BAY AND
OVER THE OPEN WATERS OF LAKE HURON WILL REACH 30 KNOTS BUT LIKELY
STAY BELOW GALES BEFORE MID LAKE. WARMER AIR MOVING OVER THE COLD
WATER AND REMAINING ICE WILL BE A LIMITING FACTOR DUE TO INCREASED
STABILITY. THE ASSOCIATED COLD FRONT WILL THEN SWEEP THROUGH SUNDAY
NIGHT BUT WILL NOT BRING AS MUCH COLD AIR AS WE HAVE SEEN RECENTLY.
NORTHWEST GUSTS NEAR 30 KNOTS WILL BE CONFINED TO THE NORTH HALF OF
LAKE HURON BEFORE HIGH PRESSURE BUILDS OVER THE REGION MONDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....HLO
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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




000
FXUS63 KDTX 281736
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
136 PM EDT SAT MAR 28 2015


.AVIATION...

NORTHERLY FLOW FROM OFF LAKE HURON HAS CONTINUED TO PROVIDE SCT-BKN
CLOUDS BETWEEN 3000-4000 FEET OVER FAR EASTERN MICHIGAN SO FAR
TODAY. CLOUDS WILL CONTINUE TO THIN/DECREASE AND SHOW A GRADUAL
SHIFT TO THE EAST AS FLOW TURNS MORE WESTERLY THROUGH THE AFTERNOON.
COVERAGE AT THE TERMINALS FOR THE REMAINDER OF TODAY IS EXPECTED TO
REMAIN SCT OR LESS. VFR CONDITIONS ARE THEN EXPECTED OVERNIGHT
BEFORE AN APPROACHING LOW PRESSURE SYSTEM BRINGS A CHANCE FOR RAIN
SHOWERS AND A STOUT INCREASE IN SOUTHERLY WINDS TOMORROW.

FOR DTW...CIGS BETWEEN 3000-4000 FEET WILL CONTINUE TO SCATTER OUT
THROUGH 20Z. BEST CHANCE FOR PRECIPITATION TOMORROW WILL HOLD OFF
UNTIL 21Z.

//DTW THRESHOLD PROBABILITIES...

* NONE

&&

.PREV DISCUSSION...ISSUED 357 AM EDT SAT MAR 28 2015

SHORT TERM...TODAY AND TONIGHT

A COUPLE OF FACTORS HAVE COMBINED TO HELP THE SHORE PARALLEL BAND OF
LIGHT LAKE EFFECT SNOW TO PERSIST ALONG THE SHORELINE OF LAKE HURON
OVERNIGHT. THE FIRST HAS BEEN THE STREAMLINING OF NORTHERLY SURFACE
WIND TRAJECTORIES TO PRODUCE AN AREA OF LOCALIZED CONVERGENCE.
SURFACE OBSERVATIONS HAVE BEEN REPORTING A WESTERLY TRAJECTORY OVER
THE EASTERN HALF OF THE LOWER PENINSULA AND EASTERLY TRAJECTORIES AT
THE SHORELINE...PORT HOPE/SARNIA. STATIC NATURE OF THE BANDING
ON RADAR IN ADDITION TO NEGATIVE LOW LEVEL THETA E LAPSE RATES
AND NEAR SURFACE CONVERGENCE CONTINUING IN MODEL DATA THROUGH 9Z
SUGGESTS THE SNOW SHOWER POTENTIAL HAS ANOTHER 2 TO 4 HOURS. RAP
OUTPUT SUGGESTS THERE IS SOME ORGANIZED SIGNAL TO DEEPER MIDLEVEL
MOISTURE ROTATING CYCLONICALLY AROUND A CENTER POINT OVER THE
EASTERN END OF LAKE ERIE. THIS SUGGESTS THE DEEPER MOISTURE WILL
PIVOT AWAY FROM THE LOW LEVEL INSTABILITY SOURCE IN THE NEXT FEW
HOURS. THOUGHT IS AS THIS MOISTURE PUSHES SOUTHWARD AWAY FROM
SOUTHERN LAKE HURON WILL SEE LAKE EFFECT ACTIVITY WANE AFTER 9Z.
REGARDLESS...SNOW SHOWERS REMAIN LIKELY IN THE NEAR TERM WITH
MINOR ACCUMULATIONS POSSIBLE ALONG THE SHORELINE.

DIFFERENTIAL GEOPOTENTIAL HEIGHT REBOUND WILL CAUSE SURFACE HIGH
PRESSURE TO EXPAND AGGRESSIVELY EASTWARD THROUGH THE CWA BY
MIDDAY. LOW TO MIDLEVEL FLOW TRAJECTORIES DEPICT STUBBORN CYCLONIC
FLOW INTO THE LATE AFTERNOON BEFORE EVENTUALLY RELINQUISHING BY
LATE AFTERNOON. THE ARRIVAL OF THE ANTICYCLONIC FLOW WILL PROBABLY
END ANY POTENTIAL FOR CONTINUED LAKE EFFECT CLOUD THAT MAY HANG ON
ACROSS THE EASTERN CWA TODAY. WITH NORTHERLY FLOW FIRMLY IN
CONTROL...WANTED TO HANG CLOSE TO GUIDANCE WITH TEMPERATURES
AROUND 30 TO THE LOW 30S POSSIBLE.

QUIET WEATHER IS FORECASTED TONIGHT WITH HIGH PRESSURE AT THE
SURFACE AND SHORTWAVE RIDGING ALOFT. TEMPERATURES WILL AGAIN BE
COLD WITH READINGS FALLING INTO THE TEENS ACROSS ALL OF THE AREA
(10 TO 15 DEGREES BELOW AVERAGES).

LONG TERM...

SUNDAY WILL START AN ACTIVE PERIOD OF WEATHER CONSISTING OF A SERIES
OF SHORT WAVES MOVING THROUGH THE NORTHERN TIER OF STATES THROUGH
NEXT WEEK. WHILE IT WILL BE ACTIVE IN TERMS OF PRECIPITATION...THERE
WILL BE AN UNDERLYING WARMING TREND THROUGH THE PERIOD. THIS WILL BE
DRIVEN BY AN ENERGETIC PACIFIC UPPER LEVEL JET THAT WILL FORCE A
TRANSITION OUT OF THE LONG WAVE RIDGE OVER THE WEST/TROUGH OVER THE
EAST THAT HAS BEEN SO PERSISTENT AND RESISTANT TO THE ONSET OF
SPRING. THIS LARGE SCALE TRANSITION SUPPORTS GUIDANCE TEMPS OFFERING
HIGHS PUSHING 60 BY THURSDAY.

FIRST THING FIRST IS THE NEXT LOW PRESSURE SYSTEM MOVING THROUGH THE
CENTRAL ROCKIES TODAY ON SCHEDULE TO ARRIVE IN THE GREAT LAKES
SUNDAY. MODEL AGREEMENT REMAINS SOLID IN THE LATEST CYCLE WITH THE
DEPICTION OF MODEST SURFACE LEE CYCLOGENESIS OVER THE NORTHERN
PLAINS AND CANADIAN PRAIRIE...ENOUGH TO DRAW SOME GULF MODIFIED AIR
NORTHWARD TO AUGMENT MID LEVEL PACIFIC MOISTURE AND BRING
PRECIPITATION INTO SE MICHIGAN FROM MID SUNDAY AFTERNOON THROUGH
SUNDAY EVENING. THE DETERMINATION OF PRECIPITATION TYPE REMAINS
COMPLICATED BY STRONG WET BULB COOLING SHOWN IN MODEL SOUNDINGS
OPPOSED BY STRONG LOW LEVEL WARM ADVECTION. THE SAME MODEL SOUNDINGS
INDICATE THE BOUNDARY LAYER GROWING TO ABOUT 900 MB...GOOD ENOUGH
FOR SURFACE WIND GUSTS PUSHING 30 KNOTS...WHICH WILL EASILY CARRY
TEMPERATURES INTO THE LOWER 40S BEFORE THE MOISTURE ARRIVES. THE LOW
LEVEL JET CENTERED AROUND 850 MB WILL ALSO BE PUSHING 60 KNOTS WHICH
WILL BE CAPABLE OF DRIVING THE LOW LEVEL THERMAL RIDGE WELL INTO THE
SAGINAW VALLEY WITH THE ONSET OF PRECIPITATION. THE OVERALL STRENGTH
OF THE SOUTHWEST FLOW IS THEN EXPECTED TO SUPPORT AN ABOVE FREEZING
BOUNDARY LAYER TEMPERATURE PROFILE CLOSE TO 1500 FT DEEP INTO
SURFACE TEMPERATURES IN THE LOWER 40S...SUFFICIENT FOR MELTING TO
RAIN AS LONG AS PRECIPITATION RATE REMAINS AS LOW AS THAT IMPLIED BY
3 HR MODEL QPF AROUND 0.1 INCH.

A QUICK PASSAGE OF THE COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL
OCCUR SUNDAY NIGHT AND BRING A TRANSITION BACK TO SNOW SHOWERS
DURING THE EVENING. SOME LINGERING WRAP-AROUND MOISTURE WITH THE
UPPER WAVE WILL COMBINE WITH THE FRONTAL FORCING TO SUPPORT THE BEST
COVERAGE IN THE SAGINAW VALLEY AND THUMB RESULTING IN A SLUSHY
COATING BEFORE ENDING. COLD ADVECTION TRAILING THE FRONT DURING
MONDAY WILL NOT RESULT IN AS COLD AN AIR MASS AS WE ARE EXPERIENCING
THIS WEEKEND...BUT IT WILL BE ADEQUATE ENOUGH TO SET THE STAGE FOR
PRECIPITATION TYPE QUESTIONS AS THE NEXT SYSTEM ARRIVES MONDAY NIGHT
INTO TUESDAY. THIS ONE WILL BE MERELY A RIPPLE WITHIN THE BAROCLINIC
ZONE LEFT NEARBY TO THE SOUTH AND WEST AND APPEARS FRAUGHT WITH LOW
PREDICTABILITY. THE WAVE WILL BE OPEN ALOFT BUT THE MODELS OFFER A
BROAD RANGE OF SOLUTIONS ON THE DEPTH...TRACK...AND TIMING OF THE
SURFACE LOW/TROUGH. THE 00Z RUNS ARE TRENDING TOWARD A DEEPER
SURFACE WAVE MOVING THROUGH THE SOUTH HALF OF LOWER MICHIGAN LATE
MONDAY NIGHT THROUGH TUESDAY MORNING.

THE TUESDAY WAVE WILL BE THE LAST ONE BEFORE THE NORTHERN STREAM
BEGINS TO LIFT NORTHWARD WEDNESDAY INTO THURSDAY. THIS WILL BE DUE
TO THE LONG WAVE PATTERN SHIFT BEING DRIVEN BY A LARGER PACIFIC LOW
PRESSURE SYSTEM EXPECTED TO MOVE THROUGH CENTRAL CANADA THURSDAY.
GLOBAL MODEL SOLUTIONS INDICATE QUITE A BIT OF SPREAD IN THE UPPER
AIR PATTERN TOWARD THE END OF THE WEEK BUT THE DECREASED LONG WAVE
AMPLIFICATION WILL RESULT IN A MODERATING TEMPERATURE TREND IN
BETWEEN POTENTIAL ROUNDS OF SHOWERS INTO NEXT WEEKEND.

MARINE...

A BROAD AREA OF HIGH PRESSURE WILL SLIDE ACROSS THE GREAT LAKES
TODAY AND BRING FAVORABLE MARINE CONDITIONS THROUGH TONIGHT.
SOUTHWEST WIND WILL THEN INCREASE CONSIDERABLY DURING SUNDAY AS THE
NEXT LOW PRESSURE SYSTEM APPROACHES. GUSTS THROUGH SAGINAW BAY AND
OVER THE OPEN WATERS OF LAKE HURON WILL REACH 30 KNOTS BUT LIKELY
STAY BELOW GALES BEFORE MID LAKE. WARMER AIR MOVING OVER THE COLD
WATER AND REMAINING ICE WILL BE A LIMITING FACTOR DUE TO INCREASED
STABILITY. THE ASSOCIATED COLD FRONT WILL THEN SWEEP THROUGH SUNDAY
NIGHT BUT WILL NOT BRING AS MUCH COLD AIR AS WE HAVE SEEN RECENTLY.
NORTHWEST GUSTS NEAR 30 KNOTS WILL BE CONFINED TO THE NORTH HALF OF
LAKE HURON BEFORE HIGH PRESSURE BUILDS OVER THE REGION MONDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....HLO
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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





000
FXUS63 KDTX 281103
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
703 AM EDT SAT MAR 28 2015

.AVIATION...

CYCLONIC FLOW WILL PERSIST OVER THE FAR EASTERN SECTIONS OF LOWER
MICHIGAN TODAY WHICH WILL ALLOW REMNANT LAKE STRATOCUMULUS TO
REMAIN IN PLACE. ANTICYCLONIC FLOW TRAJECTORIES WILL FINALLY PUSH
ACROSS THE STATE DURING THE LATE AFTERNOON. DEEP COLUMN RIDGING
WILL THEN BRING CLEAR SKIES TO ALL AREAS FOR TONIGHT.

FOR DTW...BKN CIGS AT LESS THAN 5000 FT WILL IMPACT THE DTW
TERMINALS FOR THE BEGINNING OF THE TAF PERIOD. THERE IS LOW
CONFIDENCE IN SNOW SHOWER ACTIVITY TO IMPACT THE DETROIT TERMINAL.
DEEP COLUMN RIDGING WILL THEN BRING NO POTENTIAL FOR CLOUDS THIS
AFTERNOON AND TONIGHT.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FT THIS MORNING.

&&

.PREV DISCUSSION...ISSUED 357 AM EDT SAT MAR 28 2015

SHORT TERM...TODAY AND TONIGHT

A COUPLE OF FACTORS HAVE COMBINED TO HELP THE SHORE PARALLEL BAND OF
LIGHT LAKE EFFECT SNOW TO PERSIST ALONG THE SHORELINE OF LAKE HURON
OVERNIGHT. THE FIRST HAS BEEN THE STREAMLINING OF NORTHERLY SURFACE
WIND TRAJECTORIES TO PRODUCE AN AREA OF LOCALIZED CONVERGENCE.
SURFACE OBSERVATIONS HAVE BEEN REPORTING A WESTERLY TRAJECTORY OVER
THE EASTERN HALF OF THE LOWER PENINSULA AND EASTERLY TRAJECTORIES AT
THE SHORELINE...PORT HOPE/SARNIA. STATIC NATURE OF THE BANDING
ON RADAR IN ADDITION TO NEGATIVE LOW LEVEL THETA E LAPSE RATES
AND NEAR SURFACE CONVERGENCE CONTINUING IN MODEL DATA THROUGH 9Z
SUGGESTS THE SNOW SHOWER POTENTIAL HAS ANOTHER 2 TO 4 HOURS. RAP
OUTPUT SUGGESTS THERE IS SOME ORGANIZED SIGNAL TO DEEPER MIDLEVEL
MOISTURE ROTATING CYCLONICALLY AROUND A CENTER POINT OVER THE
EASTERN END OF LAKE ERIE. THIS SUGGESTS THE DEEPER MOISTURE WILL
PIVOT AWAY FROM THE LOW LEVEL INSTABILITY SOURCE IN THE NEXT FEW
HOURS. THOUGHT IS AS THIS MOISTURE PUSHES SOUTHWARD AWAY FROM
SOUTHERN LAKE HURON WILL SEE LAKE EFFECT ACTIVITY WANE AFTER 9Z.
REGARDLESS...SNOW SHOWERS REMAIN LIKELY IN THE NEAR TERM WITH
MINOR ACCUMULATIONS POSSIBLE ALONG THE SHORELINE.

DIFFERENTIAL GEOPOTENTIAL HEIGHT REBOUND WILL CAUSE SURFACE HIGH
PRESSURE TO EXPAND AGGRESSIVELY EASTWARD THROUGH THE CWA BY
MIDDAY. LOW TO MIDLEVEL FLOW TRAJECTORIES DEPICT STUBBORN CYCLONIC
FLOW INTO THE LATE AFTERNOON BEFORE EVENTUALLY RELINQUISHING BY
LATE AFTERNOON. THE ARRIVAL OF THE ANTICYCLONIC FLOW WILL PROBABLY
END ANY POTENTIAL FOR CONTINUED LAKE EFFECT CLOUD THAT MAY HANG ON
ACROSS THE EASTERN CWA TODAY. WITH NORTHERLY FLOW FIRMLY IN
CONTROL...WANTED TO HANG CLOSE TO GUIDANCE WITH TEMPERATURES
AROUND 30 TO THE LOW 30S POSSIBLE.

QUIET WEATHER IS FORECASTED TONIGHT WITH HIGH PRESSURE AT THE
SURFACE AND SHORTWAVE RIDGING ALOFT. TEMPERATURES WILL AGAIN BE
COLD WITH READINGS FALLING INTO THE TEENS ACROSS ALL OF THE AREA
(10 TO 15 DEGREES BELOW AVERAGES).

LONG TERM...

SUNDAY WILL START AN ACTIVE PERIOD OF WEATHER CONSISTING OF A SERIES
OF SHORT WAVES MOVING THROUGH THE NORTHERN TIER OF STATES THROUGH
NEXT WEEK. WHILE IT WILL BE ACTIVE IN TERMS OF PRECIPITATION...THERE
WILL BE AN UNDERLYING WARMING TREND THROUGH THE PERIOD. THIS WILL BE
DRIVEN BY AN ENERGETIC PACIFIC UPPER LEVEL JET THAT WILL FORCE A
TRANSITION OUT OF THE LONG WAVE RIDGE OVER THE WEST/TROUGH OVER THE
EAST THAT HAS BEEN SO PERSISTENT AND RESISTANT TO THE ONSET OF
SPRING. THIS LARGE SCALE TRANSITION SUPPORTS GUIDANCE TEMPS OFFERING
HIGHS PUSHING 60 BY THURSDAY.

FIRST THING FIRST IS THE NEXT LOW PRESSURE SYSTEM MOVING THROUGH THE
CENTRAL ROCKIES TODAY ON SCHEDULE TO ARRIVE IN THE GREAT LAKES
SUNDAY. MODEL AGREEMENT REMAINS SOLID IN THE LATEST CYCLE WITH THE
DEPICTION OF MODEST SURFACE LEE CYCLOGENESIS OVER THE NORTHERN
PLAINS AND CANADIAN PRAIRIE...ENOUGH TO DRAW SOME GULF MODIFIED AIR
NORTHWARD TO AUGMENT MID LEVEL PACIFIC MOISTURE AND BRING
PRECIPITATION INTO SE MICHIGAN FROM MID SUNDAY AFTERNOON THROUGH
SUNDAY EVENING. THE DETERMINATION OF PRECIPITATION TYPE REMAINS
COMPLICATED BY STRONG WET BULB COOLING SHOWN IN MODEL SOUNDINGS
OPPOSED BY STRONG LOW LEVEL WARM ADVECTION. THE SAME MODEL SOUNDINGS
INDICATE THE BOUNDARY LAYER GROWING TO ABOUT 900 MB...GOOD ENOUGH
FOR SURFACE WIND GUSTS PUSHING 30 KNOTS...WHICH WILL EASILY CARRY
TEMPERATURES INTO THE LOWER 40S BEFORE THE MOISTURE ARRIVES. THE LOW
LEVEL JET CENTERED AROUND 850 MB WILL ALSO BE PUSHING 60 KNOTS WHICH
WILL BE CAPABLE OF DRIVING THE LOW LEVEL THERMAL RIDGE WELL INTO THE
SAGINAW VALLEY WITH THE ONSET OF PRECIPITATION. THE OVERALL STRENGTH
OF THE SOUTHWEST FLOW IS THEN EXPECTED TO SUPPORT AN ABOVE FREEZING
BOUNDARY LAYER TEMPERATURE PROFILE CLOSE TO 1500 FT DEEP INTO
SURFACE TEMPERATURES IN THE LOWER 40S...SUFFICIENT FOR MELTING TO
RAIN AS LONG AS PRECIPITATION RATE REMAINS AS LOW AS THAT IMPLIED BY
3 HR MODEL QPF AROUND 0.1 INCH.

A QUICK PASSAGE OF THE COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL
OCCUR SUNDAY NIGHT AND BRING A TRANSITION BACK TO SNOW SHOWERS
DURING THE EVENING. SOME LINGERING WRAP-AROUND MOISTURE WITH THE
UPPER WAVE WILL COMBINE WITH THE FRONTAL FORCING TO SUPPORT THE BEST
COVERAGE IN THE SAGINAW VALLEY AND THUMB RESULTING IN A SLUSHY
COATING BEFORE ENDING. COLD ADVECTION TRAILING THE FRONT DURING
MONDAY WILL NOT RESULT IN AS COLD AN AIR MASS AS WE ARE EXPERIENCING
THIS WEEKEND...BUT IT WILL BE ADEQUATE ENOUGH TO SET THE STAGE FOR
PRECIPITATION TYPE QUESTIONS AS THE NEXT SYSTEM ARRIVES MONDAY NIGHT
INTO TUESDAY. THIS ONE WILL BE MERELY A RIPPLE WITHIN THE BAROCLINIC
ZONE LEFT NEARBY TO THE SOUTH AND WEST AND APPEARS FRAUGHT WITH LOW
PREDICTABILITY. THE WAVE WILL BE OPEN ALOFT BUT THE MODELS OFFER A
BROAD RANGE OF SOLUTIONS ON THE DEPTH...TRACK...AND TIMING OF THE
SURFACE LOW/TROUGH. THE 00Z RUNS ARE TRENDING TOWARD A DEEPER
SURFACE WAVE MOVING THROUGH THE SOUTH HALF OF LOWER MICHIGAN LATE
MONDAY NIGHT THROUGH TUESDAY MORNING.

THE TUESDAY WAVE WILL BE THE LAST ONE BEFORE THE NORTHERN STREAM
BEGINS TO LIFT NORTHWARD WEDNESDAY INTO THURSDAY. THIS WILL BE DUE
TO THE LONG WAVE PATTERN SHIFT BEING DRIVEN BY A LARGER PACIFIC LOW
PRESSURE SYSTEM EXPECTED TO MOVE THROUGH CENTRAL CANADA THURSDAY.
GLOBAL MODEL SOLUTIONS INDICATE QUITE A BIT OF SPREAD IN THE UPPER
AIR PATTERN TOWARD THE END OF THE WEEK BUT THE DECREASED LONG WAVE
AMPLIFICATION WILL RESULT IN A MODERATING TEMPERATURE TREND IN
BETWEEN POTENTIAL ROUNDS OF SHOWERS INTO NEXT WEEKEND.

MARINE...

A BROAD AREA OF HIGH PRESSURE WILL SLIDE ACROSS THE GREAT LAKES
TODAY AND BRING FAVORABLE MARINE CONDITIONS THROUGH TONIGHT.
SOUTHWEST WIND WILL THEN INCREASE CONSIDERABLY DURING SUNDAY AS THE
NEXT LOW PRESSURE SYSTEM APPROACHES. GUSTS THROUGH SAGINAW BAY AND
OVER THE OPEN WATERS OF LAKE HURON WILL REACH 30 KNOTS BUT LIKELY
STAY BELOW GALES BEFORE MID LAKE. WARMER AIR MOVING OVER THE COLD
WATER AND REMAINING ICE WILL BE A LIMITING FACTOR DUE TO INCREASED
STABILITY. THE ASSOCIATED COLD FRONT WILL THEN SWEEP THROUGH SUNDAY
NIGHT BUT WILL NOT BRING AS MUCH COLD AIR AS WE HAVE SEEN RECENTLY.
NORTHWEST GUSTS NEAR 30 KNOTS WILL BE CONFINED TO THE NORTH HALF OF
LAKE HURON BEFORE HIGH PRESSURE BUILDS OVER THE REGION MONDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....CB
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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





000
FXUS63 KDTX 281103
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
703 AM EDT SAT MAR 28 2015

.AVIATION...

CYCLONIC FLOW WILL PERSIST OVER THE FAR EASTERN SECTIONS OF LOWER
MICHIGAN TODAY WHICH WILL ALLOW REMNANT LAKE STRATOCUMULUS TO
REMAIN IN PLACE. ANTICYCLONIC FLOW TRAJECTORIES WILL FINALLY PUSH
ACROSS THE STATE DURING THE LATE AFTERNOON. DEEP COLUMN RIDGING
WILL THEN BRING CLEAR SKIES TO ALL AREAS FOR TONIGHT.

FOR DTW...BKN CIGS AT LESS THAN 5000 FT WILL IMPACT THE DTW
TERMINALS FOR THE BEGINNING OF THE TAF PERIOD. THERE IS LOW
CONFIDENCE IN SNOW SHOWER ACTIVITY TO IMPACT THE DETROIT TERMINAL.
DEEP COLUMN RIDGING WILL THEN BRING NO POTENTIAL FOR CLOUDS THIS
AFTERNOON AND TONIGHT.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FT THIS MORNING.

&&

.PREV DISCUSSION...ISSUED 357 AM EDT SAT MAR 28 2015

SHORT TERM...TODAY AND TONIGHT

A COUPLE OF FACTORS HAVE COMBINED TO HELP THE SHORE PARALLEL BAND OF
LIGHT LAKE EFFECT SNOW TO PERSIST ALONG THE SHORELINE OF LAKE HURON
OVERNIGHT. THE FIRST HAS BEEN THE STREAMLINING OF NORTHERLY SURFACE
WIND TRAJECTORIES TO PRODUCE AN AREA OF LOCALIZED CONVERGENCE.
SURFACE OBSERVATIONS HAVE BEEN REPORTING A WESTERLY TRAJECTORY OVER
THE EASTERN HALF OF THE LOWER PENINSULA AND EASTERLY TRAJECTORIES AT
THE SHORELINE...PORT HOPE/SARNIA. STATIC NATURE OF THE BANDING
ON RADAR IN ADDITION TO NEGATIVE LOW LEVEL THETA E LAPSE RATES
AND NEAR SURFACE CONVERGENCE CONTINUING IN MODEL DATA THROUGH 9Z
SUGGESTS THE SNOW SHOWER POTENTIAL HAS ANOTHER 2 TO 4 HOURS. RAP
OUTPUT SUGGESTS THERE IS SOME ORGANIZED SIGNAL TO DEEPER MIDLEVEL
MOISTURE ROTATING CYCLONICALLY AROUND A CENTER POINT OVER THE
EASTERN END OF LAKE ERIE. THIS SUGGESTS THE DEEPER MOISTURE WILL
PIVOT AWAY FROM THE LOW LEVEL INSTABILITY SOURCE IN THE NEXT FEW
HOURS. THOUGHT IS AS THIS MOISTURE PUSHES SOUTHWARD AWAY FROM
SOUTHERN LAKE HURON WILL SEE LAKE EFFECT ACTIVITY WANE AFTER 9Z.
REGARDLESS...SNOW SHOWERS REMAIN LIKELY IN THE NEAR TERM WITH
MINOR ACCUMULATIONS POSSIBLE ALONG THE SHORELINE.

DIFFERENTIAL GEOPOTENTIAL HEIGHT REBOUND WILL CAUSE SURFACE HIGH
PRESSURE TO EXPAND AGGRESSIVELY EASTWARD THROUGH THE CWA BY
MIDDAY. LOW TO MIDLEVEL FLOW TRAJECTORIES DEPICT STUBBORN CYCLONIC
FLOW INTO THE LATE AFTERNOON BEFORE EVENTUALLY RELINQUISHING BY
LATE AFTERNOON. THE ARRIVAL OF THE ANTICYCLONIC FLOW WILL PROBABLY
END ANY POTENTIAL FOR CONTINUED LAKE EFFECT CLOUD THAT MAY HANG ON
ACROSS THE EASTERN CWA TODAY. WITH NORTHERLY FLOW FIRMLY IN
CONTROL...WANTED TO HANG CLOSE TO GUIDANCE WITH TEMPERATURES
AROUND 30 TO THE LOW 30S POSSIBLE.

QUIET WEATHER IS FORECASTED TONIGHT WITH HIGH PRESSURE AT THE
SURFACE AND SHORTWAVE RIDGING ALOFT. TEMPERATURES WILL AGAIN BE
COLD WITH READINGS FALLING INTO THE TEENS ACROSS ALL OF THE AREA
(10 TO 15 DEGREES BELOW AVERAGES).

LONG TERM...

SUNDAY WILL START AN ACTIVE PERIOD OF WEATHER CONSISTING OF A SERIES
OF SHORT WAVES MOVING THROUGH THE NORTHERN TIER OF STATES THROUGH
NEXT WEEK. WHILE IT WILL BE ACTIVE IN TERMS OF PRECIPITATION...THERE
WILL BE AN UNDERLYING WARMING TREND THROUGH THE PERIOD. THIS WILL BE
DRIVEN BY AN ENERGETIC PACIFIC UPPER LEVEL JET THAT WILL FORCE A
TRANSITION OUT OF THE LONG WAVE RIDGE OVER THE WEST/TROUGH OVER THE
EAST THAT HAS BEEN SO PERSISTENT AND RESISTANT TO THE ONSET OF
SPRING. THIS LARGE SCALE TRANSITION SUPPORTS GUIDANCE TEMPS OFFERING
HIGHS PUSHING 60 BY THURSDAY.

FIRST THING FIRST IS THE NEXT LOW PRESSURE SYSTEM MOVING THROUGH THE
CENTRAL ROCKIES TODAY ON SCHEDULE TO ARRIVE IN THE GREAT LAKES
SUNDAY. MODEL AGREEMENT REMAINS SOLID IN THE LATEST CYCLE WITH THE
DEPICTION OF MODEST SURFACE LEE CYCLOGENESIS OVER THE NORTHERN
PLAINS AND CANADIAN PRAIRIE...ENOUGH TO DRAW SOME GULF MODIFIED AIR
NORTHWARD TO AUGMENT MID LEVEL PACIFIC MOISTURE AND BRING
PRECIPITATION INTO SE MICHIGAN FROM MID SUNDAY AFTERNOON THROUGH
SUNDAY EVENING. THE DETERMINATION OF PRECIPITATION TYPE REMAINS
COMPLICATED BY STRONG WET BULB COOLING SHOWN IN MODEL SOUNDINGS
OPPOSED BY STRONG LOW LEVEL WARM ADVECTION. THE SAME MODEL SOUNDINGS
INDICATE THE BOUNDARY LAYER GROWING TO ABOUT 900 MB...GOOD ENOUGH
FOR SURFACE WIND GUSTS PUSHING 30 KNOTS...WHICH WILL EASILY CARRY
TEMPERATURES INTO THE LOWER 40S BEFORE THE MOISTURE ARRIVES. THE LOW
LEVEL JET CENTERED AROUND 850 MB WILL ALSO BE PUSHING 60 KNOTS WHICH
WILL BE CAPABLE OF DRIVING THE LOW LEVEL THERMAL RIDGE WELL INTO THE
SAGINAW VALLEY WITH THE ONSET OF PRECIPITATION. THE OVERALL STRENGTH
OF THE SOUTHWEST FLOW IS THEN EXPECTED TO SUPPORT AN ABOVE FREEZING
BOUNDARY LAYER TEMPERATURE PROFILE CLOSE TO 1500 FT DEEP INTO
SURFACE TEMPERATURES IN THE LOWER 40S...SUFFICIENT FOR MELTING TO
RAIN AS LONG AS PRECIPITATION RATE REMAINS AS LOW AS THAT IMPLIED BY
3 HR MODEL QPF AROUND 0.1 INCH.

A QUICK PASSAGE OF THE COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL
OCCUR SUNDAY NIGHT AND BRING A TRANSITION BACK TO SNOW SHOWERS
DURING THE EVENING. SOME LINGERING WRAP-AROUND MOISTURE WITH THE
UPPER WAVE WILL COMBINE WITH THE FRONTAL FORCING TO SUPPORT THE BEST
COVERAGE IN THE SAGINAW VALLEY AND THUMB RESULTING IN A SLUSHY
COATING BEFORE ENDING. COLD ADVECTION TRAILING THE FRONT DURING
MONDAY WILL NOT RESULT IN AS COLD AN AIR MASS AS WE ARE EXPERIENCING
THIS WEEKEND...BUT IT WILL BE ADEQUATE ENOUGH TO SET THE STAGE FOR
PRECIPITATION TYPE QUESTIONS AS THE NEXT SYSTEM ARRIVES MONDAY NIGHT
INTO TUESDAY. THIS ONE WILL BE MERELY A RIPPLE WITHIN THE BAROCLINIC
ZONE LEFT NEARBY TO THE SOUTH AND WEST AND APPEARS FRAUGHT WITH LOW
PREDICTABILITY. THE WAVE WILL BE OPEN ALOFT BUT THE MODELS OFFER A
BROAD RANGE OF SOLUTIONS ON THE DEPTH...TRACK...AND TIMING OF THE
SURFACE LOW/TROUGH. THE 00Z RUNS ARE TRENDING TOWARD A DEEPER
SURFACE WAVE MOVING THROUGH THE SOUTH HALF OF LOWER MICHIGAN LATE
MONDAY NIGHT THROUGH TUESDAY MORNING.

THE TUESDAY WAVE WILL BE THE LAST ONE BEFORE THE NORTHERN STREAM
BEGINS TO LIFT NORTHWARD WEDNESDAY INTO THURSDAY. THIS WILL BE DUE
TO THE LONG WAVE PATTERN SHIFT BEING DRIVEN BY A LARGER PACIFIC LOW
PRESSURE SYSTEM EXPECTED TO MOVE THROUGH CENTRAL CANADA THURSDAY.
GLOBAL MODEL SOLUTIONS INDICATE QUITE A BIT OF SPREAD IN THE UPPER
AIR PATTERN TOWARD THE END OF THE WEEK BUT THE DECREASED LONG WAVE
AMPLIFICATION WILL RESULT IN A MODERATING TEMPERATURE TREND IN
BETWEEN POTENTIAL ROUNDS OF SHOWERS INTO NEXT WEEKEND.

MARINE...

A BROAD AREA OF HIGH PRESSURE WILL SLIDE ACROSS THE GREAT LAKES
TODAY AND BRING FAVORABLE MARINE CONDITIONS THROUGH TONIGHT.
SOUTHWEST WIND WILL THEN INCREASE CONSIDERABLY DURING SUNDAY AS THE
NEXT LOW PRESSURE SYSTEM APPROACHES. GUSTS THROUGH SAGINAW BAY AND
OVER THE OPEN WATERS OF LAKE HURON WILL REACH 30 KNOTS BUT LIKELY
STAY BELOW GALES BEFORE MID LAKE. WARMER AIR MOVING OVER THE COLD
WATER AND REMAINING ICE WILL BE A LIMITING FACTOR DUE TO INCREASED
STABILITY. THE ASSOCIATED COLD FRONT WILL THEN SWEEP THROUGH SUNDAY
NIGHT BUT WILL NOT BRING AS MUCH COLD AIR AS WE HAVE SEEN RECENTLY.
NORTHWEST GUSTS NEAR 30 KNOTS WILL BE CONFINED TO THE NORTH HALF OF
LAKE HURON BEFORE HIGH PRESSURE BUILDS OVER THE REGION MONDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....CB
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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




000
FXUS63 KDTX 281103
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
703 AM EDT SAT MAR 28 2015

.AVIATION...

CYCLONIC FLOW WILL PERSIST OVER THE FAR EASTERN SECTIONS OF LOWER
MICHIGAN TODAY WHICH WILL ALLOW REMNANT LAKE STRATOCUMULUS TO
REMAIN IN PLACE. ANTICYCLONIC FLOW TRAJECTORIES WILL FINALLY PUSH
ACROSS THE STATE DURING THE LATE AFTERNOON. DEEP COLUMN RIDGING
WILL THEN BRING CLEAR SKIES TO ALL AREAS FOR TONIGHT.

FOR DTW...BKN CIGS AT LESS THAN 5000 FT WILL IMPACT THE DTW
TERMINALS FOR THE BEGINNING OF THE TAF PERIOD. THERE IS LOW
CONFIDENCE IN SNOW SHOWER ACTIVITY TO IMPACT THE DETROIT TERMINAL.
DEEP COLUMN RIDGING WILL THEN BRING NO POTENTIAL FOR CLOUDS THIS
AFTERNOON AND TONIGHT.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FT THIS MORNING.

&&

.PREV DISCUSSION...ISSUED 357 AM EDT SAT MAR 28 2015

SHORT TERM...TODAY AND TONIGHT

A COUPLE OF FACTORS HAVE COMBINED TO HELP THE SHORE PARALLEL BAND OF
LIGHT LAKE EFFECT SNOW TO PERSIST ALONG THE SHORELINE OF LAKE HURON
OVERNIGHT. THE FIRST HAS BEEN THE STREAMLINING OF NORTHERLY SURFACE
WIND TRAJECTORIES TO PRODUCE AN AREA OF LOCALIZED CONVERGENCE.
SURFACE OBSERVATIONS HAVE BEEN REPORTING A WESTERLY TRAJECTORY OVER
THE EASTERN HALF OF THE LOWER PENINSULA AND EASTERLY TRAJECTORIES AT
THE SHORELINE...PORT HOPE/SARNIA. STATIC NATURE OF THE BANDING
ON RADAR IN ADDITION TO NEGATIVE LOW LEVEL THETA E LAPSE RATES
AND NEAR SURFACE CONVERGENCE CONTINUING IN MODEL DATA THROUGH 9Z
SUGGESTS THE SNOW SHOWER POTENTIAL HAS ANOTHER 2 TO 4 HOURS. RAP
OUTPUT SUGGESTS THERE IS SOME ORGANIZED SIGNAL TO DEEPER MIDLEVEL
MOISTURE ROTATING CYCLONICALLY AROUND A CENTER POINT OVER THE
EASTERN END OF LAKE ERIE. THIS SUGGESTS THE DEEPER MOISTURE WILL
PIVOT AWAY FROM THE LOW LEVEL INSTABILITY SOURCE IN THE NEXT FEW
HOURS. THOUGHT IS AS THIS MOISTURE PUSHES SOUTHWARD AWAY FROM
SOUTHERN LAKE HURON WILL SEE LAKE EFFECT ACTIVITY WANE AFTER 9Z.
REGARDLESS...SNOW SHOWERS REMAIN LIKELY IN THE NEAR TERM WITH
MINOR ACCUMULATIONS POSSIBLE ALONG THE SHORELINE.

DIFFERENTIAL GEOPOTENTIAL HEIGHT REBOUND WILL CAUSE SURFACE HIGH
PRESSURE TO EXPAND AGGRESSIVELY EASTWARD THROUGH THE CWA BY
MIDDAY. LOW TO MIDLEVEL FLOW TRAJECTORIES DEPICT STUBBORN CYCLONIC
FLOW INTO THE LATE AFTERNOON BEFORE EVENTUALLY RELINQUISHING BY
LATE AFTERNOON. THE ARRIVAL OF THE ANTICYCLONIC FLOW WILL PROBABLY
END ANY POTENTIAL FOR CONTINUED LAKE EFFECT CLOUD THAT MAY HANG ON
ACROSS THE EASTERN CWA TODAY. WITH NORTHERLY FLOW FIRMLY IN
CONTROL...WANTED TO HANG CLOSE TO GUIDANCE WITH TEMPERATURES
AROUND 30 TO THE LOW 30S POSSIBLE.

QUIET WEATHER IS FORECASTED TONIGHT WITH HIGH PRESSURE AT THE
SURFACE AND SHORTWAVE RIDGING ALOFT. TEMPERATURES WILL AGAIN BE
COLD WITH READINGS FALLING INTO THE TEENS ACROSS ALL OF THE AREA
(10 TO 15 DEGREES BELOW AVERAGES).

LONG TERM...

SUNDAY WILL START AN ACTIVE PERIOD OF WEATHER CONSISTING OF A SERIES
OF SHORT WAVES MOVING THROUGH THE NORTHERN TIER OF STATES THROUGH
NEXT WEEK. WHILE IT WILL BE ACTIVE IN TERMS OF PRECIPITATION...THERE
WILL BE AN UNDERLYING WARMING TREND THROUGH THE PERIOD. THIS WILL BE
DRIVEN BY AN ENERGETIC PACIFIC UPPER LEVEL JET THAT WILL FORCE A
TRANSITION OUT OF THE LONG WAVE RIDGE OVER THE WEST/TROUGH OVER THE
EAST THAT HAS BEEN SO PERSISTENT AND RESISTANT TO THE ONSET OF
SPRING. THIS LARGE SCALE TRANSITION SUPPORTS GUIDANCE TEMPS OFFERING
HIGHS PUSHING 60 BY THURSDAY.

FIRST THING FIRST IS THE NEXT LOW PRESSURE SYSTEM MOVING THROUGH THE
CENTRAL ROCKIES TODAY ON SCHEDULE TO ARRIVE IN THE GREAT LAKES
SUNDAY. MODEL AGREEMENT REMAINS SOLID IN THE LATEST CYCLE WITH THE
DEPICTION OF MODEST SURFACE LEE CYCLOGENESIS OVER THE NORTHERN
PLAINS AND CANADIAN PRAIRIE...ENOUGH TO DRAW SOME GULF MODIFIED AIR
NORTHWARD TO AUGMENT MID LEVEL PACIFIC MOISTURE AND BRING
PRECIPITATION INTO SE MICHIGAN FROM MID SUNDAY AFTERNOON THROUGH
SUNDAY EVENING. THE DETERMINATION OF PRECIPITATION TYPE REMAINS
COMPLICATED BY STRONG WET BULB COOLING SHOWN IN MODEL SOUNDINGS
OPPOSED BY STRONG LOW LEVEL WARM ADVECTION. THE SAME MODEL SOUNDINGS
INDICATE THE BOUNDARY LAYER GROWING TO ABOUT 900 MB...GOOD ENOUGH
FOR SURFACE WIND GUSTS PUSHING 30 KNOTS...WHICH WILL EASILY CARRY
TEMPERATURES INTO THE LOWER 40S BEFORE THE MOISTURE ARRIVES. THE LOW
LEVEL JET CENTERED AROUND 850 MB WILL ALSO BE PUSHING 60 KNOTS WHICH
WILL BE CAPABLE OF DRIVING THE LOW LEVEL THERMAL RIDGE WELL INTO THE
SAGINAW VALLEY WITH THE ONSET OF PRECIPITATION. THE OVERALL STRENGTH
OF THE SOUTHWEST FLOW IS THEN EXPECTED TO SUPPORT AN ABOVE FREEZING
BOUNDARY LAYER TEMPERATURE PROFILE CLOSE TO 1500 FT DEEP INTO
SURFACE TEMPERATURES IN THE LOWER 40S...SUFFICIENT FOR MELTING TO
RAIN AS LONG AS PRECIPITATION RATE REMAINS AS LOW AS THAT IMPLIED BY
3 HR MODEL QPF AROUND 0.1 INCH.

A QUICK PASSAGE OF THE COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL
OCCUR SUNDAY NIGHT AND BRING A TRANSITION BACK TO SNOW SHOWERS
DURING THE EVENING. SOME LINGERING WRAP-AROUND MOISTURE WITH THE
UPPER WAVE WILL COMBINE WITH THE FRONTAL FORCING TO SUPPORT THE BEST
COVERAGE IN THE SAGINAW VALLEY AND THUMB RESULTING IN A SLUSHY
COATING BEFORE ENDING. COLD ADVECTION TRAILING THE FRONT DURING
MONDAY WILL NOT RESULT IN AS COLD AN AIR MASS AS WE ARE EXPERIENCING
THIS WEEKEND...BUT IT WILL BE ADEQUATE ENOUGH TO SET THE STAGE FOR
PRECIPITATION TYPE QUESTIONS AS THE NEXT SYSTEM ARRIVES MONDAY NIGHT
INTO TUESDAY. THIS ONE WILL BE MERELY A RIPPLE WITHIN THE BAROCLINIC
ZONE LEFT NEARBY TO THE SOUTH AND WEST AND APPEARS FRAUGHT WITH LOW
PREDICTABILITY. THE WAVE WILL BE OPEN ALOFT BUT THE MODELS OFFER A
BROAD RANGE OF SOLUTIONS ON THE DEPTH...TRACK...AND TIMING OF THE
SURFACE LOW/TROUGH. THE 00Z RUNS ARE TRENDING TOWARD A DEEPER
SURFACE WAVE MOVING THROUGH THE SOUTH HALF OF LOWER MICHIGAN LATE
MONDAY NIGHT THROUGH TUESDAY MORNING.

THE TUESDAY WAVE WILL BE THE LAST ONE BEFORE THE NORTHERN STREAM
BEGINS TO LIFT NORTHWARD WEDNESDAY INTO THURSDAY. THIS WILL BE DUE
TO THE LONG WAVE PATTERN SHIFT BEING DRIVEN BY A LARGER PACIFIC LOW
PRESSURE SYSTEM EXPECTED TO MOVE THROUGH CENTRAL CANADA THURSDAY.
GLOBAL MODEL SOLUTIONS INDICATE QUITE A BIT OF SPREAD IN THE UPPER
AIR PATTERN TOWARD THE END OF THE WEEK BUT THE DECREASED LONG WAVE
AMPLIFICATION WILL RESULT IN A MODERATING TEMPERATURE TREND IN
BETWEEN POTENTIAL ROUNDS OF SHOWERS INTO NEXT WEEKEND.

MARINE...

A BROAD AREA OF HIGH PRESSURE WILL SLIDE ACROSS THE GREAT LAKES
TODAY AND BRING FAVORABLE MARINE CONDITIONS THROUGH TONIGHT.
SOUTHWEST WIND WILL THEN INCREASE CONSIDERABLY DURING SUNDAY AS THE
NEXT LOW PRESSURE SYSTEM APPROACHES. GUSTS THROUGH SAGINAW BAY AND
OVER THE OPEN WATERS OF LAKE HURON WILL REACH 30 KNOTS BUT LIKELY
STAY BELOW GALES BEFORE MID LAKE. WARMER AIR MOVING OVER THE COLD
WATER AND REMAINING ICE WILL BE A LIMITING FACTOR DUE TO INCREASED
STABILITY. THE ASSOCIATED COLD FRONT WILL THEN SWEEP THROUGH SUNDAY
NIGHT BUT WILL NOT BRING AS MUCH COLD AIR AS WE HAVE SEEN RECENTLY.
NORTHWEST GUSTS NEAR 30 KNOTS WILL BE CONFINED TO THE NORTH HALF OF
LAKE HURON BEFORE HIGH PRESSURE BUILDS OVER THE REGION MONDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....CB
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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




000
FXUS63 KDTX 281103
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
703 AM EDT SAT MAR 28 2015

.AVIATION...

CYCLONIC FLOW WILL PERSIST OVER THE FAR EASTERN SECTIONS OF LOWER
MICHIGAN TODAY WHICH WILL ALLOW REMNANT LAKE STRATOCUMULUS TO
REMAIN IN PLACE. ANTICYCLONIC FLOW TRAJECTORIES WILL FINALLY PUSH
ACROSS THE STATE DURING THE LATE AFTERNOON. DEEP COLUMN RIDGING
WILL THEN BRING CLEAR SKIES TO ALL AREAS FOR TONIGHT.

FOR DTW...BKN CIGS AT LESS THAN 5000 FT WILL IMPACT THE DTW
TERMINALS FOR THE BEGINNING OF THE TAF PERIOD. THERE IS LOW
CONFIDENCE IN SNOW SHOWER ACTIVITY TO IMPACT THE DETROIT TERMINAL.
DEEP COLUMN RIDGING WILL THEN BRING NO POTENTIAL FOR CLOUDS THIS
AFTERNOON AND TONIGHT.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FT THIS MORNING.

&&

.PREV DISCUSSION...ISSUED 357 AM EDT SAT MAR 28 2015

SHORT TERM...TODAY AND TONIGHT

A COUPLE OF FACTORS HAVE COMBINED TO HELP THE SHORE PARALLEL BAND OF
LIGHT LAKE EFFECT SNOW TO PERSIST ALONG THE SHORELINE OF LAKE HURON
OVERNIGHT. THE FIRST HAS BEEN THE STREAMLINING OF NORTHERLY SURFACE
WIND TRAJECTORIES TO PRODUCE AN AREA OF LOCALIZED CONVERGENCE.
SURFACE OBSERVATIONS HAVE BEEN REPORTING A WESTERLY TRAJECTORY OVER
THE EASTERN HALF OF THE LOWER PENINSULA AND EASTERLY TRAJECTORIES AT
THE SHORELINE...PORT HOPE/SARNIA. STATIC NATURE OF THE BANDING
ON RADAR IN ADDITION TO NEGATIVE LOW LEVEL THETA E LAPSE RATES
AND NEAR SURFACE CONVERGENCE CONTINUING IN MODEL DATA THROUGH 9Z
SUGGESTS THE SNOW SHOWER POTENTIAL HAS ANOTHER 2 TO 4 HOURS. RAP
OUTPUT SUGGESTS THERE IS SOME ORGANIZED SIGNAL TO DEEPER MIDLEVEL
MOISTURE ROTATING CYCLONICALLY AROUND A CENTER POINT OVER THE
EASTERN END OF LAKE ERIE. THIS SUGGESTS THE DEEPER MOISTURE WILL
PIVOT AWAY FROM THE LOW LEVEL INSTABILITY SOURCE IN THE NEXT FEW
HOURS. THOUGHT IS AS THIS MOISTURE PUSHES SOUTHWARD AWAY FROM
SOUTHERN LAKE HURON WILL SEE LAKE EFFECT ACTIVITY WANE AFTER 9Z.
REGARDLESS...SNOW SHOWERS REMAIN LIKELY IN THE NEAR TERM WITH
MINOR ACCUMULATIONS POSSIBLE ALONG THE SHORELINE.

DIFFERENTIAL GEOPOTENTIAL HEIGHT REBOUND WILL CAUSE SURFACE HIGH
PRESSURE TO EXPAND AGGRESSIVELY EASTWARD THROUGH THE CWA BY
MIDDAY. LOW TO MIDLEVEL FLOW TRAJECTORIES DEPICT STUBBORN CYCLONIC
FLOW INTO THE LATE AFTERNOON BEFORE EVENTUALLY RELINQUISHING BY
LATE AFTERNOON. THE ARRIVAL OF THE ANTICYCLONIC FLOW WILL PROBABLY
END ANY POTENTIAL FOR CONTINUED LAKE EFFECT CLOUD THAT MAY HANG ON
ACROSS THE EASTERN CWA TODAY. WITH NORTHERLY FLOW FIRMLY IN
CONTROL...WANTED TO HANG CLOSE TO GUIDANCE WITH TEMPERATURES
AROUND 30 TO THE LOW 30S POSSIBLE.

QUIET WEATHER IS FORECASTED TONIGHT WITH HIGH PRESSURE AT THE
SURFACE AND SHORTWAVE RIDGING ALOFT. TEMPERATURES WILL AGAIN BE
COLD WITH READINGS FALLING INTO THE TEENS ACROSS ALL OF THE AREA
(10 TO 15 DEGREES BELOW AVERAGES).

LONG TERM...

SUNDAY WILL START AN ACTIVE PERIOD OF WEATHER CONSISTING OF A SERIES
OF SHORT WAVES MOVING THROUGH THE NORTHERN TIER OF STATES THROUGH
NEXT WEEK. WHILE IT WILL BE ACTIVE IN TERMS OF PRECIPITATION...THERE
WILL BE AN UNDERLYING WARMING TREND THROUGH THE PERIOD. THIS WILL BE
DRIVEN BY AN ENERGETIC PACIFIC UPPER LEVEL JET THAT WILL FORCE A
TRANSITION OUT OF THE LONG WAVE RIDGE OVER THE WEST/TROUGH OVER THE
EAST THAT HAS BEEN SO PERSISTENT AND RESISTANT TO THE ONSET OF
SPRING. THIS LARGE SCALE TRANSITION SUPPORTS GUIDANCE TEMPS OFFERING
HIGHS PUSHING 60 BY THURSDAY.

FIRST THING FIRST IS THE NEXT LOW PRESSURE SYSTEM MOVING THROUGH THE
CENTRAL ROCKIES TODAY ON SCHEDULE TO ARRIVE IN THE GREAT LAKES
SUNDAY. MODEL AGREEMENT REMAINS SOLID IN THE LATEST CYCLE WITH THE
DEPICTION OF MODEST SURFACE LEE CYCLOGENESIS OVER THE NORTHERN
PLAINS AND CANADIAN PRAIRIE...ENOUGH TO DRAW SOME GULF MODIFIED AIR
NORTHWARD TO AUGMENT MID LEVEL PACIFIC MOISTURE AND BRING
PRECIPITATION INTO SE MICHIGAN FROM MID SUNDAY AFTERNOON THROUGH
SUNDAY EVENING. THE DETERMINATION OF PRECIPITATION TYPE REMAINS
COMPLICATED BY STRONG WET BULB COOLING SHOWN IN MODEL SOUNDINGS
OPPOSED BY STRONG LOW LEVEL WARM ADVECTION. THE SAME MODEL SOUNDINGS
INDICATE THE BOUNDARY LAYER GROWING TO ABOUT 900 MB...GOOD ENOUGH
FOR SURFACE WIND GUSTS PUSHING 30 KNOTS...WHICH WILL EASILY CARRY
TEMPERATURES INTO THE LOWER 40S BEFORE THE MOISTURE ARRIVES. THE LOW
LEVEL JET CENTERED AROUND 850 MB WILL ALSO BE PUSHING 60 KNOTS WHICH
WILL BE CAPABLE OF DRIVING THE LOW LEVEL THERMAL RIDGE WELL INTO THE
SAGINAW VALLEY WITH THE ONSET OF PRECIPITATION. THE OVERALL STRENGTH
OF THE SOUTHWEST FLOW IS THEN EXPECTED TO SUPPORT AN ABOVE FREEZING
BOUNDARY LAYER TEMPERATURE PROFILE CLOSE TO 1500 FT DEEP INTO
SURFACE TEMPERATURES IN THE LOWER 40S...SUFFICIENT FOR MELTING TO
RAIN AS LONG AS PRECIPITATION RATE REMAINS AS LOW AS THAT IMPLIED BY
3 HR MODEL QPF AROUND 0.1 INCH.

A QUICK PASSAGE OF THE COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL
OCCUR SUNDAY NIGHT AND BRING A TRANSITION BACK TO SNOW SHOWERS
DURING THE EVENING. SOME LINGERING WRAP-AROUND MOISTURE WITH THE
UPPER WAVE WILL COMBINE WITH THE FRONTAL FORCING TO SUPPORT THE BEST
COVERAGE IN THE SAGINAW VALLEY AND THUMB RESULTING IN A SLUSHY
COATING BEFORE ENDING. COLD ADVECTION TRAILING THE FRONT DURING
MONDAY WILL NOT RESULT IN AS COLD AN AIR MASS AS WE ARE EXPERIENCING
THIS WEEKEND...BUT IT WILL BE ADEQUATE ENOUGH TO SET THE STAGE FOR
PRECIPITATION TYPE QUESTIONS AS THE NEXT SYSTEM ARRIVES MONDAY NIGHT
INTO TUESDAY. THIS ONE WILL BE MERELY A RIPPLE WITHIN THE BAROCLINIC
ZONE LEFT NEARBY TO THE SOUTH AND WEST AND APPEARS FRAUGHT WITH LOW
PREDICTABILITY. THE WAVE WILL BE OPEN ALOFT BUT THE MODELS OFFER A
BROAD RANGE OF SOLUTIONS ON THE DEPTH...TRACK...AND TIMING OF THE
SURFACE LOW/TROUGH. THE 00Z RUNS ARE TRENDING TOWARD A DEEPER
SURFACE WAVE MOVING THROUGH THE SOUTH HALF OF LOWER MICHIGAN LATE
MONDAY NIGHT THROUGH TUESDAY MORNING.

THE TUESDAY WAVE WILL BE THE LAST ONE BEFORE THE NORTHERN STREAM
BEGINS TO LIFT NORTHWARD WEDNESDAY INTO THURSDAY. THIS WILL BE DUE
TO THE LONG WAVE PATTERN SHIFT BEING DRIVEN BY A LARGER PACIFIC LOW
PRESSURE SYSTEM EXPECTED TO MOVE THROUGH CENTRAL CANADA THURSDAY.
GLOBAL MODEL SOLUTIONS INDICATE QUITE A BIT OF SPREAD IN THE UPPER
AIR PATTERN TOWARD THE END OF THE WEEK BUT THE DECREASED LONG WAVE
AMPLIFICATION WILL RESULT IN A MODERATING TEMPERATURE TREND IN
BETWEEN POTENTIAL ROUNDS OF SHOWERS INTO NEXT WEEKEND.

MARINE...

A BROAD AREA OF HIGH PRESSURE WILL SLIDE ACROSS THE GREAT LAKES
TODAY AND BRING FAVORABLE MARINE CONDITIONS THROUGH TONIGHT.
SOUTHWEST WIND WILL THEN INCREASE CONSIDERABLY DURING SUNDAY AS THE
NEXT LOW PRESSURE SYSTEM APPROACHES. GUSTS THROUGH SAGINAW BAY AND
OVER THE OPEN WATERS OF LAKE HURON WILL REACH 30 KNOTS BUT LIKELY
STAY BELOW GALES BEFORE MID LAKE. WARMER AIR MOVING OVER THE COLD
WATER AND REMAINING ICE WILL BE A LIMITING FACTOR DUE TO INCREASED
STABILITY. THE ASSOCIATED COLD FRONT WILL THEN SWEEP THROUGH SUNDAY
NIGHT BUT WILL NOT BRING AS MUCH COLD AIR AS WE HAVE SEEN RECENTLY.
NORTHWEST GUSTS NEAR 30 KNOTS WILL BE CONFINED TO THE NORTH HALF OF
LAKE HURON BEFORE HIGH PRESSURE BUILDS OVER THE REGION MONDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....CB
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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





000
FXUS63 KDTX 280757
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
357 AM EDT SAT MAR 28 2015

.SHORT TERM...TODAY AND TONIGHT

A COUPLE OF FACTORS HAVE COMBINED TO HELP THE SHORE PARALLEL BAND OF
LIGHT LAKE EFFECT SNOW TO PERSIST ALONG THE SHORELINE OF LAKE HURON
OVERNIGHT. THE FIRST HAS BEEN THE STREAMLINING OF NORTHERLY SURFACE
WIND TRAJECTORIES TO PRODUCE AN AREA OF LOCALIZED CONVERGENCE.
SURFACE OBSERVATIONS HAVE BEEN REPORTING A WESTERLY TRAJECTORY OVER
THE EASTERN HALF OF THE LOWER PENINSULA AND EASTERLY TRAJECTORIES AT
THE SHORELINE...PORT HOPE/SARNIA. STATIC NATURE OF THE BANDING
ON RADAR IN ADDITION TO NEGATIVE LOW LEVEL THETA E LAPSE RATES
AND NEAR SURFACE CONVERGENCE CONTINUING IN MODEL DATA THROUGH 9Z
SUGGESTS THE SNOW SHOWER POTENTIAL HAS ANOTHER 2 TO 4 HOURS. RAP
OUTPUT SUGGESTS THERE IS SOME ORGANIZED SIGNAL TO DEEPER MIDLEVEL
MOISTURE ROTATING CYCLONICALLY AROUND A CENTER POINT OVER THE
EASTERN END OF LAKE ERIE. THIS SUGGESTS THE
DEEPER MOISTURE WILL PIVOT AWAY FROM THE LOW LEVEL INSTABILITY
SOURCE IN THE NEXT FEW HOURS. THOUGHT IS AS THIS MOISTURE PUSHES
SOUTHWARD AWAY FROM SOUTHERN LAKE HURON WILL SEE LAKE EFFECT
ACTIVITY WANE AFTER 9Z. REGARDLESS...SNOW SHOWERS REMAIN LIKELY IN
THE NEAR TERM WITH MINOR ACCUMULATIONS POSSIBLE ALONG THE SHORELINE.

DIFFERENTIAL GEOPOTENTIAL HEIGHT REBOUND WILL CAUSE SURFACE HIGH
PRESSURE TO EXPAND AGGRESIVELY EASTWARD THROUGH THE CWA BY MIDDAY.
LOW TO MIDLEVEL FLOW TRAJECTORIES DEPICT STUBBORN CYCLONIC FLOW INTO
THE LATE AFTERNOON BEFORE EVENTUALLY RELINQUISHING BY LATE
AFTERNOON. THE ARRIVAL OF THE ANTICYCLONIC FLOW WILL PROBABLY END
ANY POTENTIAL FOR CONTINUED LAKE EFFECT CLOUD THAT MAY HANG ON
ACROSS THE EASTERN CWA TODAY. WITH NORTHERLY FLOW FIRMLY IN
CONTROL...WANTED TO HANG CLOSE TO GUIDANCE WITH TEMPERATURES AROUND
30 TO THE LOW 30S POSSIBLE.

QUIET WEATHER IS FORECASTED TONIGHT WITH HIGH PRESSURE AT THE
SURFACE AND SHORTWAVE RIDGING ALOFT. TEMEPRATURES WILL AGAIN BE COLD
WITH READINGS FALLING INTO THE TEENS ACROSS ALL OF THE AREA (10 TO
15 DEGREES BELOW AVERAGES).

&&

.LONG TERM...

SUNDAY WILL START AN ACTIVE PERIOD OF WEATHER CONSISTING OF A SERIES
OF SHORT WAVES MOVING THROUGH THE NORTHERN TIER OF STATES THROUGH
NEXT WEEK. WHILE IT WILL BE ACTIVE IN TERMS OF PRECIPITATION...THERE
WILL BE AN UNDERLYING WARMING TREND THROUGH THE PERIOD. THIS WILL BE
DRIVEN BY AN ENERGETIC PACIFIC UPPER LEVEL JET THAT WILL FORCE A
TRANSITION OUT OF THE LONG WAVE RIDGE OVER THE WEST/TROUGH OVER THE
EAST THAT HAS BEEN SO PERSISTENT AND RESISTANT TO THE ONSET OF
SPRING. THIS LARGE SCALE TRANSITION SUPPORTS GUIDANCE TEMPS OFFERING
HIGHS PUSHING 60 BY THURSDAY.

FIRST THING FIRST IS THE NEXT LOW PRESSURE SYSTEM MOVING THROUGH THE
CENTRAL ROCKIES TODAY ON SCHEDULE TO ARRIVE IN THE GREAT LAKES
SUNDAY. MODEL AGREEMENT REMAINS SOLID IN THE LATEST CYCLE WITH THE
DEPICTION OF MODEST SURFACE LEE CYCLOGENESIS OVER THE NORTHERN
PLAINS AND CANADIAN PRAIRIE...ENOUGH TO DRAW SOME GULF MODIFIED AIR
NORTHWARD TO AUGMENT MID LEVEL PACIFIC MOISTURE AND BRING
PRECIPITATION INTO SE MICHIGAN FROM MID SUNDAY AFTERNOON THROUGH
SUNDAY EVENING. THE DETERMINATION OF PRECIPITATION TYPE REMAINS
COMPLICATED BY STRONG WET BULB COOLING SHOWN IN MODEL SOUNDINGS
OPPOSED BY STRONG LOW LEVEL WARM ADVECTION. THE SAME MODEL SOUNDINGS
INDICATE THE BOUNDARY LAYER GROWING TO ABOUT 900 MB...GOOD ENOUGH
FOR SURFACE WIND GUSTS PUSHING 30 KNOTS...WHICH WILL EASILY CARRY
TEMPERATURES INTO THE LOWER 40S BEFORE THE MOISTURE ARRIVES. THE LOW
LEVEL JET CENTERED AROUND 850 MB WILL ALSO BE PUSHING 60 KNOTS WHICH
WILL BE CAPABLE OF DRIVING THE LOW LEVEL THERMAL RIDGE WELL INTO THE
SAGINAW VALLEY WITH THE ONSET OF PRECIPITATION. THE OVERALL STRENGTH
OF THE SOUTHWEST FLOW IS THEN EXPECTED TO SUPPORT AN ABOVE FREEZING
BOUNDARY LAYER TEMPERATURE PROFILE CLOSE TO 1500 FT DEEP INTO
SURFACE TEMPERATURES IN THE LOWER 40S...SUFFICIENT FOR MELTING TO
RAIN AS LONG AS PRECIPITATION RATE REMAINS AS LOW AS THAT IMPLIED BY
3 HR MODEL QPF AROUND 0.1 INCH.

A QUICK PASSAGE OF THE COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL
OCCUR SUNDAY NIGHT AND BRING A TRANSITION BACK TO SNOW SHOWERS
DURING THE EVENING. SOME LINGERING WRAP-AROUND MOISTURE WITH THE
UPPER WAVE WILL COMBINE WITH THE FRONTAL FORCING TO SUPPORT THE BEST
COVERAGE IN THE SAGINAW VALLEY AND THUMB RESULTING IN A SLUSHY
COATING BEFORE ENDING. COLD ADVECTION TRAILING THE FRONT DURING
MONDAY WILL NOT RESULT IN AS COLD AN AIR MASS AS WE ARE EXPERIENCING
THIS WEEKEND...BUT IT WILL BE ADEQUATE ENOUGH TO SET THE STAGE FOR
PRECIPITATION TYPE QUESTIONS AS THE NEXT SYSTEM ARRIVES MONDAY NIGHT
INTO TUESDAY. THIS ONE WILL BE MERELY A RIPPLE WITHIN THE BAROCLINIC
ZONE LEFT NEARBY TO THE SOUTH AND WEST AND APPEARS FRAUGHT WITH LOW
PREDICTABILITY. THE WAVE WILL BE OPEN ALOFT BUT THE MODELS OFFER A
BROAD RANGE OF SOLUTIONS ON THE DEPTH...TRACK...AND TIMING OF THE
SURFACE LOW/TROUGH. THE 00Z RUNS ARE TRENDING TOWARD A DEEPER
SURFACE WAVE MOVING THROUGH THE SOUTH HALF OF LOWER MICHIGAN LATE
MONDAY NIGHT THROUGH TUESDAY MORNING.

THE TUESDAY WAVE WILL BE THE LAST ONE BEFORE THE NORTHERN STREAM
BEGINS TO LIFT NORTHWARD WEDNESDAY INTO THURSDAY. THIS WILL BE DUE
TO THE LONG WAVE PATTERN SHIFT BEING DRIVEN BY A LARGER PACIFIC LOW
PRESSURE SYSTEM EXPECTED TO MOVE THROUGH CENTRAL CANADA THURSDAY.
GLOBAL MODEL SOLUTIONS INDICATE QUITE A BIT OF SPREAD IN THE UPPER
AIR PATTERN TOWARD THE END OF THE WEEK BUT THE DECREASED LONG WAVE
AMPLIFICATION WILL RESULT IN A MODERATING TEMPERATURE TREND IN
BETWEEN POTENTIAL ROUNDS OF SHOWERS INTO NEXT WEEKEND.

&&

.MARINE...

A BROAD AREA OF HIGH PRESSURE WILL SLIDE ACROSS THE GREAT LAKES
TODAY AND BRING FAVORABLE MARINE CONDITIONS THROUGH TONIGHT.
SOUTHWEST WIND WILL THEN INCREASE CONSIDERABLY DURING SUNDAY AS THE
NEXT LOW PRESSURE SYSTEM APPROACHES. GUSTS THROUGH SAGINAW BAY AND
OVER THE OPEN WATERS OF LAKE HURON WILL REACH 30 KNOTS BUT LIKELY
STAY BELOW GALES BEFORE MID LAKE. WARMER AIR MOVING OVER THE COLD
WATER AND REMAINING ICE WILL BE A LIMITING FACTOR DUE TO INCREASED
STABILITY. THE ASSOCIATED COLD FRONT WILL THEN SWEEP THROUGH SUNDAY
NIGHT BUT WILL NOT BRING AS MUCH COLD AIR AS WE HAVE SEEN RECENTLY.
NORTHWEST GUSTS NEAR 30 KNOTS WILL BE CONFINED TO THE NORTH HALF OF
LAKE HURON BEFORE HIGH PRESSURE BUILDS OVER THE REGION MONDAY.

&&

.AVIATION...ISSUED 1150 PM EDT FRI MAR 27 2015

IT APPEARS ONE LAST SURGE OF LOW LEVEL CLOUDS WILL PIVOT DOWN INTO
THE TERMINALS FROM LAKE HURON WITHIN NORTHEAST FLOW OF 5 TO 10
KNOTS. THIS WILL BRING A PERIOD OF LOWER VFR CIGS FROM KFNT ON
SOUTH. EXPECT CLEARING ON SATURDAY AS HIGH PRESSURE BUILDS INTO THE
AREA WITH WINDS BACKING TO NORTHWEST AND THEN BECOMING LIGHT AND
VARIABLE BY SATURDAY EVENING AS THE CENTER OF THIS HIGH REACHES THE
AREA.

FOR DTW...GENERALLY EXPECT FEW-SCT VFR CONDITIONS...BUT THERE WILL
BE A CHANCE OF A SEVERAL HOUR PERIOD OF BKN CIGS AROUND 5KFT LATE
TONIGHT AS MOISTURE FUNNELS INTO AREA FROM THE THUMB.

//DTW THRESHOLD PROBABILITIES...

* LOW CONFIDENCE IN CEILINGS AROUND 5000 FT THROUGH LATE TONIGHT
  INTO EARLY SATURDAY MORNING.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

SHORT TERM...CB
LONG TERM....BT
MARINE.......BT
AVIATION.....DG


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




000
FXUS63 KDTX 280757
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
357 AM EDT SAT MAR 28 2015

.SHORT TERM...TODAY AND TONIGHT

A COUPLE OF FACTORS HAVE COMBINED TO HELP THE SHORE PARALLEL BAND OF
LIGHT LAKE EFFECT SNOW TO PERSIST ALONG THE SHORELINE OF LAKE HURON
OVERNIGHT. THE FIRST HAS BEEN THE STREAMLINING OF NORTHERLY SURFACE
WIND TRAJECTORIES TO PRODUCE AN AREA OF LOCALIZED CONVERGENCE.
SURFACE OBSERVATIONS HAVE BEEN REPORTING A WESTERLY TRAJECTORY OVER
THE EASTERN HALF OF THE LOWER PENINSULA AND EASTERLY TRAJECTORIES AT
THE SHORELINE...PORT HOPE/SARNIA. STATIC NATURE OF THE BANDING
ON RADAR IN ADDITION TO NEGATIVE LOW LEVEL THETA E LAPSE RATES
AND NEAR SURFACE CONVERGENCE CONTINUING IN MODEL DATA THROUGH 9Z
SUGGESTS THE SNOW SHOWER POTENTIAL HAS ANOTHER 2 TO 4 HOURS. RAP
OUTPUT SUGGESTS THERE IS SOME ORGANIZED SIGNAL TO DEEPER MIDLEVEL
MOISTURE ROTATING CYCLONICALLY AROUND A CENTER POINT OVER THE
EASTERN END OF LAKE ERIE. THIS SUGGESTS THE
DEEPER MOISTURE WILL PIVOT AWAY FROM THE LOW LEVEL INSTABILITY
SOURCE IN THE NEXT FEW HOURS. THOUGHT IS AS THIS MOISTURE PUSHES
SOUTHWARD AWAY FROM SOUTHERN LAKE HURON WILL SEE LAKE EFFECT
ACTIVITY WANE AFTER 9Z. REGARDLESS...SNOW SHOWERS REMAIN LIKELY IN
THE NEAR TERM WITH MINOR ACCUMULATIONS POSSIBLE ALONG THE SHORELINE.

DIFFERENTIAL GEOPOTENTIAL HEIGHT REBOUND WILL CAUSE SURFACE HIGH
PRESSURE TO EXPAND AGGRESIVELY EASTWARD THROUGH THE CWA BY MIDDAY.
LOW TO MIDLEVEL FLOW TRAJECTORIES DEPICT STUBBORN CYCLONIC FLOW INTO
THE LATE AFTERNOON BEFORE EVENTUALLY RELINQUISHING BY LATE
AFTERNOON. THE ARRIVAL OF THE ANTICYCLONIC FLOW WILL PROBABLY END
ANY POTENTIAL FOR CONTINUED LAKE EFFECT CLOUD THAT MAY HANG ON
ACROSS THE EASTERN CWA TODAY. WITH NORTHERLY FLOW FIRMLY IN
CONTROL...WANTED TO HANG CLOSE TO GUIDANCE WITH TEMPERATURES AROUND
30 TO THE LOW 30S POSSIBLE.

QUIET WEATHER IS FORECASTED TONIGHT WITH HIGH PRESSURE AT THE
SURFACE AND SHORTWAVE RIDGING ALOFT. TEMEPRATURES WILL AGAIN BE COLD
WITH READINGS FALLING INTO THE TEENS ACROSS ALL OF THE AREA (10 TO
15 DEGREES BELOW AVERAGES).

&&

.LONG TERM...

SUNDAY WILL START AN ACTIVE PERIOD OF WEATHER CONSISTING OF A SERIES
OF SHORT WAVES MOVING THROUGH THE NORTHERN TIER OF STATES THROUGH
NEXT WEEK. WHILE IT WILL BE ACTIVE IN TERMS OF PRECIPITATION...THERE
WILL BE AN UNDERLYING WARMING TREND THROUGH THE PERIOD. THIS WILL BE
DRIVEN BY AN ENERGETIC PACIFIC UPPER LEVEL JET THAT WILL FORCE A
TRANSITION OUT OF THE LONG WAVE RIDGE OVER THE WEST/TROUGH OVER THE
EAST THAT HAS BEEN SO PERSISTENT AND RESISTANT TO THE ONSET OF
SPRING. THIS LARGE SCALE TRANSITION SUPPORTS GUIDANCE TEMPS OFFERING
HIGHS PUSHING 60 BY THURSDAY.

FIRST THING FIRST IS THE NEXT LOW PRESSURE SYSTEM MOVING THROUGH THE
CENTRAL ROCKIES TODAY ON SCHEDULE TO ARRIVE IN THE GREAT LAKES
SUNDAY. MODEL AGREEMENT REMAINS SOLID IN THE LATEST CYCLE WITH THE
DEPICTION OF MODEST SURFACE LEE CYCLOGENESIS OVER THE NORTHERN
PLAINS AND CANADIAN PRAIRIE...ENOUGH TO DRAW SOME GULF MODIFIED AIR
NORTHWARD TO AUGMENT MID LEVEL PACIFIC MOISTURE AND BRING
PRECIPITATION INTO SE MICHIGAN FROM MID SUNDAY AFTERNOON THROUGH
SUNDAY EVENING. THE DETERMINATION OF PRECIPITATION TYPE REMAINS
COMPLICATED BY STRONG WET BULB COOLING SHOWN IN MODEL SOUNDINGS
OPPOSED BY STRONG LOW LEVEL WARM ADVECTION. THE SAME MODEL SOUNDINGS
INDICATE THE BOUNDARY LAYER GROWING TO ABOUT 900 MB...GOOD ENOUGH
FOR SURFACE WIND GUSTS PUSHING 30 KNOTS...WHICH WILL EASILY CARRY
TEMPERATURES INTO THE LOWER 40S BEFORE THE MOISTURE ARRIVES. THE LOW
LEVEL JET CENTERED AROUND 850 MB WILL ALSO BE PUSHING 60 KNOTS WHICH
WILL BE CAPABLE OF DRIVING THE LOW LEVEL THERMAL RIDGE WELL INTO THE
SAGINAW VALLEY WITH THE ONSET OF PRECIPITATION. THE OVERALL STRENGTH
OF THE SOUTHWEST FLOW IS THEN EXPECTED TO SUPPORT AN ABOVE FREEZING
BOUNDARY LAYER TEMPERATURE PROFILE CLOSE TO 1500 FT DEEP INTO
SURFACE TEMPERATURES IN THE LOWER 40S...SUFFICIENT FOR MELTING TO
RAIN AS LONG AS PRECIPITATION RATE REMAINS AS LOW AS THAT IMPLIED BY
3 HR MODEL QPF AROUND 0.1 INCH.

A QUICK PASSAGE OF THE COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL
OCCUR SUNDAY NIGHT AND BRING A TRANSITION BACK TO SNOW SHOWERS
DURING THE EVENING. SOME LINGERING WRAP-AROUND MOISTURE WITH THE
UPPER WAVE WILL COMBINE WITH THE FRONTAL FORCING TO SUPPORT THE BEST
COVERAGE IN THE SAGINAW VALLEY AND THUMB RESULTING IN A SLUSHY
COATING BEFORE ENDING. COLD ADVECTION TRAILING THE FRONT DURING
MONDAY WILL NOT RESULT IN AS COLD AN AIR MASS AS WE ARE EXPERIENCING
THIS WEEKEND...BUT IT WILL BE ADEQUATE ENOUGH TO SET THE STAGE FOR
PRECIPITATION TYPE QUESTIONS AS THE NEXT SYSTEM ARRIVES MONDAY NIGHT
INTO TUESDAY. THIS ONE WILL BE MERELY A RIPPLE WITHIN THE BAROCLINIC
ZONE LEFT NEARBY TO THE SOUTH AND WEST AND APPEARS FRAUGHT WITH LOW
PREDICTABILITY. THE WAVE WILL BE OPEN ALOFT BUT THE MODELS OFFER A
BROAD RANGE OF SOLUTIONS ON THE DEPTH...TRACK...AND TIMING OF THE
SURFACE LOW/TROUGH. THE 00Z RUNS ARE TRENDING TOWARD A DEEPER
SURFACE WAVE MOVING THROUGH THE SOUTH HALF OF LOWER MICHIGAN LATE
MONDAY NIGHT THROUGH TUESDAY MORNING.

THE TUESDAY WAVE WILL BE THE LAST ONE BEFORE THE NORTHERN STREAM
BEGINS TO LIFT NORTHWARD WEDNESDAY INTO THURSDAY. THIS WILL BE DUE
TO THE LONG WAVE PATTERN SHIFT BEING DRIVEN BY A LARGER PACIFIC LOW
PRESSURE SYSTEM EXPECTED TO MOVE THROUGH CENTRAL CANADA THURSDAY.
GLOBAL MODEL SOLUTIONS INDICATE QUITE A BIT OF SPREAD IN THE UPPER
AIR PATTERN TOWARD THE END OF THE WEEK BUT THE DECREASED LONG WAVE
AMPLIFICATION WILL RESULT IN A MODERATING TEMPERATURE TREND IN
BETWEEN POTENTIAL ROUNDS OF SHOWERS INTO NEXT WEEKEND.

&&

.MARINE...

A BROAD AREA OF HIGH PRESSURE WILL SLIDE ACROSS THE GREAT LAKES
TODAY AND BRING FAVORABLE MARINE CONDITIONS THROUGH TONIGHT.
SOUTHWEST WIND WILL THEN INCREASE CONSIDERABLY DURING SUNDAY AS THE
NEXT LOW PRESSURE SYSTEM APPROACHES. GUSTS THROUGH SAGINAW BAY AND
OVER THE OPEN WATERS OF LAKE HURON WILL REACH 30 KNOTS BUT LIKELY
STAY BELOW GALES BEFORE MID LAKE. WARMER AIR MOVING OVER THE COLD
WATER AND REMAINING ICE WILL BE A LIMITING FACTOR DUE TO INCREASED
STABILITY. THE ASSOCIATED COLD FRONT WILL THEN SWEEP THROUGH SUNDAY
NIGHT BUT WILL NOT BRING AS MUCH COLD AIR AS WE HAVE SEEN RECENTLY.
NORTHWEST GUSTS NEAR 30 KNOTS WILL BE CONFINED TO THE NORTH HALF OF
LAKE HURON BEFORE HIGH PRESSURE BUILDS OVER THE REGION MONDAY.

&&

.AVIATION...ISSUED 1150 PM EDT FRI MAR 27 2015

IT APPEARS ONE LAST SURGE OF LOW LEVEL CLOUDS WILL PIVOT DOWN INTO
THE TERMINALS FROM LAKE HURON WITHIN NORTHEAST FLOW OF 5 TO 10
KNOTS. THIS WILL BRING A PERIOD OF LOWER VFR CIGS FROM KFNT ON
SOUTH. EXPECT CLEARING ON SATURDAY AS HIGH PRESSURE BUILDS INTO THE
AREA WITH WINDS BACKING TO NORTHWEST AND THEN BECOMING LIGHT AND
VARIABLE BY SATURDAY EVENING AS THE CENTER OF THIS HIGH REACHES THE
AREA.

FOR DTW...GENERALLY EXPECT FEW-SCT VFR CONDITIONS...BUT THERE WILL
BE A CHANCE OF A SEVERAL HOUR PERIOD OF BKN CIGS AROUND 5KFT LATE
TONIGHT AS MOISTURE FUNNELS INTO AREA FROM THE THUMB.

//DTW THRESHOLD PROBABILITIES...

* LOW CONFIDENCE IN CEILINGS AROUND 5000 FT THROUGH LATE TONIGHT
  INTO EARLY SATURDAY MORNING.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

SHORT TERM...CB
LONG TERM....BT
MARINE.......BT
AVIATION.....DG


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





000
FXUS63 KDTX 280757
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
357 AM EDT SAT MAR 28 2015

.SHORT TERM...TODAY AND TONIGHT

A COUPLE OF FACTORS HAVE COMBINED TO HELP THE SHORE PARALLEL BAND OF
LIGHT LAKE EFFECT SNOW TO PERSIST ALONG THE SHORELINE OF LAKE HURON
OVERNIGHT. THE FIRST HAS BEEN THE STREAMLINING OF NORTHERLY SURFACE
WIND TRAJECTORIES TO PRODUCE AN AREA OF LOCALIZED CONVERGENCE.
SURFACE OBSERVATIONS HAVE BEEN REPORTING A WESTERLY TRAJECTORY OVER
THE EASTERN HALF OF THE LOWER PENINSULA AND EASTERLY TRAJECTORIES AT
THE SHORELINE...PORT HOPE/SARNIA. STATIC NATURE OF THE BANDING
ON RADAR IN ADDITION TO NEGATIVE LOW LEVEL THETA E LAPSE RATES
AND NEAR SURFACE CONVERGENCE CONTINUING IN MODEL DATA THROUGH 9Z
SUGGESTS THE SNOW SHOWER POTENTIAL HAS ANOTHER 2 TO 4 HOURS. RAP
OUTPUT SUGGESTS THERE IS SOME ORGANIZED SIGNAL TO DEEPER MIDLEVEL
MOISTURE ROTATING CYCLONICALLY AROUND A CENTER POINT OVER THE
EASTERN END OF LAKE ERIE. THIS SUGGESTS THE
DEEPER MOISTURE WILL PIVOT AWAY FROM THE LOW LEVEL INSTABILITY
SOURCE IN THE NEXT FEW HOURS. THOUGHT IS AS THIS MOISTURE PUSHES
SOUTHWARD AWAY FROM SOUTHERN LAKE HURON WILL SEE LAKE EFFECT
ACTIVITY WANE AFTER 9Z. REGARDLESS...SNOW SHOWERS REMAIN LIKELY IN
THE NEAR TERM WITH MINOR ACCUMULATIONS POSSIBLE ALONG THE SHORELINE.

DIFFERENTIAL GEOPOTENTIAL HEIGHT REBOUND WILL CAUSE SURFACE HIGH
PRESSURE TO EXPAND AGGRESIVELY EASTWARD THROUGH THE CWA BY MIDDAY.
LOW TO MIDLEVEL FLOW TRAJECTORIES DEPICT STUBBORN CYCLONIC FLOW INTO
THE LATE AFTERNOON BEFORE EVENTUALLY RELINQUISHING BY LATE
AFTERNOON. THE ARRIVAL OF THE ANTICYCLONIC FLOW WILL PROBABLY END
ANY POTENTIAL FOR CONTINUED LAKE EFFECT CLOUD THAT MAY HANG ON
ACROSS THE EASTERN CWA TODAY. WITH NORTHERLY FLOW FIRMLY IN
CONTROL...WANTED TO HANG CLOSE TO GUIDANCE WITH TEMPERATURES AROUND
30 TO THE LOW 30S POSSIBLE.

QUIET WEATHER IS FORECASTED TONIGHT WITH HIGH PRESSURE AT THE
SURFACE AND SHORTWAVE RIDGING ALOFT. TEMEPRATURES WILL AGAIN BE COLD
WITH READINGS FALLING INTO THE TEENS ACROSS ALL OF THE AREA (10 TO
15 DEGREES BELOW AVERAGES).

&&

.LONG TERM...

SUNDAY WILL START AN ACTIVE PERIOD OF WEATHER CONSISTING OF A SERIES
OF SHORT WAVES MOVING THROUGH THE NORTHERN TIER OF STATES THROUGH
NEXT WEEK. WHILE IT WILL BE ACTIVE IN TERMS OF PRECIPITATION...THERE
WILL BE AN UNDERLYING WARMING TREND THROUGH THE PERIOD. THIS WILL BE
DRIVEN BY AN ENERGETIC PACIFIC UPPER LEVEL JET THAT WILL FORCE A
TRANSITION OUT OF THE LONG WAVE RIDGE OVER THE WEST/TROUGH OVER THE
EAST THAT HAS BEEN SO PERSISTENT AND RESISTANT TO THE ONSET OF
SPRING. THIS LARGE SCALE TRANSITION SUPPORTS GUIDANCE TEMPS OFFERING
HIGHS PUSHING 60 BY THURSDAY.

FIRST THING FIRST IS THE NEXT LOW PRESSURE SYSTEM MOVING THROUGH THE
CENTRAL ROCKIES TODAY ON SCHEDULE TO ARRIVE IN THE GREAT LAKES
SUNDAY. MODEL AGREEMENT REMAINS SOLID IN THE LATEST CYCLE WITH THE
DEPICTION OF MODEST SURFACE LEE CYCLOGENESIS OVER THE NORTHERN
PLAINS AND CANADIAN PRAIRIE...ENOUGH TO DRAW SOME GULF MODIFIED AIR
NORTHWARD TO AUGMENT MID LEVEL PACIFIC MOISTURE AND BRING
PRECIPITATION INTO SE MICHIGAN FROM MID SUNDAY AFTERNOON THROUGH
SUNDAY EVENING. THE DETERMINATION OF PRECIPITATION TYPE REMAINS
COMPLICATED BY STRONG WET BULB COOLING SHOWN IN MODEL SOUNDINGS
OPPOSED BY STRONG LOW LEVEL WARM ADVECTION. THE SAME MODEL SOUNDINGS
INDICATE THE BOUNDARY LAYER GROWING TO ABOUT 900 MB...GOOD ENOUGH
FOR SURFACE WIND GUSTS PUSHING 30 KNOTS...WHICH WILL EASILY CARRY
TEMPERATURES INTO THE LOWER 40S BEFORE THE MOISTURE ARRIVES. THE LOW
LEVEL JET CENTERED AROUND 850 MB WILL ALSO BE PUSHING 60 KNOTS WHICH
WILL BE CAPABLE OF DRIVING THE LOW LEVEL THERMAL RIDGE WELL INTO THE
SAGINAW VALLEY WITH THE ONSET OF PRECIPITATION. THE OVERALL STRENGTH
OF THE SOUTHWEST FLOW IS THEN EXPECTED TO SUPPORT AN ABOVE FREEZING
BOUNDARY LAYER TEMPERATURE PROFILE CLOSE TO 1500 FT DEEP INTO
SURFACE TEMPERATURES IN THE LOWER 40S...SUFFICIENT FOR MELTING TO
RAIN AS LONG AS PRECIPITATION RATE REMAINS AS LOW AS THAT IMPLIED BY
3 HR MODEL QPF AROUND 0.1 INCH.

A QUICK PASSAGE OF THE COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL
OCCUR SUNDAY NIGHT AND BRING A TRANSITION BACK TO SNOW SHOWERS
DURING THE EVENING. SOME LINGERING WRAP-AROUND MOISTURE WITH THE
UPPER WAVE WILL COMBINE WITH THE FRONTAL FORCING TO SUPPORT THE BEST
COVERAGE IN THE SAGINAW VALLEY AND THUMB RESULTING IN A SLUSHY
COATING BEFORE ENDING. COLD ADVECTION TRAILING THE FRONT DURING
MONDAY WILL NOT RESULT IN AS COLD AN AIR MASS AS WE ARE EXPERIENCING
THIS WEEKEND...BUT IT WILL BE ADEQUATE ENOUGH TO SET THE STAGE FOR
PRECIPITATION TYPE QUESTIONS AS THE NEXT SYSTEM ARRIVES MONDAY NIGHT
INTO TUESDAY. THIS ONE WILL BE MERELY A RIPPLE WITHIN THE BAROCLINIC
ZONE LEFT NEARBY TO THE SOUTH AND WEST AND APPEARS FRAUGHT WITH LOW
PREDICTABILITY. THE WAVE WILL BE OPEN ALOFT BUT THE MODELS OFFER A
BROAD RANGE OF SOLUTIONS ON THE DEPTH...TRACK...AND TIMING OF THE
SURFACE LOW/TROUGH. THE 00Z RUNS ARE TRENDING TOWARD A DEEPER
SURFACE WAVE MOVING THROUGH THE SOUTH HALF OF LOWER MICHIGAN LATE
MONDAY NIGHT THROUGH TUESDAY MORNING.

THE TUESDAY WAVE WILL BE THE LAST ONE BEFORE THE NORTHERN STREAM
BEGINS TO LIFT NORTHWARD WEDNESDAY INTO THURSDAY. THIS WILL BE DUE
TO THE LONG WAVE PATTERN SHIFT BEING DRIVEN BY A LARGER PACIFIC LOW
PRESSURE SYSTEM EXPECTED TO MOVE THROUGH CENTRAL CANADA THURSDAY.
GLOBAL MODEL SOLUTIONS INDICATE QUITE A BIT OF SPREAD IN THE UPPER
AIR PATTERN TOWARD THE END OF THE WEEK BUT THE DECREASED LONG WAVE
AMPLIFICATION WILL RESULT IN A MODERATING TEMPERATURE TREND IN
BETWEEN POTENTIAL ROUNDS OF SHOWERS INTO NEXT WEEKEND.

&&

.MARINE...

A BROAD AREA OF HIGH PRESSURE WILL SLIDE ACROSS THE GREAT LAKES
TODAY AND BRING FAVORABLE MARINE CONDITIONS THROUGH TONIGHT.
SOUTHWEST WIND WILL THEN INCREASE CONSIDERABLY DURING SUNDAY AS THE
NEXT LOW PRESSURE SYSTEM APPROACHES. GUSTS THROUGH SAGINAW BAY AND
OVER THE OPEN WATERS OF LAKE HURON WILL REACH 30 KNOTS BUT LIKELY
STAY BELOW GALES BEFORE MID LAKE. WARMER AIR MOVING OVER THE COLD
WATER AND REMAINING ICE WILL BE A LIMITING FACTOR DUE TO INCREASED
STABILITY. THE ASSOCIATED COLD FRONT WILL THEN SWEEP THROUGH SUNDAY
NIGHT BUT WILL NOT BRING AS MUCH COLD AIR AS WE HAVE SEEN RECENTLY.
NORTHWEST GUSTS NEAR 30 KNOTS WILL BE CONFINED TO THE NORTH HALF OF
LAKE HURON BEFORE HIGH PRESSURE BUILDS OVER THE REGION MONDAY.

&&

.AVIATION...ISSUED 1150 PM EDT FRI MAR 27 2015

IT APPEARS ONE LAST SURGE OF LOW LEVEL CLOUDS WILL PIVOT DOWN INTO
THE TERMINALS FROM LAKE HURON WITHIN NORTHEAST FLOW OF 5 TO 10
KNOTS. THIS WILL BRING A PERIOD OF LOWER VFR CIGS FROM KFNT ON
SOUTH. EXPECT CLEARING ON SATURDAY AS HIGH PRESSURE BUILDS INTO THE
AREA WITH WINDS BACKING TO NORTHWEST AND THEN BECOMING LIGHT AND
VARIABLE BY SATURDAY EVENING AS THE CENTER OF THIS HIGH REACHES THE
AREA.

FOR DTW...GENERALLY EXPECT FEW-SCT VFR CONDITIONS...BUT THERE WILL
BE A CHANCE OF A SEVERAL HOUR PERIOD OF BKN CIGS AROUND 5KFT LATE
TONIGHT AS MOISTURE FUNNELS INTO AREA FROM THE THUMB.

//DTW THRESHOLD PROBABILITIES...

* LOW CONFIDENCE IN CEILINGS AROUND 5000 FT THROUGH LATE TONIGHT
  INTO EARLY SATURDAY MORNING.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

SHORT TERM...CB
LONG TERM....BT
MARINE.......BT
AVIATION.....DG


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




000
FXUS63 KDTX 280757
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
357 AM EDT SAT MAR 28 2015

.SHORT TERM...TODAY AND TONIGHT

A COUPLE OF FACTORS HAVE COMBINED TO HELP THE SHORE PARALLEL BAND OF
LIGHT LAKE EFFECT SNOW TO PERSIST ALONG THE SHORELINE OF LAKE HURON
OVERNIGHT. THE FIRST HAS BEEN THE STREAMLINING OF NORTHERLY SURFACE
WIND TRAJECTORIES TO PRODUCE AN AREA OF LOCALIZED CONVERGENCE.
SURFACE OBSERVATIONS HAVE BEEN REPORTING A WESTERLY TRAJECTORY OVER
THE EASTERN HALF OF THE LOWER PENINSULA AND EASTERLY TRAJECTORIES AT
THE SHORELINE...PORT HOPE/SARNIA. STATIC NATURE OF THE BANDING
ON RADAR IN ADDITION TO NEGATIVE LOW LEVEL THETA E LAPSE RATES
AND NEAR SURFACE CONVERGENCE CONTINUING IN MODEL DATA THROUGH 9Z
SUGGESTS THE SNOW SHOWER POTENTIAL HAS ANOTHER 2 TO 4 HOURS. RAP
OUTPUT SUGGESTS THERE IS SOME ORGANIZED SIGNAL TO DEEPER MIDLEVEL
MOISTURE ROTATING CYCLONICALLY AROUND A CENTER POINT OVER THE
EASTERN END OF LAKE ERIE. THIS SUGGESTS THE
DEEPER MOISTURE WILL PIVOT AWAY FROM THE LOW LEVEL INSTABILITY
SOURCE IN THE NEXT FEW HOURS. THOUGHT IS AS THIS MOISTURE PUSHES
SOUTHWARD AWAY FROM SOUTHERN LAKE HURON WILL SEE LAKE EFFECT
ACTIVITY WANE AFTER 9Z. REGARDLESS...SNOW SHOWERS REMAIN LIKELY IN
THE NEAR TERM WITH MINOR ACCUMULATIONS POSSIBLE ALONG THE SHORELINE.

DIFFERENTIAL GEOPOTENTIAL HEIGHT REBOUND WILL CAUSE SURFACE HIGH
PRESSURE TO EXPAND AGGRESIVELY EASTWARD THROUGH THE CWA BY MIDDAY.
LOW TO MIDLEVEL FLOW TRAJECTORIES DEPICT STUBBORN CYCLONIC FLOW INTO
THE LATE AFTERNOON BEFORE EVENTUALLY RELINQUISHING BY LATE
AFTERNOON. THE ARRIVAL OF THE ANTICYCLONIC FLOW WILL PROBABLY END
ANY POTENTIAL FOR CONTINUED LAKE EFFECT CLOUD THAT MAY HANG ON
ACROSS THE EASTERN CWA TODAY. WITH NORTHERLY FLOW FIRMLY IN
CONTROL...WANTED TO HANG CLOSE TO GUIDANCE WITH TEMPERATURES AROUND
30 TO THE LOW 30S POSSIBLE.

QUIET WEATHER IS FORECASTED TONIGHT WITH HIGH PRESSURE AT THE
SURFACE AND SHORTWAVE RIDGING ALOFT. TEMEPRATURES WILL AGAIN BE COLD
WITH READINGS FALLING INTO THE TEENS ACROSS ALL OF THE AREA (10 TO
15 DEGREES BELOW AVERAGES).

&&

.LONG TERM...

SUNDAY WILL START AN ACTIVE PERIOD OF WEATHER CONSISTING OF A SERIES
OF SHORT WAVES MOVING THROUGH THE NORTHERN TIER OF STATES THROUGH
NEXT WEEK. WHILE IT WILL BE ACTIVE IN TERMS OF PRECIPITATION...THERE
WILL BE AN UNDERLYING WARMING TREND THROUGH THE PERIOD. THIS WILL BE
DRIVEN BY AN ENERGETIC PACIFIC UPPER LEVEL JET THAT WILL FORCE A
TRANSITION OUT OF THE LONG WAVE RIDGE OVER THE WEST/TROUGH OVER THE
EAST THAT HAS BEEN SO PERSISTENT AND RESISTANT TO THE ONSET OF
SPRING. THIS LARGE SCALE TRANSITION SUPPORTS GUIDANCE TEMPS OFFERING
HIGHS PUSHING 60 BY THURSDAY.

FIRST THING FIRST IS THE NEXT LOW PRESSURE SYSTEM MOVING THROUGH THE
CENTRAL ROCKIES TODAY ON SCHEDULE TO ARRIVE IN THE GREAT LAKES
SUNDAY. MODEL AGREEMENT REMAINS SOLID IN THE LATEST CYCLE WITH THE
DEPICTION OF MODEST SURFACE LEE CYCLOGENESIS OVER THE NORTHERN
PLAINS AND CANADIAN PRAIRIE...ENOUGH TO DRAW SOME GULF MODIFIED AIR
NORTHWARD TO AUGMENT MID LEVEL PACIFIC MOISTURE AND BRING
PRECIPITATION INTO SE MICHIGAN FROM MID SUNDAY AFTERNOON THROUGH
SUNDAY EVENING. THE DETERMINATION OF PRECIPITATION TYPE REMAINS
COMPLICATED BY STRONG WET BULB COOLING SHOWN IN MODEL SOUNDINGS
OPPOSED BY STRONG LOW LEVEL WARM ADVECTION. THE SAME MODEL SOUNDINGS
INDICATE THE BOUNDARY LAYER GROWING TO ABOUT 900 MB...GOOD ENOUGH
FOR SURFACE WIND GUSTS PUSHING 30 KNOTS...WHICH WILL EASILY CARRY
TEMPERATURES INTO THE LOWER 40S BEFORE THE MOISTURE ARRIVES. THE LOW
LEVEL JET CENTERED AROUND 850 MB WILL ALSO BE PUSHING 60 KNOTS WHICH
WILL BE CAPABLE OF DRIVING THE LOW LEVEL THERMAL RIDGE WELL INTO THE
SAGINAW VALLEY WITH THE ONSET OF PRECIPITATION. THE OVERALL STRENGTH
OF THE SOUTHWEST FLOW IS THEN EXPECTED TO SUPPORT AN ABOVE FREEZING
BOUNDARY LAYER TEMPERATURE PROFILE CLOSE TO 1500 FT DEEP INTO
SURFACE TEMPERATURES IN THE LOWER 40S...SUFFICIENT FOR MELTING TO
RAIN AS LONG AS PRECIPITATION RATE REMAINS AS LOW AS THAT IMPLIED BY
3 HR MODEL QPF AROUND 0.1 INCH.

A QUICK PASSAGE OF THE COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL
OCCUR SUNDAY NIGHT AND BRING A TRANSITION BACK TO SNOW SHOWERS
DURING THE EVENING. SOME LINGERING WRAP-AROUND MOISTURE WITH THE
UPPER WAVE WILL COMBINE WITH THE FRONTAL FORCING TO SUPPORT THE BEST
COVERAGE IN THE SAGINAW VALLEY AND THUMB RESULTING IN A SLUSHY
COATING BEFORE ENDING. COLD ADVECTION TRAILING THE FRONT DURING
MONDAY WILL NOT RESULT IN AS COLD AN AIR MASS AS WE ARE EXPERIENCING
THIS WEEKEND...BUT IT WILL BE ADEQUATE ENOUGH TO SET THE STAGE FOR
PRECIPITATION TYPE QUESTIONS AS THE NEXT SYSTEM ARRIVES MONDAY NIGHT
INTO TUESDAY. THIS ONE WILL BE MERELY A RIPPLE WITHIN THE BAROCLINIC
ZONE LEFT NEARBY TO THE SOUTH AND WEST AND APPEARS FRAUGHT WITH LOW
PREDICTABILITY. THE WAVE WILL BE OPEN ALOFT BUT THE MODELS OFFER A
BROAD RANGE OF SOLUTIONS ON THE DEPTH...TRACK...AND TIMING OF THE
SURFACE LOW/TROUGH. THE 00Z RUNS ARE TRENDING TOWARD A DEEPER
SURFACE WAVE MOVING THROUGH THE SOUTH HALF OF LOWER MICHIGAN LATE
MONDAY NIGHT THROUGH TUESDAY MORNING.

THE TUESDAY WAVE WILL BE THE LAST ONE BEFORE THE NORTHERN STREAM
BEGINS TO LIFT NORTHWARD WEDNESDAY INTO THURSDAY. THIS WILL BE DUE
TO THE LONG WAVE PATTERN SHIFT BEING DRIVEN BY A LARGER PACIFIC LOW
PRESSURE SYSTEM EXPECTED TO MOVE THROUGH CENTRAL CANADA THURSDAY.
GLOBAL MODEL SOLUTIONS INDICATE QUITE A BIT OF SPREAD IN THE UPPER
AIR PATTERN TOWARD THE END OF THE WEEK BUT THE DECREASED LONG WAVE
AMPLIFICATION WILL RESULT IN A MODERATING TEMPERATURE TREND IN
BETWEEN POTENTIAL ROUNDS OF SHOWERS INTO NEXT WEEKEND.

&&

.MARINE...

A BROAD AREA OF HIGH PRESSURE WILL SLIDE ACROSS THE GREAT LAKES
TODAY AND BRING FAVORABLE MARINE CONDITIONS THROUGH TONIGHT.
SOUTHWEST WIND WILL THEN INCREASE CONSIDERABLY DURING SUNDAY AS THE
NEXT LOW PRESSURE SYSTEM APPROACHES. GUSTS THROUGH SAGINAW BAY AND
OVER THE OPEN WATERS OF LAKE HURON WILL REACH 30 KNOTS BUT LIKELY
STAY BELOW GALES BEFORE MID LAKE. WARMER AIR MOVING OVER THE COLD
WATER AND REMAINING ICE WILL BE A LIMITING FACTOR DUE TO INCREASED
STABILITY. THE ASSOCIATED COLD FRONT WILL THEN SWEEP THROUGH SUNDAY
NIGHT BUT WILL NOT BRING AS MUCH COLD AIR AS WE HAVE SEEN RECENTLY.
NORTHWEST GUSTS NEAR 30 KNOTS WILL BE CONFINED TO THE NORTH HALF OF
LAKE HURON BEFORE HIGH PRESSURE BUILDS OVER THE REGION MONDAY.

&&

.AVIATION...ISSUED 1150 PM EDT FRI MAR 27 2015

IT APPEARS ONE LAST SURGE OF LOW LEVEL CLOUDS WILL PIVOT DOWN INTO
THE TERMINALS FROM LAKE HURON WITHIN NORTHEAST FLOW OF 5 TO 10
KNOTS. THIS WILL BRING A PERIOD OF LOWER VFR CIGS FROM KFNT ON
SOUTH. EXPECT CLEARING ON SATURDAY AS HIGH PRESSURE BUILDS INTO THE
AREA WITH WINDS BACKING TO NORTHWEST AND THEN BECOMING LIGHT AND
VARIABLE BY SATURDAY EVENING AS THE CENTER OF THIS HIGH REACHES THE
AREA.

FOR DTW...GENERALLY EXPECT FEW-SCT VFR CONDITIONS...BUT THERE WILL
BE A CHANCE OF A SEVERAL HOUR PERIOD OF BKN CIGS AROUND 5KFT LATE
TONIGHT AS MOISTURE FUNNELS INTO AREA FROM THE THUMB.

//DTW THRESHOLD PROBABILITIES...

* LOW CONFIDENCE IN CEILINGS AROUND 5000 FT THROUGH LATE TONIGHT
  INTO EARLY SATURDAY MORNING.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

SHORT TERM...CB
LONG TERM....BT
MARINE.......BT
AVIATION.....DG


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





000
FXUS63 KDTX 280350
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1150 PM EDT FRI MAR 27 2015


.AVIATION...

IT APPEARS ONE LAST SURGE OF LOW LEVEL CLOUDS WILL PIVOT DOWN INTO
THE TERMINALS FROM LAKE HURON WITHIN NORTHEAST FLOW OF 5 TO 10
KNOTS. THIS WILL BRING A PERIOD OF LOWER VFR CIGS FROM KFNT ON
SOUTH. EXPECT CLEARING ON SATURDAY AS HIGH PRESSURE BUILDS INTO THE
AREA WITH WINDS BACKING TO NORTHWEST AND THEN BECOMING LIGHT AND
VARIABLE BY SATURDAY EVENING AS THE CENTER OF THIS HIGH REACHES THE
AREA.

FOR DTW...GENERALLY EXPECT FEW-SCT VFR CONDITIONS...BUT THERE WILL
BE A CHANCE OF A SEVERAL HOUR PERIOD OF BKN CIGS AROUND 5KFT LATE
TONIGHT AS MOISTURE FUNNELS INTO AREA FROM THE THUMB.


//DTW THRESHOLD PROBABILITIES...

* LOW CONFIDENCE IN CEILINGS AROUND 5000 FT THROUGH LATE TONIGHT
  INTO EARLY SATURDAY MORNING.

&&

.PREV DISCUSSION...ISSUED 340 PM EDT FRI MAR 27 2015

SHORT TERM...TONIGHT

GOOD SUBSIDENCE AND DRYING OCCURRING BEHIND UPPER LEVEL TROUGH AXIS
MOVING THROUGH THE CENTRAL GREAT LAKES THIS AFTERNOON...WITH SURFACE
DEW PTS PLUNGING TO AROUND ZERO OVER CENTRAL SECTIONS OF THE
STATE...UNDER MOSTLY CLEAR SKIES. CLOUDS HAVE THINNED OUT OVER
SOUTHEAST MICHIGAN...BUT COLD (NEGATIVE UPPER TEENS AT 850 MB)
NORTHERLY FLOW OFF LAKE HURON IS MAINTAINING JUST ENOUGH MOISTURE TO
MAINTAIN MOSTLY CLOUDY SKIES AND EMBEDDED SNOW SHOWERS. THE ACTIVITY
IS VERY DISORGANIZED...BUT STEEP LOW LEVEL LAPSE RATES HAVE PRODUCED
VERY SMALL INTENSE CELLS...DROPPING VSYBS BRIEFLY BELOW 1 MILE IN
ISOLATED SPOTS. WITH HIGH PRESSURE BUILDING OVER THE WESTERN GREAT
LAKES TONIGHT...THE DRIER AIR/CLEAR SKIES SHOULD CONTINUE TO BLEED
INTO SOUTHEAST MICHIGAN...BUT PROBABLY STRUGGLE TO ADVANCE MUCH PAST
U.S. 23. LONG FETCHED NORTHERLY FLOW AND LOW LEVEL CONVERGENCE
FORECASTED BY 12Z NAM OVER THUMB REGION THIS EVENING SHOULD
MAINTAIN...OR ALLOW FOR REDEVELOPMENT OF ACTIVITY. STILL...THE
OVERALL DRY ENVIRONMENT AND LOW INVERSION HEIGHTS WILL TEMPER
ACTIVITY...AND EXPECTING A VERY NARROW BAND WITH SOME MOVEMENT...AND
THUS ANTICIPATING ACCUMULATIONS BELOW 1 INCH.

WITH TEMPERATURES STILL HOLDING THE 20S THIS AFTERNOON...MINS IN THE
LOW TO MID TEENS SHOULD BE NO PROBLEM...WITH THE POTENTIAL FOR
SINGLE NUMBERS IF THAT CLEARING LINE ADVANCES EAST OVERNIGHT. RECORD
LOWS FOR MARCH 28TH ARE GENERALLY IN THE LOWER SINGLE NUMBERS AND
ARE LIKELY OUT OF REACH AS WINDS WILL PROBABLY NOT GO CALM EVEN IF
WE DO TOTALLY CLEAR OUT.

LONG TERM...

LONGWAVE TROUGH CURRENTLY CENTERED NEAR MICHIGAN AND INDIANA WILL
COMPACT AND MOVE EASTWARD...LEADING TO A 500MB HEIGHT RECOVERY
SUNDAY THROUGH THE EXTENDED PERIOD. SATURDAY WILL CONTINUE TO BE
WELL BELOW NORMAL AS THE H85 TEMP FIELD REMAINS IN THE NEGATIVE
TEENS C. EXPECTING MAXES IN THE MID 30S. DESPITE THESE LOW
VALUES...ANTICYCLONE DIRECTLY OVERHEAD WILL PROVIDE A LIGHT WIND
FIELD AND FULL SUN.  ADDING LATE MARCH INSOLATION...CONDITIONS MAY
NOT FEEL TOO BAD.

ONCE THE SURFACE HIGH MOVES SOUTHEAST OF THE CWA ON
SUNDAY...SOUTHWEST WINDS OF 40-50KT AT H85 WILL QUICKLY USHER IN
WARMER TEMPERATURES. THIS LLJ WILL ALSO ACT TO INCREASE MOISTURE
CONTENT (3-4G/KG) TO AN APPROACHING COLD FRONT. THE WAVE ORIGINATES
WITH PACIFIC MOISTURE AND TRANSLATES ACROSS A CONTINENTAL AIRMASS
BEFORE BEING REINFORCED WITH GOM MOISTURE ON SUNDAY. TOUGH CALL ON
PRECIP TYPE WITH THIS SYSTEM AS TOP-DOWN IT FAVORS A COLD CANADIAN
TEMP PROFILE. SURFACE TO H7 HOWEVER...IT SEEMS THE WAA IS TAKING
OVER AND SURFACE TEMPS SHOULD BE AROUND +1C. WHILE THERE IS A CHANCE
THAT RAIN/SNOW MIX OR A 35F SNOW COULD OCCUR...FAVORING THE WARMER
SIDE OF GUIDANCE THAT INDICATES ABOVE FREEZING TEMPS IN THE BOUNDARY
LAYER (FIRST 1500+ FEET). FORECAST THEREFORE CALLING FOR A COLD 0.2
INCH RAIN EVENT SUNDAY AFTERNOON-EVENING.

BRIEF RIDGING ON MONDAY WILL ALLOW FOR DRY CONDITIONS TO PERSIST
ACROSS SOUTHEAST MICHIGAN FOR THE BEGINNING OF NEXT WEEK. ACTIVE
WEATHER QUICKLY RETURNS THOUGH ON MONDAY NIGHT AS A CLIPPER SYSTEM
ROLLS THROUGH THE REGION. TEMPERATURES LOOK TO BE COLD ENOUGH AT
THIS TIME TO SUPPORT ALL SNOW...WHICH COULD RESULT IN A HALF INCH OF
SNOW AT THE VERY LEAST...MAINLY NORTH OF THE M-59 CORRIDOR. THERE IS
STILL SOME DISAGREEMENT IN THE TRACK OF THIS SYSTEM THOUGH...SO
PRECIP TYPE AND AMOUNT IS NOT COMPLETELY CERTAIN. WARMER
TEMPERATURES AND DRY CONDITIONS RETURN ON WEDNESDAY AND LAST INTO
THURSDAY...WHEN THE NEXT POTENTIAL RAIN MAKER ARRIVES.

MARINE...

NORTH WINDS WILL BE SLOW TO RELAX OVER LAKE HURON TONIGHT AS ISOBARS
SPREAD OUT SOME DUE TO INCOMING HIGH PRESSURE. THE LAKE REMAINS
ACTIVE WITH UPPER LEVEL TEMPS STILL VERY COLD (H85 AT -13C)...WHICH
ADDS TO THE HIGHER WINDS OVER THE WATER. LOOK FOR HIGH WAVES
ESPECIALLY NEAR THE THUMB REGION AS THE NORTH FETCH IS FAVORABLE FOR
AMPLIFICATION. WINDS RAMP BACK UP SUNDAY WITH SOME GUSTS TO GALES AS
990MB LOW MOVES JUST NORTH OF THE REGION. SOUTHWEST WINDS WILL USHER
IN WARMER AIR...SO NOT EXPECTING LAKES TO BECOME UNSTABLE.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....DG
SHORT TERM...SF
LONG TERM....MM/RK
MARINE.......MM


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





000
FXUS63 KDTX 280350
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1150 PM EDT FRI MAR 27 2015


.AVIATION...

IT APPEARS ONE LAST SURGE OF LOW LEVEL CLOUDS WILL PIVOT DOWN INTO
THE TERMINALS FROM LAKE HURON WITHIN NORTHEAST FLOW OF 5 TO 10
KNOTS. THIS WILL BRING A PERIOD OF LOWER VFR CIGS FROM KFNT ON
SOUTH. EXPECT CLEARING ON SATURDAY AS HIGH PRESSURE BUILDS INTO THE
AREA WITH WINDS BACKING TO NORTHWEST AND THEN BECOMING LIGHT AND
VARIABLE BY SATURDAY EVENING AS THE CENTER OF THIS HIGH REACHES THE
AREA.

FOR DTW...GENERALLY EXPECT FEW-SCT VFR CONDITIONS...BUT THERE WILL
BE A CHANCE OF A SEVERAL HOUR PERIOD OF BKN CIGS AROUND 5KFT LATE
TONIGHT AS MOISTURE FUNNELS INTO AREA FROM THE THUMB.


//DTW THRESHOLD PROBABILITIES...

* LOW CONFIDENCE IN CEILINGS AROUND 5000 FT THROUGH LATE TONIGHT
  INTO EARLY SATURDAY MORNING.

&&

.PREV DISCUSSION...ISSUED 340 PM EDT FRI MAR 27 2015

SHORT TERM...TONIGHT

GOOD SUBSIDENCE AND DRYING OCCURRING BEHIND UPPER LEVEL TROUGH AXIS
MOVING THROUGH THE CENTRAL GREAT LAKES THIS AFTERNOON...WITH SURFACE
DEW PTS PLUNGING TO AROUND ZERO OVER CENTRAL SECTIONS OF THE
STATE...UNDER MOSTLY CLEAR SKIES. CLOUDS HAVE THINNED OUT OVER
SOUTHEAST MICHIGAN...BUT COLD (NEGATIVE UPPER TEENS AT 850 MB)
NORTHERLY FLOW OFF LAKE HURON IS MAINTAINING JUST ENOUGH MOISTURE TO
MAINTAIN MOSTLY CLOUDY SKIES AND EMBEDDED SNOW SHOWERS. THE ACTIVITY
IS VERY DISORGANIZED...BUT STEEP LOW LEVEL LAPSE RATES HAVE PRODUCED
VERY SMALL INTENSE CELLS...DROPPING VSYBS BRIEFLY BELOW 1 MILE IN
ISOLATED SPOTS. WITH HIGH PRESSURE BUILDING OVER THE WESTERN GREAT
LAKES TONIGHT...THE DRIER AIR/CLEAR SKIES SHOULD CONTINUE TO BLEED
INTO SOUTHEAST MICHIGAN...BUT PROBABLY STRUGGLE TO ADVANCE MUCH PAST
U.S. 23. LONG FETCHED NORTHERLY FLOW AND LOW LEVEL CONVERGENCE
FORECASTED BY 12Z NAM OVER THUMB REGION THIS EVENING SHOULD
MAINTAIN...OR ALLOW FOR REDEVELOPMENT OF ACTIVITY. STILL...THE
OVERALL DRY ENVIRONMENT AND LOW INVERSION HEIGHTS WILL TEMPER
ACTIVITY...AND EXPECTING A VERY NARROW BAND WITH SOME MOVEMENT...AND
THUS ANTICIPATING ACCUMULATIONS BELOW 1 INCH.

WITH TEMPERATURES STILL HOLDING THE 20S THIS AFTERNOON...MINS IN THE
LOW TO MID TEENS SHOULD BE NO PROBLEM...WITH THE POTENTIAL FOR
SINGLE NUMBERS IF THAT CLEARING LINE ADVANCES EAST OVERNIGHT. RECORD
LOWS FOR MARCH 28TH ARE GENERALLY IN THE LOWER SINGLE NUMBERS AND
ARE LIKELY OUT OF REACH AS WINDS WILL PROBABLY NOT GO CALM EVEN IF
WE DO TOTALLY CLEAR OUT.

LONG TERM...

LONGWAVE TROUGH CURRENTLY CENTERED NEAR MICHIGAN AND INDIANA WILL
COMPACT AND MOVE EASTWARD...LEADING TO A 500MB HEIGHT RECOVERY
SUNDAY THROUGH THE EXTENDED PERIOD. SATURDAY WILL CONTINUE TO BE
WELL BELOW NORMAL AS THE H85 TEMP FIELD REMAINS IN THE NEGATIVE
TEENS C. EXPECTING MAXES IN THE MID 30S. DESPITE THESE LOW
VALUES...ANTICYCLONE DIRECTLY OVERHEAD WILL PROVIDE A LIGHT WIND
FIELD AND FULL SUN.  ADDING LATE MARCH INSOLATION...CONDITIONS MAY
NOT FEEL TOO BAD.

ONCE THE SURFACE HIGH MOVES SOUTHEAST OF THE CWA ON
SUNDAY...SOUTHWEST WINDS OF 40-50KT AT H85 WILL QUICKLY USHER IN
WARMER TEMPERATURES. THIS LLJ WILL ALSO ACT TO INCREASE MOISTURE
CONTENT (3-4G/KG) TO AN APPROACHING COLD FRONT. THE WAVE ORIGINATES
WITH PACIFIC MOISTURE AND TRANSLATES ACROSS A CONTINENTAL AIRMASS
BEFORE BEING REINFORCED WITH GOM MOISTURE ON SUNDAY. TOUGH CALL ON
PRECIP TYPE WITH THIS SYSTEM AS TOP-DOWN IT FAVORS A COLD CANADIAN
TEMP PROFILE. SURFACE TO H7 HOWEVER...IT SEEMS THE WAA IS TAKING
OVER AND SURFACE TEMPS SHOULD BE AROUND +1C. WHILE THERE IS A CHANCE
THAT RAIN/SNOW MIX OR A 35F SNOW COULD OCCUR...FAVORING THE WARMER
SIDE OF GUIDANCE THAT INDICATES ABOVE FREEZING TEMPS IN THE BOUNDARY
LAYER (FIRST 1500+ FEET). FORECAST THEREFORE CALLING FOR A COLD 0.2
INCH RAIN EVENT SUNDAY AFTERNOON-EVENING.

BRIEF RIDGING ON MONDAY WILL ALLOW FOR DRY CONDITIONS TO PERSIST
ACROSS SOUTHEAST MICHIGAN FOR THE BEGINNING OF NEXT WEEK. ACTIVE
WEATHER QUICKLY RETURNS THOUGH ON MONDAY NIGHT AS A CLIPPER SYSTEM
ROLLS THROUGH THE REGION. TEMPERATURES LOOK TO BE COLD ENOUGH AT
THIS TIME TO SUPPORT ALL SNOW...WHICH COULD RESULT IN A HALF INCH OF
SNOW AT THE VERY LEAST...MAINLY NORTH OF THE M-59 CORRIDOR. THERE IS
STILL SOME DISAGREEMENT IN THE TRACK OF THIS SYSTEM THOUGH...SO
PRECIP TYPE AND AMOUNT IS NOT COMPLETELY CERTAIN. WARMER
TEMPERATURES AND DRY CONDITIONS RETURN ON WEDNESDAY AND LAST INTO
THURSDAY...WHEN THE NEXT POTENTIAL RAIN MAKER ARRIVES.

MARINE...

NORTH WINDS WILL BE SLOW TO RELAX OVER LAKE HURON TONIGHT AS ISOBARS
SPREAD OUT SOME DUE TO INCOMING HIGH PRESSURE. THE LAKE REMAINS
ACTIVE WITH UPPER LEVEL TEMPS STILL VERY COLD (H85 AT -13C)...WHICH
ADDS TO THE HIGHER WINDS OVER THE WATER. LOOK FOR HIGH WAVES
ESPECIALLY NEAR THE THUMB REGION AS THE NORTH FETCH IS FAVORABLE FOR
AMPLIFICATION. WINDS RAMP BACK UP SUNDAY WITH SOME GUSTS TO GALES AS
990MB LOW MOVES JUST NORTH OF THE REGION. SOUTHWEST WINDS WILL USHER
IN WARMER AIR...SO NOT EXPECTING LAKES TO BECOME UNSTABLE.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....DG
SHORT TERM...SF
LONG TERM....MM/RK
MARINE.......MM


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




000
FXUS63 KDTX 280350
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1150 PM EDT FRI MAR 27 2015


.AVIATION...

IT APPEARS ONE LAST SURGE OF LOW LEVEL CLOUDS WILL PIVOT DOWN INTO
THE TERMINALS FROM LAKE HURON WITHIN NORTHEAST FLOW OF 5 TO 10
KNOTS. THIS WILL BRING A PERIOD OF LOWER VFR CIGS FROM KFNT ON
SOUTH. EXPECT CLEARING ON SATURDAY AS HIGH PRESSURE BUILDS INTO THE
AREA WITH WINDS BACKING TO NORTHWEST AND THEN BECOMING LIGHT AND
VARIABLE BY SATURDAY EVENING AS THE CENTER OF THIS HIGH REACHES THE
AREA.

FOR DTW...GENERALLY EXPECT FEW-SCT VFR CONDITIONS...BUT THERE WILL
BE A CHANCE OF A SEVERAL HOUR PERIOD OF BKN CIGS AROUND 5KFT LATE
TONIGHT AS MOISTURE FUNNELS INTO AREA FROM THE THUMB.


//DTW THRESHOLD PROBABILITIES...

* LOW CONFIDENCE IN CEILINGS AROUND 5000 FT THROUGH LATE TONIGHT
  INTO EARLY SATURDAY MORNING.

&&

.PREV DISCUSSION...ISSUED 340 PM EDT FRI MAR 27 2015

SHORT TERM...TONIGHT

GOOD SUBSIDENCE AND DRYING OCCURRING BEHIND UPPER LEVEL TROUGH AXIS
MOVING THROUGH THE CENTRAL GREAT LAKES THIS AFTERNOON...WITH SURFACE
DEW PTS PLUNGING TO AROUND ZERO OVER CENTRAL SECTIONS OF THE
STATE...UNDER MOSTLY CLEAR SKIES. CLOUDS HAVE THINNED OUT OVER
SOUTHEAST MICHIGAN...BUT COLD (NEGATIVE UPPER TEENS AT 850 MB)
NORTHERLY FLOW OFF LAKE HURON IS MAINTAINING JUST ENOUGH MOISTURE TO
MAINTAIN MOSTLY CLOUDY SKIES AND EMBEDDED SNOW SHOWERS. THE ACTIVITY
IS VERY DISORGANIZED...BUT STEEP LOW LEVEL LAPSE RATES HAVE PRODUCED
VERY SMALL INTENSE CELLS...DROPPING VSYBS BRIEFLY BELOW 1 MILE IN
ISOLATED SPOTS. WITH HIGH PRESSURE BUILDING OVER THE WESTERN GREAT
LAKES TONIGHT...THE DRIER AIR/CLEAR SKIES SHOULD CONTINUE TO BLEED
INTO SOUTHEAST MICHIGAN...BUT PROBABLY STRUGGLE TO ADVANCE MUCH PAST
U.S. 23. LONG FETCHED NORTHERLY FLOW AND LOW LEVEL CONVERGENCE
FORECASTED BY 12Z NAM OVER THUMB REGION THIS EVENING SHOULD
MAINTAIN...OR ALLOW FOR REDEVELOPMENT OF ACTIVITY. STILL...THE
OVERALL DRY ENVIRONMENT AND LOW INVERSION HEIGHTS WILL TEMPER
ACTIVITY...AND EXPECTING A VERY NARROW BAND WITH SOME MOVEMENT...AND
THUS ANTICIPATING ACCUMULATIONS BELOW 1 INCH.

WITH TEMPERATURES STILL HOLDING THE 20S THIS AFTERNOON...MINS IN THE
LOW TO MID TEENS SHOULD BE NO PROBLEM...WITH THE POTENTIAL FOR
SINGLE NUMBERS IF THAT CLEARING LINE ADVANCES EAST OVERNIGHT. RECORD
LOWS FOR MARCH 28TH ARE GENERALLY IN THE LOWER SINGLE NUMBERS AND
ARE LIKELY OUT OF REACH AS WINDS WILL PROBABLY NOT GO CALM EVEN IF
WE DO TOTALLY CLEAR OUT.

LONG TERM...

LONGWAVE TROUGH CURRENTLY CENTERED NEAR MICHIGAN AND INDIANA WILL
COMPACT AND MOVE EASTWARD...LEADING TO A 500MB HEIGHT RECOVERY
SUNDAY THROUGH THE EXTENDED PERIOD. SATURDAY WILL CONTINUE TO BE
WELL BELOW NORMAL AS THE H85 TEMP FIELD REMAINS IN THE NEGATIVE
TEENS C. EXPECTING MAXES IN THE MID 30S. DESPITE THESE LOW
VALUES...ANTICYCLONE DIRECTLY OVERHEAD WILL PROVIDE A LIGHT WIND
FIELD AND FULL SUN.  ADDING LATE MARCH INSOLATION...CONDITIONS MAY
NOT FEEL TOO BAD.

ONCE THE SURFACE HIGH MOVES SOUTHEAST OF THE CWA ON
SUNDAY...SOUTHWEST WINDS OF 40-50KT AT H85 WILL QUICKLY USHER IN
WARMER TEMPERATURES. THIS LLJ WILL ALSO ACT TO INCREASE MOISTURE
CONTENT (3-4G/KG) TO AN APPROACHING COLD FRONT. THE WAVE ORIGINATES
WITH PACIFIC MOISTURE AND TRANSLATES ACROSS A CONTINENTAL AIRMASS
BEFORE BEING REINFORCED WITH GOM MOISTURE ON SUNDAY. TOUGH CALL ON
PRECIP TYPE WITH THIS SYSTEM AS TOP-DOWN IT FAVORS A COLD CANADIAN
TEMP PROFILE. SURFACE TO H7 HOWEVER...IT SEEMS THE WAA IS TAKING
OVER AND SURFACE TEMPS SHOULD BE AROUND +1C. WHILE THERE IS A CHANCE
THAT RAIN/SNOW MIX OR A 35F SNOW COULD OCCUR...FAVORING THE WARMER
SIDE OF GUIDANCE THAT INDICATES ABOVE FREEZING TEMPS IN THE BOUNDARY
LAYER (FIRST 1500+ FEET). FORECAST THEREFORE CALLING FOR A COLD 0.2
INCH RAIN EVENT SUNDAY AFTERNOON-EVENING.

BRIEF RIDGING ON MONDAY WILL ALLOW FOR DRY CONDITIONS TO PERSIST
ACROSS SOUTHEAST MICHIGAN FOR THE BEGINNING OF NEXT WEEK. ACTIVE
WEATHER QUICKLY RETURNS THOUGH ON MONDAY NIGHT AS A CLIPPER SYSTEM
ROLLS THROUGH THE REGION. TEMPERATURES LOOK TO BE COLD ENOUGH AT
THIS TIME TO SUPPORT ALL SNOW...WHICH COULD RESULT IN A HALF INCH OF
SNOW AT THE VERY LEAST...MAINLY NORTH OF THE M-59 CORRIDOR. THERE IS
STILL SOME DISAGREEMENT IN THE TRACK OF THIS SYSTEM THOUGH...SO
PRECIP TYPE AND AMOUNT IS NOT COMPLETELY CERTAIN. WARMER
TEMPERATURES AND DRY CONDITIONS RETURN ON WEDNESDAY AND LAST INTO
THURSDAY...WHEN THE NEXT POTENTIAL RAIN MAKER ARRIVES.

MARINE...

NORTH WINDS WILL BE SLOW TO RELAX OVER LAKE HURON TONIGHT AS ISOBARS
SPREAD OUT SOME DUE TO INCOMING HIGH PRESSURE. THE LAKE REMAINS
ACTIVE WITH UPPER LEVEL TEMPS STILL VERY COLD (H85 AT -13C)...WHICH
ADDS TO THE HIGHER WINDS OVER THE WATER. LOOK FOR HIGH WAVES
ESPECIALLY NEAR THE THUMB REGION AS THE NORTH FETCH IS FAVORABLE FOR
AMPLIFICATION. WINDS RAMP BACK UP SUNDAY WITH SOME GUSTS TO GALES AS
990MB LOW MOVES JUST NORTH OF THE REGION. SOUTHWEST WINDS WILL USHER
IN WARMER AIR...SO NOT EXPECTING LAKES TO BECOME UNSTABLE.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....DG
SHORT TERM...SF
LONG TERM....MM/RK
MARINE.......MM


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





000
FXUS63 KDTX 272304
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
704 PM EDT FRI MAR 27 2015


.AVIATION...

SCT-BKN STRATO-CU/CUMULUS DECK WILL GRADUALLY ERODE THIS EVENING AS
DRIER LOW LEVEL AIR WORKS INTO THE AREA. UNTIL THEN...OCCASIONAL
MVFR TO LOWER VFR CIGS WILL BE POSSIBLE. A BACKDOOR FRONT FROM LAKE
HURON WILL BRING A PERIOD OF NORTHEAST FLOW AT 10 KNOTS OR SLIGHTLY
MORE EARLY IN THE FORECAST...BUT OVERALL WINDS WILL BE FROM THE NNW
AT UNDER 10 KNOTS TONIGHT INTO SATURDAY.

FOR DTW...BKN LOWER VFR DECK IN THE 5-6KFT RANGE WILL FADE DURING
THE EVENING WITH MAINLY CLEAR SKIES THEREAFTER.


//DTW THRESHOLD PROBABILITIES...

* MEDIUM CONFIDENCE IN CEILINGS AT AROUND 5000 FT THROUGH 03Z THIS
  EVENING.

&&

.PREV DISCUSSION...ISSUED 340 PM EDT FRI MAR 27 2015

SHORT TERM...TONIGHT

GOOD SUBSIDENCE AND DRYING OCCURRING BEHIND UPPER LEVEL TROUGH AXIS
MOVING THROUGH THE CENTRAL GREAT LAKES THIS AFTERNOON...WITH SURFACE
DEW PTS PLUNGING TO AROUND ZERO OVER CENTRAL SECTIONS OF THE
STATE...UNDER MOSTLY CLEAR SKIES. CLOUDS HAVE THINNED OUT OVER
SOUTHEAST MICHIGAN...BUT COLD (NEGATIVE UPPER TEENS AT 850 MB)
NORTHERLY FLOW OFF LAKE HURON IS MAINTAINING JUST ENOUGH MOISTURE TO
MAINTAIN MOSTLY CLOUDY SKIES AND EMBEDDED SNOW SHOWERS. THE ACTIVITY
IS VERY DISORGANIZED...BUT STEEP LOW LEVEL LAPSE RATES HAVE PRODUCED
VERY SMALL INTENSE CELLS...DROPPING VSYBS BRIEFLY BELOW 1 MILE IN
ISOLATED SPOTS. WITH HIGH PRESSURE BUILDING OVER THE WESTERN GREAT
LAKES TONIGHT...THE DRIER AIR/CLEAR SKIES SHOULD CONTINUE TO BLEED
INTO SOUTHEAST MICHIGAN...BUT PROBABLY STRUGGLE TO ADVANCE MUCH PAST
U.S. 23. LONG FETCHED NORTHERLY FLOW AND LOW LEVEL CONVERGENCE
FORECASTED BY 12Z NAM OVER THUMB REGION THIS EVENING SHOULD
MAINTAIN...OR ALLOW FOR REDEVELOPMENT OF ACTIVITY. STILL...THE
OVERALL DRY ENVIRONMENT AND LOW INVERSION HEIGHTS WILL TEMPER
ACTIVITY...AND EXPECTING A VERY NARROW BAND WITH SOME MOVEMENT...AND
THUS ANTICIPATING ACCUMULATIONS BELOW 1 INCH.

WITH TEMPERATURES STILL HOLDING THE 20S THIS AFTERNOON...MINS IN THE
LOW TO MID TEENS SHOULD BE NO PROBLEM...WITH THE POTENTIAL FOR
SINGLE NUMBERS IF THAT CLEARING LINE ADVANCES EAST OVERNIGHT. RECORD
LOWS FOR MARCH 28TH ARE GENERALLY IN THE LOWER SINGLE NUMBERS AND
ARE LIKELY OUT OF REACH AS WINDS WILL PROBABLY NOT GO CALM EVEN IF
WE DO TOTALLY CLEAR OUT.

LONG TERM...

LONGWAVE TROUGH CURRENTLY CENTERED NEAR MICHIGAN AND INDIANA WILL
COMPACT AND MOVE EASTWARD...LEADING TO A 500MB HEIGHT RECOVERY
SUNDAY THROUGH THE EXTENDED PERIOD. SATURDAY WILL CONTINUE TO BE
WELL BELOW NORMAL AS THE H85 TEMP FIELD REMAINS IN THE NEGATIVE
TEENS C. EXPECTING MAXES IN THE MID 30S. DESPITE THESE LOW
VALUES...ANTICYCLONE DIRECTLY OVERHEAD WILL PROVIDE A LIGHT WIND
FIELD AND FULL SUN.  ADDING LATE MARCH INSOLATION...CONDITIONS MAY
NOT FEEL TOO BAD.

ONCE THE SURFACE HIGH MOVES SOUTHEAST OF THE CWA ON
SUNDAY...SOUTHWEST WINDS OF 40-50KT AT H85 WILL QUICKLY USHER IN
WARMER TEMPERATURES. THIS LLJ WILL ALSO ACT TO INCREASE MOISTURE
CONTENT (3-4G/KG) TO AN APPROACHING COLD FRONT. THE WAVE ORIGINATES
WITH PACIFIC MOISTURE AND TRANSLATES ACROSS A CONTINENTAL AIRMASS
BEFORE BEING REINFORCED WITH GOM MOISTURE ON SUNDAY. TOUGH CALL ON
PRECIP TYPE WITH THIS SYSTEM AS TOP-DOWN IT FAVORS A COLD CANADIAN
TEMP PROFILE. SURFACE TO H7 HOWEVER...IT SEEMS THE WAA IS TAKING
OVER AND SURFACE TEMPS SHOULD BE AROUND +1C. WHILE THERE IS A CHANCE
THAT RAIN/SNOW MIX OR A 35F SNOW COULD OCCUR...FAVORING THE WARMER
SIDE OF GUIDANCE THAT INDICATES ABOVE FREEZING TEMPS IN THE BOUNDARY
LAYER (FIRST 1500+ FEET). FORECAST THEREFORE CALLING FOR A COLD 0.2
INCH RAIN EVENT SUNDAY AFTERNOON-EVENING.

BRIEF RIDGING ON MONDAY WILL ALLOW FOR DRY CONDITIONS TO PERSIST
ACROSS SOUTHEAST MICHIGAN FOR THE BEGINNING OF NEXT WEEK. ACTIVE
WEATHER QUICKLY RETURNS THOUGH ON MONDAY NIGHT AS A CLIPPER SYSTEM
ROLLS THROUGH THE REGION. TEMPERATURES LOOK TO BE COLD ENOUGH AT
THIS TIME TO SUPPORT ALL SNOW...WHICH COULD RESULT IN A HALF INCH OF
SNOW AT THE VERY LEAST...MAINLY NORTH OF THE M-59 CORRIDOR. THERE IS
STILL SOME DISAGREEMENT IN THE TRACK OF THIS SYSTEM THOUGH...SO
PRECIP TYPE AND AMOUNT IS NOT COMPLETELY CERTAIN. WARMER
TEMPERATURES AND DRY CONDITIONS RETURN ON WEDNESDAY AND LAST INTO
THURSDAY...WHEN THE NEXT POTENTIAL RAIN MAKER ARRIVES.

MARINE...

NORTH WINDS WILL BE SLOW TO RELAX OVER LAKE HURON TONIGHT AS ISOBARS
SPREAD OUT SOME DUE TO INCOMING HIGH PRESSURE. THE LAKE REMAINS
ACTIVE WITH UPPER LEVEL TEMPS STILL VERY COLD (H85 AT -13C)...WHICH
ADDS TO THE HIGHER WINDS OVER THE WATER. LOOK FOR HIGH WAVES
ESPECIALLY NEAR THE THUMB REGION AS THE NORTH FETCH IS FAVORABLE FOR
AMPLIFICATION. WINDS RAMP BACK UP SUNDAY WITH SOME GUSTS TO GALES AS
990MB LOW MOVES JUST NORTH OF THE REGION. SOUTHWEST WINDS WILL USHER
IN WARMER AIR...SO NOT EXPECTING LAKES TO BECOME UNSTABLE.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....DG
SHORT TERM...SF
LONG TERM....MM/RK
MARINE.......MM


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




000
FXUS63 KDTX 272304
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
704 PM EDT FRI MAR 27 2015


.AVIATION...

SCT-BKN STRATO-CU/CUMULUS DECK WILL GRADUALLY ERODE THIS EVENING AS
DRIER LOW LEVEL AIR WORKS INTO THE AREA. UNTIL THEN...OCCASIONAL
MVFR TO LOWER VFR CIGS WILL BE POSSIBLE. A BACKDOOR FRONT FROM LAKE
HURON WILL BRING A PERIOD OF NORTHEAST FLOW AT 10 KNOTS OR SLIGHTLY
MORE EARLY IN THE FORECAST...BUT OVERALL WINDS WILL BE FROM THE NNW
AT UNDER 10 KNOTS TONIGHT INTO SATURDAY.

FOR DTW...BKN LOWER VFR DECK IN THE 5-6KFT RANGE WILL FADE DURING
THE EVENING WITH MAINLY CLEAR SKIES THEREAFTER.


//DTW THRESHOLD PROBABILITIES...

* MEDIUM CONFIDENCE IN CEILINGS AT AROUND 5000 FT THROUGH 03Z THIS
  EVENING.

&&

.PREV DISCUSSION...ISSUED 340 PM EDT FRI MAR 27 2015

SHORT TERM...TONIGHT

GOOD SUBSIDENCE AND DRYING OCCURRING BEHIND UPPER LEVEL TROUGH AXIS
MOVING THROUGH THE CENTRAL GREAT LAKES THIS AFTERNOON...WITH SURFACE
DEW PTS PLUNGING TO AROUND ZERO OVER CENTRAL SECTIONS OF THE
STATE...UNDER MOSTLY CLEAR SKIES. CLOUDS HAVE THINNED OUT OVER
SOUTHEAST MICHIGAN...BUT COLD (NEGATIVE UPPER TEENS AT 850 MB)
NORTHERLY FLOW OFF LAKE HURON IS MAINTAINING JUST ENOUGH MOISTURE TO
MAINTAIN MOSTLY CLOUDY SKIES AND EMBEDDED SNOW SHOWERS. THE ACTIVITY
IS VERY DISORGANIZED...BUT STEEP LOW LEVEL LAPSE RATES HAVE PRODUCED
VERY SMALL INTENSE CELLS...DROPPING VSYBS BRIEFLY BELOW 1 MILE IN
ISOLATED SPOTS. WITH HIGH PRESSURE BUILDING OVER THE WESTERN GREAT
LAKES TONIGHT...THE DRIER AIR/CLEAR SKIES SHOULD CONTINUE TO BLEED
INTO SOUTHEAST MICHIGAN...BUT PROBABLY STRUGGLE TO ADVANCE MUCH PAST
U.S. 23. LONG FETCHED NORTHERLY FLOW AND LOW LEVEL CONVERGENCE
FORECASTED BY 12Z NAM OVER THUMB REGION THIS EVENING SHOULD
MAINTAIN...OR ALLOW FOR REDEVELOPMENT OF ACTIVITY. STILL...THE
OVERALL DRY ENVIRONMENT AND LOW INVERSION HEIGHTS WILL TEMPER
ACTIVITY...AND EXPECTING A VERY NARROW BAND WITH SOME MOVEMENT...AND
THUS ANTICIPATING ACCUMULATIONS BELOW 1 INCH.

WITH TEMPERATURES STILL HOLDING THE 20S THIS AFTERNOON...MINS IN THE
LOW TO MID TEENS SHOULD BE NO PROBLEM...WITH THE POTENTIAL FOR
SINGLE NUMBERS IF THAT CLEARING LINE ADVANCES EAST OVERNIGHT. RECORD
LOWS FOR MARCH 28TH ARE GENERALLY IN THE LOWER SINGLE NUMBERS AND
ARE LIKELY OUT OF REACH AS WINDS WILL PROBABLY NOT GO CALM EVEN IF
WE DO TOTALLY CLEAR OUT.

LONG TERM...

LONGWAVE TROUGH CURRENTLY CENTERED NEAR MICHIGAN AND INDIANA WILL
COMPACT AND MOVE EASTWARD...LEADING TO A 500MB HEIGHT RECOVERY
SUNDAY THROUGH THE EXTENDED PERIOD. SATURDAY WILL CONTINUE TO BE
WELL BELOW NORMAL AS THE H85 TEMP FIELD REMAINS IN THE NEGATIVE
TEENS C. EXPECTING MAXES IN THE MID 30S. DESPITE THESE LOW
VALUES...ANTICYCLONE DIRECTLY OVERHEAD WILL PROVIDE A LIGHT WIND
FIELD AND FULL SUN.  ADDING LATE MARCH INSOLATION...CONDITIONS MAY
NOT FEEL TOO BAD.

ONCE THE SURFACE HIGH MOVES SOUTHEAST OF THE CWA ON
SUNDAY...SOUTHWEST WINDS OF 40-50KT AT H85 WILL QUICKLY USHER IN
WARMER TEMPERATURES. THIS LLJ WILL ALSO ACT TO INCREASE MOISTURE
CONTENT (3-4G/KG) TO AN APPROACHING COLD FRONT. THE WAVE ORIGINATES
WITH PACIFIC MOISTURE AND TRANSLATES ACROSS A CONTINENTAL AIRMASS
BEFORE BEING REINFORCED WITH GOM MOISTURE ON SUNDAY. TOUGH CALL ON
PRECIP TYPE WITH THIS SYSTEM AS TOP-DOWN IT FAVORS A COLD CANADIAN
TEMP PROFILE. SURFACE TO H7 HOWEVER...IT SEEMS THE WAA IS TAKING
OVER AND SURFACE TEMPS SHOULD BE AROUND +1C. WHILE THERE IS A CHANCE
THAT RAIN/SNOW MIX OR A 35F SNOW COULD OCCUR...FAVORING THE WARMER
SIDE OF GUIDANCE THAT INDICATES ABOVE FREEZING TEMPS IN THE BOUNDARY
LAYER (FIRST 1500+ FEET). FORECAST THEREFORE CALLING FOR A COLD 0.2
INCH RAIN EVENT SUNDAY AFTERNOON-EVENING.

BRIEF RIDGING ON MONDAY WILL ALLOW FOR DRY CONDITIONS TO PERSIST
ACROSS SOUTHEAST MICHIGAN FOR THE BEGINNING OF NEXT WEEK. ACTIVE
WEATHER QUICKLY RETURNS THOUGH ON MONDAY NIGHT AS A CLIPPER SYSTEM
ROLLS THROUGH THE REGION. TEMPERATURES LOOK TO BE COLD ENOUGH AT
THIS TIME TO SUPPORT ALL SNOW...WHICH COULD RESULT IN A HALF INCH OF
SNOW AT THE VERY LEAST...MAINLY NORTH OF THE M-59 CORRIDOR. THERE IS
STILL SOME DISAGREEMENT IN THE TRACK OF THIS SYSTEM THOUGH...SO
PRECIP TYPE AND AMOUNT IS NOT COMPLETELY CERTAIN. WARMER
TEMPERATURES AND DRY CONDITIONS RETURN ON WEDNESDAY AND LAST INTO
THURSDAY...WHEN THE NEXT POTENTIAL RAIN MAKER ARRIVES.

MARINE...

NORTH WINDS WILL BE SLOW TO RELAX OVER LAKE HURON TONIGHT AS ISOBARS
SPREAD OUT SOME DUE TO INCOMING HIGH PRESSURE. THE LAKE REMAINS
ACTIVE WITH UPPER LEVEL TEMPS STILL VERY COLD (H85 AT -13C)...WHICH
ADDS TO THE HIGHER WINDS OVER THE WATER. LOOK FOR HIGH WAVES
ESPECIALLY NEAR THE THUMB REGION AS THE NORTH FETCH IS FAVORABLE FOR
AMPLIFICATION. WINDS RAMP BACK UP SUNDAY WITH SOME GUSTS TO GALES AS
990MB LOW MOVES JUST NORTH OF THE REGION. SOUTHWEST WINDS WILL USHER
IN WARMER AIR...SO NOT EXPECTING LAKES TO BECOME UNSTABLE.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....DG
SHORT TERM...SF
LONG TERM....MM/RK
MARINE.......MM


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





000
FXUS63 KDTX 272304
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
704 PM EDT FRI MAR 27 2015


.AVIATION...

SCT-BKN STRATO-CU/CUMULUS DECK WILL GRADUALLY ERODE THIS EVENING AS
DRIER LOW LEVEL AIR WORKS INTO THE AREA. UNTIL THEN...OCCASIONAL
MVFR TO LOWER VFR CIGS WILL BE POSSIBLE. A BACKDOOR FRONT FROM LAKE
HURON WILL BRING A PERIOD OF NORTHEAST FLOW AT 10 KNOTS OR SLIGHTLY
MORE EARLY IN THE FORECAST...BUT OVERALL WINDS WILL BE FROM THE NNW
AT UNDER 10 KNOTS TONIGHT INTO SATURDAY.

FOR DTW...BKN LOWER VFR DECK IN THE 5-6KFT RANGE WILL FADE DURING
THE EVENING WITH MAINLY CLEAR SKIES THEREAFTER.


//DTW THRESHOLD PROBABILITIES...

* MEDIUM CONFIDENCE IN CEILINGS AT AROUND 5000 FT THROUGH 03Z THIS
  EVENING.

&&

.PREV DISCUSSION...ISSUED 340 PM EDT FRI MAR 27 2015

SHORT TERM...TONIGHT

GOOD SUBSIDENCE AND DRYING OCCURRING BEHIND UPPER LEVEL TROUGH AXIS
MOVING THROUGH THE CENTRAL GREAT LAKES THIS AFTERNOON...WITH SURFACE
DEW PTS PLUNGING TO AROUND ZERO OVER CENTRAL SECTIONS OF THE
STATE...UNDER MOSTLY CLEAR SKIES. CLOUDS HAVE THINNED OUT OVER
SOUTHEAST MICHIGAN...BUT COLD (NEGATIVE UPPER TEENS AT 850 MB)
NORTHERLY FLOW OFF LAKE HURON IS MAINTAINING JUST ENOUGH MOISTURE TO
MAINTAIN MOSTLY CLOUDY SKIES AND EMBEDDED SNOW SHOWERS. THE ACTIVITY
IS VERY DISORGANIZED...BUT STEEP LOW LEVEL LAPSE RATES HAVE PRODUCED
VERY SMALL INTENSE CELLS...DROPPING VSYBS BRIEFLY BELOW 1 MILE IN
ISOLATED SPOTS. WITH HIGH PRESSURE BUILDING OVER THE WESTERN GREAT
LAKES TONIGHT...THE DRIER AIR/CLEAR SKIES SHOULD CONTINUE TO BLEED
INTO SOUTHEAST MICHIGAN...BUT PROBABLY STRUGGLE TO ADVANCE MUCH PAST
U.S. 23. LONG FETCHED NORTHERLY FLOW AND LOW LEVEL CONVERGENCE
FORECASTED BY 12Z NAM OVER THUMB REGION THIS EVENING SHOULD
MAINTAIN...OR ALLOW FOR REDEVELOPMENT OF ACTIVITY. STILL...THE
OVERALL DRY ENVIRONMENT AND LOW INVERSION HEIGHTS WILL TEMPER
ACTIVITY...AND EXPECTING A VERY NARROW BAND WITH SOME MOVEMENT...AND
THUS ANTICIPATING ACCUMULATIONS BELOW 1 INCH.

WITH TEMPERATURES STILL HOLDING THE 20S THIS AFTERNOON...MINS IN THE
LOW TO MID TEENS SHOULD BE NO PROBLEM...WITH THE POTENTIAL FOR
SINGLE NUMBERS IF THAT CLEARING LINE ADVANCES EAST OVERNIGHT. RECORD
LOWS FOR MARCH 28TH ARE GENERALLY IN THE LOWER SINGLE NUMBERS AND
ARE LIKELY OUT OF REACH AS WINDS WILL PROBABLY NOT GO CALM EVEN IF
WE DO TOTALLY CLEAR OUT.

LONG TERM...

LONGWAVE TROUGH CURRENTLY CENTERED NEAR MICHIGAN AND INDIANA WILL
COMPACT AND MOVE EASTWARD...LEADING TO A 500MB HEIGHT RECOVERY
SUNDAY THROUGH THE EXTENDED PERIOD. SATURDAY WILL CONTINUE TO BE
WELL BELOW NORMAL AS THE H85 TEMP FIELD REMAINS IN THE NEGATIVE
TEENS C. EXPECTING MAXES IN THE MID 30S. DESPITE THESE LOW
VALUES...ANTICYCLONE DIRECTLY OVERHEAD WILL PROVIDE A LIGHT WIND
FIELD AND FULL SUN.  ADDING LATE MARCH INSOLATION...CONDITIONS MAY
NOT FEEL TOO BAD.

ONCE THE SURFACE HIGH MOVES SOUTHEAST OF THE CWA ON
SUNDAY...SOUTHWEST WINDS OF 40-50KT AT H85 WILL QUICKLY USHER IN
WARMER TEMPERATURES. THIS LLJ WILL ALSO ACT TO INCREASE MOISTURE
CONTENT (3-4G/KG) TO AN APPROACHING COLD FRONT. THE WAVE ORIGINATES
WITH PACIFIC MOISTURE AND TRANSLATES ACROSS A CONTINENTAL AIRMASS
BEFORE BEING REINFORCED WITH GOM MOISTURE ON SUNDAY. TOUGH CALL ON
PRECIP TYPE WITH THIS SYSTEM AS TOP-DOWN IT FAVORS A COLD CANADIAN
TEMP PROFILE. SURFACE TO H7 HOWEVER...IT SEEMS THE WAA IS TAKING
OVER AND SURFACE TEMPS SHOULD BE AROUND +1C. WHILE THERE IS A CHANCE
THAT RAIN/SNOW MIX OR A 35F SNOW COULD OCCUR...FAVORING THE WARMER
SIDE OF GUIDANCE THAT INDICATES ABOVE FREEZING TEMPS IN THE BOUNDARY
LAYER (FIRST 1500+ FEET). FORECAST THEREFORE CALLING FOR A COLD 0.2
INCH RAIN EVENT SUNDAY AFTERNOON-EVENING.

BRIEF RIDGING ON MONDAY WILL ALLOW FOR DRY CONDITIONS TO PERSIST
ACROSS SOUTHEAST MICHIGAN FOR THE BEGINNING OF NEXT WEEK. ACTIVE
WEATHER QUICKLY RETURNS THOUGH ON MONDAY NIGHT AS A CLIPPER SYSTEM
ROLLS THROUGH THE REGION. TEMPERATURES LOOK TO BE COLD ENOUGH AT
THIS TIME TO SUPPORT ALL SNOW...WHICH COULD RESULT IN A HALF INCH OF
SNOW AT THE VERY LEAST...MAINLY NORTH OF THE M-59 CORRIDOR. THERE IS
STILL SOME DISAGREEMENT IN THE TRACK OF THIS SYSTEM THOUGH...SO
PRECIP TYPE AND AMOUNT IS NOT COMPLETELY CERTAIN. WARMER
TEMPERATURES AND DRY CONDITIONS RETURN ON WEDNESDAY AND LAST INTO
THURSDAY...WHEN THE NEXT POTENTIAL RAIN MAKER ARRIVES.

MARINE...

NORTH WINDS WILL BE SLOW TO RELAX OVER LAKE HURON TONIGHT AS ISOBARS
SPREAD OUT SOME DUE TO INCOMING HIGH PRESSURE. THE LAKE REMAINS
ACTIVE WITH UPPER LEVEL TEMPS STILL VERY COLD (H85 AT -13C)...WHICH
ADDS TO THE HIGHER WINDS OVER THE WATER. LOOK FOR HIGH WAVES
ESPECIALLY NEAR THE THUMB REGION AS THE NORTH FETCH IS FAVORABLE FOR
AMPLIFICATION. WINDS RAMP BACK UP SUNDAY WITH SOME GUSTS TO GALES AS
990MB LOW MOVES JUST NORTH OF THE REGION. SOUTHWEST WINDS WILL USHER
IN WARMER AIR...SO NOT EXPECTING LAKES TO BECOME UNSTABLE.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....DG
SHORT TERM...SF
LONG TERM....MM/RK
MARINE.......MM


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





000
FXUS63 KDTX 272304
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
704 PM EDT FRI MAR 27 2015


.AVIATION...

SCT-BKN STRATO-CU/CUMULUS DECK WILL GRADUALLY ERODE THIS EVENING AS
DRIER LOW LEVEL AIR WORKS INTO THE AREA. UNTIL THEN...OCCASIONAL
MVFR TO LOWER VFR CIGS WILL BE POSSIBLE. A BACKDOOR FRONT FROM LAKE
HURON WILL BRING A PERIOD OF NORTHEAST FLOW AT 10 KNOTS OR SLIGHTLY
MORE EARLY IN THE FORECAST...BUT OVERALL WINDS WILL BE FROM THE NNW
AT UNDER 10 KNOTS TONIGHT INTO SATURDAY.

FOR DTW...BKN LOWER VFR DECK IN THE 5-6KFT RANGE WILL FADE DURING
THE EVENING WITH MAINLY CLEAR SKIES THEREAFTER.


//DTW THRESHOLD PROBABILITIES...

* MEDIUM CONFIDENCE IN CEILINGS AT AROUND 5000 FT THROUGH 03Z THIS
  EVENING.

&&

.PREV DISCUSSION...ISSUED 340 PM EDT FRI MAR 27 2015

SHORT TERM...TONIGHT

GOOD SUBSIDENCE AND DRYING OCCURRING BEHIND UPPER LEVEL TROUGH AXIS
MOVING THROUGH THE CENTRAL GREAT LAKES THIS AFTERNOON...WITH SURFACE
DEW PTS PLUNGING TO AROUND ZERO OVER CENTRAL SECTIONS OF THE
STATE...UNDER MOSTLY CLEAR SKIES. CLOUDS HAVE THINNED OUT OVER
SOUTHEAST MICHIGAN...BUT COLD (NEGATIVE UPPER TEENS AT 850 MB)
NORTHERLY FLOW OFF LAKE HURON IS MAINTAINING JUST ENOUGH MOISTURE TO
MAINTAIN MOSTLY CLOUDY SKIES AND EMBEDDED SNOW SHOWERS. THE ACTIVITY
IS VERY DISORGANIZED...BUT STEEP LOW LEVEL LAPSE RATES HAVE PRODUCED
VERY SMALL INTENSE CELLS...DROPPING VSYBS BRIEFLY BELOW 1 MILE IN
ISOLATED SPOTS. WITH HIGH PRESSURE BUILDING OVER THE WESTERN GREAT
LAKES TONIGHT...THE DRIER AIR/CLEAR SKIES SHOULD CONTINUE TO BLEED
INTO SOUTHEAST MICHIGAN...BUT PROBABLY STRUGGLE TO ADVANCE MUCH PAST
U.S. 23. LONG FETCHED NORTHERLY FLOW AND LOW LEVEL CONVERGENCE
FORECASTED BY 12Z NAM OVER THUMB REGION THIS EVENING SHOULD
MAINTAIN...OR ALLOW FOR REDEVELOPMENT OF ACTIVITY. STILL...THE
OVERALL DRY ENVIRONMENT AND LOW INVERSION HEIGHTS WILL TEMPER
ACTIVITY...AND EXPECTING A VERY NARROW BAND WITH SOME MOVEMENT...AND
THUS ANTICIPATING ACCUMULATIONS BELOW 1 INCH.

WITH TEMPERATURES STILL HOLDING THE 20S THIS AFTERNOON...MINS IN THE
LOW TO MID TEENS SHOULD BE NO PROBLEM...WITH THE POTENTIAL FOR
SINGLE NUMBERS IF THAT CLEARING LINE ADVANCES EAST OVERNIGHT. RECORD
LOWS FOR MARCH 28TH ARE GENERALLY IN THE LOWER SINGLE NUMBERS AND
ARE LIKELY OUT OF REACH AS WINDS WILL PROBABLY NOT GO CALM EVEN IF
WE DO TOTALLY CLEAR OUT.

LONG TERM...

LONGWAVE TROUGH CURRENTLY CENTERED NEAR MICHIGAN AND INDIANA WILL
COMPACT AND MOVE EASTWARD...LEADING TO A 500MB HEIGHT RECOVERY
SUNDAY THROUGH THE EXTENDED PERIOD. SATURDAY WILL CONTINUE TO BE
WELL BELOW NORMAL AS THE H85 TEMP FIELD REMAINS IN THE NEGATIVE
TEENS C. EXPECTING MAXES IN THE MID 30S. DESPITE THESE LOW
VALUES...ANTICYCLONE DIRECTLY OVERHEAD WILL PROVIDE A LIGHT WIND
FIELD AND FULL SUN.  ADDING LATE MARCH INSOLATION...CONDITIONS MAY
NOT FEEL TOO BAD.

ONCE THE SURFACE HIGH MOVES SOUTHEAST OF THE CWA ON
SUNDAY...SOUTHWEST WINDS OF 40-50KT AT H85 WILL QUICKLY USHER IN
WARMER TEMPERATURES. THIS LLJ WILL ALSO ACT TO INCREASE MOISTURE
CONTENT (3-4G/KG) TO AN APPROACHING COLD FRONT. THE WAVE ORIGINATES
WITH PACIFIC MOISTURE AND TRANSLATES ACROSS A CONTINENTAL AIRMASS
BEFORE BEING REINFORCED WITH GOM MOISTURE ON SUNDAY. TOUGH CALL ON
PRECIP TYPE WITH THIS SYSTEM AS TOP-DOWN IT FAVORS A COLD CANADIAN
TEMP PROFILE. SURFACE TO H7 HOWEVER...IT SEEMS THE WAA IS TAKING
OVER AND SURFACE TEMPS SHOULD BE AROUND +1C. WHILE THERE IS A CHANCE
THAT RAIN/SNOW MIX OR A 35F SNOW COULD OCCUR...FAVORING THE WARMER
SIDE OF GUIDANCE THAT INDICATES ABOVE FREEZING TEMPS IN THE BOUNDARY
LAYER (FIRST 1500+ FEET). FORECAST THEREFORE CALLING FOR A COLD 0.2
INCH RAIN EVENT SUNDAY AFTERNOON-EVENING.

BRIEF RIDGING ON MONDAY WILL ALLOW FOR DRY CONDITIONS TO PERSIST
ACROSS SOUTHEAST MICHIGAN FOR THE BEGINNING OF NEXT WEEK. ACTIVE
WEATHER QUICKLY RETURNS THOUGH ON MONDAY NIGHT AS A CLIPPER SYSTEM
ROLLS THROUGH THE REGION. TEMPERATURES LOOK TO BE COLD ENOUGH AT
THIS TIME TO SUPPORT ALL SNOW...WHICH COULD RESULT IN A HALF INCH OF
SNOW AT THE VERY LEAST...MAINLY NORTH OF THE M-59 CORRIDOR. THERE IS
STILL SOME DISAGREEMENT IN THE TRACK OF THIS SYSTEM THOUGH...SO
PRECIP TYPE AND AMOUNT IS NOT COMPLETELY CERTAIN. WARMER
TEMPERATURES AND DRY CONDITIONS RETURN ON WEDNESDAY AND LAST INTO
THURSDAY...WHEN THE NEXT POTENTIAL RAIN MAKER ARRIVES.

MARINE...

NORTH WINDS WILL BE SLOW TO RELAX OVER LAKE HURON TONIGHT AS ISOBARS
SPREAD OUT SOME DUE TO INCOMING HIGH PRESSURE. THE LAKE REMAINS
ACTIVE WITH UPPER LEVEL TEMPS STILL VERY COLD (H85 AT -13C)...WHICH
ADDS TO THE HIGHER WINDS OVER THE WATER. LOOK FOR HIGH WAVES
ESPECIALLY NEAR THE THUMB REGION AS THE NORTH FETCH IS FAVORABLE FOR
AMPLIFICATION. WINDS RAMP BACK UP SUNDAY WITH SOME GUSTS TO GALES AS
990MB LOW MOVES JUST NORTH OF THE REGION. SOUTHWEST WINDS WILL USHER
IN WARMER AIR...SO NOT EXPECTING LAKES TO BECOME UNSTABLE.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....DG
SHORT TERM...SF
LONG TERM....MM/RK
MARINE.......MM


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




000
FXUS63 KDTX 271940
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
340 PM EDT FRI MAR 27 2015

.SHORT TERM...TONIGHT

GOOD SUBSIDENCE AND DRYING OCCURRING BEHIND UPPER LEVEL TROUGH AXIS
MOVING THROUGH THE CENTRAL GREAT LAKES THIS AFTERNOON...WITH SURFACE
DEW PTS PLUNGING TO AROUND ZERO OVER CENTRAL SECTIONS OF THE
STATE...UNDER MOSTLY CLEAR SKIES. CLOUDS HAVE THINNED OUT OVER
SOUTHEAST MICHIGAN...BUT COLD (NEGATIVE UPPER TEENS AT 850 MB)
NORTHERLY FLOW OFF LAKE HURON IS MAINTAINING JUST ENOUGH MOISTURE TO
MAINTAIN MOSTLY CLOUDY SKIES AND EMBEDDED SNOW SHOWERS. THE ACTIVITY
IS VERY DISORGANIZED...BUT STEEP LOW LEVEL LAPSE RATES HAVE PRODUCED
VERY SMALL INTENSE CELLS...DROPPING VSYBS BRIEFLY BELOW 1 MILE IN
ISOLATED SPOTS. WITH HIGH PRESSURE BUILDING OVER THE WESTERN GREAT
LAKES TONIGHT...THE DRIER AIR/CLEAR SKIES SHOULD CONTINUE TO BLEED
INTO SOUTHEAST MICHIGAN...BUT PROBABLY STRUGGLE TO ADVANCE MUCH PAST
U.S. 23. LONG FETCHED NORTHERLY FLOW AND LOW LEVEL CONVERGENCE
FORECASTED BY 12Z NAM OVER THUMB REGION THIS EVENING SHOULD
MAINTAIN...OR ALLOW FOR REDEVELOPMENT OF ACTIVITY. STILL...THE
OVERALL DRY ENVIRONMENT AND LOW INVERSION HEIGHTS WILL TEMPER
ACTIVITY...AND EXPECTING A VERY NARROW BAND WITH SOME MOVEMENT...AND
THUS ANTICIPATING ACCUMULATIONS BELOW 1 INCH.

WITH TEMPERATURES STILL HOLDING THE 20S THIS AFTERNOON...MINS IN THE
LOW TO MID TEENS SHOULD BE NO PROBLEM...WITH THE POTENTIAL FOR
SINGLE NUMBERS IF THAT CLEARING LINE ADVANCES EAST OVERNIGHT. RECORD
LOWS FOR MARCH 28TH ARE GENERALLY IN THE LOWER SINGLE NUMBERS AND
ARE LIKELY OUT OF REACH AS WINDS WILL PROBABLY NOT GO CALM EVEN IF
WE DO TOTALLY CLEAR OUT.

&&

.LONG TERM...

LONGWAVE TROUGH CURRENTLY CENTERED NEAR MICHIGAN AND INDIANA WILL
COMPACT AND MOVE EASTWARD...LEADING TO A 500MB HEIGHT RECOVERY
SUNDAY THROUGH THE EXTENDED PERIOD. SATURDAY WILL CONTINUE TO BE
WELL BELOW NORMAL AS THE H85 TEMP FIELD REMAINS IN THE NEGATIVE
TEENS C. EXPECTING MAXES IN THE MID 30S. DESPITE THESE LOW
VALUES...ANTICYCLONE DIRECTLY OVERHEAD WILL PROVIDE A LIGHT WIND
FIELD AND FULL SUN.  ADDING LATE MARCH INSOLATION...CONDITIONS MAY
NOT FEEL TOO BAD.

ONCE THE SURFACE HIGH MOVES SOUTHEAST OF THE CWA ON
SUNDAY...SOUTHWEST WINDS OF 40-50KT AT H85 WILL QUICKLY USHER IN
WARMER TEMPERATURES. THIS LLJ WILL ALSO ACT TO INCREASE MOISTURE
CONTENT (3-4G/KG) TO AN APPROACHING COLD FRONT. THE WAVE ORIGINATES
WITH PACIFIC MOISTURE AND TRANSLATES ACROSS A CONTINENTAL AIRMASS
BEFORE BEING REINFORCED WITH GOM MOISTURE ON SUNDAY. TOUGH CALL ON
PRECIP TYPE WITH THIS SYSTEM AS TOP-DOWN IT FAVORS A COLD CANADIAN
TEMP PROFILE. SURFACE TO H7 HOWEVER...IT SEEMS THE WAA IS TAKING
OVER AND SURFACE TEMPS SHOULD BE AROUND +1C. WHILE THERE IS A CHANCE
THAT RAIN/SNOW MIX OR A 35F SNOW COULD OCCUR...FAVORING THE WARMER
SIDE OF GUIDANCE THAT INDICATES ABOVE FREEZING TEMPS IN THE BOUNDARY
LAYER (FIRST 1500+ FEET). FORECAST THEREFORE CALLING FOR A COLD 0.2
INCH RAIN EVENT SUNDAY AFTERNOON-EVENING.

BRIEF RIDGING ON MONDAY WILL ALLOW FOR DRY CONDITIONS TO PERSIST
ACROSS SOUTHEAST MICHIGAN FOR THE BEGINNING OF NEXT WEEK. ACTIVE
WEATHER QUICKLY RETURNS THOUGH ON MONDAY NIGHT AS A CLIPPER SYSTEM
ROLLS THROUGH THE REGION. TEMPERATURES LOOK TO BE COLD ENOUGH AT
THIS TIME TO SUPPORT ALL SNOW...WHICH COULD RESULT IN A HALF INCH OF
SNOW AT THE VERY LEAST...MAINLY NORTH OF THE M-59 CORRIDOR. THERE IS
STILL SOME DISAGREEMENT IN THE TRACK OF THIS SYSTEM THOUGH...SO
PRECIP TYPE AND AMOUNT IS NOT COMPLETELY CERTAIN. WARMER
TEMPERATURES AND DRY CONDITIONS RETURN ON WEDNESDAY AND LAST INTO
THURSDAY...WHEN THE NEXT POTENTIAL RAIN MAKER ARRIVES.

&&

.MARINE...

NORTH WINDS WILL BE SLOW TO RELAX OVER LAKE HURON TONIGHT AS ISOBARS
SPREAD OUT SOME DUE TO INCOMING HIGH PRESSURE. THE LAKE REMAINS
ACTIVE WITH UPPER LEVEL TEMPS STILL VERY COLD (H85 AT -13C)...WHICH
ADDS TO THE HIGHER WINDS OVER THE WATER. LOOK FOR HIGH WAVES
ESPECIALLY NEAR THE THUMB REGION AS THE NORTH FETCH IS FAVORABLE FOR
AMPLIFICATION. WINDS RAMP BACK UP SUNDAY WITH SOME GUSTS TO GALES AS
990MB LOW MOVES JUST NORTH OF THE REGION. SOUTHWEST WINDS WILL USHER
IN WARMER AIR...SO NOT EXPECTING LAKES TO BECOME UNSTABLE.

&&

.AVIATION...ISSUED 1226 PM EDT FRI MAR 27 2015

CLEARING TREND WILL ATTEMPT TO WORK IN FROM THE WEST/NORTHWEST AS
SUBSIDENCE OCCURS THIS AFTERNOON BEHIND UPPER LEVEL TROUGH AXIS. DO
THINK MBS WILL SCATTER OR CLEAR OUT. HOWEVER...COLD NORTHERLY FLOW
OFF LAKE HURON WILL TEND TO MAINTAIN LAKE CLOUDS AND EMBEDDED SNOW
SHOWERS FARTHER EAST. FORTUNATELY...CLOUD BASES AND VSBYS SHOULD BE
PREDOMINATELY OF THE LOW VFR VARIETY THROUGH TONIGHT...EVEN IF
CLOUDS DO IN FACT HOLD...WITH JUST LOCALIZED MVFR SNOW
SHOWERS/CEILINGS. SURFACE HIGH PRESSURE BUILDING INTO LOWER MICHIGAN
WILL ALLOW WINDS TO BACK A BIT TO THE NORTHWEST LATE TONIGHT...WHICH
SHOULD SET UP THE TAF SITES FOR MOSTLY CLEAR SKIES TOMORROW.

FOR DTW...LOW VFR CLOUDS AND BRIEF MVFR SNOW SHOWERS WILL DIMINISH
THIS AFTERNOON...WITH CONFIDENCE IN CLOUDS/CEILINGS HOLDING THEN
DIMINISHING THIS EVENING AND TONIGHT...AS DRIER AIR AND HIGH
PRESSURE ATTEMPTS TO BUILD IN FROM THE WEST.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CEILINGS AOB 5000 FT THIS AFTERNOON...MEDIUM
  CONFIDENCE THIS EVENING...LOW CONFIDENCE AFTER MIDNIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

SHORT TERM...SF
LONG TERM....MM/RK
MARINE.......MM
AVIATION.....SF


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




000
FXUS63 KDTX 271940
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
340 PM EDT FRI MAR 27 2015

.SHORT TERM...TONIGHT

GOOD SUBSIDENCE AND DRYING OCCURRING BEHIND UPPER LEVEL TROUGH AXIS
MOVING THROUGH THE CENTRAL GREAT LAKES THIS AFTERNOON...WITH SURFACE
DEW PTS PLUNGING TO AROUND ZERO OVER CENTRAL SECTIONS OF THE
STATE...UNDER MOSTLY CLEAR SKIES. CLOUDS HAVE THINNED OUT OVER
SOUTHEAST MICHIGAN...BUT COLD (NEGATIVE UPPER TEENS AT 850 MB)
NORTHERLY FLOW OFF LAKE HURON IS MAINTAINING JUST ENOUGH MOISTURE TO
MAINTAIN MOSTLY CLOUDY SKIES AND EMBEDDED SNOW SHOWERS. THE ACTIVITY
IS VERY DISORGANIZED...BUT STEEP LOW LEVEL LAPSE RATES HAVE PRODUCED
VERY SMALL INTENSE CELLS...DROPPING VSYBS BRIEFLY BELOW 1 MILE IN
ISOLATED SPOTS. WITH HIGH PRESSURE BUILDING OVER THE WESTERN GREAT
LAKES TONIGHT...THE DRIER AIR/CLEAR SKIES SHOULD CONTINUE TO BLEED
INTO SOUTHEAST MICHIGAN...BUT PROBABLY STRUGGLE TO ADVANCE MUCH PAST
U.S. 23. LONG FETCHED NORTHERLY FLOW AND LOW LEVEL CONVERGENCE
FORECASTED BY 12Z NAM OVER THUMB REGION THIS EVENING SHOULD
MAINTAIN...OR ALLOW FOR REDEVELOPMENT OF ACTIVITY. STILL...THE
OVERALL DRY ENVIRONMENT AND LOW INVERSION HEIGHTS WILL TEMPER
ACTIVITY...AND EXPECTING A VERY NARROW BAND WITH SOME MOVEMENT...AND
THUS ANTICIPATING ACCUMULATIONS BELOW 1 INCH.

WITH TEMPERATURES STILL HOLDING THE 20S THIS AFTERNOON...MINS IN THE
LOW TO MID TEENS SHOULD BE NO PROBLEM...WITH THE POTENTIAL FOR
SINGLE NUMBERS IF THAT CLEARING LINE ADVANCES EAST OVERNIGHT. RECORD
LOWS FOR MARCH 28TH ARE GENERALLY IN THE LOWER SINGLE NUMBERS AND
ARE LIKELY OUT OF REACH AS WINDS WILL PROBABLY NOT GO CALM EVEN IF
WE DO TOTALLY CLEAR OUT.

&&

.LONG TERM...

LONGWAVE TROUGH CURRENTLY CENTERED NEAR MICHIGAN AND INDIANA WILL
COMPACT AND MOVE EASTWARD...LEADING TO A 500MB HEIGHT RECOVERY
SUNDAY THROUGH THE EXTENDED PERIOD. SATURDAY WILL CONTINUE TO BE
WELL BELOW NORMAL AS THE H85 TEMP FIELD REMAINS IN THE NEGATIVE
TEENS C. EXPECTING MAXES IN THE MID 30S. DESPITE THESE LOW
VALUES...ANTICYCLONE DIRECTLY OVERHEAD WILL PROVIDE A LIGHT WIND
FIELD AND FULL SUN.  ADDING LATE MARCH INSOLATION...CONDITIONS MAY
NOT FEEL TOO BAD.

ONCE THE SURFACE HIGH MOVES SOUTHEAST OF THE CWA ON
SUNDAY...SOUTHWEST WINDS OF 40-50KT AT H85 WILL QUICKLY USHER IN
WARMER TEMPERATURES. THIS LLJ WILL ALSO ACT TO INCREASE MOISTURE
CONTENT (3-4G/KG) TO AN APPROACHING COLD FRONT. THE WAVE ORIGINATES
WITH PACIFIC MOISTURE AND TRANSLATES ACROSS A CONTINENTAL AIRMASS
BEFORE BEING REINFORCED WITH GOM MOISTURE ON SUNDAY. TOUGH CALL ON
PRECIP TYPE WITH THIS SYSTEM AS TOP-DOWN IT FAVORS A COLD CANADIAN
TEMP PROFILE. SURFACE TO H7 HOWEVER...IT SEEMS THE WAA IS TAKING
OVER AND SURFACE TEMPS SHOULD BE AROUND +1C. WHILE THERE IS A CHANCE
THAT RAIN/SNOW MIX OR A 35F SNOW COULD OCCUR...FAVORING THE WARMER
SIDE OF GUIDANCE THAT INDICATES ABOVE FREEZING TEMPS IN THE BOUNDARY
LAYER (FIRST 1500+ FEET). FORECAST THEREFORE CALLING FOR A COLD 0.2
INCH RAIN EVENT SUNDAY AFTERNOON-EVENING.

BRIEF RIDGING ON MONDAY WILL ALLOW FOR DRY CONDITIONS TO PERSIST
ACROSS SOUTHEAST MICHIGAN FOR THE BEGINNING OF NEXT WEEK. ACTIVE
WEATHER QUICKLY RETURNS THOUGH ON MONDAY NIGHT AS A CLIPPER SYSTEM
ROLLS THROUGH THE REGION. TEMPERATURES LOOK TO BE COLD ENOUGH AT
THIS TIME TO SUPPORT ALL SNOW...WHICH COULD RESULT IN A HALF INCH OF
SNOW AT THE VERY LEAST...MAINLY NORTH OF THE M-59 CORRIDOR. THERE IS
STILL SOME DISAGREEMENT IN THE TRACK OF THIS SYSTEM THOUGH...SO
PRECIP TYPE AND AMOUNT IS NOT COMPLETELY CERTAIN. WARMER
TEMPERATURES AND DRY CONDITIONS RETURN ON WEDNESDAY AND LAST INTO
THURSDAY...WHEN THE NEXT POTENTIAL RAIN MAKER ARRIVES.

&&

.MARINE...

NORTH WINDS WILL BE SLOW TO RELAX OVER LAKE HURON TONIGHT AS ISOBARS
SPREAD OUT SOME DUE TO INCOMING HIGH PRESSURE. THE LAKE REMAINS
ACTIVE WITH UPPER LEVEL TEMPS STILL VERY COLD (H85 AT -13C)...WHICH
ADDS TO THE HIGHER WINDS OVER THE WATER. LOOK FOR HIGH WAVES
ESPECIALLY NEAR THE THUMB REGION AS THE NORTH FETCH IS FAVORABLE FOR
AMPLIFICATION. WINDS RAMP BACK UP SUNDAY WITH SOME GUSTS TO GALES AS
990MB LOW MOVES JUST NORTH OF THE REGION. SOUTHWEST WINDS WILL USHER
IN WARMER AIR...SO NOT EXPECTING LAKES TO BECOME UNSTABLE.

&&

.AVIATION...ISSUED 1226 PM EDT FRI MAR 27 2015

CLEARING TREND WILL ATTEMPT TO WORK IN FROM THE WEST/NORTHWEST AS
SUBSIDENCE OCCURS THIS AFTERNOON BEHIND UPPER LEVEL TROUGH AXIS. DO
THINK MBS WILL SCATTER OR CLEAR OUT. HOWEVER...COLD NORTHERLY FLOW
OFF LAKE HURON WILL TEND TO MAINTAIN LAKE CLOUDS AND EMBEDDED SNOW
SHOWERS FARTHER EAST. FORTUNATELY...CLOUD BASES AND VSBYS SHOULD BE
PREDOMINATELY OF THE LOW VFR VARIETY THROUGH TONIGHT...EVEN IF
CLOUDS DO IN FACT HOLD...WITH JUST LOCALIZED MVFR SNOW
SHOWERS/CEILINGS. SURFACE HIGH PRESSURE BUILDING INTO LOWER MICHIGAN
WILL ALLOW WINDS TO BACK A BIT TO THE NORTHWEST LATE TONIGHT...WHICH
SHOULD SET UP THE TAF SITES FOR MOSTLY CLEAR SKIES TOMORROW.

FOR DTW...LOW VFR CLOUDS AND BRIEF MVFR SNOW SHOWERS WILL DIMINISH
THIS AFTERNOON...WITH CONFIDENCE IN CLOUDS/CEILINGS HOLDING THEN
DIMINISHING THIS EVENING AND TONIGHT...AS DRIER AIR AND HIGH
PRESSURE ATTEMPTS TO BUILD IN FROM THE WEST.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CEILINGS AOB 5000 FT THIS AFTERNOON...MEDIUM
  CONFIDENCE THIS EVENING...LOW CONFIDENCE AFTER MIDNIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

SHORT TERM...SF
LONG TERM....MM/RK
MARINE.......MM
AVIATION.....SF


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





000
FXUS63 KDTX 271940
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
340 PM EDT FRI MAR 27 2015

.SHORT TERM...TONIGHT

GOOD SUBSIDENCE AND DRYING OCCURRING BEHIND UPPER LEVEL TROUGH AXIS
MOVING THROUGH THE CENTRAL GREAT LAKES THIS AFTERNOON...WITH SURFACE
DEW PTS PLUNGING TO AROUND ZERO OVER CENTRAL SECTIONS OF THE
STATE...UNDER MOSTLY CLEAR SKIES. CLOUDS HAVE THINNED OUT OVER
SOUTHEAST MICHIGAN...BUT COLD (NEGATIVE UPPER TEENS AT 850 MB)
NORTHERLY FLOW OFF LAKE HURON IS MAINTAINING JUST ENOUGH MOISTURE TO
MAINTAIN MOSTLY CLOUDY SKIES AND EMBEDDED SNOW SHOWERS. THE ACTIVITY
IS VERY DISORGANIZED...BUT STEEP LOW LEVEL LAPSE RATES HAVE PRODUCED
VERY SMALL INTENSE CELLS...DROPPING VSYBS BRIEFLY BELOW 1 MILE IN
ISOLATED SPOTS. WITH HIGH PRESSURE BUILDING OVER THE WESTERN GREAT
LAKES TONIGHT...THE DRIER AIR/CLEAR SKIES SHOULD CONTINUE TO BLEED
INTO SOUTHEAST MICHIGAN...BUT PROBABLY STRUGGLE TO ADVANCE MUCH PAST
U.S. 23. LONG FETCHED NORTHERLY FLOW AND LOW LEVEL CONVERGENCE
FORECASTED BY 12Z NAM OVER THUMB REGION THIS EVENING SHOULD
MAINTAIN...OR ALLOW FOR REDEVELOPMENT OF ACTIVITY. STILL...THE
OVERALL DRY ENVIRONMENT AND LOW INVERSION HEIGHTS WILL TEMPER
ACTIVITY...AND EXPECTING A VERY NARROW BAND WITH SOME MOVEMENT...AND
THUS ANTICIPATING ACCUMULATIONS BELOW 1 INCH.

WITH TEMPERATURES STILL HOLDING THE 20S THIS AFTERNOON...MINS IN THE
LOW TO MID TEENS SHOULD BE NO PROBLEM...WITH THE POTENTIAL FOR
SINGLE NUMBERS IF THAT CLEARING LINE ADVANCES EAST OVERNIGHT. RECORD
LOWS FOR MARCH 28TH ARE GENERALLY IN THE LOWER SINGLE NUMBERS AND
ARE LIKELY OUT OF REACH AS WINDS WILL PROBABLY NOT GO CALM EVEN IF
WE DO TOTALLY CLEAR OUT.

&&

.LONG TERM...

LONGWAVE TROUGH CURRENTLY CENTERED NEAR MICHIGAN AND INDIANA WILL
COMPACT AND MOVE EASTWARD...LEADING TO A 500MB HEIGHT RECOVERY
SUNDAY THROUGH THE EXTENDED PERIOD. SATURDAY WILL CONTINUE TO BE
WELL BELOW NORMAL AS THE H85 TEMP FIELD REMAINS IN THE NEGATIVE
TEENS C. EXPECTING MAXES IN THE MID 30S. DESPITE THESE LOW
VALUES...ANTICYCLONE DIRECTLY OVERHEAD WILL PROVIDE A LIGHT WIND
FIELD AND FULL SUN.  ADDING LATE MARCH INSOLATION...CONDITIONS MAY
NOT FEEL TOO BAD.

ONCE THE SURFACE HIGH MOVES SOUTHEAST OF THE CWA ON
SUNDAY...SOUTHWEST WINDS OF 40-50KT AT H85 WILL QUICKLY USHER IN
WARMER TEMPERATURES. THIS LLJ WILL ALSO ACT TO INCREASE MOISTURE
CONTENT (3-4G/KG) TO AN APPROACHING COLD FRONT. THE WAVE ORIGINATES
WITH PACIFIC MOISTURE AND TRANSLATES ACROSS A CONTINENTAL AIRMASS
BEFORE BEING REINFORCED WITH GOM MOISTURE ON SUNDAY. TOUGH CALL ON
PRECIP TYPE WITH THIS SYSTEM AS TOP-DOWN IT FAVORS A COLD CANADIAN
TEMP PROFILE. SURFACE TO H7 HOWEVER...IT SEEMS THE WAA IS TAKING
OVER AND SURFACE TEMPS SHOULD BE AROUND +1C. WHILE THERE IS A CHANCE
THAT RAIN/SNOW MIX OR A 35F SNOW COULD OCCUR...FAVORING THE WARMER
SIDE OF GUIDANCE THAT INDICATES ABOVE FREEZING TEMPS IN THE BOUNDARY
LAYER (FIRST 1500+ FEET). FORECAST THEREFORE CALLING FOR A COLD 0.2
INCH RAIN EVENT SUNDAY AFTERNOON-EVENING.

BRIEF RIDGING ON MONDAY WILL ALLOW FOR DRY CONDITIONS TO PERSIST
ACROSS SOUTHEAST MICHIGAN FOR THE BEGINNING OF NEXT WEEK. ACTIVE
WEATHER QUICKLY RETURNS THOUGH ON MONDAY NIGHT AS A CLIPPER SYSTEM
ROLLS THROUGH THE REGION. TEMPERATURES LOOK TO BE COLD ENOUGH AT
THIS TIME TO SUPPORT ALL SNOW...WHICH COULD RESULT IN A HALF INCH OF
SNOW AT THE VERY LEAST...MAINLY NORTH OF THE M-59 CORRIDOR. THERE IS
STILL SOME DISAGREEMENT IN THE TRACK OF THIS SYSTEM THOUGH...SO
PRECIP TYPE AND AMOUNT IS NOT COMPLETELY CERTAIN. WARMER
TEMPERATURES AND DRY CONDITIONS RETURN ON WEDNESDAY AND LAST INTO
THURSDAY...WHEN THE NEXT POTENTIAL RAIN MAKER ARRIVES.

&&

.MARINE...

NORTH WINDS WILL BE SLOW TO RELAX OVER LAKE HURON TONIGHT AS ISOBARS
SPREAD OUT SOME DUE TO INCOMING HIGH PRESSURE. THE LAKE REMAINS
ACTIVE WITH UPPER LEVEL TEMPS STILL VERY COLD (H85 AT -13C)...WHICH
ADDS TO THE HIGHER WINDS OVER THE WATER. LOOK FOR HIGH WAVES
ESPECIALLY NEAR THE THUMB REGION AS THE NORTH FETCH IS FAVORABLE FOR
AMPLIFICATION. WINDS RAMP BACK UP SUNDAY WITH SOME GUSTS TO GALES AS
990MB LOW MOVES JUST NORTH OF THE REGION. SOUTHWEST WINDS WILL USHER
IN WARMER AIR...SO NOT EXPECTING LAKES TO BECOME UNSTABLE.

&&

.AVIATION...ISSUED 1226 PM EDT FRI MAR 27 2015

CLEARING TREND WILL ATTEMPT TO WORK IN FROM THE WEST/NORTHWEST AS
SUBSIDENCE OCCURS THIS AFTERNOON BEHIND UPPER LEVEL TROUGH AXIS. DO
THINK MBS WILL SCATTER OR CLEAR OUT. HOWEVER...COLD NORTHERLY FLOW
OFF LAKE HURON WILL TEND TO MAINTAIN LAKE CLOUDS AND EMBEDDED SNOW
SHOWERS FARTHER EAST. FORTUNATELY...CLOUD BASES AND VSBYS SHOULD BE
PREDOMINATELY OF THE LOW VFR VARIETY THROUGH TONIGHT...EVEN IF
CLOUDS DO IN FACT HOLD...WITH JUST LOCALIZED MVFR SNOW
SHOWERS/CEILINGS. SURFACE HIGH PRESSURE BUILDING INTO LOWER MICHIGAN
WILL ALLOW WINDS TO BACK A BIT TO THE NORTHWEST LATE TONIGHT...WHICH
SHOULD SET UP THE TAF SITES FOR MOSTLY CLEAR SKIES TOMORROW.

FOR DTW...LOW VFR CLOUDS AND BRIEF MVFR SNOW SHOWERS WILL DIMINISH
THIS AFTERNOON...WITH CONFIDENCE IN CLOUDS/CEILINGS HOLDING THEN
DIMINISHING THIS EVENING AND TONIGHT...AS DRIER AIR AND HIGH
PRESSURE ATTEMPTS TO BUILD IN FROM THE WEST.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CEILINGS AOB 5000 FT THIS AFTERNOON...MEDIUM
  CONFIDENCE THIS EVENING...LOW CONFIDENCE AFTER MIDNIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

SHORT TERM...SF
LONG TERM....MM/RK
MARINE.......MM
AVIATION.....SF


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




000
FXUS63 KDTX 271940
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
340 PM EDT FRI MAR 27 2015

.SHORT TERM...TONIGHT

GOOD SUBSIDENCE AND DRYING OCCURRING BEHIND UPPER LEVEL TROUGH AXIS
MOVING THROUGH THE CENTRAL GREAT LAKES THIS AFTERNOON...WITH SURFACE
DEW PTS PLUNGING TO AROUND ZERO OVER CENTRAL SECTIONS OF THE
STATE...UNDER MOSTLY CLEAR SKIES. CLOUDS HAVE THINNED OUT OVER
SOUTHEAST MICHIGAN...BUT COLD (NEGATIVE UPPER TEENS AT 850 MB)
NORTHERLY FLOW OFF LAKE HURON IS MAINTAINING JUST ENOUGH MOISTURE TO
MAINTAIN MOSTLY CLOUDY SKIES AND EMBEDDED SNOW SHOWERS. THE ACTIVITY
IS VERY DISORGANIZED...BUT STEEP LOW LEVEL LAPSE RATES HAVE PRODUCED
VERY SMALL INTENSE CELLS...DROPPING VSYBS BRIEFLY BELOW 1 MILE IN
ISOLATED SPOTS. WITH HIGH PRESSURE BUILDING OVER THE WESTERN GREAT
LAKES TONIGHT...THE DRIER AIR/CLEAR SKIES SHOULD CONTINUE TO BLEED
INTO SOUTHEAST MICHIGAN...BUT PROBABLY STRUGGLE TO ADVANCE MUCH PAST
U.S. 23. LONG FETCHED NORTHERLY FLOW AND LOW LEVEL CONVERGENCE
FORECASTED BY 12Z NAM OVER THUMB REGION THIS EVENING SHOULD
MAINTAIN...OR ALLOW FOR REDEVELOPMENT OF ACTIVITY. STILL...THE
OVERALL DRY ENVIRONMENT AND LOW INVERSION HEIGHTS WILL TEMPER
ACTIVITY...AND EXPECTING A VERY NARROW BAND WITH SOME MOVEMENT...AND
THUS ANTICIPATING ACCUMULATIONS BELOW 1 INCH.

WITH TEMPERATURES STILL HOLDING THE 20S THIS AFTERNOON...MINS IN THE
LOW TO MID TEENS SHOULD BE NO PROBLEM...WITH THE POTENTIAL FOR
SINGLE NUMBERS IF THAT CLEARING LINE ADVANCES EAST OVERNIGHT. RECORD
LOWS FOR MARCH 28TH ARE GENERALLY IN THE LOWER SINGLE NUMBERS AND
ARE LIKELY OUT OF REACH AS WINDS WILL PROBABLY NOT GO CALM EVEN IF
WE DO TOTALLY CLEAR OUT.

&&

.LONG TERM...

LONGWAVE TROUGH CURRENTLY CENTERED NEAR MICHIGAN AND INDIANA WILL
COMPACT AND MOVE EASTWARD...LEADING TO A 500MB HEIGHT RECOVERY
SUNDAY THROUGH THE EXTENDED PERIOD. SATURDAY WILL CONTINUE TO BE
WELL BELOW NORMAL AS THE H85 TEMP FIELD REMAINS IN THE NEGATIVE
TEENS C. EXPECTING MAXES IN THE MID 30S. DESPITE THESE LOW
VALUES...ANTICYCLONE DIRECTLY OVERHEAD WILL PROVIDE A LIGHT WIND
FIELD AND FULL SUN.  ADDING LATE MARCH INSOLATION...CONDITIONS MAY
NOT FEEL TOO BAD.

ONCE THE SURFACE HIGH MOVES SOUTHEAST OF THE CWA ON
SUNDAY...SOUTHWEST WINDS OF 40-50KT AT H85 WILL QUICKLY USHER IN
WARMER TEMPERATURES. THIS LLJ WILL ALSO ACT TO INCREASE MOISTURE
CONTENT (3-4G/KG) TO AN APPROACHING COLD FRONT. THE WAVE ORIGINATES
WITH PACIFIC MOISTURE AND TRANSLATES ACROSS A CONTINENTAL AIRMASS
BEFORE BEING REINFORCED WITH GOM MOISTURE ON SUNDAY. TOUGH CALL ON
PRECIP TYPE WITH THIS SYSTEM AS TOP-DOWN IT FAVORS A COLD CANADIAN
TEMP PROFILE. SURFACE TO H7 HOWEVER...IT SEEMS THE WAA IS TAKING
OVER AND SURFACE TEMPS SHOULD BE AROUND +1C. WHILE THERE IS A CHANCE
THAT RAIN/SNOW MIX OR A 35F SNOW COULD OCCUR...FAVORING THE WARMER
SIDE OF GUIDANCE THAT INDICATES ABOVE FREEZING TEMPS IN THE BOUNDARY
LAYER (FIRST 1500+ FEET). FORECAST THEREFORE CALLING FOR A COLD 0.2
INCH RAIN EVENT SUNDAY AFTERNOON-EVENING.

BRIEF RIDGING ON MONDAY WILL ALLOW FOR DRY CONDITIONS TO PERSIST
ACROSS SOUTHEAST MICHIGAN FOR THE BEGINNING OF NEXT WEEK. ACTIVE
WEATHER QUICKLY RETURNS THOUGH ON MONDAY NIGHT AS A CLIPPER SYSTEM
ROLLS THROUGH THE REGION. TEMPERATURES LOOK TO BE COLD ENOUGH AT
THIS TIME TO SUPPORT ALL SNOW...WHICH COULD RESULT IN A HALF INCH OF
SNOW AT THE VERY LEAST...MAINLY NORTH OF THE M-59 CORRIDOR. THERE IS
STILL SOME DISAGREEMENT IN THE TRACK OF THIS SYSTEM THOUGH...SO
PRECIP TYPE AND AMOUNT IS NOT COMPLETELY CERTAIN. WARMER
TEMPERATURES AND DRY CONDITIONS RETURN ON WEDNESDAY AND LAST INTO
THURSDAY...WHEN THE NEXT POTENTIAL RAIN MAKER ARRIVES.

&&

.MARINE...

NORTH WINDS WILL BE SLOW TO RELAX OVER LAKE HURON TONIGHT AS ISOBARS
SPREAD OUT SOME DUE TO INCOMING HIGH PRESSURE. THE LAKE REMAINS
ACTIVE WITH UPPER LEVEL TEMPS STILL VERY COLD (H85 AT -13C)...WHICH
ADDS TO THE HIGHER WINDS OVER THE WATER. LOOK FOR HIGH WAVES
ESPECIALLY NEAR THE THUMB REGION AS THE NORTH FETCH IS FAVORABLE FOR
AMPLIFICATION. WINDS RAMP BACK UP SUNDAY WITH SOME GUSTS TO GALES AS
990MB LOW MOVES JUST NORTH OF THE REGION. SOUTHWEST WINDS WILL USHER
IN WARMER AIR...SO NOT EXPECTING LAKES TO BECOME UNSTABLE.

&&

.AVIATION...ISSUED 1226 PM EDT FRI MAR 27 2015

CLEARING TREND WILL ATTEMPT TO WORK IN FROM THE WEST/NORTHWEST AS
SUBSIDENCE OCCURS THIS AFTERNOON BEHIND UPPER LEVEL TROUGH AXIS. DO
THINK MBS WILL SCATTER OR CLEAR OUT. HOWEVER...COLD NORTHERLY FLOW
OFF LAKE HURON WILL TEND TO MAINTAIN LAKE CLOUDS AND EMBEDDED SNOW
SHOWERS FARTHER EAST. FORTUNATELY...CLOUD BASES AND VSBYS SHOULD BE
PREDOMINATELY OF THE LOW VFR VARIETY THROUGH TONIGHT...EVEN IF
CLOUDS DO IN FACT HOLD...WITH JUST LOCALIZED MVFR SNOW
SHOWERS/CEILINGS. SURFACE HIGH PRESSURE BUILDING INTO LOWER MICHIGAN
WILL ALLOW WINDS TO BACK A BIT TO THE NORTHWEST LATE TONIGHT...WHICH
SHOULD SET UP THE TAF SITES FOR MOSTLY CLEAR SKIES TOMORROW.

FOR DTW...LOW VFR CLOUDS AND BRIEF MVFR SNOW SHOWERS WILL DIMINISH
THIS AFTERNOON...WITH CONFIDENCE IN CLOUDS/CEILINGS HOLDING THEN
DIMINISHING THIS EVENING AND TONIGHT...AS DRIER AIR AND HIGH
PRESSURE ATTEMPTS TO BUILD IN FROM THE WEST.

//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CEILINGS AOB 5000 FT THIS AFTERNOON...MEDIUM
  CONFIDENCE THIS EVENING...LOW CONFIDENCE AFTER MIDNIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

SHORT TERM...SF
LONG TERM....MM/RK
MARINE.......MM
AVIATION.....SF


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





000
FXUS63 KDTX 271626
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1226 PM EDT FRI MAR 27 2015

.AVIATION...

CLEARING TREND WILL ATTEMPT TO WORK IN FROM THE WEST/NORTHWEST AS
SUBSIDENCE OCCURS THIS AFTERNOON BEHIND UPPER LEVEL TROUGH AXIS. DO
THINK MBS WILL SCATTER OR CLEAR OUT. HOWEVER...COLD NORTHERLY FLOW
OFF LAKE HURON WILL TEND TO MAINTAIN LAKE CLOUDS AND EMBEDDED SNOW
SHOWERS FARTHER EAST. FORTUNATELY...CLOUD BASES AND VSBYS SHOULD BE
PREDOMINATELY OF THE LOW VFR VARIETY THROUGH TONIGHT...EVEN IF
CLOUDS DO IN FACT HOLD...WITH JUST LOCALIZED MVFR SNOW
SHOWERS/CEILINGS. SURFACE HIGH PRESSURE BUILDING INTO LOWER MICHIGAN
WILL ALLOW WINDS TO BACK A BIT TO THE NORTHWEST LATE TONIGHT...WHICH
SHOULD SET UP THE TAF SITES FOR MOSTLY CLEAR SKIES TOMORROW.

FOR DTW...LOW VFR CLOUDS AND BRIEF MVFR SNOW SHOWERS WILL DIMINISH
THIS AFTERNOON...WITH CONFIDENCE IN CLOUDS/CEILINGS HOLDING THEN
DIMINISHING THIS EVENING AND TONIGHT...AS DRIER AIR AND HIGH
PRESSURE ATTEMPTS TO BUILD IN FROM THE WEST.


//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CEILINGS AOB 5000 FT THIS AFTERNOON...MEDIUM
  CONFIDENCE THIS EVENING...LOW CONFIDENCE AFTER MIDNIGHT.

&&

.PREV DISCUSSION...ISSUED 911 AM EDT FRI MAR 27 2015

UPDATE...

12Z DTX SOUNDING INDICATED AN 850 MB TEMP OF -16 C...WITH APX
CHECKING IN AT -20 C. UPPER LEVEL TROUGH AXIS IS CURRENTLY MOVING
THROUGH THE CENTRAL GREAT LAKES. WATCHING SOUTHERN LAKE HURON SNOW
BAND(S) CLOSELY...AS EVEN KDTX RADAR PICKING UP THE SUBSTANTIAL ECHOS
(20-25 DBZ) AT THE 5500 FOOT LEVEL...WELL ABOVE THE STOUT
INVERSION INDICATED BY 12Z DTX SOUNDING...INDICATIVE OF THE LAKE
INFLUENCE. NAM/RAP13 STILL INDICTING THIS BAND WILL PUSH
SOUTH/SOUTHWEST THROUGH THE DAY BASED ON 925 MB OMEGA/CONVERGENCE
FIELDS...AND HOPEFULLY THE TRANSIENT NATURE WILL KEEP THE
LOCALIZED ACCUMULATIONS TO A COUPLE INCHES AROUND PORT HURON AREA.
FURTHER/INCREASING BOUNDARY LAYER MIXING/SUBSIDENCE BEHIND THE
UPPER LEVEL TROUGH AXIS THIS AFTERNOON AND BAND MOVING AWAY FROM
MOISTURE SOURCE SHOULD FURTHER DISRUPT THE ACTIVITY...HELPING TO
LIMIT THE ACCUMULATIONS FARTHER SOUTH. QUICK LOOK AT THE 12Z NAM
SHOWS ANOTHER LAKE BAND DEVELOPING OVER THE THUMB REGION THIS
EVENING WITH THE GOOD NORTHERLY FETCH OFF LAKE HURON...BUT
INVERSION HEIGHTS SLIGHTLY LOWER AND ADDITIONAL DRY AIR MAY LIMIT
ACCUMULATIONS TO INCH OR LESS...UNLIKE THE TWO INCHES SEEN IN
ELKTON THIS MORNING.

PREV DISCUSSION...ISSUED 410 AM EDT FRI MAR 27 2015

SHORT TERM...TODAY AND TONIGHT

A FULL LATITUDE TROUGH OVER THE EASTERN CONTINENTAL UNITED STATES
WILL LEAD TO RAW CONDITIONS OVER SOUTHEASTERN MICHIGAN TODAY. THE
SPINE OF THE COLD AIR IS FORECASTED TO SETTLE INTO EASTERN LOWER
MICHIGAN BY 21Z THIS AFTERNOON. 850MB AND 925MB TEMPERATURES ARE
FORECASTED TO BE SOLIDLY OUTSIDE OF 1 SIGMA.  A STRAIGHT MIXING
TECHNIQUE SUPPORTS READINGS LIMITING OUT IN THE 20S. THE OUTGOING
FORECAST WILL SHADE A DEGREE OR TWO WARMER THAN THE AVAILABLE RAW
MODEL OUTPUT...MIDDLE 20S IN THE THUMB TO NEAR THE FREEZING MARK
ACROSS THE SOUTH...APPROXIMATELY 20 DEGREES BELOW NORMAL. A
SHARP...NORTH WIND WILL LEAD TO WINDCHILLS IN THE TEENS TO LOWER 20S
TODAY...AND IN THE LOWER SINGLE DIGITS TONIGHT.

WILL BE WATCHING A NUMBER OF THINGS FOR MORE ORGANIZED SNOW SHOWER
ACTIVITY TODAY. THE FIRST WILL BE ALONG A SURFACE CONVERGENCE
BOUNDARY ASSOCIATED WITH A WEST TO EAST SURFACE TROUGH AXIS THAT IS
FORECASTED TO PUSH SOUTHWARD THROUGH SOUTHEASTERN MICHIGAN DURING
THE COURSE OF THE ENTIRE DAY. RECENT RADAR IMAGERY FROM EXETER
ONTARIO SUGGESTS A FAIR AMOUNT OF REFLECTORS IN THE GENERAL LOCATION
OF THE AXIS THIS MORNING. HOWEVER...OVERSHOOTING OF THE RADAR BEAM
AT THESE DISTANCES LEADS TO A HIGH AMOUNT UNCERTAINTY. THE INHERITED
FORECAST STILL REMAINS VALID CALLING FOR SNOW SHOWERS
LIKELY/NUMEROUS IN THE THUMB THIS MORNING. AFTER THE MID TO LATE
MORNING ...FORECASTED LAPSE RATES SUPPORT A FLARE UP OF ACTIVITY
DUE TO THE DEEPENING OF THE BOUNDARY LAYER FROM DAYTIME HEATING.
PLAN VIEW EVOLUTION OF LL THETA E LAPSE RATES ALONG HIRES MODEL
OUTPUT SUGGESTS THIS POTENTIAL IS FOR ALL OF SOUTHEASTERN
MICHIGAN. THIS THERMODYNAMIC SUPPORT IS IN ADDITION TO A
CONTRACTION IN THE WAVELENGTH OF THE UPPER LEVEL TROUGH.
CONCENTRATED DCVA IN COMBINATION WITH THE LOCALIZED
CONVERGENCE/NEAR SURFACE TROUGH AXIS WILL LEAD TO ENOUGH FORCING
TO SUPPORT LIGHT SNOW SHOWER ACTIVITY ACROSS MUCH OF THE AREA THIS
AFTERNOON. THE SUPERSATURATION WRT ICE SIGNAL IS GOOD ALONG WITH
THE STEEP LAPSE RATE POCKET ENCAPSULATING THE -15C ISOTHERM. A
LIGHT DUSTING...TO MINOR ACCUMULATIONS OF GENERALLY LESS THAN ONE
INCH WILL BE POSSIBLE FOR MUCH OF THE CWA TODAY. IT REMAINS
POSSIBLE FOR SNOWFALL ACCUMULATIONS OF AN INCH OR GREATER FOR THE
THUMB REGION.

LONG TERM...

CONTINUED DEEP NORTHERLY FLOW WILL START SATURDAY BEFORE THE LARGE
AREA OF COLD HIGH PRESSURE BECOMES CENTERED OVER LOWER MICHIGAN
DURING THE REST OF THE DAY. THE WIND DIRECTION FROM LAKE HURON INTO
THE THUMB WILL FAVOR LINGERING BUT DIMINISHING LAKE EFFECT
POTENTIAL. MODEL SOUNDINGS INDICATE NEAR DRY ADIABATIC LAPSE RATES
BUT ALSO SHOW CONVECTIVE DEPTH FORCED QUICKLY BELOW 850 MB/5000 FT.
THIS MAY BE GOOD FOR SOME FLURRIES BUT MORE LIKELY JUST SOME
STRATOCU WITHIN A SHALLOW LAYER OF SATURATION NEAR -15C THAT MIXES
OUT BY AFTERNOON. THE BUILDING SURFACE HIGH AND BACKING LOW LEVEL
WIND FIELD WILL NUDGE THE LOW LEVEL THERMAL TROUGH EASTWARD DURING
THE AFTERNOON. THIS...COMBINED WITH FULL LATE MARCH SUN...WILL HELP
MAX TEMPS RISE TOWARD THE MID 30S...BUT STILL A SOLID 15 DEGREES
BELOW NORMAL. THE STAGE WILL THEN BE SET FOR A COLD SATURDAY NIGHT
WITH MIN TEMPS LIKELY OCCURRING AROUND MIDNIGHT BEFORE HIGH CLOUDS
THICKEN AND SOUTHWEST WIND INCREASES OVERNIGHT THROUGH SUNRISE
SUNDAY.

THE HIGH CLOUDS SATURDAY NIGHT WILL BE THE FIRST SIGN OF THE NEXT
LOW PRESSURE SYSTEM ARRIVING IN THE GREAT LAKES. THIS SYSTEM IS
STILL OFFSHORE OVER THE GULF OF ALASKA AND WILL BE MOVING INLAND
TONIGHT BEFORE POWERING THROUGH THE LONG WAVE RIDGE OVER THE ROCKIES
DURING SATURDAY. THERE IS IMPROVED AGREEMENT IN THE 00Z MODEL RUNS
WITH RESPECT TO TIMING THE ARRIVAL OF PRECIPITATION WITH THIS SYSTEM
SUNDAY AFTERNOON IN SE MICHIGAN. THE MOISTURE PROFILE WILL BE A
HYBRID OF MID LEVEL PACIFIC AND LOW LEVEL GULF MODIFIED CONTINENTAL
WHICH IS SEEMS ADEQUATE FOR THE 0.1-0.2 MODEL QPF AND LIKELY POPS
SUNDAY AFTERNOON AND EVENING. THERE WILL BE SOME WET BULB COOLING
POTENTIAL AT ONSET BUT THE NAM IS GIVING IT TOO MUCH CREDIT FOR
COOLING THE BOUNDARY LAYER ENOUGH FOR SNOW IN THE MIDDLE OF THE DAY.
A PROFILE MORE LIKE THE GFS IS PREFERRED AND HELPS RULE OUT A
RAIN/SNOW MIX UNTIL SUNDAY NIGHT WHEN COLDER AIR SPILLS BACK INTO
THE REGION BEHIND THE SYSTEM.

GLOBAL MODELS MAINTAIN THE FRONTAL ZONE NEARBY TO START NEXT WEEK
WITH A COUPLE MORE LOW PREDICTABILITY SHORT WAVES TRAVERSING THE NW
FLOW ALOFT. EXPECT COLD AIR INTRUSIONS TO BE LESS HARSH COMPARED TO
THIS WEEKEND. AT THIS POINT...A STRONGER LOW PRESSURE SYSTEM IS
PROJECTED AROUND THE WEDNESDAY PERIOD THAT HAS POTENTIAL TO ALTER
THE LARGE SCALE PATTERN ENOUGH TO LIFT TEMPERATURES BACK TO NORMAL
FOR THE SECOND HALF OF NEXT WEEK.

MARINE...

STRONG NORTH WIND OVER LAKE HURON AND LOWER MICHIGAN WILL CARRY AIR
COLD ENOUGH FOR SNOW SHOWERS TODAY AND TONIGHT. GUSTS NEAR 30 KNOTS
WILL THEN EASE BACK DURING SATURDAY AS HIGH PRESSURE SETTLES
OVERHEAD. SOUTHWEST WIND WILL THEN RAMP UP SATURDAY NIGHT INTO
SUNDAY AS THE NEXT LOW PRESSURE SYSTEM MOVES INTO THE MIDWEST AND
WESTERN GREAT LAKES. SOUTHWEST GUSTS AROUND 25 KNOTS WILL BRING BACK
ENOUGH WARM AIR FOR MOSTLY RAIN SUNDAY AFTERNOON AND EVENING. COLDER
AIR WILL RETURN MONDAY BUT NOT AS COLD AS THIS WEEKEND.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....SF
UPDATE.......SF
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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




000
FXUS63 KDTX 271626
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1226 PM EDT FRI MAR 27 2015

.AVIATION...

CLEARING TREND WILL ATTEMPT TO WORK IN FROM THE WEST/NORTHWEST AS
SUBSIDENCE OCCURS THIS AFTERNOON BEHIND UPPER LEVEL TROUGH AXIS. DO
THINK MBS WILL SCATTER OR CLEAR OUT. HOWEVER...COLD NORTHERLY FLOW
OFF LAKE HURON WILL TEND TO MAINTAIN LAKE CLOUDS AND EMBEDDED SNOW
SHOWERS FARTHER EAST. FORTUNATELY...CLOUD BASES AND VSBYS SHOULD BE
PREDOMINATELY OF THE LOW VFR VARIETY THROUGH TONIGHT...EVEN IF
CLOUDS DO IN FACT HOLD...WITH JUST LOCALIZED MVFR SNOW
SHOWERS/CEILINGS. SURFACE HIGH PRESSURE BUILDING INTO LOWER MICHIGAN
WILL ALLOW WINDS TO BACK A BIT TO THE NORTHWEST LATE TONIGHT...WHICH
SHOULD SET UP THE TAF SITES FOR MOSTLY CLEAR SKIES TOMORROW.

FOR DTW...LOW VFR CLOUDS AND BRIEF MVFR SNOW SHOWERS WILL DIMINISH
THIS AFTERNOON...WITH CONFIDENCE IN CLOUDS/CEILINGS HOLDING THEN
DIMINISHING THIS EVENING AND TONIGHT...AS DRIER AIR AND HIGH
PRESSURE ATTEMPTS TO BUILD IN FROM THE WEST.


//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CEILINGS AOB 5000 FT THIS AFTERNOON...MEDIUM
  CONFIDENCE THIS EVENING...LOW CONFIDENCE AFTER MIDNIGHT.

&&

.PREV DISCUSSION...ISSUED 911 AM EDT FRI MAR 27 2015

UPDATE...

12Z DTX SOUNDING INDICATED AN 850 MB TEMP OF -16 C...WITH APX
CHECKING IN AT -20 C. UPPER LEVEL TROUGH AXIS IS CURRENTLY MOVING
THROUGH THE CENTRAL GREAT LAKES. WATCHING SOUTHERN LAKE HURON SNOW
BAND(S) CLOSELY...AS EVEN KDTX RADAR PICKING UP THE SUBSTANTIAL ECHOS
(20-25 DBZ) AT THE 5500 FOOT LEVEL...WELL ABOVE THE STOUT
INVERSION INDICATED BY 12Z DTX SOUNDING...INDICATIVE OF THE LAKE
INFLUENCE. NAM/RAP13 STILL INDICTING THIS BAND WILL PUSH
SOUTH/SOUTHWEST THROUGH THE DAY BASED ON 925 MB OMEGA/CONVERGENCE
FIELDS...AND HOPEFULLY THE TRANSIENT NATURE WILL KEEP THE
LOCALIZED ACCUMULATIONS TO A COUPLE INCHES AROUND PORT HURON AREA.
FURTHER/INCREASING BOUNDARY LAYER MIXING/SUBSIDENCE BEHIND THE
UPPER LEVEL TROUGH AXIS THIS AFTERNOON AND BAND MOVING AWAY FROM
MOISTURE SOURCE SHOULD FURTHER DISRUPT THE ACTIVITY...HELPING TO
LIMIT THE ACCUMULATIONS FARTHER SOUTH. QUICK LOOK AT THE 12Z NAM
SHOWS ANOTHER LAKE BAND DEVELOPING OVER THE THUMB REGION THIS
EVENING WITH THE GOOD NORTHERLY FETCH OFF LAKE HURON...BUT
INVERSION HEIGHTS SLIGHTLY LOWER AND ADDITIONAL DRY AIR MAY LIMIT
ACCUMULATIONS TO INCH OR LESS...UNLIKE THE TWO INCHES SEEN IN
ELKTON THIS MORNING.

PREV DISCUSSION...ISSUED 410 AM EDT FRI MAR 27 2015

SHORT TERM...TODAY AND TONIGHT

A FULL LATITUDE TROUGH OVER THE EASTERN CONTINENTAL UNITED STATES
WILL LEAD TO RAW CONDITIONS OVER SOUTHEASTERN MICHIGAN TODAY. THE
SPINE OF THE COLD AIR IS FORECASTED TO SETTLE INTO EASTERN LOWER
MICHIGAN BY 21Z THIS AFTERNOON. 850MB AND 925MB TEMPERATURES ARE
FORECASTED TO BE SOLIDLY OUTSIDE OF 1 SIGMA.  A STRAIGHT MIXING
TECHNIQUE SUPPORTS READINGS LIMITING OUT IN THE 20S. THE OUTGOING
FORECAST WILL SHADE A DEGREE OR TWO WARMER THAN THE AVAILABLE RAW
MODEL OUTPUT...MIDDLE 20S IN THE THUMB TO NEAR THE FREEZING MARK
ACROSS THE SOUTH...APPROXIMATELY 20 DEGREES BELOW NORMAL. A
SHARP...NORTH WIND WILL LEAD TO WINDCHILLS IN THE TEENS TO LOWER 20S
TODAY...AND IN THE LOWER SINGLE DIGITS TONIGHT.

WILL BE WATCHING A NUMBER OF THINGS FOR MORE ORGANIZED SNOW SHOWER
ACTIVITY TODAY. THE FIRST WILL BE ALONG A SURFACE CONVERGENCE
BOUNDARY ASSOCIATED WITH A WEST TO EAST SURFACE TROUGH AXIS THAT IS
FORECASTED TO PUSH SOUTHWARD THROUGH SOUTHEASTERN MICHIGAN DURING
THE COURSE OF THE ENTIRE DAY. RECENT RADAR IMAGERY FROM EXETER
ONTARIO SUGGESTS A FAIR AMOUNT OF REFLECTORS IN THE GENERAL LOCATION
OF THE AXIS THIS MORNING. HOWEVER...OVERSHOOTING OF THE RADAR BEAM
AT THESE DISTANCES LEADS TO A HIGH AMOUNT UNCERTAINTY. THE INHERITED
FORECAST STILL REMAINS VALID CALLING FOR SNOW SHOWERS
LIKELY/NUMEROUS IN THE THUMB THIS MORNING. AFTER THE MID TO LATE
MORNING ...FORECASTED LAPSE RATES SUPPORT A FLARE UP OF ACTIVITY
DUE TO THE DEEPENING OF THE BOUNDARY LAYER FROM DAYTIME HEATING.
PLAN VIEW EVOLUTION OF LL THETA E LAPSE RATES ALONG HIRES MODEL
OUTPUT SUGGESTS THIS POTENTIAL IS FOR ALL OF SOUTHEASTERN
MICHIGAN. THIS THERMODYNAMIC SUPPORT IS IN ADDITION TO A
CONTRACTION IN THE WAVELENGTH OF THE UPPER LEVEL TROUGH.
CONCENTRATED DCVA IN COMBINATION WITH THE LOCALIZED
CONVERGENCE/NEAR SURFACE TROUGH AXIS WILL LEAD TO ENOUGH FORCING
TO SUPPORT LIGHT SNOW SHOWER ACTIVITY ACROSS MUCH OF THE AREA THIS
AFTERNOON. THE SUPERSATURATION WRT ICE SIGNAL IS GOOD ALONG WITH
THE STEEP LAPSE RATE POCKET ENCAPSULATING THE -15C ISOTHERM. A
LIGHT DUSTING...TO MINOR ACCUMULATIONS OF GENERALLY LESS THAN ONE
INCH WILL BE POSSIBLE FOR MUCH OF THE CWA TODAY. IT REMAINS
POSSIBLE FOR SNOWFALL ACCUMULATIONS OF AN INCH OR GREATER FOR THE
THUMB REGION.

LONG TERM...

CONTINUED DEEP NORTHERLY FLOW WILL START SATURDAY BEFORE THE LARGE
AREA OF COLD HIGH PRESSURE BECOMES CENTERED OVER LOWER MICHIGAN
DURING THE REST OF THE DAY. THE WIND DIRECTION FROM LAKE HURON INTO
THE THUMB WILL FAVOR LINGERING BUT DIMINISHING LAKE EFFECT
POTENTIAL. MODEL SOUNDINGS INDICATE NEAR DRY ADIABATIC LAPSE RATES
BUT ALSO SHOW CONVECTIVE DEPTH FORCED QUICKLY BELOW 850 MB/5000 FT.
THIS MAY BE GOOD FOR SOME FLURRIES BUT MORE LIKELY JUST SOME
STRATOCU WITHIN A SHALLOW LAYER OF SATURATION NEAR -15C THAT MIXES
OUT BY AFTERNOON. THE BUILDING SURFACE HIGH AND BACKING LOW LEVEL
WIND FIELD WILL NUDGE THE LOW LEVEL THERMAL TROUGH EASTWARD DURING
THE AFTERNOON. THIS...COMBINED WITH FULL LATE MARCH SUN...WILL HELP
MAX TEMPS RISE TOWARD THE MID 30S...BUT STILL A SOLID 15 DEGREES
BELOW NORMAL. THE STAGE WILL THEN BE SET FOR A COLD SATURDAY NIGHT
WITH MIN TEMPS LIKELY OCCURRING AROUND MIDNIGHT BEFORE HIGH CLOUDS
THICKEN AND SOUTHWEST WIND INCREASES OVERNIGHT THROUGH SUNRISE
SUNDAY.

THE HIGH CLOUDS SATURDAY NIGHT WILL BE THE FIRST SIGN OF THE NEXT
LOW PRESSURE SYSTEM ARRIVING IN THE GREAT LAKES. THIS SYSTEM IS
STILL OFFSHORE OVER THE GULF OF ALASKA AND WILL BE MOVING INLAND
TONIGHT BEFORE POWERING THROUGH THE LONG WAVE RIDGE OVER THE ROCKIES
DURING SATURDAY. THERE IS IMPROVED AGREEMENT IN THE 00Z MODEL RUNS
WITH RESPECT TO TIMING THE ARRIVAL OF PRECIPITATION WITH THIS SYSTEM
SUNDAY AFTERNOON IN SE MICHIGAN. THE MOISTURE PROFILE WILL BE A
HYBRID OF MID LEVEL PACIFIC AND LOW LEVEL GULF MODIFIED CONTINENTAL
WHICH IS SEEMS ADEQUATE FOR THE 0.1-0.2 MODEL QPF AND LIKELY POPS
SUNDAY AFTERNOON AND EVENING. THERE WILL BE SOME WET BULB COOLING
POTENTIAL AT ONSET BUT THE NAM IS GIVING IT TOO MUCH CREDIT FOR
COOLING THE BOUNDARY LAYER ENOUGH FOR SNOW IN THE MIDDLE OF THE DAY.
A PROFILE MORE LIKE THE GFS IS PREFERRED AND HELPS RULE OUT A
RAIN/SNOW MIX UNTIL SUNDAY NIGHT WHEN COLDER AIR SPILLS BACK INTO
THE REGION BEHIND THE SYSTEM.

GLOBAL MODELS MAINTAIN THE FRONTAL ZONE NEARBY TO START NEXT WEEK
WITH A COUPLE MORE LOW PREDICTABILITY SHORT WAVES TRAVERSING THE NW
FLOW ALOFT. EXPECT COLD AIR INTRUSIONS TO BE LESS HARSH COMPARED TO
THIS WEEKEND. AT THIS POINT...A STRONGER LOW PRESSURE SYSTEM IS
PROJECTED AROUND THE WEDNESDAY PERIOD THAT HAS POTENTIAL TO ALTER
THE LARGE SCALE PATTERN ENOUGH TO LIFT TEMPERATURES BACK TO NORMAL
FOR THE SECOND HALF OF NEXT WEEK.

MARINE...

STRONG NORTH WIND OVER LAKE HURON AND LOWER MICHIGAN WILL CARRY AIR
COLD ENOUGH FOR SNOW SHOWERS TODAY AND TONIGHT. GUSTS NEAR 30 KNOTS
WILL THEN EASE BACK DURING SATURDAY AS HIGH PRESSURE SETTLES
OVERHEAD. SOUTHWEST WIND WILL THEN RAMP UP SATURDAY NIGHT INTO
SUNDAY AS THE NEXT LOW PRESSURE SYSTEM MOVES INTO THE MIDWEST AND
WESTERN GREAT LAKES. SOUTHWEST GUSTS AROUND 25 KNOTS WILL BRING BACK
ENOUGH WARM AIR FOR MOSTLY RAIN SUNDAY AFTERNOON AND EVENING. COLDER
AIR WILL RETURN MONDAY BUT NOT AS COLD AS THIS WEEKEND.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....SF
UPDATE.......SF
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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




000
FXUS63 KDTX 271626
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1226 PM EDT FRI MAR 27 2015

.AVIATION...

CLEARING TREND WILL ATTEMPT TO WORK IN FROM THE WEST/NORTHWEST AS
SUBSIDENCE OCCURS THIS AFTERNOON BEHIND UPPER LEVEL TROUGH AXIS. DO
THINK MBS WILL SCATTER OR CLEAR OUT. HOWEVER...COLD NORTHERLY FLOW
OFF LAKE HURON WILL TEND TO MAINTAIN LAKE CLOUDS AND EMBEDDED SNOW
SHOWERS FARTHER EAST. FORTUNATELY...CLOUD BASES AND VSBYS SHOULD BE
PREDOMINATELY OF THE LOW VFR VARIETY THROUGH TONIGHT...EVEN IF
CLOUDS DO IN FACT HOLD...WITH JUST LOCALIZED MVFR SNOW
SHOWERS/CEILINGS. SURFACE HIGH PRESSURE BUILDING INTO LOWER MICHIGAN
WILL ALLOW WINDS TO BACK A BIT TO THE NORTHWEST LATE TONIGHT...WHICH
SHOULD SET UP THE TAF SITES FOR MOSTLY CLEAR SKIES TOMORROW.

FOR DTW...LOW VFR CLOUDS AND BRIEF MVFR SNOW SHOWERS WILL DIMINISH
THIS AFTERNOON...WITH CONFIDENCE IN CLOUDS/CEILINGS HOLDING THEN
DIMINISHING THIS EVENING AND TONIGHT...AS DRIER AIR AND HIGH
PRESSURE ATTEMPTS TO BUILD IN FROM THE WEST.


//DTW THRESHOLD PROBABILITIES...

* HIGH CONFIDENCE IN CEILINGS AOB 5000 FT THIS AFTERNOON...MEDIUM
  CONFIDENCE THIS EVENING...LOW CONFIDENCE AFTER MIDNIGHT.

&&

.PREV DISCUSSION...ISSUED 911 AM EDT FRI MAR 27 2015

UPDATE...

12Z DTX SOUNDING INDICATED AN 850 MB TEMP OF -16 C...WITH APX
CHECKING IN AT -20 C. UPPER LEVEL TROUGH AXIS IS CURRENTLY MOVING
THROUGH THE CENTRAL GREAT LAKES. WATCHING SOUTHERN LAKE HURON SNOW
BAND(S) CLOSELY...AS EVEN KDTX RADAR PICKING UP THE SUBSTANTIAL ECHOS
(20-25 DBZ) AT THE 5500 FOOT LEVEL...WELL ABOVE THE STOUT
INVERSION INDICATED BY 12Z DTX SOUNDING...INDICATIVE OF THE LAKE
INFLUENCE. NAM/RAP13 STILL INDICTING THIS BAND WILL PUSH
SOUTH/SOUTHWEST THROUGH THE DAY BASED ON 925 MB OMEGA/CONVERGENCE
FIELDS...AND HOPEFULLY THE TRANSIENT NATURE WILL KEEP THE
LOCALIZED ACCUMULATIONS TO A COUPLE INCHES AROUND PORT HURON AREA.
FURTHER/INCREASING BOUNDARY LAYER MIXING/SUBSIDENCE BEHIND THE
UPPER LEVEL TROUGH AXIS THIS AFTERNOON AND BAND MOVING AWAY FROM
MOISTURE SOURCE SHOULD FURTHER DISRUPT THE ACTIVITY...HELPING TO
LIMIT THE ACCUMULATIONS FARTHER SOUTH. QUICK LOOK AT THE 12Z NAM
SHOWS ANOTHER LAKE BAND DEVELOPING OVER THE THUMB REGION THIS
EVENING WITH THE GOOD NORTHERLY FETCH OFF LAKE HURON...BUT
INVERSION HEIGHTS SLIGHTLY LOWER AND ADDITIONAL DRY AIR MAY LIMIT
ACCUMULATIONS TO INCH OR LESS...UNLIKE THE TWO INCHES SEEN IN
ELKTON THIS MORNING.

PREV DISCUSSION...ISSUED 410 AM EDT FRI MAR 27 2015

SHORT TERM...TODAY AND TONIGHT

A FULL LATITUDE TROUGH OVER THE EASTERN CONTINENTAL UNITED STATES
WILL LEAD TO RAW CONDITIONS OVER SOUTHEASTERN MICHIGAN TODAY. THE
SPINE OF THE COLD AIR IS FORECASTED TO SETTLE INTO EASTERN LOWER
MICHIGAN BY 21Z THIS AFTERNOON. 850MB AND 925MB TEMPERATURES ARE
FORECASTED TO BE SOLIDLY OUTSIDE OF 1 SIGMA.  A STRAIGHT MIXING
TECHNIQUE SUPPORTS READINGS LIMITING OUT IN THE 20S. THE OUTGOING
FORECAST WILL SHADE A DEGREE OR TWO WARMER THAN THE AVAILABLE RAW
MODEL OUTPUT...MIDDLE 20S IN THE THUMB TO NEAR THE FREEZING MARK
ACROSS THE SOUTH...APPROXIMATELY 20 DEGREES BELOW NORMAL. A
SHARP...NORTH WIND WILL LEAD TO WINDCHILLS IN THE TEENS TO LOWER 20S
TODAY...AND IN THE LOWER SINGLE DIGITS TONIGHT.

WILL BE WATCHING A NUMBER OF THINGS FOR MORE ORGANIZED SNOW SHOWER
ACTIVITY TODAY. THE FIRST WILL BE ALONG A SURFACE CONVERGENCE
BOUNDARY ASSOCIATED WITH A WEST TO EAST SURFACE TROUGH AXIS THAT IS
FORECASTED TO PUSH SOUTHWARD THROUGH SOUTHEASTERN MICHIGAN DURING
THE COURSE OF THE ENTIRE DAY. RECENT RADAR IMAGERY FROM EXETER
ONTARIO SUGGESTS A FAIR AMOUNT OF REFLECTORS IN THE GENERAL LOCATION
OF THE AXIS THIS MORNING. HOWEVER...OVERSHOOTING OF THE RADAR BEAM
AT THESE DISTANCES LEADS TO A HIGH AMOUNT UNCERTAINTY. THE INHERITED
FORECAST STILL REMAINS VALID CALLING FOR SNOW SHOWERS
LIKELY/NUMEROUS IN THE THUMB THIS MORNING. AFTER THE MID TO LATE
MORNING ...FORECASTED LAPSE RATES SUPPORT A FLARE UP OF ACTIVITY
DUE TO THE DEEPENING OF THE BOUNDARY LAYER FROM DAYTIME HEATING.
PLAN VIEW EVOLUTION OF LL THETA E LAPSE RATES ALONG HIRES MODEL
OUTPUT SUGGESTS THIS POTENTIAL IS FOR ALL OF SOUTHEASTERN
MICHIGAN. THIS THERMODYNAMIC SUPPORT IS IN ADDITION TO A
CONTRACTION IN THE WAVELENGTH OF THE UPPER LEVEL TROUGH.
CONCENTRATED DCVA IN COMBINATION WITH THE LOCALIZED
CONVERGENCE/NEAR SURFACE TROUGH AXIS WILL LEAD TO ENOUGH FORCING
TO SUPPORT LIGHT SNOW SHOWER ACTIVITY ACROSS MUCH OF THE AREA THIS
AFTERNOON. THE SUPERSATURATION WRT ICE SIGNAL IS GOOD ALONG WITH
THE STEEP LAPSE RATE POCKET ENCAPSULATING THE -15C ISOTHERM. A
LIGHT DUSTING...TO MINOR ACCUMULATIONS OF GENERALLY LESS THAN ONE
INCH WILL BE POSSIBLE FOR MUCH OF THE CWA TODAY. IT REMAINS
POSSIBLE FOR SNOWFALL ACCUMULATIONS OF AN INCH OR GREATER FOR THE
THUMB REGION.

LONG TERM...

CONTINUED DEEP NORTHERLY FLOW WILL START SATURDAY BEFORE THE LARGE
AREA OF COLD HIGH PRESSURE BECOMES CENTERED OVER LOWER MICHIGAN
DURING THE REST OF THE DAY. THE WIND DIRECTION FROM LAKE HURON INTO
THE THUMB WILL FAVOR LINGERING BUT DIMINISHING LAKE EFFECT
POTENTIAL. MODEL SOUNDINGS INDICATE NEAR DRY ADIABATIC LAPSE RATES
BUT ALSO SHOW CONVECTIVE DEPTH FORCED QUICKLY BELOW 850 MB/5000 FT.
THIS MAY BE GOOD FOR SOME FLURRIES BUT MORE LIKELY JUST SOME
STRATOCU WITHIN A SHALLOW LAYER OF SATURATION NEAR -15C THAT MIXES
OUT BY AFTERNOON. THE BUILDING SURFACE HIGH AND BACKING LOW LEVEL
WIND FIELD WILL NUDGE THE LOW LEVEL THERMAL TROUGH EASTWARD DURING
THE AFTERNOON. THIS...COMBINED WITH FULL LATE MARCH SUN...WILL HELP
MAX TEMPS RISE TOWARD THE MID 30S...BUT STILL A SOLID 15 DEGREES
BELOW NORMAL. THE STAGE WILL THEN BE SET FOR A COLD SATURDAY NIGHT
WITH MIN TEMPS LIKELY OCCURRING AROUND MIDNIGHT BEFORE HIGH CLOUDS
THICKEN AND SOUTHWEST WIND INCREASES OVERNIGHT THROUGH SUNRISE
SUNDAY.

THE HIGH CLOUDS SATURDAY NIGHT WILL BE THE FIRST SIGN OF THE NEXT
LOW PRESSURE SYSTEM ARRIVING IN THE GREAT LAKES. THIS SYSTEM IS
STILL OFFSHORE OVER THE GULF OF ALASKA AND WILL BE MOVING INLAND
TONIGHT BEFORE POWERING THROUGH THE LONG WAVE RIDGE OVER THE ROCKIES
DURING SATURDAY. THERE IS IMPROVED AGREEMENT IN THE 00Z MODEL RUNS
WITH RESPECT TO TIMING THE ARRIVAL OF PRECIPITATION WITH THIS SYSTEM
SUNDAY AFTERNOON IN SE MICHIGAN. THE MOISTURE PROFILE WILL BE A
HYBRID OF MID LEVEL PACIFIC AND LOW LEVEL GULF MODIFIED CONTINENTAL
WHICH IS SEEMS ADEQUATE FOR THE 0.1-0.2 MODEL QPF AND LIKELY POPS
SUNDAY AFTERNOON AND EVENING. THERE WILL BE SOME WET BULB COOLING
POTENTIAL AT ONSET BUT THE NAM IS GIVING IT TOO MUCH CREDIT FOR
COOLING THE BOUNDARY LAYER ENOUGH FOR SNOW IN THE MIDDLE OF THE DAY.
A PROFILE MORE LIKE THE GFS IS PREFERRED AND HELPS RULE OUT A
RAIN/SNOW MIX UNTIL SUNDAY NIGHT WHEN COLDER AIR SPILLS BACK INTO
THE REGION BEHIND THE SYSTEM.

GLOBAL MODELS MAINTAIN THE FRONTAL ZONE NEARBY TO START NEXT WEEK
WITH A COUPLE MORE LOW PREDICTABILITY SHORT WAVES TRAVERSING THE NW
FLOW ALOFT. EXPECT COLD AIR INTRUSIONS TO BE LESS HARSH COMPARED TO
THIS WEEKEND. AT THIS POINT...A STRONGER LOW PRESSURE SYSTEM IS
PROJECTED AROUND THE WEDNESDAY PERIOD THAT HAS POTENTIAL TO ALTER
THE LARGE SCALE PATTERN ENOUGH TO LIFT TEMPERATURES BACK TO NORMAL
FOR THE SECOND HALF OF NEXT WEEK.

MARINE...

STRONG NORTH WIND OVER LAKE HURON AND LOWER MICHIGAN WILL CARRY AIR
COLD ENOUGH FOR SNOW SHOWERS TODAY AND TONIGHT. GUSTS NEAR 30 KNOTS
WILL THEN EASE BACK DURING SATURDAY AS HIGH PRESSURE SETTLES
OVERHEAD. SOUTHWEST WIND WILL THEN RAMP UP SATURDAY NIGHT INTO
SUNDAY AS THE NEXT LOW PRESSURE SYSTEM MOVES INTO THE MIDWEST AND
WESTERN GREAT LAKES. SOUTHWEST GUSTS AROUND 25 KNOTS WILL BRING BACK
ENOUGH WARM AIR FOR MOSTLY RAIN SUNDAY AFTERNOON AND EVENING. COLDER
AIR WILL RETURN MONDAY BUT NOT AS COLD AS THIS WEEKEND.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....SF
UPDATE.......SF
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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





000
FXUS63 KDTX 271311
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
911 AM EDT FRI MAR 27 2015

.UPDATE...

12Z DTX SOUNDING INDICATED AN 850 MB TEMP OF -16 C...WITH APX
CHECKING IN AT -20 C. UPPER LEVEL TROUGH AXIS IS CURRENTLY MOVING
THROUGH THE CENTRAL GREAT LAKES. WATCHING SOUTHERN LAKE HURON SNOW
BAND(S) CLOSELY...AS EVEN KDTX RADAR PICKING UP THE SUBSTANTIAL ECHOS
(20-25 DBZ) AT THE 5500 FOOT LEVEL...WELL ABOVE THE STOUT
INVERSION INDICATED BY 12Z DTX SOUNDING...INDICATIVE OF THE LAKE
INFLUENCE. NAM/RAP13 STILL INDICTING THIS BAND WILL PUSH
SOUTH/SOUTHWEST THROUGH THE DAY BASED ON 925 MB OMEGA/CONVERGENCE
FIELDS...AND HOPEFULLY THE TRANSIENT NATURE WILL KEEP THE
LOCALIZED ACCUMULATIONS TO A COUPLE INCHES AROUND PORT HURON AREA.
FURTHER/INCREASING BOUNDARY LAYER MIXING/SUBSIDENCE BEHIND THE
UPPER LEVEL TROUGH AXIS THIS AFTERNOON AND BAND MOVING AWAY FROM
MOISTURE SOURCE SHOULD FURTHER DISRUPT THE ACTIVITY...HELPING TO
LIMIT THE ACCUMULATIONS FARTHER SOUTH. QUICK LOOK AT THE 12Z NAM
SHOWS ANOTHER LAKE BAND DEVELOPING OVER THE THUMB REGION THIS
EVENING WITH THE GOOD NORTHERLY FETCH OFF LAKE HURON...BUT
INVERSION HEIGHTS SLIGHTLY LOWER AND ADDITIONAL DRY AIR MAY LIMIT
ACCUMULATIONS TO INCH OR LESS...UNLIKE THE TWO INCHES SEEN IN
ELKTON THIS MORNING.

&&

.AVIATION...ISSUED 707 AM EDT FRI MAR 27 2015

A HIGH AMPLITUDE UPPER LEVEL TROUGH AND ASSOCIATED DEEP CYCLONIC
FLOW WILL KEEP MVFR TO LOWER VFR CIGS IN PLACE ACROSS ALL OF
SOUTHEASTERN MICHIGAN TODAY. FAVORABLE THERMODYNAMICS AND LOW
STABILITY IN THE LOWER PART OF THE ATMOSPHERE WILL SUPPORT SCATTERED
TO NUMEROUS SNOW SHOWERS AT THE TERMINALS FOR TODAY. TIMED SOME SNOW
SHOWERS ALONG A LOCALIZED SURFACE TROUGH AXIS THAT WILL SETTLE
SOUTHWARD THROUGH THE CWA DURING THE COURSE OF THE DAY. MAGNITUDE OF
THE DRY AIR AND STABLE MIDLEVEL PROFILE WILL LIMIT THE OVERALL
STRENGTH OF THE -SHSN ACTIVITY.

FOR DTW...FLURRIES ARE EXPECTED THIS MORNING. DAYTIME HEATING WILL
THEN ALLOW FOR A FAVORABLE ENVIRONMENT FOR FLARE UP IN SNOW SHOWER
ACTIVITY. CONFIDENCE REMAINS LOW IN OVERALL COVERAGE AND KEPT
DEGRADATION OF VSBY TO 6 MILES. MOST FAVORABLE TIMING AT DTW WILL BE
DURING THE AFTERNOON HOURS.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS AOB 5000 FT THROUGH MUCH OF THE FCST PERIOD.

&&

.PREV DISCUSSION...ISSUED 410 AM EDT FRI MAR 27 2015

SHORT TERM...TODAY AND TONIGHT

A FULL LATITUDE TROUGH OVER THE EASTERN CONTINENTAL UNITED STATES
WILL LEAD TO RAW CONDITIONS OVER SOUTHEASTERN MICHIGAN TODAY. THE
SPINE OF THE COLD AIR IS FORECASTED TO SETTLE INTO EASTERN LOWER
MICHIGAN BY 21Z THIS AFTERNOON. 850MB AND 925MB TEMPERATURES ARE
FORECASTED TO BE SOLIDLY OUTSIDE OF 1 SIGMA.  A STRAIGHT MIXING
TECHNIQUE SUPPORTS READINGS LIMITING OUT IN THE 20S. THE OUTGOING
FORECAST WILL SHADE A DEGREE OR TWO WARMER THAN THE AVAILABLE RAW
MODEL OUTPUT...MIDDLE 20S IN THE THUMB TO NEAR THE FREEZING MARK
ACROSS THE SOUTH...APPROXIMATELY 20 DEGREES BELOW NORMAL. A
SHARP...NORTH WIND WILL LEAD TO WINDCHILLS IN THE TEENS TO LOWER 20S
TODAY...AND IN THE LOWER SINGLE DIGITS TONIGHT.

WILL BE WATCHING A NUMBER OF THINGS FOR MORE ORGANIZED SNOW SHOWER
ACTIVITY TODAY. THE FIRST WILL BE ALONG A SURFACE CONVERGENCE
BOUNDARY ASSOCIATED WITH A WEST TO EAST SURFACE TROUGH AXIS THAT IS
FORECASTED TO PUSH SOUTHWARD THROUGH SOUTHEASTERN MICHIGAN DURING
THE COURSE OF THE ENTIRE DAY. RECENT RADAR IMAGERY FROM EXETER
ONTARIO SUGGESTS A FAIR AMOUNT OF REFLECTORS IN THE GENERAL LOCATION
OF THE AXIS THIS MORNING. HOWEVER...OVERSHOOTING OF THE RADAR BEAM
AT THESE DISTANCES LEADS TO A HIGH AMOUNT UNCERTAINTY. THE INHERITED
FORECAST STILL REMAINS VALID CALLING FOR SNOW SHOWERS
LIKELY/NUMEROUS IN THE THUMB THIS MORNING. AFTER THE MID TO LATE
MORNING ...FORECASTED LAPSE RATES SUPPORT A FLARE UP OF ACTIVITY
DUE TO THE DEEPENING OF THE BOUNDARY LAYER FROM DAYTIME HEATING.
PLAN VIEW EVOLUTION OF LL THETA E LAPSE RATES ALONG HIRES MODEL
OUTPUT SUGGESTS THIS POTENTIAL IS FOR ALL OF SOUTHEASTERN
MICHIGAN. THIS THERMODYNAMIC SUPPORT IS IN ADDITION TO A
CONTRACTION IN THE WAVELENGTH OF THE UPPER LEVEL TROUGH.
CONCENTRATED DCVA IN COMBINATION WITH THE LOCALIZED
CONVERGENCE/NEAR SURFACE TROUGH AXIS WILL LEAD TO ENOUGH FORCING
TO SUPPORT LIGHT SNOW SHOWER ACTIVITY ACROSS MUCH OF THE AREA THIS
AFTERNOON. THE SUPERSATURATION WRT ICE SIGNAL IS GOOD ALONG WITH
THE STEEP LAPSE RATE POCKET ENCAPSULATING THE -15C ISOTHERM. A
LIGHT DUSTING...TO MINOR ACCUMULATIONS OF GENERALLY LESS THAN ONE
INCH WILL BE POSSIBLE FOR MUCH OF THE CWA TODAY. IT REMAINS
POSSIBLE FOR SNOWFALL ACCUMULATIONS OF AN INCH OR GREATER FOR THE
THUMB REGION.

LONG TERM...

CONTINUED DEEP NORTHERLY FLOW WILL START SATURDAY BEFORE THE LARGE
AREA OF COLD HIGH PRESSURE BECOMES CENTERED OVER LOWER MICHIGAN
DURING THE REST OF THE DAY. THE WIND DIRECTION FROM LAKE HURON INTO
THE THUMB WILL FAVOR LINGERING BUT DIMINISHING LAKE EFFECT
POTENTIAL. MODEL SOUNDINGS INDICATE NEAR DRY ADIABATIC LAPSE RATES
BUT ALSO SHOW CONVECTIVE DEPTH FORCED QUICKLY BELOW 850 MB/5000 FT.
THIS MAY BE GOOD FOR SOME FLURRIES BUT MORE LIKELY JUST SOME
STRATOCU WITHIN A SHALLOW LAYER OF SATURATION NEAR -15C THAT MIXES
OUT BY AFTERNOON. THE BUILDING SURFACE HIGH AND BACKING LOW LEVEL
WIND FIELD WILL NUDGE THE LOW LEVEL THERMAL TROUGH EASTWARD DURING
THE AFTERNOON. THIS...COMBINED WITH FULL LATE MARCH SUN...WILL HELP
MAX TEMPS RISE TOWARD THE MID 30S...BUT STILL A SOLID 15 DEGREES
BELOW NORMAL. THE STAGE WILL THEN BE SET FOR A COLD SATURDAY NIGHT
WITH MIN TEMPS LIKELY OCCURRING AROUND MIDNIGHT BEFORE HIGH CLOUDS
THICKEN AND SOUTHWEST WIND INCREASES OVERNIGHT THROUGH SUNRISE
SUNDAY.

THE HIGH CLOUDS SATURDAY NIGHT WILL BE THE FIRST SIGN OF THE NEXT
LOW PRESSURE SYSTEM ARRIVING IN THE GREAT LAKES. THIS SYSTEM IS
STILL OFFSHORE OVER THE GULF OF ALASKA AND WILL BE MOVING INLAND
TONIGHT BEFORE POWERING THROUGH THE LONG WAVE RIDGE OVER THE ROCKIES
DURING SATURDAY. THERE IS IMPROVED AGREEMENT IN THE 00Z MODEL RUNS
WITH RESPECT TO TIMING THE ARRIVAL OF PRECIPITATION WITH THIS SYSTEM
SUNDAY AFTERNOON IN SE MICHIGAN. THE MOISTURE PROFILE WILL BE A
HYBRID OF MID LEVEL PACIFIC AND LOW LEVEL GULF MODIFIED CONTINENTAL
WHICH IS SEEMS ADEQUATE FOR THE 0.1-0.2 MODEL QPF AND LIKELY POPS
SUNDAY AFTERNOON AND EVENING. THERE WILL BE SOME WET BULB COOLING
POTENTIAL AT ONSET BUT THE NAM IS GIVING IT TOO MUCH CREDIT FOR
COOLING THE BOUNDARY LAYER ENOUGH FOR SNOW IN THE MIDDLE OF THE DAY.
A PROFILE MORE LIKE THE GFS IS PREFERRED AND HELPS RULE OUT A
RAIN/SNOW MIX UNTIL SUNDAY NIGHT WHEN COLDER AIR SPILLS BACK INTO
THE REGION BEHIND THE SYSTEM.

GLOBAL MODELS MAINTAIN THE FRONTAL ZONE NEARBY TO START NEXT WEEK
WITH A COUPLE MORE LOW PREDICTABILITY SHORT WAVES TRAVERSING THE NW
FLOW ALOFT. EXPECT COLD AIR INTRUSIONS TO BE LESS HARSH COMPARED TO
THIS WEEKEND. AT THIS POINT...A STRONGER LOW PRESSURE SYSTEM IS
PROJECTED AROUND THE WEDNESDAY PERIOD THAT HAS POTENTIAL TO ALTER
THE LARGE SCALE PATTERN ENOUGH TO LIFT TEMPERATURES BACK TO NORMAL
FOR THE SECOND HALF OF NEXT WEEK.

MARINE...

STRONG NORTH WIND OVER LAKE HURON AND LOWER MICHIGAN WILL CARRY AIR
COLD ENOUGH FOR SNOW SHOWERS TODAY AND TONIGHT. GUSTS NEAR 30 KNOTS
WILL THEN EASE BACK DURING SATURDAY AS HIGH PRESSURE SETTLES
OVERHEAD. SOUTHWEST WIND WILL THEN RAMP UP SATURDAY NIGHT INTO
SUNDAY AS THE NEXT LOW PRESSURE SYSTEM MOVES INTO THE MIDWEST AND
WESTERN GREAT LAKES. SOUTHWEST GUSTS AROUND 25 KNOTS WILL BRING BACK
ENOUGH WARM AIR FOR MOSTLY RAIN SUNDAY AFTERNOON AND EVENING. COLDER
AIR WILL RETURN MONDAY BUT NOT AS COLD AS THIS WEEKEND.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

UPDATE.......SF
AVIATION.....CB
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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




000
FXUS63 KDTX 271311
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
911 AM EDT FRI MAR 27 2015

.UPDATE...

12Z DTX SOUNDING INDICATED AN 850 MB TEMP OF -16 C...WITH APX
CHECKING IN AT -20 C. UPPER LEVEL TROUGH AXIS IS CURRENTLY MOVING
THROUGH THE CENTRAL GREAT LAKES. WATCHING SOUTHERN LAKE HURON SNOW
BAND(S) CLOSELY...AS EVEN KDTX RADAR PICKING UP THE SUBSTANTIAL ECHOS
(20-25 DBZ) AT THE 5500 FOOT LEVEL...WELL ABOVE THE STOUT
INVERSION INDICATED BY 12Z DTX SOUNDING...INDICATIVE OF THE LAKE
INFLUENCE. NAM/RAP13 STILL INDICTING THIS BAND WILL PUSH
SOUTH/SOUTHWEST THROUGH THE DAY BASED ON 925 MB OMEGA/CONVERGENCE
FIELDS...AND HOPEFULLY THE TRANSIENT NATURE WILL KEEP THE
LOCALIZED ACCUMULATIONS TO A COUPLE INCHES AROUND PORT HURON AREA.
FURTHER/INCREASING BOUNDARY LAYER MIXING/SUBSIDENCE BEHIND THE
UPPER LEVEL TROUGH AXIS THIS AFTERNOON AND BAND MOVING AWAY FROM
MOISTURE SOURCE SHOULD FURTHER DISRUPT THE ACTIVITY...HELPING TO
LIMIT THE ACCUMULATIONS FARTHER SOUTH. QUICK LOOK AT THE 12Z NAM
SHOWS ANOTHER LAKE BAND DEVELOPING OVER THE THUMB REGION THIS
EVENING WITH THE GOOD NORTHERLY FETCH OFF LAKE HURON...BUT
INVERSION HEIGHTS SLIGHTLY LOWER AND ADDITIONAL DRY AIR MAY LIMIT
ACCUMULATIONS TO INCH OR LESS...UNLIKE THE TWO INCHES SEEN IN
ELKTON THIS MORNING.

&&

.AVIATION...ISSUED 707 AM EDT FRI MAR 27 2015

A HIGH AMPLITUDE UPPER LEVEL TROUGH AND ASSOCIATED DEEP CYCLONIC
FLOW WILL KEEP MVFR TO LOWER VFR CIGS IN PLACE ACROSS ALL OF
SOUTHEASTERN MICHIGAN TODAY. FAVORABLE THERMODYNAMICS AND LOW
STABILITY IN THE LOWER PART OF THE ATMOSPHERE WILL SUPPORT SCATTERED
TO NUMEROUS SNOW SHOWERS AT THE TERMINALS FOR TODAY. TIMED SOME SNOW
SHOWERS ALONG A LOCALIZED SURFACE TROUGH AXIS THAT WILL SETTLE
SOUTHWARD THROUGH THE CWA DURING THE COURSE OF THE DAY. MAGNITUDE OF
THE DRY AIR AND STABLE MIDLEVEL PROFILE WILL LIMIT THE OVERALL
STRENGTH OF THE -SHSN ACTIVITY.

FOR DTW...FLURRIES ARE EXPECTED THIS MORNING. DAYTIME HEATING WILL
THEN ALLOW FOR A FAVORABLE ENVIRONMENT FOR FLARE UP IN SNOW SHOWER
ACTIVITY. CONFIDENCE REMAINS LOW IN OVERALL COVERAGE AND KEPT
DEGRADATION OF VSBY TO 6 MILES. MOST FAVORABLE TIMING AT DTW WILL BE
DURING THE AFTERNOON HOURS.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS AOB 5000 FT THROUGH MUCH OF THE FCST PERIOD.

&&

.PREV DISCUSSION...ISSUED 410 AM EDT FRI MAR 27 2015

SHORT TERM...TODAY AND TONIGHT

A FULL LATITUDE TROUGH OVER THE EASTERN CONTINENTAL UNITED STATES
WILL LEAD TO RAW CONDITIONS OVER SOUTHEASTERN MICHIGAN TODAY. THE
SPINE OF THE COLD AIR IS FORECASTED TO SETTLE INTO EASTERN LOWER
MICHIGAN BY 21Z THIS AFTERNOON. 850MB AND 925MB TEMPERATURES ARE
FORECASTED TO BE SOLIDLY OUTSIDE OF 1 SIGMA.  A STRAIGHT MIXING
TECHNIQUE SUPPORTS READINGS LIMITING OUT IN THE 20S. THE OUTGOING
FORECAST WILL SHADE A DEGREE OR TWO WARMER THAN THE AVAILABLE RAW
MODEL OUTPUT...MIDDLE 20S IN THE THUMB TO NEAR THE FREEZING MARK
ACROSS THE SOUTH...APPROXIMATELY 20 DEGREES BELOW NORMAL. A
SHARP...NORTH WIND WILL LEAD TO WINDCHILLS IN THE TEENS TO LOWER 20S
TODAY...AND IN THE LOWER SINGLE DIGITS TONIGHT.

WILL BE WATCHING A NUMBER OF THINGS FOR MORE ORGANIZED SNOW SHOWER
ACTIVITY TODAY. THE FIRST WILL BE ALONG A SURFACE CONVERGENCE
BOUNDARY ASSOCIATED WITH A WEST TO EAST SURFACE TROUGH AXIS THAT IS
FORECASTED TO PUSH SOUTHWARD THROUGH SOUTHEASTERN MICHIGAN DURING
THE COURSE OF THE ENTIRE DAY. RECENT RADAR IMAGERY FROM EXETER
ONTARIO SUGGESTS A FAIR AMOUNT OF REFLECTORS IN THE GENERAL LOCATION
OF THE AXIS THIS MORNING. HOWEVER...OVERSHOOTING OF THE RADAR BEAM
AT THESE DISTANCES LEADS TO A HIGH AMOUNT UNCERTAINTY. THE INHERITED
FORECAST STILL REMAINS VALID CALLING FOR SNOW SHOWERS
LIKELY/NUMEROUS IN THE THUMB THIS MORNING. AFTER THE MID TO LATE
MORNING ...FORECASTED LAPSE RATES SUPPORT A FLARE UP OF ACTIVITY
DUE TO THE DEEPENING OF THE BOUNDARY LAYER FROM DAYTIME HEATING.
PLAN VIEW EVOLUTION OF LL THETA E LAPSE RATES ALONG HIRES MODEL
OUTPUT SUGGESTS THIS POTENTIAL IS FOR ALL OF SOUTHEASTERN
MICHIGAN. THIS THERMODYNAMIC SUPPORT IS IN ADDITION TO A
CONTRACTION IN THE WAVELENGTH OF THE UPPER LEVEL TROUGH.
CONCENTRATED DCVA IN COMBINATION WITH THE LOCALIZED
CONVERGENCE/NEAR SURFACE TROUGH AXIS WILL LEAD TO ENOUGH FORCING
TO SUPPORT LIGHT SNOW SHOWER ACTIVITY ACROSS MUCH OF THE AREA THIS
AFTERNOON. THE SUPERSATURATION WRT ICE SIGNAL IS GOOD ALONG WITH
THE STEEP LAPSE RATE POCKET ENCAPSULATING THE -15C ISOTHERM. A
LIGHT DUSTING...TO MINOR ACCUMULATIONS OF GENERALLY LESS THAN ONE
INCH WILL BE POSSIBLE FOR MUCH OF THE CWA TODAY. IT REMAINS
POSSIBLE FOR SNOWFALL ACCUMULATIONS OF AN INCH OR GREATER FOR THE
THUMB REGION.

LONG TERM...

CONTINUED DEEP NORTHERLY FLOW WILL START SATURDAY BEFORE THE LARGE
AREA OF COLD HIGH PRESSURE BECOMES CENTERED OVER LOWER MICHIGAN
DURING THE REST OF THE DAY. THE WIND DIRECTION FROM LAKE HURON INTO
THE THUMB WILL FAVOR LINGERING BUT DIMINISHING LAKE EFFECT
POTENTIAL. MODEL SOUNDINGS INDICATE NEAR DRY ADIABATIC LAPSE RATES
BUT ALSO SHOW CONVECTIVE DEPTH FORCED QUICKLY BELOW 850 MB/5000 FT.
THIS MAY BE GOOD FOR SOME FLURRIES BUT MORE LIKELY JUST SOME
STRATOCU WITHIN A SHALLOW LAYER OF SATURATION NEAR -15C THAT MIXES
OUT BY AFTERNOON. THE BUILDING SURFACE HIGH AND BACKING LOW LEVEL
WIND FIELD WILL NUDGE THE LOW LEVEL THERMAL TROUGH EASTWARD DURING
THE AFTERNOON. THIS...COMBINED WITH FULL LATE MARCH SUN...WILL HELP
MAX TEMPS RISE TOWARD THE MID 30S...BUT STILL A SOLID 15 DEGREES
BELOW NORMAL. THE STAGE WILL THEN BE SET FOR A COLD SATURDAY NIGHT
WITH MIN TEMPS LIKELY OCCURRING AROUND MIDNIGHT BEFORE HIGH CLOUDS
THICKEN AND SOUTHWEST WIND INCREASES OVERNIGHT THROUGH SUNRISE
SUNDAY.

THE HIGH CLOUDS SATURDAY NIGHT WILL BE THE FIRST SIGN OF THE NEXT
LOW PRESSURE SYSTEM ARRIVING IN THE GREAT LAKES. THIS SYSTEM IS
STILL OFFSHORE OVER THE GULF OF ALASKA AND WILL BE MOVING INLAND
TONIGHT BEFORE POWERING THROUGH THE LONG WAVE RIDGE OVER THE ROCKIES
DURING SATURDAY. THERE IS IMPROVED AGREEMENT IN THE 00Z MODEL RUNS
WITH RESPECT TO TIMING THE ARRIVAL OF PRECIPITATION WITH THIS SYSTEM
SUNDAY AFTERNOON IN SE MICHIGAN. THE MOISTURE PROFILE WILL BE A
HYBRID OF MID LEVEL PACIFIC AND LOW LEVEL GULF MODIFIED CONTINENTAL
WHICH IS SEEMS ADEQUATE FOR THE 0.1-0.2 MODEL QPF AND LIKELY POPS
SUNDAY AFTERNOON AND EVENING. THERE WILL BE SOME WET BULB COOLING
POTENTIAL AT ONSET BUT THE NAM IS GIVING IT TOO MUCH CREDIT FOR
COOLING THE BOUNDARY LAYER ENOUGH FOR SNOW IN THE MIDDLE OF THE DAY.
A PROFILE MORE LIKE THE GFS IS PREFERRED AND HELPS RULE OUT A
RAIN/SNOW MIX UNTIL SUNDAY NIGHT WHEN COLDER AIR SPILLS BACK INTO
THE REGION BEHIND THE SYSTEM.

GLOBAL MODELS MAINTAIN THE FRONTAL ZONE NEARBY TO START NEXT WEEK
WITH A COUPLE MORE LOW PREDICTABILITY SHORT WAVES TRAVERSING THE NW
FLOW ALOFT. EXPECT COLD AIR INTRUSIONS TO BE LESS HARSH COMPARED TO
THIS WEEKEND. AT THIS POINT...A STRONGER LOW PRESSURE SYSTEM IS
PROJECTED AROUND THE WEDNESDAY PERIOD THAT HAS POTENTIAL TO ALTER
THE LARGE SCALE PATTERN ENOUGH TO LIFT TEMPERATURES BACK TO NORMAL
FOR THE SECOND HALF OF NEXT WEEK.

MARINE...

STRONG NORTH WIND OVER LAKE HURON AND LOWER MICHIGAN WILL CARRY AIR
COLD ENOUGH FOR SNOW SHOWERS TODAY AND TONIGHT. GUSTS NEAR 30 KNOTS
WILL THEN EASE BACK DURING SATURDAY AS HIGH PRESSURE SETTLES
OVERHEAD. SOUTHWEST WIND WILL THEN RAMP UP SATURDAY NIGHT INTO
SUNDAY AS THE NEXT LOW PRESSURE SYSTEM MOVES INTO THE MIDWEST AND
WESTERN GREAT LAKES. SOUTHWEST GUSTS AROUND 25 KNOTS WILL BRING BACK
ENOUGH WARM AIR FOR MOSTLY RAIN SUNDAY AFTERNOON AND EVENING. COLDER
AIR WILL RETURN MONDAY BUT NOT AS COLD AS THIS WEEKEND.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

UPDATE.......SF
AVIATION.....CB
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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





000
FXUS63 KDTX 271311
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
911 AM EDT FRI MAR 27 2015

.UPDATE...

12Z DTX SOUNDING INDICATED AN 850 MB TEMP OF -16 C...WITH APX
CHECKING IN AT -20 C. UPPER LEVEL TROUGH AXIS IS CURRENTLY MOVING
THROUGH THE CENTRAL GREAT LAKES. WATCHING SOUTHERN LAKE HURON SNOW
BAND(S) CLOSELY...AS EVEN KDTX RADAR PICKING UP THE SUBSTANTIAL ECHOS
(20-25 DBZ) AT THE 5500 FOOT LEVEL...WELL ABOVE THE STOUT
INVERSION INDICATED BY 12Z DTX SOUNDING...INDICATIVE OF THE LAKE
INFLUENCE. NAM/RAP13 STILL INDICTING THIS BAND WILL PUSH
SOUTH/SOUTHWEST THROUGH THE DAY BASED ON 925 MB OMEGA/CONVERGENCE
FIELDS...AND HOPEFULLY THE TRANSIENT NATURE WILL KEEP THE
LOCALIZED ACCUMULATIONS TO A COUPLE INCHES AROUND PORT HURON AREA.
FURTHER/INCREASING BOUNDARY LAYER MIXING/SUBSIDENCE BEHIND THE
UPPER LEVEL TROUGH AXIS THIS AFTERNOON AND BAND MOVING AWAY FROM
MOISTURE SOURCE SHOULD FURTHER DISRUPT THE ACTIVITY...HELPING TO
LIMIT THE ACCUMULATIONS FARTHER SOUTH. QUICK LOOK AT THE 12Z NAM
SHOWS ANOTHER LAKE BAND DEVELOPING OVER THE THUMB REGION THIS
EVENING WITH THE GOOD NORTHERLY FETCH OFF LAKE HURON...BUT
INVERSION HEIGHTS SLIGHTLY LOWER AND ADDITIONAL DRY AIR MAY LIMIT
ACCUMULATIONS TO INCH OR LESS...UNLIKE THE TWO INCHES SEEN IN
ELKTON THIS MORNING.

&&

.AVIATION...ISSUED 707 AM EDT FRI MAR 27 2015

A HIGH AMPLITUDE UPPER LEVEL TROUGH AND ASSOCIATED DEEP CYCLONIC
FLOW WILL KEEP MVFR TO LOWER VFR CIGS IN PLACE ACROSS ALL OF
SOUTHEASTERN MICHIGAN TODAY. FAVORABLE THERMODYNAMICS AND LOW
STABILITY IN THE LOWER PART OF THE ATMOSPHERE WILL SUPPORT SCATTERED
TO NUMEROUS SNOW SHOWERS AT THE TERMINALS FOR TODAY. TIMED SOME SNOW
SHOWERS ALONG A LOCALIZED SURFACE TROUGH AXIS THAT WILL SETTLE
SOUTHWARD THROUGH THE CWA DURING THE COURSE OF THE DAY. MAGNITUDE OF
THE DRY AIR AND STABLE MIDLEVEL PROFILE WILL LIMIT THE OVERALL
STRENGTH OF THE -SHSN ACTIVITY.

FOR DTW...FLURRIES ARE EXPECTED THIS MORNING. DAYTIME HEATING WILL
THEN ALLOW FOR A FAVORABLE ENVIRONMENT FOR FLARE UP IN SNOW SHOWER
ACTIVITY. CONFIDENCE REMAINS LOW IN OVERALL COVERAGE AND KEPT
DEGRADATION OF VSBY TO 6 MILES. MOST FAVORABLE TIMING AT DTW WILL BE
DURING THE AFTERNOON HOURS.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS AOB 5000 FT THROUGH MUCH OF THE FCST PERIOD.

&&

.PREV DISCUSSION...ISSUED 410 AM EDT FRI MAR 27 2015

SHORT TERM...TODAY AND TONIGHT

A FULL LATITUDE TROUGH OVER THE EASTERN CONTINENTAL UNITED STATES
WILL LEAD TO RAW CONDITIONS OVER SOUTHEASTERN MICHIGAN TODAY. THE
SPINE OF THE COLD AIR IS FORECASTED TO SETTLE INTO EASTERN LOWER
MICHIGAN BY 21Z THIS AFTERNOON. 850MB AND 925MB TEMPERATURES ARE
FORECASTED TO BE SOLIDLY OUTSIDE OF 1 SIGMA.  A STRAIGHT MIXING
TECHNIQUE SUPPORTS READINGS LIMITING OUT IN THE 20S. THE OUTGOING
FORECAST WILL SHADE A DEGREE OR TWO WARMER THAN THE AVAILABLE RAW
MODEL OUTPUT...MIDDLE 20S IN THE THUMB TO NEAR THE FREEZING MARK
ACROSS THE SOUTH...APPROXIMATELY 20 DEGREES BELOW NORMAL. A
SHARP...NORTH WIND WILL LEAD TO WINDCHILLS IN THE TEENS TO LOWER 20S
TODAY...AND IN THE LOWER SINGLE DIGITS TONIGHT.

WILL BE WATCHING A NUMBER OF THINGS FOR MORE ORGANIZED SNOW SHOWER
ACTIVITY TODAY. THE FIRST WILL BE ALONG A SURFACE CONVERGENCE
BOUNDARY ASSOCIATED WITH A WEST TO EAST SURFACE TROUGH AXIS THAT IS
FORECASTED TO PUSH SOUTHWARD THROUGH SOUTHEASTERN MICHIGAN DURING
THE COURSE OF THE ENTIRE DAY. RECENT RADAR IMAGERY FROM EXETER
ONTARIO SUGGESTS A FAIR AMOUNT OF REFLECTORS IN THE GENERAL LOCATION
OF THE AXIS THIS MORNING. HOWEVER...OVERSHOOTING OF THE RADAR BEAM
AT THESE DISTANCES LEADS TO A HIGH AMOUNT UNCERTAINTY. THE INHERITED
FORECAST STILL REMAINS VALID CALLING FOR SNOW SHOWERS
LIKELY/NUMEROUS IN THE THUMB THIS MORNING. AFTER THE MID TO LATE
MORNING ...FORECASTED LAPSE RATES SUPPORT A FLARE UP OF ACTIVITY
DUE TO THE DEEPENING OF THE BOUNDARY LAYER FROM DAYTIME HEATING.
PLAN VIEW EVOLUTION OF LL THETA E LAPSE RATES ALONG HIRES MODEL
OUTPUT SUGGESTS THIS POTENTIAL IS FOR ALL OF SOUTHEASTERN
MICHIGAN. THIS THERMODYNAMIC SUPPORT IS IN ADDITION TO A
CONTRACTION IN THE WAVELENGTH OF THE UPPER LEVEL TROUGH.
CONCENTRATED DCVA IN COMBINATION WITH THE LOCALIZED
CONVERGENCE/NEAR SURFACE TROUGH AXIS WILL LEAD TO ENOUGH FORCING
TO SUPPORT LIGHT SNOW SHOWER ACTIVITY ACROSS MUCH OF THE AREA THIS
AFTERNOON. THE SUPERSATURATION WRT ICE SIGNAL IS GOOD ALONG WITH
THE STEEP LAPSE RATE POCKET ENCAPSULATING THE -15C ISOTHERM. A
LIGHT DUSTING...TO MINOR ACCUMULATIONS OF GENERALLY LESS THAN ONE
INCH WILL BE POSSIBLE FOR MUCH OF THE CWA TODAY. IT REMAINS
POSSIBLE FOR SNOWFALL ACCUMULATIONS OF AN INCH OR GREATER FOR THE
THUMB REGION.

LONG TERM...

CONTINUED DEEP NORTHERLY FLOW WILL START SATURDAY BEFORE THE LARGE
AREA OF COLD HIGH PRESSURE BECOMES CENTERED OVER LOWER MICHIGAN
DURING THE REST OF THE DAY. THE WIND DIRECTION FROM LAKE HURON INTO
THE THUMB WILL FAVOR LINGERING BUT DIMINISHING LAKE EFFECT
POTENTIAL. MODEL SOUNDINGS INDICATE NEAR DRY ADIABATIC LAPSE RATES
BUT ALSO SHOW CONVECTIVE DEPTH FORCED QUICKLY BELOW 850 MB/5000 FT.
THIS MAY BE GOOD FOR SOME FLURRIES BUT MORE LIKELY JUST SOME
STRATOCU WITHIN A SHALLOW LAYER OF SATURATION NEAR -15C THAT MIXES
OUT BY AFTERNOON. THE BUILDING SURFACE HIGH AND BACKING LOW LEVEL
WIND FIELD WILL NUDGE THE LOW LEVEL THERMAL TROUGH EASTWARD DURING
THE AFTERNOON. THIS...COMBINED WITH FULL LATE MARCH SUN...WILL HELP
MAX TEMPS RISE TOWARD THE MID 30S...BUT STILL A SOLID 15 DEGREES
BELOW NORMAL. THE STAGE WILL THEN BE SET FOR A COLD SATURDAY NIGHT
WITH MIN TEMPS LIKELY OCCURRING AROUND MIDNIGHT BEFORE HIGH CLOUDS
THICKEN AND SOUTHWEST WIND INCREASES OVERNIGHT THROUGH SUNRISE
SUNDAY.

THE HIGH CLOUDS SATURDAY NIGHT WILL BE THE FIRST SIGN OF THE NEXT
LOW PRESSURE SYSTEM ARRIVING IN THE GREAT LAKES. THIS SYSTEM IS
STILL OFFSHORE OVER THE GULF OF ALASKA AND WILL BE MOVING INLAND
TONIGHT BEFORE POWERING THROUGH THE LONG WAVE RIDGE OVER THE ROCKIES
DURING SATURDAY. THERE IS IMPROVED AGREEMENT IN THE 00Z MODEL RUNS
WITH RESPECT TO TIMING THE ARRIVAL OF PRECIPITATION WITH THIS SYSTEM
SUNDAY AFTERNOON IN SE MICHIGAN. THE MOISTURE PROFILE WILL BE A
HYBRID OF MID LEVEL PACIFIC AND LOW LEVEL GULF MODIFIED CONTINENTAL
WHICH IS SEEMS ADEQUATE FOR THE 0.1-0.2 MODEL QPF AND LIKELY POPS
SUNDAY AFTERNOON AND EVENING. THERE WILL BE SOME WET BULB COOLING
POTENTIAL AT ONSET BUT THE NAM IS GIVING IT TOO MUCH CREDIT FOR
COOLING THE BOUNDARY LAYER ENOUGH FOR SNOW IN THE MIDDLE OF THE DAY.
A PROFILE MORE LIKE THE GFS IS PREFERRED AND HELPS RULE OUT A
RAIN/SNOW MIX UNTIL SUNDAY NIGHT WHEN COLDER AIR SPILLS BACK INTO
THE REGION BEHIND THE SYSTEM.

GLOBAL MODELS MAINTAIN THE FRONTAL ZONE NEARBY TO START NEXT WEEK
WITH A COUPLE MORE LOW PREDICTABILITY SHORT WAVES TRAVERSING THE NW
FLOW ALOFT. EXPECT COLD AIR INTRUSIONS TO BE LESS HARSH COMPARED TO
THIS WEEKEND. AT THIS POINT...A STRONGER LOW PRESSURE SYSTEM IS
PROJECTED AROUND THE WEDNESDAY PERIOD THAT HAS POTENTIAL TO ALTER
THE LARGE SCALE PATTERN ENOUGH TO LIFT TEMPERATURES BACK TO NORMAL
FOR THE SECOND HALF OF NEXT WEEK.

MARINE...

STRONG NORTH WIND OVER LAKE HURON AND LOWER MICHIGAN WILL CARRY AIR
COLD ENOUGH FOR SNOW SHOWERS TODAY AND TONIGHT. GUSTS NEAR 30 KNOTS
WILL THEN EASE BACK DURING SATURDAY AS HIGH PRESSURE SETTLES
OVERHEAD. SOUTHWEST WIND WILL THEN RAMP UP SATURDAY NIGHT INTO
SUNDAY AS THE NEXT LOW PRESSURE SYSTEM MOVES INTO THE MIDWEST AND
WESTERN GREAT LAKES. SOUTHWEST GUSTS AROUND 25 KNOTS WILL BRING BACK
ENOUGH WARM AIR FOR MOSTLY RAIN SUNDAY AFTERNOON AND EVENING. COLDER
AIR WILL RETURN MONDAY BUT NOT AS COLD AS THIS WEEKEND.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

UPDATE.......SF
AVIATION.....CB
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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




000
FXUS63 KDTX 271107
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
707 AM EDT FRI MAR 27 2015

.AVIATION...

A HIGH AMPLITUDE UPPER LEVEL TROUGH AND ASSOCIATED DEEP CYCLONIC
FLOW WILL KEEP MVFR TO LOWER VFR CIGS IN PLACE ACROSS ALL OF
SOUTHEASTERN MICHIGAN TODAY. FAVORABLE THERMODYNAMICS AND LOW
STABILITY IN THE LOWER PART OF THE ATMOSPHERE WILL SUPPORT SCATTERED
TO NUMEROUS SNOW SHOWERS AT THE TERMINALS FOR TODAY. TIMED SOME SNOW
SHOWERS ALONG A LOCALIZED SURFACE TROUGH AXIS THAT WILL SETTLE
SOUTHWARD THROUGH THE CWA DURING THE COURSE OF THE DAY. MAGNITUDE OF
THE DRY AIR AND STABLE MIDLEVEL PROFILE WILL LIMIT THE OVERALL
STRENGTH OF THE -SHSN ACTIVITY.

FOR DTW...FLURRIES ARE EXPECTED THIS MORNING. DAYTIME HEATING WILL
THEN ALLOW FOR A FAVORABLE ENVIRONMENT FOR FLARE UP IN SNOW SHOWER
ACTIVITY. CONFIDENCE REMAINS LOW IN OVERALL COVERAGE AND KEPT
DEGRADATION OF VSBY TO 6 MILES. MOST FAVORABLE TIMING AT DTW WILL BE
DURING THE AFTERNOON HOURS.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS AOB 5000 FT THROUGH MUCH OF THE FCST PERIOD.

&&

.PREV DISCUSSION...ISSUED 410 AM EDT FRI MAR 27 2015

SHORT TERM...TODAY AND TONIGHT

A FULL LATITUDE TROUGH OVER THE EASTERN CONTINENTAL UNITED STATES
WILL LEAD TO RAW CONDITIONS OVER SOUTHEASTERN MICHIGAN TODAY. THE
SPINE OF THE COLD AIR IS FORECASTED TO SETTLE INTO EASTERN LOWER
MICHIGAN BY 21Z THIS AFTERNOON. 850MB AND 925MB TEMPERATURES ARE
FORECASTED TO BE SOLIDLY OUTSIDE OF 1 SIGMA.  A STRAIGHT MIXING
TECHNIQUE SUPPORTS READINGS LIMITING OUT IN THE 20S. THE OUTGOING
FORECAST WILL SHADE A DEGREE OR TWO WARMER THAN THE AVAILABLE RAW
MODEL OUTPUT...MIDDLE 20S IN THE THUMB TO NEAR THE FREEZING MARK
ACROSS THE SOUTH...APPROXIMATELY 20 DEGREES BELOW NORMAL. A
SHARP...NORTH WIND WILL LEAD TO WINDCHILLS IN THE TEENS TO LOWER 20S
TODAY...AND IN THE LOWER SINGLE DIGITS TONIGHT.

WILL BE WATCHING A NUMBER OF THINGS FOR MORE ORGANIZED SNOW SHOWER
ACTIVITY TODAY. THE FIRST WILL BE ALONG A SURFACE CONVERGENCE
BOUNDARY ASSOCIATED WITH A WEST TO EAST SURFACE TROUGH AXIS THAT IS
FORECASTED TO PUSH SOUTHWARD THROUGH SOUTHEASTERN MICHIGAN DURING
THE COURSE OF THE ENTIRE DAY. RECENT RADAR IMAGERY FROM EXETER
ONTARIO SUGGESTS A FAIR AMOUNT OF REFLECTORS IN THE GENERAL LOCATION
OF THE AXIS THIS MORNING. HOWEVER...OVERSHOOTING OF THE RADAR BEAM
AT THESE DISTANCES LEADS TO A HIGH AMOUNT UNCERTAINTY. THE INHERITED
FORECAST STILL REMAINS VALID CALLING FOR SNOW SHOWERS
LIKELY/NUMEROUS IN THE THUMB THIS MORNING. AFTER THE MID TO LATE
MORNING ...FORECASTED LAPSE RATES SUPPORT A FLARE UP OF ACTIVITY
DUE TO THE DEEPENING OF THE BOUNDARY LAYER FROM DAYTIME HEATING.
PLAN VIEW EVOLUTION OF LL THETA E LAPSE RATES ALONG HIRES MODEL
OUTPUT SUGGESTS THIS POTENTIAL IS FOR ALL OF SOUTHEASTERN
MICHIGAN. THIS THERMODYNAMIC SUPPORT IS IN ADDITION TO A
CONTRACTION IN THE WAVELENGTH OF THE UPPER LEVEL TROUGH.
CONCENTRATED DCVA IN COMBINATION WITH THE LOCALIZED
CONVERGENCE/NEAR SURFACE TROUGH AXIS WILL LEAD TO ENOUGH FORCING
TO SUPPORT LIGHT SNOW SHOWER ACTIVITY ACROSS MUCH OF THE AREA THIS
AFTERNOON. THE SUPERSATURATION WRT ICE SIGNAL IS GOOD ALONG WITH
THE STEEP LAPSE RATE POCKET ENCAPSULATING THE -15C ISOTHERM. A
LIGHT DUSTING...TO MINOR ACCUMULATIONS OF GENERALLY LESS THAN ONE
INCH WILL BE POSSIBLE FOR MUCH OF THE CWA TODAY. IT REMAINS
POSSIBLE FOR SNOWFALL ACCUMULATIONS OF AN INCH OR GREATER FOR THE
THUMB REGION.

LONG TERM...

CONTINUED DEEP NORTHERLY FLOW WILL START SATURDAY BEFORE THE LARGE
AREA OF COLD HIGH PRESSURE BECOMES CENTERED OVER LOWER MICHIGAN
DURING THE REST OF THE DAY. THE WIND DIRECTION FROM LAKE HURON INTO
THE THUMB WILL FAVOR LINGERING BUT DIMINISHING LAKE EFFECT
POTENTIAL. MODEL SOUNDINGS INDICATE NEAR DRY ADIABATIC LAPSE RATES
BUT ALSO SHOW CONVECTIVE DEPTH FORCED QUICKLY BELOW 850 MB/5000 FT.
THIS MAY BE GOOD FOR SOME FLURRIES BUT MORE LIKELY JUST SOME
STRATOCU WITHIN A SHALLOW LAYER OF SATURATION NEAR -15C THAT MIXES
OUT BY AFTERNOON. THE BUILDING SURFACE HIGH AND BACKING LOW LEVEL
WIND FIELD WILL NUDGE THE LOW LEVEL THERMAL TROUGH EASTWARD DURING
THE AFTERNOON. THIS...COMBINED WITH FULL LATE MARCH SUN...WILL HELP
MAX TEMPS RISE TOWARD THE MID 30S...BUT STILL A SOLID 15 DEGREES
BELOW NORMAL. THE STAGE WILL THEN BE SET FOR A COLD SATURDAY NIGHT
WITH MIN TEMPS LIKELY OCCURRING AROUND MIDNIGHT BEFORE HIGH CLOUDS
THICKEN AND SOUTHWEST WIND INCREASES OVERNIGHT THROUGH SUNRISE
SUNDAY.

THE HIGH CLOUDS SATURDAY NIGHT WILL BE THE FIRST SIGN OF THE NEXT
LOW PRESSURE SYSTEM ARRIVING IN THE GREAT LAKES. THIS SYSTEM IS
STILL OFFSHORE OVER THE GULF OF ALASKA AND WILL BE MOVING INLAND
TONIGHT BEFORE POWERING THROUGH THE LONG WAVE RIDGE OVER THE ROCKIES
DURING SATURDAY. THERE IS IMPROVED AGREEMENT IN THE 00Z MODEL RUNS
WITH RESPECT TO TIMING THE ARRIVAL OF PRECIPITATION WITH THIS SYSTEM
SUNDAY AFTERNOON IN SE MICHIGAN. THE MOISTURE PROFILE WILL BE A
HYBRID OF MID LEVEL PACIFIC AND LOW LEVEL GULF MODIFIED CONTINENTAL
WHICH IS SEEMS ADEQUATE FOR THE 0.1-0.2 MODEL QPF AND LIKELY POPS
SUNDAY AFTERNOON AND EVENING. THERE WILL BE SOME WET BULB COOLING
POTENTIAL AT ONSET BUT THE NAM IS GIVING IT TOO MUCH CREDIT FOR
COOLING THE BOUNDARY LAYER ENOUGH FOR SNOW IN THE MIDDLE OF THE DAY.
A PROFILE MORE LIKE THE GFS IS PREFERRED AND HELPS RULE OUT A
RAIN/SNOW MIX UNTIL SUNDAY NIGHT WHEN COLDER AIR SPILLS BACK INTO
THE REGION BEHIND THE SYSTEM.

GLOBAL MODELS MAINTAIN THE FRONTAL ZONE NEARBY TO START NEXT WEEK
WITH A COUPLE MORE LOW PREDICTABILITY SHORT WAVES TRAVERSING THE NW
FLOW ALOFT. EXPECT COLD AIR INTRUSIONS TO BE LESS HARSH COMPARED TO
THIS WEEKEND. AT THIS POINT...A STRONGER LOW PRESSURE SYSTEM IS
PROJECTED AROUND THE WEDNESDAY PERIOD THAT HAS POTENTIAL TO ALTER
THE LARGE SCALE PATTERN ENOUGH TO LIFT TEMPERATURES BACK TO NORMAL
FOR THE SECOND HALF OF NEXT WEEK.

MARINE...

STRONG NORTH WIND OVER LAKE HURON AND LOWER MICHIGAN WILL CARRY AIR
COLD ENOUGH FOR SNOW SHOWERS TODAY AND TONIGHT. GUSTS NEAR 30 KNOTS
WILL THEN EASE BACK DURING SATURDAY AS HIGH PRESSURE SETTLES
OVERHEAD. SOUTHWEST WIND WILL THEN RAMP UP SATURDAY NIGHT INTO
SUNDAY AS THE NEXT LOW PRESSURE SYSTEM MOVES INTO THE MIDWEST AND
WESTERN GREAT LAKES. SOUTHWEST GUSTS AROUND 25 KNOTS WILL BRING BACK
ENOUGH WARM AIR FOR MOSTLY RAIN SUNDAY AFTERNOON AND EVENING. COLDER
AIR WILL RETURN MONDAY BUT NOT AS COLD AS THIS WEEKEND.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

MI...NONE.

LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.

MICHIGAN WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....CB
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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





000
FXUS63 KDTX 271107
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
707 AM EDT FRI MAR 27 2015

.AVIATION...

A HIGH AMPLITUDE UPPER LEVEL TROUGH AND ASSOCIATED DEEP CYCLONIC
FLOW WILL KEEP MVFR TO LOWER VFR CIGS IN PLACE ACROSS ALL OF
SOUTHEASTERN MICHIGAN TODAY. FAVORABLE THERMODYNAMICS AND LOW
STABILITY IN THE LOWER PART OF THE ATMOSPHERE WILL SUPPORT SCATTERED
TO NUMEROUS SNOW SHOWERS AT THE TERMINALS FOR TODAY. TIMED SOME SNOW
SHOWERS ALONG A LOCALIZED SURFACE TROUGH AXIS THAT WILL SETTLE
SOUTHWARD THROUGH THE CWA DURING THE COURSE OF THE DAY. MAGNITUDE OF
THE DRY AIR AND STABLE MIDLEVEL PROFILE WILL LIMIT THE OVERALL
STRENGTH OF THE -SHSN ACTIVITY.

FOR DTW...FLURRIES ARE EXPECTED THIS MORNING. DAYTIME HEATING WILL
THEN ALLOW FOR A FAVORABLE ENVIRONMENT FOR FLARE UP IN SNOW SHOWER
ACTIVITY. CONFIDENCE REMAINS LOW IN OVERALL COVERAGE AND KEPT
DEGRADATION OF VSBY TO 6 MILES. MOST FAVORABLE TIMING AT DTW WILL BE
DURING THE AFTERNOON HOURS.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS AOB 5000 FT THROUGH MUCH OF THE FCST PERIOD.

&&

.PREV DISCUSSION...ISSUED 410 AM EDT FRI MAR 27 2015

SHORT TERM...TODAY AND TONIGHT

A FULL LATITUDE TROUGH OVER THE EASTERN CONTINENTAL UNITED STATES
WILL LEAD TO RAW CONDITIONS OVER SOUTHEASTERN MICHIGAN TODAY. THE
SPINE OF THE COLD AIR IS FORECASTED TO SETTLE INTO EASTERN LOWER
MICHIGAN BY 21Z THIS AFTERNOON. 850MB AND 925MB TEMPERATURES ARE
FORECASTED TO BE SOLIDLY OUTSIDE OF 1 SIGMA.  A STRAIGHT MIXING
TECHNIQUE SUPPORTS READINGS LIMITING OUT IN THE 20S. THE OUTGOING
FORECAST WILL SHADE A DEGREE OR TWO WARMER THAN THE AVAILABLE RAW
MODEL OUTPUT...MIDDLE 20S IN THE THUMB TO NEAR THE FREEZING MARK
ACROSS THE SOUTH...APPROXIMATELY 20 DEGREES BELOW NORMAL. A
SHARP...NORTH WIND WILL LEAD TO WINDCHILLS IN THE TEENS TO LOWER 20S
TODAY...AND IN THE LOWER SINGLE DIGITS TONIGHT.

WILL BE WATCHING A NUMBER OF THINGS FOR MORE ORGANIZED SNOW SHOWER
ACTIVITY TODAY. THE FIRST WILL BE ALONG A SURFACE CONVERGENCE
BOUNDARY ASSOCIATED WITH A WEST TO EAST SURFACE TROUGH AXIS THAT IS
FORECASTED TO PUSH SOUTHWARD THROUGH SOUTHEASTERN MICHIGAN DURING
THE COURSE OF THE ENTIRE DAY. RECENT RADAR IMAGERY FROM EXETER
ONTARIO SUGGESTS A FAIR AMOUNT OF REFLECTORS IN THE GENERAL LOCATION
OF THE AXIS THIS MORNING. HOWEVER...OVERSHOOTING OF THE RADAR BEAM
AT THESE DISTANCES LEADS TO A HIGH AMOUNT UNCERTAINTY. THE INHERITED
FORECAST STILL REMAINS VALID CALLING FOR SNOW SHOWERS
LIKELY/NUMEROUS IN THE THUMB THIS MORNING. AFTER THE MID TO LATE
MORNING ...FORECASTED LAPSE RATES SUPPORT A FLARE UP OF ACTIVITY
DUE TO THE DEEPENING OF THE BOUNDARY LAYER FROM DAYTIME HEATING.
PLAN VIEW EVOLUTION OF LL THETA E LAPSE RATES ALONG HIRES MODEL
OUTPUT SUGGESTS THIS POTENTIAL IS FOR ALL OF SOUTHEASTERN
MICHIGAN. THIS THERMODYNAMIC SUPPORT IS IN ADDITION TO A
CONTRACTION IN THE WAVELENGTH OF THE UPPER LEVEL TROUGH.
CONCENTRATED DCVA IN COMBINATION WITH THE LOCALIZED
CONVERGENCE/NEAR SURFACE TROUGH AXIS WILL LEAD TO ENOUGH FORCING
TO SUPPORT LIGHT SNOW SHOWER ACTIVITY ACROSS MUCH OF THE AREA THIS
AFTERNOON. THE SUPERSATURATION WRT ICE SIGNAL IS GOOD ALONG WITH
THE STEEP LAPSE RATE POCKET ENCAPSULATING THE -15C ISOTHERM. A
LIGHT DUSTING...TO MINOR ACCUMULATIONS OF GENERALLY LESS THAN ONE
INCH WILL BE POSSIBLE FOR MUCH OF THE CWA TODAY. IT REMAINS
POSSIBLE FOR SNOWFALL ACCUMULATIONS OF AN INCH OR GREATER FOR THE
THUMB REGION.

LONG TERM...

CONTINUED DEEP NORTHERLY FLOW WILL START SATURDAY BEFORE THE LARGE
AREA OF COLD HIGH PRESSURE BECOMES CENTERED OVER LOWER MICHIGAN
DURING THE REST OF THE DAY. THE WIND DIRECTION FROM LAKE HURON INTO
THE THUMB WILL FAVOR LINGERING BUT DIMINISHING LAKE EFFECT
POTENTIAL. MODEL SOUNDINGS INDICATE NEAR DRY ADIABATIC LAPSE RATES
BUT ALSO SHOW CONVECTIVE DEPTH FORCED QUICKLY BELOW 850 MB/5000 FT.
THIS MAY BE GOOD FOR SOME FLURRIES BUT MORE LIKELY JUST SOME
STRATOCU WITHIN A SHALLOW LAYER OF SATURATION NEAR -15C THAT MIXES
OUT BY AFTERNOON. THE BUILDING SURFACE HIGH AND BACKING LOW LEVEL
WIND FIELD WILL NUDGE THE LOW LEVEL THERMAL TROUGH EASTWARD DURING
THE AFTERNOON. THIS...COMBINED WITH FULL LATE MARCH SUN...WILL HELP
MAX TEMPS RISE TOWARD THE MID 30S...BUT STILL A SOLID 15 DEGREES
BELOW NORMAL. THE STAGE WILL THEN BE SET FOR A COLD SATURDAY NIGHT
WITH MIN TEMPS LIKELY OCCURRING AROUND MIDNIGHT BEFORE HIGH CLOUDS
THICKEN AND SOUTHWEST WIND INCREASES OVERNIGHT THROUGH SUNRISE
SUNDAY.

THE HIGH CLOUDS SATURDAY NIGHT WILL BE THE FIRST SIGN OF THE NEXT
LOW PRESSURE SYSTEM ARRIVING IN THE GREAT LAKES. THIS SYSTEM IS
STILL OFFSHORE OVER THE GULF OF ALASKA AND WILL BE MOVING INLAND
TONIGHT BEFORE POWERING THROUGH THE LONG WAVE RIDGE OVER THE ROCKIES
DURING SATURDAY. THERE IS IMPROVED AGREEMENT IN THE 00Z MODEL RUNS
WITH RESPECT TO TIMING THE ARRIVAL OF PRECIPITATION WITH THIS SYSTEM
SUNDAY AFTERNOON IN SE MICHIGAN. THE MOISTURE PROFILE WILL BE A
HYBRID OF MID LEVEL PACIFIC AND LOW LEVEL GULF MODIFIED CONTINENTAL
WHICH IS SEEMS ADEQUATE FOR THE 0.1-0.2 MODEL QPF AND LIKELY POPS
SUNDAY AFTERNOON AND EVENING. THERE WILL BE SOME WET BULB COOLING
POTENTIAL AT ONSET BUT THE NAM IS GIVING IT TOO MUCH CREDIT FOR
COOLING THE BOUNDARY LAYER ENOUGH FOR SNOW IN THE MIDDLE OF THE DAY.
A PROFILE MORE LIKE THE GFS IS PREFERRED AND HELPS RULE OUT A
RAIN/SNOW MIX UNTIL SUNDAY NIGHT WHEN COLDER AIR SPILLS BACK INTO
THE REGION BEHIND THE SYSTEM.

GLOBAL MODELS MAINTAIN THE FRONTAL ZONE NEARBY TO START NEXT WEEK
WITH A COUPLE MORE LOW PREDICTABILITY SHORT WAVES TRAVERSING THE NW
FLOW ALOFT. EXPECT COLD AIR INTRUSIONS TO BE LESS HARSH COMPARED TO
THIS WEEKEND. AT THIS POINT...A STRONGER LOW PRESSURE SYSTEM IS
PROJECTED AROUND THE WEDNESDAY PERIOD THAT HAS POTENTIAL TO ALTER
THE LARGE SCALE PATTERN ENOUGH TO LIFT TEMPERATURES BACK TO NORMAL
FOR THE SECOND HALF OF NEXT WEEK.

MARINE...

STRONG NORTH WIND OVER LAKE HURON AND LOWER MICHIGAN WILL CARRY AIR
COLD ENOUGH FOR SNOW SHOWERS TODAY AND TONIGHT. GUSTS NEAR 30 KNOTS
WILL THEN EASE BACK DURING SATURDAY AS HIGH PRESSURE SETTLES
OVERHEAD. SOUTHWEST WIND WILL THEN RAMP UP SATURDAY NIGHT INTO
SUNDAY AS THE NEXT LOW PRESSURE SYSTEM MOVES INTO THE MIDWEST AND
WESTERN GREAT LAKES. SOUTHWEST GUSTS AROUND 25 KNOTS WILL BRING BACK
ENOUGH WARM AIR FOR MOSTLY RAIN SUNDAY AFTERNOON AND EVENING. COLDER
AIR WILL RETURN MONDAY BUT NOT AS COLD AS THIS WEEKEND.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

MI...NONE.

LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.

MICHIGAN WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....CB
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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




000
FXUS63 KDTX 271107
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
707 AM EDT FRI MAR 27 2015

.AVIATION...

A HIGH AMPLITUDE UPPER LEVEL TROUGH AND ASSOCIATED DEEP CYCLONIC
FLOW WILL KEEP MVFR TO LOWER VFR CIGS IN PLACE ACROSS ALL OF
SOUTHEASTERN MICHIGAN TODAY. FAVORABLE THERMODYNAMICS AND LOW
STABILITY IN THE LOWER PART OF THE ATMOSPHERE WILL SUPPORT SCATTERED
TO NUMEROUS SNOW SHOWERS AT THE TERMINALS FOR TODAY. TIMED SOME SNOW
SHOWERS ALONG A LOCALIZED SURFACE TROUGH AXIS THAT WILL SETTLE
SOUTHWARD THROUGH THE CWA DURING THE COURSE OF THE DAY. MAGNITUDE OF
THE DRY AIR AND STABLE MIDLEVEL PROFILE WILL LIMIT THE OVERALL
STRENGTH OF THE -SHSN ACTIVITY.

FOR DTW...FLURRIES ARE EXPECTED THIS MORNING. DAYTIME HEATING WILL
THEN ALLOW FOR A FAVORABLE ENVIRONMENT FOR FLARE UP IN SNOW SHOWER
ACTIVITY. CONFIDENCE REMAINS LOW IN OVERALL COVERAGE AND KEPT
DEGRADATION OF VSBY TO 6 MILES. MOST FAVORABLE TIMING AT DTW WILL BE
DURING THE AFTERNOON HOURS.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS AOB 5000 FT THROUGH MUCH OF THE FCST PERIOD.

&&

.PREV DISCUSSION...ISSUED 410 AM EDT FRI MAR 27 2015

SHORT TERM...TODAY AND TONIGHT

A FULL LATITUDE TROUGH OVER THE EASTERN CONTINENTAL UNITED STATES
WILL LEAD TO RAW CONDITIONS OVER SOUTHEASTERN MICHIGAN TODAY. THE
SPINE OF THE COLD AIR IS FORECASTED TO SETTLE INTO EASTERN LOWER
MICHIGAN BY 21Z THIS AFTERNOON. 850MB AND 925MB TEMPERATURES ARE
FORECASTED TO BE SOLIDLY OUTSIDE OF 1 SIGMA.  A STRAIGHT MIXING
TECHNIQUE SUPPORTS READINGS LIMITING OUT IN THE 20S. THE OUTGOING
FORECAST WILL SHADE A DEGREE OR TWO WARMER THAN THE AVAILABLE RAW
MODEL OUTPUT...MIDDLE 20S IN THE THUMB TO NEAR THE FREEZING MARK
ACROSS THE SOUTH...APPROXIMATELY 20 DEGREES BELOW NORMAL. A
SHARP...NORTH WIND WILL LEAD TO WINDCHILLS IN THE TEENS TO LOWER 20S
TODAY...AND IN THE LOWER SINGLE DIGITS TONIGHT.

WILL BE WATCHING A NUMBER OF THINGS FOR MORE ORGANIZED SNOW SHOWER
ACTIVITY TODAY. THE FIRST WILL BE ALONG A SURFACE CONVERGENCE
BOUNDARY ASSOCIATED WITH A WEST TO EAST SURFACE TROUGH AXIS THAT IS
FORECASTED TO PUSH SOUTHWARD THROUGH SOUTHEASTERN MICHIGAN DURING
THE COURSE OF THE ENTIRE DAY. RECENT RADAR IMAGERY FROM EXETER
ONTARIO SUGGESTS A FAIR AMOUNT OF REFLECTORS IN THE GENERAL LOCATION
OF THE AXIS THIS MORNING. HOWEVER...OVERSHOOTING OF THE RADAR BEAM
AT THESE DISTANCES LEADS TO A HIGH AMOUNT UNCERTAINTY. THE INHERITED
FORECAST STILL REMAINS VALID CALLING FOR SNOW SHOWERS
LIKELY/NUMEROUS IN THE THUMB THIS MORNING. AFTER THE MID TO LATE
MORNING ...FORECASTED LAPSE RATES SUPPORT A FLARE UP OF ACTIVITY
DUE TO THE DEEPENING OF THE BOUNDARY LAYER FROM DAYTIME HEATING.
PLAN VIEW EVOLUTION OF LL THETA E LAPSE RATES ALONG HIRES MODEL
OUTPUT SUGGESTS THIS POTENTIAL IS FOR ALL OF SOUTHEASTERN
MICHIGAN. THIS THERMODYNAMIC SUPPORT IS IN ADDITION TO A
CONTRACTION IN THE WAVELENGTH OF THE UPPER LEVEL TROUGH.
CONCENTRATED DCVA IN COMBINATION WITH THE LOCALIZED
CONVERGENCE/NEAR SURFACE TROUGH AXIS WILL LEAD TO ENOUGH FORCING
TO SUPPORT LIGHT SNOW SHOWER ACTIVITY ACROSS MUCH OF THE AREA THIS
AFTERNOON. THE SUPERSATURATION WRT ICE SIGNAL IS GOOD ALONG WITH
THE STEEP LAPSE RATE POCKET ENCAPSULATING THE -15C ISOTHERM. A
LIGHT DUSTING...TO MINOR ACCUMULATIONS OF GENERALLY LESS THAN ONE
INCH WILL BE POSSIBLE FOR MUCH OF THE CWA TODAY. IT REMAINS
POSSIBLE FOR SNOWFALL ACCUMULATIONS OF AN INCH OR GREATER FOR THE
THUMB REGION.

LONG TERM...

CONTINUED DEEP NORTHERLY FLOW WILL START SATURDAY BEFORE THE LARGE
AREA OF COLD HIGH PRESSURE BECOMES CENTERED OVER LOWER MICHIGAN
DURING THE REST OF THE DAY. THE WIND DIRECTION FROM LAKE HURON INTO
THE THUMB WILL FAVOR LINGERING BUT DIMINISHING LAKE EFFECT
POTENTIAL. MODEL SOUNDINGS INDICATE NEAR DRY ADIABATIC LAPSE RATES
BUT ALSO SHOW CONVECTIVE DEPTH FORCED QUICKLY BELOW 850 MB/5000 FT.
THIS MAY BE GOOD FOR SOME FLURRIES BUT MORE LIKELY JUST SOME
STRATOCU WITHIN A SHALLOW LAYER OF SATURATION NEAR -15C THAT MIXES
OUT BY AFTERNOON. THE BUILDING SURFACE HIGH AND BACKING LOW LEVEL
WIND FIELD WILL NUDGE THE LOW LEVEL THERMAL TROUGH EASTWARD DURING
THE AFTERNOON. THIS...COMBINED WITH FULL LATE MARCH SUN...WILL HELP
MAX TEMPS RISE TOWARD THE MID 30S...BUT STILL A SOLID 15 DEGREES
BELOW NORMAL. THE STAGE WILL THEN BE SET FOR A COLD SATURDAY NIGHT
WITH MIN TEMPS LIKELY OCCURRING AROUND MIDNIGHT BEFORE HIGH CLOUDS
THICKEN AND SOUTHWEST WIND INCREASES OVERNIGHT THROUGH SUNRISE
SUNDAY.

THE HIGH CLOUDS SATURDAY NIGHT WILL BE THE FIRST SIGN OF THE NEXT
LOW PRESSURE SYSTEM ARRIVING IN THE GREAT LAKES. THIS SYSTEM IS
STILL OFFSHORE OVER THE GULF OF ALASKA AND WILL BE MOVING INLAND
TONIGHT BEFORE POWERING THROUGH THE LONG WAVE RIDGE OVER THE ROCKIES
DURING SATURDAY. THERE IS IMPROVED AGREEMENT IN THE 00Z MODEL RUNS
WITH RESPECT TO TIMING THE ARRIVAL OF PRECIPITATION WITH THIS SYSTEM
SUNDAY AFTERNOON IN SE MICHIGAN. THE MOISTURE PROFILE WILL BE A
HYBRID OF MID LEVEL PACIFIC AND LOW LEVEL GULF MODIFIED CONTINENTAL
WHICH IS SEEMS ADEQUATE FOR THE 0.1-0.2 MODEL QPF AND LIKELY POPS
SUNDAY AFTERNOON AND EVENING. THERE WILL BE SOME WET BULB COOLING
POTENTIAL AT ONSET BUT THE NAM IS GIVING IT TOO MUCH CREDIT FOR
COOLING THE BOUNDARY LAYER ENOUGH FOR SNOW IN THE MIDDLE OF THE DAY.
A PROFILE MORE LIKE THE GFS IS PREFERRED AND HELPS RULE OUT A
RAIN/SNOW MIX UNTIL SUNDAY NIGHT WHEN COLDER AIR SPILLS BACK INTO
THE REGION BEHIND THE SYSTEM.

GLOBAL MODELS MAINTAIN THE FRONTAL ZONE NEARBY TO START NEXT WEEK
WITH A COUPLE MORE LOW PREDICTABILITY SHORT WAVES TRAVERSING THE NW
FLOW ALOFT. EXPECT COLD AIR INTRUSIONS TO BE LESS HARSH COMPARED TO
THIS WEEKEND. AT THIS POINT...A STRONGER LOW PRESSURE SYSTEM IS
PROJECTED AROUND THE WEDNESDAY PERIOD THAT HAS POTENTIAL TO ALTER
THE LARGE SCALE PATTERN ENOUGH TO LIFT TEMPERATURES BACK TO NORMAL
FOR THE SECOND HALF OF NEXT WEEK.

MARINE...

STRONG NORTH WIND OVER LAKE HURON AND LOWER MICHIGAN WILL CARRY AIR
COLD ENOUGH FOR SNOW SHOWERS TODAY AND TONIGHT. GUSTS NEAR 30 KNOTS
WILL THEN EASE BACK DURING SATURDAY AS HIGH PRESSURE SETTLES
OVERHEAD. SOUTHWEST WIND WILL THEN RAMP UP SATURDAY NIGHT INTO
SUNDAY AS THE NEXT LOW PRESSURE SYSTEM MOVES INTO THE MIDWEST AND
WESTERN GREAT LAKES. SOUTHWEST GUSTS AROUND 25 KNOTS WILL BRING BACK
ENOUGH WARM AIR FOR MOSTLY RAIN SUNDAY AFTERNOON AND EVENING. COLDER
AIR WILL RETURN MONDAY BUT NOT AS COLD AS THIS WEEKEND.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

MI...NONE.

LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.

MICHIGAN WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....CB
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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




000
FXUS63 KDTX 271107
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
707 AM EDT FRI MAR 27 2015

.AVIATION...

A HIGH AMPLITUDE UPPER LEVEL TROUGH AND ASSOCIATED DEEP CYCLONIC
FLOW WILL KEEP MVFR TO LOWER VFR CIGS IN PLACE ACROSS ALL OF
SOUTHEASTERN MICHIGAN TODAY. FAVORABLE THERMODYNAMICS AND LOW
STABILITY IN THE LOWER PART OF THE ATMOSPHERE WILL SUPPORT SCATTERED
TO NUMEROUS SNOW SHOWERS AT THE TERMINALS FOR TODAY. TIMED SOME SNOW
SHOWERS ALONG A LOCALIZED SURFACE TROUGH AXIS THAT WILL SETTLE
SOUTHWARD THROUGH THE CWA DURING THE COURSE OF THE DAY. MAGNITUDE OF
THE DRY AIR AND STABLE MIDLEVEL PROFILE WILL LIMIT THE OVERALL
STRENGTH OF THE -SHSN ACTIVITY.

FOR DTW...FLURRIES ARE EXPECTED THIS MORNING. DAYTIME HEATING WILL
THEN ALLOW FOR A FAVORABLE ENVIRONMENT FOR FLARE UP IN SNOW SHOWER
ACTIVITY. CONFIDENCE REMAINS LOW IN OVERALL COVERAGE AND KEPT
DEGRADATION OF VSBY TO 6 MILES. MOST FAVORABLE TIMING AT DTW WILL BE
DURING THE AFTERNOON HOURS.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS AOB 5000 FT THROUGH MUCH OF THE FCST PERIOD.

&&

.PREV DISCUSSION...ISSUED 410 AM EDT FRI MAR 27 2015

SHORT TERM...TODAY AND TONIGHT

A FULL LATITUDE TROUGH OVER THE EASTERN CONTINENTAL UNITED STATES
WILL LEAD TO RAW CONDITIONS OVER SOUTHEASTERN MICHIGAN TODAY. THE
SPINE OF THE COLD AIR IS FORECASTED TO SETTLE INTO EASTERN LOWER
MICHIGAN BY 21Z THIS AFTERNOON. 850MB AND 925MB TEMPERATURES ARE
FORECASTED TO BE SOLIDLY OUTSIDE OF 1 SIGMA.  A STRAIGHT MIXING
TECHNIQUE SUPPORTS READINGS LIMITING OUT IN THE 20S. THE OUTGOING
FORECAST WILL SHADE A DEGREE OR TWO WARMER THAN THE AVAILABLE RAW
MODEL OUTPUT...MIDDLE 20S IN THE THUMB TO NEAR THE FREEZING MARK
ACROSS THE SOUTH...APPROXIMATELY 20 DEGREES BELOW NORMAL. A
SHARP...NORTH WIND WILL LEAD TO WINDCHILLS IN THE TEENS TO LOWER 20S
TODAY...AND IN THE LOWER SINGLE DIGITS TONIGHT.

WILL BE WATCHING A NUMBER OF THINGS FOR MORE ORGANIZED SNOW SHOWER
ACTIVITY TODAY. THE FIRST WILL BE ALONG A SURFACE CONVERGENCE
BOUNDARY ASSOCIATED WITH A WEST TO EAST SURFACE TROUGH AXIS THAT IS
FORECASTED TO PUSH SOUTHWARD THROUGH SOUTHEASTERN MICHIGAN DURING
THE COURSE OF THE ENTIRE DAY. RECENT RADAR IMAGERY FROM EXETER
ONTARIO SUGGESTS A FAIR AMOUNT OF REFLECTORS IN THE GENERAL LOCATION
OF THE AXIS THIS MORNING. HOWEVER...OVERSHOOTING OF THE RADAR BEAM
AT THESE DISTANCES LEADS TO A HIGH AMOUNT UNCERTAINTY. THE INHERITED
FORECAST STILL REMAINS VALID CALLING FOR SNOW SHOWERS
LIKELY/NUMEROUS IN THE THUMB THIS MORNING. AFTER THE MID TO LATE
MORNING ...FORECASTED LAPSE RATES SUPPORT A FLARE UP OF ACTIVITY
DUE TO THE DEEPENING OF THE BOUNDARY LAYER FROM DAYTIME HEATING.
PLAN VIEW EVOLUTION OF LL THETA E LAPSE RATES ALONG HIRES MODEL
OUTPUT SUGGESTS THIS POTENTIAL IS FOR ALL OF SOUTHEASTERN
MICHIGAN. THIS THERMODYNAMIC SUPPORT IS IN ADDITION TO A
CONTRACTION IN THE WAVELENGTH OF THE UPPER LEVEL TROUGH.
CONCENTRATED DCVA IN COMBINATION WITH THE LOCALIZED
CONVERGENCE/NEAR SURFACE TROUGH AXIS WILL LEAD TO ENOUGH FORCING
TO SUPPORT LIGHT SNOW SHOWER ACTIVITY ACROSS MUCH OF THE AREA THIS
AFTERNOON. THE SUPERSATURATION WRT ICE SIGNAL IS GOOD ALONG WITH
THE STEEP LAPSE RATE POCKET ENCAPSULATING THE -15C ISOTHERM. A
LIGHT DUSTING...TO MINOR ACCUMULATIONS OF GENERALLY LESS THAN ONE
INCH WILL BE POSSIBLE FOR MUCH OF THE CWA TODAY. IT REMAINS
POSSIBLE FOR SNOWFALL ACCUMULATIONS OF AN INCH OR GREATER FOR THE
THUMB REGION.

LONG TERM...

CONTINUED DEEP NORTHERLY FLOW WILL START SATURDAY BEFORE THE LARGE
AREA OF COLD HIGH PRESSURE BECOMES CENTERED OVER LOWER MICHIGAN
DURING THE REST OF THE DAY. THE WIND DIRECTION FROM LAKE HURON INTO
THE THUMB WILL FAVOR LINGERING BUT DIMINISHING LAKE EFFECT
POTENTIAL. MODEL SOUNDINGS INDICATE NEAR DRY ADIABATIC LAPSE RATES
BUT ALSO SHOW CONVECTIVE DEPTH FORCED QUICKLY BELOW 850 MB/5000 FT.
THIS MAY BE GOOD FOR SOME FLURRIES BUT MORE LIKELY JUST SOME
STRATOCU WITHIN A SHALLOW LAYER OF SATURATION NEAR -15C THAT MIXES
OUT BY AFTERNOON. THE BUILDING SURFACE HIGH AND BACKING LOW LEVEL
WIND FIELD WILL NUDGE THE LOW LEVEL THERMAL TROUGH EASTWARD DURING
THE AFTERNOON. THIS...COMBINED WITH FULL LATE MARCH SUN...WILL HELP
MAX TEMPS RISE TOWARD THE MID 30S...BUT STILL A SOLID 15 DEGREES
BELOW NORMAL. THE STAGE WILL THEN BE SET FOR A COLD SATURDAY NIGHT
WITH MIN TEMPS LIKELY OCCURRING AROUND MIDNIGHT BEFORE HIGH CLOUDS
THICKEN AND SOUTHWEST WIND INCREASES OVERNIGHT THROUGH SUNRISE
SUNDAY.

THE HIGH CLOUDS SATURDAY NIGHT WILL BE THE FIRST SIGN OF THE NEXT
LOW PRESSURE SYSTEM ARRIVING IN THE GREAT LAKES. THIS SYSTEM IS
STILL OFFSHORE OVER THE GULF OF ALASKA AND WILL BE MOVING INLAND
TONIGHT BEFORE POWERING THROUGH THE LONG WAVE RIDGE OVER THE ROCKIES
DURING SATURDAY. THERE IS IMPROVED AGREEMENT IN THE 00Z MODEL RUNS
WITH RESPECT TO TIMING THE ARRIVAL OF PRECIPITATION WITH THIS SYSTEM
SUNDAY AFTERNOON IN SE MICHIGAN. THE MOISTURE PROFILE WILL BE A
HYBRID OF MID LEVEL PACIFIC AND LOW LEVEL GULF MODIFIED CONTINENTAL
WHICH IS SEEMS ADEQUATE FOR THE 0.1-0.2 MODEL QPF AND LIKELY POPS
SUNDAY AFTERNOON AND EVENING. THERE WILL BE SOME WET BULB COOLING
POTENTIAL AT ONSET BUT THE NAM IS GIVING IT TOO MUCH CREDIT FOR
COOLING THE BOUNDARY LAYER ENOUGH FOR SNOW IN THE MIDDLE OF THE DAY.
A PROFILE MORE LIKE THE GFS IS PREFERRED AND HELPS RULE OUT A
RAIN/SNOW MIX UNTIL SUNDAY NIGHT WHEN COLDER AIR SPILLS BACK INTO
THE REGION BEHIND THE SYSTEM.

GLOBAL MODELS MAINTAIN THE FRONTAL ZONE NEARBY TO START NEXT WEEK
WITH A COUPLE MORE LOW PREDICTABILITY SHORT WAVES TRAVERSING THE NW
FLOW ALOFT. EXPECT COLD AIR INTRUSIONS TO BE LESS HARSH COMPARED TO
THIS WEEKEND. AT THIS POINT...A STRONGER LOW PRESSURE SYSTEM IS
PROJECTED AROUND THE WEDNESDAY PERIOD THAT HAS POTENTIAL TO ALTER
THE LARGE SCALE PATTERN ENOUGH TO LIFT TEMPERATURES BACK TO NORMAL
FOR THE SECOND HALF OF NEXT WEEK.

MARINE...

STRONG NORTH WIND OVER LAKE HURON AND LOWER MICHIGAN WILL CARRY AIR
COLD ENOUGH FOR SNOW SHOWERS TODAY AND TONIGHT. GUSTS NEAR 30 KNOTS
WILL THEN EASE BACK DURING SATURDAY AS HIGH PRESSURE SETTLES
OVERHEAD. SOUTHWEST WIND WILL THEN RAMP UP SATURDAY NIGHT INTO
SUNDAY AS THE NEXT LOW PRESSURE SYSTEM MOVES INTO THE MIDWEST AND
WESTERN GREAT LAKES. SOUTHWEST GUSTS AROUND 25 KNOTS WILL BRING BACK
ENOUGH WARM AIR FOR MOSTLY RAIN SUNDAY AFTERNOON AND EVENING. COLDER
AIR WILL RETURN MONDAY BUT NOT AS COLD AS THIS WEEKEND.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...

MI...NONE.

LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.

MICHIGAN WATERS OF LAKE ERIE...NONE.

&&

$$

AVIATION.....CB
SHORT TERM...CB
LONG TERM....BT
MARINE.......BT


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





000
FXUS63 KDTX 270810
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
410 AM EDT FRI MAR 27 2015

.SHORT TERM...TODAY AND TONIGHT

A FULL LATITUDE TROUGH OVER THE EASTERN CONTINENTAL UNITED STATES
WILL LEAD TO RAW CONDITIONS OVER SOUTHEASTERN MICHIGAN TODAY. THE
SPINE OF THE COLD AIR IS FORECASTED TO SETTLE INTO EASTERN LOWER
MICHIGAN BY 21Z THIS AFTERNOON. 850MB AND 925MB TEMPERATURES ARE
FORECASTED TO BE SOLIDLY OUTSIDE OF 1 SIGMA.  A STRAIGHT MIXING
TECHNIQUE SUPPORTS READINGS LIMITING OUT IN THE 20S. THE OUTGOING
FORECAST WILL SHADE A DEGREE OR TWO WARMER THAN THE AVAILABLE RAW
MODEL OUTPUT...MIDDLE 20S IN THE THUMB TO NEAR THE FREEZING MARK
ACROSS THE SOUTH...APPROXIMATELY 20 DEGREES BELOW NORMAL. A
SHARP...NORTH WIND WILL LEAD TO WINDCHILLS IN THE TEENS TO LOWER 20S
TODAY...AND IN THE LOWER SINGLE DIGITS TONIGHT.

WILL BE WATCHING A NUMBER OF THINGS FOR MORE ORGANIZED SNOW SHOWER
ACTIVITY TODAY. THE FIRST WILL BE ALONG A SURFACE CONVERGENCE
BOUNDARY ASSOCIATED WITH A WEST TO EAST SURFACE TROUGH AXIS THAT IS
FORECASTED TO PUSH SOUTHWARD THROUGH SOUTHEASTERN MICHIGAN DURING
THE COURSE OF THE ENTIRE DAY. RECENT RADAR IMAGERY FROM EXETER
ONTARIO SUGGESTS A FAIR AMOUNT OF REFLECTORS IN THE GENERAL LOCATION
OF THE AXIS THIS MORNING. HOWEVER...OVERSHOOTING OF THE RADAR BEAM
AT THESE DISTANCES LEADS TO A HIGH AMOUNT UNCERTAINTY. THE INHERITED
FORECAST STILL REMAINS VALID CALLING FOR SNOW SHOWERS
LIKELY/NUMEROUS IN THE THUMB THIS MORNING. AFTER THE MID TO LATE
MORNING ...FORECASTED LAPSE RATES SUPPORT A FLARE UP OF ACTIVITY
DUE TO THE DEEPENING OF THE BOUNDARY LAYER FROM DAYTIME HEATING.
PLAN VIEW EVOLUTION OF LL THETA E LAPSE RATES ALONG HIRES MODEL
OUTPUT SUGGESTS THIS POTENTIAL IS FOR ALL OF SOUTHEASTERN
MICHIGAN. THIS THERMODYNAMIC SUPPORT IS IN ADDTION TO A
CONTRACTION IN THE WAVELENGTH OF THE UPPER LEVEL TROUGH.
CONCENTRATED DCVA IN COMBINATION WITH THE LOCALIZED
CONVERGENCE/NEAR SURFACE TROUGH AXIS WILL LEAD TO ENOUGH FORCING
TO SUPPORT LIGHT SNOW SHOWER ACTIVITY ACROSS MUCH OF THE AREA THIS
AFTERNOON. THE SUPERSATURATION WRT ICE SIGNAL IS GOOD ALONG WITH
THE STEEP LAPSE RATE POCKET ENCAPSULATING THE -15C ISOTHERM. A
LIGHT DUSTING...TO MINOR ACCUMULATIONS OF GENERALLY LESS THAN ONE
INCH WILL BE POSSIBLE FOR MUCH OF THE CWA TODAY. IT REMAINS
POSSIBLE FOR SNOWFALL ACCUMLATIONS OF AN INCH OR GREATER FOR THE
THUMB REGION.

&&

.LONG TERM...

CONTINUED DEEP NORTHERLY FLOW WILL START SATURDAY BEFORE THE LARGE
AREA OF COLD HIGH PRESSURE BECOMES CENTERED OVER LOWER MICHIGAN
DURING THE REST OF THE DAY. THE WIND DIRECTION FROM LAKE HURON INTO
THE THUMB WILL FAVOR LINGERING BUT DIMINISHING LAKE EFFECT
POTENTIAL. MODEL SOUNDINGS INDICATE NEAR DRY ADIABATIC LAPSE RATES
BUT ALSO SHOW CONVECTIVE DEPTH FORCED QUICKLY BELOW 850 MB/5000 FT.
THIS MAY BE GOOD FOR SOME FLURRIES BUT MORE LIKELY JUST SOME
STRATOCU WITHIN A SHALLOW LAYER OF SATURATION NEAR -15C THAT MIXES
OUT BY AFTERNOON. THE BUILDING SURFACE HIGH AND BACKING LOW LEVEL
WIND FIELD WILL NUDGE THE LOW LEVEL THERMAL TROUGH EASTWARD DURING
THE AFTERNOON. THIS...COMBINED WITH FULL LATE MARCH SUN...WILL HELP
MAX TEMPS RISE TOWARD THE MID 30S...BUT STILL A SOLID 15 DEGREES
BELOW NORMAL. THE STAGE WILL THEN BE SET FOR A COLD SATURDAY NIGHT
WITH MIN TEMPS LIKELY OCCURRING AROUND MIDNIGHT BEFORE HIGH CLOUDS
THICKEN AND SOUTHWEST WIND INCREASES OVERNIGHT THROUGH SUNRISE
SUNDAY.

THE HIGH CLOUDS SATURDAY NIGHT WILL BE THE FIRST SIGN OF THE NEXT
LOW PRESSURE SYSTEM ARRIVING IN THE GREAT LAKES. THIS SYSTEM IS
STILL OFFSHORE OVER THE GULF OF ALASKA AND WILL BE MOVING INLAND
TONIGHT BEFORE POWERING THROUGH THE LONG WAVE RIDGE OVER THE ROCKIES
DURING SATURDAY. THERE IS IMPROVED AGREEMENT IN THE 00Z MODEL RUNS
WITH RESPECT TO TIMING THE ARRIVAL OF PRECIPITATION WITH THIS SYSTEM
SUNDAY AFTERNOON IN SE MICHIGAN. THE MOISTURE PROFILE WILL BE A
HYBRID OF MID LEVEL PACIFIC AND LOW LEVEL GULF MODIFIED CONTINENTAL
WHICH IS SEEMS ADEQUATE FOR THE 0.1-0.2 MODEL QPF AND LIKELY POPS
SUNDAY AFTERNOON AND EVENING. THERE WILL BE SOME WET BULB COOLING
POTENTIAL AT ONSET BUT THE NAM IS GIVING IT TOO MUCH CREDIT FOR
COOLING THE BOUNDARY LAYER ENOUGH FOR SNOW IN THE MIDDLE OF THE DAY.
A PROFILE MORE LIKE THE GFS IS PREFERRED AND HELPS RULE OUT A
RAIN/SNOW MIX UNTIL SUNDAY NIGHT WHEN COLDER AIR SPILLS BACK INTO
THE REGION BEHIND THE SYSTEM.

GLOBAL MODELS MAINTAIN THE FRONTAL ZONE NEARBY TO START NEXT WEEK
WITH A COUPLE MORE LOW PREDICTABILITY SHORT WAVES TRAVERSING THE NW
FLOW ALOFT. EXPECT COLD AIR INTRUSIONS TO BE LESS HARSH COMPARED TO
THIS WEEKEND. AT THIS POINT...A STRONGER LOW PRESSURE SYSTEM IS
PROJECTED AROUND THE WEDNESDAY PERIOD THAT HAS POTENTIAL TO ALTER
THE LARGE SCALE PATTERN ENOUGH TO LIFT TEMPERATURES BACK TO NORMAL
FOR THE SECOND HALF OF NEXT WEEK.

&&

.MARINE...

STRONG NORTH WIND OVER LAKE HURON AND LOWER MICHIGAN WILL CARRY AIR
COLD ENOUGH FOR SNOW SHOWERS TODAY AND TONIGHT. GUSTS NEAR 30 KNOTS
WILL THEN EASE BACK DURING SATURDAY AS HIGH PRESSURE SETTLES
OVERHEAD. SOUTHWEST WIND WILL THEN RAMP UP SATURDAY NIGHT INTO
SUNDAY AS THE NEXT LOW PRESSURE SYSTEM MOVES INTO THE MIDWEST AND
WESTERN GREAT LAKES. SOUTHWEST GUSTS AROUND 25 KNOTS WILL BRING BACK
ENOUGH WARM AIR FOR MOSTLY RAIN SUNDAY AFTERNOON AND EVENING. COLDER
AIR WILL RETURN MONDAY BUT NOT AS COLD AS THIS WEEKEND.

&&

.AVIATION...ISSUED 1159 PM EDT THU MAR 26 2015

MVFR TO LOWER VFR DECK IN THE 3-5KFT RANGE WILL BE PERSIST INTO
FRIDAY WITHIN COLD...CYCLONIC NORTHWEST FLOW. CIGS WILL TEND TO BE
LOWEST FROM KPTK NORTHWARD DURING THIS FORECAST PERIOD. WHILE A FEW
SCATTERED -SHSNS WILL DOT THE AREA THROUGHOUT THE FORECAST...THESE
SHOULD NOT IMPACT THE TERMINALS IN ANY NOTABLE WAY. NORTHWEST FLOW
WILL VEER TO THE NORTH WITH THE PASSAGE OF A TROUGH LATE TONIGHT
INTO FRIDAY.

FOR DTW...CIGS WILL BE NEAR 5KFT MUCH OF THE FORECAST PERIOD WITH
JUST A FEW BREAKS POSSIBLE LATE TONIGHT/EARLY FRIDAY. TRUE CLEARING
WILL THEN OCCUR LATE IN THE FORECAST PERIOD...POST 00Z FRIDAY...AS
HIGH PRESSURE BEGINS TO NOSE INTO THE AREA. WNW WINDS WILL VEER TO
NORTH THEN NNE...AND REMAIN NEAR 10 KNOTS MUCH OF THE TIME.


//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS AOB 5000 FT THROUGH MUCH OF THE FCST PERIOD.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

SHORT TERM...CB
LONG TERM....BT
MARINE.......BT
AVIATION.....DG


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





000
FXUS63 KDTX 270810
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
410 AM EDT FRI MAR 27 2015

.SHORT TERM...TODAY AND TONIGHT

A FULL LATITUDE TROUGH OVER THE EASTERN CONTINENTAL UNITED STATES
WILL LEAD TO RAW CONDITIONS OVER SOUTHEASTERN MICHIGAN TODAY. THE
SPINE OF THE COLD AIR IS FORECASTED TO SETTLE INTO EASTERN LOWER
MICHIGAN BY 21Z THIS AFTERNOON. 850MB AND 925MB TEMPERATURES ARE
FORECASTED TO BE SOLIDLY OUTSIDE OF 1 SIGMA.  A STRAIGHT MIXING
TECHNIQUE SUPPORTS READINGS LIMITING OUT IN THE 20S. THE OUTGOING
FORECAST WILL SHADE A DEGREE OR TWO WARMER THAN THE AVAILABLE RAW
MODEL OUTPUT...MIDDLE 20S IN THE THUMB TO NEAR THE FREEZING MARK
ACROSS THE SOUTH...APPROXIMATELY 20 DEGREES BELOW NORMAL. A
SHARP...NORTH WIND WILL LEAD TO WINDCHILLS IN THE TEENS TO LOWER 20S
TODAY...AND IN THE LOWER SINGLE DIGITS TONIGHT.

WILL BE WATCHING A NUMBER OF THINGS FOR MORE ORGANIZED SNOW SHOWER
ACTIVITY TODAY. THE FIRST WILL BE ALONG A SURFACE CONVERGENCE
BOUNDARY ASSOCIATED WITH A WEST TO EAST SURFACE TROUGH AXIS THAT IS
FORECASTED TO PUSH SOUTHWARD THROUGH SOUTHEASTERN MICHIGAN DURING
THE COURSE OF THE ENTIRE DAY. RECENT RADAR IMAGERY FROM EXETER
ONTARIO SUGGESTS A FAIR AMOUNT OF REFLECTORS IN THE GENERAL LOCATION
OF THE AXIS THIS MORNING. HOWEVER...OVERSHOOTING OF THE RADAR BEAM
AT THESE DISTANCES LEADS TO A HIGH AMOUNT UNCERTAINTY. THE INHERITED
FORECAST STILL REMAINS VALID CALLING FOR SNOW SHOWERS
LIKELY/NUMEROUS IN THE THUMB THIS MORNING. AFTER THE MID TO LATE
MORNING ...FORECASTED LAPSE RATES SUPPORT A FLARE UP OF ACTIVITY
DUE TO THE DEEPENING OF THE BOUNDARY LAYER FROM DAYTIME HEATING.
PLAN VIEW EVOLUTION OF LL THETA E LAPSE RATES ALONG HIRES MODEL
OUTPUT SUGGESTS THIS POTENTIAL IS FOR ALL OF SOUTHEASTERN
MICHIGAN. THIS THERMODYNAMIC SUPPORT IS IN ADDTION TO A
CONTRACTION IN THE WAVELENGTH OF THE UPPER LEVEL TROUGH.
CONCENTRATED DCVA IN COMBINATION WITH THE LOCALIZED
CONVERGENCE/NEAR SURFACE TROUGH AXIS WILL LEAD TO ENOUGH FORCING
TO SUPPORT LIGHT SNOW SHOWER ACTIVITY ACROSS MUCH OF THE AREA THIS
AFTERNOON. THE SUPERSATURATION WRT ICE SIGNAL IS GOOD ALONG WITH
THE STEEP LAPSE RATE POCKET ENCAPSULATING THE -15C ISOTHERM. A
LIGHT DUSTING...TO MINOR ACCUMULATIONS OF GENERALLY LESS THAN ONE
INCH WILL BE POSSIBLE FOR MUCH OF THE CWA TODAY. IT REMAINS
POSSIBLE FOR SNOWFALL ACCUMLATIONS OF AN INCH OR GREATER FOR THE
THUMB REGION.

&&

.LONG TERM...

CONTINUED DEEP NORTHERLY FLOW WILL START SATURDAY BEFORE THE LARGE
AREA OF COLD HIGH PRESSURE BECOMES CENTERED OVER LOWER MICHIGAN
DURING THE REST OF THE DAY. THE WIND DIRECTION FROM LAKE HURON INTO
THE THUMB WILL FAVOR LINGERING BUT DIMINISHING LAKE EFFECT
POTENTIAL. MODEL SOUNDINGS INDICATE NEAR DRY ADIABATIC LAPSE RATES
BUT ALSO SHOW CONVECTIVE DEPTH FORCED QUICKLY BELOW 850 MB/5000 FT.
THIS MAY BE GOOD FOR SOME FLURRIES BUT MORE LIKELY JUST SOME
STRATOCU WITHIN A SHALLOW LAYER OF SATURATION NEAR -15C THAT MIXES
OUT BY AFTERNOON. THE BUILDING SURFACE HIGH AND BACKING LOW LEVEL
WIND FIELD WILL NUDGE THE LOW LEVEL THERMAL TROUGH EASTWARD DURING
THE AFTERNOON. THIS...COMBINED WITH FULL LATE MARCH SUN...WILL HELP
MAX TEMPS RISE TOWARD THE MID 30S...BUT STILL A SOLID 15 DEGREES
BELOW NORMAL. THE STAGE WILL THEN BE SET FOR A COLD SATURDAY NIGHT
WITH MIN TEMPS LIKELY OCCURRING AROUND MIDNIGHT BEFORE HIGH CLOUDS
THICKEN AND SOUTHWEST WIND INCREASES OVERNIGHT THROUGH SUNRISE
SUNDAY.

THE HIGH CLOUDS SATURDAY NIGHT WILL BE THE FIRST SIGN OF THE NEXT
LOW PRESSURE SYSTEM ARRIVING IN THE GREAT LAKES. THIS SYSTEM IS
STILL OFFSHORE OVER THE GULF OF ALASKA AND WILL BE MOVING INLAND
TONIGHT BEFORE POWERING THROUGH THE LONG WAVE RIDGE OVER THE ROCKIES
DURING SATURDAY. THERE IS IMPROVED AGREEMENT IN THE 00Z MODEL RUNS
WITH RESPECT TO TIMING THE ARRIVAL OF PRECIPITATION WITH THIS SYSTEM
SUNDAY AFTERNOON IN SE MICHIGAN. THE MOISTURE PROFILE WILL BE A
HYBRID OF MID LEVEL PACIFIC AND LOW LEVEL GULF MODIFIED CONTINENTAL
WHICH IS SEEMS ADEQUATE FOR THE 0.1-0.2 MODEL QPF AND LIKELY POPS
SUNDAY AFTERNOON AND EVENING. THERE WILL BE SOME WET BULB COOLING
POTENTIAL AT ONSET BUT THE NAM IS GIVING IT TOO MUCH CREDIT FOR
COOLING THE BOUNDARY LAYER ENOUGH FOR SNOW IN THE MIDDLE OF THE DAY.
A PROFILE MORE LIKE THE GFS IS PREFERRED AND HELPS RULE OUT A
RAIN/SNOW MIX UNTIL SUNDAY NIGHT WHEN COLDER AIR SPILLS BACK INTO
THE REGION BEHIND THE SYSTEM.

GLOBAL MODELS MAINTAIN THE FRONTAL ZONE NEARBY TO START NEXT WEEK
WITH A COUPLE MORE LOW PREDICTABILITY SHORT WAVES TRAVERSING THE NW
FLOW ALOFT. EXPECT COLD AIR INTRUSIONS TO BE LESS HARSH COMPARED TO
THIS WEEKEND. AT THIS POINT...A STRONGER LOW PRESSURE SYSTEM IS
PROJECTED AROUND THE WEDNESDAY PERIOD THAT HAS POTENTIAL TO ALTER
THE LARGE SCALE PATTERN ENOUGH TO LIFT TEMPERATURES BACK TO NORMAL
FOR THE SECOND HALF OF NEXT WEEK.

&&

.MARINE...

STRONG NORTH WIND OVER LAKE HURON AND LOWER MICHIGAN WILL CARRY AIR
COLD ENOUGH FOR SNOW SHOWERS TODAY AND TONIGHT. GUSTS NEAR 30 KNOTS
WILL THEN EASE BACK DURING SATURDAY AS HIGH PRESSURE SETTLES
OVERHEAD. SOUTHWEST WIND WILL THEN RAMP UP SATURDAY NIGHT INTO
SUNDAY AS THE NEXT LOW PRESSURE SYSTEM MOVES INTO THE MIDWEST AND
WESTERN GREAT LAKES. SOUTHWEST GUSTS AROUND 25 KNOTS WILL BRING BACK
ENOUGH WARM AIR FOR MOSTLY RAIN SUNDAY AFTERNOON AND EVENING. COLDER
AIR WILL RETURN MONDAY BUT NOT AS COLD AS THIS WEEKEND.

&&

.AVIATION...ISSUED 1159 PM EDT THU MAR 26 2015

MVFR TO LOWER VFR DECK IN THE 3-5KFT RANGE WILL BE PERSIST INTO
FRIDAY WITHIN COLD...CYCLONIC NORTHWEST FLOW. CIGS WILL TEND TO BE
LOWEST FROM KPTK NORTHWARD DURING THIS FORECAST PERIOD. WHILE A FEW
SCATTERED -SHSNS WILL DOT THE AREA THROUGHOUT THE FORECAST...THESE
SHOULD NOT IMPACT THE TERMINALS IN ANY NOTABLE WAY. NORTHWEST FLOW
WILL VEER TO THE NORTH WITH THE PASSAGE OF A TROUGH LATE TONIGHT
INTO FRIDAY.

FOR DTW...CIGS WILL BE NEAR 5KFT MUCH OF THE FORECAST PERIOD WITH
JUST A FEW BREAKS POSSIBLE LATE TONIGHT/EARLY FRIDAY. TRUE CLEARING
WILL THEN OCCUR LATE IN THE FORECAST PERIOD...POST 00Z FRIDAY...AS
HIGH PRESSURE BEGINS TO NOSE INTO THE AREA. WNW WINDS WILL VEER TO
NORTH THEN NNE...AND REMAIN NEAR 10 KNOTS MUCH OF THE TIME.


//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS AOB 5000 FT THROUGH MUCH OF THE FCST PERIOD.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

SHORT TERM...CB
LONG TERM....BT
MARINE.......BT
AVIATION.....DG


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




000
FXUS63 KDTX 270359
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1159 PM EDT THU MAR 26 2015


.AVIATION...

MVFR TO LOWER VFR DECK IN THE 3-5KFT RANGE WILL BE PERSIST INTO
FRIDAY WITHIN COLD...CYCLONIC NORTHWEST FLOW. CIGS WILL TEND TO BE
LOWEST FROM KPTK NORTHWARD DURING THIS FORECAST PERIOD. WHILE A FEW
SCATTERED -SHSNS WILL DOT THE AREA THROUGHOUT THE FORECAST...THESE
SHOULD NOT IMPACT THE TERMINALS IN ANY NOTABLE WAY. NORTHWEST FLOW
WILL VEER TO THE NORTH WITH THE PASSAGE OF A TROUGH LATE TONIGHT
INTO FRIDAY.

FOR DTW...CIGS WILL BE NEAR 5KFT MUCH OF THE FORECAST PERIOD WITH
JUST A FEW BREAKS POSSIBLE LATE TONIGHT/EARLY FRIDAY. TRUE CLEARING
WILL THEN OCCUR LATE IN THE FORECAST PERIOD...POST 00Z FRIDAY...AS
HIGH PRESSURE BEGINS TO NOSE INTO THE AREA. WNW WINDS WILL VEER TO
NORTH THEN NNE...AND REMAIN NEAR 10 KNOTS MUCH OF THE TIME.


//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS AOB 5000 FT THROUGH MUCH OF THE FCST PERIOD.

&&

.PREV DISCUSSION...ISSUED 356 PM EDT THU MAR 26 2015

SHORT TERM...THROUGH TONIGHT

LOW/MID LEVEL COLD ADVECTION CONTINUES TO SUPPORT AN EXTENSIVE
STRATOCU DECK ACROSS THE WESTERN GREAT LAKES. THIS BEGAN AS THE
STRONG UPPER JET AND ASSOCIATED LOW LEVEL BAROCLINIC ZONE SHIFTED
EASTWARD THIS MORNING. UPSTREAM CLOUD COVERAGE APPEARS SOLID ON
VISIBLE SATELLITE THIS AFTERNOON DESPITE SLIGHTLY MORE CELLULAR
APPEARANCE OVER FAR SRN MI LATELY. AS SUCH...EXPECT CLOUDY/MOSTLY
CLOUDY CONDITIONS TO PERSIST INTO THE EVENING WITH TEMPS HOLDING
STEADY OR FALLING.

SECONDARY COLD FRONT AT 19Z ALIGNED FROM GEORGIAN BAY THROUGH THE
FAR NORTHEASTERN U.P. AND INTO LAKE SUPERIOR. THIS FRONT WILL
PROGRESS THROUGH NORTHERN MICHIGAN AND LAKE HURON
OVERNIGHT...APPROACHING THE THUMB/SAGINAW VALLEY REGIONS BY AROUND
09Z. NAM FORECAST SOUNDINGS FOR BAX PAINT A FAVORABLE PICTURE FOR
LAKE EFFECT SNOW OVER THE THUMB AFTER 06Z. LOW-LEVEL WIND
TRAJECTORIES BECOME NORTH/NORTHEASTERLY WITH LAPSE RATES INCREASING
AND SUPERSATURATION WRT ICE UP TO ABOUT 750 HPA. 0-1 KM THETA-E
LAPSE RATES INCREASE TO 1-3 K/KM BY 12Z AS 925/850 MB TEMPS FALL TO
-9/-14C. CHARACTER OF THE LAKE EFFECT SNOW IS STILL SOMEWHAT
UNCERTAIN. SOME HI-RES GUIDANCE DEPICTS MORE DISORGANIZED LIGHT SNOW
PUSHING INTO THE THUMB INITIALLY AFTER 06-09Z AS LAPSE RATES AND
MOISTURE INCREASE...POSSIBLY EVOLVING INTO MORE OF A DOMINANT BAND
09-12Z AS LOW-LEVEL WINDS BECOME MORE UNIDIRECTIONAL OUT OF THE
NORTH-NORTHEAST...AT LEAST BEFORE DAYTIME HEATING COMMENCES. THIS
SCENARIO SEEMS PLAUSIBLE...ESPECIALLY IF LOW-LEVEL CONVERGENCE CAN
OCCUR. SNOW ACCUMS THROUGH 12Z GENERALLY 0.5-1 INCH FOR HURON COUNTY
WITH A HALF INCH OR LESS ELSEWHERE IN THE THUMB...BUT THIS WILL NEED
TO BE REFINED IF IT LOOKS LIKE A MORE DOMINANT LOCALIZED BAND WILL
SET UP.

ELSEWHERE...MOSTLY CLOUDY SKIES WITH CONTINUED COLD ADVECTION
ALLOWING LOWS TO DROP TO THE LOW/MID 20S. BEST CHANCE OF CLOUD DECK
SCATTERING OUT FOR A TIME WILL BE ACROSS THE SOUTH...BUT CONFIDENCE
IS NOT HIGH.

LONG TERM...

NORTHERN STREAM TROUGH OVER ONTARIO WILL ROTATE THROUGH THE CENTRAL
GREAT LAKES TOMORROW. 12Z SOUNDINGS OUT OF INTERNATIONAL FALLS AND
PICKLE LAKE ONTARIO REVEALED 850 MB TEMPS OF -14 C AND -20 C
RESPECTIVELY...WITH AN ALMOST TRUE NORTH WIND. THIS COLD
AIRMASS...ALBEIT MODIFIED SLIGHTLY...IS EXPECTED TO LEAD TO SOME
LAKE EFFECT SNOW SHOWERS TOMORROW WITH THE NORTHEAST TO NORTH FLOW
DEVELOPING...AS EVEN 925 MB TEMPS ARE EXPECTED TO FALL TO AROUND -13
C OVER LAKE HURON.

12Z NAM SHOWING GOOD 925 MB POSITIVE OMEGA SIGNAL PUSHING THROUGH
THE NORTHERN THUMB REGION AND EXTENDING SOUTHWEST THROUGH THE REST
OF SOUTHEAST MICHIGAN DURING THE DAY. WITH THE COMMENCEMENT OF
DAYTIME/SURFACE HEATING...PROBABLY GOING TO BECOME DISORGANIZED
ACTIVITY...WITH STEEP LOW LEVEL LAPSE RATES AND RATHER DEEP LAYER OF
SUPERSATURATION WITH RESPECT TO ICE TO SUPPORT SCATTERED SNOW
SHOWERS ACROSS MUCH OF THE AREA. WITH THE TRANSIENT AND DISORGANIZED
NATURE EXPECTED...WILL KEEP ACCUMULATIONS BELOW 1 INCH.

NORTH-NORTHEAST FLOW GRADUALLY WEAKENING FRIDAY NIGHT AS SURFACE
HIGH ATTEMPTS TO BUILD EASTWARD...BUT WITH THE HEART OF THE LOW
LEVEL COLD AIRMASS IN PLACE (850 MB TEMPS AS COLD AS -18
C)...ADDITIONAL LIGHT LAKE EFFECT SNOW SHOWERS ARE EXPECTED ACROSS
THE THUMB REGION. EXTEND OF CLOUD COVER BEYOND THE THUMB REGION
BECOMES CHALLENGING AS MUCH DRIER AIR AND ANTICYLONIC FLOW BEGINS TO
PUSH IN. REGARDLESS...EXPECTING MINS IN THE LOW TO MID TEENS.

CENTER OF HIGH BUILDING AND GENERAL SUBSIDENCE OVER LOWER MICHIGAN
ON SATURDAY SHOULD LEAD TO MOSTLY SUNNY SKIES...BUT COLD AIRMASS
(850 MB TEMPS IN THE NEGATIVE MID TEENS TO START THE DAY...RISING TO
-10 TO -11 C BY DAY`S END)...POINTS TO LOW TO MID 30S EVEN WITH FULL
SUNSHINE.

BRIEF RIDGING ON SUNDAY QUICKLY GIVES WAY TO ANOTHER TROUGH AS A LOW
PRESSURE SYSTEM SLIDES ACROSS THE HUDSON BAY AREA SUNDAY NIGHT INTO
MONDAY.  A COLD FRONT ASSOCIATED WITH THE LOW WILL TRANSVERSE ACROSS
THE GREAT LAKES REGION LATER ON SUNDAY.  EXACT TIMING OF THE FRONTAL
PASSAGE ACROSS THE CWA HAS YET TO BE PINNED DOWN DUE TO DIFFERENCES
CURRENTLY LAID OUT IN THE LATEST MODEL RUNS.  THIS PUTS IN TO
QUESTION PRECIPITATION TYPE THAT WILL ACCOMPANY THE FRONT DEPENDING
ON WHEN IT DOES PUSH THROUGH THE AREA.  NEXT WEEK LOOKS TO STAY
SOMEWHAT ACTIVE AS MORE SHORTWAVES MOVE ACROSS THE GREAT LAKES
REGION.  WARMER AIR DOES FINALLY START TO MAKE INROADS INTO THE AREA
NEXT WEEK...AS TEMPERATURES GET BACK TO NEAR NORMAL READINGS.

MARINE...

A VERY COLD AIRMASS WILL BE USHERED INTO THE CENTRAL GREAT LAKES
TONIGHT INTO TOMORROW...AS NORTHERLY WINDS GUST UP TO 30 KNOTS OVER
LAKE HURON. AIRMASS WILL EVEN BE COLD ENOUGH TO GENERATE SNOW
SHOWERS...BUT MOSTLY OVER SOUTHEAST MICHIGAN. WINDS WILL GRADUALLY
DIMINISH FRIDAY NIGHT...AS HIGH PRESSURE SETTLES OVER THE
REGION...LEADING TO LIGHT WINDS ON SATURDAY. SOUTHWEST WIND WILL
RAMP UP SATURDAY NIGHT INTO SUNDAY AS WE GET INTO RETURN FLOW AROUND
THE HIGH AND A COLD FRONT APPROACHES. EXPECTING WINDS OF AT LEAST 25
KNOTS OVER MUCH OF LAKE HURON.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT FRIDAY NIGHT FOR LHZ421-441-
     442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....DG
SHORT TERM...DT
LONG TERM....SF/SS
MARINE.......SF


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





000
FXUS63 KDTX 270359
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1159 PM EDT THU MAR 26 2015


.AVIATION...

MVFR TO LOWER VFR DECK IN THE 3-5KFT RANGE WILL BE PERSIST INTO
FRIDAY WITHIN COLD...CYCLONIC NORTHWEST FLOW. CIGS WILL TEND TO BE
LOWEST FROM KPTK NORTHWARD DURING THIS FORECAST PERIOD. WHILE A FEW
SCATTERED -SHSNS WILL DOT THE AREA THROUGHOUT THE FORECAST...THESE
SHOULD NOT IMPACT THE TERMINALS IN ANY NOTABLE WAY. NORTHWEST FLOW
WILL VEER TO THE NORTH WITH THE PASSAGE OF A TROUGH LATE TONIGHT
INTO FRIDAY.

FOR DTW...CIGS WILL BE NEAR 5KFT MUCH OF THE FORECAST PERIOD WITH
JUST A FEW BREAKS POSSIBLE LATE TONIGHT/EARLY FRIDAY. TRUE CLEARING
WILL THEN OCCUR LATE IN THE FORECAST PERIOD...POST 00Z FRIDAY...AS
HIGH PRESSURE BEGINS TO NOSE INTO THE AREA. WNW WINDS WILL VEER TO
NORTH THEN NNE...AND REMAIN NEAR 10 KNOTS MUCH OF THE TIME.


//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS AOB 5000 FT THROUGH MUCH OF THE FCST PERIOD.

&&

.PREV DISCUSSION...ISSUED 356 PM EDT THU MAR 26 2015

SHORT TERM...THROUGH TONIGHT

LOW/MID LEVEL COLD ADVECTION CONTINUES TO SUPPORT AN EXTENSIVE
STRATOCU DECK ACROSS THE WESTERN GREAT LAKES. THIS BEGAN AS THE
STRONG UPPER JET AND ASSOCIATED LOW LEVEL BAROCLINIC ZONE SHIFTED
EASTWARD THIS MORNING. UPSTREAM CLOUD COVERAGE APPEARS SOLID ON
VISIBLE SATELLITE THIS AFTERNOON DESPITE SLIGHTLY MORE CELLULAR
APPEARANCE OVER FAR SRN MI LATELY. AS SUCH...EXPECT CLOUDY/MOSTLY
CLOUDY CONDITIONS TO PERSIST INTO THE EVENING WITH TEMPS HOLDING
STEADY OR FALLING.

SECONDARY COLD FRONT AT 19Z ALIGNED FROM GEORGIAN BAY THROUGH THE
FAR NORTHEASTERN U.P. AND INTO LAKE SUPERIOR. THIS FRONT WILL
PROGRESS THROUGH NORTHERN MICHIGAN AND LAKE HURON
OVERNIGHT...APPROACHING THE THUMB/SAGINAW VALLEY REGIONS BY AROUND
09Z. NAM FORECAST SOUNDINGS FOR BAX PAINT A FAVORABLE PICTURE FOR
LAKE EFFECT SNOW OVER THE THUMB AFTER 06Z. LOW-LEVEL WIND
TRAJECTORIES BECOME NORTH/NORTHEASTERLY WITH LAPSE RATES INCREASING
AND SUPERSATURATION WRT ICE UP TO ABOUT 750 HPA. 0-1 KM THETA-E
LAPSE RATES INCREASE TO 1-3 K/KM BY 12Z AS 925/850 MB TEMPS FALL TO
-9/-14C. CHARACTER OF THE LAKE EFFECT SNOW IS STILL SOMEWHAT
UNCERTAIN. SOME HI-RES GUIDANCE DEPICTS MORE DISORGANIZED LIGHT SNOW
PUSHING INTO THE THUMB INITIALLY AFTER 06-09Z AS LAPSE RATES AND
MOISTURE INCREASE...POSSIBLY EVOLVING INTO MORE OF A DOMINANT BAND
09-12Z AS LOW-LEVEL WINDS BECOME MORE UNIDIRECTIONAL OUT OF THE
NORTH-NORTHEAST...AT LEAST BEFORE DAYTIME HEATING COMMENCES. THIS
SCENARIO SEEMS PLAUSIBLE...ESPECIALLY IF LOW-LEVEL CONVERGENCE CAN
OCCUR. SNOW ACCUMS THROUGH 12Z GENERALLY 0.5-1 INCH FOR HURON COUNTY
WITH A HALF INCH OR LESS ELSEWHERE IN THE THUMB...BUT THIS WILL NEED
TO BE REFINED IF IT LOOKS LIKE A MORE DOMINANT LOCALIZED BAND WILL
SET UP.

ELSEWHERE...MOSTLY CLOUDY SKIES WITH CONTINUED COLD ADVECTION
ALLOWING LOWS TO DROP TO THE LOW/MID 20S. BEST CHANCE OF CLOUD DECK
SCATTERING OUT FOR A TIME WILL BE ACROSS THE SOUTH...BUT CONFIDENCE
IS NOT HIGH.

LONG TERM...

NORTHERN STREAM TROUGH OVER ONTARIO WILL ROTATE THROUGH THE CENTRAL
GREAT LAKES TOMORROW. 12Z SOUNDINGS OUT OF INTERNATIONAL FALLS AND
PICKLE LAKE ONTARIO REVEALED 850 MB TEMPS OF -14 C AND -20 C
RESPECTIVELY...WITH AN ALMOST TRUE NORTH WIND. THIS COLD
AIRMASS...ALBEIT MODIFIED SLIGHTLY...IS EXPECTED TO LEAD TO SOME
LAKE EFFECT SNOW SHOWERS TOMORROW WITH THE NORTHEAST TO NORTH FLOW
DEVELOPING...AS EVEN 925 MB TEMPS ARE EXPECTED TO FALL TO AROUND -13
C OVER LAKE HURON.

12Z NAM SHOWING GOOD 925 MB POSITIVE OMEGA SIGNAL PUSHING THROUGH
THE NORTHERN THUMB REGION AND EXTENDING SOUTHWEST THROUGH THE REST
OF SOUTHEAST MICHIGAN DURING THE DAY. WITH THE COMMENCEMENT OF
DAYTIME/SURFACE HEATING...PROBABLY GOING TO BECOME DISORGANIZED
ACTIVITY...WITH STEEP LOW LEVEL LAPSE RATES AND RATHER DEEP LAYER OF
SUPERSATURATION WITH RESPECT TO ICE TO SUPPORT SCATTERED SNOW
SHOWERS ACROSS MUCH OF THE AREA. WITH THE TRANSIENT AND DISORGANIZED
NATURE EXPECTED...WILL KEEP ACCUMULATIONS BELOW 1 INCH.

NORTH-NORTHEAST FLOW GRADUALLY WEAKENING FRIDAY NIGHT AS SURFACE
HIGH ATTEMPTS TO BUILD EASTWARD...BUT WITH THE HEART OF THE LOW
LEVEL COLD AIRMASS IN PLACE (850 MB TEMPS AS COLD AS -18
C)...ADDITIONAL LIGHT LAKE EFFECT SNOW SHOWERS ARE EXPECTED ACROSS
THE THUMB REGION. EXTEND OF CLOUD COVER BEYOND THE THUMB REGION
BECOMES CHALLENGING AS MUCH DRIER AIR AND ANTICYLONIC FLOW BEGINS TO
PUSH IN. REGARDLESS...EXPECTING MINS IN THE LOW TO MID TEENS.

CENTER OF HIGH BUILDING AND GENERAL SUBSIDENCE OVER LOWER MICHIGAN
ON SATURDAY SHOULD LEAD TO MOSTLY SUNNY SKIES...BUT COLD AIRMASS
(850 MB TEMPS IN THE NEGATIVE MID TEENS TO START THE DAY...RISING TO
-10 TO -11 C BY DAY`S END)...POINTS TO LOW TO MID 30S EVEN WITH FULL
SUNSHINE.

BRIEF RIDGING ON SUNDAY QUICKLY GIVES WAY TO ANOTHER TROUGH AS A LOW
PRESSURE SYSTEM SLIDES ACROSS THE HUDSON BAY AREA SUNDAY NIGHT INTO
MONDAY.  A COLD FRONT ASSOCIATED WITH THE LOW WILL TRANSVERSE ACROSS
THE GREAT LAKES REGION LATER ON SUNDAY.  EXACT TIMING OF THE FRONTAL
PASSAGE ACROSS THE CWA HAS YET TO BE PINNED DOWN DUE TO DIFFERENCES
CURRENTLY LAID OUT IN THE LATEST MODEL RUNS.  THIS PUTS IN TO
QUESTION PRECIPITATION TYPE THAT WILL ACCOMPANY THE FRONT DEPENDING
ON WHEN IT DOES PUSH THROUGH THE AREA.  NEXT WEEK LOOKS TO STAY
SOMEWHAT ACTIVE AS MORE SHORTWAVES MOVE ACROSS THE GREAT LAKES
REGION.  WARMER AIR DOES FINALLY START TO MAKE INROADS INTO THE AREA
NEXT WEEK...AS TEMPERATURES GET BACK TO NEAR NORMAL READINGS.

MARINE...

A VERY COLD AIRMASS WILL BE USHERED INTO THE CENTRAL GREAT LAKES
TONIGHT INTO TOMORROW...AS NORTHERLY WINDS GUST UP TO 30 KNOTS OVER
LAKE HURON. AIRMASS WILL EVEN BE COLD ENOUGH TO GENERATE SNOW
SHOWERS...BUT MOSTLY OVER SOUTHEAST MICHIGAN. WINDS WILL GRADUALLY
DIMINISH FRIDAY NIGHT...AS HIGH PRESSURE SETTLES OVER THE
REGION...LEADING TO LIGHT WINDS ON SATURDAY. SOUTHWEST WIND WILL
RAMP UP SATURDAY NIGHT INTO SUNDAY AS WE GET INTO RETURN FLOW AROUND
THE HIGH AND A COLD FRONT APPROACHES. EXPECTING WINDS OF AT LEAST 25
KNOTS OVER MUCH OF LAKE HURON.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT FRIDAY NIGHT FOR LHZ421-441-
     442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....DG
SHORT TERM...DT
LONG TERM....SF/SS
MARINE.......SF


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




000
FXUS63 KDTX 262245
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
645 PM EDT THU MAR 26 2015


.AVIATION...

A GENERAL MVFR TO LOWER VFR DECK IN THE 3-5KFT RANGE WILL BE COMMON
THIS FORECAST WITHIN COLD...CYCLONIC NORTHWEST FLOW. CIGS WILL TEND
TO BE LOWEST FROM KPTK NORTHWARD DURING THIS FORECAST PERIOD. WHILE
A FEW SCATTERED -SHSN WILL BE POSSIBLE WITH A SURFACE TROUGH PASSAGE
ON FRIDAY...THESE SHOULD NOT IMPACT THE TERMINALS IN ANY NOTABLE
WAY. WEST TO NORTHWEST FLOW WILL VEER TO THE NORTH WITH THIS TROUGH
ON FRIDAY.

FOR DTW...CIGS WILL BE NEAR 5KFT MUCH OF THE FORECAST PERIOD WITH
JUST A FEW BREAKS POSSIBLE OVERNIGHT. TRUE CLEARING WILL OCCUR LATE
IN THE FORECAST PERIOD...POST 00Z FRIDAY...AS HIGH PRESSURE BEGINS
TO NOSE INTO THE AREA. WNW WINDS WILL VEER TO NORTH THEN NNE...AND
REMAIN NEAR 10 KNOTS MUCH OF THE TIME.


//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS AOB 5000 FT THROUGH MUCH OF THE FCST PERIOD.

&&

.PREV DISCUSSION...ISSUED 356 PM EDT THU MAR 26 2015

SHORT TERM...THROUGH TONIGHT

LOW/MID LEVEL COLD ADVECTION CONTINUES TO SUPPORT AN EXTENSIVE
STRATOCU DECK ACROSS THE WESTERN GREAT LAKES. THIS BEGAN AS THE
STRONG UPPER JET AND ASSOCIATED LOW LEVEL BAROCLINIC ZONE SHIFTED
EASTWARD THIS MORNING. UPSTREAM CLOUD COVERAGE APPEARS SOLID ON
VISIBLE SATELLITE THIS AFTERNOON DESPITE SLIGHTLY MORE CELLULAR
APPEARANCE OVER FAR SRN MI LATELY. AS SUCH...EXPECT CLOUDY/MOSTLY
CLOUDY CONDITIONS TO PERSIST INTO THE EVENING WITH TEMPS HOLDING
STEADY OR FALLING.

SECONDARY COLD FRONT AT 19Z ALIGNED FROM GEORGIAN BAY THROUGH THE
FAR NORTHEASTERN U.P. AND INTO LAKE SUPERIOR. THIS FRONT WILL
PROGRESS THROUGH NORTHERN MICHIGAN AND LAKE HURON
OVERNIGHT...APPROACHING THE THUMB/SAGINAW VALLEY REGIONS BY AROUND
09Z. NAM FORECAST SOUNDINGS FOR BAX PAINT A FAVORABLE PICTURE FOR
LAKE EFFECT SNOW OVER THE THUMB AFTER 06Z. LOW-LEVEL WIND
TRAJECTORIES BECOME NORTH/NORTHEASTERLY WITH LAPSE RATES INCREASING
AND SUPERSATURATION WRT ICE UP TO ABOUT 750 HPA. 0-1 KM THETA-E
LAPSE RATES INCREASE TO 1-3 K/KM BY 12Z AS 925/850 MB TEMPS FALL TO
-9/-14C. CHARACTER OF THE LAKE EFFECT SNOW IS STILL SOMEWHAT
UNCERTAIN. SOME HI-RES GUIDANCE DEPICTS MORE DISORGANIZED LIGHT SNOW
PUSHING INTO THE THUMB INITIALLY AFTER 06-09Z AS LAPSE RATES AND
MOISTURE INCREASE...POSSIBLY EVOLVING INTO MORE OF A DOMINANT BAND
09-12Z AS LOW-LEVEL WINDS BECOME MORE UNIDIRECTIONAL OUT OF THE
NORTH-NORTHEAST...AT LEAST BEFORE DAYTIME HEATING COMMENCES. THIS
SCENARIO SEEMS PLAUSIBLE...ESPECIALLY IF LOW-LEVEL CONVERGENCE CAN
OCCUR. SNOW ACCUMS THROUGH 12Z GENERALLY 0.5-1 INCH FOR HURON COUNTY
WITH A HALF INCH OR LESS ELSEWHERE IN THE THUMB...BUT THIS WILL NEED
TO BE REFINED IF IT LOOKS LIKE A MORE DOMINANT LOCALIZED BAND WILL
SET UP.

ELSEWHERE...MOSTLY CLOUDY SKIES WITH CONTINUED COLD ADVECTION
ALLOWING LOWS TO DROP TO THE LOW/MID 20S. BEST CHANCE OF CLOUD DECK
SCATTERING OUT FOR A TIME WILL BE ACROSS THE SOUTH...BUT CONFIDENCE
IS NOT HIGH.

LONG TERM...

NORTHERN STREAM TROUGH OVER ONTARIO WILL ROTATE THROUGH THE CENTRAL
GREAT LAKES TOMORROW. 12Z SOUNDINGS OUT OF INTERNATIONAL FALLS AND
PICKLE LAKE ONTARIO REVEALED 850 MB TEMPS OF -14 C AND -20 C
RESPECTIVELY...WITH AN ALMOST TRUE NORTH WIND. THIS COLD
AIRMASS...ALBEIT MODIFIED SLIGHTLY...IS EXPECTED TO LEAD TO SOME
LAKE EFFECT SNOW SHOWERS TOMORROW WITH THE NORTHEAST TO NORTH FLOW
DEVELOPING...AS EVEN 925 MB TEMPS ARE EXPECTED TO FALL TO AROUND -13
C OVER LAKE HURON.

12Z NAM SHOWING GOOD 925 MB POSITIVE OMEGA SIGNAL PUSHING THROUGH
THE NORTHERN THUMB REGION AND EXTENDING SOUTHWEST THROUGH THE REST
OF SOUTHEAST MICHIGAN DURING THE DAY. WITH THE COMMENCEMENT OF
DAYTIME/SURFACE HEATING...PROBABLY GOING TO BECOME DISORGANIZED
ACTIVITY...WITH STEEP LOW LEVEL LAPSE RATES AND RATHER DEEP LAYER OF
SUPERSATURATION WITH RESPECT TO ICE TO SUPPORT SCATTERED SNOW
SHOWERS ACROSS MUCH OF THE AREA. WITH THE TRANSIENT AND DISORGANIZED
NATURE EXPECTED...WILL KEEP ACCUMULATIONS BELOW 1 INCH.

NORTH-NORTHEAST FLOW GRADUALLY WEAKENING FRIDAY NIGHT AS SURFACE
HIGH ATTEMPTS TO BUILD EASTWARD...BUT WITH THE HEART OF THE LOW
LEVEL COLD AIRMASS IN PLACE (850 MB TEMPS AS COLD AS -18
C)...ADDITIONAL LIGHT LAKE EFFECT SNOW SHOWERS ARE EXPECTED ACROSS
THE THUMB REGION. EXTEND OF CLOUD COVER BEYOND THE THUMB REGION
BECOMES CHALLENGING AS MUCH DRIER AIR AND ANTICYLONIC FLOW BEGINS TO
PUSH IN. REGARDLESS...EXPECTING MINS IN THE LOW TO MID TEENS.

CENTER OF HIGH BUILDING AND GENERAL SUBSIDENCE OVER LOWER MICHIGAN
ON SATURDAY SHOULD LEAD TO MOSTLY SUNNY SKIES...BUT COLD AIRMASS
(850 MB TEMPS IN THE NEGATIVE MID TEENS TO START THE DAY...RISING TO
-10 TO -11 C BY DAY`S END)...POINTS TO LOW TO MID 30S EVEN WITH FULL
SUNSHINE.

BRIEF RIDGING ON SUNDAY QUICKLY GIVES WAY TO ANOTHER TROUGH AS A LOW
PRESSURE SYSTEM SLIDES ACROSS THE HUDSON BAY AREA SUNDAY NIGHT INTO
MONDAY.  A COLD FRONT ASSOCIATED WITH THE LOW WILL TRANSVERSE ACROSS
THE GREAT LAKES REGION LATER ON SUNDAY.  EXACT TIMING OF THE FRONTAL
PASSAGE ACROSS THE CWA HAS YET TO BE PINNED DOWN DUE TO DIFFERENCES
CURRENTLY LAID OUT IN THE LATEST MODEL RUNS.  THIS PUTS IN TO
QUESTION PRECIPITATION TYPE THAT WILL ACCOMPANY THE FRONT DEPENDING
ON WHEN IT DOES PUSH THROUGH THE AREA.  NEXT WEEK LOOKS TO STAY
SOMEWHAT ACTIVE AS MORE SHORTWAVES MOVE ACROSS THE GREAT LAKES
REGION.  WARMER AIR DOES FINALLY START TO MAKE INROADS INTO THE AREA
NEXT WEEK...AS TEMPERATURES GET BACK TO NEAR NORMAL READINGS.

MARINE...

A VERY COLD AIRMASS WILL BE USHERED INTO THE CENTRAL GREAT LAKES
TONIGHT INTO TOMORROW...AS NORTHERLY WINDS GUST UP TO 30 KNOTS OVER
LAKE HURON. AIRMASS WILL EVEN BE COLD ENOUGH TO GENERATE SNOW
SHOWERS...BUT MOSTLY OVER SOUTHEAST MICHIGAN. WINDS WILL GRADUALLY
DIMINISH FRIDAY NIGHT...AS HIGH PRESSURE SETTLES OVER THE
REGION...LEADING TO LIGHT WINDS ON SATURDAY. SOUTHWEST WIND WILL
RAMP UP SATURDAY NIGHT INTO SUNDAY AS WE GET INTO RETURN FLOW AROUND
THE HIGH AND A COLD FRONT APPROACHES. EXPECTING WINDS OF AT LEAST 25
KNOTS OVER MUCH OF LAKE HURON.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO MIDNIGHT EDT FRIDAY
     NIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....DG
SHORT TERM...DT
LONG TERM....SF/SS
MARINE.......SF


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




000
FXUS63 KDTX 262245
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
645 PM EDT THU MAR 26 2015


.AVIATION...

A GENERAL MVFR TO LOWER VFR DECK IN THE 3-5KFT RANGE WILL BE COMMON
THIS FORECAST WITHIN COLD...CYCLONIC NORTHWEST FLOW. CIGS WILL TEND
TO BE LOWEST FROM KPTK NORTHWARD DURING THIS FORECAST PERIOD. WHILE
A FEW SCATTERED -SHSN WILL BE POSSIBLE WITH A SURFACE TROUGH PASSAGE
ON FRIDAY...THESE SHOULD NOT IMPACT THE TERMINALS IN ANY NOTABLE
WAY. WEST TO NORTHWEST FLOW WILL VEER TO THE NORTH WITH THIS TROUGH
ON FRIDAY.

FOR DTW...CIGS WILL BE NEAR 5KFT MUCH OF THE FORECAST PERIOD WITH
JUST A FEW BREAKS POSSIBLE OVERNIGHT. TRUE CLEARING WILL OCCUR LATE
IN THE FORECAST PERIOD...POST 00Z FRIDAY...AS HIGH PRESSURE BEGINS
TO NOSE INTO THE AREA. WNW WINDS WILL VEER TO NORTH THEN NNE...AND
REMAIN NEAR 10 KNOTS MUCH OF THE TIME.


//DTW THRESHOLD PROBABILITIES...

* HIGH IN CEILINGS AOB 5000 FT THROUGH MUCH OF THE FCST PERIOD.

&&

.PREV DISCUSSION...ISSUED 356 PM EDT THU MAR 26 2015

SHORT TERM...THROUGH TONIGHT

LOW/MID LEVEL COLD ADVECTION CONTINUES TO SUPPORT AN EXTENSIVE
STRATOCU DECK ACROSS THE WESTERN GREAT LAKES. THIS BEGAN AS THE
STRONG UPPER JET AND ASSOCIATED LOW LEVEL BAROCLINIC ZONE SHIFTED
EASTWARD THIS MORNING. UPSTREAM CLOUD COVERAGE APPEARS SOLID ON
VISIBLE SATELLITE THIS AFTERNOON DESPITE SLIGHTLY MORE CELLULAR
APPEARANCE OVER FAR SRN MI LATELY. AS SUCH...EXPECT CLOUDY/MOSTLY
CLOUDY CONDITIONS TO PERSIST INTO THE EVENING WITH TEMPS HOLDING
STEADY OR FALLING.

SECONDARY COLD FRONT AT 19Z ALIGNED FROM GEORGIAN BAY THROUGH THE
FAR NORTHEASTERN U.P. AND INTO LAKE SUPERIOR. THIS FRONT WILL
PROGRESS THROUGH NORTHERN MICHIGAN AND LAKE HURON
OVERNIGHT...APPROACHING THE THUMB/SAGINAW VALLEY REGIONS BY AROUND
09Z. NAM FORECAST SOUNDINGS FOR BAX PAINT A FAVORABLE PICTURE FOR
LAKE EFFECT SNOW OVER THE THUMB AFTER 06Z. LOW-LEVEL WIND
TRAJECTORIES BECOME NORTH/NORTHEASTERLY WITH LAPSE RATES INCREASING
AND SUPERSATURATION WRT ICE UP TO ABOUT 750 HPA. 0-1 KM THETA-E
LAPSE RATES INCREASE TO 1-3 K/KM BY 12Z AS 925/850 MB TEMPS FALL TO
-9/-14C. CHARACTER OF THE LAKE EFFECT SNOW IS STILL SOMEWHAT
UNCERTAIN. SOME HI-RES GUIDANCE DEPICTS MORE DISORGANIZED LIGHT SNOW
PUSHING INTO THE THUMB INITIALLY AFTER 06-09Z AS LAPSE RATES AND
MOISTURE INCREASE...POSSIBLY EVOLVING INTO MORE OF A DOMINANT BAND
09-12Z AS LOW-LEVEL WINDS BECOME MORE UNIDIRECTIONAL OUT OF THE
NORTH-NORTHEAST...AT LEAST BEFORE DAYTIME HEATING COMMENCES. THIS
SCENARIO SEEMS PLAUSIBLE...ESPECIALLY IF LOW-LEVEL CONVERGENCE CAN
OCCUR. SNOW ACCUMS THROUGH 12Z GENERALLY 0.5-1 INCH FOR HURON COUNTY
WITH A HALF INCH OR LESS ELSEWHERE IN THE THUMB...BUT THIS WILL NEED
TO BE REFINED IF IT LOOKS LIKE A MORE DOMINANT LOCALIZED BAND WILL
SET UP.

ELSEWHERE...MOSTLY CLOUDY SKIES WITH CONTINUED COLD ADVECTION
ALLOWING LOWS TO DROP TO THE LOW/MID 20S. BEST CHANCE OF CLOUD DECK
SCATTERING OUT FOR A TIME WILL BE ACROSS THE SOUTH...BUT CONFIDENCE
IS NOT HIGH.

LONG TERM...

NORTHERN STREAM TROUGH OVER ONTARIO WILL ROTATE THROUGH THE CENTRAL
GREAT LAKES TOMORROW. 12Z SOUNDINGS OUT OF INTERNATIONAL FALLS AND
PICKLE LAKE ONTARIO REVEALED 850 MB TEMPS OF -14 C AND -20 C
RESPECTIVELY...WITH AN ALMOST TRUE NORTH WIND. THIS COLD
AIRMASS...ALBEIT MODIFIED SLIGHTLY...IS EXPECTED TO LEAD TO SOME
LAKE EFFECT SNOW SHOWERS TOMORROW WITH THE NORTHEAST TO NORTH FLOW
DEVELOPING...AS EVEN 925 MB TEMPS ARE EXPECTED TO FALL TO AROUND -13
C OVER LAKE HURON.

12Z NAM SHOWING GOOD 925 MB POSITIVE OMEGA SIGNAL PUSHING THROUGH
THE NORTHERN THUMB REGION AND EXTENDING SOUTHWEST THROUGH THE REST
OF SOUTHEAST MICHIGAN DURING THE DAY. WITH THE COMMENCEMENT OF
DAYTIME/SURFACE HEATING...PROBABLY GOING TO BECOME DISORGANIZED
ACTIVITY...WITH STEEP LOW LEVEL LAPSE RATES AND RATHER DEEP LAYER OF
SUPERSATURATION WITH RESPECT TO ICE TO SUPPORT SCATTERED SNOW
SHOWERS ACROSS MUCH OF THE AREA. WITH THE TRANSIENT AND DISORGANIZED
NATURE EXPECTED...WILL KEEP ACCUMULATIONS BELOW 1 INCH.

NORTH-NORTHEAST FLOW GRADUALLY WEAKENING FRIDAY NIGHT AS SURFACE
HIGH ATTEMPTS TO BUILD EASTWARD...BUT WITH THE HEART OF THE LOW
LEVEL COLD AIRMASS IN PLACE (850 MB TEMPS AS COLD AS -18
C)...ADDITIONAL LIGHT LAKE EFFECT SNOW SHOWERS ARE EXPECTED ACROSS
THE THUMB REGION. EXTEND OF CLOUD COVER BEYOND THE THUMB REGION
BECOMES CHALLENGING AS MUCH DRIER AIR AND ANTICYLONIC FLOW BEGINS TO
PUSH IN. REGARDLESS...EXPECTING MINS IN THE LOW TO MID TEENS.

CENTER OF HIGH BUILDING AND GENERAL SUBSIDENCE OVER LOWER MICHIGAN
ON SATURDAY SHOULD LEAD TO MOSTLY SUNNY SKIES...BUT COLD AIRMASS
(850 MB TEMPS IN THE NEGATIVE MID TEENS TO START THE DAY...RISING TO
-10 TO -11 C BY DAY`S END)...POINTS TO LOW TO MID 30S EVEN WITH FULL
SUNSHINE.

BRIEF RIDGING ON SUNDAY QUICKLY GIVES WAY TO ANOTHER TROUGH AS A LOW
PRESSURE SYSTEM SLIDES ACROSS THE HUDSON BAY AREA SUNDAY NIGHT INTO
MONDAY.  A COLD FRONT ASSOCIATED WITH THE LOW WILL TRANSVERSE ACROSS
THE GREAT LAKES REGION LATER ON SUNDAY.  EXACT TIMING OF THE FRONTAL
PASSAGE ACROSS THE CWA HAS YET TO BE PINNED DOWN DUE TO DIFFERENCES
CURRENTLY LAID OUT IN THE LATEST MODEL RUNS.  THIS PUTS IN TO
QUESTION PRECIPITATION TYPE THAT WILL ACCOMPANY THE FRONT DEPENDING
ON WHEN IT DOES PUSH THROUGH THE AREA.  NEXT WEEK LOOKS TO STAY
SOMEWHAT ACTIVE AS MORE SHORTWAVES MOVE ACROSS THE GREAT LAKES
REGION.  WARMER AIR DOES FINALLY START TO MAKE INROADS INTO THE AREA
NEXT WEEK...AS TEMPERATURES GET BACK TO NEAR NORMAL READINGS.

MARINE...

A VERY COLD AIRMASS WILL BE USHERED INTO THE CENTRAL GREAT LAKES
TONIGHT INTO TOMORROW...AS NORTHERLY WINDS GUST UP TO 30 KNOTS OVER
LAKE HURON. AIRMASS WILL EVEN BE COLD ENOUGH TO GENERATE SNOW
SHOWERS...BUT MOSTLY OVER SOUTHEAST MICHIGAN. WINDS WILL GRADUALLY
DIMINISH FRIDAY NIGHT...AS HIGH PRESSURE SETTLES OVER THE
REGION...LEADING TO LIGHT WINDS ON SATURDAY. SOUTHWEST WIND WILL
RAMP UP SATURDAY NIGHT INTO SUNDAY AS WE GET INTO RETURN FLOW AROUND
THE HIGH AND A COLD FRONT APPROACHES. EXPECTING WINDS OF AT LEAST 25
KNOTS OVER MUCH OF LAKE HURON.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO MIDNIGHT EDT FRIDAY
     NIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

AVIATION.....DG
SHORT TERM...DT
LONG TERM....SF/SS
MARINE.......SF


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





000
FXUS63 KDTX 261956
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
356 PM EDT THU MAR 26 2015

.SHORT TERM...THROUGH TONIGHT

LOW/MID LEVEL COLD ADVECTION CONTINUES TO SUPPORT AN EXTENSIVE
STRATOCU DECK ACROSS THE WESTERN GREAT LAKES. THIS BEGAN AS THE
STRONG UPPER JET AND ASSOCIATED LOW LEVEL BAROCLINIC ZONE SHIFTED
EASTWARD THIS MORNING. UPSTREAM CLOUD COVERAGE APPEARS SOLID ON
VISIBLE SATELLITE THIS AFTERNOON DESPITE SLIGHTLY MORE CELLULAR
APPEARANCE OVER FAR SRN MI LATELY. AS SUCH...EXPECT CLOUDY/MOSTLY
CLOUDY CONDITIONS TO PERSIST INTO THE EVENING WITH TEMPS HOLDING
STEADY OR FALLING.

SECONDARY COLD FRONT AT 19Z ALIGNED FROM GEORGIAN BAY THROUGH THE
FAR NORTHEASTERN U.P. AND INTO LAKE SUPERIOR. THIS FRONT WILL
PROGRESS THROUGH NORTHERN MICHIGAN AND LAKE HURON
OVERNIGHT...APPROACHING THE THUMB/SAGINAW VALLEY REGIONS BY AROUND
09Z. NAM FORECAST SOUNDINGS FOR BAX PAINT A FAVORABLE PICTURE FOR
LAKE EFFECT SNOW OVER THE THUMB AFTER 06Z. LOW-LEVEL WIND
TRAJECTORIES BECOME NORTH/NORTHEASTERLY WITH LAPSE RATES INCREASING
AND SUPERSATURATION WRT ICE UP TO ABOUT 750 HPA. 0-1 KM THETA-E
LAPSE RATES INCREASE TO 1-3 K/KM BY 12Z AS 925/850 MB TEMPS FALL TO
-9/-14C. CHARACTER OF THE LAKE EFFECT SNOW IS STILL SOMEWHAT
UNCERTAIN. SOME HI-RES GUIDANCE DEPICTS MORE DISORGANIZED LIGHT SNOW
PUSHING INTO THE THUMB INITIALLY AFTER 06-09Z AS LAPSE RATES AND
MOISTURE INCREASE...POSSIBLY EVOLVING INTO MORE OF A DOMINANT BAND
09-12Z AS LOW-LEVEL WINDS BECOME MORE UNIDIRECTIONAL OUT OF THE
NORTH-NORTHEAST...AT LEAST BEFORE DAYTIME HEATING COMMENCES. THIS
SCENARIO SEEMS PLAUSIBLE...ESPECIALLY IF LOW-LEVEL CONVERGENCE CAN
OCCUR. SNOW ACCUMS THROUGH 12Z GENERALLY 0.5-1 INCH FOR HURON COUNTY
WITH A HALF INCH OR LESS ELSEWHERE IN THE THUMB...BUT THIS WILL NEED
TO BE REFINED IF IT LOOKS LIKE A MORE DOMINANT LOCALIZED BAND WILL
SET UP.

ELSEWHERE...MOSTLY CLOUDY SKIES WITH CONTINUED COLD ADVECTION
ALLOWING LOWS TO DROP TO THE LOW/MID 20S. BEST CHANCE OF CLOUD DECK
SCATTERING OUT FOR A TIME WILL BE ACROSS THE SOUTH...BUT CONFIDENCE
IS NOT HIGH.

&&

.LONG TERM...

NORTHERN STREAM TROUGH OVER ONTARIO WILL ROTATE THROUGH THE CENTRAL
GREAT LAKES TOMORROW. 12Z SOUNDINGS OUT OF INTERNATIONAL FALLS AND
PICKLE LAKE ONTARIO REVEALED 850 MB TEMPS OF -14 C AND -20 C
RESPECTIVELY...WITH AN ALMOST TRUE NORTH WIND. THIS COLD
AIRMASS...ALBEIT MODIFIED SLIGHTLY...IS EXPECTED TO LEAD TO SOME
LAKE EFFECT SNOW SHOWERS TOMORROW WITH THE NORTHEAST TO NORTH FLOW
DEVELOPING...AS EVEN 925 MB TEMPS ARE EXPECTED TO FALL TO AROUND -13
C OVER LAKE HURON.

12Z NAM SHOWING GOOD 925 MB POSITIVE OMEGA SIGNAL PUSHING THROUGH
THE NORTHERN THUMB REGION AND EXTENDING SOUTHWEST THROUGH THE REST
OF SOUTHEAST MICHIGAN DURING THE DAY. WITH THE COMMENCEMENT OF
DAYTIME/SURFACE HEATING...PROBABLY GOING TO BECOME DISORGANIZED
ACTIVITY...WITH STEEP LOW LEVEL LAPSE RATES AND RATHER DEEP LAYER OF
SUPERSATURATION WITH RESPECT TO ICE TO SUPPORT SCATTERED SNOW
SHOWERS ACROSS MUCH OF THE AREA. WITH THE TRANSIENT AND DISORGANIZED
NATURE EXPECTED...WILL KEEP ACCUMULATIONS BELOW 1 INCH.

NORTH-NORTHEAST FLOW GRADUALLY WEAKENING FRIDAY NIGHT AS SURFACE
HIGH ATTEMPTS TO BUILD EASTWARD...BUT WITH THE HEART OF THE LOW
LEVEL COLD AIRMASS IN PLACE (850 MB TEMPS AS COLD AS -18
C)...ADDITIONAL LIGHT LAKE EFFECT SNOW SHOWERS ARE EXPECTED ACROSS
THE THUMB REGION. EXTEND OF CLOUD COVER BEYOND THE THUMB REGION
BECOMES CHALLENGING AS MUCH DRIER AIR AND ANTICYLONIC FLOW BEGINS TO
PUSH IN. REGARDLESS...EXPECTING MINS IN THE LOW TO MID TEENS.

CENTER OF HIGH BUILDING AND GENERAL SUBSIDENCE OVER LOWER MICHIGAN
ON SATURDAY SHOULD LEAD TO MOSTLY SUNNY SKIES...BUT COLD AIRMASS
(850 MB TEMPS IN THE NEGATIVE MID TEENS TO START THE DAY...RISING TO
-10 TO -11 C BY DAY`S END)...POINTS TO LOW TO MID 30S EVEN WITH FULL
SUNSHINE.

BRIEF RIDGING ON SUNDAY QUICKLY GIVES WAY TO ANOTHER TROUGH AS A LOW
PRESSURE SYSTEM SLIDES ACROSS THE HUDSON BAY AREA SUNDAY NIGHT INTO
MONDAY.  A COLD FRONT ASSOCIATED WITH THE LOW WILL TRANSVERSE ACROSS
THE GREAT LAKES REGION LATER ON SUNDAY.  EXACT TIMING OF THE FRONTAL
PASSAGE ACROSS THE CWA HAS YET TO BE PINNED DOWN DUE TO DIFFERENCES
CURRENTLY LAID OUT IN THE LATEST MODEL RUNS.  THIS PUTS IN TO
QUESTION PRECIPITATION TYPE THAT WILL ACCOMPANY THE FRONT DEPENDING
ON WHEN IT DOES PUSH THROUGH THE AREA.  NEXT WEEK LOOKS TO STAY
SOMEWHAT ACTIVE AS MORE SHORTWAVES MOVE ACROSS THE GREAT LAKES
REGION.  WARMER AIR DOES FINALLY START TO MAKE INROADS INTO THE AREA
NEXT WEEK...AS TEMPERATURES GET BACK TO NEAR NORMAL READINGS.

&&

.MARINE...

A VERY COLD AIRMASS WILL BE USHERED INTO THE CENTRAL GREAT LAKES
TONIGHT INTO TOMORROW...AS NORTHERLY WINDS GUST UP TO 30 KNOTS OVER
LAKE HURON. AIRMASS WILL EVEN BE COLD ENOUGH TO GENERATE SNOW
SHOWERS...BUT MOSTLY OVER SOUTHEAST MICHIGAN. WINDS WILL GRADUALLY
DIMINISH FRIDAY NIGHT...AS HIGH PRESSURE SETTLES OVER THE
REGION...LEADING TO LIGHT WINDS ON SATURDAY. SOUTHWEST WIND WILL
RAMP UP SATURDAY NIGHT INTO SUNDAY AS WE GET INTO RETURN FLOW AROUND
THE HIGH AND A COLD FRONT APPROACHES. EXPECTING WINDS OF AT LEAST 25
KNOTS OVER MUCH OF LAKE HURON.

&&

.AVIATION...ISSUED 114 PM EDT THU MAR 26 2015

SOLID VFR STRATOCU DECK OVERHEAD WILL PERSIST THROUGH THE AFTERNOON
AS COLD AIR POURS INTO THE REGION...POSSIBLY BREIFLY MVFR OVER
DETROIT METRO TERMINALS EARLY THIS AFTERNOON WHERE LOW LEVEL
MOISTURE HAS BEEN SLOWER TO EXIT. HIGHEST POTENTIAL FOR CIGS TO
LOWER INTO MVFR RANGE AFTER SUNSET FROM PTK NORTHWARD...LESS
CERTAINTY FOR THE METRO DETROIT TERMINALS. LIGHT SNOW SHOWERS ARE
POSSIBLE ALONG/BEHIND A FRONTAL BOUNDARY TOMORROW
MORNING/AFTERNOON...REFRAINED FROM INCLUSION IN THE TAFS FOR THIS
PERIOD UNTIL CONFIDENCE INCREASES.

FOR DTW...SOME OPPORTUNITY FOR CIGS AOB 5KFT TO SCATTER OUT LATER
THIS AFTERNOON INTO THE EARLY OVERNIGHT HOURS. SOME LIGHT SNOW
SHOWERS ARE POSSIBLE TOMORROW ALONG/BEHIND A COLD FRONT AFTER AROUND
15Z TOMORROW.


//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN CEILINGS BELOW 5000 FT THROUGH THE TAF PERIOD.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO MIDNIGHT EDT FRIDAY
     NIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

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


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





000
FXUS63 KDTX 261956
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
356 PM EDT THU MAR 26 2015

.SHORT TERM...THROUGH TONIGHT

LOW/MID LEVEL COLD ADVECTION CONTINUES TO SUPPORT AN EXTENSIVE
STRATOCU DECK ACROSS THE WESTERN GREAT LAKES. THIS BEGAN AS THE
STRONG UPPER JET AND ASSOCIATED LOW LEVEL BAROCLINIC ZONE SHIFTED
EASTWARD THIS MORNING. UPSTREAM CLOUD COVERAGE APPEARS SOLID ON
VISIBLE SATELLITE THIS AFTERNOON DESPITE SLIGHTLY MORE CELLULAR
APPEARANCE OVER FAR SRN MI LATELY. AS SUCH...EXPECT CLOUDY/MOSTLY
CLOUDY CONDITIONS TO PERSIST INTO THE EVENING WITH TEMPS HOLDING
STEADY OR FALLING.

SECONDARY COLD FRONT AT 19Z ALIGNED FROM GEORGIAN BAY THROUGH THE
FAR NORTHEASTERN U.P. AND INTO LAKE SUPERIOR. THIS FRONT WILL
PROGRESS THROUGH NORTHERN MICHIGAN AND LAKE HURON
OVERNIGHT...APPROACHING THE THUMB/SAGINAW VALLEY REGIONS BY AROUND
09Z. NAM FORECAST SOUNDINGS FOR BAX PAINT A FAVORABLE PICTURE FOR
LAKE EFFECT SNOW OVER THE THUMB AFTER 06Z. LOW-LEVEL WIND
TRAJECTORIES BECOME NORTH/NORTHEASTERLY WITH LAPSE RATES INCREASING
AND SUPERSATURATION WRT ICE UP TO ABOUT 750 HPA. 0-1 KM THETA-E
LAPSE RATES INCREASE TO 1-3 K/KM BY 12Z AS 925/850 MB TEMPS FALL TO
-9/-14C. CHARACTER OF THE LAKE EFFECT SNOW IS STILL SOMEWHAT
UNCERTAIN. SOME HI-RES GUIDANCE DEPICTS MORE DISORGANIZED LIGHT SNOW
PUSHING INTO THE THUMB INITIALLY AFTER 06-09Z AS LAPSE RATES AND
MOISTURE INCREASE...POSSIBLY EVOLVING INTO MORE OF A DOMINANT BAND
09-12Z AS LOW-LEVEL WINDS BECOME MORE UNIDIRECTIONAL OUT OF THE
NORTH-NORTHEAST...AT LEAST BEFORE DAYTIME HEATING COMMENCES. THIS
SCENARIO SEEMS PLAUSIBLE...ESPECIALLY IF LOW-LEVEL CONVERGENCE CAN
OCCUR. SNOW ACCUMS THROUGH 12Z GENERALLY 0.5-1 INCH FOR HURON COUNTY
WITH A HALF INCH OR LESS ELSEWHERE IN THE THUMB...BUT THIS WILL NEED
TO BE REFINED IF IT LOOKS LIKE A MORE DOMINANT LOCALIZED BAND WILL
SET UP.

ELSEWHERE...MOSTLY CLOUDY SKIES WITH CONTINUED COLD ADVECTION
ALLOWING LOWS TO DROP TO THE LOW/MID 20S. BEST CHANCE OF CLOUD DECK
SCATTERING OUT FOR A TIME WILL BE ACROSS THE SOUTH...BUT CONFIDENCE
IS NOT HIGH.

&&

.LONG TERM...

NORTHERN STREAM TROUGH OVER ONTARIO WILL ROTATE THROUGH THE CENTRAL
GREAT LAKES TOMORROW. 12Z SOUNDINGS OUT OF INTERNATIONAL FALLS AND
PICKLE LAKE ONTARIO REVEALED 850 MB TEMPS OF -14 C AND -20 C
RESPECTIVELY...WITH AN ALMOST TRUE NORTH WIND. THIS COLD
AIRMASS...ALBEIT MODIFIED SLIGHTLY...IS EXPECTED TO LEAD TO SOME
LAKE EFFECT SNOW SHOWERS TOMORROW WITH THE NORTHEAST TO NORTH FLOW
DEVELOPING...AS EVEN 925 MB TEMPS ARE EXPECTED TO FALL TO AROUND -13
C OVER LAKE HURON.

12Z NAM SHOWING GOOD 925 MB POSITIVE OMEGA SIGNAL PUSHING THROUGH
THE NORTHERN THUMB REGION AND EXTENDING SOUTHWEST THROUGH THE REST
OF SOUTHEAST MICHIGAN DURING THE DAY. WITH THE COMMENCEMENT OF
DAYTIME/SURFACE HEATING...PROBABLY GOING TO BECOME DISORGANIZED
ACTIVITY...WITH STEEP LOW LEVEL LAPSE RATES AND RATHER DEEP LAYER OF
SUPERSATURATION WITH RESPECT TO ICE TO SUPPORT SCATTERED SNOW
SHOWERS ACROSS MUCH OF THE AREA. WITH THE TRANSIENT AND DISORGANIZED
NATURE EXPECTED...WILL KEEP ACCUMULATIONS BELOW 1 INCH.

NORTH-NORTHEAST FLOW GRADUALLY WEAKENING FRIDAY NIGHT AS SURFACE
HIGH ATTEMPTS TO BUILD EASTWARD...BUT WITH THE HEART OF THE LOW
LEVEL COLD AIRMASS IN PLACE (850 MB TEMPS AS COLD AS -18
C)...ADDITIONAL LIGHT LAKE EFFECT SNOW SHOWERS ARE EXPECTED ACROSS
THE THUMB REGION. EXTEND OF CLOUD COVER BEYOND THE THUMB REGION
BECOMES CHALLENGING AS MUCH DRIER AIR AND ANTICYLONIC FLOW BEGINS TO
PUSH IN. REGARDLESS...EXPECTING MINS IN THE LOW TO MID TEENS.

CENTER OF HIGH BUILDING AND GENERAL SUBSIDENCE OVER LOWER MICHIGAN
ON SATURDAY SHOULD LEAD TO MOSTLY SUNNY SKIES...BUT COLD AIRMASS
(850 MB TEMPS IN THE NEGATIVE MID TEENS TO START THE DAY...RISING TO
-10 TO -11 C BY DAY`S END)...POINTS TO LOW TO MID 30S EVEN WITH FULL
SUNSHINE.

BRIEF RIDGING ON SUNDAY QUICKLY GIVES WAY TO ANOTHER TROUGH AS A LOW
PRESSURE SYSTEM SLIDES ACROSS THE HUDSON BAY AREA SUNDAY NIGHT INTO
MONDAY.  A COLD FRONT ASSOCIATED WITH THE LOW WILL TRANSVERSE ACROSS
THE GREAT LAKES REGION LATER ON SUNDAY.  EXACT TIMING OF THE FRONTAL
PASSAGE ACROSS THE CWA HAS YET TO BE PINNED DOWN DUE TO DIFFERENCES
CURRENTLY LAID OUT IN THE LATEST MODEL RUNS.  THIS PUTS IN TO
QUESTION PRECIPITATION TYPE THAT WILL ACCOMPANY THE FRONT DEPENDING
ON WHEN IT DOES PUSH THROUGH THE AREA.  NEXT WEEK LOOKS TO STAY
SOMEWHAT ACTIVE AS MORE SHORTWAVES MOVE ACROSS THE GREAT LAKES
REGION.  WARMER AIR DOES FINALLY START TO MAKE INROADS INTO THE AREA
NEXT WEEK...AS TEMPERATURES GET BACK TO NEAR NORMAL READINGS.

&&

.MARINE...

A VERY COLD AIRMASS WILL BE USHERED INTO THE CENTRAL GREAT LAKES
TONIGHT INTO TOMORROW...AS NORTHERLY WINDS GUST UP TO 30 KNOTS OVER
LAKE HURON. AIRMASS WILL EVEN BE COLD ENOUGH TO GENERATE SNOW
SHOWERS...BUT MOSTLY OVER SOUTHEAST MICHIGAN. WINDS WILL GRADUALLY
DIMINISH FRIDAY NIGHT...AS HIGH PRESSURE SETTLES OVER THE
REGION...LEADING TO LIGHT WINDS ON SATURDAY. SOUTHWEST WIND WILL
RAMP UP SATURDAY NIGHT INTO SUNDAY AS WE GET INTO RETURN FLOW AROUND
THE HIGH AND A COLD FRONT APPROACHES. EXPECTING WINDS OF AT LEAST 25
KNOTS OVER MUCH OF LAKE HURON.

&&

.AVIATION...ISSUED 114 PM EDT THU MAR 26 2015

SOLID VFR STRATOCU DECK OVERHEAD WILL PERSIST THROUGH THE AFTERNOON
AS COLD AIR POURS INTO THE REGION...POSSIBLY BREIFLY MVFR OVER
DETROIT METRO TERMINALS EARLY THIS AFTERNOON WHERE LOW LEVEL
MOISTURE HAS BEEN SLOWER TO EXIT. HIGHEST POTENTIAL FOR CIGS TO
LOWER INTO MVFR RANGE AFTER SUNSET FROM PTK NORTHWARD...LESS
CERTAINTY FOR THE METRO DETROIT TERMINALS. LIGHT SNOW SHOWERS ARE
POSSIBLE ALONG/BEHIND A FRONTAL BOUNDARY TOMORROW
MORNING/AFTERNOON...REFRAINED FROM INCLUSION IN THE TAFS FOR THIS
PERIOD UNTIL CONFIDENCE INCREASES.

FOR DTW...SOME OPPORTUNITY FOR CIGS AOB 5KFT TO SCATTER OUT LATER
THIS AFTERNOON INTO THE EARLY OVERNIGHT HOURS. SOME LIGHT SNOW
SHOWERS ARE POSSIBLE TOMORROW ALONG/BEHIND A COLD FRONT AFTER AROUND
15Z TOMORROW.


//DTW THRESHOLD PROBABILITIES...

* MEDIUM IN CEILINGS BELOW 5000 FT THROUGH THE TAF PERIOD.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO MIDNIGHT EDT FRIDAY
     NIGHT FOR LHZ421-441-442.

LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&

$$

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


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




    US Dept of Commerce
    National Oceanic and Atmospheric Administration
    National Weather Service
    1325 East West Highway
    Silver Spring, MD 20910
    Page Author: NWS Internet Services Team
Disclaimer
Information Quality
Credits
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities