Home > Products > Valid Products > AFD

000
FXUS63 KDTX 301116
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
616 AM EST FRI JAN 30 2015

.AVIATION...

DEEP COLUMN DRY AIR WILL FILTER INTO SOUTHEASTERN MICHIGAN TODAY.
THIS WILL BRING AN END TO THE SNOW SHOWER ACTIVITY AND LEAD TO
IMPROVING SKY CONDITIONS EARLY IN THE PERIOD. BREEZY WINDS WILL
PERSIST THIS MORNING AHEAD OF SURFACE HIGH PRESSURE. EXPECT
NORTHERLY WINDS OF 15 TO 25 KNOTS THROUGH MIDDAY...DIMINISHING
QUICKLY LATE THIS AFTERNOON. MOISTURE WILL WORK BACK INTO
SOUTHEASTERN MICHIGAN TONIGHT AS WIND DIRECTIONS BACK TO THE WEST.
MVFR CIGS WILL BE POSSIBLE LATE TONIGHT.

FOR DTW...CIGS AT OR BELOW 3500 FT AGL WILL SCATTER OUT VERY QUICKLY
IN THE PERIOD. SURFACE WINDS WILL REMAIN BREEZY OTHERWISE VFR
CONTIONS ARE ANITICPATED THROUGHOUT MUCH OF THE PERIOD.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT THIS MORNING...MEDIUM FOR LATE TONIGHT.

&&

.PREV DISCUSSION...ISSUED 400 AM EST FRI JAN 30 2015

SHORT TERM...LATE THIS AFTERNOON AND TONIGHT

A CONTRACTING MIDLEVEL TROUGH AXIS AND ATTENDENT SHORTWAVE IS
DIGGING THROUGH SOUTHEASTERN MICHIGAN AT 8Z. INCREASED MIXING DEPTHS
AND STRONG GRADIENT FLOW IN THE WAKE OF THE COLD FRONTAL PASSAGE HAS
LED TO BLUSTERLY CONDITIONS WITH WIDESPREAD NORTH TO NORTHEASTERLY
WINDS IN THE 25 TO 40 MPH RANGE.

STEEP LOW LEVEL LAPSE RATES IN ADDITION TO A REASONABLY DEEP
ISOTHERMAL LAYER HANGING AROUND -15C RESULTED IN A WIDESPREAD
COVERAGE OF LIGHT SNOW FOR THE EASTERN 1/2 TO 2/3RDS OF THE CWA.
GAUGING FROM SURFACE OBSERVATIONS AND REFLECTIVITY...SUSPECT THAT
ACCUMULATIONS HAVE BEEN VERY LIGHT AND LIKELY EVEN INDISCERNIBLE
GIVEN THE BLOWING COMPONENT. THE DEPENDENCE OF THE SETUP ON
THERMODYNAMICS AND MOISTURE SUGGESTS THIS SNOW WILL RAPIDLY WIND
DOWN THIS MORNING AS DRY AIR ADVECTING INTO THE AREA DRIES OUT THE
800-900MB LAYER. EXPECTATIONS ARE FOR THIS TO OCCUR BY 8AM. LAST FEW
REFLECTIVITY IMAGES...SHOW SOME BANDING OF THE SNOW. THIS APPEARS TO
BE A DOWNSTREAM RESPONSE TO MASS CONVERGENCE IN ADVANCE OF YET
ANOTHER THETA E DISCONTINUITY. OVERALL STRUCTURE AND APPEARANCE
SUGGESTS A SQUALL LIKE BEHAVIOR. THE PROBLEM IS...HAVE NOT SEEN ANY
SIGNIFICANT REDUCTION IN SFC OBSERVATIONS...AND IF THIS IS IN FACT
THE FORCING...LONGEVITY OF THE SETUP IS VERY SHORT TERM...OVER THE
NEXT COUPLE OF HOURS OR LESS. CURRENT THINKING IS THIS WILL END
BEFORE THE START OF THE MORNING COMMUTE. WILL MONITOR FOR NOW AND
ADDRESS WITH SPS IF NEED BE.

THE TROUGH AXIS WILL QUICKLY TURN TO A NEGATIVE TILT PUSHING WELL
EAST OF LOWER MICHIGAN TODAY ALLOWING SURFACE HIGH PRESSURE TO
AGGRESSIVELY BUILD EASTWARD. EXPECT BREEZY NORTHERLIES THROUGH THE
MORNING HOURS...THEN QUICKLY DIMINISHING LATE THIS AFTERNOON.
TEMPERATURES TODAY WILL BE COLD...RANGING BETWEEN 15 AND 20 DEGREES
FOR HIGHS.

A FLAT SHORTWAVE RIDGE IS FORECASTED TO ZIP ACROSS THE WESTERN GREAT
LAKES TONIGHT NUDGING THE THETA E GRADIENT UP AGAINST SOUTHEASTERN
MICHIGAN VERY LATE TONIGHT. WEAK SHORTWAVE ENERGY ON THE BACKSIDE OF
THE RIDGE WILL ARRIVE...BUT UNDER A HEAVY DOSE OF
SHEARING/CONFLUENCE ALOFT. QUALITATIVELY...THE AREA WILL BE IN THE
CORRECT SPOT FOR ASCENT DUE TO ISENTROPIC ASCENT ALOFT. FOR THIS
REASON WILL INCLUDE A LOW CHANCE POP TONIGHT...BUT MOISTURE BELOW 10
KFT AGL WILL BE LACKING. NO SNOW ACCUMULATIONS ARE EXPECTED.
MASSAGED TEMPERATURES DOWNWARD GIVEN THE PROJECTED
DEWPOINTS...CURRENT FORECAST WILL HAVE LOWS RANGING IN THE SINGLE
DIGITS ABOVE ZERO.

LONG TERM... SATURDAY THROUGH THURSDAY

PRIMARY FOCUS DURING THIS LONG TERM PERIOD CENTERS ON THE SUNDAY AND
SUNDAY NIGHT PERIODS...WITH A SIZABLE SHIFT IN EXPECTATIONS TOWARD A
GREATER POTENTIAL OF A LONG DURATION ACCUMULATING SNOWFALL IMPACTING
A PORTION OF SE MICHIGAN.

COMPLEX UPPER LEVEL PATTERN HEADING INTO THE WEEKEND...FEATURING A
CLOSED MID LEVEL CIRCULATION NOW CENTERED OVER BAJA TUCKED BENEATH
AN ENERGETIC WEST-NORTHWEST NORTHERN STREAM.  MODEST HEIGHT FALLS
ATTENDANT TO A LEAD CLIPPER SYSTEM PIVOTING ACROSS SOUTH-CENTRAL
CANADA WILL SHIFT AN ARCTIC FRONTAL BOUNDARY SOUTH AND ACROSS THE
REGION SATURDAY NIGHT.  MODEST THERMAL RESPONSE ON SATURDAY AS THE
THE PRE-FRONTAL SOUTHWEST GRADIENT TEMPORARILY TAKES HOLD.  THIS
WILL ALLOW TEMPERATURES TO RECOVER INTO THE 30 DEGREE RANGE.  A
BRIEF INCREASE IN MOISTURE QUALITY IMMEDIATELY ALONG THE FRONTAL
SLOPE MAY BE SUFFICIENT TO GENERATE SOME LIGHT SNOW SHOWERS LATE
SATURDAY/SATURDAY EVENING...LOW POTENTIAL FOR ACCUMULATION GIVEN THE
LIMITED DURATION AND INTENSITY.

A PIECE OF THE SOUTHWEST CLOSED LOW WILL SHEAR EAST-NORTHEAST
COINCIDENT WITH THE ARRIVAL OF A STRONGER WAVE EMANATING OUT OF THE
GULF OF ALASKA.  THE INTERACTION OF THIS ENERGY YIELDING
CONSIDERABLE VARIANCE WITHIN THE MODEL SUITE IN RECENT DAYS...BUT
HAVE LARGELY CONVERGED ON A SOLUTION SPACE WHICH NOW PROVIDES A
NOTEWORTHY NORTHWARD ADJUSTMENT IN THE POSITIONING OF THE GOVERNING
DYNAMICS AND A CORRESPONDING SHIFT TOWARD GREATER SNOWFALL
POTENTIAL.  THIS PROCESS WILL INITIATE AN AGGRESSIVE NORTHEASTWARD
ADVECTION OF THE SOUTHERN PACIFIC MOISTURE PLUME CURRENTLY TIED TO
THE SOUTHWEST CONUS LOW.   THIS MOISTURE WILL QUICKLY WORK ACROSS
THE ELEVATED PORTION OF THE EXITING ARCTIC FRONT...RESULTING IN AN
EXPANDING AREA OF SNOWFALL BY LATE SATURDAY NIGHT.  THIS SETUP
POINTS TOWARD A LONG DURATION OF LIGHT TO MODERATE SNOWFALL SUNDAY
INTO EARLY SUNDAY NIGHT...FORCED THROUGH A SUSTAINED PERIOD OF MID
LEVEL FRONTOGENESIS UNDER FAVORABLE ENTRANCE REGION UPPER JET
DYNAMICS AND INCREMENTAL SPIKES IN CVA.  A DRY NORTHEAST FLOW AND
DIMINISHING ASCENT WITH NORTHWARD EXTENT WILL MAINTAIN A FIRM
NORTHERN GRADIENT TO THIS SNOWFALL...PROVIDING A HIGHER DEGREE OF
UNCERTAINTY ON THE POTENTIAL ACROSS THE TRI-CITIES AND THUMB
CORRIDOR.

MODEL MOISTURE FIELDS ALLOW SPECIFIC HUMIDITY WITHIN THE 850-700 MB
LAYER TO REACH 3 G/KG DURING THE PEAK OF THE EVENT.  THE LONG
RESIDENCE TIME OF THIS ENVIRONMENT TRANSLATES INTO A SIGNIFICANT
UPTICK IN QPF WITHIN THE NAM/GFS/ECMWF.  AT THIS STAGE AND GIVEN THE
SIZABLE MODEL ADJUSTMENT...GOING FORECAST WILL LEAN IN THE DIRECTION
OF THE NAM...WITH A LEERY EYE ON THE HIGHER END AMOUNTS NOW SHOWN ON
THE ECMWF /.4" M-59 CORRIDOR TO .7" OHIO BORDER/.  THE ENSUING POST-
FRONTAL COLD AIR ADVECTION SATURDAY NIGHT WILL LEAVE A COLDER
THERMODYNAMIC PROFILE IN PLACE...SUGGESTING SNOW RATIOS WILL ARRIVE
ABOVE CLIMO /BALLPARK 16-17:1 AT THIS STAGE/.  A BROADER 3 TO 6 INCH
TYPE SWATH LOOKS ATTAINABLE...WITH A 6+ INCH BAND NOW WITHIN THE
ENVELOP OF POSSIBILITIES.

MARINE...

ONGOING NORTHWEST GALES ACROSS LAKE HURON THIS MORNING WILL EASE
THROUGH THE AFTERNOON PERIOD AS HIGH PRESSURE BUILDS INTO THE
REGION.  WINDS WILL SHIFT TO SOUTHWESTERLY ON SATURDAY IN THE WAKE
OF THIS HIGH.  ARCTIC FRONT SHIFT THROUGH SATURDAY NIGHT WILL THEN
BRING AN INCREASING NORTHEAST WIND INTO SUNDAY.  THIS WILL RESULT IN
SOME GUSTS TO 30 KNOTS.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST THIS EVENING FOR LHZ362-
     363-441-462>464.

     GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LHZ362-363-421-
     441>443-462>464.

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

$$

AVIATION.....CB
SHORT TERM...CB
LONG TERM....MR
MARINE.......MR

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




000
FXUS63 KDTX 301116
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
616 AM EST FRI JAN 30 2015

.AVIATION...

DEEP COLUMN DRY AIR WILL FILTER INTO SOUTHEASTERN MICHIGAN TODAY.
THIS WILL BRING AN END TO THE SNOW SHOWER ACTIVITY AND LEAD TO
IMPROVING SKY CONDITIONS EARLY IN THE PERIOD. BREEZY WINDS WILL
PERSIST THIS MORNING AHEAD OF SURFACE HIGH PRESSURE. EXPECT
NORTHERLY WINDS OF 15 TO 25 KNOTS THROUGH MIDDAY...DIMINISHING
QUICKLY LATE THIS AFTERNOON. MOISTURE WILL WORK BACK INTO
SOUTHEASTERN MICHIGAN TONIGHT AS WIND DIRECTIONS BACK TO THE WEST.
MVFR CIGS WILL BE POSSIBLE LATE TONIGHT.

FOR DTW...CIGS AT OR BELOW 3500 FT AGL WILL SCATTER OUT VERY QUICKLY
IN THE PERIOD. SURFACE WINDS WILL REMAIN BREEZY OTHERWISE VFR
CONTIONS ARE ANITICPATED THROUGHOUT MUCH OF THE PERIOD.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT THIS MORNING...MEDIUM FOR LATE TONIGHT.

&&

.PREV DISCUSSION...ISSUED 400 AM EST FRI JAN 30 2015

SHORT TERM...LATE THIS AFTERNOON AND TONIGHT

A CONTRACTING MIDLEVEL TROUGH AXIS AND ATTENDENT SHORTWAVE IS
DIGGING THROUGH SOUTHEASTERN MICHIGAN AT 8Z. INCREASED MIXING DEPTHS
AND STRONG GRADIENT FLOW IN THE WAKE OF THE COLD FRONTAL PASSAGE HAS
LED TO BLUSTERLY CONDITIONS WITH WIDESPREAD NORTH TO NORTHEASTERLY
WINDS IN THE 25 TO 40 MPH RANGE.

STEEP LOW LEVEL LAPSE RATES IN ADDITION TO A REASONABLY DEEP
ISOTHERMAL LAYER HANGING AROUND -15C RESULTED IN A WIDESPREAD
COVERAGE OF LIGHT SNOW FOR THE EASTERN 1/2 TO 2/3RDS OF THE CWA.
GAUGING FROM SURFACE OBSERVATIONS AND REFLECTIVITY...SUSPECT THAT
ACCUMULATIONS HAVE BEEN VERY LIGHT AND LIKELY EVEN INDISCERNIBLE
GIVEN THE BLOWING COMPONENT. THE DEPENDENCE OF THE SETUP ON
THERMODYNAMICS AND MOISTURE SUGGESTS THIS SNOW WILL RAPIDLY WIND
DOWN THIS MORNING AS DRY AIR ADVECTING INTO THE AREA DRIES OUT THE
800-900MB LAYER. EXPECTATIONS ARE FOR THIS TO OCCUR BY 8AM. LAST FEW
REFLECTIVITY IMAGES...SHOW SOME BANDING OF THE SNOW. THIS APPEARS TO
BE A DOWNSTREAM RESPONSE TO MASS CONVERGENCE IN ADVANCE OF YET
ANOTHER THETA E DISCONTINUITY. OVERALL STRUCTURE AND APPEARANCE
SUGGESTS A SQUALL LIKE BEHAVIOR. THE PROBLEM IS...HAVE NOT SEEN ANY
SIGNIFICANT REDUCTION IN SFC OBSERVATIONS...AND IF THIS IS IN FACT
THE FORCING...LONGEVITY OF THE SETUP IS VERY SHORT TERM...OVER THE
NEXT COUPLE OF HOURS OR LESS. CURRENT THINKING IS THIS WILL END
BEFORE THE START OF THE MORNING COMMUTE. WILL MONITOR FOR NOW AND
ADDRESS WITH SPS IF NEED BE.

THE TROUGH AXIS WILL QUICKLY TURN TO A NEGATIVE TILT PUSHING WELL
EAST OF LOWER MICHIGAN TODAY ALLOWING SURFACE HIGH PRESSURE TO
AGGRESSIVELY BUILD EASTWARD. EXPECT BREEZY NORTHERLIES THROUGH THE
MORNING HOURS...THEN QUICKLY DIMINISHING LATE THIS AFTERNOON.
TEMPERATURES TODAY WILL BE COLD...RANGING BETWEEN 15 AND 20 DEGREES
FOR HIGHS.

A FLAT SHORTWAVE RIDGE IS FORECASTED TO ZIP ACROSS THE WESTERN GREAT
LAKES TONIGHT NUDGING THE THETA E GRADIENT UP AGAINST SOUTHEASTERN
MICHIGAN VERY LATE TONIGHT. WEAK SHORTWAVE ENERGY ON THE BACKSIDE OF
THE RIDGE WILL ARRIVE...BUT UNDER A HEAVY DOSE OF
SHEARING/CONFLUENCE ALOFT. QUALITATIVELY...THE AREA WILL BE IN THE
CORRECT SPOT FOR ASCENT DUE TO ISENTROPIC ASCENT ALOFT. FOR THIS
REASON WILL INCLUDE A LOW CHANCE POP TONIGHT...BUT MOISTURE BELOW 10
KFT AGL WILL BE LACKING. NO SNOW ACCUMULATIONS ARE EXPECTED.
MASSAGED TEMPERATURES DOWNWARD GIVEN THE PROJECTED
DEWPOINTS...CURRENT FORECAST WILL HAVE LOWS RANGING IN THE SINGLE
DIGITS ABOVE ZERO.

LONG TERM... SATURDAY THROUGH THURSDAY

PRIMARY FOCUS DURING THIS LONG TERM PERIOD CENTERS ON THE SUNDAY AND
SUNDAY NIGHT PERIODS...WITH A SIZABLE SHIFT IN EXPECTATIONS TOWARD A
GREATER POTENTIAL OF A LONG DURATION ACCUMULATING SNOWFALL IMPACTING
A PORTION OF SE MICHIGAN.

COMPLEX UPPER LEVEL PATTERN HEADING INTO THE WEEKEND...FEATURING A
CLOSED MID LEVEL CIRCULATION NOW CENTERED OVER BAJA TUCKED BENEATH
AN ENERGETIC WEST-NORTHWEST NORTHERN STREAM.  MODEST HEIGHT FALLS
ATTENDANT TO A LEAD CLIPPER SYSTEM PIVOTING ACROSS SOUTH-CENTRAL
CANADA WILL SHIFT AN ARCTIC FRONTAL BOUNDARY SOUTH AND ACROSS THE
REGION SATURDAY NIGHT.  MODEST THERMAL RESPONSE ON SATURDAY AS THE
THE PRE-FRONTAL SOUTHWEST GRADIENT TEMPORARILY TAKES HOLD.  THIS
WILL ALLOW TEMPERATURES TO RECOVER INTO THE 30 DEGREE RANGE.  A
BRIEF INCREASE IN MOISTURE QUALITY IMMEDIATELY ALONG THE FRONTAL
SLOPE MAY BE SUFFICIENT TO GENERATE SOME LIGHT SNOW SHOWERS LATE
SATURDAY/SATURDAY EVENING...LOW POTENTIAL FOR ACCUMULATION GIVEN THE
LIMITED DURATION AND INTENSITY.

A PIECE OF THE SOUTHWEST CLOSED LOW WILL SHEAR EAST-NORTHEAST
COINCIDENT WITH THE ARRIVAL OF A STRONGER WAVE EMANATING OUT OF THE
GULF OF ALASKA.  THE INTERACTION OF THIS ENERGY YIELDING
CONSIDERABLE VARIANCE WITHIN THE MODEL SUITE IN RECENT DAYS...BUT
HAVE LARGELY CONVERGED ON A SOLUTION SPACE WHICH NOW PROVIDES A
NOTEWORTHY NORTHWARD ADJUSTMENT IN THE POSITIONING OF THE GOVERNING
DYNAMICS AND A CORRESPONDING SHIFT TOWARD GREATER SNOWFALL
POTENTIAL.  THIS PROCESS WILL INITIATE AN AGGRESSIVE NORTHEASTWARD
ADVECTION OF THE SOUTHERN PACIFIC MOISTURE PLUME CURRENTLY TIED TO
THE SOUTHWEST CONUS LOW.   THIS MOISTURE WILL QUICKLY WORK ACROSS
THE ELEVATED PORTION OF THE EXITING ARCTIC FRONT...RESULTING IN AN
EXPANDING AREA OF SNOWFALL BY LATE SATURDAY NIGHT.  THIS SETUP
POINTS TOWARD A LONG DURATION OF LIGHT TO MODERATE SNOWFALL SUNDAY
INTO EARLY SUNDAY NIGHT...FORCED THROUGH A SUSTAINED PERIOD OF MID
LEVEL FRONTOGENESIS UNDER FAVORABLE ENTRANCE REGION UPPER JET
DYNAMICS AND INCREMENTAL SPIKES IN CVA.  A DRY NORTHEAST FLOW AND
DIMINISHING ASCENT WITH NORTHWARD EXTENT WILL MAINTAIN A FIRM
NORTHERN GRADIENT TO THIS SNOWFALL...PROVIDING A HIGHER DEGREE OF
UNCERTAINTY ON THE POTENTIAL ACROSS THE TRI-CITIES AND THUMB
CORRIDOR.

MODEL MOISTURE FIELDS ALLOW SPECIFIC HUMIDITY WITHIN THE 850-700 MB
LAYER TO REACH 3 G/KG DURING THE PEAK OF THE EVENT.  THE LONG
RESIDENCE TIME OF THIS ENVIRONMENT TRANSLATES INTO A SIGNIFICANT
UPTICK IN QPF WITHIN THE NAM/GFS/ECMWF.  AT THIS STAGE AND GIVEN THE
SIZABLE MODEL ADJUSTMENT...GOING FORECAST WILL LEAN IN THE DIRECTION
OF THE NAM...WITH A LEERY EYE ON THE HIGHER END AMOUNTS NOW SHOWN ON
THE ECMWF /.4" M-59 CORRIDOR TO .7" OHIO BORDER/.  THE ENSUING POST-
FRONTAL COLD AIR ADVECTION SATURDAY NIGHT WILL LEAVE A COLDER
THERMODYNAMIC PROFILE IN PLACE...SUGGESTING SNOW RATIOS WILL ARRIVE
ABOVE CLIMO /BALLPARK 16-17:1 AT THIS STAGE/.  A BROADER 3 TO 6 INCH
TYPE SWATH LOOKS ATTAINABLE...WITH A 6+ INCH BAND NOW WITHIN THE
ENVELOP OF POSSIBILITIES.

MARINE...

ONGOING NORTHWEST GALES ACROSS LAKE HURON THIS MORNING WILL EASE
THROUGH THE AFTERNOON PERIOD AS HIGH PRESSURE BUILDS INTO THE
REGION.  WINDS WILL SHIFT TO SOUTHWESTERLY ON SATURDAY IN THE WAKE
OF THIS HIGH.  ARCTIC FRONT SHIFT THROUGH SATURDAY NIGHT WILL THEN
BRING AN INCREASING NORTHEAST WIND INTO SUNDAY.  THIS WILL RESULT IN
SOME GUSTS TO 30 KNOTS.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST THIS EVENING FOR LHZ362-
     363-441-462>464.

     GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LHZ362-363-421-
     441>443-462>464.

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

$$

AVIATION.....CB
SHORT TERM...CB
LONG TERM....MR
MARINE.......MR

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





000
FXUS63 KDTX 300900
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
400 AM EST FRI JAN 30 2015

.SHORT TERM...LATE THIS AFTERNOON AND TONIGHT

A CONTRACTING MIDLEVEL TROUGH AXIS AND ATTENDENT SHORTWAVE IS
DIGGING THROUGH SOUTHEASTERN MICHIGAN AT 8Z. INCREASED MIXING DEPTHS
AND STRONG GRADIENT FLOW IN THE WAKE OF THE COLD FRONTAL PASSAGE HAS
LED TO BLUSTERLY CONDITIONS WITH WIDESPREAD NORTH TO NORTHEASTERLY
WINDS IN THE 25 TO 40 MPH RANGE.

STEEP LOW LEVEL LAPSE RATES IN ADDITION TO A REASONABLY DEEP
ISOTHERMAL LAYER HANGING AROUND -15C RESULTED IN A WIDESPREAD
COVERAGE OF LIGHT SNOW FOR THE EASTERN 1/2 TO 2/3RDS OF THE CWA.
GAUGING FROM SURFACE OBSERVATIONS AND REFLECTIVITY...SUSPECT THAT
ACCUMULATIONS HAVE BEEN VERY LIGHT AND LIKELY EVEN INDISCERNIBLE
GIVEN THE BLOWING COMPONENT. THE DEPENDENCE OF THE SETUP ON
THERMODYNAMICS AND MOISTURE SUGGESTS THIS SNOW WILL RAPIDLY WIND
DOWN THIS MORNING AS DRY AIR ADVECTING INTO THE AREA DRIES OUT THE
800-900MB LAYER. EXPECTATIONS ARE FOR THIS TO OCCUR BY 8AM. LAST FEW
REFLECTIVITY IMAGES...SHOW SOME BANDING OF THE SNOW. THIS APPEARS TO
BE A DOWNSTREAM RESPONSE TO MASS CONVERGENCE IN ADVANCE OF YET
ANOTHER THETA E DISCONTINUITY. OVERALL STRUCTURE AND APPEARANCE
SUGGESTS A SQUALL LIKE BEHAVIOR. THE PROBLEM IS...HAVE NOT SEEN ANY
SIGNIFICANT REDUCTION IN SFC OBSERVATIONS...AND IF THIS IS IN FACT
THE FORCING...LONGEVITY OF THE SETUP IS VERY SHORT TERM...OVER THE
NEXT COUPLE OF HOURS OR LESS. CURRENT THINKING IS THIS WILL END
BEFORE THE START OF THE MORNING COMMUTE. WILL MONITOR FOR NOW AND
ADDRESS WITH SPS IF NEED BE.

THE TROUGH AXIS WILL QUICKLY TURN TO A NEGATIVE TILT PUSHING WELL
EAST OF LOWER MICHIGAN TODAY ALLOWING SURFACE HIGH PRESSURE TO
AGGRESSIVELY BUILD EASTWARD. EXPECT BREEZY NORTHERLIES THROUGH THE
MORNING HOURS...THEN QUICKLY DIMINISHING LATE THIS AFTERNOON.
TEMPERATURES TODAY WILL BE COLD...RANGING BETWEEN 15 AND 20 DEGREES
FOR HIGHS.

A FLAT SHORTWAVE RIDGE IS FORECASTED TO ZIP ACROSS THE WESTERN GREAT
LAKES TONIGHT NUDGING THE THETA E GRADIENT UP AGAINST SOUTHEASTERN
MICHIGAN VERY LATE TONIGHT. WEAK SHORTWAVE ENERGY ON THE BACKSIDE OF
THE RIDGE WILL ARRIVE...BUT UNDER A HEAVY DOSE OF
SHEARING/CONFLUENCE ALOFT. QUALITATIVELY...THE AREA WILL BE IN THE
CORRECT SPOT FOR ASCENT DUE TO ISENTROPIC ASCENT ALOFT. FOR THIS
REASON WILL INCLUDE A LOW CHANCE POP TONIGHT...BUT MOISTURE BELOW 10
KFT AGL WILL BE LACKING. NO SNOW ACCUMULATIONS ARE EXPECTED.
MASSAGED TEMPERATURES DOWNWARD GIVEN THE PROJECTED
DEWPOINTS...CURRENT FORECAST WILL HAVE LOWS RANGING IN THE SINGLE
DIGITS ABOVE ZERO.

&&

.LONG TERM... SATURDAY THROUGH THURSDAY

PRIMARY FOCUS DURING THIS LONG TERM PERIOD CENTERS ON THE SUNDAY AND
SUNDAY NIGHT PERIODS...WITH A SIZABLE SHIFT IN EXPECTATIONS TOWARD A
GREATER POTENTIAL OF A LONG DURATION ACCUMULATING SNOWFALL IMPACTING
A PORTION OF SE MICHIGAN.

COMPLEX UPPER LEVEL PATTERN HEADING INTO THE WEEKEND...FEATURING A
CLOSED MID LEVEL CIRCULATION NOW CENTERED OVER BAJA TUCKED BENEATH
AN ENERGETIC WEST-NORTHWEST NORTHERN STREAM.  MODEST HEIGHT FALLS
ATTENDANT TO A LEAD CLIPPER SYSTEM PIVOTING ACROSS SOUTH-CENTRAL
CANADA WILL SHIFT AN ARCTIC FRONTAL BOUNDARY SOUTH AND ACROSS THE
REGION SATURDAY NIGHT.  MODEST THERMAL RESPONSE ON SATURDAY AS THE
THE PRE-FRONTAL SOUTHWEST GRADIENT TEMPORARILY TAKES HOLD.  THIS
WILL ALLOW TEMPERATURES TO RECOVER INTO THE 30 DEGREE RANGE.  A
BRIEF INCREASE IN MOISTURE QUALITY IMMEDIATELY ALONG THE FRONTAL
SLOPE MAY BE SUFFICIENT TO GENERATE SOME LIGHT SNOW SHOWERS LATE
SATURDAY/SATURDAY EVENING...LOW POTENTIAL FOR ACCUMULATION GIVEN THE
LIMITED DURATION AND INTENSITY.

A PIECE OF THE SOUTHWEST CLOSED LOW WILL SHEAR EAST-NORTHEAST
COINCIDENT WITH THE ARRIVAL OF A STRONGER WAVE EMANATING OUT OF THE
GULF OF ALASKA.  THE INTERACTION OF THIS ENERGY YIELDING
CONSIDERABLE VARIANCE WITHIN THE MODEL SUITE IN RECENT DAYS...BUT
HAVE LARGELY CONVERGED ON A SOLUTION SPACE WHICH NOW PROVIDES A
NOTEWORTHY NORTHWARD ADJUSTMENT IN THE POSITIONING OF THE GOVERNING
DYNAMICS AND A CORRESPONDING SHIFT TOWARD GREATER SNOWFALL
POTENTIAL.  THIS PROCESS WILL INITIATE AN AGGRESSIVE NORTHEASTWARD
ADVECTION OF THE SOUTHERN PACIFIC MOISTURE PLUME CURRENTLY TIED TO
THE SOUTHWEST CONUS LOW.   THIS MOISTURE WILL QUICKLY WORK ACROSS
THE ELEVATED PORTION OF THE EXITING ARCTIC FRONT...RESULTING IN AN
EXPANDING AREA OF SNOWFALL BY LATE SATURDAY NIGHT.  THIS SETUP
POINTS TOWARD A LONG DURATION OF LIGHT TO MODERATE SNOWFALL SUNDAY
INTO EARLY SUNDAY NIGHT...FORCED THROUGH A SUSTAINED PERIOD OF MID
LEVEL FRONTOGENESIS UNDER FAVORABLE ENTRANCE REGION UPPER JET
DYNAMICS AND INCREMENTAL SPIKES IN CVA.  A DRY NORTHEAST FLOW AND
DIMINISHING ASCENT WITH NORTHWARD EXTENT WILL MAINTAIN A FIRM
NORTHERN GRADIENT TO THIS SNOWFALL...PROVIDING A HIGHER DEGREE OF
UNCERTAINTY ON THE POTENTIAL ACROSS THE TRI-CITIES AND THUMB
CORRIDOR.

MODEL MOISTURE FIELDS ALLOW SPECIFIC HUMIDITY WITHIN THE 850-700 MB
LAYER TO REACH 3 G/KG DURING THE PEAK OF THE EVENT.  THE LONG
RESIDENCE TIME OF THIS ENVIRONMENT TRANSLATES INTO A SIGNIFICANT
UPTICK IN QPF WITHIN THE NAM/GFS/ECMWF.  AT THIS STAGE AND GIVEN THE
SIZABLE MODEL ADJUSTMENT...GOING FORECAST WILL LEAN IN THE DIRECTION
OF THE NAM...WITH A LEERY EYE ON THE HIGHER END AMOUNTS NOW SHOWN ON
THE ECMWF /.4" M-59 CORRIDOR TO .7" OHIO BORDER/.  THE ENSUING POST-
FRONTAL COLD AIR ADVECTION SATURDAY NIGHT WILL LEAVE A COLDER
THERMODYNAMIC PROFILE IN PLACE...SUGGESTING SNOW RATIOS WILL ARRIVE
ABOVE CLIMO /BALLPARK 16-17:1 AT THIS STAGE/.  A BROADER 3 TO 6 INCH
TYPE SWATH LOOKS ATTAINABLE...WITH A 6+ INCH BAND NOW WITHIN THE
ENVELOP OF POSSIBILITIES.

&&

.MARINE...

ONGOING NORTHWEST GALES ACROSS LAKE HURON THIS MORNING WILL EASE
THROUGH THE AFTERNOON PERIOD AS HIGH PRESSURE BUILDS INTO THE
REGION.  WINDS WILL SHIFT TO SOUTHWESTERLY ON SATURDAY IN THE WAKE
OF THIS HIGH.  ARCTIC FRONT SHIFT THROUGH SATURDAY NIGHT WILL THEN
BRING AN INCREASING NORTHEAST WIND INTO SUNDAY.  THIS WILL RESULT IN
SOME GUSTS TO 30 KNOTS.

&&

.AVIATION...ISSUED 1153 PM EST THU JAN 29 2015

SHALLOW COLD AIR ADVECTION UNDER A DEEP LOW LEVEL INVERSION WILL
SUSTAIN MVFR CIGS AND GUSTY WINDS...POSSIBLY GUSTING TO 30 KNOTS AT
TIMES...OVERNIGHT. HIGH PRESSURE BUILDING IN ACROSS TEH WESTERN
GREAT LAKES ON FRIDAY WILL CLEAR OUT THE CEILINGS FRIDAY
MORNING...WITH LIGHTER WINDS EXPECTED BY THE AFTERNOON AS THE
PRESSURE GRADIENT LOOSENS.

FOR DTW...CIGS AROUND 3000 FT ARE EXPECTED THROUGH FRIDAY MORNING
WHEN HIGH PRESSURE BRINGS DRIER AIR IN OVER THE CENTRAL GREAT LAKES.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT OVERNIGHT.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS OVERNIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST THIS EVENING FOR LHZ362-
     363-441-462>464.

     GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LHZ362-363-421-
     441>443-462>464.

     HEAVY FREEZING SPRAY WARNING UNTIL 4 AM EST EARLY THIS MORNING FOR
     LHZ361.

     GALE WARNING UNTIL 4 AM EST EARLY THIS MORNING FOR LHZ361.

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

$$

SHORT TERM...CB
LONG TERM....MR
MARINE.......MR
AVIATION.....KURIMSKI


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




000
FXUS63 KDTX 300453
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1153 PM EST THU JAN 29 2015


.AVIATION...

SHALLOW COLD AIR ADVECTION UNDER A DEEP LOW LEVEL INVERSION WILL
SUSTAIN MVFR CIGS AND GUSTY WINDS...POSSIBLY GUSTING TO 30 KNOTS AT
TIMES...OVERNIGHT. HIGH PRESSURE BUILDING IN ACROSS TEH WESTERN
GREAT LAKES ON FRIDAY WILL CLEAR OUT THE CEILINGS FRIDAY
MORNING...WITH LIGHTER WINDS EXPECTED BY THE AFTERNOON AS THE
PRESSURE GRADIENT LOOSENS.

FOR DTW...CIGS AROUND 3000 FT ARE EXPECTED THROUGH FRIDAY MORNING
WHEN HIGH PRESSURE BRINGS DRIER AIR IN OVER THE CENTRAL GREAT LAKES.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT OVERNIGHT.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS OVERNIGHT.

&&

.PREV DISCUSSION...ISSUED 806 PM EST THU JAN 29 2015

UPDATE...

LARGE SCALE SUBSIDENCE BEHIND A DEPARTING COLD FRONT HAS BROUGHT
AN END TO THE SNOW SHOWERS ACROSS SOUTHEAST MICHIGAN EARLY THIS
EVENING...WITH ONLY SOME LIGHT SNOW SHOWERS OR FLURRIES EXPECTED
THE REST OF THE NIGHT WITH NO ADDITIONAL ACCUMULATIONS. SNOWFALL
ACCUMULATIONS THIS AFTERNOON AND EARLY THIS EVENING CAME IN AT
ABOUT 1 TO 1.5 INCHES FROM DETROIT NORTHWARD. WHILE THE FRONT HAS
BROUGHT AN END TO THE SNOW...IT HAS BROUGHT A MARKED INCREASE IN
WIND SPEEDS WITH NORTHWESTERLY WINDS GUSTING TO 20 TO 30 MPH. A
SECONDARY COLD FRONT WILL SEND TEMPERATURES PLUMMETING LATER
TONIGHT AS WIND SPEEDS INCREASE FURTHER TO AROUND 30 MPH. THE
COMBINATION OF COLD AND WIND WILL SEND WIND CHILLS DOWN BELOW ZERO
LATE TONIGHT.

PREV DISCUSSION...ISSUED 254 PM EST THU JAN 29 2015

SHORT TERM...LATE THIS AFTERNOON AND TONIGHT

THE BACK EDGE OF THE PRECIPITATION SHIELD WILL CONTINUE ON AN
EASTWARD TRACK LATE THIS AFTERNOON...ADVANCING ACROSS SE MI OVER THE
NEXT TWO TO THREE HOURS. SOME LINGERING MID LEVEL DEFORMATION
ASSOCIATED WITH THE SHORT WAVE NOW OVER OHIO AND BRIEF MID LEVEL
FGEN PRECEDING A MID LEVEL TROUGH NOW WORKING INTO LAKE MI HAVE BEEN
THE PRIMARY FORCING MECHANISMS DRIVING THIS PRECIP. THERE HAS BEEN
JUST ENOUGH LOW LEVEL COOLING TO SUPPORT A COMPLETE CHANGE OVER TO
SNOW IN MOST LOCALS. STEEP MID LEVEL LAPSE RATES WILL CONTINUE TO
SUPPORT SOME BRIEF BURSTS OF HEAVY SNOW. GIVEN THE SHORT DURATION
AND WITH SFC TEMPS IN THE 30S OVER MOST OF THE FORECAST
AREA...ADDITIONAL SNOW ACCUMS PRIOR TO THE END OF THE PRECIP SHOULD
REMAIN A HALF INCH OR LESS.

LARGE SCALE SUBSIDENCE WITHIN THE DESCENDING BRANCH OF THE MID LEVEL
FRONTAL CIRCULATION WILL OVERSPREAD SE MI EARLY THIS EVENING. THIS
WILL SUSTAIN A DEEP LOW LEVEL INVERSION...HOLDING AMPLE LOW CLOUDS
OVER THE REGION. A POTENT NORTHERN STREAM MID LEVEL TROUGH HAS BEEN
TRACKING ACROSS NRN ONTARIO THIS AFTERNOON. THIS WAVE WILL CONTINUE
TO ADVANCE TO THE SOUTHEAST TONIGHT...MOVING ACROSS SE MI DURING THE
FIRST HALF OF THE OVERNIGHT PERIOD. THIS WILL DRIVE AN ARCTIC COLD
FRONT ACROSS THE FORECAST AREA DURING THE 03Z TO 06Z TIME FRAME.
PRIOR TO THE ARRIVAL OF THIS FRONT...LIMITED COLD AIR ADVECTION WILL
HOLD TEMPS IN THE LOW 30S EARLY THIS EVENING. 925MB TEMPS ARE THEN
FORECAST TO PLUNGE TO -18C BY DAYBREAK FRI IN THE WAKE OF THE COLD
FRONT. THIS WILL CAUSE SFC TEMPS TO DROP TOWARD THE LOW TEENS/UPPER
SINGLE DIGITS. THE COLD AIR WILL BE DRIVEN INTO THE AREA VIA STRONG
W-NW WINDS. WHILE THE SFC ISSALOBARIC COMPONENT WILL BE RATHER
WEAK...A PUSH OF GOOD SYSTEM RELATIVE ISENTROPIC DESCENT TRAILING
THE MID LEVEL WAVE AND STEEPENING LOW LEVEL LAPSE RATES WILL BRING
SOME STRONGER WIND GUSTS TO THE SFC. RECENT MODEL SOUNDINGS WOULD
SUPPORT A FEW GUSTS TOPPING 30 MPH OVERNIGHT. WIND CHILLS WILL IN
TURN BE DRIVEN DOWN TO THE SINGLE DIGITS AND SUB ZERO READINGS BY
EARLY FRI MORNING.

ALTHOUGH THERE WILL BE GOOD LARGE SCALE ASCENT LATE THIS EVENING
PRECEDING THE MID LEVEL WAVE...THE LACK OF MOISTURE ABOVE THE
INVERSION WILL LIMIT SNOWFALL POTENTIAL. LAKE CONTRIBUTION INTO SE
MI WILL ALSO BE LIMITED BY THE MEAN NW WIND TRAJECTORIES. THUS JUST
SOME FLURRIES OR LIGHT SNOW SHOWERS LOOK POSSIBLE /MAINLY ALONG THE
LEAD PUSH OF LOW LEVEL ASCENT ALONG THE ARCTIC FRONT/.

LONG TERM...

HEALTHY SHOT OF ARCTIC AIR IN PLACE TO START THE DAY ON
FRIDAY...WITH 925 MB TEMPS ADVERTISED TO BE IN THE NEGATIVE UPPER
TEENS. THE LOW LEVEL COLD ADVECTION WILL BE EXHAUSTED DURING THE
DAY...AS FLOW WEAKENS AND UPPER LEVEL RIDGE BUILDS OVER THE WESTERN
GREAT LAKES LATE IN THE DAY. NAM SOUNDINGS INDICATING
SUPERSATURATION WITH RESPECT TO ICE BETWEEN 1000-2000 FOOT
LAYER...ENOUGH FOR MENTION OF A FLURRY OR TWO.
HOWEVER...FLOW WILL BE NORTHWEST-NORTH...UNFAVORABLE FOR ANY LAKE
FEED (EXCEPT FOR EASTERN THUMB SHORELINE WHERE MAIN LAKE BAND WILL
HAVE TO BE WATCHED)...WITH DOWN SLOPING COMPONENT INTO MUCH OF
SOUTHEAST MICHIGAN. WILL THUS ALLOW FOR GOOD SHARE OF
SUNSHINE...ALLOWING MAXES TO REACH INTO THE MID TEENS TO AROUND 20
DEGREES...WHICH IS STILL OVER 10 DEGREES BELOW
NORMAL.

SEVERAL KEY FEATURES TO FOCUS ON FOR THE WEEKEND FORECAST.
THE FIRST ONE BEING THE INTENSE CYCLONE OFF THE NEW ENGLAND COAST
FRIDAY NIGHT. THIS SYSTEM IS SLOW TO EXIT...AND THUS BECOMES MERGED
WITH NEXT STRONG UPPER LEVEL TROUGH SWINGING THROUGH ONTARIO ON
SATURDAY. THE FAILURE OF THIS SYSTEM TO CLEAR EASTERN CANADA IN
TIMELY MANNER LIKELY CONTRIBUTING TO SUPPRESSING/DELAYING THE
AMPLIFICATION OF THE SYSTEM COMING OUT OF THE CENTRAL/SOUTHERN
PLAINS FOR THE SECOND HALF OF THE WEEKEND. THAT SYSTEM IS RELYING ON
THE INTERACTION OF AT LEAST TWO UPPER WAVES...ONE ZIPPING OUT OUT OF
THE GULF OF ALASKA AND THE OTHER BEING THE UPPER LEVEL LOW OFF THE
COAST OF BAJA CALIFORNIA. THAT SOUTHERN SYSTEM IS AWFUL FAR TO THE
SOUTH AND OFFSHORE...WITH ONLY A PIECE OF ENERGY EXPECTED TO BREAK
OFF AND INTERACT WITH NORTHERN STREAM WAVE. AS SUCH...MODEL
CONSENSUS (GFS/NAM) IS FOR UPPER LEVEL WESTERN CONFLUENT FLOW AND
HIGH PRESSURE BUILDING UNDERNEATH TO WIN OUT OVER MUCH OF GREAT
LAKES REGION ON SUNDAY...AS EVEN 12Z CANADIAN HAS ABANDONED SHIP
FROM ITS 00Z RUN. STILL...UNTIL THE WAVE OVER THE GULF OF ALASKA
FULLY COMES ONSHORE AND MAGNITUDE IS RESOLVED...WILL NOT RULE OUT
LIGHT ACCUMULATING SNOW ALL TOGETHER FOR SUNDAY JUST YET...SEE 12Z
EURO/NAVGEM...BUT CHANCES ARE CERTAINLY HIGHEST TOWARD THE OHIO
BORDER WHERE WILL CARRY A 50 POP. A NORTHEAST COMPONENT OFF LAKE
HURON MAY ALSO BE SUFFICIENT TO GENERATE SOME LAKE EFFECT SNOW
SHOWERS...BUT OVERALL DRY AIRMASS (SURFACE DEW PTS OF -20 TO -30 F
NEAR GEORGIAN BAY) AND LOW INVERSION HEIGHTS WILL BE TOUGH TO
OVERCOME.

THE LOW WILL BE IN THE PROCESS OF LIFTING OFF TO THE NORTHEAST
TOWARDS THE EAST COAST OVERNIGHT SUNDAY INTO EARLY MONDAY.  THINGS
SETTLE DOWN ON MONDAY AS HIGH PRESSURE BUILDS IN...HOWEVER LOOKING
AT TEMPS ONLY TOPPING OFF IN THE TEENS FOR HIGHS ON MONDAY.  THE
NEXT ACTIVE PERIOD RETURNS TO THE AREA IN THE TUESDAY/WEDNESDAY
TIMEFRAME AS ANOTHER POTENTIAL CLIPPER MOVES IN.

MARINE...

LOW PRESSURE EXITING THE CENTRAL GREAT LAKES THIS AFTERNOON...WITH
QUICK RAMP UP TO NORTHWEST GALES EXPECTED BY EARLY THIS EVENING AS
AIRTIC AIRMASS STREAMS INTO THE AREA. CONFIDENCE IS HIGH IN GALES
FOR MAJORITY OF LAKE HURON WITH LAKE INDUCED TROUGHING ENHANCING THE
FLOW...ALONG WITH WINDS BECOMING NORTHWEST-NORTH INCREASING THE
FETCH. LARGE AREA OF HIGH PRESSURE WILL SLOWLY BUILD EAST INTO THE
ENTIRE GREAT LAKES REGION ON FRIDAY...ALLOWING WINDS TO BECOME LIGHT
LATE IN THE DAY INTO FRIDAY NIGHT. A WEAK LOW WILL TRACK ACROSS THE
NORTHERN GREAT LAKES ON SATURDAY...LEADING TO MODERATE SOUTHWEST
FLOW OVER CENTRAL LAKE HURON AHEAD OF IT. WINDS WILL THEN SWING
AROUND TO THE NORTHWEST AND VEER AROUND TO THE NORTHEAST AS WE HEAD
INTO SUNDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST FRIDAY FOR LHZ362-363-
     441-462>464.

     GALE WARNING UNTIL 10 AM EST FRIDAY FOR LHZ362-363-421-441>443-
     462>464.

     HEAVY FREEZING SPRAY WARNING UNTIL 4 AM EST FRIDAY FOR LHZ361.

     GALE WARNING UNTIL 4 AM EST FRIDAY FOR LHZ361.

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

$$

AVIATION.....KURIMSKI
UPDATE.......KURIMSKI
SHORT TERM...SC
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 300453
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1153 PM EST THU JAN 29 2015


.AVIATION...

SHALLOW COLD AIR ADVECTION UNDER A DEEP LOW LEVEL INVERSION WILL
SUSTAIN MVFR CIGS AND GUSTY WINDS...POSSIBLY GUSTING TO 30 KNOTS AT
TIMES...OVERNIGHT. HIGH PRESSURE BUILDING IN ACROSS TEH WESTERN
GREAT LAKES ON FRIDAY WILL CLEAR OUT THE CEILINGS FRIDAY
MORNING...WITH LIGHTER WINDS EXPECTED BY THE AFTERNOON AS THE
PRESSURE GRADIENT LOOSENS.

FOR DTW...CIGS AROUND 3000 FT ARE EXPECTED THROUGH FRIDAY MORNING
WHEN HIGH PRESSURE BRINGS DRIER AIR IN OVER THE CENTRAL GREAT LAKES.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT OVERNIGHT.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS OVERNIGHT.

&&

.PREV DISCUSSION...ISSUED 806 PM EST THU JAN 29 2015

UPDATE...

LARGE SCALE SUBSIDENCE BEHIND A DEPARTING COLD FRONT HAS BROUGHT
AN END TO THE SNOW SHOWERS ACROSS SOUTHEAST MICHIGAN EARLY THIS
EVENING...WITH ONLY SOME LIGHT SNOW SHOWERS OR FLURRIES EXPECTED
THE REST OF THE NIGHT WITH NO ADDITIONAL ACCUMULATIONS. SNOWFALL
ACCUMULATIONS THIS AFTERNOON AND EARLY THIS EVENING CAME IN AT
ABOUT 1 TO 1.5 INCHES FROM DETROIT NORTHWARD. WHILE THE FRONT HAS
BROUGHT AN END TO THE SNOW...IT HAS BROUGHT A MARKED INCREASE IN
WIND SPEEDS WITH NORTHWESTERLY WINDS GUSTING TO 20 TO 30 MPH. A
SECONDARY COLD FRONT WILL SEND TEMPERATURES PLUMMETING LATER
TONIGHT AS WIND SPEEDS INCREASE FURTHER TO AROUND 30 MPH. THE
COMBINATION OF COLD AND WIND WILL SEND WIND CHILLS DOWN BELOW ZERO
LATE TONIGHT.

PREV DISCUSSION...ISSUED 254 PM EST THU JAN 29 2015

SHORT TERM...LATE THIS AFTERNOON AND TONIGHT

THE BACK EDGE OF THE PRECIPITATION SHIELD WILL CONTINUE ON AN
EASTWARD TRACK LATE THIS AFTERNOON...ADVANCING ACROSS SE MI OVER THE
NEXT TWO TO THREE HOURS. SOME LINGERING MID LEVEL DEFORMATION
ASSOCIATED WITH THE SHORT WAVE NOW OVER OHIO AND BRIEF MID LEVEL
FGEN PRECEDING A MID LEVEL TROUGH NOW WORKING INTO LAKE MI HAVE BEEN
THE PRIMARY FORCING MECHANISMS DRIVING THIS PRECIP. THERE HAS BEEN
JUST ENOUGH LOW LEVEL COOLING TO SUPPORT A COMPLETE CHANGE OVER TO
SNOW IN MOST LOCALS. STEEP MID LEVEL LAPSE RATES WILL CONTINUE TO
SUPPORT SOME BRIEF BURSTS OF HEAVY SNOW. GIVEN THE SHORT DURATION
AND WITH SFC TEMPS IN THE 30S OVER MOST OF THE FORECAST
AREA...ADDITIONAL SNOW ACCUMS PRIOR TO THE END OF THE PRECIP SHOULD
REMAIN A HALF INCH OR LESS.

LARGE SCALE SUBSIDENCE WITHIN THE DESCENDING BRANCH OF THE MID LEVEL
FRONTAL CIRCULATION WILL OVERSPREAD SE MI EARLY THIS EVENING. THIS
WILL SUSTAIN A DEEP LOW LEVEL INVERSION...HOLDING AMPLE LOW CLOUDS
OVER THE REGION. A POTENT NORTHERN STREAM MID LEVEL TROUGH HAS BEEN
TRACKING ACROSS NRN ONTARIO THIS AFTERNOON. THIS WAVE WILL CONTINUE
TO ADVANCE TO THE SOUTHEAST TONIGHT...MOVING ACROSS SE MI DURING THE
FIRST HALF OF THE OVERNIGHT PERIOD. THIS WILL DRIVE AN ARCTIC COLD
FRONT ACROSS THE FORECAST AREA DURING THE 03Z TO 06Z TIME FRAME.
PRIOR TO THE ARRIVAL OF THIS FRONT...LIMITED COLD AIR ADVECTION WILL
HOLD TEMPS IN THE LOW 30S EARLY THIS EVENING. 925MB TEMPS ARE THEN
FORECAST TO PLUNGE TO -18C BY DAYBREAK FRI IN THE WAKE OF THE COLD
FRONT. THIS WILL CAUSE SFC TEMPS TO DROP TOWARD THE LOW TEENS/UPPER
SINGLE DIGITS. THE COLD AIR WILL BE DRIVEN INTO THE AREA VIA STRONG
W-NW WINDS. WHILE THE SFC ISSALOBARIC COMPONENT WILL BE RATHER
WEAK...A PUSH OF GOOD SYSTEM RELATIVE ISENTROPIC DESCENT TRAILING
THE MID LEVEL WAVE AND STEEPENING LOW LEVEL LAPSE RATES WILL BRING
SOME STRONGER WIND GUSTS TO THE SFC. RECENT MODEL SOUNDINGS WOULD
SUPPORT A FEW GUSTS TOPPING 30 MPH OVERNIGHT. WIND CHILLS WILL IN
TURN BE DRIVEN DOWN TO THE SINGLE DIGITS AND SUB ZERO READINGS BY
EARLY FRI MORNING.

ALTHOUGH THERE WILL BE GOOD LARGE SCALE ASCENT LATE THIS EVENING
PRECEDING THE MID LEVEL WAVE...THE LACK OF MOISTURE ABOVE THE
INVERSION WILL LIMIT SNOWFALL POTENTIAL. LAKE CONTRIBUTION INTO SE
MI WILL ALSO BE LIMITED BY THE MEAN NW WIND TRAJECTORIES. THUS JUST
SOME FLURRIES OR LIGHT SNOW SHOWERS LOOK POSSIBLE /MAINLY ALONG THE
LEAD PUSH OF LOW LEVEL ASCENT ALONG THE ARCTIC FRONT/.

LONG TERM...

HEALTHY SHOT OF ARCTIC AIR IN PLACE TO START THE DAY ON
FRIDAY...WITH 925 MB TEMPS ADVERTISED TO BE IN THE NEGATIVE UPPER
TEENS. THE LOW LEVEL COLD ADVECTION WILL BE EXHAUSTED DURING THE
DAY...AS FLOW WEAKENS AND UPPER LEVEL RIDGE BUILDS OVER THE WESTERN
GREAT LAKES LATE IN THE DAY. NAM SOUNDINGS INDICATING
SUPERSATURATION WITH RESPECT TO ICE BETWEEN 1000-2000 FOOT
LAYER...ENOUGH FOR MENTION OF A FLURRY OR TWO.
HOWEVER...FLOW WILL BE NORTHWEST-NORTH...UNFAVORABLE FOR ANY LAKE
FEED (EXCEPT FOR EASTERN THUMB SHORELINE WHERE MAIN LAKE BAND WILL
HAVE TO BE WATCHED)...WITH DOWN SLOPING COMPONENT INTO MUCH OF
SOUTHEAST MICHIGAN. WILL THUS ALLOW FOR GOOD SHARE OF
SUNSHINE...ALLOWING MAXES TO REACH INTO THE MID TEENS TO AROUND 20
DEGREES...WHICH IS STILL OVER 10 DEGREES BELOW
NORMAL.

SEVERAL KEY FEATURES TO FOCUS ON FOR THE WEEKEND FORECAST.
THE FIRST ONE BEING THE INTENSE CYCLONE OFF THE NEW ENGLAND COAST
FRIDAY NIGHT. THIS SYSTEM IS SLOW TO EXIT...AND THUS BECOMES MERGED
WITH NEXT STRONG UPPER LEVEL TROUGH SWINGING THROUGH ONTARIO ON
SATURDAY. THE FAILURE OF THIS SYSTEM TO CLEAR EASTERN CANADA IN
TIMELY MANNER LIKELY CONTRIBUTING TO SUPPRESSING/DELAYING THE
AMPLIFICATION OF THE SYSTEM COMING OUT OF THE CENTRAL/SOUTHERN
PLAINS FOR THE SECOND HALF OF THE WEEKEND. THAT SYSTEM IS RELYING ON
THE INTERACTION OF AT LEAST TWO UPPER WAVES...ONE ZIPPING OUT OUT OF
THE GULF OF ALASKA AND THE OTHER BEING THE UPPER LEVEL LOW OFF THE
COAST OF BAJA CALIFORNIA. THAT SOUTHERN SYSTEM IS AWFUL FAR TO THE
SOUTH AND OFFSHORE...WITH ONLY A PIECE OF ENERGY EXPECTED TO BREAK
OFF AND INTERACT WITH NORTHERN STREAM WAVE. AS SUCH...MODEL
CONSENSUS (GFS/NAM) IS FOR UPPER LEVEL WESTERN CONFLUENT FLOW AND
HIGH PRESSURE BUILDING UNDERNEATH TO WIN OUT OVER MUCH OF GREAT
LAKES REGION ON SUNDAY...AS EVEN 12Z CANADIAN HAS ABANDONED SHIP
FROM ITS 00Z RUN. STILL...UNTIL THE WAVE OVER THE GULF OF ALASKA
FULLY COMES ONSHORE AND MAGNITUDE IS RESOLVED...WILL NOT RULE OUT
LIGHT ACCUMULATING SNOW ALL TOGETHER FOR SUNDAY JUST YET...SEE 12Z
EURO/NAVGEM...BUT CHANCES ARE CERTAINLY HIGHEST TOWARD THE OHIO
BORDER WHERE WILL CARRY A 50 POP. A NORTHEAST COMPONENT OFF LAKE
HURON MAY ALSO BE SUFFICIENT TO GENERATE SOME LAKE EFFECT SNOW
SHOWERS...BUT OVERALL DRY AIRMASS (SURFACE DEW PTS OF -20 TO -30 F
NEAR GEORGIAN BAY) AND LOW INVERSION HEIGHTS WILL BE TOUGH TO
OVERCOME.

THE LOW WILL BE IN THE PROCESS OF LIFTING OFF TO THE NORTHEAST
TOWARDS THE EAST COAST OVERNIGHT SUNDAY INTO EARLY MONDAY.  THINGS
SETTLE DOWN ON MONDAY AS HIGH PRESSURE BUILDS IN...HOWEVER LOOKING
AT TEMPS ONLY TOPPING OFF IN THE TEENS FOR HIGHS ON MONDAY.  THE
NEXT ACTIVE PERIOD RETURNS TO THE AREA IN THE TUESDAY/WEDNESDAY
TIMEFRAME AS ANOTHER POTENTIAL CLIPPER MOVES IN.

MARINE...

LOW PRESSURE EXITING THE CENTRAL GREAT LAKES THIS AFTERNOON...WITH
QUICK RAMP UP TO NORTHWEST GALES EXPECTED BY EARLY THIS EVENING AS
AIRTIC AIRMASS STREAMS INTO THE AREA. CONFIDENCE IS HIGH IN GALES
FOR MAJORITY OF LAKE HURON WITH LAKE INDUCED TROUGHING ENHANCING THE
FLOW...ALONG WITH WINDS BECOMING NORTHWEST-NORTH INCREASING THE
FETCH. LARGE AREA OF HIGH PRESSURE WILL SLOWLY BUILD EAST INTO THE
ENTIRE GREAT LAKES REGION ON FRIDAY...ALLOWING WINDS TO BECOME LIGHT
LATE IN THE DAY INTO FRIDAY NIGHT. A WEAK LOW WILL TRACK ACROSS THE
NORTHERN GREAT LAKES ON SATURDAY...LEADING TO MODERATE SOUTHWEST
FLOW OVER CENTRAL LAKE HURON AHEAD OF IT. WINDS WILL THEN SWING
AROUND TO THE NORTHWEST AND VEER AROUND TO THE NORTHEAST AS WE HEAD
INTO SUNDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST FRIDAY FOR LHZ362-363-
     441-462>464.

     GALE WARNING UNTIL 10 AM EST FRIDAY FOR LHZ362-363-421-441>443-
     462>464.

     HEAVY FREEZING SPRAY WARNING UNTIL 4 AM EST FRIDAY FOR LHZ361.

     GALE WARNING UNTIL 4 AM EST FRIDAY FOR LHZ361.

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

$$

AVIATION.....KURIMSKI
UPDATE.......KURIMSKI
SHORT TERM...SC
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 300106
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
806 PM EST THU JAN 29 2015

.UPDATE...

LARGE SCALE SUBSIDENCE BEHIND A DEPARTING COLD FRONT HAS BROUGHT
AN END TO THE SNOW SHOWERS ACROSS SOUTHEAST MICHIGAN EARLY THIS
EVENING...WITH ONLY SOME LIGHT SNOW SHOWERS OR FLURRIES EXPECTED
THE REST OF THE NIGHT WITH NO ADDITIONAL ACCUMULATIONS. SNOWFALL
ACCUMULATIONS THIS AFTERNOON AND EARLY THIS EVENING CAME IN AT
ABOUT 1 TO 1.5 INCHES FROM DETROIT NORTHWARD. WHILE THE FRONT HAS
BROUGHT AN END TO THE SNOW...IT HAS BROUGHT A MARKED INCREASE IN
WIND SPEEDS WITH NORTHWESTERLY WINDS GUSTING TO 20 TO 30 MPH. A
SECONDARY COLD FRONT WILL SEND TEMPERATURES PLUMMETING LATER
TONIGHT AS WIND SPEEDS INCREASE FURTHER TO AROUND 30 MPH. THE
COMBINATION OF COLD AND WIND WILL SEND WIND CHILLS DOWN BELOW ZERO
LATE TONIGHT.

&&

.AVIATION...ISSUED 618 PM EST THU JAN 29 2015

SNOWFALL HAS PRETTY MUCH ENDED AT ALL OF THE TERMINAL SITES THIS
EVENING WITH LINGERING LIGHT SNOW SHOWERS/FLURRIES EXPECTED DURING
THE OVERNIGHT HOURS WITH NO ADDITIONAL ACCUMULATIONS. SHALLOW COLD
AIR ADVECTION UNDER A DEEP LOW LEVEL INVERSION WILL SUSTAIN MVFR
CIGS THROUGH WELL INTO THE OVERNIGHT. A SECONDARY COLD
FRONT...MARKED BY A PUSH OF ARCTIC AIR WILL ARRIVE LATE THIS EVENING
AND WILL CAUSE A DRAMATIC INCREASE IN THE WINDS /POSSIBLY GUSTING UP
TO 30 KNOTS AT TIMES/. HIGH PRESSURE BUILDING IN ACROSS TEH WESTERN
GREAT LAKES ON FRIDAY WILL CLEAR OUT THE CEILINGS FRIDAY
MORNING...WITH LIGHTER WINDS EXPECTED BY THE AFTERNOON AS THE
PRESSURE GRADIENT LOOSENS.

FOR DTW...MVFR CIGS ARE EXPECTED THROUGH FRIDAY MORNING WHEN HIGH
PRESSURE BRINGS DRIER AIR IN OVER THE CENTRAL GREAT LAKES.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT TONIGHT.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS TONIGHT.

&&

.PREV DISCUSSION...ISSUED 254 PM EST THU JAN 29 2015

SHORT TERM...LATE THIS AFTERNOON AND TONIGHT

THE BACK EDGE OF THE PRECIPITATION SHIELD WILL CONTINUE ON AN
EASTWARD TRACK LATE THIS AFTERNOON...ADVANCING ACROSS SE MI OVER THE
NEXT TWO TO THREE HOURS. SOME LINGERING MID LEVEL DEFORMATION
ASSOCIATED WITH THE SHORT WAVE NOW OVER OHIO AND BRIEF MID LEVEL
FGEN PRECEDING A MID LEVEL TROUGH NOW WORKING INTO LAKE MI HAVE BEEN
THE PRIMARY FORCING MECHANISMS DRIVING THIS PRECIP. THERE HAS BEEN
JUST ENOUGH LOW LEVEL COOLING TO SUPPORT A COMPLETE CHANGE OVER TO
SNOW IN MOST LOCALS. STEEP MID LEVEL LAPSE RATES WILL CONTINUE TO
SUPPORT SOME BRIEF BURSTS OF HEAVY SNOW. GIVEN THE SHORT DURATION
AND WITH SFC TEMPS IN THE 30S OVER MOST OF THE FORECAST
AREA...ADDITIONAL SNOW ACCUMS PRIOR TO THE END OF THE PRECIP SHOULD
REMAIN A HALF INCH OR LESS.

LARGE SCALE SUBSIDENCE WITHIN THE DESCENDING BRANCH OF THE MID LEVEL
FRONTAL CIRCULATION WILL OVERSPREAD SE MI EARLY THIS EVENING. THIS
WILL SUSTAIN A DEEP LOW LEVEL INVERSION...HOLDING AMPLE LOW CLOUDS
OVER THE REGION. A POTENT NORTHERN STREAM MID LEVEL TROUGH HAS BEEN
TRACKING ACROSS NRN ONTARIO THIS AFTERNOON. THIS WAVE WILL CONTINUE
TO ADVANCE TO THE SOUTHEAST TONIGHT...MOVING ACROSS SE MI DURING THE
FIRST HALF OF THE OVERNIGHT PERIOD. THIS WILL DRIVE AN ARCTIC COLD
FRONT ACROSS THE FORECAST AREA DURING THE 03Z TO 06Z TIME FRAME.
PRIOR TO THE ARRIVAL OF THIS FRONT...LIMITED COLD AIR ADVECTION WILL
HOLD TEMPS IN THE LOW 30S EARLY THIS EVENING. 925MB TEMPS ARE THEN
FORECAST TO PLUNGE TO -18C BY DAYBREAK FRI IN THE WAKE OF THE COLD
FRONT. THIS WILL CAUSE SFC TEMPS TO DROP TOWARD THE LOW TEENS/UPPER
SINGLE DIGITS. THE COLD AIR WILL BE DRIVEN INTO THE AREA VIA STRONG
W-NW WINDS. WHILE THE SFC ISSALOBARIC COMPONENT WILL BE RATHER
WEAK...A PUSH OF GOOD SYSTEM RELATIVE ISENTROPIC DESCENT TRAILING
THE MID LEVEL WAVE AND STEEPENING LOW LEVEL LAPSE RATES WILL BRING
SOME STRONGER WIND GUSTS TO THE SFC. RECENT MODEL SOUNDINGS WOULD
SUPPORT A FEW GUSTS TOPPING 30 MPH OVERNIGHT. WIND CHILLS WILL IN
TURN BE DRIVEN DOWN TO THE SINGLE DIGITS AND SUB ZERO READINGS BY
EARLY FRI MORNING.

ALTHOUGH THERE WILL BE GOOD LARGE SCALE ASCENT LATE THIS EVENING
PRECEDING THE MID LEVEL WAVE...THE LACK OF MOISTURE ABOVE THE
INVERSION WILL LIMIT SNOWFALL POTENTIAL. LAKE CONTRIBUTION INTO SE
MI WILL ALSO BE LIMITED BY THE MEAN NW WIND TRAJECTORIES. THUS JUST
SOME FLURRIES OR LIGHT SNOW SHOWERS LOOK POSSIBLE /MAINLY ALONG THE
LEAD PUSH OF LOW LEVEL ASCENT ALONG THE ARCTIC FRONT/.

LONG TERM...

HEALTHY SHOT OF ARCTIC AIR IN PLACE TO START THE DAY ON
FRIDAY...WITH 925 MB TEMPS ADVERTISED TO BE IN THE NEGATIVE UPPER
TEENS. THE LOW LEVEL COLD ADVECTION WILL BE EXHAUSTED DURING THE
DAY...AS FLOW WEAKENS AND UPPER LEVEL RIDGE BUILDS OVER THE WESTERN
GREAT LAKES LATE IN THE DAY. NAM SOUNDINGS INDICATING
SUPERSATURATION WITH RESPECT TO ICE BETWEEN 1000-2000 FOOT
LAYER...ENOUGH FOR MENTION OF A FLURRY OR TWO.
HOWEVER...FLOW WILL BE NORTHWEST-NORTH...UNFAVORABLE FOR ANY LAKE
FEED (EXCEPT FOR EASTERN THUMB SHORELINE WHERE MAIN LAKE BAND WILL
HAVE TO BE WATCHED)...WITH DOWN SLOPING COMPONENT INTO MUCH OF
SOUTHEAST MICHIGAN. WILL THUS ALLOW FOR GOOD SHARE OF
SUNSHINE...ALLOWING MAXES TO REACH INTO THE MID TEENS TO AROUND 20
DEGREES...WHICH IS STILL OVER 10 DEGREES BELOW
NORMAL.

SEVERAL KEY FEATURES TO FOCUS ON FOR THE WEEKEND FORECAST.
THE FIRST ONE BEING THE INTENSE CYCLONE OFF THE NEW ENGLAND COAST
FRIDAY NIGHT. THIS SYSTEM IS SLOW TO EXIT...AND THUS BECOMES MERGED
WITH NEXT STRONG UPPER LEVEL TROUGH SWINGING THROUGH ONTARIO ON
SATURDAY. THE FAILURE OF THIS SYSTEM TO CLEAR EASTERN CANADA IN
TIMELY MANNER LIKELY CONTRIBUTING TO SUPPRESSING/DELAYING THE
AMPLIFICATION OF THE SYSTEM COMING OUT OF THE CENTRAL/SOUTHERN
PLAINS FOR THE SECOND HALF OF THE WEEKEND. THAT SYSTEM IS RELYING ON
THE INTERACTION OF AT LEAST TWO UPPER WAVES...ONE ZIPPING OUT OUT OF
THE GULF OF ALASKA AND THE OTHER BEING THE UPPER LEVEL LOW OFF THE
COAST OF BAJA CALIFORNIA. THAT SOUTHERN SYSTEM IS AWFUL FAR TO THE
SOUTH AND OFFSHORE...WITH ONLY A PIECE OF ENERGY EXPECTED TO BREAK
OFF AND INTERACT WITH NORTHERN STREAM WAVE. AS SUCH...MODEL
CONSENSUS (GFS/NAM) IS FOR UPPER LEVEL WESTERN CONFLUENT FLOW AND
HIGH PRESSURE BUILDING UNDERNEATH TO WIN OUT OVER MUCH OF GREAT
LAKES REGION ON SUNDAY...AS EVEN 12Z CANADIAN HAS ABANDONED SHIP
FROM ITS 00Z RUN. STILL...UNTIL THE WAVE OVER THE GULF OF ALASKA
FULLY COMES ONSHORE AND MAGNITUDE IS RESOLVED...WILL NOT RULE OUT
LIGHT ACCUMULATING SNOW ALL TOGETHER FOR SUNDAY JUST YET...SEE 12Z
EURO/NAVGEM...BUT CHANCES ARE CERTAINLY HIGHEST TOWARD THE OHIO
BORDER WHERE WILL CARRY A 50 POP. A NORTHEAST COMPONENT OFF LAKE
HURON MAY ALSO BE SUFFICIENT TO GENERATE SOME LAKE EFFECT SNOW
SHOWERS...BUT OVERALL DRY AIRMASS (SURFACE DEW PTS OF -20 TO -30 F
NEAR GEORGIAN BAY) AND LOW INVERSION HEIGHTS WILL BE TOUGH TO
OVERCOME.

THE LOW WILL BE IN THE PROCESS OF LIFTING OFF TO THE NORTHEAST
TOWARDS THE EAST COAST OVERNIGHT SUNDAY INTO EARLY MONDAY.  THINGS
SETTLE DOWN ON MONDAY AS HIGH PRESSURE BUILDS IN...HOWEVER LOOKING
AT TEMPS ONLY TOPPING OFF IN THE TEENS FOR HIGHS ON MONDAY.  THE
NEXT ACTIVE PERIOD RETURNS TO THE AREA IN THE TUESDAY/WEDNESDAY
TIMEFRAME AS ANOTHER POTENTIAL CLIPPER MOVES IN.

MARINE...

LOW PRESSURE EXITING THE CENTRAL GREAT LAKES THIS AFTERNOON...WITH
QUICK RAMP UP TO NORTHWEST GALES EXPECTED BY EARLY THIS EVENING AS
AIRTIC AIRMASS STREAMS INTO THE AREA. CONFIDENCE IS HIGH IN GALES
FOR MAJORITY OF LAKE HURON WITH LAKE INDUCED TROUGHING ENHANCING THE
FLOW...ALONG WITH WINDS BECOMING NORTHWEST-NORTH INCREASING THE
FETCH. LARGE AREA OF HIGH PRESSURE WILL SLOWLY BUILD EAST INTO THE
ENTIRE GREAT LAKES REGION ON FRIDAY...ALLOWING WINDS TO BECOME LIGHT
LATE IN THE DAY INTO FRIDAY NIGHT. A WEAK LOW WILL TRACK ACROSS THE
NORTHERN GREAT LAKES ON SATURDAY...LEADING TO MODERATE SOUTHWEST
FLOW OVER CENTRAL LAKE HURON AHEAD OF IT. WINDS WILL THEN SWING
AROUND TO THE NORTHWEST AND VEER AROUND TO THE NORTHEAST AS WE HEAD
INTO SUNDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST FRIDAY FOR LHZ362-363-
     441-462.

     GALE WARNING UNTIL 10 AM EST FRIDAY FOR LHZ362-363-421-441-462.

     HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST FRIDAY FOR LHZ463-464.

     GALE WARNING UNTIL 10 AM EST FRIDAY FOR LHZ442-443-463-464.

     HEAVY FREEZING SPRAY WARNING UNTIL 4 AM EST FRIDAY FOR LHZ361.

     GALE WARNING UNTIL 4 AM EST FRIDAY FOR LHZ361.

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

$$

UPDATE.......KURIMSKI
AVIATION.....KURIMSKI
SHORT TERM...SC
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 300106
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
806 PM EST THU JAN 29 2015

.UPDATE...

LARGE SCALE SUBSIDENCE BEHIND A DEPARTING COLD FRONT HAS BROUGHT
AN END TO THE SNOW SHOWERS ACROSS SOUTHEAST MICHIGAN EARLY THIS
EVENING...WITH ONLY SOME LIGHT SNOW SHOWERS OR FLURRIES EXPECTED
THE REST OF THE NIGHT WITH NO ADDITIONAL ACCUMULATIONS. SNOWFALL
ACCUMULATIONS THIS AFTERNOON AND EARLY THIS EVENING CAME IN AT
ABOUT 1 TO 1.5 INCHES FROM DETROIT NORTHWARD. WHILE THE FRONT HAS
BROUGHT AN END TO THE SNOW...IT HAS BROUGHT A MARKED INCREASE IN
WIND SPEEDS WITH NORTHWESTERLY WINDS GUSTING TO 20 TO 30 MPH. A
SECONDARY COLD FRONT WILL SEND TEMPERATURES PLUMMETING LATER
TONIGHT AS WIND SPEEDS INCREASE FURTHER TO AROUND 30 MPH. THE
COMBINATION OF COLD AND WIND WILL SEND WIND CHILLS DOWN BELOW ZERO
LATE TONIGHT.

&&

.AVIATION...ISSUED 618 PM EST THU JAN 29 2015

SNOWFALL HAS PRETTY MUCH ENDED AT ALL OF THE TERMINAL SITES THIS
EVENING WITH LINGERING LIGHT SNOW SHOWERS/FLURRIES EXPECTED DURING
THE OVERNIGHT HOURS WITH NO ADDITIONAL ACCUMULATIONS. SHALLOW COLD
AIR ADVECTION UNDER A DEEP LOW LEVEL INVERSION WILL SUSTAIN MVFR
CIGS THROUGH WELL INTO THE OVERNIGHT. A SECONDARY COLD
FRONT...MARKED BY A PUSH OF ARCTIC AIR WILL ARRIVE LATE THIS EVENING
AND WILL CAUSE A DRAMATIC INCREASE IN THE WINDS /POSSIBLY GUSTING UP
TO 30 KNOTS AT TIMES/. HIGH PRESSURE BUILDING IN ACROSS TEH WESTERN
GREAT LAKES ON FRIDAY WILL CLEAR OUT THE CEILINGS FRIDAY
MORNING...WITH LIGHTER WINDS EXPECTED BY THE AFTERNOON AS THE
PRESSURE GRADIENT LOOSENS.

FOR DTW...MVFR CIGS ARE EXPECTED THROUGH FRIDAY MORNING WHEN HIGH
PRESSURE BRINGS DRIER AIR IN OVER THE CENTRAL GREAT LAKES.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT TONIGHT.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS TONIGHT.

&&

.PREV DISCUSSION...ISSUED 254 PM EST THU JAN 29 2015

SHORT TERM...LATE THIS AFTERNOON AND TONIGHT

THE BACK EDGE OF THE PRECIPITATION SHIELD WILL CONTINUE ON AN
EASTWARD TRACK LATE THIS AFTERNOON...ADVANCING ACROSS SE MI OVER THE
NEXT TWO TO THREE HOURS. SOME LINGERING MID LEVEL DEFORMATION
ASSOCIATED WITH THE SHORT WAVE NOW OVER OHIO AND BRIEF MID LEVEL
FGEN PRECEDING A MID LEVEL TROUGH NOW WORKING INTO LAKE MI HAVE BEEN
THE PRIMARY FORCING MECHANISMS DRIVING THIS PRECIP. THERE HAS BEEN
JUST ENOUGH LOW LEVEL COOLING TO SUPPORT A COMPLETE CHANGE OVER TO
SNOW IN MOST LOCALS. STEEP MID LEVEL LAPSE RATES WILL CONTINUE TO
SUPPORT SOME BRIEF BURSTS OF HEAVY SNOW. GIVEN THE SHORT DURATION
AND WITH SFC TEMPS IN THE 30S OVER MOST OF THE FORECAST
AREA...ADDITIONAL SNOW ACCUMS PRIOR TO THE END OF THE PRECIP SHOULD
REMAIN A HALF INCH OR LESS.

LARGE SCALE SUBSIDENCE WITHIN THE DESCENDING BRANCH OF THE MID LEVEL
FRONTAL CIRCULATION WILL OVERSPREAD SE MI EARLY THIS EVENING. THIS
WILL SUSTAIN A DEEP LOW LEVEL INVERSION...HOLDING AMPLE LOW CLOUDS
OVER THE REGION. A POTENT NORTHERN STREAM MID LEVEL TROUGH HAS BEEN
TRACKING ACROSS NRN ONTARIO THIS AFTERNOON. THIS WAVE WILL CONTINUE
TO ADVANCE TO THE SOUTHEAST TONIGHT...MOVING ACROSS SE MI DURING THE
FIRST HALF OF THE OVERNIGHT PERIOD. THIS WILL DRIVE AN ARCTIC COLD
FRONT ACROSS THE FORECAST AREA DURING THE 03Z TO 06Z TIME FRAME.
PRIOR TO THE ARRIVAL OF THIS FRONT...LIMITED COLD AIR ADVECTION WILL
HOLD TEMPS IN THE LOW 30S EARLY THIS EVENING. 925MB TEMPS ARE THEN
FORECAST TO PLUNGE TO -18C BY DAYBREAK FRI IN THE WAKE OF THE COLD
FRONT. THIS WILL CAUSE SFC TEMPS TO DROP TOWARD THE LOW TEENS/UPPER
SINGLE DIGITS. THE COLD AIR WILL BE DRIVEN INTO THE AREA VIA STRONG
W-NW WINDS. WHILE THE SFC ISSALOBARIC COMPONENT WILL BE RATHER
WEAK...A PUSH OF GOOD SYSTEM RELATIVE ISENTROPIC DESCENT TRAILING
THE MID LEVEL WAVE AND STEEPENING LOW LEVEL LAPSE RATES WILL BRING
SOME STRONGER WIND GUSTS TO THE SFC. RECENT MODEL SOUNDINGS WOULD
SUPPORT A FEW GUSTS TOPPING 30 MPH OVERNIGHT. WIND CHILLS WILL IN
TURN BE DRIVEN DOWN TO THE SINGLE DIGITS AND SUB ZERO READINGS BY
EARLY FRI MORNING.

ALTHOUGH THERE WILL BE GOOD LARGE SCALE ASCENT LATE THIS EVENING
PRECEDING THE MID LEVEL WAVE...THE LACK OF MOISTURE ABOVE THE
INVERSION WILL LIMIT SNOWFALL POTENTIAL. LAKE CONTRIBUTION INTO SE
MI WILL ALSO BE LIMITED BY THE MEAN NW WIND TRAJECTORIES. THUS JUST
SOME FLURRIES OR LIGHT SNOW SHOWERS LOOK POSSIBLE /MAINLY ALONG THE
LEAD PUSH OF LOW LEVEL ASCENT ALONG THE ARCTIC FRONT/.

LONG TERM...

HEALTHY SHOT OF ARCTIC AIR IN PLACE TO START THE DAY ON
FRIDAY...WITH 925 MB TEMPS ADVERTISED TO BE IN THE NEGATIVE UPPER
TEENS. THE LOW LEVEL COLD ADVECTION WILL BE EXHAUSTED DURING THE
DAY...AS FLOW WEAKENS AND UPPER LEVEL RIDGE BUILDS OVER THE WESTERN
GREAT LAKES LATE IN THE DAY. NAM SOUNDINGS INDICATING
SUPERSATURATION WITH RESPECT TO ICE BETWEEN 1000-2000 FOOT
LAYER...ENOUGH FOR MENTION OF A FLURRY OR TWO.
HOWEVER...FLOW WILL BE NORTHWEST-NORTH...UNFAVORABLE FOR ANY LAKE
FEED (EXCEPT FOR EASTERN THUMB SHORELINE WHERE MAIN LAKE BAND WILL
HAVE TO BE WATCHED)...WITH DOWN SLOPING COMPONENT INTO MUCH OF
SOUTHEAST MICHIGAN. WILL THUS ALLOW FOR GOOD SHARE OF
SUNSHINE...ALLOWING MAXES TO REACH INTO THE MID TEENS TO AROUND 20
DEGREES...WHICH IS STILL OVER 10 DEGREES BELOW
NORMAL.

SEVERAL KEY FEATURES TO FOCUS ON FOR THE WEEKEND FORECAST.
THE FIRST ONE BEING THE INTENSE CYCLONE OFF THE NEW ENGLAND COAST
FRIDAY NIGHT. THIS SYSTEM IS SLOW TO EXIT...AND THUS BECOMES MERGED
WITH NEXT STRONG UPPER LEVEL TROUGH SWINGING THROUGH ONTARIO ON
SATURDAY. THE FAILURE OF THIS SYSTEM TO CLEAR EASTERN CANADA IN
TIMELY MANNER LIKELY CONTRIBUTING TO SUPPRESSING/DELAYING THE
AMPLIFICATION OF THE SYSTEM COMING OUT OF THE CENTRAL/SOUTHERN
PLAINS FOR THE SECOND HALF OF THE WEEKEND. THAT SYSTEM IS RELYING ON
THE INTERACTION OF AT LEAST TWO UPPER WAVES...ONE ZIPPING OUT OUT OF
THE GULF OF ALASKA AND THE OTHER BEING THE UPPER LEVEL LOW OFF THE
COAST OF BAJA CALIFORNIA. THAT SOUTHERN SYSTEM IS AWFUL FAR TO THE
SOUTH AND OFFSHORE...WITH ONLY A PIECE OF ENERGY EXPECTED TO BREAK
OFF AND INTERACT WITH NORTHERN STREAM WAVE. AS SUCH...MODEL
CONSENSUS (GFS/NAM) IS FOR UPPER LEVEL WESTERN CONFLUENT FLOW AND
HIGH PRESSURE BUILDING UNDERNEATH TO WIN OUT OVER MUCH OF GREAT
LAKES REGION ON SUNDAY...AS EVEN 12Z CANADIAN HAS ABANDONED SHIP
FROM ITS 00Z RUN. STILL...UNTIL THE WAVE OVER THE GULF OF ALASKA
FULLY COMES ONSHORE AND MAGNITUDE IS RESOLVED...WILL NOT RULE OUT
LIGHT ACCUMULATING SNOW ALL TOGETHER FOR SUNDAY JUST YET...SEE 12Z
EURO/NAVGEM...BUT CHANCES ARE CERTAINLY HIGHEST TOWARD THE OHIO
BORDER WHERE WILL CARRY A 50 POP. A NORTHEAST COMPONENT OFF LAKE
HURON MAY ALSO BE SUFFICIENT TO GENERATE SOME LAKE EFFECT SNOW
SHOWERS...BUT OVERALL DRY AIRMASS (SURFACE DEW PTS OF -20 TO -30 F
NEAR GEORGIAN BAY) AND LOW INVERSION HEIGHTS WILL BE TOUGH TO
OVERCOME.

THE LOW WILL BE IN THE PROCESS OF LIFTING OFF TO THE NORTHEAST
TOWARDS THE EAST COAST OVERNIGHT SUNDAY INTO EARLY MONDAY.  THINGS
SETTLE DOWN ON MONDAY AS HIGH PRESSURE BUILDS IN...HOWEVER LOOKING
AT TEMPS ONLY TOPPING OFF IN THE TEENS FOR HIGHS ON MONDAY.  THE
NEXT ACTIVE PERIOD RETURNS TO THE AREA IN THE TUESDAY/WEDNESDAY
TIMEFRAME AS ANOTHER POTENTIAL CLIPPER MOVES IN.

MARINE...

LOW PRESSURE EXITING THE CENTRAL GREAT LAKES THIS AFTERNOON...WITH
QUICK RAMP UP TO NORTHWEST GALES EXPECTED BY EARLY THIS EVENING AS
AIRTIC AIRMASS STREAMS INTO THE AREA. CONFIDENCE IS HIGH IN GALES
FOR MAJORITY OF LAKE HURON WITH LAKE INDUCED TROUGHING ENHANCING THE
FLOW...ALONG WITH WINDS BECOMING NORTHWEST-NORTH INCREASING THE
FETCH. LARGE AREA OF HIGH PRESSURE WILL SLOWLY BUILD EAST INTO THE
ENTIRE GREAT LAKES REGION ON FRIDAY...ALLOWING WINDS TO BECOME LIGHT
LATE IN THE DAY INTO FRIDAY NIGHT. A WEAK LOW WILL TRACK ACROSS THE
NORTHERN GREAT LAKES ON SATURDAY...LEADING TO MODERATE SOUTHWEST
FLOW OVER CENTRAL LAKE HURON AHEAD OF IT. WINDS WILL THEN SWING
AROUND TO THE NORTHWEST AND VEER AROUND TO THE NORTHEAST AS WE HEAD
INTO SUNDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST FRIDAY FOR LHZ362-363-
     441-462.

     GALE WARNING UNTIL 10 AM EST FRIDAY FOR LHZ362-363-421-441-462.

     HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST FRIDAY FOR LHZ463-464.

     GALE WARNING UNTIL 10 AM EST FRIDAY FOR LHZ442-443-463-464.

     HEAVY FREEZING SPRAY WARNING UNTIL 4 AM EST FRIDAY FOR LHZ361.

     GALE WARNING UNTIL 4 AM EST FRIDAY FOR LHZ361.

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

$$

UPDATE.......KURIMSKI
AVIATION.....KURIMSKI
SHORT TERM...SC
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 292318
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
618 PM EST THU JAN 29 2015


.AVIATION...

SNOWFALL HAS PRETTY MUCH ENDED AT ALL OF THE TERMINAL SITES THIS
EVENING WITH LINGERING LIGHT SNOW SHOWERS/FLURRIES EXPECTED DURING
THE OVERNIGHT HOURS WITH NO ADDITIONAL ACCUMULATIONS. SHALLOW COLD
AIR ADVECTION UNDER A DEEP LOW LEVEL INVERSION WILL SUSTAIN MVFR
CIGS THROUGH WELL INTO THE OVERNIGHT. A SECONDARY COLD
FRONT...MARKED BY A PUSH OF ARCTIC AIR WILL ARRIVE LATE THIS EVENING
AND WILL CAUSE A DRAMATIC INCREASE IN THE WINDS /POSSIBLY GUSTING UP
TO 30 KNOTS AT TIMES/. HIGH PRESSURE BUILDING IN ACROSS TEH WESTERN
GREAT LAKES ON FRIDAY WILL CLEAR OUT THE CEILINGS FRIDAY
MORNING...WITH LIGHTER WINDS EXPECTED BY THE AFTERNOON AS THE
PRESSURE GRADIENT LOOSENS.

FOR DTW...MVFR CIGS ARE EXPECTED THROUGH FRIDAY MORNING WHEN HIGH
PRESSURE BRINGS DRIER AIR IN OVER THE CENTRAL GREAT LAKES.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT TONIGHT.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS TONIGHT.

&&

.PREV DISCUSSION...ISSUED 254 PM EST THU JAN 29 2015

SHORT TERM...LATE THIS AFTERNOON AND TONIGHT

THE BACK EDGE OF THE PRECIPITATION SHIELD WILL CONTINUE ON AN
EASTWARD TRACK LATE THIS AFTERNOON...ADVANCING ACROSS SE MI OVER THE
NEXT TWO TO THREE HOURS. SOME LINGERING MID LEVEL DEFORMATION
ASSOCIATED WITH THE SHORT WAVE NOW OVER OHIO AND BRIEF MID LEVEL
FGEN PRECEDING A MID LEVEL TROUGH NOW WORKING INTO LAKE MI HAVE BEEN
THE PRIMARY FORCING MECHANISMS DRIVING THIS PRECIP. THERE HAS BEEN
JUST ENOUGH LOW LEVEL COOLING TO SUPPORT A COMPLETE CHANGE OVER TO
SNOW IN MOST LOCALS. STEEP MID LEVEL LAPSE RATES WILL CONTINUE TO
SUPPORT SOME BRIEF BURSTS OF HEAVY SNOW. GIVEN THE SHORT DURATION
AND WITH SFC TEMPS IN THE 30S OVER MOST OF THE FORECAST
AREA...ADDITIONAL SNOW ACCUMS PRIOR TO THE END OF THE PRECIP SHOULD
REMAIN A HALF INCH OR LESS.

LARGE SCALE SUBSIDENCE WITHIN THE DESCENDING BRANCH OF THE MID LEVEL
FRONTAL CIRCULATION WILL OVERSPREAD SE MI EARLY THIS EVENING. THIS
WILL SUSTAIN A DEEP LOW LEVEL INVERSION...HOLDING AMPLE LOW CLOUDS
OVER THE REGION. A POTENT NORTHERN STREAM MID LEVEL TROUGH HAS BEEN
TRACKING ACROSS NRN ONTARIO THIS AFTERNOON. THIS WAVE WILL CONTINUE
TO ADVANCE TO THE SOUTHEAST TONIGHT...MOVING ACROSS SE MI DURING THE
FIRST HALF OF THE OVERNIGHT PERIOD. THIS WILL DRIVE AN ARCTIC COLD
FRONT ACROSS THE FORECAST AREA DURING THE 03Z TO 06Z TIME FRAME.
PRIOR TO THE ARRIVAL OF THIS FRONT...LIMITED COLD AIR ADVECTION WILL
HOLD TEMPS IN THE LOW 30S EARLY THIS EVENING. 925MB TEMPS ARE THEN
FORECAST TO PLUNGE TO -18C BY DAYBREAK FRI IN THE WAKE OF THE COLD
FRONT. THIS WILL CAUSE SFC TEMPS TO DROP TOWARD THE LOW TEENS/UPPER
SINGLE DIGITS. THE COLD AIR WILL BE DRIVEN INTO THE AREA VIA STRONG
W-NW WINDS. WHILE THE SFC ISSALOBARIC COMPONENT WILL BE RATHER
WEAK...A PUSH OF GOOD SYSTEM RELATIVE ISENTROPIC DESCENT TRAILING
THE MID LEVEL WAVE AND STEEPENING LOW LEVEL LAPSE RATES WILL BRING
SOME STRONGER WIND GUSTS TO THE SFC. RECENT MODEL SOUNDINGS WOULD
SUPPORT A FEW GUSTS TOPPING 30 MPH OVERNIGHT. WIND CHILLS WILL IN
TURN BE DRIVEN DOWN TO THE SINGLE DIGITS AND SUB ZERO READINGS BY
EARLY FRI MORNING.

ALTHOUGH THERE WILL BE GOOD LARGE SCALE ASCENT LATE THIS EVENING
PRECEDING THE MID LEVEL WAVE...THE LACK OF MOISTURE ABOVE THE
INVERSION WILL LIMIT SNOWFALL POTENTIAL. LAKE CONTRIBUTION INTO SE
MI WILL ALSO BE LIMITED BY THE MEAN NW WIND TRAJECTORIES. THUS JUST
SOME FLURRIES OR LIGHT SNOW SHOWERS LOOK POSSIBLE /MAINLY ALONG THE
LEAD PUSH OF LOW LEVEL ASCENT ALONG THE ARCTIC FRONT/.

LONG TERM...

HEALTHY SHOT OF ARCTIC AIR IN PLACE TO START THE DAY ON
FRIDAY...WITH 925 MB TEMPS ADVERTISED TO BE IN THE NEGATIVE UPPER
TEENS. THE LOW LEVEL COLD ADVECTION WILL BE EXHAUSTED DURING THE
DAY...AS FLOW WEAKENS AND UPPER LEVEL RIDGE BUILDS OVER THE WESTERN
GREAT LAKES LATE IN THE DAY. NAM SOUNDINGS INDICATING
SUPERSATURATION WITH RESPECT TO ICE BETWEEN 1000-2000 FOOT
LAYER...ENOUGH FOR MENTION OF A FLURRY OR TWO.
HOWEVER...FLOW WILL BE NORTHWEST-NORTH...UNFAVORABLE FOR ANY LAKE
FEED (EXCEPT FOR EASTERN THUMB SHORELINE WHERE MAIN LAKE BAND WILL
HAVE TO BE WATCHED)...WITH DOWN SLOPING COMPONENT INTO MUCH OF
SOUTHEAST MICHIGAN. WILL THUS ALLOW FOR GOOD SHARE OF
SUNSHINE...ALLOWING MAXES TO REACH INTO THE MID TEENS TO AROUND 20
DEGREES...WHICH IS STILL OVER 10 DEGREES BELOW
NORMAL.

SEVERAL KEY FEATURES TO FOCUS ON FOR THE WEEKEND FORECAST.
THE FIRST ONE BEING THE INTENSE CYCLONE OFF THE NEW ENGLAND COAST
FRIDAY NIGHT. THIS SYSTEM IS SLOW TO EXIT...AND THUS BECOMES MERGED
WITH NEXT STRONG UPPER LEVEL TROUGH SWINGING THROUGH ONTARIO ON
SATURDAY. THE FAILURE OF THIS SYSTEM TO CLEAR EASTERN CANADA IN
TIMELY MANNER LIKELY CONTRIBUTING TO SUPPRESSING/DELAYING THE
AMPLIFICATION OF THE SYSTEM COMING OUT OF THE CENTRAL/SOUTHERN
PLAINS FOR THE SECOND HALF OF THE WEEKEND. THAT SYSTEM IS RELYING ON
THE INTERACTION OF AT LEAST TWO UPPER WAVES...ONE ZIPPING OUT OUT OF
THE GULF OF ALASKA AND THE OTHER BEING THE UPPER LEVEL LOW OFF THE
COAST OF BAJA CALIFORNIA. THAT SOUTHERN SYSTEM IS AWFUL FAR TO THE
SOUTH AND OFFSHORE...WITH ONLY A PIECE OF ENERGY EXPECTED TO BREAK
OFF AND INTERACT WITH NORTHERN STREAM WAVE. AS SUCH...MODEL
CONSENSUS (GFS/NAM) IS FOR UPPER LEVEL WESTERN CONFLUENT FLOW AND
HIGH PRESSURE BUILDING UNDERNEATH TO WIN OUT OVER MUCH OF GREAT
LAKES REGION ON SUNDAY...AS EVEN 12Z CANADIAN HAS ABANDONED SHIP
FROM ITS 00Z RUN. STILL...UNTIL THE WAVE OVER THE GULF OF ALASKA
FULLY COMES ONSHORE AND MAGNITUDE IS RESOLVED...WILL NOT RULE OUT
LIGHT ACCUMULATING SNOW ALL TOGETHER FOR SUNDAY JUST YET...SEE 12Z
EURO/NAVGEM...BUT CHANCES ARE CERTAINLY HIGHEST TOWARD THE OHIO
BORDER WHERE WILL CARRY A 50 POP. A NORTHEAST COMPONENT OFF LAKE
HURON MAY ALSO BE SUFFICIENT TO GENERATE SOME LAKE EFFECT SNOW
SHOWERS...BUT OVERALL DRY AIRMASS (SURFACE DEW PTS OF -20 TO -30 F
NEAR GEORGIAN BAY) AND LOW INVERSION HEIGHTS WILL BE TOUGH TO
OVERCOME.

THE LOW WILL BE IN THE PROCESS OF LIFTING OFF TO THE NORTHEAST
TOWARDS THE EAST COAST OVERNIGHT SUNDAY INTO EARLY MONDAY.  THINGS
SETTLE DOWN ON MONDAY AS HIGH PRESSURE BUILDS IN...HOWEVER LOOKING
AT TEMPS ONLY TOPPING OFF IN THE TEENS FOR HIGHS ON MONDAY.  THE
NEXT ACTIVE PERIOD RETURNS TO THE AREA IN THE TUESDAY/WEDNESDAY
TIMEFRAME AS ANOTHER POTENTIAL CLIPPER MOVES IN.

MARINE...

LOW PRESSURE EXITING THE CENTRAL GREAT LAKES THIS AFTERNOON...WITH
QUICK RAMP UP TO NORTHWEST GALES EXPECTED BY EARLY THIS EVENING AS
AIRTIC AIRMASS STREAMS INTO THE AREA. CONFIDENCE IS HIGH IN GALES
FOR MAJORITY OF LAKE HURON WITH LAKE INDUCED TROUGHING ENHANCING THE
FLOW...ALONG WITH WINDS BECOMING NORTHWEST-NORTH INCREASING THE
FETCH. LARGE AREA OF HIGH PRESSURE WILL SLOWLY BUILD EAST INTO THE
ENTIRE GREAT LAKES REGION ON FRIDAY...ALLOWING WINDS TO BECOME LIGHT
LATE IN THE DAY INTO FRIDAY NIGHT. A WEAK LOW WILL TRACK ACROSS THE
NORTHERN GREAT LAKES ON SATURDAY...LEADING TO MODERATE SOUTHWEST
FLOW OVER CENTRAL LAKE HURON AHEAD OF IT. WINDS WILL THEN SWING
AROUND TO THE NORTHWEST AND VEER AROUND TO THE NORTHEAST AS WE HEAD
INTO SUNDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST FRIDAY FOR LHZ362-363-
     441-462.

     GALE WARNING UNTIL 10 AM EST FRIDAY FOR LHZ362-363-421-441-462.

     HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     FRIDAY FOR LHZ463-464.

     GALE WARNING FROM 10 PM THIS EVENING TO 10 AM EST FRIDAY FOR LHZ442-
     443-463-464.

     HEAVY FREEZING SPRAY WARNING UNTIL 4 AM EST FRIDAY FOR LHZ361.

     GALE WARNING UNTIL 4 AM EST FRIDAY FOR LHZ361.

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

$$

AVIATION.....KURIMSKI
SHORT TERM...SC
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 292318
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
618 PM EST THU JAN 29 2015


.AVIATION...

SNOWFALL HAS PRETTY MUCH ENDED AT ALL OF THE TERMINAL SITES THIS
EVENING WITH LINGERING LIGHT SNOW SHOWERS/FLURRIES EXPECTED DURING
THE OVERNIGHT HOURS WITH NO ADDITIONAL ACCUMULATIONS. SHALLOW COLD
AIR ADVECTION UNDER A DEEP LOW LEVEL INVERSION WILL SUSTAIN MVFR
CIGS THROUGH WELL INTO THE OVERNIGHT. A SECONDARY COLD
FRONT...MARKED BY A PUSH OF ARCTIC AIR WILL ARRIVE LATE THIS EVENING
AND WILL CAUSE A DRAMATIC INCREASE IN THE WINDS /POSSIBLY GUSTING UP
TO 30 KNOTS AT TIMES/. HIGH PRESSURE BUILDING IN ACROSS TEH WESTERN
GREAT LAKES ON FRIDAY WILL CLEAR OUT THE CEILINGS FRIDAY
MORNING...WITH LIGHTER WINDS EXPECTED BY THE AFTERNOON AS THE
PRESSURE GRADIENT LOOSENS.

FOR DTW...MVFR CIGS ARE EXPECTED THROUGH FRIDAY MORNING WHEN HIGH
PRESSURE BRINGS DRIER AIR IN OVER THE CENTRAL GREAT LAKES.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT TONIGHT.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS TONIGHT.

&&

.PREV DISCUSSION...ISSUED 254 PM EST THU JAN 29 2015

SHORT TERM...LATE THIS AFTERNOON AND TONIGHT

THE BACK EDGE OF THE PRECIPITATION SHIELD WILL CONTINUE ON AN
EASTWARD TRACK LATE THIS AFTERNOON...ADVANCING ACROSS SE MI OVER THE
NEXT TWO TO THREE HOURS. SOME LINGERING MID LEVEL DEFORMATION
ASSOCIATED WITH THE SHORT WAVE NOW OVER OHIO AND BRIEF MID LEVEL
FGEN PRECEDING A MID LEVEL TROUGH NOW WORKING INTO LAKE MI HAVE BEEN
THE PRIMARY FORCING MECHANISMS DRIVING THIS PRECIP. THERE HAS BEEN
JUST ENOUGH LOW LEVEL COOLING TO SUPPORT A COMPLETE CHANGE OVER TO
SNOW IN MOST LOCALS. STEEP MID LEVEL LAPSE RATES WILL CONTINUE TO
SUPPORT SOME BRIEF BURSTS OF HEAVY SNOW. GIVEN THE SHORT DURATION
AND WITH SFC TEMPS IN THE 30S OVER MOST OF THE FORECAST
AREA...ADDITIONAL SNOW ACCUMS PRIOR TO THE END OF THE PRECIP SHOULD
REMAIN A HALF INCH OR LESS.

LARGE SCALE SUBSIDENCE WITHIN THE DESCENDING BRANCH OF THE MID LEVEL
FRONTAL CIRCULATION WILL OVERSPREAD SE MI EARLY THIS EVENING. THIS
WILL SUSTAIN A DEEP LOW LEVEL INVERSION...HOLDING AMPLE LOW CLOUDS
OVER THE REGION. A POTENT NORTHERN STREAM MID LEVEL TROUGH HAS BEEN
TRACKING ACROSS NRN ONTARIO THIS AFTERNOON. THIS WAVE WILL CONTINUE
TO ADVANCE TO THE SOUTHEAST TONIGHT...MOVING ACROSS SE MI DURING THE
FIRST HALF OF THE OVERNIGHT PERIOD. THIS WILL DRIVE AN ARCTIC COLD
FRONT ACROSS THE FORECAST AREA DURING THE 03Z TO 06Z TIME FRAME.
PRIOR TO THE ARRIVAL OF THIS FRONT...LIMITED COLD AIR ADVECTION WILL
HOLD TEMPS IN THE LOW 30S EARLY THIS EVENING. 925MB TEMPS ARE THEN
FORECAST TO PLUNGE TO -18C BY DAYBREAK FRI IN THE WAKE OF THE COLD
FRONT. THIS WILL CAUSE SFC TEMPS TO DROP TOWARD THE LOW TEENS/UPPER
SINGLE DIGITS. THE COLD AIR WILL BE DRIVEN INTO THE AREA VIA STRONG
W-NW WINDS. WHILE THE SFC ISSALOBARIC COMPONENT WILL BE RATHER
WEAK...A PUSH OF GOOD SYSTEM RELATIVE ISENTROPIC DESCENT TRAILING
THE MID LEVEL WAVE AND STEEPENING LOW LEVEL LAPSE RATES WILL BRING
SOME STRONGER WIND GUSTS TO THE SFC. RECENT MODEL SOUNDINGS WOULD
SUPPORT A FEW GUSTS TOPPING 30 MPH OVERNIGHT. WIND CHILLS WILL IN
TURN BE DRIVEN DOWN TO THE SINGLE DIGITS AND SUB ZERO READINGS BY
EARLY FRI MORNING.

ALTHOUGH THERE WILL BE GOOD LARGE SCALE ASCENT LATE THIS EVENING
PRECEDING THE MID LEVEL WAVE...THE LACK OF MOISTURE ABOVE THE
INVERSION WILL LIMIT SNOWFALL POTENTIAL. LAKE CONTRIBUTION INTO SE
MI WILL ALSO BE LIMITED BY THE MEAN NW WIND TRAJECTORIES. THUS JUST
SOME FLURRIES OR LIGHT SNOW SHOWERS LOOK POSSIBLE /MAINLY ALONG THE
LEAD PUSH OF LOW LEVEL ASCENT ALONG THE ARCTIC FRONT/.

LONG TERM...

HEALTHY SHOT OF ARCTIC AIR IN PLACE TO START THE DAY ON
FRIDAY...WITH 925 MB TEMPS ADVERTISED TO BE IN THE NEGATIVE UPPER
TEENS. THE LOW LEVEL COLD ADVECTION WILL BE EXHAUSTED DURING THE
DAY...AS FLOW WEAKENS AND UPPER LEVEL RIDGE BUILDS OVER THE WESTERN
GREAT LAKES LATE IN THE DAY. NAM SOUNDINGS INDICATING
SUPERSATURATION WITH RESPECT TO ICE BETWEEN 1000-2000 FOOT
LAYER...ENOUGH FOR MENTION OF A FLURRY OR TWO.
HOWEVER...FLOW WILL BE NORTHWEST-NORTH...UNFAVORABLE FOR ANY LAKE
FEED (EXCEPT FOR EASTERN THUMB SHORELINE WHERE MAIN LAKE BAND WILL
HAVE TO BE WATCHED)...WITH DOWN SLOPING COMPONENT INTO MUCH OF
SOUTHEAST MICHIGAN. WILL THUS ALLOW FOR GOOD SHARE OF
SUNSHINE...ALLOWING MAXES TO REACH INTO THE MID TEENS TO AROUND 20
DEGREES...WHICH IS STILL OVER 10 DEGREES BELOW
NORMAL.

SEVERAL KEY FEATURES TO FOCUS ON FOR THE WEEKEND FORECAST.
THE FIRST ONE BEING THE INTENSE CYCLONE OFF THE NEW ENGLAND COAST
FRIDAY NIGHT. THIS SYSTEM IS SLOW TO EXIT...AND THUS BECOMES MERGED
WITH NEXT STRONG UPPER LEVEL TROUGH SWINGING THROUGH ONTARIO ON
SATURDAY. THE FAILURE OF THIS SYSTEM TO CLEAR EASTERN CANADA IN
TIMELY MANNER LIKELY CONTRIBUTING TO SUPPRESSING/DELAYING THE
AMPLIFICATION OF THE SYSTEM COMING OUT OF THE CENTRAL/SOUTHERN
PLAINS FOR THE SECOND HALF OF THE WEEKEND. THAT SYSTEM IS RELYING ON
THE INTERACTION OF AT LEAST TWO UPPER WAVES...ONE ZIPPING OUT OUT OF
THE GULF OF ALASKA AND THE OTHER BEING THE UPPER LEVEL LOW OFF THE
COAST OF BAJA CALIFORNIA. THAT SOUTHERN SYSTEM IS AWFUL FAR TO THE
SOUTH AND OFFSHORE...WITH ONLY A PIECE OF ENERGY EXPECTED TO BREAK
OFF AND INTERACT WITH NORTHERN STREAM WAVE. AS SUCH...MODEL
CONSENSUS (GFS/NAM) IS FOR UPPER LEVEL WESTERN CONFLUENT FLOW AND
HIGH PRESSURE BUILDING UNDERNEATH TO WIN OUT OVER MUCH OF GREAT
LAKES REGION ON SUNDAY...AS EVEN 12Z CANADIAN HAS ABANDONED SHIP
FROM ITS 00Z RUN. STILL...UNTIL THE WAVE OVER THE GULF OF ALASKA
FULLY COMES ONSHORE AND MAGNITUDE IS RESOLVED...WILL NOT RULE OUT
LIGHT ACCUMULATING SNOW ALL TOGETHER FOR SUNDAY JUST YET...SEE 12Z
EURO/NAVGEM...BUT CHANCES ARE CERTAINLY HIGHEST TOWARD THE OHIO
BORDER WHERE WILL CARRY A 50 POP. A NORTHEAST COMPONENT OFF LAKE
HURON MAY ALSO BE SUFFICIENT TO GENERATE SOME LAKE EFFECT SNOW
SHOWERS...BUT OVERALL DRY AIRMASS (SURFACE DEW PTS OF -20 TO -30 F
NEAR GEORGIAN BAY) AND LOW INVERSION HEIGHTS WILL BE TOUGH TO
OVERCOME.

THE LOW WILL BE IN THE PROCESS OF LIFTING OFF TO THE NORTHEAST
TOWARDS THE EAST COAST OVERNIGHT SUNDAY INTO EARLY MONDAY.  THINGS
SETTLE DOWN ON MONDAY AS HIGH PRESSURE BUILDS IN...HOWEVER LOOKING
AT TEMPS ONLY TOPPING OFF IN THE TEENS FOR HIGHS ON MONDAY.  THE
NEXT ACTIVE PERIOD RETURNS TO THE AREA IN THE TUESDAY/WEDNESDAY
TIMEFRAME AS ANOTHER POTENTIAL CLIPPER MOVES IN.

MARINE...

LOW PRESSURE EXITING THE CENTRAL GREAT LAKES THIS AFTERNOON...WITH
QUICK RAMP UP TO NORTHWEST GALES EXPECTED BY EARLY THIS EVENING AS
AIRTIC AIRMASS STREAMS INTO THE AREA. CONFIDENCE IS HIGH IN GALES
FOR MAJORITY OF LAKE HURON WITH LAKE INDUCED TROUGHING ENHANCING THE
FLOW...ALONG WITH WINDS BECOMING NORTHWEST-NORTH INCREASING THE
FETCH. LARGE AREA OF HIGH PRESSURE WILL SLOWLY BUILD EAST INTO THE
ENTIRE GREAT LAKES REGION ON FRIDAY...ALLOWING WINDS TO BECOME LIGHT
LATE IN THE DAY INTO FRIDAY NIGHT. A WEAK LOW WILL TRACK ACROSS THE
NORTHERN GREAT LAKES ON SATURDAY...LEADING TO MODERATE SOUTHWEST
FLOW OVER CENTRAL LAKE HURON AHEAD OF IT. WINDS WILL THEN SWING
AROUND TO THE NORTHWEST AND VEER AROUND TO THE NORTHEAST AS WE HEAD
INTO SUNDAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST FRIDAY FOR LHZ362-363-
     441-462.

     GALE WARNING UNTIL 10 AM EST FRIDAY FOR LHZ362-363-421-441-462.

     HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     FRIDAY FOR LHZ463-464.

     GALE WARNING FROM 10 PM THIS EVENING TO 10 AM EST FRIDAY FOR LHZ442-
     443-463-464.

     HEAVY FREEZING SPRAY WARNING UNTIL 4 AM EST FRIDAY FOR LHZ361.

     GALE WARNING UNTIL 4 AM EST FRIDAY FOR LHZ361.

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

$$

AVIATION.....KURIMSKI
SHORT TERM...SC
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 291954
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
254 PM EST THU JAN 29 2015

.SHORT TERM...LATE THIS AFTERNOON AND TONIGHT

THE BACK EDGE OF THE PRECIPITATION SHIELD WILL CONTINUE ON AN
EASTWARD TRACK LATE THIS AFTERNOON...ADVANCING ACROSS SE MI OVER THE
NEXT TWO TO THREE HOURS. SOME LINGERING MID LEVEL DEFORMATION
ASSOCIATED WITH THE SHORT WAVE NOW OVER OHIO AND BRIEF MID LEVEL
FGEN PRECEDING A MID LEVEL TROUGH NOW WORKING INTO LAKE MI HAVE BEEN
THE PRIMARY FORCING MECHANISMS DRIVING THIS PRECIP. THERE HAS BEEN
JUST ENOUGH LOW LEVEL COOLING TO SUPPORT A COMPLETE CHANGE OVER TO
SNOW IN MOST LOCALS. STEEP MID LEVEL LAPSE RATES WILL CONTINUE TO
SUPPORT SOME BRIEF BURSTS OF HEAVY SNOW. GIVEN THE SHORT DURATION
AND WITH SFC TEMPS IN THE 30S OVER MOST OF THE FORECAST
AREA...ADDITIONAL SNOW ACCUMS PRIOR TO THE END OF THE PRECIP SHOULD
REMAIN A HALF INCH OR LESS.

LARGE SCALE SUBSIDENCE WITHIN THE DESCENDING BRANCH OF THE MID LEVEL
FRONTAL CIRCULATION WILL OVERSPREAD SE MI EARLY THIS EVENING. THIS
WILL SUSTAIN A DEEP LOW LEVEL INVERSION...HOLDING AMPLE LOW CLOUDS
OVER THE REGION. A POTENT NORTHERN STREAM MID LEVEL TROUGH HAS BEEN
TRACKING ACROSS NRN ONTARIO THIS AFTERNOON. THIS WAVE WILL CONTINUE
TO ADVANCE TO THE SOUTHEAST TONIGHT...MOVING ACROSS SE MI DURING THE
FIRST HALF OF THE OVERNIGHT PERIOD. THIS WILL DRIVE AN ARCTIC COLD
FRONT ACROSS THE FORECAST AREA DURING THE 03Z TO 06Z TIME FRAME.
PRIOR TO THE ARRIVAL OF THIS FRONT...LIMITED COLD AIR ADVECTION WILL
HOLD TEMPS IN THE LOW 30S EARLY THIS EVENING. 925MB TEMPS ARE THEN
FORECAST TO PLUNGE TO -18C BY DAYBREAK FRI IN THE WAKE OF THE COLD
FRONT. THIS WILL CAUSE SFC TEMPS TO DROP TOWARD THE LOW TEENS/UPPER
SINGLE DIGITS. THE COLD AIR WILL BE DRIVEN INTO THE AREA VIA STRONG
W-NW WINDS. WHILE THE SFC ISSALOBARIC COMPONENT WILL BE RATHER
WEAK...A PUSH OF GOOD SYSTEM RELATIVE ISENTROPIC DESCENT TRAILING
THE MID LEVEL WAVE AND STEEPENING LOW LEVEL LAPSE RATES WILL BRING
SOME STRONGER WIND GUSTS TO THE SFC. RECENT MODEL SOUNDINGS WOULD
SUPPORT A FEW GUSTS TOPPING 30 MPH OVERNIGHT. WIND CHILLS WILL IN
TURN BE DRIVEN DOWN TO THE SINGLE DIGITS AND SUB ZERO READINGS BY
EARLY FRI MORNING.

ALTHOUGH THERE WILL BE GOOD LARGE SCALE ASCENT LATE THIS EVENING
PRECEDING THE MID LEVEL WAVE...THE LACK OF MOISTURE ABOVE THE
INVERSION WILL LIMIT SNOWFALL POTENTIAL. LAKE CONTRIBUTION INTO SE
MI WILL ALSO BE LIMITED BY THE MEAN NW WIND TRAJECTORIES. THUS JUST
SOME FLURRIES OR LIGHT SNOW SHOWERS LOOK POSSIBLE /MAINLY ALONG THE
LEAD PUSH OF LOW LEVEL ASCENT ALONG THE ARCTIC FRONT/.

&&

.LONG TERM...

HEALTHY SHOT OF ARCTIC AIR IN PLACE TO START THE DAY ON
FRIDAY...WITH 925 MB TEMPS ADVERTISED TO BE IN THE NEGATIVE UPPER
TEENS. THE LOW LEVEL COLD ADVECTION WILL BE EXHAUSTED DURING THE
DAY...AS FLOW WEAKENS AND UPPER LEVEL RIDGE BUILDS OVER THE WESTERN
GREAT LAKES LATE IN THE DAY. NAM SOUNDINGS INDICATING
SUPERSATURATION WITH RESPECT TO ICE BETWEEN 1000-2000 FOOT
LAYER...ENOUGH FOR MENTION OF A FLURRY OR TWO.
HOWEVER...FLOW WILL BE NORTHWEST-NORTH...UNFAVORABLE FOR ANY LAKE
FEED (EXCEPT FOR EASTERN THUMB SHORELINE WHERE MAIN LAKE BAND WILL
HAVE TO BE WATCHED)...WITH DOWN SLOPING COMPONENT INTO MUCH OF
SOUTHEAST MICHIGAN. WILL THUS ALLOW FOR GOOD SHARE OF
SUNSHINE...ALLOWING MAXES TO REACH INTO THE MID TEENS TO AROUND 20
DEGREES...WHICH IS STILL OVER 10 DEGREES BELOW
NORMAL.

SEVERAL KEY FEATURES TO FOCUS ON FOR THE WEEKEND FORECAST.
THE FIRST ONE BEING THE INTENSE CYCLONE OFF THE NEW ENGLAND COAST
FRIDAY NIGHT. THIS SYSTEM IS SLOW TO EXIT...AND THUS BECOMES MERGED
WITH NEXT STRONG UPPER LEVEL TROUGH SWINGING THROUGH ONTARIO ON
SATURDAY. THE FAILURE OF THIS SYSTEM TO CLEAR EASTERN CANADA IN
TIMELY MANNER LIKELY CONTRIBUTING TO SUPPRESSING/DELAYING THE
AMPLIFICATION OF THE SYSTEM COMING OUT OF THE CENTRAL/SOUTHERN
PLAINS FOR THE SECOND HALF OF THE WEEKEND. THAT SYSTEM IS RELYING ON
THE INTERACTION OF AT LEAST TWO UPPER WAVES...ONE ZIPPING OUT OUT OF
THE GULF OF ALASKA AND THE OTHER BEING THE UPPER LEVEL LOW OFF THE
COAST OF BAJA CALIFORNIA. THAT SOUTHERN SYSTEM IS AWFUL FAR TO THE
SOUTH AND OFFSHORE...WITH ONLY A PIECE OF ENERGY EXPECTED TO BREAK
OFF AND INTERACT WITH NORTHERN STREAM WAVE. AS SUCH...MODEL
CONSENSUS (GFS/NAM) IS FOR UPPER LEVEL WESTERN CONFLUENT FLOW AND
HIGH PRESSURE BUILDING UNDERNEATH TO WIN OUT OVER MUCH OF GREAT
LAKES REGION ON SUNDAY...AS EVEN 12Z CANADIAN HAS ABANDONED SHIP
FROM ITS 00Z RUN. STILL...UNTIL THE WAVE OVER THE GULF OF ALASKA
FULLY COMES ONSHORE AND MAGNITUDE IS RESOLVED...WILL NOT RULE OUT
LIGHT ACCUMULATING SNOW ALL TOGETHER FOR SUNDAY JUST YET...SEE 12Z
EURO/NAVGEM...BUT CHANCES ARE CERTAINLY HIGHEST TOWARD THE OHIO
BORDER WHERE WILL CARRY A 50 POP. A NORTHEAST COMPONENT OFF LAKE
HURON MAY ALSO BE SUFFICIENT TO GENERATE SOME LAKE EFFECT SNOW
SHOWERS...BUT OVERALL DRY AIRMASS (SURFACE DEW PTS OF -20 TO -30 F
NEAR GEORGIAN BAY) AND LOW INVERSION HEIGHTS WILL BE TOUGH TO
OVERCOME.

THE LOW WILL BE IN THE PROCESS OF LIFTING OFF TO THE NORTHEAST
TOWARDS THE EAST COAST OVERNIGHT SUNDAY INTO EARLY MONDAY.  THINGS
SETTLE DOWN ON MONDAY AS HIGH PRESSURE BUILDS IN...HOWEVER LOOKING
AT TEMPS ONLY TOPPING OFF IN THE TEENS FOR HIGHS ON MONDAY.  THE
NEXT ACTIVE PERIOD RETURNS TO THE AREA IN THE TUESDAY/WEDNESDAY
TIMEFRAME AS ANOTHER POTENTIAL CLIPPER MOVES IN.

&&

.MARINE...

LOW PRESSURE EXITING THE CENTRAL GREAT LAKES THIS AFTERNOON...WITH
QUICK RAMP UP TO NORTHWEST GALES EXPECTED BY EARLY THIS EVENING AS
AIRTIC AIRMASS STREAMS INTO THE AREA. CONFIDENCE IS HIGH IN GALES
FOR MAJORITY OF LAKE HURON WITH LAKE INDUCED TROUGHING ENHANCING THE
FLOW...ALONG WITH WINDS BECOMING NORTHWEST-NORTH INCREASING THE
FETCH. LARGE AREA OF HIGH PRESSURE WILL SLOWLY BUILD EAST INTO THE
ENTIRE GREAT LAKES REGION ON FRIDAY...ALLOWING WINDS TO BECOME LIGHT
LATE IN THE DAY INTO FRIDAY NIGHT. A WEAK LOW WILL TRACK ACROSS THE
NORTHERN GREAT LAKES ON SATURDAY...LEADING TO MODERATE SOUTHWEST
FLOW OVER CENTRAL LAKE HURON AHEAD OF IT. WINDS WILL THEN SWING
AROUND TO THE NORTHWEST AND VEER AROUND TO THE NORTHEAST AS WE HEAD
INTO SUNDAY.

&&

.AVIATION...ISSUED 1203 PM EST THU JAN 29 2015

THE REGION OF PRECIP NOW MOVING ACROSS SW MI WILL ADVANCE ACROSS THE
TERMINALS EARLY THIS AFTERNOON. THE BULK OF THIS WILL FALL AS SNOW
FROM PTK NORTH AND RAIN/SNOW SOUTH. THERE IS A DEFINITE BACK EDGE TO
THIS PRECIP /MARKED BY THE END OF LARGER SCALE FORCING/. THIS BACK
EDGE WILL MOVE THROUGH SE MI BETWEEN 20Z AND 22Z. THE ASSOCIATED SFC
LOW WILL PASS EAST OF METRO DETROIT AFTER 19Z CAUSING A VEERING OF
THE WIND TOWARD THE W-NW WITH A MODEST INCREASE IN WIND SPEED.
SHALLOW COLD AIR ADVECTION UNDER A DEEP LOW LEVEL INVERSION WILL
SUSTAIN MVFR CIGS THROUGH WELL INTO THE OVERNIGHT. A SECONDARY COLD
FRONT...MARKED BY A PUSH OF ARCTIC AIR WILL ARRIVE LATE THIS EVENING
AND WILL CAUSE A DRAMATIC INCREASE IN THE WINDS /POSSIBLY GUSTING UP
TO 30 KNOTS AT TIMES/.

FOR DTW...ENOUGH WARM AIR IS IN PLACE OVER METRO DETROIT TO SUPPORT
RAIN MIXED WITH SOME SNOW AS THIS SECOND BATCH OF PRECIP ARRIVES
WITHIN THE NEXT HOUR. SFC TEMPS WILL REMAIN ABOVE FREEZING...SO NO
ACCUMULATIONS WITH ANY SNOW IS EXPECTED.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT THIS AFTERNOON AND TONIGHT.

* MEDIUM IN PRECIPITATION BEING MOSTLY RAIN THIS AFTERNOON.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS TONIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     FRIDAY FOR LHZ362-363-441-462.

     GALE WARNING FROM 7 PM THIS EVENING TO 10 AM EST FRIDAY FOR LHZ362-
     363-421-441-462.

     HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     FRIDAY FOR LHZ463-464.

     GALE WARNING FROM 10 PM THIS EVENING TO 10 AM EST FRIDAY FOR LHZ442-
     443-463-464.

     HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 4 AM EST
     FRIDAY FOR LHZ361.

     GALE WARNING FROM 7 PM THIS EVENING TO 4 AM EST FRIDAY FOR LHZ361.

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

$$

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


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




000
FXUS63 KDTX 291954
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
254 PM EST THU JAN 29 2015

.SHORT TERM...LATE THIS AFTERNOON AND TONIGHT

THE BACK EDGE OF THE PRECIPITATION SHIELD WILL CONTINUE ON AN
EASTWARD TRACK LATE THIS AFTERNOON...ADVANCING ACROSS SE MI OVER THE
NEXT TWO TO THREE HOURS. SOME LINGERING MID LEVEL DEFORMATION
ASSOCIATED WITH THE SHORT WAVE NOW OVER OHIO AND BRIEF MID LEVEL
FGEN PRECEDING A MID LEVEL TROUGH NOW WORKING INTO LAKE MI HAVE BEEN
THE PRIMARY FORCING MECHANISMS DRIVING THIS PRECIP. THERE HAS BEEN
JUST ENOUGH LOW LEVEL COOLING TO SUPPORT A COMPLETE CHANGE OVER TO
SNOW IN MOST LOCALS. STEEP MID LEVEL LAPSE RATES WILL CONTINUE TO
SUPPORT SOME BRIEF BURSTS OF HEAVY SNOW. GIVEN THE SHORT DURATION
AND WITH SFC TEMPS IN THE 30S OVER MOST OF THE FORECAST
AREA...ADDITIONAL SNOW ACCUMS PRIOR TO THE END OF THE PRECIP SHOULD
REMAIN A HALF INCH OR LESS.

LARGE SCALE SUBSIDENCE WITHIN THE DESCENDING BRANCH OF THE MID LEVEL
FRONTAL CIRCULATION WILL OVERSPREAD SE MI EARLY THIS EVENING. THIS
WILL SUSTAIN A DEEP LOW LEVEL INVERSION...HOLDING AMPLE LOW CLOUDS
OVER THE REGION. A POTENT NORTHERN STREAM MID LEVEL TROUGH HAS BEEN
TRACKING ACROSS NRN ONTARIO THIS AFTERNOON. THIS WAVE WILL CONTINUE
TO ADVANCE TO THE SOUTHEAST TONIGHT...MOVING ACROSS SE MI DURING THE
FIRST HALF OF THE OVERNIGHT PERIOD. THIS WILL DRIVE AN ARCTIC COLD
FRONT ACROSS THE FORECAST AREA DURING THE 03Z TO 06Z TIME FRAME.
PRIOR TO THE ARRIVAL OF THIS FRONT...LIMITED COLD AIR ADVECTION WILL
HOLD TEMPS IN THE LOW 30S EARLY THIS EVENING. 925MB TEMPS ARE THEN
FORECAST TO PLUNGE TO -18C BY DAYBREAK FRI IN THE WAKE OF THE COLD
FRONT. THIS WILL CAUSE SFC TEMPS TO DROP TOWARD THE LOW TEENS/UPPER
SINGLE DIGITS. THE COLD AIR WILL BE DRIVEN INTO THE AREA VIA STRONG
W-NW WINDS. WHILE THE SFC ISSALOBARIC COMPONENT WILL BE RATHER
WEAK...A PUSH OF GOOD SYSTEM RELATIVE ISENTROPIC DESCENT TRAILING
THE MID LEVEL WAVE AND STEEPENING LOW LEVEL LAPSE RATES WILL BRING
SOME STRONGER WIND GUSTS TO THE SFC. RECENT MODEL SOUNDINGS WOULD
SUPPORT A FEW GUSTS TOPPING 30 MPH OVERNIGHT. WIND CHILLS WILL IN
TURN BE DRIVEN DOWN TO THE SINGLE DIGITS AND SUB ZERO READINGS BY
EARLY FRI MORNING.

ALTHOUGH THERE WILL BE GOOD LARGE SCALE ASCENT LATE THIS EVENING
PRECEDING THE MID LEVEL WAVE...THE LACK OF MOISTURE ABOVE THE
INVERSION WILL LIMIT SNOWFALL POTENTIAL. LAKE CONTRIBUTION INTO SE
MI WILL ALSO BE LIMITED BY THE MEAN NW WIND TRAJECTORIES. THUS JUST
SOME FLURRIES OR LIGHT SNOW SHOWERS LOOK POSSIBLE /MAINLY ALONG THE
LEAD PUSH OF LOW LEVEL ASCENT ALONG THE ARCTIC FRONT/.

&&

.LONG TERM...

HEALTHY SHOT OF ARCTIC AIR IN PLACE TO START THE DAY ON
FRIDAY...WITH 925 MB TEMPS ADVERTISED TO BE IN THE NEGATIVE UPPER
TEENS. THE LOW LEVEL COLD ADVECTION WILL BE EXHAUSTED DURING THE
DAY...AS FLOW WEAKENS AND UPPER LEVEL RIDGE BUILDS OVER THE WESTERN
GREAT LAKES LATE IN THE DAY. NAM SOUNDINGS INDICATING
SUPERSATURATION WITH RESPECT TO ICE BETWEEN 1000-2000 FOOT
LAYER...ENOUGH FOR MENTION OF A FLURRY OR TWO.
HOWEVER...FLOW WILL BE NORTHWEST-NORTH...UNFAVORABLE FOR ANY LAKE
FEED (EXCEPT FOR EASTERN THUMB SHORELINE WHERE MAIN LAKE BAND WILL
HAVE TO BE WATCHED)...WITH DOWN SLOPING COMPONENT INTO MUCH OF
SOUTHEAST MICHIGAN. WILL THUS ALLOW FOR GOOD SHARE OF
SUNSHINE...ALLOWING MAXES TO REACH INTO THE MID TEENS TO AROUND 20
DEGREES...WHICH IS STILL OVER 10 DEGREES BELOW
NORMAL.

SEVERAL KEY FEATURES TO FOCUS ON FOR THE WEEKEND FORECAST.
THE FIRST ONE BEING THE INTENSE CYCLONE OFF THE NEW ENGLAND COAST
FRIDAY NIGHT. THIS SYSTEM IS SLOW TO EXIT...AND THUS BECOMES MERGED
WITH NEXT STRONG UPPER LEVEL TROUGH SWINGING THROUGH ONTARIO ON
SATURDAY. THE FAILURE OF THIS SYSTEM TO CLEAR EASTERN CANADA IN
TIMELY MANNER LIKELY CONTRIBUTING TO SUPPRESSING/DELAYING THE
AMPLIFICATION OF THE SYSTEM COMING OUT OF THE CENTRAL/SOUTHERN
PLAINS FOR THE SECOND HALF OF THE WEEKEND. THAT SYSTEM IS RELYING ON
THE INTERACTION OF AT LEAST TWO UPPER WAVES...ONE ZIPPING OUT OUT OF
THE GULF OF ALASKA AND THE OTHER BEING THE UPPER LEVEL LOW OFF THE
COAST OF BAJA CALIFORNIA. THAT SOUTHERN SYSTEM IS AWFUL FAR TO THE
SOUTH AND OFFSHORE...WITH ONLY A PIECE OF ENERGY EXPECTED TO BREAK
OFF AND INTERACT WITH NORTHERN STREAM WAVE. AS SUCH...MODEL
CONSENSUS (GFS/NAM) IS FOR UPPER LEVEL WESTERN CONFLUENT FLOW AND
HIGH PRESSURE BUILDING UNDERNEATH TO WIN OUT OVER MUCH OF GREAT
LAKES REGION ON SUNDAY...AS EVEN 12Z CANADIAN HAS ABANDONED SHIP
FROM ITS 00Z RUN. STILL...UNTIL THE WAVE OVER THE GULF OF ALASKA
FULLY COMES ONSHORE AND MAGNITUDE IS RESOLVED...WILL NOT RULE OUT
LIGHT ACCUMULATING SNOW ALL TOGETHER FOR SUNDAY JUST YET...SEE 12Z
EURO/NAVGEM...BUT CHANCES ARE CERTAINLY HIGHEST TOWARD THE OHIO
BORDER WHERE WILL CARRY A 50 POP. A NORTHEAST COMPONENT OFF LAKE
HURON MAY ALSO BE SUFFICIENT TO GENERATE SOME LAKE EFFECT SNOW
SHOWERS...BUT OVERALL DRY AIRMASS (SURFACE DEW PTS OF -20 TO -30 F
NEAR GEORGIAN BAY) AND LOW INVERSION HEIGHTS WILL BE TOUGH TO
OVERCOME.

THE LOW WILL BE IN THE PROCESS OF LIFTING OFF TO THE NORTHEAST
TOWARDS THE EAST COAST OVERNIGHT SUNDAY INTO EARLY MONDAY.  THINGS
SETTLE DOWN ON MONDAY AS HIGH PRESSURE BUILDS IN...HOWEVER LOOKING
AT TEMPS ONLY TOPPING OFF IN THE TEENS FOR HIGHS ON MONDAY.  THE
NEXT ACTIVE PERIOD RETURNS TO THE AREA IN THE TUESDAY/WEDNESDAY
TIMEFRAME AS ANOTHER POTENTIAL CLIPPER MOVES IN.

&&

.MARINE...

LOW PRESSURE EXITING THE CENTRAL GREAT LAKES THIS AFTERNOON...WITH
QUICK RAMP UP TO NORTHWEST GALES EXPECTED BY EARLY THIS EVENING AS
AIRTIC AIRMASS STREAMS INTO THE AREA. CONFIDENCE IS HIGH IN GALES
FOR MAJORITY OF LAKE HURON WITH LAKE INDUCED TROUGHING ENHANCING THE
FLOW...ALONG WITH WINDS BECOMING NORTHWEST-NORTH INCREASING THE
FETCH. LARGE AREA OF HIGH PRESSURE WILL SLOWLY BUILD EAST INTO THE
ENTIRE GREAT LAKES REGION ON FRIDAY...ALLOWING WINDS TO BECOME LIGHT
LATE IN THE DAY INTO FRIDAY NIGHT. A WEAK LOW WILL TRACK ACROSS THE
NORTHERN GREAT LAKES ON SATURDAY...LEADING TO MODERATE SOUTHWEST
FLOW OVER CENTRAL LAKE HURON AHEAD OF IT. WINDS WILL THEN SWING
AROUND TO THE NORTHWEST AND VEER AROUND TO THE NORTHEAST AS WE HEAD
INTO SUNDAY.

&&

.AVIATION...ISSUED 1203 PM EST THU JAN 29 2015

THE REGION OF PRECIP NOW MOVING ACROSS SW MI WILL ADVANCE ACROSS THE
TERMINALS EARLY THIS AFTERNOON. THE BULK OF THIS WILL FALL AS SNOW
FROM PTK NORTH AND RAIN/SNOW SOUTH. THERE IS A DEFINITE BACK EDGE TO
THIS PRECIP /MARKED BY THE END OF LARGER SCALE FORCING/. THIS BACK
EDGE WILL MOVE THROUGH SE MI BETWEEN 20Z AND 22Z. THE ASSOCIATED SFC
LOW WILL PASS EAST OF METRO DETROIT AFTER 19Z CAUSING A VEERING OF
THE WIND TOWARD THE W-NW WITH A MODEST INCREASE IN WIND SPEED.
SHALLOW COLD AIR ADVECTION UNDER A DEEP LOW LEVEL INVERSION WILL
SUSTAIN MVFR CIGS THROUGH WELL INTO THE OVERNIGHT. A SECONDARY COLD
FRONT...MARKED BY A PUSH OF ARCTIC AIR WILL ARRIVE LATE THIS EVENING
AND WILL CAUSE A DRAMATIC INCREASE IN THE WINDS /POSSIBLY GUSTING UP
TO 30 KNOTS AT TIMES/.

FOR DTW...ENOUGH WARM AIR IS IN PLACE OVER METRO DETROIT TO SUPPORT
RAIN MIXED WITH SOME SNOW AS THIS SECOND BATCH OF PRECIP ARRIVES
WITHIN THE NEXT HOUR. SFC TEMPS WILL REMAIN ABOVE FREEZING...SO NO
ACCUMULATIONS WITH ANY SNOW IS EXPECTED.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT THIS AFTERNOON AND TONIGHT.

* MEDIUM IN PRECIPITATION BEING MOSTLY RAIN THIS AFTERNOON.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS TONIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     FRIDAY FOR LHZ362-363-441-462.

     GALE WARNING FROM 7 PM THIS EVENING TO 10 AM EST FRIDAY FOR LHZ362-
     363-421-441-462.

     HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     FRIDAY FOR LHZ463-464.

     GALE WARNING FROM 10 PM THIS EVENING TO 10 AM EST FRIDAY FOR LHZ442-
     443-463-464.

     HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 4 AM EST
     FRIDAY FOR LHZ361.

     GALE WARNING FROM 7 PM THIS EVENING TO 4 AM EST FRIDAY FOR LHZ361.

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

$$

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


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





000
FXUS63 KDTX 291703
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1203 PM EST THU JAN 29 2015


.AVIATION...

THE REGION OF PRECIP NOW MOVING ACROSS SW MI WILL ADVANCE ACROSS THE
TERMINALS EARLY THIS AFTERNOON. THE BULK OF THIS WILL FALL AS SNOW
FROM PTK NORTH AND RAIN/SNOW SOUTH. THERE IS A DEFINITE BACK EDGE TO
THIS PRECIP /MARKED BY THE END OF LARGER SCALE FORCING/. THIS BACK
EDGE WILL MOVE THROUGH SE MI BETWEEN 20Z AND 22Z. THE ASSOCIATED SFC
LOW WILL PASS EAST OF METRO DETROIT AFTER 19Z CAUSING A VEERING OF
THE WIND TOWARD THE W-NW WITH A MODEST INCREASE IN WIND SPEED.
SHALLOW COLD AIR ADVECTION UNDER A DEEP LOW LEVEL INVERSION WILL
SUSTAIN MVFR CIGS THROUGH WELL INTO THE OVERNIGHT. A SECONDARY COLD
FRONT...MARKED BY A PUSH OF ARCTIC AIR WILL ARRIVE LATE THIS EVENING
AND WILL CAUSE A DRAMATIC INCREASE IN THE WINDS /POSSIBLY GUSTING UP
TO 30 KNOTS AT TIMES/.

FOR DTW...ENOUGH WARM AIR IS IN PLACE OVER METRO DETROIT TO SUPPORT
RAIN MIXED WITH SOME SNOW AS THIS SECOND BATCH OF PRECIP ARRIVES
WITHIN THE NEXT HOUR. SFC TEMPS WILL REMAIN ABOVE FREEZING...SO NO
ACCUMULATIONS WITH ANY SNOW IS EXPECTED.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT THIS AFTERNOON AND TONIGHT.

* MEDIUM IN PRECIPITATION BEING MOSTLY RAIN THIS AFTERNOON.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS TONIGHT.

&&

.PREV DISCUSSION...ISSUED 948 AM EST THU JAN 29 2015

UPDATE...

THE WATER VAPOR LOOP THIS MORNING SHOWS A SHORT WAVE NOW TRACKING
ACROSS CNTL INDIANA WITH A MID LEVEL TROUGH AXIS EXTENDING FROM
THE WRN UP INTO SRN MN. THE REGIONAL RADAR DATA SHOWS AN AREA OF
SNOW EXTENDING ACROSS NRN AND CNTL LOWER MI...WITHIN THE REGION OF
MID LEVEL DEFORMATION BETWEEN THESE TWO WAVES. THIS DEFORMATION
FORCING WILL BE DRIVEN ACROSS THE NORTHERN HALF OF THE FORECAST
AREA DURING THE LATER HALF OF THE MORNING INTO EARLY
AFTERNOON...LEADING TO SOME REDEVELOPMENT OF SNOW. FARTHER
SOUTH...RADAR DATA HAS BEEN SHOWING SOME RETURNS ACROSS SOUTHERN
LAKE MI. THESE ARE MORE CONVECTIVE IN NATURE IN LIGHT OF THE STEEP
MID LEVEL LAPSE RATES. THESE SHOWERS ARE OCCURRING WITHIN SOME
ADDITIONAL MID LEVEL DEFORMATION ALONG THE NORTHERN EDGE OF THE
OHIO VALLEY WAVE AND WILL AFFECT THE SOUTHERN HALF OF THE FORECAST
AREA LATE THIS MORNING AND AFTERNOON. THE EASTWARD ADVANCEMENT OF
THESE WAVES WILL ALLOW THE FORCING TO REMAIN PROGRESSIVE TODAY.
THERE MAY BE A BRIEF LULL IN PRECIP THIS AFTERNOON PRIOR TO SOME
ENHANCED MID LEVEL FGEN ARRIVING LATER THIS AFTERNOON AHEAD OF THE
NRN STREAM TROUGH AXIS.

THE ASSOC SFC LOW LOCATED ALONG THE IN/MI BORDER AS OF 14Z...WILL
LIFT INTO SE MI BY EARLY AFTERNOON. TEMPS AHEAD OF THIS LOW HAVE
RISEN INTO THE MID/UPPER 30S. THIS WARMER AIR WILL ADVECT INTO
METRO DETROIT. THE DEPTH OF THE WARM AIR LOOKS SUFFICIENT TO KEEP
PRECIP MAINLY LIQUID THROUGH MID AFTERNOON FOR METRO DETROIT
SOUTH /ALTHOUGH THERE MAY BE SOME BRIEF PERIODS OF SLEET IN ANY
HIGHER INTENSITY CONVECTIVE ELEMENTS/. THE WARM LAYER WILL BE MUCH
MORE SHALLOW FARTHER NORTH...SUPPORTING MAINLY SNOW. ADDITIONAL
SNOW ACCUMULATION OF AN INCH OR TWO WILL BE POSSIBLE ACROSS
MIDLAND/BAY/HURON COUNTIES WHERE FORCING WILL BE A LITTLE
STRONGER/MORE PERSISTENT. ACCUMS FARTHER SOUTH SHOULD BE MINIMAL.
COLDER AIR WILL ARRIVE LATE IN THE AFTERNOON WITH THE PASSAGE OF
THE MID LEVEL FGEN...FAVORING A PRECIP CHANGE OVER TO SNOW. THIS
FORCING LOOKS TO BE VERY BRIEF AND WEAK ENOUGH TO KEEP ACCUMS
MINIMAL IF ANY. AN UPDATED FORECAST WILL BE ISSUED SHORTLY TO
REFLECT THESE LATEST PRECIP TRENDS.

PREV DISCUSSION...ISSUED 242 AM EST THU JAN 29 2015

SHORT TERM...TODAY AND TONIGHT

A SHORTWAVE WILL TRACK FROM THE MID MISSISSIPPI VALLEY INTO THE
CENTRAL GREAT LAKES TODAY...SPREADING MOISTURE INTO THE AREA EARLY
THIS MORNING. 00Z KDTX SOUNDING SHOWS A VERY DRY LAYER IN PLACE OVER
LOWER MICHIGAN FROM 750 MB DOWN TO THE SURFACE...WHICH HAS KEPT A
BAND OF MOISTURE WITHIN REGION OF ISENTROPIC ASCENT IN ADVANCE OF
THIS THE MAIN SYSTEM ELEVATED OVERNIGHT.

FORCING ALONG THE LEAD EDGE OF THE VORTICITY CENTER WILL PROGRESS
EAST TO NORTHEAST INTO THE AREA FROM ITS CURRENTLY POSITION FROM
SOUTHWEST LOWER MICHIGAN INTO NORTHERN INDIANA. HOWEVER...BETWEEN
THE DRY LOW LEVELS STILL IN PLACE IN ADVANCE OF THIS BAND OF RAIN
AND SNOW...AND A MID LEVEL DRY SLOT TRAILING THIS FEATURE INTO THE
AREA...PRECIPITATION INTENSITY AND DURATION WILL BE LIMITED EARLY
THIS MORNING OVER MUCH OF THE CWA. ONLY THE NORTHERN THIRD TO HALF
OF THE CWA MAY RECEIVE 3 OR 4 HOURS OF PRECIPITATION...MAINLY SLEET
OR SNOW...ALONG THE NORTHERN EDGE OF THE DRY SLOT.

FURTHER SOUTH INTO METRO DETROIT AND POINTS SOUTH...A BRIEF ONE OR
TWO HOUR PERIOD OF LIGHT SHOWERS OR SLEET WILL CROSS THE AREA. WITH
TEMPERATURES IN THE MID 20S...ANY LIQUID THAT DOES FALL WILL MOST
LIKELY FREEZE ON SURFACES. AT THIS TIME...ONLY PATCHY SLICK SPOTS
ARE EXPECTED GIVEN THE LACK OF COVERAGE OF THE THE PRECIPITATION.
NO HEADLINES ARE ANTICIPATED AT THIS TIME.

AS THE SHORTWAVE CROSSES THE AREA TODAY...ADDITIONAL SNOW SHOWERS
WILL OCCUR AS COLDER AIR ASSOCIATED WITH THE WAVE OVERSPREADS THE
AREA. TEMPERATURES AT THE SURFACE WILL REMAIN AOA FREEZING FOR MUCH
OF THE AREA FROM LATE MORNING INTO THE AFTERNOON AS STRONGER COLD
AIR ADVECTION HOLDS OFF UNTIL THIS EVENING AND TONIGHT. TOTAL SNOW
ACCUMULATIONS OF AN INCH OR TWO WILL BE POSSIBLE DURING THE ENTIRE
PERIOD OVER THE NORTHERN CWA WITH MUCH LESSER AMOUNTS SOUTHWARD FROM
METRO DETROIT TO THE MICHIGAN AND OHIO STATE LINE.

COLD AIR WILL FILTER BACK SOUTH INTO THE AREA TONIGHT WITH THE LOW
TEMPERATURES RANGING FROM THE SINGLE DIGITS TO AROUND 10 DEGREE OVER
THE NORTH TO THE LOW/MID TEENS I-94 SOUTH. ANY REMAINING SNOW
SHOWERS WILL BE INSIGNIFICANT.

LONG TERM...

ARCTIC HIGH PRESSURE BUTTED AGAINST THE FRONT RANGE OF THE ROCKIES
IN ALBERTA THIS MORNING IS INTENSIFYING AS SHORTWAVE RIDGING
DEVELOPS DOWNSTREAM OF THE ALEUTIAN LOW. COLLAPSE OF UPPER SUPPORT
DUE TO INCREASING CONFLUENCE OVER NORTHWEST CANADA WILL FORCE THE
HIGH TO WEAKEN AND QUICKLY TRANSLATE SOUTHEAST INTO THE UPPER
MIDWEST THIS MORNING BEFORE SETTLING OVER THE OHIO VALLEY TONIGHT.
THIS WILL DRIVE A PERSISTENT NW GRADIENT ACROSS THE CWA THROUGH THE
FIRST HALF OF FRIDAY. COLD ADVECTION WILL EASE AS THE BROAD SURFACE
RIDGE AXIS TRAVERSES THE AREA, BUT WITH 925MB TEMPERATURES HOVERING
NEAR -17C, HIGHS WILL BE STUCK IN THE TEENS ON FRIDAY. RAPID
EASTWARD PROGRESS OF THE HIGH AND DRY NW FLOW, SUPPORTED BY
RELATIVELY DRY MOISTURE FIELDS IN THE 00Z NAM, SUGGEST THAT THIS
WILL BE THE CASE EVEN IN THE PRESENCE OF MOSTLY SUNNY SKIES OVER
MOST OF THE AREA. THE POTENTIAL EXCEPTION MAY BE ACROSS THE FAR NW
WHERE LAKE SUPERIOR-MICHIGAN PLUME WILL POTENTIALLY CONTRIBUTE TO A
MORE PERSISTENT STRATOCU DECK. FOR THIS SAME REASON, LOWS SHOULD
EASILY FALL INTO THE SINGLE DIGITS FRIDAY NIGHT, BUT HAVE A HIGHER
LIKELIHOOD OF REMAINING IN THE 10-15 DEGREES ACROSS THE FAR WEST.

A MOISTURE STARVED WAVE EMBEDDED IN NW FLOW WILL RACE ACROSS THE
GREAT LAKES EARLY FRIDAY BRINGING NOTHING MORE THAN A FEW SNOW
SHOWERS ACROSS THE FAR NORTH WITH NO ACCUMULATION EXPECTED.
DEVELOPING RETURN FLOW WILL PUSH HIGHS INTO AT LEAST THE UPPER 20S.

HIGH UNCERTAINTY FOR THE SECOND HALF OF THE WEEKEND. A SHORTWAVE,
WHICH HAS YET TO ACTUALLY DEVELOP, IS FORECAST BY THE SUITE OF
GUIDANCE TO EMERGE OUT OF THE ALEUTIAN LOW LATE TONIGHT AND COME
ONSHORE IN BRITISH COLUMBIA ON FRIDAY EVENING. THIS WAVE WILL
QUICKLY SHEAR TO SOUTHEAST AND INTERACT TO SOME DEGREE WITH A CLOSED
LOW OVER THE BAJA.

WHAT IS KNOWN IS THAT THERE IS A REASONABLE LIKELIHOOD FOR A
PROLONGED PERIOD OF LIGHT TO MODERATE ACCUMULATING SNOW TO DEVELOP
OVER A WIDE AREA GIVEN GIVEN THE BROAD AREA OF ISENTROPIC ASCENT AND
NORTHWARD TRANSPORT OF 4-5 G/KG H7 SPECIFIC HUMIDITY COURTESY OF
SOUTHERN STREAM INVOLVEMENT. THE KEY PLAYER IN THE LOCAL FORECAST
WILL BE JUST HOW AGGRESSIVELY THE NORTHERN BRANCH DIGS OVER MONTANA,
WYOMING, AND COLORADO SATURDAY INTO SATURDAY NIGHT. THE GREATER THE
INTERACTION WITH THE CLOSED LOW, THE GREATER SNOW PROSPECTS BECOME.
AS IT STANDS, THE NAM AND GEM ARE BY FAR THE MOST AGGRESSIVE. THE
ECMWF AND GFS ARE CONSIDERABLY LESS SO AND CONFINE ACCUMULATING SNOW
SOUTH OF THE OHIO BORDER. HOWEVER, THE LATTER TWO STILL MADE
NOTEWORTHY MOVES TOWARD MORE AGGRESSIVE SOLUTIONS AT 00Z IN
COMPARISON TO THEIR 12Z COUNTERPARTS. 00Z GFS ENSEMBLES ARE SPLIT
BETWEEN NORTH/SOUTH SOLUTIONS WITH THE OPERATIONAL GFS AND TWO
CONTROL RUNS REMAINING RIGHT IN BETWEEN AND CENTERING THE ACTION
ALONG/SOUTH OF I-80. GIVEN THAT THE S/W HAS YET TO EMERGE, TYPICAL
NWP PROBLEMS WITH CLOSED LOWS, AND GENERAL LOW MEDIUM RANGE
PREDICTABILITY THIS WINTER, WILL SIMPLY ALLOW THE BLENDED EXTENDED
GRIDS TO SPEAK FOR THEMSELVES AT THIS POINT.

MARINE...

FRESH TO STRONG SOUTHERLY WINDS WILL PERSIST FOR THE NEXT FEW HOURS
AS A WEAK LOW APPROACHES FROM THE WEST. GUSTS WILL BE LIMITED TO
AROUND 30 KNOTS GIVEN THE STABILITY OF WARM SOUTH FLOW. WINDS WILL
VEER TO THE NORTHWEST AND INCREASE CONSIDERABLY THIS EVENING INTO
TONIGHT. WIDESPREAD GALES ARE EXPECTED OVER LAKE HURON WITH GUSTS TO
STRONG GALES EXPECTED OVER CENTRAL AND SOUTHERN LAKE HURON WHERE
SIGNIFICANT WAVE HEIGHTS WILL EXCEED 12 FEET WITH HIGHER MAXIMUM
WAVE HEIGHTS. THE GALE WATCH HAS THEREFORE BEEN UPGRADED TO A
WARNING. CONSIDERABLE HEAVY FREEZING SPRAY WILL ACCOMPANY THESE
CONDITIONS AND A WARNING HAS BEEN ISSUED ACCORDINGLY. WINDS AND
WAVES WILL SUBSIDE FRIDAY AFTERNOON INTO FRIDAY NIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     FRIDAY FOR LHZ362-363-441-462.

     GALE WARNING FROM 7 PM THIS EVENING TO 10 AM EST FRIDAY FOR LHZ362-
     363-421-441-462.

     HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     FRIDAY FOR LHZ463-464.

     GALE WARNING FROM 10 PM THIS EVENING TO 10 AM EST FRIDAY FOR LHZ442-
     443-463-464.

     HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 4 AM EST
     FRIDAY FOR LHZ361.

     GALE WARNING FROM 7 PM THIS EVENING TO 4 AM EST FRIDAY FOR LHZ361.

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

$$

AVIATION.....SC
UPDATE.......SC
SHORT TERM...DG
LONG TERM....JVC
MARINE.......JVC


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




000
FXUS63 KDTX 291703
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1203 PM EST THU JAN 29 2015


.AVIATION...

THE REGION OF PRECIP NOW MOVING ACROSS SW MI WILL ADVANCE ACROSS THE
TERMINALS EARLY THIS AFTERNOON. THE BULK OF THIS WILL FALL AS SNOW
FROM PTK NORTH AND RAIN/SNOW SOUTH. THERE IS A DEFINITE BACK EDGE TO
THIS PRECIP /MARKED BY THE END OF LARGER SCALE FORCING/. THIS BACK
EDGE WILL MOVE THROUGH SE MI BETWEEN 20Z AND 22Z. THE ASSOCIATED SFC
LOW WILL PASS EAST OF METRO DETROIT AFTER 19Z CAUSING A VEERING OF
THE WIND TOWARD THE W-NW WITH A MODEST INCREASE IN WIND SPEED.
SHALLOW COLD AIR ADVECTION UNDER A DEEP LOW LEVEL INVERSION WILL
SUSTAIN MVFR CIGS THROUGH WELL INTO THE OVERNIGHT. A SECONDARY COLD
FRONT...MARKED BY A PUSH OF ARCTIC AIR WILL ARRIVE LATE THIS EVENING
AND WILL CAUSE A DRAMATIC INCREASE IN THE WINDS /POSSIBLY GUSTING UP
TO 30 KNOTS AT TIMES/.

FOR DTW...ENOUGH WARM AIR IS IN PLACE OVER METRO DETROIT TO SUPPORT
RAIN MIXED WITH SOME SNOW AS THIS SECOND BATCH OF PRECIP ARRIVES
WITHIN THE NEXT HOUR. SFC TEMPS WILL REMAIN ABOVE FREEZING...SO NO
ACCUMULATIONS WITH ANY SNOW IS EXPECTED.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT THIS AFTERNOON AND TONIGHT.

* MEDIUM IN PRECIPITATION BEING MOSTLY RAIN THIS AFTERNOON.

* MEDIUM IN WIND GUSTS EXCEEDING CROSS WIND THRESHOLDS TONIGHT.

&&

.PREV DISCUSSION...ISSUED 948 AM EST THU JAN 29 2015

UPDATE...

THE WATER VAPOR LOOP THIS MORNING SHOWS A SHORT WAVE NOW TRACKING
ACROSS CNTL INDIANA WITH A MID LEVEL TROUGH AXIS EXTENDING FROM
THE WRN UP INTO SRN MN. THE REGIONAL RADAR DATA SHOWS AN AREA OF
SNOW EXTENDING ACROSS NRN AND CNTL LOWER MI...WITHIN THE REGION OF
MID LEVEL DEFORMATION BETWEEN THESE TWO WAVES. THIS DEFORMATION
FORCING WILL BE DRIVEN ACROSS THE NORTHERN HALF OF THE FORECAST
AREA DURING THE LATER HALF OF THE MORNING INTO EARLY
AFTERNOON...LEADING TO SOME REDEVELOPMENT OF SNOW. FARTHER
SOUTH...RADAR DATA HAS BEEN SHOWING SOME RETURNS ACROSS SOUTHERN
LAKE MI. THESE ARE MORE CONVECTIVE IN NATURE IN LIGHT OF THE STEEP
MID LEVEL LAPSE RATES. THESE SHOWERS ARE OCCURRING WITHIN SOME
ADDITIONAL MID LEVEL DEFORMATION ALONG THE NORTHERN EDGE OF THE
OHIO VALLEY WAVE AND WILL AFFECT THE SOUTHERN HALF OF THE FORECAST
AREA LATE THIS MORNING AND AFTERNOON. THE EASTWARD ADVANCEMENT OF
THESE WAVES WILL ALLOW THE FORCING TO REMAIN PROGRESSIVE TODAY.
THERE MAY BE A BRIEF LULL IN PRECIP THIS AFTERNOON PRIOR TO SOME
ENHANCED MID LEVEL FGEN ARRIVING LATER THIS AFTERNOON AHEAD OF THE
NRN STREAM TROUGH AXIS.

THE ASSOC SFC LOW LOCATED ALONG THE IN/MI BORDER AS OF 14Z...WILL
LIFT INTO SE MI BY EARLY AFTERNOON. TEMPS AHEAD OF THIS LOW HAVE
RISEN INTO THE MID/UPPER 30S. THIS WARMER AIR WILL ADVECT INTO
METRO DETROIT. THE DEPTH OF THE WARM AIR LOOKS SUFFICIENT TO KEEP
PRECIP MAINLY LIQUID THROUGH MID AFTERNOON FOR METRO DETROIT
SOUTH /ALTHOUGH THERE MAY BE SOME BRIEF PERIODS OF SLEET IN ANY
HIGHER INTENSITY CONVECTIVE ELEMENTS/. THE WARM LAYER WILL BE MUCH
MORE SHALLOW FARTHER NORTH...SUPPORTING MAINLY SNOW. ADDITIONAL
SNOW ACCUMULATION OF AN INCH OR TWO WILL BE POSSIBLE ACROSS
MIDLAND/BAY/HURON COUNTIES WHERE FORCING WILL BE A LITTLE
STRONGER/MORE PERSISTENT. ACCUMS FARTHER SOUTH SHOULD BE MINIMAL.
COLDER AIR WILL ARRIVE LATE IN THE AFTERNOON WITH THE PASSAGE OF
THE MID LEVEL FGEN...FAVORING A PRECIP CHANGE OVER TO SNOW. THIS
FORCING LOOKS TO BE VERY BRIEF AND WEAK ENOUGH TO KEEP ACCUMS
MINIMAL IF ANY. AN UPDATED FORECAST WILL BE ISSUED SHORTLY TO
REFLECT THESE LATEST PRECIP TRENDS.

PREV DISCUSSION...ISSUED 242 AM EST THU JAN 29 2015

SHORT TERM...TODAY AND TONIGHT

A SHORTWAVE WILL TRACK FROM THE MID MISSISSIPPI VALLEY INTO THE
CENTRAL GREAT LAKES TODAY...SPREADING MOISTURE INTO THE AREA EARLY
THIS MORNING. 00Z KDTX SOUNDING SHOWS A VERY DRY LAYER IN PLACE OVER
LOWER MICHIGAN FROM 750 MB DOWN TO THE SURFACE...WHICH HAS KEPT A
BAND OF MOISTURE WITHIN REGION OF ISENTROPIC ASCENT IN ADVANCE OF
THIS THE MAIN SYSTEM ELEVATED OVERNIGHT.

FORCING ALONG THE LEAD EDGE OF THE VORTICITY CENTER WILL PROGRESS
EAST TO NORTHEAST INTO THE AREA FROM ITS CURRENTLY POSITION FROM
SOUTHWEST LOWER MICHIGAN INTO NORTHERN INDIANA. HOWEVER...BETWEEN
THE DRY LOW LEVELS STILL IN PLACE IN ADVANCE OF THIS BAND OF RAIN
AND SNOW...AND A MID LEVEL DRY SLOT TRAILING THIS FEATURE INTO THE
AREA...PRECIPITATION INTENSITY AND DURATION WILL BE LIMITED EARLY
THIS MORNING OVER MUCH OF THE CWA. ONLY THE NORTHERN THIRD TO HALF
OF THE CWA MAY RECEIVE 3 OR 4 HOURS OF PRECIPITATION...MAINLY SLEET
OR SNOW...ALONG THE NORTHERN EDGE OF THE DRY SLOT.

FURTHER SOUTH INTO METRO DETROIT AND POINTS SOUTH...A BRIEF ONE OR
TWO HOUR PERIOD OF LIGHT SHOWERS OR SLEET WILL CROSS THE AREA. WITH
TEMPERATURES IN THE MID 20S...ANY LIQUID THAT DOES FALL WILL MOST
LIKELY FREEZE ON SURFACES. AT THIS TIME...ONLY PATCHY SLICK SPOTS
ARE EXPECTED GIVEN THE LACK OF COVERAGE OF THE THE PRECIPITATION.
NO HEADLINES ARE ANTICIPATED AT THIS TIME.

AS THE SHORTWAVE CROSSES THE AREA TODAY...ADDITIONAL SNOW SHOWERS
WILL OCCUR AS COLDER AIR ASSOCIATED WITH THE WAVE OVERSPREADS THE
AREA. TEMPERATURES AT THE SURFACE WILL REMAIN AOA FREEZING FOR MUCH
OF THE AREA FROM LATE MORNING INTO THE AFTERNOON AS STRONGER COLD
AIR ADVECTION HOLDS OFF UNTIL THIS EVENING AND TONIGHT. TOTAL SNOW
ACCUMULATIONS OF AN INCH OR TWO WILL BE POSSIBLE DURING THE ENTIRE
PERIOD OVER THE NORTHERN CWA WITH MUCH LESSER AMOUNTS SOUTHWARD FROM
METRO DETROIT TO THE MICHIGAN AND OHIO STATE LINE.

COLD AIR WILL FILTER BACK SOUTH INTO THE AREA TONIGHT WITH THE LOW
TEMPERATURES RANGING FROM THE SINGLE DIGITS TO AROUND 10 DEGREE OVER
THE NORTH TO THE LOW/MID TEENS I-94 SOUTH. ANY REMAINING SNOW
SHOWERS WILL BE INSIGNIFICANT.

LONG TERM...

ARCTIC HIGH PRESSURE BUTTED AGAINST THE FRONT RANGE OF THE ROCKIES
IN ALBERTA THIS MORNING IS INTENSIFYING AS SHORTWAVE RIDGING
DEVELOPS DOWNSTREAM OF THE ALEUTIAN LOW. COLLAPSE OF UPPER SUPPORT
DUE TO INCREASING CONFLUENCE OVER NORTHWEST CANADA WILL FORCE THE
HIGH TO WEAKEN AND QUICKLY TRANSLATE SOUTHEAST INTO THE UPPER
MIDWEST THIS MORNING BEFORE SETTLING OVER THE OHIO VALLEY TONIGHT.
THIS WILL DRIVE A PERSISTENT NW GRADIENT ACROSS THE CWA THROUGH THE
FIRST HALF OF FRIDAY. COLD ADVECTION WILL EASE AS THE BROAD SURFACE
RIDGE AXIS TRAVERSES THE AREA, BUT WITH 925MB TEMPERATURES HOVERING
NEAR -17C, HIGHS WILL BE STUCK IN THE TEENS ON FRIDAY. RAPID
EASTWARD PROGRESS OF THE HIGH AND DRY NW FLOW, SUPPORTED BY
RELATIVELY DRY MOISTURE FIELDS IN THE 00Z NAM, SUGGEST THAT THIS
WILL BE THE CASE EVEN IN THE PRESENCE OF MOSTLY SUNNY SKIES OVER
MOST OF THE AREA. THE POTENTIAL EXCEPTION MAY BE ACROSS THE FAR NW
WHERE LAKE SUPERIOR-MICHIGAN PLUME WILL POTENTIALLY CONTRIBUTE TO A
MORE PERSISTENT STRATOCU DECK. FOR THIS SAME REASON, LOWS SHOULD
EASILY FALL INTO THE SINGLE DIGITS FRIDAY NIGHT, BUT HAVE A HIGHER
LIKELIHOOD OF REMAINING IN THE 10-15 DEGREES ACROSS THE FAR WEST.

A MOISTURE STARVED WAVE EMBEDDED IN NW FLOW WILL RACE ACROSS THE
GREAT LAKES EARLY FRIDAY BRINGING NOTHING MORE THAN A FEW SNOW
SHOWERS ACROSS THE FAR NORTH WITH NO ACCUMULATION EXPECTED.
DEVELOPING RETURN FLOW WILL PUSH HIGHS INTO AT LEAST THE UPPER 20S.

HIGH UNCERTAINTY FOR THE SECOND HALF OF THE WEEKEND. A SHORTWAVE,
WHICH HAS YET TO ACTUALLY DEVELOP, IS FORECAST BY THE SUITE OF
GUIDANCE TO EMERGE OUT OF THE ALEUTIAN LOW LATE TONIGHT AND COME
ONSHORE IN BRITISH COLUMBIA ON FRIDAY EVENING. THIS WAVE WILL
QUICKLY SHEAR TO SOUTHEAST AND INTERACT TO SOME DEGREE WITH A CLOSED
LOW OVER THE BAJA.

WHAT IS KNOWN IS THAT THERE IS A REASONABLE LIKELIHOOD FOR A
PROLONGED PERIOD OF LIGHT TO MODERATE ACCUMULATING SNOW TO DEVELOP
OVER A WIDE AREA GIVEN GIVEN THE BROAD AREA OF ISENTROPIC ASCENT AND
NORTHWARD TRANSPORT OF 4-5 G/KG H7 SPECIFIC HUMIDITY COURTESY OF
SOUTHERN STREAM INVOLVEMENT. THE KEY PLAYER IN THE LOCAL FORECAST
WILL BE JUST HOW AGGRESSIVELY THE NORTHERN BRANCH DIGS OVER MONTANA,
WYOMING, AND COLORADO SATURDAY INTO SATURDAY NIGHT. THE GREATER THE
INTERACTION WITH THE CLOSED LOW, THE GREATER SNOW PROSPECTS BECOME.
AS IT STANDS, THE NAM AND GEM ARE BY FAR THE MOST AGGRESSIVE. THE
ECMWF AND GFS ARE CONSIDERABLY LESS SO AND CONFINE ACCUMULATING SNOW
SOUTH OF THE OHIO BORDER. HOWEVER, THE LATTER TWO STILL MADE
NOTEWORTHY MOVES TOWARD MORE AGGRESSIVE SOLUTIONS AT 00Z IN
COMPARISON TO THEIR 12Z COUNTERPARTS. 00Z GFS ENSEMBLES ARE SPLIT
BETWEEN NORTH/SOUTH SOLUTIONS WITH THE OPERATIONAL GFS AND TWO
CONTROL RUNS REMAINING RIGHT IN BETWEEN AND CENTERING THE ACTION
ALONG/SOUTH OF I-80. GIVEN THAT THE S/W HAS YET TO EMERGE, TYPICAL
NWP PROBLEMS WITH CLOSED LOWS, AND GENERAL LOW MEDIUM RANGE
PREDICTABILITY THIS WINTER, WILL SIMPLY ALLOW THE BLENDED EXTENDED
GRIDS TO SPEAK FOR THEMSELVES AT THIS POINT.

MARINE...

FRESH TO STRONG SOUTHERLY WINDS WILL PERSIST FOR THE NEXT FEW HOURS
AS A WEAK LOW APPROACHES FROM THE WEST. GUSTS WILL BE LIMITED TO
AROUND 30 KNOTS GIVEN THE STABILITY OF WARM SOUTH FLOW. WINDS WILL
VEER TO THE NORTHWEST AND INCREASE CONSIDERABLY THIS EVENING INTO
TONIGHT. WIDESPREAD GALES ARE EXPECTED OVER LAKE HURON WITH GUSTS TO
STRONG GALES EXPECTED OVER CENTRAL AND SOUTHERN LAKE HURON WHERE
SIGNIFICANT WAVE HEIGHTS WILL EXCEED 12 FEET WITH HIGHER MAXIMUM
WAVE HEIGHTS. THE GALE WATCH HAS THEREFORE BEEN UPGRADED TO A
WARNING. CONSIDERABLE HEAVY FREEZING SPRAY WILL ACCOMPANY THESE
CONDITIONS AND A WARNING HAS BEEN ISSUED ACCORDINGLY. WINDS AND
WAVES WILL SUBSIDE FRIDAY AFTERNOON INTO FRIDAY NIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     FRIDAY FOR LHZ362-363-441-462.

     GALE WARNING FROM 7 PM THIS EVENING TO 10 AM EST FRIDAY FOR LHZ362-
     363-421-441-462.

     HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     FRIDAY FOR LHZ463-464.

     GALE WARNING FROM 10 PM THIS EVENING TO 10 AM EST FRIDAY FOR LHZ442-
     443-463-464.

     HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 4 AM EST
     FRIDAY FOR LHZ361.

     GALE WARNING FROM 7 PM THIS EVENING TO 4 AM EST FRIDAY FOR LHZ361.

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

$$

AVIATION.....SC
UPDATE.......SC
SHORT TERM...DG
LONG TERM....JVC
MARINE.......JVC


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





000
FXUS63 KDTX 291448
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
948 AM EST THU JAN 29 2015

.UPDATE...

THE WATER VAPOR LOOP THIS MORNING SHOWS A SHORT WAVE NOW TRACKING
ACROSS CNTL INDIANA WITH A MID LEVEL TROUGH AXIS EXTENDING FROM
THE WRN UP INTO SRN MN. THE REGIONAL RADAR DATA SHOWS AN AREA OF
SNOW EXTENDING ACROSS NRN AND CNTL LOWER MI...WITHIN THE REGION OF
MID LEVEL DEFORMATION BETWEEN THESE TWO WAVES. THIS DEFORMATION
FORCING WILL BE DRIVEN ACROSS THE NORTHERN HALF OF THE FORECAST
AREA DURING THE LATER HALF OF THE MORNING INTO EARLY
AFTERNOON...LEADING TO SOME REDEVELOPMENT OF SNOW. FARTHER
SOUTH...RADAR DATA HAS BEEN SHOWING SOME RETURNS ACROSS SOUTHERN
LAKE MI. THESE ARE MORE CONVECTIVE IN NATURE IN LIGHT OF THE STEEP
MID LEVEL LAPSE RATES. THESE SHOWERS ARE OCCURRING WITHIN SOME
ADDITIONAL MID LEVEL DEFORMATION ALONG THE NORTHERN EDGE OF THE
OHIO VALLEY WAVE AND WILL AFFECT THE SOUTHERN HALF OF THE FORECAST
AREA LATE THIS MORNING AND AFTERNOON. THE EASTWARD ADVANCEMENT OF
THESE WAVES WILL ALLOW THE FORCING TO REMAIN PROGRESSIVE TODAY.
THERE MAY BE A BRIEF LULL IN PRECIP THIS AFTERNOON PRIOR TO SOME
ENHANCED MID LEVEL FGEN ARRIVING LATER THIS AFTERNOON AHEAD OF THE
NRN STREAM TROUGH AXIS.

THE ASSOC SFC LOW LOCATED ALONG THE IN/MI BORDER AS OF 14Z...WILL
LIFT INTO SE MI BY EARLY AFTERNOON. TEMPS AHEAD OF THIS LOW HAVE
RISEN INTO THE MID/UPPER 30S. THIS WARMER AIR WILL ADVECT INTO
METRO DETROIT. THE DEPTH OF THE WARM AIR LOOKS SUFFICIENT TO KEEP
PRECIP MAINLY LIQUID THROUGH MID AFTERNOON FOR METRO DETROIT
SOUTH /ALTHOUGH THERE MAY BE SOME BRIEF PERIODS OF SLEET IN ANY
HIGHER INTENSITY CONVECTIVE ELEMENTS/. THE WARM LAYER WILL BE MUCH
MORE SHALLOW FARTHER NORTH...SUPPORTING MAINLY SNOW. ADDITIONAL
SNOW ACCUMULATION OF AN INCH OR TWO WILL BE POSSIBLE ACROSS
MIDLAND/BAY/HURON COUNTIES WHERE FORCING WILL BE A LITTLE
STRONGER/MORE PERSISTENT. ACCUMS FARTHER SOUTH SHOULD BE MINIMAL.
COLDER AIR WILL ARRIVE LATE IN THE AFTERNOON WITH THE PASSAGE OF
THE MID LEVEL FGEN...FAVORING A PRECIP CHANGE OVER TO SNOW. THIS
FORCING LOOKS TO BE VERY BRIEF AND WEAK ENOUGH TO KEEP ACCUMS
MINIMAL IF ANY. AN UPDATED FORECAST WILL BE ISSUED SHORTLY TO
REFLECT THESE LATEST PRECIP TRENDS.

&&

.AVIATION...ISSUED 603 AM EST THU JAN 29 2015

LEAD FORCING IN ADVANCE OF SHORTWAVE WILL PUSH MOST PRECIPITATION
EAST OF THE TERMINALS AS THE FORECAST BEGINS WITH JUST SCATTERED
-FRZAPL SOUTH OF PTK AND -SNPL NORTH. MID LEVEL DRY SLOT WILL THEN
END PRECIPITATION UNTIL THE ACTUAL VORTICITY CENTER CROSSES THE AREA
IN THE 16Z-23Z TIME FRAME. AT THAT POINT...SCT -SHSN WILL BE COMMON
PTK NORTH WITH SCT -SHRA MIXED WITH AND CHANGING TO -SHSN ALONG THE
I-94 TERMINALS. VFR CIGS WILL BE REPLACED BY MVFR TO OCCASIONAL IFR
CIGS WITH THIS SYSTEM WITH CIGS RISING AGAIN TONIGHT AS DRIER NW
FLOW SETS UP IN ITS WAKE. THESE WINDS WILL BE A BIT GUSTY TONIGHT AS
DOWNWARD MOMENTUM WILL BE ENHANCED WITHIN AREA OF STRONG COLD AIR
ADVECTION.

FOR DTW...A FEW PATCHES OF -FRZAPL WILL END EARLY IN THE FORECAST
AND THEN BE REPLACED BY MIDDAY BY -SHRA...WHICH WILL TURN BACK TO
LIGHT SNOW SHOWERS BY LATE IN THE DAY. BORDERLINE MVFR/IFR CIGS
SHOULD SPREAD INTO THE AREA IN THE 16Z-18Z TIME FRAME WITH THE
LOWEST CIGS OCCURRING 19Z-23Z OR SO.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT AFTER 16Z.

* MEDIUM IN PRECIPITATION TYPE AS -FZRAIP MIX THIS MORNING AND -SHRA
  CHANGING TO -SHSN THIS AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 242 AM EST THU JAN 29 2015

SHORT TERM...TODAY AND TONIGHT

A SHORTWAVE WILL TRACK FROM THE MID MISSISSIPPI VALLEY INTO THE
CENTRAL GREAT LAKES TODAY...SPREADING MOISTURE INTO THE AREA EARLY
THIS MORNING. 00Z KDTX SOUNDING SHOWS A VERY DRY LAYER IN PLACE OVER
LOWER MICHIGAN FROM 750 MB DOWN TO THE SURFACE...WHICH HAS KEPT A
BAND OF MOISTURE WITHIN REGION OF ISENTROPIC ASCENT IN ADVANCE OF
THIS THE MAIN SYSTEM ELEVATED OVERNIGHT.

FORCING ALONG THE LEAD EDGE OF THE VORTICITY CENTER WILL PROGRESS
EAST TO NORTHEAST INTO THE AREA FROM ITS CURRENTLY POSITION FROM
SOUTHWEST LOWER MICHIGAN INTO NORTHERN INDIANA. HOWEVER...BETWEEN
THE DRY LOW LEVELS STILL IN PLACE IN ADVANCE OF THIS BAND OF RAIN
AND SNOW...AND A MID LEVEL DRY SLOT TRAILING THIS FEATURE INTO THE
AREA...PRECIPITATION INTENSITY AND DURATION WILL BE LIMITED EARLY
THIS MORNING OVER MUCH OF THE CWA. ONLY THE NORTHERN THIRD TO HALF
OF THE CWA MAY RECEIVE 3 OR 4 HOURS OF PRECIPITATION...MAINLY SLEET
OR SNOW...ALONG THE NORTHERN EDGE OF THE DRY SLOT.

FURTHER SOUTH INTO METRO DETROIT AND POINTS SOUTH...A BRIEF ONE OR
TWO HOUR PERIOD OF LIGHT SHOWERS OR SLEET WILL CROSS THE AREA. WITH
TEMPERATURES IN THE MID 20S...ANY LIQUID THAT DOES FALL WILL MOST
LIKELY FREEZE ON SURFACES. AT THIS TIME...ONLY PATCHY SLICK SPOTS
ARE EXPECTED GIVEN THE LACK OF COVERAGE OF THE THE PRECIPITATION.
NO HEADLINES ARE ANTICIPATED AT THIS TIME.

AS THE SHORTWAVE CROSSES THE AREA TODAY...ADDITIONAL SNOW SHOWERS
WILL OCCUR AS COLDER AIR ASSOCIATED WITH THE WAVE OVERSPREADS THE
AREA. TEMPERATURES AT THE SURFACE WILL REMAIN AOA FREEZING FOR MUCH
OF THE AREA FROM LATE MORNING INTO THE AFTERNOON AS STRONGER COLD
AIR ADVECTION HOLDS OFF UNTIL THIS EVENING AND TONIGHT. TOTAL SNOW
ACCUMULATIONS OF AN INCH OR TWO WILL BE POSSIBLE DURING THE ENTIRE
PERIOD OVER THE NORTHERN CWA WITH MUCH LESSER AMOUNTS SOUTHWARD FROM
METRO DETROIT TO THE MICHIGAN AND OHIO STATE LINE.

COLD AIR WILL FILTER BACK SOUTH INTO THE AREA TONIGHT WITH THE LOW
TEMPERATURES RANGING FROM THE SINGLE DIGITS TO AROUND 10 DEGREE OVER
THE NORTH TO THE LOW/MID TEENS I-94 SOUTH. ANY REMAINING SNOW
SHOWERS WILL BE INSIGNIFICANT.

LONG TERM...

ARCTIC HIGH PRESSURE BUTTED AGAINST THE FRONT RANGE OF THE ROCKIES
IN ALBERTA THIS MORNING IS INTENSIFYING AS SHORTWAVE RIDGING
DEVELOPS DOWNSTREAM OF THE ALEUTIAN LOW. COLLAPSE OF UPPER SUPPORT
DUE TO INCREASING CONFLUENCE OVER NORTHWEST CANADA WILL FORCE THE
HIGH TO WEAKEN AND QUICKLY TRANSLATE SOUTHEAST INTO THE UPPER
MIDWEST THIS MORNING BEFORE SETTLING OVER THE OHIO VALLEY TONIGHT.
THIS WILL DRIVE A PERSISTENT NW GRADIENT ACROSS THE CWA THROUGH THE
FIRST HALF OF FRIDAY. COLD ADVECTION WILL EASE AS THE BROAD SURFACE
RIDGE AXIS TRAVERSES THE AREA, BUT WITH 925MB TEMPERATURES HOVERING
NEAR -17C, HIGHS WILL BE STUCK IN THE TEENS ON FRIDAY. RAPID
EASTWARD PROGRESS OF THE HIGH AND DRY NW FLOW, SUPPORTED BY
RELATIVELY DRY MOISTURE FIELDS IN THE 00Z NAM, SUGGEST THAT THIS
WILL BE THE CASE EVEN IN THE PRESENCE OF MOSTLY SUNNY SKIES OVER
MOST OF THE AREA. THE POTENTIAL EXCEPTION MAY BE ACROSS THE FAR NW
WHERE LAKE SUPERIOR-MICHIGAN PLUME WILL POTENTIALLY CONTRIBUTE TO A
MORE PERSISTENT STRATOCU DECK. FOR THIS SAME REASON, LOWS SHOULD
EASILY FALL INTO THE SINGLE DIGITS FRIDAY NIGHT, BUT HAVE A HIGHER
LIKELIHOOD OF REMAINING IN THE 10-15 DEGREES ACROSS THE FAR WEST.

A MOISTURE STARVED WAVE EMBEDDED IN NW FLOW WILL RACE ACROSS THE
GREAT LAKES EARLY FRIDAY BRINGING NOTHING MORE THAN A FEW SNOW
SHOWERS ACROSS THE FAR NORTH WITH NO ACCUMULATION EXPECTED.
DEVELOPING RETURN FLOW WILL PUSH HIGHS INTO AT LEAST THE UPPER 20S.

HIGH UNCERTAINTY FOR THE SECOND HALF OF THE WEEKEND. A SHORTWAVE,
WHICH HAS YET TO ACTUALLY DEVELOP, IS FORECAST BY THE SUITE OF
GUIDANCE TO EMERGE OUT OF THE ALEUTIAN LOW LATE TONIGHT AND COME
ONSHORE IN BRITISH COLUMBIA ON FRIDAY EVENING. THIS WAVE WILL
QUICKLY SHEAR TO SOUTHEAST AND INTERACT TO SOME DEGREE WITH A CLOSED
LOW OVER THE BAJA.

WHAT IS KNOWN IS THAT THERE IS A REASONABLE LIKELIHOOD FOR A
PROLONGED PERIOD OF LIGHT TO MODERATE ACCUMULATING SNOW TO DEVELOP
OVER A WIDE AREA GIVEN GIVEN THE BROAD AREA OF ISENTROPIC ASCENT AND
NORTHWARD TRANSPORT OF 4-5 G/KG H7 SPECIFIC HUMIDITY COURTESY OF
SOUTHERN STREAM INVOLVEMENT. THE KEY PLAYER IN THE LOCAL FORECAST
WILL BE JUST HOW AGGRESSIVELY THE NORTHERN BRANCH DIGS OVER MONTANA,
WYOMING, AND COLORADO SATURDAY INTO SATURDAY NIGHT. THE GREATER THE
INTERACTION WITH THE CLOSED LOW, THE GREATER SNOW PROSPECTS BECOME.
AS IT STANDS, THE NAM AND GEM ARE BY FAR THE MOST AGGRESSIVE. THE
ECMWF AND GFS ARE CONSIDERABLY LESS SO AND CONFINE ACCUMULATING SNOW
SOUTH OF THE OHIO BORDER. HOWEVER, THE LATTER TWO STILL MADE
NOTEWORTHY MOVES TOWARD MORE AGGRESSIVE SOLUTIONS AT 00Z IN
COMPARISON TO THEIR 12Z COUNTERPARTS. 00Z GFS ENSEMBLES ARE SPLIT
BETWEEN NORTH/SOUTH SOLUTIONS WITH THE OPERATIONAL GFS AND TWO
CONTROL RUNS REMAINING RIGHT IN BETWEEN AND CENTERING THE ACTION
ALONG/SOUTH OF I-80. GIVEN THAT THE S/W HAS YET TO EMERGE, TYPICAL
NWP PROBLEMS WITH CLOSED LOWS, AND GENERAL LOW MEDIUM RANGE
PREDICTABILITY THIS WINTER, WILL SIMPLY ALLOW THE BLENDED EXTENDED
GRIDS TO SPEAK FOR THEMSELVES AT THIS POINT.

MARINE...

FRESH TO STRONG SOUTHERLY WINDS WILL PERSIST FOR THE NEXT FEW HOURS
AS A WEAK LOW APPROACHES FROM THE WEST. GUSTS WILL BE LIMITED TO
AROUND 30 KNOTS GIVEN THE STABILITY OF WARM SOUTH FLOW. WINDS WILL
VEER TO THE NORTHWEST AND INCREASE CONSIDERABLY THIS EVENING INTO
TONIGHT. WIDESPREAD GALES ARE EXPECTED OVER LAKE HURON WITH GUSTS TO
STRONG GALES EXPECTED OVER CENTRAL AND SOUTHERN LAKE HURON WHERE
SIGNIFICANT WAVE HEIGHTS WILL EXCEED 12 FEET WITH HIGHER MAXIMUM
WAVE HEIGHTS. THE GALE WATCH HAS THEREFORE BEEN UPGRADED TO A
WARNING. CONSIDERABLE HEAVY FREEZING SPRAY WILL ACCOMPANY THESE
CONDITIONS AND A WARNING HAS BEEN ISSUED ACCORDINGLY. WINDS AND
WAVES WILL SUBSIDE FRIDAY AFTERNOON INTO FRIDAY NIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 10 AM EST
     FRIDAY FOR LHZ362-363-421-441-462.

     GALE WARNING FROM 7 PM THIS EVENING TO 10 AM EST FRIDAY FOR LHZ362-
     363-421-441-462.

     HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 10 AM EST
     FRIDAY FOR LHZ442-443-463-464.

     GALE WARNING FROM 10 PM THIS EVENING TO 10 AM EST FRIDAY FOR LHZ442-
     443-463-464.

     HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 4 AM EST
     FRIDAY FOR LHZ361.

     GALE WARNING FROM 7 PM THIS EVENING TO 4 AM EST FRIDAY FOR LHZ361.

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

$$

UPDATE.......SC
AVIATION.....DG
SHORT TERM...DG
LONG TERM....JVC
MARINE.......JVC


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





000
FXUS63 KDTX 291448
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
948 AM EST THU JAN 29 2015

.UPDATE...

THE WATER VAPOR LOOP THIS MORNING SHOWS A SHORT WAVE NOW TRACKING
ACROSS CNTL INDIANA WITH A MID LEVEL TROUGH AXIS EXTENDING FROM
THE WRN UP INTO SRN MN. THE REGIONAL RADAR DATA SHOWS AN AREA OF
SNOW EXTENDING ACROSS NRN AND CNTL LOWER MI...WITHIN THE REGION OF
MID LEVEL DEFORMATION BETWEEN THESE TWO WAVES. THIS DEFORMATION
FORCING WILL BE DRIVEN ACROSS THE NORTHERN HALF OF THE FORECAST
AREA DURING THE LATER HALF OF THE MORNING INTO EARLY
AFTERNOON...LEADING TO SOME REDEVELOPMENT OF SNOW. FARTHER
SOUTH...RADAR DATA HAS BEEN SHOWING SOME RETURNS ACROSS SOUTHERN
LAKE MI. THESE ARE MORE CONVECTIVE IN NATURE IN LIGHT OF THE STEEP
MID LEVEL LAPSE RATES. THESE SHOWERS ARE OCCURRING WITHIN SOME
ADDITIONAL MID LEVEL DEFORMATION ALONG THE NORTHERN EDGE OF THE
OHIO VALLEY WAVE AND WILL AFFECT THE SOUTHERN HALF OF THE FORECAST
AREA LATE THIS MORNING AND AFTERNOON. THE EASTWARD ADVANCEMENT OF
THESE WAVES WILL ALLOW THE FORCING TO REMAIN PROGRESSIVE TODAY.
THERE MAY BE A BRIEF LULL IN PRECIP THIS AFTERNOON PRIOR TO SOME
ENHANCED MID LEVEL FGEN ARRIVING LATER THIS AFTERNOON AHEAD OF THE
NRN STREAM TROUGH AXIS.

THE ASSOC SFC LOW LOCATED ALONG THE IN/MI BORDER AS OF 14Z...WILL
LIFT INTO SE MI BY EARLY AFTERNOON. TEMPS AHEAD OF THIS LOW HAVE
RISEN INTO THE MID/UPPER 30S. THIS WARMER AIR WILL ADVECT INTO
METRO DETROIT. THE DEPTH OF THE WARM AIR LOOKS SUFFICIENT TO KEEP
PRECIP MAINLY LIQUID THROUGH MID AFTERNOON FOR METRO DETROIT
SOUTH /ALTHOUGH THERE MAY BE SOME BRIEF PERIODS OF SLEET IN ANY
HIGHER INTENSITY CONVECTIVE ELEMENTS/. THE WARM LAYER WILL BE MUCH
MORE SHALLOW FARTHER NORTH...SUPPORTING MAINLY SNOW. ADDITIONAL
SNOW ACCUMULATION OF AN INCH OR TWO WILL BE POSSIBLE ACROSS
MIDLAND/BAY/HURON COUNTIES WHERE FORCING WILL BE A LITTLE
STRONGER/MORE PERSISTENT. ACCUMS FARTHER SOUTH SHOULD BE MINIMAL.
COLDER AIR WILL ARRIVE LATE IN THE AFTERNOON WITH THE PASSAGE OF
THE MID LEVEL FGEN...FAVORING A PRECIP CHANGE OVER TO SNOW. THIS
FORCING LOOKS TO BE VERY BRIEF AND WEAK ENOUGH TO KEEP ACCUMS
MINIMAL IF ANY. AN UPDATED FORECAST WILL BE ISSUED SHORTLY TO
REFLECT THESE LATEST PRECIP TRENDS.

&&

.AVIATION...ISSUED 603 AM EST THU JAN 29 2015

LEAD FORCING IN ADVANCE OF SHORTWAVE WILL PUSH MOST PRECIPITATION
EAST OF THE TERMINALS AS THE FORECAST BEGINS WITH JUST SCATTERED
-FRZAPL SOUTH OF PTK AND -SNPL NORTH. MID LEVEL DRY SLOT WILL THEN
END PRECIPITATION UNTIL THE ACTUAL VORTICITY CENTER CROSSES THE AREA
IN THE 16Z-23Z TIME FRAME. AT THAT POINT...SCT -SHSN WILL BE COMMON
PTK NORTH WITH SCT -SHRA MIXED WITH AND CHANGING TO -SHSN ALONG THE
I-94 TERMINALS. VFR CIGS WILL BE REPLACED BY MVFR TO OCCASIONAL IFR
CIGS WITH THIS SYSTEM WITH CIGS RISING AGAIN TONIGHT AS DRIER NW
FLOW SETS UP IN ITS WAKE. THESE WINDS WILL BE A BIT GUSTY TONIGHT AS
DOWNWARD MOMENTUM WILL BE ENHANCED WITHIN AREA OF STRONG COLD AIR
ADVECTION.

FOR DTW...A FEW PATCHES OF -FRZAPL WILL END EARLY IN THE FORECAST
AND THEN BE REPLACED BY MIDDAY BY -SHRA...WHICH WILL TURN BACK TO
LIGHT SNOW SHOWERS BY LATE IN THE DAY. BORDERLINE MVFR/IFR CIGS
SHOULD SPREAD INTO THE AREA IN THE 16Z-18Z TIME FRAME WITH THE
LOWEST CIGS OCCURRING 19Z-23Z OR SO.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT AFTER 16Z.

* MEDIUM IN PRECIPITATION TYPE AS -FZRAIP MIX THIS MORNING AND -SHRA
  CHANGING TO -SHSN THIS AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 242 AM EST THU JAN 29 2015

SHORT TERM...TODAY AND TONIGHT

A SHORTWAVE WILL TRACK FROM THE MID MISSISSIPPI VALLEY INTO THE
CENTRAL GREAT LAKES TODAY...SPREADING MOISTURE INTO THE AREA EARLY
THIS MORNING. 00Z KDTX SOUNDING SHOWS A VERY DRY LAYER IN PLACE OVER
LOWER MICHIGAN FROM 750 MB DOWN TO THE SURFACE...WHICH HAS KEPT A
BAND OF MOISTURE WITHIN REGION OF ISENTROPIC ASCENT IN ADVANCE OF
THIS THE MAIN SYSTEM ELEVATED OVERNIGHT.

FORCING ALONG THE LEAD EDGE OF THE VORTICITY CENTER WILL PROGRESS
EAST TO NORTHEAST INTO THE AREA FROM ITS CURRENTLY POSITION FROM
SOUTHWEST LOWER MICHIGAN INTO NORTHERN INDIANA. HOWEVER...BETWEEN
THE DRY LOW LEVELS STILL IN PLACE IN ADVANCE OF THIS BAND OF RAIN
AND SNOW...AND A MID LEVEL DRY SLOT TRAILING THIS FEATURE INTO THE
AREA...PRECIPITATION INTENSITY AND DURATION WILL BE LIMITED EARLY
THIS MORNING OVER MUCH OF THE CWA. ONLY THE NORTHERN THIRD TO HALF
OF THE CWA MAY RECEIVE 3 OR 4 HOURS OF PRECIPITATION...MAINLY SLEET
OR SNOW...ALONG THE NORTHERN EDGE OF THE DRY SLOT.

FURTHER SOUTH INTO METRO DETROIT AND POINTS SOUTH...A BRIEF ONE OR
TWO HOUR PERIOD OF LIGHT SHOWERS OR SLEET WILL CROSS THE AREA. WITH
TEMPERATURES IN THE MID 20S...ANY LIQUID THAT DOES FALL WILL MOST
LIKELY FREEZE ON SURFACES. AT THIS TIME...ONLY PATCHY SLICK SPOTS
ARE EXPECTED GIVEN THE LACK OF COVERAGE OF THE THE PRECIPITATION.
NO HEADLINES ARE ANTICIPATED AT THIS TIME.

AS THE SHORTWAVE CROSSES THE AREA TODAY...ADDITIONAL SNOW SHOWERS
WILL OCCUR AS COLDER AIR ASSOCIATED WITH THE WAVE OVERSPREADS THE
AREA. TEMPERATURES AT THE SURFACE WILL REMAIN AOA FREEZING FOR MUCH
OF THE AREA FROM LATE MORNING INTO THE AFTERNOON AS STRONGER COLD
AIR ADVECTION HOLDS OFF UNTIL THIS EVENING AND TONIGHT. TOTAL SNOW
ACCUMULATIONS OF AN INCH OR TWO WILL BE POSSIBLE DURING THE ENTIRE
PERIOD OVER THE NORTHERN CWA WITH MUCH LESSER AMOUNTS SOUTHWARD FROM
METRO DETROIT TO THE MICHIGAN AND OHIO STATE LINE.

COLD AIR WILL FILTER BACK SOUTH INTO THE AREA TONIGHT WITH THE LOW
TEMPERATURES RANGING FROM THE SINGLE DIGITS TO AROUND 10 DEGREE OVER
THE NORTH TO THE LOW/MID TEENS I-94 SOUTH. ANY REMAINING SNOW
SHOWERS WILL BE INSIGNIFICANT.

LONG TERM...

ARCTIC HIGH PRESSURE BUTTED AGAINST THE FRONT RANGE OF THE ROCKIES
IN ALBERTA THIS MORNING IS INTENSIFYING AS SHORTWAVE RIDGING
DEVELOPS DOWNSTREAM OF THE ALEUTIAN LOW. COLLAPSE OF UPPER SUPPORT
DUE TO INCREASING CONFLUENCE OVER NORTHWEST CANADA WILL FORCE THE
HIGH TO WEAKEN AND QUICKLY TRANSLATE SOUTHEAST INTO THE UPPER
MIDWEST THIS MORNING BEFORE SETTLING OVER THE OHIO VALLEY TONIGHT.
THIS WILL DRIVE A PERSISTENT NW GRADIENT ACROSS THE CWA THROUGH THE
FIRST HALF OF FRIDAY. COLD ADVECTION WILL EASE AS THE BROAD SURFACE
RIDGE AXIS TRAVERSES THE AREA, BUT WITH 925MB TEMPERATURES HOVERING
NEAR -17C, HIGHS WILL BE STUCK IN THE TEENS ON FRIDAY. RAPID
EASTWARD PROGRESS OF THE HIGH AND DRY NW FLOW, SUPPORTED BY
RELATIVELY DRY MOISTURE FIELDS IN THE 00Z NAM, SUGGEST THAT THIS
WILL BE THE CASE EVEN IN THE PRESENCE OF MOSTLY SUNNY SKIES OVER
MOST OF THE AREA. THE POTENTIAL EXCEPTION MAY BE ACROSS THE FAR NW
WHERE LAKE SUPERIOR-MICHIGAN PLUME WILL POTENTIALLY CONTRIBUTE TO A
MORE PERSISTENT STRATOCU DECK. FOR THIS SAME REASON, LOWS SHOULD
EASILY FALL INTO THE SINGLE DIGITS FRIDAY NIGHT, BUT HAVE A HIGHER
LIKELIHOOD OF REMAINING IN THE 10-15 DEGREES ACROSS THE FAR WEST.

A MOISTURE STARVED WAVE EMBEDDED IN NW FLOW WILL RACE ACROSS THE
GREAT LAKES EARLY FRIDAY BRINGING NOTHING MORE THAN A FEW SNOW
SHOWERS ACROSS THE FAR NORTH WITH NO ACCUMULATION EXPECTED.
DEVELOPING RETURN FLOW WILL PUSH HIGHS INTO AT LEAST THE UPPER 20S.

HIGH UNCERTAINTY FOR THE SECOND HALF OF THE WEEKEND. A SHORTWAVE,
WHICH HAS YET TO ACTUALLY DEVELOP, IS FORECAST BY THE SUITE OF
GUIDANCE TO EMERGE OUT OF THE ALEUTIAN LOW LATE TONIGHT AND COME
ONSHORE IN BRITISH COLUMBIA ON FRIDAY EVENING. THIS WAVE WILL
QUICKLY SHEAR TO SOUTHEAST AND INTERACT TO SOME DEGREE WITH A CLOSED
LOW OVER THE BAJA.

WHAT IS KNOWN IS THAT THERE IS A REASONABLE LIKELIHOOD FOR A
PROLONGED PERIOD OF LIGHT TO MODERATE ACCUMULATING SNOW TO DEVELOP
OVER A WIDE AREA GIVEN GIVEN THE BROAD AREA OF ISENTROPIC ASCENT AND
NORTHWARD TRANSPORT OF 4-5 G/KG H7 SPECIFIC HUMIDITY COURTESY OF
SOUTHERN STREAM INVOLVEMENT. THE KEY PLAYER IN THE LOCAL FORECAST
WILL BE JUST HOW AGGRESSIVELY THE NORTHERN BRANCH DIGS OVER MONTANA,
WYOMING, AND COLORADO SATURDAY INTO SATURDAY NIGHT. THE GREATER THE
INTERACTION WITH THE CLOSED LOW, THE GREATER SNOW PROSPECTS BECOME.
AS IT STANDS, THE NAM AND GEM ARE BY FAR THE MOST AGGRESSIVE. THE
ECMWF AND GFS ARE CONSIDERABLY LESS SO AND CONFINE ACCUMULATING SNOW
SOUTH OF THE OHIO BORDER. HOWEVER, THE LATTER TWO STILL MADE
NOTEWORTHY MOVES TOWARD MORE AGGRESSIVE SOLUTIONS AT 00Z IN
COMPARISON TO THEIR 12Z COUNTERPARTS. 00Z GFS ENSEMBLES ARE SPLIT
BETWEEN NORTH/SOUTH SOLUTIONS WITH THE OPERATIONAL GFS AND TWO
CONTROL RUNS REMAINING RIGHT IN BETWEEN AND CENTERING THE ACTION
ALONG/SOUTH OF I-80. GIVEN THAT THE S/W HAS YET TO EMERGE, TYPICAL
NWP PROBLEMS WITH CLOSED LOWS, AND GENERAL LOW MEDIUM RANGE
PREDICTABILITY THIS WINTER, WILL SIMPLY ALLOW THE BLENDED EXTENDED
GRIDS TO SPEAK FOR THEMSELVES AT THIS POINT.

MARINE...

FRESH TO STRONG SOUTHERLY WINDS WILL PERSIST FOR THE NEXT FEW HOURS
AS A WEAK LOW APPROACHES FROM THE WEST. GUSTS WILL BE LIMITED TO
AROUND 30 KNOTS GIVEN THE STABILITY OF WARM SOUTH FLOW. WINDS WILL
VEER TO THE NORTHWEST AND INCREASE CONSIDERABLY THIS EVENING INTO
TONIGHT. WIDESPREAD GALES ARE EXPECTED OVER LAKE HURON WITH GUSTS TO
STRONG GALES EXPECTED OVER CENTRAL AND SOUTHERN LAKE HURON WHERE
SIGNIFICANT WAVE HEIGHTS WILL EXCEED 12 FEET WITH HIGHER MAXIMUM
WAVE HEIGHTS. THE GALE WATCH HAS THEREFORE BEEN UPGRADED TO A
WARNING. CONSIDERABLE HEAVY FREEZING SPRAY WILL ACCOMPANY THESE
CONDITIONS AND A WARNING HAS BEEN ISSUED ACCORDINGLY. WINDS AND
WAVES WILL SUBSIDE FRIDAY AFTERNOON INTO FRIDAY NIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 10 AM EST
     FRIDAY FOR LHZ362-363-421-441-462.

     GALE WARNING FROM 7 PM THIS EVENING TO 10 AM EST FRIDAY FOR LHZ362-
     363-421-441-462.

     HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 10 AM EST
     FRIDAY FOR LHZ442-443-463-464.

     GALE WARNING FROM 10 PM THIS EVENING TO 10 AM EST FRIDAY FOR LHZ442-
     443-463-464.

     HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 4 AM EST
     FRIDAY FOR LHZ361.

     GALE WARNING FROM 7 PM THIS EVENING TO 4 AM EST FRIDAY FOR LHZ361.

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

$$

UPDATE.......SC
AVIATION.....DG
SHORT TERM...DG
LONG TERM....JVC
MARINE.......JVC


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




000
FXUS63 KDTX 291103
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
603 AM EST THU JAN 29 2015


.AVIATION...

LEAD FORCING IN ADVANCE OF SHORTWAVE WILL PUSH MOST PRECIPITATION
EAST OF THE TERMINALS AS THE FORECAST BEGINS WITH JUST SCATTERED
-FRZAPL SOUTH OF PTK AND -SNPL NORTH. MID LEVEL DRY SLOT WILL THEN
END PRECIPITATION UNTIL THE ACTUAL VORTICITY CENTER CROSSES THE AREA
IN THE 16Z-23Z TIME FRAME. AT THAT POINT...SCT -SHSN WILL BE COMMON
PTK NORTH WITH SCT -SHRA MIXED WITH AND CHANGING TO -SHSN ALONG THE
I-94 TERMINALS. VFR CIGS WILL BE REPLACED BY MVFR TO OCCASIONAL IFR
CIGS WITH THIS SYSTEM WITH CIGS RISING AGAIN TONIGHT AS DRIER NW
FLOW SETS UP IN ITS WAKE. THESE WINDS WILL BE A BIT GUSTY TONIGHT AS
DOWNWARD MOMENTUM WILL BE ENHANCED WITHIN AREA OF STRONG COLD AIR
ADVECTION.

FOR DTW...A FEW PATCHES OF -FRZAPL WILL END EARLY IN THE FORECAST
AND THEN BE REPLACED BY MIDDAY BY -SHRA...WHICH WILL TURN BACK TO
LIGHT SNOW SHOWERS BY LATE IN THE DAY. BORDERLINE MVFR/IFR CIGS
SHOULD SPREAD INTO THE AREA IN THE 16Z-18Z TIME FRAME WITH THE
LOWEST CIGS OCCURRING 19Z-23Z OR SO.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT AFTER 16Z.

* MEDIUM IN PRECIPITATION TYPE AS -FZRAIP MIX THIS MORNING AND -SHRA
  CHANGING TO -SHSN THIS AFTERNOON.

&&

.PREV DISCUSSION...ISSUED 242 AM EST THU JAN 29 2015

SHORT TERM...TODAY AND TONIGHT

A SHORTWAVE WILL TRACK FROM THE MID MISSISSIPPI VALLEY INTO THE
CENTRAL GREAT LAKES TODAY...SPREADING MOISTURE INTO THE AREA EARLY
THIS MORNING. 00Z KDTX SOUNDING SHOWS A VERY DRY LAYER IN PLACE OVER
LOWER MICHIGAN FROM 750 MB DOWN TO THE SURFACE...WHICH HAS KEPT A
BAND OF MOISTURE WITHIN REGION OF ISENTROPIC ASCENT IN ADVANCE OF
THIS THE MAIN SYSTEM ELEVATED OVERNIGHT.

FORCING ALONG THE LEAD EDGE OF THE VORTICITY CENTER WILL PROGRESS
EAST TO NORTHEAST INTO THE AREA FROM ITS CURRENTLY POSITION FROM
SOUTHWEST LOWER MICHIGAN INTO NORTHERN INDIANA. HOWEVER...BETWEEN
THE DRY LOW LEVELS STILL IN PLACE IN ADVANCE OF THIS BAND OF RAIN
AND SNOW...AND A MID LEVEL DRY SLOT TRAILING THIS FEATURE INTO THE
AREA...PRECIPITATION INTENSITY AND DURATION WILL BE LIMITED EARLY
THIS MORNING OVER MUCH OF THE CWA. ONLY THE NORTHERN THIRD TO HALF
OF THE CWA MAY RECEIVE 3 OR 4 HOURS OF PRECIPITATION...MAINLY SLEET
OR SNOW...ALONG THE NORTHERN EDGE OF THE DRY SLOT.

FURTHER SOUTH INTO METRO DETROIT AND POINTS SOUTH...A BRIEF ONE OR
TWO HOUR PERIOD OF LIGHT SHOWERS OR SLEET WILL CROSS THE AREA. WITH
TEMPERATURES IN THE MID 20S...ANY LIQUID THAT DOES FALL WILL MOST
LIKELY FREEZE ON SURFACES. AT THIS TIME...ONLY PATCHY SLICK SPOTS
ARE EXPECTED GIVEN THE LACK OF COVERAGE OF THE THE PRECIPITATION.
NO HEADLINES ARE ANTICIPATED AT THIS TIME.

AS THE SHORTWAVE CROSSES THE AREA TODAY...ADDITIONAL SNOW SHOWERS
WILL OCCUR AS COLDER AIR ASSOCIATED WITH THE WAVE OVERSPREADS THE
AREA. TEMPERATURES AT THE SURFACE WILL REMAIN AOA FREEZING FOR MUCH
OF THE AREA FROM LATE MORNING INTO THE AFTERNOON AS STRONGER COLD
AIR ADVECTION HOLDS OFF UNTIL THIS EVENING AND TONIGHT. TOTAL SNOW
ACCUMULATIONS OF AN INCH OR TWO WILL BE POSSIBLE DURING THE ENTIRE
PERIOD OVER THE NORTHERN CWA WITH MUCH LESSER AMOUNTS SOUTHWARD FROM
METRO DETROIT TO THE MICHIGAN AND OHIO STATE LINE.

COLD AIR WILL FILTER BACK SOUTH INTO THE AREA TONIGHT WITH THE LOW
TEMPERATURES RANGING FROM THE SINGLE DIGITS TO AROUND 10 DEGREE OVER
THE NORTH TO THE LOW/MID TEENS I-94 SOUTH. ANY REMAINING SNOW
SHOWERS WILL BE INSIGNIFICANT.

LONG TERM...

ARCTIC HIGH PRESSURE BUTTED AGAINST THE FRONT RANGE OF THE ROCKIES
IN ALBERTA THIS MORNING IS INTENSIFYING AS SHORTWAVE RIDGING
DEVELOPS DOWNSTREAM OF THE ALEUTIAN LOW. COLLAPSE OF UPPER SUPPORT
DUE TO INCREASING CONFLUENCE OVER NORTHWEST CANADA WILL FORCE THE
HIGH TO WEAKEN AND QUICKLY TRANSLATE SOUTHEAST INTO THE UPPER
MIDWEST THIS MORNING BEFORE SETTLING OVER THE OHIO VALLEY TONIGHT.
THIS WILL DRIVE A PERSISTENT NW GRADIENT ACROSS THE CWA THROUGH THE
FIRST HALF OF FRIDAY. COLD ADVECTION WILL EASE AS THE BROAD SURFACE
RIDGE AXIS TRAVERSES THE AREA, BUT WITH 925MB TEMPERATURES HOVERING
NEAR -17C, HIGHS WILL BE STUCK IN THE TEENS ON FRIDAY. RAPID
EASTWARD PROGRESS OF THE HIGH AND DRY NW FLOW, SUPPORTED BY
RELATIVELY DRY MOISTURE FIELDS IN THE 00Z NAM, SUGGEST THAT THIS
WILL BE THE CASE EVEN IN THE PRESENCE OF MOSTLY SUNNY SKIES OVER
MOST OF THE AREA. THE POTENTIAL EXCEPTION MAY BE ACROSS THE FAR NW
WHERE LAKE SUPERIOR-MICHIGAN PLUME WILL POTENTIALLY CONTRIBUTE TO A
MORE PERSISTENT STRATOCU DECK. FOR THIS SAME REASON, LOWS SHOULD
EASILY FALL INTO THE SINGLE DIGITS FRIDAY NIGHT, BUT HAVE A HIGHER
LIKELIHOOD OF REMAINING IN THE 10-15 DEGREES ACROSS THE FAR WEST.

A MOISTURE STARVED WAVE EMBEDDED IN NW FLOW WILL RACE ACROSS THE
GREAT LAKES EARLY FRIDAY BRINGING NOTHING MORE THAN A FEW SNOW
SHOWERS ACROSS THE FAR NORTH WITH NO ACCUMULATION EXPECTED.
DEVELOPING RETURN FLOW WILL PUSH HIGHS INTO AT LEAST THE UPPER 20S.

HIGH UNCERTAINTY FOR THE SECOND HALF OF THE WEEKEND. A SHORTWAVE,
WHICH HAS YET TO ACTUALLY DEVELOP, IS FORECAST BY THE SUITE OF
GUIDANCE TO EMERGE OUT OF THE ALEUTIAN LOW LATE TONIGHT AND COME
ONSHORE IN BRITISH COLUMBIA ON FRIDAY EVENING. THIS WAVE WILL
QUICKLY SHEAR TO SOUTHEAST AND INTERACT TO SOME DEGREE WITH A CLOSED
LOW OVER THE BAJA.

WHAT IS KNOWN IS THAT THERE IS A REASONABLE LIKELIHOOD FOR A
PROLONGED PERIOD OF LIGHT TO MODERATE ACCUMULATING SNOW TO DEVELOP
OVER A WIDE AREA GIVEN GIVEN THE BROAD AREA OF ISENTROPIC ASCENT AND
NORTHWARD TRANSPORT OF 4-5 G/KG H7 SPECIFIC HUMIDITY COURTESY OF
SOUTHERN STREAM INVOLVEMENT. THE KEY PLAYER IN THE LOCAL FORECAST
WILL BE JUST HOW AGGRESSIVELY THE NORTHERN BRANCH DIGS OVER MONTANA,
WYOMING, AND COLORADO SATURDAY INTO SATURDAY NIGHT. THE GREATER THE
INTERACTION WITH THE CLOSED LOW, THE GREATER SNOW PROSPECTS BECOME.
AS IT STANDS, THE NAM AND GEM ARE BY FAR THE MOST AGGRESSIVE. THE
ECMWF AND GFS ARE CONSIDERABLY LESS SO AND CONFINE ACCUMULATING SNOW
SOUTH OF THE OHIO BORDER. HOWEVER, THE LATTER TWO STILL MADE
NOTEWORTHY MOVES TOWARD MORE AGGRESSIVE SOLUTIONS AT 00Z IN
COMPARISON TO THEIR 12Z COUNTERPARTS. 00Z GFS ENSEMBLES ARE SPLIT
BETWEEN NORTH/SOUTH SOLUTIONS WITH THE OPERATIONAL GFS AND TWO
CONTROL RUNS REMAINING RIGHT IN BETWEEN AND CENTERING THE ACTION
ALONG/SOUTH OF I-80. GIVEN THAT THE S/W HAS YET TO EMERGE, TYPICAL
NWP PROBLEMS WITH CLOSED LOWS, AND GENERAL LOW MEDIUM RANGE
PREDICTABILITY THIS WINTER, WILL SIMPLY ALLOW THE BLENDED EXTENDED
GRIDS TO SPEAK FOR THEMSELVES AT THIS POINT.

MARINE...

FRESH TO STRONG SOUTHERLY WINDS WILL PERSIST FOR THE NEXT FEW HOURS
AS A WEAK LOW APPROACHES FROM THE WEST. GUSTS WILL BE LIMITED TO
AROUND 30 KNOTS GIVEN THE STABILITY OF WARM SOUTH FLOW. WINDS WILL
VEER TO THE NORTHWEST AND INCREASE CONSIDERABLY THIS EVENING INTO
TONIGHT. WIDESPREAD GALES ARE EXPECTED OVER LAKE HURON WITH GUSTS TO
STRONG GALES EXPECTED OVER CENTRAL AND SOUTHERN LAKE HURON WHERE
SIGNIFICANT WAVE HEIGHTS WILL EXCEED 12 FEET WITH HIGHER MAXIMUM
WAVE HEIGHTS. THE GALE WATCH HAS THEREFORE BEEN UPGRADED TO A
WARNING. CONSIDERABLE HEAVY FREEZING SPRAY WILL ACCOMPANY THESE
CONDITIONS AND A WARNING HAS BEEN ISSUED ACCORDINGLY. WINDS AND
WAVES WILL SUBSIDE FRIDAY AFTERNOON INTO FRIDAY NIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 10 AM EST
     FRIDAY FOR LHZ362-363-421-441-462.

     GALE WARNING FROM 7 PM THIS EVENING TO 10 AM EST FRIDAY FOR LHZ362-
     363-421-441-462.

     HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 10 AM EST
     FRIDAY FOR LHZ442-443-463-464.

     GALE WARNING FROM 10 PM THIS EVENING TO 10 AM EST FRIDAY FOR LHZ442-
     443-463-464.

     HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 4 AM EST
     FRIDAY FOR LHZ361.

     GALE WARNING FROM 7 PM THIS EVENING TO 4 AM EST FRIDAY FOR LHZ361.

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

$$

AVIATION.....DG
SHORT TERM...DG
LONG TERM....JVC
MARINE.......JVC


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





000
FXUS63 KDTX 290742
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
242 AM EST THU JAN 29 2015

.SHORT TERM...TODAY AND TONIGHT

A SHORTWAVE WILL TRACK FROM THE MID MISSISSIPPI VALLEY INTO THE
CENTRAL GREAT LAKES TODAY...SPREADING MOISTURE INTO THE AREA EARLY
THIS MORNING. 00Z KDTX SOUNDING SHOWS A VERY DRY LAYER IN PLACE OVER
LOWER MICHIGAN FROM 750 MB DOWN TO THE SURFACE...WHICH HAS KEPT A
BAND OF MOISTURE WITHIN REGION OF ISENTROPIC ASCENT IN ADVANCE OF
THIS THE MAIN SYSTEM ELEVATED OVERNIGHT.

FORCING ALONG THE LEAD EDGE OF THE VORTICITY CENTER WILL PROGRESS
EAST TO NORTHEAST INTO THE AREA FROM ITS CURRENTLY POSITION FROM
SOUTHWEST LOWER MICHIGAN INTO NORTHERN INDIANA. HOWEVER...BETWEEN
THE DRY LOW LEVELS STILL IN PLACE IN ADVANCE OF THIS BAND OF RAIN
AND SNOW...AND A MID LEVEL DRY SLOT TRAILING THIS FEATURE INTO THE
AREA...PRECIPITATION INTENSITY AND DURATION WILL BE LIMITED EARLY
THIS MORNING OVER MUCH OF THE CWA. ONLY THE NORTHERN THIRD TO HALF
OF THE CWA MAY RECEIVE 3 OR 4 HOURS OF PRECIPITATION...MAINLY SLEET
OR SNOW...ALONG THE NORTHERN EDGE OF THE DRY SLOT.

FURTHER SOUTH INTO METRO DETROIT AND POINTS SOUTH...A BRIEF ONE OR
TWO HOUR PERIOD OF LIGHT SHOWERS OR SLEET WILL CROSS THE AREA. WITH
TEMPERATURES IN THE MID 20S...ANY LIQUID THAT DOES FALL WILL MOST
LIKELY FREEZE ON SURFACES. AT THIS TIME...ONLY PATCHY SLICK SPOTS
ARE EXPECTED GIVEN THE LACK OF COVERAGE OF THE THE PRECIPITATION.
NO HEADLINES ARE ANTICIPATED AT THIS TIME.

AS THE SHORTWAVE CROSSES THE AREA TODAY...ADDITIONAL SNOW SHOWERS
WILL OCCUR AS COLDER AIR ASSOCIATED WITH THE WAVE OVERSPREADS THE
AREA. TEMPERATURES AT THE SURFACE WILL REMAIN AOA FREEZING FOR MUCH
OF THE AREA FROM LATE MORNING INTO THE AFTERNOON AS STRONGER COLD
AIR ADVECTION HOLDS OFF UNTIL THIS EVENING AND TONIGHT. TOTAL SNOW
ACCUMULATIONS OF AN INCH OR TWO WILL BE POSSIBLE DURING THE ENTIRE
PERIOD OVER THE NORTHERN CWA WITH MUCH LESSER AMOUNTS SOUTHWARD FROM
METRO DETROIT TO THE MICHIGAN AND OHIO STATE LINE.

COLD AIR WILL FILTER BACK SOUTH INTO THE AREA TONIGHT WITH THE LOW
TEMPERATURES RANGING FROM THE SINGLE DIGITS TO AROUND 10 DEGREE OVER
THE NORTH TO THE LOW/MID TEENS I-94 SOUTH. ANY REMAINING SNOW
SHOWERS WILL BE INSIGNIFICANT.

&&

.LONG TERM...

ARCTIC HIGH PRESSURE BUTTED AGAINST THE FRONT RANGE OF THE ROCKIES
IN ALBERTA THIS MORNING IS INTENSIFYING AS SHORTWAVE RIDGING
DEVELOPS DOWNSTREAM OF THE ALEUTIAN LOW. COLLAPSE OF UPPER SUPPORT
DUE TO INCREASING CONFLUENCE OVER NORTHWEST CANADA WILL FORCE THE
HIGH TO WEAKEN AND QUICKLY TRANSLATE SOUTHEAST INTO THE UPPER
MIDWEST THIS MORNING BEFORE SETTLING OVER THE OHIO VALLEY TONIGHT.
THIS WILL DRIVE A PERSISTENT NW GRADIENT ACROSS THE CWA THROUGH THE
FIRST HALF OF FRIDAY. COLD ADVECTION WILL EASE AS THE BROAD SURFACE
RIDGE AXIS TRAVERSES THE AREA, BUT WITH 925MB TEMPERATURES HOVERING
NEAR -17C, HIGHS WILL BE STUCK IN THE TEENS ON FRIDAY. RAPID
EASTWARD PROGRESS OF THE HIGH AND DRY NW FLOW, SUPPORTED BY
RELATIVELY DRY MOISTURE FIELDS IN THE 00Z NAM, SUGGEST THAT THIS
WILL BE THE CASE EVEN IN THE PRESENCE OF MOSTLY SUNNY SKIES OVER
MOST OF THE AREA. THE POTENTIAL EXCEPTION MAY BE ACROSS THE FAR NW
WHERE LAKE SUPERIOR-MICHIGAN PLUME WILL POTENTIALLY CONTRIBUTE TO A
MORE PERSISTENT STRATOCU DECK. FOR THIS SAME REASON, LOWS SHOULD
EASILY FALL INTO THE SINGLE DIGITS FRIDAY NIGHT, BUT HAVE A HIGHER
LIKELIHOOD OF REMAINING IN THE 10-15 DEGREES ACROSS THE FAR WEST.

A MOISTURE STARVED WAVE EMBEDDED IN NW FLOW WILL RACE ACROSS THE
GREAT LAKES EARLY FRIDAY BRINGING NOTHING MORE THAN A FEW SNOW
SHOWERS ACROSS THE FAR NORTH WITH NO ACCUMULATION EXPECTED.
DEVELOPING RETURN FLOW WILL PUSH HIGHS INTO AT LEAST THE UPPER 20S.

HIGH UNCERTAINTY FOR THE SECOND HALF OF THE WEEKEND. A SHORTWAVE,
WHICH HAS YET TO ACTUALLY DEVELOP, IS FORECAST BY THE SUITE OF
GUIDANCE TO EMERGE OUT OF THE ALEUTIAN LOW LATE TONIGHT AND COME
ONSHORE IN BRITISH COLUMBIA ON FRIDAY EVENING. THIS WAVE WILL
QUICKLY SHEAR TO SOUTHEAST AND INTERACT TO SOME DEGREE WITH A CLOSED
LOW OVER THE BAJA.

WHAT IS KNOWN IS THAT THERE IS A REASONABLE LIKELIHOOD FOR A
PROLONGED PERIOD OF LIGHT TO MODERATE ACCUMULATING SNOW TO DEVELOP
OVER A WIDE AREA GIVEN GIVEN THE BROAD AREA OF ISENTROPIC ASCENT AND
NORTHWARD TRANSPORT OF 4-5 G/KG H7 SPECIFIC HUMIDITY COURTESY OF
SOUTHERN STREAM INVOLVEMENT. THE KEY PLAYER IN THE LOCAL FORECAST
WILL BE JUST HOW AGGRESSIVELY THE NORTHERN BRANCH DIGS OVER MONTANA,
WYOMING, AND COLORADO SATURDAY INTO SATURDAY NIGHT. THE GREATER THE
INTERACTION WITH THE CLOSED LOW, THE GREATER SNOW PROSPECTS BECOME.
AS IT STANDS, THE NAM AND GEM ARE BY FAR THE MOST AGGRESSIVE. THE
ECMWF AND GFS ARE CONSIDERABLY LESS SO AND CONFINE ACCUMULATING SNOW
SOUTH OF THE OHIO BORDER. HOWEVER, THE LATTER TWO STILL MADE
NOTEWORTHY MOVES TOWARD MORE AGGRESSIVE SOLUTIONS AT 00Z IN
COMPARISON TO THEIR 12Z COUNTERPARTS. 00Z GFS ENSEMBLES ARE SPLIT
BETWEEN NORTH/SOUTH SOLUTIONS WITH THE OPERATIONAL GFS AND TWO
CONTROL RUNS REMAINING RIGHT IN BETWEEN AND CENTERING THE ACTION
ALONG/SOUTH OF I-80. GIVEN THAT THE S/W HAS YET TO EMERGE, TYPICAL
NWP PROBLEMS WITH CLOSED LOWS, AND GENERAL LOW MEDIUM RANGE
PREDICTABILITY THIS WINTER, WILL SIMPLY ALLOW THE BLENDED EXTENDED
GRIDS TO SPEAK FOR THEMSELVES AT THIS POINT.

&&

.MARINE...

FRESH TO STRONG SOUTHERLY WINDS WILL PERSIST FOR THE NEXT FEW HOURS
AS A WEAK LOW APPROACHES FROM THE WEST. GUSTS WILL BE LIMITED TO
AROUND 30 KNOTS GIVEN THE STABILITY OF WARM SOUTH FLOW. WINDS WILL
VEER TO THE NORTHWEST AND INCREASE CONSIDERABLY THIS EVENING INTO
TONIGHT. WIDESPREAD GALES ARE EXPECTED OVER LAKE HURON WITH GUSTS TO
STRONG GALES EXPECTED OVER CENTRAL AND SOUTHERN LAKE HURON WHERE
SIGNIFICANT WAVE HEIGHTS WILL EXCEED 12 FEET WITH HIGHER MAXIMUM
WAVE HEIGHTS. THE GALE WATCH HAS THEREFORE BEEN UPGRADED TO A
WARNING. CONSIDERABLE HEAVY FREEZING SPRAY WILL ACCOMPANY THESE
CONDITIONS AND A WARNING HAS BEEN ISSUED ACCORDINGLY. WINDS AND
WAVES WILL SUBSIDE FRIDAY AFTERNOON INTO FRIDAY NIGHT.

&&

.AVIATION...ISSUED 1158 PM EST WED JAN 28 2015

AN APPROACHING LOW WILL BRING PROGRESSIVELY LOWER CEILINGS AS IT
APPROACHES THE CENTRAL GREAT LAKES DURING THE EARLY MORNING HOURS.
THIS LOW LEVEL SYSTEM WILL BRING A MIX OF RAIN/SLEET/SNOW TO THE
REGION STARTING ROUGHLY AROUND 12Z. AN EARLIER ARRIVAL OF THE
FORCING AND A COLDER THERMAL PROFILE SUGGESTS ALL SNOW AT
MBS...STARTING AROUND OR SHORTLY AFTER 09Z. COLD AIR WRAPPING IN
BEHIND THE DEPARTING LOW WILL CHANGE THE MIXED PRECIPITATION BACK
OVER TO ALL SNOW DURING THE AFTERNOON HOURS BEFORE WINDING DOWN
DURING THURSDAY EVENING. AN INCH OR TWO OF SNOW IS POSSIBLE AT FNT
AND MBS...WITH LESS THAN AN INCH FROM PTK SOUTH TO THE METRO
AIRPORTS. VERY GUSTY NORTHWEST WINDS OF 25 TO 30 KNOTS ARE EXPECTED
BEHIND THE LOW LATE THIS AFTERNOON AND INTO THURSDAY EVENING AS THE
COLD AIR RUSHES SOUTHWARD.

FOR DTW...CONSIDERING THE DEGREE OF WARM AIR ALOFT FORECAST TO
OVERSPREAD METRO DETROIT...PRECIP IS EXPECTED TO START MAINLY AS
FREEZING RAIN. IT SHOULD TRANSITION OVER TO PURE RAIN DURING THE
COURSE OF THE MORNING AS SFC TEMPS WARM ABOVE FREEZING.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT AFTER 10Z.

* MEDIUM IN PRECIP TYPE STARTING AS A FZRA/IP MIX THIS MORNING.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 10 AM EST
     FRIDAY FOR LHZ362-363-421-441-462.

     GALE WARNING FROM 7 PM THIS EVENING TO 10 AM EST FRIDAY FOR LHZ362-
     363-421-441-462.

     HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 10 AM EST
     FRIDAY FOR LHZ442-443-463-464.

     GALE WARNING FROM 10 PM THIS EVENING TO 10 AM EST FRIDAY FOR LHZ442-
     443-463-464.

     HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 4 AM EST
     FRIDAY FOR LHZ361.

     GALE WARNING FROM 7 PM THIS EVENING TO 4 AM EST FRIDAY FOR LHZ361.

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

$$

SHORT TERM...DG
LONG TERM....JVC
MARINE.......JVC
AVIATION.....KURIMSKI


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




000
FXUS63 KDTX 290742
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
242 AM EST THU JAN 29 2015

.SHORT TERM...TODAY AND TONIGHT

A SHORTWAVE WILL TRACK FROM THE MID MISSISSIPPI VALLEY INTO THE
CENTRAL GREAT LAKES TODAY...SPREADING MOISTURE INTO THE AREA EARLY
THIS MORNING. 00Z KDTX SOUNDING SHOWS A VERY DRY LAYER IN PLACE OVER
LOWER MICHIGAN FROM 750 MB DOWN TO THE SURFACE...WHICH HAS KEPT A
BAND OF MOISTURE WITHIN REGION OF ISENTROPIC ASCENT IN ADVANCE OF
THIS THE MAIN SYSTEM ELEVATED OVERNIGHT.

FORCING ALONG THE LEAD EDGE OF THE VORTICITY CENTER WILL PROGRESS
EAST TO NORTHEAST INTO THE AREA FROM ITS CURRENTLY POSITION FROM
SOUTHWEST LOWER MICHIGAN INTO NORTHERN INDIANA. HOWEVER...BETWEEN
THE DRY LOW LEVELS STILL IN PLACE IN ADVANCE OF THIS BAND OF RAIN
AND SNOW...AND A MID LEVEL DRY SLOT TRAILING THIS FEATURE INTO THE
AREA...PRECIPITATION INTENSITY AND DURATION WILL BE LIMITED EARLY
THIS MORNING OVER MUCH OF THE CWA. ONLY THE NORTHERN THIRD TO HALF
OF THE CWA MAY RECEIVE 3 OR 4 HOURS OF PRECIPITATION...MAINLY SLEET
OR SNOW...ALONG THE NORTHERN EDGE OF THE DRY SLOT.

FURTHER SOUTH INTO METRO DETROIT AND POINTS SOUTH...A BRIEF ONE OR
TWO HOUR PERIOD OF LIGHT SHOWERS OR SLEET WILL CROSS THE AREA. WITH
TEMPERATURES IN THE MID 20S...ANY LIQUID THAT DOES FALL WILL MOST
LIKELY FREEZE ON SURFACES. AT THIS TIME...ONLY PATCHY SLICK SPOTS
ARE EXPECTED GIVEN THE LACK OF COVERAGE OF THE THE PRECIPITATION.
NO HEADLINES ARE ANTICIPATED AT THIS TIME.

AS THE SHORTWAVE CROSSES THE AREA TODAY...ADDITIONAL SNOW SHOWERS
WILL OCCUR AS COLDER AIR ASSOCIATED WITH THE WAVE OVERSPREADS THE
AREA. TEMPERATURES AT THE SURFACE WILL REMAIN AOA FREEZING FOR MUCH
OF THE AREA FROM LATE MORNING INTO THE AFTERNOON AS STRONGER COLD
AIR ADVECTION HOLDS OFF UNTIL THIS EVENING AND TONIGHT. TOTAL SNOW
ACCUMULATIONS OF AN INCH OR TWO WILL BE POSSIBLE DURING THE ENTIRE
PERIOD OVER THE NORTHERN CWA WITH MUCH LESSER AMOUNTS SOUTHWARD FROM
METRO DETROIT TO THE MICHIGAN AND OHIO STATE LINE.

COLD AIR WILL FILTER BACK SOUTH INTO THE AREA TONIGHT WITH THE LOW
TEMPERATURES RANGING FROM THE SINGLE DIGITS TO AROUND 10 DEGREE OVER
THE NORTH TO THE LOW/MID TEENS I-94 SOUTH. ANY REMAINING SNOW
SHOWERS WILL BE INSIGNIFICANT.

&&

.LONG TERM...

ARCTIC HIGH PRESSURE BUTTED AGAINST THE FRONT RANGE OF THE ROCKIES
IN ALBERTA THIS MORNING IS INTENSIFYING AS SHORTWAVE RIDGING
DEVELOPS DOWNSTREAM OF THE ALEUTIAN LOW. COLLAPSE OF UPPER SUPPORT
DUE TO INCREASING CONFLUENCE OVER NORTHWEST CANADA WILL FORCE THE
HIGH TO WEAKEN AND QUICKLY TRANSLATE SOUTHEAST INTO THE UPPER
MIDWEST THIS MORNING BEFORE SETTLING OVER THE OHIO VALLEY TONIGHT.
THIS WILL DRIVE A PERSISTENT NW GRADIENT ACROSS THE CWA THROUGH THE
FIRST HALF OF FRIDAY. COLD ADVECTION WILL EASE AS THE BROAD SURFACE
RIDGE AXIS TRAVERSES THE AREA, BUT WITH 925MB TEMPERATURES HOVERING
NEAR -17C, HIGHS WILL BE STUCK IN THE TEENS ON FRIDAY. RAPID
EASTWARD PROGRESS OF THE HIGH AND DRY NW FLOW, SUPPORTED BY
RELATIVELY DRY MOISTURE FIELDS IN THE 00Z NAM, SUGGEST THAT THIS
WILL BE THE CASE EVEN IN THE PRESENCE OF MOSTLY SUNNY SKIES OVER
MOST OF THE AREA. THE POTENTIAL EXCEPTION MAY BE ACROSS THE FAR NW
WHERE LAKE SUPERIOR-MICHIGAN PLUME WILL POTENTIALLY CONTRIBUTE TO A
MORE PERSISTENT STRATOCU DECK. FOR THIS SAME REASON, LOWS SHOULD
EASILY FALL INTO THE SINGLE DIGITS FRIDAY NIGHT, BUT HAVE A HIGHER
LIKELIHOOD OF REMAINING IN THE 10-15 DEGREES ACROSS THE FAR WEST.

A MOISTURE STARVED WAVE EMBEDDED IN NW FLOW WILL RACE ACROSS THE
GREAT LAKES EARLY FRIDAY BRINGING NOTHING MORE THAN A FEW SNOW
SHOWERS ACROSS THE FAR NORTH WITH NO ACCUMULATION EXPECTED.
DEVELOPING RETURN FLOW WILL PUSH HIGHS INTO AT LEAST THE UPPER 20S.

HIGH UNCERTAINTY FOR THE SECOND HALF OF THE WEEKEND. A SHORTWAVE,
WHICH HAS YET TO ACTUALLY DEVELOP, IS FORECAST BY THE SUITE OF
GUIDANCE TO EMERGE OUT OF THE ALEUTIAN LOW LATE TONIGHT AND COME
ONSHORE IN BRITISH COLUMBIA ON FRIDAY EVENING. THIS WAVE WILL
QUICKLY SHEAR TO SOUTHEAST AND INTERACT TO SOME DEGREE WITH A CLOSED
LOW OVER THE BAJA.

WHAT IS KNOWN IS THAT THERE IS A REASONABLE LIKELIHOOD FOR A
PROLONGED PERIOD OF LIGHT TO MODERATE ACCUMULATING SNOW TO DEVELOP
OVER A WIDE AREA GIVEN GIVEN THE BROAD AREA OF ISENTROPIC ASCENT AND
NORTHWARD TRANSPORT OF 4-5 G/KG H7 SPECIFIC HUMIDITY COURTESY OF
SOUTHERN STREAM INVOLVEMENT. THE KEY PLAYER IN THE LOCAL FORECAST
WILL BE JUST HOW AGGRESSIVELY THE NORTHERN BRANCH DIGS OVER MONTANA,
WYOMING, AND COLORADO SATURDAY INTO SATURDAY NIGHT. THE GREATER THE
INTERACTION WITH THE CLOSED LOW, THE GREATER SNOW PROSPECTS BECOME.
AS IT STANDS, THE NAM AND GEM ARE BY FAR THE MOST AGGRESSIVE. THE
ECMWF AND GFS ARE CONSIDERABLY LESS SO AND CONFINE ACCUMULATING SNOW
SOUTH OF THE OHIO BORDER. HOWEVER, THE LATTER TWO STILL MADE
NOTEWORTHY MOVES TOWARD MORE AGGRESSIVE SOLUTIONS AT 00Z IN
COMPARISON TO THEIR 12Z COUNTERPARTS. 00Z GFS ENSEMBLES ARE SPLIT
BETWEEN NORTH/SOUTH SOLUTIONS WITH THE OPERATIONAL GFS AND TWO
CONTROL RUNS REMAINING RIGHT IN BETWEEN AND CENTERING THE ACTION
ALONG/SOUTH OF I-80. GIVEN THAT THE S/W HAS YET TO EMERGE, TYPICAL
NWP PROBLEMS WITH CLOSED LOWS, AND GENERAL LOW MEDIUM RANGE
PREDICTABILITY THIS WINTER, WILL SIMPLY ALLOW THE BLENDED EXTENDED
GRIDS TO SPEAK FOR THEMSELVES AT THIS POINT.

&&

.MARINE...

FRESH TO STRONG SOUTHERLY WINDS WILL PERSIST FOR THE NEXT FEW HOURS
AS A WEAK LOW APPROACHES FROM THE WEST. GUSTS WILL BE LIMITED TO
AROUND 30 KNOTS GIVEN THE STABILITY OF WARM SOUTH FLOW. WINDS WILL
VEER TO THE NORTHWEST AND INCREASE CONSIDERABLY THIS EVENING INTO
TONIGHT. WIDESPREAD GALES ARE EXPECTED OVER LAKE HURON WITH GUSTS TO
STRONG GALES EXPECTED OVER CENTRAL AND SOUTHERN LAKE HURON WHERE
SIGNIFICANT WAVE HEIGHTS WILL EXCEED 12 FEET WITH HIGHER MAXIMUM
WAVE HEIGHTS. THE GALE WATCH HAS THEREFORE BEEN UPGRADED TO A
WARNING. CONSIDERABLE HEAVY FREEZING SPRAY WILL ACCOMPANY THESE
CONDITIONS AND A WARNING HAS BEEN ISSUED ACCORDINGLY. WINDS AND
WAVES WILL SUBSIDE FRIDAY AFTERNOON INTO FRIDAY NIGHT.

&&

.AVIATION...ISSUED 1158 PM EST WED JAN 28 2015

AN APPROACHING LOW WILL BRING PROGRESSIVELY LOWER CEILINGS AS IT
APPROACHES THE CENTRAL GREAT LAKES DURING THE EARLY MORNING HOURS.
THIS LOW LEVEL SYSTEM WILL BRING A MIX OF RAIN/SLEET/SNOW TO THE
REGION STARTING ROUGHLY AROUND 12Z. AN EARLIER ARRIVAL OF THE
FORCING AND A COLDER THERMAL PROFILE SUGGESTS ALL SNOW AT
MBS...STARTING AROUND OR SHORTLY AFTER 09Z. COLD AIR WRAPPING IN
BEHIND THE DEPARTING LOW WILL CHANGE THE MIXED PRECIPITATION BACK
OVER TO ALL SNOW DURING THE AFTERNOON HOURS BEFORE WINDING DOWN
DURING THURSDAY EVENING. AN INCH OR TWO OF SNOW IS POSSIBLE AT FNT
AND MBS...WITH LESS THAN AN INCH FROM PTK SOUTH TO THE METRO
AIRPORTS. VERY GUSTY NORTHWEST WINDS OF 25 TO 30 KNOTS ARE EXPECTED
BEHIND THE LOW LATE THIS AFTERNOON AND INTO THURSDAY EVENING AS THE
COLD AIR RUSHES SOUTHWARD.

FOR DTW...CONSIDERING THE DEGREE OF WARM AIR ALOFT FORECAST TO
OVERSPREAD METRO DETROIT...PRECIP IS EXPECTED TO START MAINLY AS
FREEZING RAIN. IT SHOULD TRANSITION OVER TO PURE RAIN DURING THE
COURSE OF THE MORNING AS SFC TEMPS WARM ABOVE FREEZING.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT AFTER 10Z.

* MEDIUM IN PRECIP TYPE STARTING AS A FZRA/IP MIX THIS MORNING.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 10 AM EST
     FRIDAY FOR LHZ362-363-421-441-462.

     GALE WARNING FROM 7 PM THIS EVENING TO 10 AM EST FRIDAY FOR LHZ362-
     363-421-441-462.

     HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 10 AM EST
     FRIDAY FOR LHZ442-443-463-464.

     GALE WARNING FROM 10 PM THIS EVENING TO 10 AM EST FRIDAY FOR LHZ442-
     443-463-464.

     HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 4 AM EST
     FRIDAY FOR LHZ361.

     GALE WARNING FROM 7 PM THIS EVENING TO 4 AM EST FRIDAY FOR LHZ361.

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

$$

SHORT TERM...DG
LONG TERM....JVC
MARINE.......JVC
AVIATION.....KURIMSKI


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





000
FXUS63 KDTX 290458
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1158 PM EST WED JAN 28 2015


.AVIATION...

AN APPROACHING LOW WILL BRING PROGRESSIVELY LOWER CEILINGS AS IT
APPROACHES THE CENTRAL GREAT LAKES DURING THE EARLY MORNING HOURS.
THIS LOW LEVEL SYSTEM WILL BRING A MIX OF RAIN/SLEET/SNOW TO THE
REGION STARTING ROUGHLY AROUND 12Z. AN EARLIER ARRIVAL OF THE
FORCING AND A COLDER THERMAL PROFILE SUGGESTS ALL SNOW AT
MBS...STARTING AROUND OR SHORTLY AFTER 09Z. COLD AIR WRAPPING IN
BEHIND THE DEPARTING LOW WILL CHANGE THE MIXED PRECIPITATION BACK
OVER TO ALL SNOW DURING THE AFTERNOON HOURS BEFORE WINDING DOWN
DURING THURSDAY EVENING. AN INCH OR TWO OF SNOW IS POSSIBLE AT FNT
AND MBS...WITH LESS THAN AN INCH FROM PTK SOUTH TO THE METRO
AIRPORTS. VERY GUSTY NORTHWEST WINDS OF 25 TO 30 KNOTS ARE EXPECTED
BEHIND THE LOW LATE THIS AFTERNOON AND INTO THURSDAY EVENING AS THE
COLD AIR RUSHES SOUTHWARD.

FOR DTW...CONSIDERING THE DEGREE OF WARM AIR ALOFT FORECAST TO
OVERSPREAD METRO DETROIT...PRECIP IS EXPECTED TO START MAINLY AS
FREEZING RAIN. IT SHOULD TRANSITION OVER TO PURE RAIN DURING THE
COURSE OF THE MORNING AS SFC TEMPS WARM ABOVE FREEZING.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT AFTER 10Z.

* MEDIUM IN PRECIP TYPE STARTING AS A FZRA/IP MIX THIS MORNING.

&&

.PREV DISCUSSION...ISSUED 353 PM EST WED JAN 28 2015

SHORT TERM...THIS EVENING

A DEPARTING LOW LEVEL ANTICYCLONE HAS MAINTAINED AMPLE LOW LEVEL DRY
AIR ACROSS SE MI TODAY. LIGHT S-SE RETURN FLOW HAS IN TURN ALLOWED
TEMPS TO RISE INTO THE UPPER 20S/LOW 30S. HIGH CLOUDS WILL BE ON THE
INCREASE DURING THE REST OF THE AFTERNOON...FOLLOWED BY INCREASING
MID LEVEL CLOUDS THIS EVENING. THIS WILL OCCUR AS THE BROAD RIBBON
OF WARM AIR ADVECTION/MID LEVEL MOISTURE TRANSPORT NOW EXPANDING
ACROSS THE WRN GREAT LAKES CONTINUES TO ADVANCE TO THE EAST. THERE
SHOULD BE JUST ENOUGH DECOUPLING IN THE BOUNDARY LAYER TO SUPPORT
SOME DEGREE OF TEMP DROP THIS EVENING. STRENGTHENING LOW LEVEL
SOUTHERLY FLOW AHEAD OF A SFC LOW WILL DRIVE WARMER AIR IN DURING
THE NIGHT. THIS ALONG WITH INCREASING CLOUDS WILL LEAD TO A SLOW
WARMING TREND AFTER MIDNIGHT.

LONG TERM...LATE TONIGHT THROUGH NEXT WEDNESDAY

THE BEST SHOT AT PRECIP IN THE COMING WEEK ARRIVES RIGHT AWAY ON
THURSDAY AS A PAIR OF WAVES ATTEMPTS TO PHASE OVER THE REGION. LOW
AMPLITUDE LONG WAVE PATTERN ACROSS THE WEST/CENTRAL CONUS WILL
TRANSITION TO DEEP TROUGHING OVER THE EASTERN CONUS. THIS WILL OCCUR
AS ENERGY RELEASED FROM THE ALASKAN BAY LOW SURGES DOWN INTO THE
MIDWEST. A CURRENT SOUTHERN STREAM WAVE AND RESULTANT SFC LOW OVER
THE CENTRAL PLAINS WILL TRACK EASTERLY THE SOUTHERN GREAT LAKES
THURSDAY...LOOKING TO STAY JUST AHEAD OF THE FIRST NOTABLE NORTHERN
STREAM WAVE. THIS INTERACTION IS KEY TO HOW THE SYSTEM WILL PLAY OUT
FOR SE MI. THE SLOWER THE NORTHERN STREAM WAVE IS...THE MORE LIKELY
THE SOUTHERN STREAM WAVE WILL REMAIN IN TACK...VS A FASTER WAVE
CATCHING UP AND PHASING DIRECTLY OVERHEAD. THIS WOULD DISRUPT THE
LOW...SHEARING IT NORTH/SOUTH THROUGH THE REGION AS IT TRIES TO
REDEVELOP FURTHER DOWNSTREAM. IN THE END...MODEL SUITE HAS TRENDED
TOWARD KEEPING SOME SEPARATION BETWEEN THE SYSTEMS...THUS HAVE
ADJUSTED THE FORECAST ACCORDINGLY. THE DETAILS TO FOLLOW...

WITH THE CENTRAL PLAINS SFC LOW BEING LESS AFFECTED BY THE INCOMING
WAVE/JET MAX INTO SOUTHERN MI...THE LOW WILL BE ABLE TO MAINTAIN
MORE OF ITS STRUCTURE/FORCING. THIS IS ALREADY BEING SHOWN IN THE
MODELS BY KEEPING THE STRONG BAND OF ISENTROPIC ASCENT IN TACK AS IT
LIFTS THROUGH SW/CENTRAL MI EARLY THURSDAY MORNING AND THE
DEFORMATION BAND AS IT SWINGS THROUGH THURSDAY AFTERNOON. IT ALSO
KEEPS BRINGS THE NOSE OF A THETA E PLUME UP THROUGH THE AREA BETWEEN
12-18Z WITH A DECENT GRADIENT ON THE LEAD EDGE. A DEEP LAYER OF DRY
AIR FROM THE SFC TO 700MB IN PLACE WEDNESDAY NIGHT WILL HOLD BACK
MUCH OF THE PRECIP TIL AFTER 12Z MONDAY...AT LEAST FOR LOCATIONS
EAST OF I75. THE LEAD ISENTROPIC LIFT ON THE NE SIDE OF THE LOW WILL
LIFT THROUGH THE SAGINAW BAY FROM ABOUT 09-12Z. THIS WILL GIVE THAT
AREA AROUND A HALF INCH OF SNOWFALL FOR THE MORNING COMMUTE WHILE
BEGINNING TO SATURATE THE LOW LEVELS ACROSS THE REST OF THE REGION.
AFTER 12Z...STRONG SW FLOW IN THE LOW LEVELS PROMOTES GOOD WAA IN
THE 900-800MB LAYER WITH TEMPS GOING NEARLY ISOTHERMAL IN THE LAYER
RIGHT AROUND 0C. MODELS VARY A DEGREE OR TWO WITH THE LL THERMAL
PROFILE IN THE 12-18Z TIMEFRAME. THIS LEADS TO A COMPLICATED MIXED
PRECIP SCENARIO OVER SOUTHERN MI INTO THE EARLY AFTERNOON. THE MIXED
PRECIP WILL END LATER IN THE AFTERNOON OR EARLY EVENING AS STRONG
CAA SURGES IN FROM THE NW BEHIND THE NORTHERN STREAM TROUGH. THIS
WILL TURN THE REMAINING PRECIP...MAINLY IN THE DEFORMATION
BAND...INTO ALL SNOW FOR THE TAIL END OF THE EVENT. LOOKING FOR A
POSSIBLE INCH OVER THE THUMB AS THE BAND SWEEPS THROUGH WITH LESS
THAN A HALF INCH FURTHER SOUTH NEAR DETROIT. MODELS ARE PRETTY WELL
IN LINE WITH QPF FOR THE EVENT...WHICH HAS NOT CHANGED MUCH OVER THE
LAST FEW MODEL RUNS...MAINTAINING AROUND 0.25 INCHES ACROSS THE
NORTH AND AROUND 0.15-0.20 INCHES ACROSS THE SOUTH. THE WARM AIR
ALOFT WILL REALLY CUT INTO SNOWFALL TOTALS ACROSS THE
AREA...ESPECIALLY SOUTH OF M59 WHERE A MIX OF FREEZING RAIN AND
SLEET WILL LIKELY OCCUR FOR SEVERAL HOURS BEFORE CAA COOLS THE
ENVIRONMENT ENOUGH FOR SNOW. NOT EXPECTING MUCH IN THE WAY OF ICE
ACCUMULATION AS THIS AREA WILL WARM INTO THE MID 30S WITH RAIN
POSSIBLE BY AFTERNOON. LOCATIONS BETWEEN I69 AND M59 WILL LIKELY SEE
MORE OF A SNOW/SLEET MIX RESULTING IN MINOR ACCUMULATIONS OF 1-2
INCHES. NORTH OF I69 STANDS THE BEST CHANCE TO SEE A PURE SNOW
EVENT...BUT WITH LOW SNOWFALL RATIOS WILL LIKELY ONLY AMOUNT TO 2-3
INCHES.

ONCE THE PRECIP ENDS THURSDAY NIGHT...A SECOND COLD FRONT WILL SWEEP
THROUGH DOWN THROUGH MI DROPPING 850MB TEMPS TO 15C. EVEN WITH HIGH
PRESSURE AND A GOOD DEAL OF SUNSHINE FRIDAY AFTERNOON...HIGH
TEMPERATURES WILL LIKELY ONLY RISE INTO THE TEENS. LOWS FRIDAY NIGHT
WILL DIP BACK INTO THE SINGLE DIGITS.

AS FAR AS THIS WEEKEND...MODELS ARE AGAIN JUMPING BACK AND FORTH ON
THE TRACK FOR THE SUNDAY SYSTEM.  LATEST MODEL RUNS ARE INDICATING A
WEAKER AND MORE SOUTHERN TRACK WITH THE MAIN JET ENERGY AND
SHORTWAVE ASSOCIATED WITH THIS SYSTEM STAYING TO THE SOUTH OF THE
AREA.  SEEING THE MODEL SOLUTIONS VARYING...HAVE GONE WITH CHANCE
POPS UNTIL MODELS COME TO INTO BETTER CONSENSUS.  AT THIS
POINT...THE BETTER LOCATIONS FOR SEEING ANY SNOW WOULD LIKELY BE
AREAS CLOSER TO THE OHIO BORDER.  COLDER TEMPS WILL HANG AROUND AS
THE GREAT LAKES REGION REMAINS IN THE LONGWAVE TROUGH THROUGH THE
REMAINDER OF THE EXTENDED.

MARINE...

SOUTH-SOUTHEASTERLY WINDS WILL BE ON THE INCREASE TONIGHT AS LOW
PRESSURE APPROACHES FROM THE WEST. THE RESULTING WARM AIR ADVECTION
WILL INHIBIT THE DEGREE OF MIXING OVER THE LAKES. SO ALTHOUGH MODEL
SOLUTIONS SUGGEST GALE FORCE WINDS DOWN TO 1K FT...THE SHALLOW
STABLE LAYER OVER THE LAKES WILL INHIBIT THE POTENTIAL FOR GALE
FORCE WIND GUSTS TO OCCUR OVER A PERIOD GREATER THAN THREE HOURS.
THIS SUGGESTS THAT A GALE WARNING FOR TONIGHT WILL NOT BE NEEDED.
ALTHOUGH FREQUENT GUSTS TO 30 KNOTS ARE EXPECTED...MAINLY LATE
TONIGHT THROUGH THURS MORNING. WINDS WILL DECREASE THURS AFTERNOON
AS THE SURFACE LOW TRACKS OVERHEAD AND THEN VEER TO THE WEST-
NORTHWEST LATE THURS AS THE LOW HEADS EAST OF LAKE HURON. ARCTIC AIR
WILL THEN INFILTRATE THE REGION WITH THE DEPARTURE OF THE SFC LOW.
THIS WILL BOOST MIXING DEPTHS OVER THE LAKE AND WILL SUPPORT GALE
FORCE WINDS GUSTS THURS NIGHT INTO FRIDAY MORNING AND LAKE HURON
BEFORE THE GRADIENT WEAKENS SUBSTANTIALLY FRI AFTERNOON. THE GALE
WATCH WILL REMAIN IN PLACE FOR LAKE HURON WITH GROWING CONFIDENCE
THAT THIS WILL BE UPGRADED TO A GALE WARNING EITHER THIS EVENING OR
EARLY THURS MORNING.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR LHZ362-
     363-421-441>443-462>464.

     GALE WATCH FROM THURSDAY EVENING THROUGH LATE THURSDAY NIGHT FOR
     LHZ361.

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

$$

AVIATION.....KURIMSKI
SHORT TERM...SC
LONG TERM....DRK/SS
MARINE.......SC


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




000
FXUS63 KDTX 290458
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1158 PM EST WED JAN 28 2015


.AVIATION...

AN APPROACHING LOW WILL BRING PROGRESSIVELY LOWER CEILINGS AS IT
APPROACHES THE CENTRAL GREAT LAKES DURING THE EARLY MORNING HOURS.
THIS LOW LEVEL SYSTEM WILL BRING A MIX OF RAIN/SLEET/SNOW TO THE
REGION STARTING ROUGHLY AROUND 12Z. AN EARLIER ARRIVAL OF THE
FORCING AND A COLDER THERMAL PROFILE SUGGESTS ALL SNOW AT
MBS...STARTING AROUND OR SHORTLY AFTER 09Z. COLD AIR WRAPPING IN
BEHIND THE DEPARTING LOW WILL CHANGE THE MIXED PRECIPITATION BACK
OVER TO ALL SNOW DURING THE AFTERNOON HOURS BEFORE WINDING DOWN
DURING THURSDAY EVENING. AN INCH OR TWO OF SNOW IS POSSIBLE AT FNT
AND MBS...WITH LESS THAN AN INCH FROM PTK SOUTH TO THE METRO
AIRPORTS. VERY GUSTY NORTHWEST WINDS OF 25 TO 30 KNOTS ARE EXPECTED
BEHIND THE LOW LATE THIS AFTERNOON AND INTO THURSDAY EVENING AS THE
COLD AIR RUSHES SOUTHWARD.

FOR DTW...CONSIDERING THE DEGREE OF WARM AIR ALOFT FORECAST TO
OVERSPREAD METRO DETROIT...PRECIP IS EXPECTED TO START MAINLY AS
FREEZING RAIN. IT SHOULD TRANSITION OVER TO PURE RAIN DURING THE
COURSE OF THE MORNING AS SFC TEMPS WARM ABOVE FREEZING.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT AFTER 10Z.

* MEDIUM IN PRECIP TYPE STARTING AS A FZRA/IP MIX THIS MORNING.

&&

.PREV DISCUSSION...ISSUED 353 PM EST WED JAN 28 2015

SHORT TERM...THIS EVENING

A DEPARTING LOW LEVEL ANTICYCLONE HAS MAINTAINED AMPLE LOW LEVEL DRY
AIR ACROSS SE MI TODAY. LIGHT S-SE RETURN FLOW HAS IN TURN ALLOWED
TEMPS TO RISE INTO THE UPPER 20S/LOW 30S. HIGH CLOUDS WILL BE ON THE
INCREASE DURING THE REST OF THE AFTERNOON...FOLLOWED BY INCREASING
MID LEVEL CLOUDS THIS EVENING. THIS WILL OCCUR AS THE BROAD RIBBON
OF WARM AIR ADVECTION/MID LEVEL MOISTURE TRANSPORT NOW EXPANDING
ACROSS THE WRN GREAT LAKES CONTINUES TO ADVANCE TO THE EAST. THERE
SHOULD BE JUST ENOUGH DECOUPLING IN THE BOUNDARY LAYER TO SUPPORT
SOME DEGREE OF TEMP DROP THIS EVENING. STRENGTHENING LOW LEVEL
SOUTHERLY FLOW AHEAD OF A SFC LOW WILL DRIVE WARMER AIR IN DURING
THE NIGHT. THIS ALONG WITH INCREASING CLOUDS WILL LEAD TO A SLOW
WARMING TREND AFTER MIDNIGHT.

LONG TERM...LATE TONIGHT THROUGH NEXT WEDNESDAY

THE BEST SHOT AT PRECIP IN THE COMING WEEK ARRIVES RIGHT AWAY ON
THURSDAY AS A PAIR OF WAVES ATTEMPTS TO PHASE OVER THE REGION. LOW
AMPLITUDE LONG WAVE PATTERN ACROSS THE WEST/CENTRAL CONUS WILL
TRANSITION TO DEEP TROUGHING OVER THE EASTERN CONUS. THIS WILL OCCUR
AS ENERGY RELEASED FROM THE ALASKAN BAY LOW SURGES DOWN INTO THE
MIDWEST. A CURRENT SOUTHERN STREAM WAVE AND RESULTANT SFC LOW OVER
THE CENTRAL PLAINS WILL TRACK EASTERLY THE SOUTHERN GREAT LAKES
THURSDAY...LOOKING TO STAY JUST AHEAD OF THE FIRST NOTABLE NORTHERN
STREAM WAVE. THIS INTERACTION IS KEY TO HOW THE SYSTEM WILL PLAY OUT
FOR SE MI. THE SLOWER THE NORTHERN STREAM WAVE IS...THE MORE LIKELY
THE SOUTHERN STREAM WAVE WILL REMAIN IN TACK...VS A FASTER WAVE
CATCHING UP AND PHASING DIRECTLY OVERHEAD. THIS WOULD DISRUPT THE
LOW...SHEARING IT NORTH/SOUTH THROUGH THE REGION AS IT TRIES TO
REDEVELOP FURTHER DOWNSTREAM. IN THE END...MODEL SUITE HAS TRENDED
TOWARD KEEPING SOME SEPARATION BETWEEN THE SYSTEMS...THUS HAVE
ADJUSTED THE FORECAST ACCORDINGLY. THE DETAILS TO FOLLOW...

WITH THE CENTRAL PLAINS SFC LOW BEING LESS AFFECTED BY THE INCOMING
WAVE/JET MAX INTO SOUTHERN MI...THE LOW WILL BE ABLE TO MAINTAIN
MORE OF ITS STRUCTURE/FORCING. THIS IS ALREADY BEING SHOWN IN THE
MODELS BY KEEPING THE STRONG BAND OF ISENTROPIC ASCENT IN TACK AS IT
LIFTS THROUGH SW/CENTRAL MI EARLY THURSDAY MORNING AND THE
DEFORMATION BAND AS IT SWINGS THROUGH THURSDAY AFTERNOON. IT ALSO
KEEPS BRINGS THE NOSE OF A THETA E PLUME UP THROUGH THE AREA BETWEEN
12-18Z WITH A DECENT GRADIENT ON THE LEAD EDGE. A DEEP LAYER OF DRY
AIR FROM THE SFC TO 700MB IN PLACE WEDNESDAY NIGHT WILL HOLD BACK
MUCH OF THE PRECIP TIL AFTER 12Z MONDAY...AT LEAST FOR LOCATIONS
EAST OF I75. THE LEAD ISENTROPIC LIFT ON THE NE SIDE OF THE LOW WILL
LIFT THROUGH THE SAGINAW BAY FROM ABOUT 09-12Z. THIS WILL GIVE THAT
AREA AROUND A HALF INCH OF SNOWFALL FOR THE MORNING COMMUTE WHILE
BEGINNING TO SATURATE THE LOW LEVELS ACROSS THE REST OF THE REGION.
AFTER 12Z...STRONG SW FLOW IN THE LOW LEVELS PROMOTES GOOD WAA IN
THE 900-800MB LAYER WITH TEMPS GOING NEARLY ISOTHERMAL IN THE LAYER
RIGHT AROUND 0C. MODELS VARY A DEGREE OR TWO WITH THE LL THERMAL
PROFILE IN THE 12-18Z TIMEFRAME. THIS LEADS TO A COMPLICATED MIXED
PRECIP SCENARIO OVER SOUTHERN MI INTO THE EARLY AFTERNOON. THE MIXED
PRECIP WILL END LATER IN THE AFTERNOON OR EARLY EVENING AS STRONG
CAA SURGES IN FROM THE NW BEHIND THE NORTHERN STREAM TROUGH. THIS
WILL TURN THE REMAINING PRECIP...MAINLY IN THE DEFORMATION
BAND...INTO ALL SNOW FOR THE TAIL END OF THE EVENT. LOOKING FOR A
POSSIBLE INCH OVER THE THUMB AS THE BAND SWEEPS THROUGH WITH LESS
THAN A HALF INCH FURTHER SOUTH NEAR DETROIT. MODELS ARE PRETTY WELL
IN LINE WITH QPF FOR THE EVENT...WHICH HAS NOT CHANGED MUCH OVER THE
LAST FEW MODEL RUNS...MAINTAINING AROUND 0.25 INCHES ACROSS THE
NORTH AND AROUND 0.15-0.20 INCHES ACROSS THE SOUTH. THE WARM AIR
ALOFT WILL REALLY CUT INTO SNOWFALL TOTALS ACROSS THE
AREA...ESPECIALLY SOUTH OF M59 WHERE A MIX OF FREEZING RAIN AND
SLEET WILL LIKELY OCCUR FOR SEVERAL HOURS BEFORE CAA COOLS THE
ENVIRONMENT ENOUGH FOR SNOW. NOT EXPECTING MUCH IN THE WAY OF ICE
ACCUMULATION AS THIS AREA WILL WARM INTO THE MID 30S WITH RAIN
POSSIBLE BY AFTERNOON. LOCATIONS BETWEEN I69 AND M59 WILL LIKELY SEE
MORE OF A SNOW/SLEET MIX RESULTING IN MINOR ACCUMULATIONS OF 1-2
INCHES. NORTH OF I69 STANDS THE BEST CHANCE TO SEE A PURE SNOW
EVENT...BUT WITH LOW SNOWFALL RATIOS WILL LIKELY ONLY AMOUNT TO 2-3
INCHES.

ONCE THE PRECIP ENDS THURSDAY NIGHT...A SECOND COLD FRONT WILL SWEEP
THROUGH DOWN THROUGH MI DROPPING 850MB TEMPS TO 15C. EVEN WITH HIGH
PRESSURE AND A GOOD DEAL OF SUNSHINE FRIDAY AFTERNOON...HIGH
TEMPERATURES WILL LIKELY ONLY RISE INTO THE TEENS. LOWS FRIDAY NIGHT
WILL DIP BACK INTO THE SINGLE DIGITS.

AS FAR AS THIS WEEKEND...MODELS ARE AGAIN JUMPING BACK AND FORTH ON
THE TRACK FOR THE SUNDAY SYSTEM.  LATEST MODEL RUNS ARE INDICATING A
WEAKER AND MORE SOUTHERN TRACK WITH THE MAIN JET ENERGY AND
SHORTWAVE ASSOCIATED WITH THIS SYSTEM STAYING TO THE SOUTH OF THE
AREA.  SEEING THE MODEL SOLUTIONS VARYING...HAVE GONE WITH CHANCE
POPS UNTIL MODELS COME TO INTO BETTER CONSENSUS.  AT THIS
POINT...THE BETTER LOCATIONS FOR SEEING ANY SNOW WOULD LIKELY BE
AREAS CLOSER TO THE OHIO BORDER.  COLDER TEMPS WILL HANG AROUND AS
THE GREAT LAKES REGION REMAINS IN THE LONGWAVE TROUGH THROUGH THE
REMAINDER OF THE EXTENDED.

MARINE...

SOUTH-SOUTHEASTERLY WINDS WILL BE ON THE INCREASE TONIGHT AS LOW
PRESSURE APPROACHES FROM THE WEST. THE RESULTING WARM AIR ADVECTION
WILL INHIBIT THE DEGREE OF MIXING OVER THE LAKES. SO ALTHOUGH MODEL
SOLUTIONS SUGGEST GALE FORCE WINDS DOWN TO 1K FT...THE SHALLOW
STABLE LAYER OVER THE LAKES WILL INHIBIT THE POTENTIAL FOR GALE
FORCE WIND GUSTS TO OCCUR OVER A PERIOD GREATER THAN THREE HOURS.
THIS SUGGESTS THAT A GALE WARNING FOR TONIGHT WILL NOT BE NEEDED.
ALTHOUGH FREQUENT GUSTS TO 30 KNOTS ARE EXPECTED...MAINLY LATE
TONIGHT THROUGH THURS MORNING. WINDS WILL DECREASE THURS AFTERNOON
AS THE SURFACE LOW TRACKS OVERHEAD AND THEN VEER TO THE WEST-
NORTHWEST LATE THURS AS THE LOW HEADS EAST OF LAKE HURON. ARCTIC AIR
WILL THEN INFILTRATE THE REGION WITH THE DEPARTURE OF THE SFC LOW.
THIS WILL BOOST MIXING DEPTHS OVER THE LAKE AND WILL SUPPORT GALE
FORCE WINDS GUSTS THURS NIGHT INTO FRIDAY MORNING AND LAKE HURON
BEFORE THE GRADIENT WEAKENS SUBSTANTIALLY FRI AFTERNOON. THE GALE
WATCH WILL REMAIN IN PLACE FOR LAKE HURON WITH GROWING CONFIDENCE
THAT THIS WILL BE UPGRADED TO A GALE WARNING EITHER THIS EVENING OR
EARLY THURS MORNING.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR LHZ362-
     363-421-441>443-462>464.

     GALE WATCH FROM THURSDAY EVENING THROUGH LATE THURSDAY NIGHT FOR
     LHZ361.

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

$$

AVIATION.....KURIMSKI
SHORT TERM...SC
LONG TERM....DRK/SS
MARINE.......SC


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





000
FXUS63 KDTX 282321
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
621 PM EST WED JAN 28 2015


.AVIATION...

VERY DRY AIR IN THE LOW LEVELS ASSOCIATED WITH HIGH PRESSURE
DEPARTING TO THE EAST WILL MAINTAIN CLEAR SKIES BELOW 10K FT THROUGH
THE EVENING. STRENGTHENING SOUTHERLY FLOW AHEAD OF AN APPROACHING
SFC LOW RAISES SOME CONCERN FOR LOW LEVEL WIND SHEAR OVERNIGHT WITH
WINDS FORECAST TO INCREASE TO 45 KNOTS AT 2K FT. CURRENT INDICATIONS
ARE THAT THERE WILL BE ENOUGH MIXING NEAR THE SURFACE TO LEAD TO
MORE OF A LOW LEVEL TURBULENCE SITUATION /GUSTY SFC WINDS/ PRIMARILY
BETWEEN 08Z THROUGH DAYBREAK. THIS LOW LEVEL SYSTEM WILL BRING A MIX
OF RAIN/SLEET/SNOW TO THE REGION STARTING ROUGHLY AROUND 12Z ON
THURSDAY. AN EARLIER ARRIVAL OF THE FORCING AND A COLDER THERMAL
PROFILE SUGGESTS ALL SNOW AT MBS...STARTING AROUND OR SHORTLY AFTER
09Z.

FOR DTW...CONSIDERING THE DEGREE OF WARM AIR ALOFT FORECAST TO
OVERSPREAD METRO DETROIT...PRECIP IS EXPECTED TO START MAINLY AS
FREEZING RAIN. IT SHOULD TRANSITION OVER TO PURE RAIN DURING THE
COURSE OF THE MORNING AS SFC TEMPS WARM ABOVE FREEZING.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT AFTER 10Z.

* MEDIUM IN PRECIP TYPE STARTING AS A FZRA/IP MIX THURS MORNING.

&&

.PREV DISCUSSION...ISSUED 353 PM EST WED JAN 28 2015

SHORT TERM...THIS EVENING

A DEPARTING LOW LEVEL ANTICYCLONE HAS MAINTAINED AMPLE LOW LEVEL DRY
AIR ACROSS SE MI TODAY. LIGHT S-SE RETURN FLOW HAS IN TURN ALLOWED
TEMPS TO RISE INTO THE UPPER 20S/LOW 30S. HIGH CLOUDS WILL BE ON THE
INCREASE DURING THE REST OF THE AFTERNOON...FOLLOWED BY INCREASING
MID LEVEL CLOUDS THIS EVENING. THIS WILL OCCUR AS THE BROAD RIBBON
OF WARM AIR ADVECTION/MID LEVEL MOISTURE TRANSPORT NOW EXPANDING
ACROSS THE WRN GREAT LAKES CONTINUES TO ADVANCE TO THE EAST. THERE
SHOULD BE JUST ENOUGH DECOUPLING IN THE BOUNDARY LAYER TO SUPPORT
SOME DEGREE OF TEMP DROP THIS EVENING. STRENGTHENING LOW LEVEL
SOUTHERLY FLOW AHEAD OF A SFC LOW WILL DRIVE WARMER AIR IN DURING
THE NIGHT. THIS ALONG WITH INCREASING CLOUDS WILL LEAD TO A SLOW
WARMING TREND AFTER MIDNIGHT.

LONG TERM...LATE TONIGHT THROUGH NEXT WEDNESDAY

THE BEST SHOT AT PRECIP IN THE COMING WEEK ARRIVES RIGHT AWAY ON
THURSDAY AS A PAIR OF WAVES ATTEMPTS TO PHASE OVER THE REGION. LOW
AMPLITUDE LONG WAVE PATTERN ACROSS THE WEST/CENTRAL CONUS WILL
TRANSITION TO DEEP TROUGHING OVER THE EASTERN CONUS. THIS WILL OCCUR
AS ENERGY RELEASED FROM THE ALASKAN BAY LOW SURGES DOWN INTO THE
MIDWEST. A CURRENT SOUTHERN STREAM WAVE AND RESULTANT SFC LOW OVER
THE CENTRAL PLAINS WILL TRACK EASTERLY THE SOUTHERN GREAT LAKES
THURSDAY...LOOKING TO STAY JUST AHEAD OF THE FIRST NOTABLE NORTHERN
STREAM WAVE. THIS INTERACTION IS KEY TO HOW THE SYSTEM WILL PLAY OUT
FOR SE MI. THE SLOWER THE NORTHERN STREAM WAVE IS...THE MORE LIKELY
THE SOUTHERN STREAM WAVE WILL REMAIN IN TACK...VS A FASTER WAVE
CATCHING UP AND PHASING DIRECTLY OVERHEAD. THIS WOULD DISRUPT THE
LOW...SHEARING IT NORTH/SOUTH THROUGH THE REGION AS IT TRIES TO
REDEVELOP FURTHER DOWNSTREAM. IN THE END...MODEL SUITE HAS TRENDED
TOWARD KEEPING SOME SEPARATION BETWEEN THE SYSTEMS...THUS HAVE
ADJUSTED THE FORECAST ACCORDINGLY. THE DETAILS TO FOLLOW...

WITH THE CENTRAL PLAINS SFC LOW BEING LESS AFFECTED BY THE INCOMING
WAVE/JET MAX INTO SOUTHERN MI...THE LOW WILL BE ABLE TO MAINTAIN
MORE OF ITS STRUCTURE/FORCING. THIS IS ALREADY BEING SHOWN IN THE
MODELS BY KEEPING THE STRONG BAND OF ISENTROPIC ASCENT IN TACK AS IT
LIFTS THROUGH SW/CENTRAL MI EARLY THURSDAY MORNING AND THE
DEFORMATION BAND AS IT SWINGS THROUGH THURSDAY AFTERNOON. IT ALSO
KEEPS BRINGS THE NOSE OF A THETA E PLUME UP THROUGH THE AREA BETWEEN
12-18Z WITH A DECENT GRADIENT ON THE LEAD EDGE. A DEEP LAYER OF DRY
AIR FROM THE SFC TO 700MB IN PLACE WEDNESDAY NIGHT WILL HOLD BACK
MUCH OF THE PRECIP TIL AFTER 12Z MONDAY...AT LEAST FOR LOCATIONS
EAST OF I75. THE LEAD ISENTROPIC LIFT ON THE NE SIDE OF THE LOW WILL
LIFT THROUGH THE SAGINAW BAY FROM ABOUT 09-12Z. THIS WILL GIVE THAT
AREA AROUND A HALF INCH OF SNOWFALL FOR THE MORNING COMMUTE WHILE
BEGINNING TO SATURATE THE LOW LEVELS ACROSS THE REST OF THE REGION.
AFTER 12Z...STRONG SW FLOW IN THE LOW LEVELS PROMOTES GOOD WAA IN
THE 900-800MB LAYER WITH TEMPS GOING NEARLY ISOTHERMAL IN THE LAYER
RIGHT AROUND 0C. MODELS VARY A DEGREE OR TWO WITH THE LL THERMAL
PROFILE IN THE 12-18Z TIMEFRAME. THIS LEADS TO A COMPLICATED MIXED
PRECIP SCENARIO OVER SOUTHERN MI INTO THE EARLY AFTERNOON. THE MIXED
PRECIP WILL END LATER IN THE AFTERNOON OR EARLY EVENING AS STRONG
CAA SURGES IN FROM THE NW BEHIND THE NORTHERN STREAM TROUGH. THIS
WILL TURN THE REMAINING PRECIP...MAINLY IN THE DEFORMATION
BAND...INTO ALL SNOW FOR THE TAIL END OF THE EVENT. LOOKING FOR A
POSSIBLE INCH OVER THE THUMB AS THE BAND SWEEPS THROUGH WITH LESS
THAN A HALF INCH FURTHER SOUTH NEAR DETROIT. MODELS ARE PRETTY WELL
IN LINE WITH QPF FOR THE EVENT...WHICH HAS NOT CHANGED MUCH OVER THE
LAST FEW MODEL RUNS...MAINTAINING AROUND 0.25 INCHES ACROSS THE
NORTH AND AROUND 0.15-0.20 INCHES ACROSS THE SOUTH. THE WARM AIR
ALOFT WILL REALLY CUT INTO SNOWFALL TOTALS ACROSS THE
AREA...ESPECIALLY SOUTH OF M59 WHERE A MIX OF FREEZING RAIN AND
SLEET WILL LIKELY OCCUR FOR SEVERAL HOURS BEFORE CAA COOLS THE
ENVIRONMENT ENOUGH FOR SNOW. NOT EXPECTING MUCH IN THE WAY OF ICE
ACCUMULATION AS THIS AREA WILL WARM INTO THE MID 30S WITH RAIN
POSSIBLE BY AFTERNOON. LOCATIONS BETWEEN I69 AND M59 WILL LIKELY SEE
MORE OF A SNOW/SLEET MIX RESULTING IN MINOR ACCUMULATIONS OF 1-2
INCHES. NORTH OF I69 STANDS THE BEST CHANCE TO SEE A PURE SNOW
EVENT...BUT WITH LOW SNOWFALL RATIOS WILL LIKELY ONLY AMOUNT TO 2-3
INCHES.

ONCE THE PRECIP ENDS THURSDAY NIGHT...A SECOND COLD FRONT WILL SWEEP
THROUGH DOWN THROUGH MI DROPPING 850MB TEMPS TO 15C. EVEN WITH HIGH
PRESSURE AND A GOOD DEAL OF SUNSHINE FRIDAY AFTERNOON...HIGH
TEMPERATURES WILL LIKELY ONLY RISE INTO THE TEENS. LOWS FRIDAY NIGHT
WILL DIP BACK INTO THE SINGLE DIGITS.

AS FAR AS THIS WEEKEND...MODELS ARE AGAIN JUMPING BACK AND FORTH ON
THE TRACK FOR THE SUNDAY SYSTEM.  LATEST MODEL RUNS ARE INDICATING A
WEAKER AND MORE SOUTHERN TRACK WITH THE MAIN JET ENERGY AND
SHORTWAVE ASSOCIATED WITH THIS SYSTEM STAYING TO THE SOUTH OF THE
AREA.  SEEING THE MODEL SOLUTIONS VARYING...HAVE GONE WITH CHANCE
POPS UNTIL MODELS COME TO INTO BETTER CONSENSUS.  AT THIS
POINT...THE BETTER LOCATIONS FOR SEEING ANY SNOW WOULD LIKELY BE
AREAS CLOSER TO THE OHIO BORDER.  COLDER TEMPS WILL HANG AROUND AS
THE GREAT LAKES REGION REMAINS IN THE LONGWAVE TROUGH THROUGH THE
REMAINDER OF THE EXTENDED.

MARINE...

SOUTH-SOUTHEASTERLY WINDS WILL BE ON THE INCREASE TONIGHT AS LOW
PRESSURE APPROACHES FROM THE WEST. THE RESULTING WARM AIR ADVECTION
WILL INHIBIT THE DEGREE OF MIXING OVER THE LAKES. SO ALTHOUGH MODEL
SOLUTIONS SUGGEST GALE FORCE WINDS DOWN TO 1K FT...THE SHALLOW
STABLE LAYER OVER THE LAKES WILL INHIBIT THE POTENTIAL FOR GALE
FORCE WIND GUSTS TO OCCUR OVER A PERIOD GREATER THAN THREE HOURS.
THIS SUGGESTS THAT A GALE WARNING FOR TONIGHT WILL NOT BE NEEDED.
ALTHOUGH FREQUENT GUSTS TO 30 KNOTS ARE EXPECTED...MAINLY LATE
TONIGHT THROUGH THURS MORNING. WINDS WILL DECREASE THURS AFTERNOON
AS THE SURFACE LOW TRACKS OVERHEAD AND THEN VEER TO THE WEST-
NORTHWEST LATE THURS AS THE LOW HEADS EAST OF LAKE HURON. ARCTIC AIR
WILL THEN INFILTRATE THE REGION WITH THE DEPARTURE OF THE SFC LOW.
THIS WILL BOOST MIXING DEPTHS OVER THE LAKE AND WILL SUPPORT GALE
FORCE WINDS GUSTS THURS NIGHT INTO FRIDAY MORNING AND LAKE HURON
BEFORE THE GRADIENT WEAKENS SUBSTANTIALLY FRI AFTERNOON. THE GALE
WATCH WILL REMAIN IN PLACE FOR LAKE HURON WITH GROWING CONFIDENCE
THAT THIS WILL BE UPGRADED TO A GALE WARNING EITHER THIS EVENING OR
EARLY THURS MORNING.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR LHZ362-
     363-421-441>443-462>464.

     GALE WATCH FROM THURSDAY EVENING THROUGH LATE THURSDAY NIGHT FOR
     LHZ361.

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

$$

AVIATION.....KURIMSKI
SHORT TERM...SC
LONG TERM....DRK/SS
MARINE.......SC


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




000
FXUS63 KDTX 282321
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
621 PM EST WED JAN 28 2015


.AVIATION...

VERY DRY AIR IN THE LOW LEVELS ASSOCIATED WITH HIGH PRESSURE
DEPARTING TO THE EAST WILL MAINTAIN CLEAR SKIES BELOW 10K FT THROUGH
THE EVENING. STRENGTHENING SOUTHERLY FLOW AHEAD OF AN APPROACHING
SFC LOW RAISES SOME CONCERN FOR LOW LEVEL WIND SHEAR OVERNIGHT WITH
WINDS FORECAST TO INCREASE TO 45 KNOTS AT 2K FT. CURRENT INDICATIONS
ARE THAT THERE WILL BE ENOUGH MIXING NEAR THE SURFACE TO LEAD TO
MORE OF A LOW LEVEL TURBULENCE SITUATION /GUSTY SFC WINDS/ PRIMARILY
BETWEEN 08Z THROUGH DAYBREAK. THIS LOW LEVEL SYSTEM WILL BRING A MIX
OF RAIN/SLEET/SNOW TO THE REGION STARTING ROUGHLY AROUND 12Z ON
THURSDAY. AN EARLIER ARRIVAL OF THE FORCING AND A COLDER THERMAL
PROFILE SUGGESTS ALL SNOW AT MBS...STARTING AROUND OR SHORTLY AFTER
09Z.

FOR DTW...CONSIDERING THE DEGREE OF WARM AIR ALOFT FORECAST TO
OVERSPREAD METRO DETROIT...PRECIP IS EXPECTED TO START MAINLY AS
FREEZING RAIN. IT SHOULD TRANSITION OVER TO PURE RAIN DURING THE
COURSE OF THE MORNING AS SFC TEMPS WARM ABOVE FREEZING.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT AFTER 10Z.

* MEDIUM IN PRECIP TYPE STARTING AS A FZRA/IP MIX THURS MORNING.

&&

.PREV DISCUSSION...ISSUED 353 PM EST WED JAN 28 2015

SHORT TERM...THIS EVENING

A DEPARTING LOW LEVEL ANTICYCLONE HAS MAINTAINED AMPLE LOW LEVEL DRY
AIR ACROSS SE MI TODAY. LIGHT S-SE RETURN FLOW HAS IN TURN ALLOWED
TEMPS TO RISE INTO THE UPPER 20S/LOW 30S. HIGH CLOUDS WILL BE ON THE
INCREASE DURING THE REST OF THE AFTERNOON...FOLLOWED BY INCREASING
MID LEVEL CLOUDS THIS EVENING. THIS WILL OCCUR AS THE BROAD RIBBON
OF WARM AIR ADVECTION/MID LEVEL MOISTURE TRANSPORT NOW EXPANDING
ACROSS THE WRN GREAT LAKES CONTINUES TO ADVANCE TO THE EAST. THERE
SHOULD BE JUST ENOUGH DECOUPLING IN THE BOUNDARY LAYER TO SUPPORT
SOME DEGREE OF TEMP DROP THIS EVENING. STRENGTHENING LOW LEVEL
SOUTHERLY FLOW AHEAD OF A SFC LOW WILL DRIVE WARMER AIR IN DURING
THE NIGHT. THIS ALONG WITH INCREASING CLOUDS WILL LEAD TO A SLOW
WARMING TREND AFTER MIDNIGHT.

LONG TERM...LATE TONIGHT THROUGH NEXT WEDNESDAY

THE BEST SHOT AT PRECIP IN THE COMING WEEK ARRIVES RIGHT AWAY ON
THURSDAY AS A PAIR OF WAVES ATTEMPTS TO PHASE OVER THE REGION. LOW
AMPLITUDE LONG WAVE PATTERN ACROSS THE WEST/CENTRAL CONUS WILL
TRANSITION TO DEEP TROUGHING OVER THE EASTERN CONUS. THIS WILL OCCUR
AS ENERGY RELEASED FROM THE ALASKAN BAY LOW SURGES DOWN INTO THE
MIDWEST. A CURRENT SOUTHERN STREAM WAVE AND RESULTANT SFC LOW OVER
THE CENTRAL PLAINS WILL TRACK EASTERLY THE SOUTHERN GREAT LAKES
THURSDAY...LOOKING TO STAY JUST AHEAD OF THE FIRST NOTABLE NORTHERN
STREAM WAVE. THIS INTERACTION IS KEY TO HOW THE SYSTEM WILL PLAY OUT
FOR SE MI. THE SLOWER THE NORTHERN STREAM WAVE IS...THE MORE LIKELY
THE SOUTHERN STREAM WAVE WILL REMAIN IN TACK...VS A FASTER WAVE
CATCHING UP AND PHASING DIRECTLY OVERHEAD. THIS WOULD DISRUPT THE
LOW...SHEARING IT NORTH/SOUTH THROUGH THE REGION AS IT TRIES TO
REDEVELOP FURTHER DOWNSTREAM. IN THE END...MODEL SUITE HAS TRENDED
TOWARD KEEPING SOME SEPARATION BETWEEN THE SYSTEMS...THUS HAVE
ADJUSTED THE FORECAST ACCORDINGLY. THE DETAILS TO FOLLOW...

WITH THE CENTRAL PLAINS SFC LOW BEING LESS AFFECTED BY THE INCOMING
WAVE/JET MAX INTO SOUTHERN MI...THE LOW WILL BE ABLE TO MAINTAIN
MORE OF ITS STRUCTURE/FORCING. THIS IS ALREADY BEING SHOWN IN THE
MODELS BY KEEPING THE STRONG BAND OF ISENTROPIC ASCENT IN TACK AS IT
LIFTS THROUGH SW/CENTRAL MI EARLY THURSDAY MORNING AND THE
DEFORMATION BAND AS IT SWINGS THROUGH THURSDAY AFTERNOON. IT ALSO
KEEPS BRINGS THE NOSE OF A THETA E PLUME UP THROUGH THE AREA BETWEEN
12-18Z WITH A DECENT GRADIENT ON THE LEAD EDGE. A DEEP LAYER OF DRY
AIR FROM THE SFC TO 700MB IN PLACE WEDNESDAY NIGHT WILL HOLD BACK
MUCH OF THE PRECIP TIL AFTER 12Z MONDAY...AT LEAST FOR LOCATIONS
EAST OF I75. THE LEAD ISENTROPIC LIFT ON THE NE SIDE OF THE LOW WILL
LIFT THROUGH THE SAGINAW BAY FROM ABOUT 09-12Z. THIS WILL GIVE THAT
AREA AROUND A HALF INCH OF SNOWFALL FOR THE MORNING COMMUTE WHILE
BEGINNING TO SATURATE THE LOW LEVELS ACROSS THE REST OF THE REGION.
AFTER 12Z...STRONG SW FLOW IN THE LOW LEVELS PROMOTES GOOD WAA IN
THE 900-800MB LAYER WITH TEMPS GOING NEARLY ISOTHERMAL IN THE LAYER
RIGHT AROUND 0C. MODELS VARY A DEGREE OR TWO WITH THE LL THERMAL
PROFILE IN THE 12-18Z TIMEFRAME. THIS LEADS TO A COMPLICATED MIXED
PRECIP SCENARIO OVER SOUTHERN MI INTO THE EARLY AFTERNOON. THE MIXED
PRECIP WILL END LATER IN THE AFTERNOON OR EARLY EVENING AS STRONG
CAA SURGES IN FROM THE NW BEHIND THE NORTHERN STREAM TROUGH. THIS
WILL TURN THE REMAINING PRECIP...MAINLY IN THE DEFORMATION
BAND...INTO ALL SNOW FOR THE TAIL END OF THE EVENT. LOOKING FOR A
POSSIBLE INCH OVER THE THUMB AS THE BAND SWEEPS THROUGH WITH LESS
THAN A HALF INCH FURTHER SOUTH NEAR DETROIT. MODELS ARE PRETTY WELL
IN LINE WITH QPF FOR THE EVENT...WHICH HAS NOT CHANGED MUCH OVER THE
LAST FEW MODEL RUNS...MAINTAINING AROUND 0.25 INCHES ACROSS THE
NORTH AND AROUND 0.15-0.20 INCHES ACROSS THE SOUTH. THE WARM AIR
ALOFT WILL REALLY CUT INTO SNOWFALL TOTALS ACROSS THE
AREA...ESPECIALLY SOUTH OF M59 WHERE A MIX OF FREEZING RAIN AND
SLEET WILL LIKELY OCCUR FOR SEVERAL HOURS BEFORE CAA COOLS THE
ENVIRONMENT ENOUGH FOR SNOW. NOT EXPECTING MUCH IN THE WAY OF ICE
ACCUMULATION AS THIS AREA WILL WARM INTO THE MID 30S WITH RAIN
POSSIBLE BY AFTERNOON. LOCATIONS BETWEEN I69 AND M59 WILL LIKELY SEE
MORE OF A SNOW/SLEET MIX RESULTING IN MINOR ACCUMULATIONS OF 1-2
INCHES. NORTH OF I69 STANDS THE BEST CHANCE TO SEE A PURE SNOW
EVENT...BUT WITH LOW SNOWFALL RATIOS WILL LIKELY ONLY AMOUNT TO 2-3
INCHES.

ONCE THE PRECIP ENDS THURSDAY NIGHT...A SECOND COLD FRONT WILL SWEEP
THROUGH DOWN THROUGH MI DROPPING 850MB TEMPS TO 15C. EVEN WITH HIGH
PRESSURE AND A GOOD DEAL OF SUNSHINE FRIDAY AFTERNOON...HIGH
TEMPERATURES WILL LIKELY ONLY RISE INTO THE TEENS. LOWS FRIDAY NIGHT
WILL DIP BACK INTO THE SINGLE DIGITS.

AS FAR AS THIS WEEKEND...MODELS ARE AGAIN JUMPING BACK AND FORTH ON
THE TRACK FOR THE SUNDAY SYSTEM.  LATEST MODEL RUNS ARE INDICATING A
WEAKER AND MORE SOUTHERN TRACK WITH THE MAIN JET ENERGY AND
SHORTWAVE ASSOCIATED WITH THIS SYSTEM STAYING TO THE SOUTH OF THE
AREA.  SEEING THE MODEL SOLUTIONS VARYING...HAVE GONE WITH CHANCE
POPS UNTIL MODELS COME TO INTO BETTER CONSENSUS.  AT THIS
POINT...THE BETTER LOCATIONS FOR SEEING ANY SNOW WOULD LIKELY BE
AREAS CLOSER TO THE OHIO BORDER.  COLDER TEMPS WILL HANG AROUND AS
THE GREAT LAKES REGION REMAINS IN THE LONGWAVE TROUGH THROUGH THE
REMAINDER OF THE EXTENDED.

MARINE...

SOUTH-SOUTHEASTERLY WINDS WILL BE ON THE INCREASE TONIGHT AS LOW
PRESSURE APPROACHES FROM THE WEST. THE RESULTING WARM AIR ADVECTION
WILL INHIBIT THE DEGREE OF MIXING OVER THE LAKES. SO ALTHOUGH MODEL
SOLUTIONS SUGGEST GALE FORCE WINDS DOWN TO 1K FT...THE SHALLOW
STABLE LAYER OVER THE LAKES WILL INHIBIT THE POTENTIAL FOR GALE
FORCE WIND GUSTS TO OCCUR OVER A PERIOD GREATER THAN THREE HOURS.
THIS SUGGESTS THAT A GALE WARNING FOR TONIGHT WILL NOT BE NEEDED.
ALTHOUGH FREQUENT GUSTS TO 30 KNOTS ARE EXPECTED...MAINLY LATE
TONIGHT THROUGH THURS MORNING. WINDS WILL DECREASE THURS AFTERNOON
AS THE SURFACE LOW TRACKS OVERHEAD AND THEN VEER TO THE WEST-
NORTHWEST LATE THURS AS THE LOW HEADS EAST OF LAKE HURON. ARCTIC AIR
WILL THEN INFILTRATE THE REGION WITH THE DEPARTURE OF THE SFC LOW.
THIS WILL BOOST MIXING DEPTHS OVER THE LAKE AND WILL SUPPORT GALE
FORCE WINDS GUSTS THURS NIGHT INTO FRIDAY MORNING AND LAKE HURON
BEFORE THE GRADIENT WEAKENS SUBSTANTIALLY FRI AFTERNOON. THE GALE
WATCH WILL REMAIN IN PLACE FOR LAKE HURON WITH GROWING CONFIDENCE
THAT THIS WILL BE UPGRADED TO A GALE WARNING EITHER THIS EVENING OR
EARLY THURS MORNING.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR LHZ362-
     363-421-441>443-462>464.

     GALE WATCH FROM THURSDAY EVENING THROUGH LATE THURSDAY NIGHT FOR
     LHZ361.

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

$$

AVIATION.....KURIMSKI
SHORT TERM...SC
LONG TERM....DRK/SS
MARINE.......SC


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





000
FXUS63 KDTX 282053
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
353 PM EST WED JAN 28 2015

.SHORT TERM...THIS EVENING

A DEPARTING LOW LEVEL ANTICYCLONE HAS MAINTAINED AMPLE LOW LEVEL DRY
AIR ACROSS SE MI TODAY. LIGHT S-SE RETURN FLOW HAS IN TURN ALLOWED
TEMPS TO RISE INTO THE UPPER 20S/LOW 30S. HIGH CLOUDS WILL BE ON THE
INCREASE DURING THE REST OF THE AFTERNOON...FOLLOWED BY INCREASING
MID LEVEL CLOUDS THIS EVENING. THIS WILL OCCUR AS THE BROAD RIBBON
OF WARM AIR ADVECTION/MID LEVEL MOISTURE TRANSPORT NOW EXPANDING
ACROSS THE WRN GREAT LAKES CONTINUES TO ADVANCE TO THE EAST. THERE
SHOULD BE JUST ENOUGH DECOUPLING IN THE BOUNDARY LAYER TO SUPPORT
SOME DEGREE OF TEMP DROP THIS EVENING. STRENGTHENING LOW LEVEL
SOUTHERLY FLOW AHEAD OF A SFC LOW WILL DRIVE WARMER AIR IN DURING
THE NIGHT. THIS ALONG WITH INCREASING CLOUDS WILL LEAD TO A SLOW
WARMING TREND AFTER MIDNIGHT.

&&

.LONG TERM...LATE TONIGHT THROUGH NEXT WEDNESDAY

THE BEST SHOT AT PRECIP IN THE COMING WEEK ARRIVES RIGHT AWAY ON
THURSDAY AS A PAIR OF WAVES ATTEMPTS TO PHASE OVER THE REGION. LOW
AMPLITUDE LONG WAVE PATTERN ACROSS THE WEST/CENTRAL CONUS WILL
TRANSITION TO DEEP TROUGHING OVER THE EASTERN CONUS. THIS WILL OCCUR
AS ENERGY RELEASED FROM THE ALASKAN BAY LOW SURGES DOWN INTO THE
MIDWEST. A CURRENT SOUTHERN STREAM WAVE AND RESULTANT SFC LOW OVER
THE CENTRAL PLAINS WILL TRACK EASTERLY THE SOUTHERN GREAT LAKES
THURSDAY...LOOKING TO STAY JUST AHEAD OF THE FIRST NOTABLE NORTHERN
STREAM WAVE. THIS INTERACTION IS KEY TO HOW THE SYSTEM WILL PLAY OUT
FOR SE MI. THE SLOWER THE NORTHERN STREAM WAVE IS...THE MORE LIKELY
THE SOUTHERN STREAM WAVE WILL REMAIN IN TACK...VS A FASTER WAVE
CATCHING UP AND PHASING DIRECTLY OVERHEAD. THIS WOULD DISRUPT THE
LOW...SHEARING IT NORTH/SOUTH THROUGH THE REGION AS IT TRIES TO
REDEVELOP FURTHER DOWNSTREAM. IN THE END...MODEL SUITE HAS TRENDED
TOWARD KEEPING SOME SEPARATION BETWEEN THE SYSTEMS...THUS HAVE
ADJUSTED THE FORECAST ACCORDINGLY. THE DETAILS TO FOLLOW...

WITH THE CENTRAL PLAINS SFC LOW BEING LESS AFFECTED BY THE INCOMING
WAVE/JET MAX INTO SOUTHERN MI...THE LOW WILL BE ABLE TO MAINTAIN
MORE OF ITS STRUCTURE/FORCING. THIS IS ALREADY BEING SHOWN IN THE
MODELS BY KEEPING THE STRONG BAND OF ISENTROPIC ASCENT IN TACK AS IT
LIFTS THROUGH SW/CENTRAL MI EARLY THURSDAY MORNING AND THE
DEFORMATION BAND AS IT SWINGS THROUGH THURSDAY AFTERNOON. IT ALSO
KEEPS BRINGS THE NOSE OF A THETA E PLUME UP THROUGH THE AREA BETWEEN
12-18Z WITH A DECENT GRADIENT ON THE LEAD EDGE. A DEEP LAYER OF DRY
AIR FROM THE SFC TO 700MB IN PLACE WEDNESDAY NIGHT WILL HOLD BACK
MUCH OF THE PRECIP TIL AFTER 12Z MONDAY...AT LEAST FOR LOCATIONS
EAST OF I75. THE LEAD ISENTROPIC LIFT ON THE NE SIDE OF THE LOW WILL
LIFT THROUGH THE SAGINAW BAY FROM ABOUT 09-12Z. THIS WILL GIVE THAT
AREA AROUND A HALF INCH OF SNOWFALL FOR THE MORNING COMMUTE WHILE
BEGINNING TO SATURATE THE LOW LEVELS ACROSS THE REST OF THE REGION.
AFTER 12Z...STRONG SW FLOW IN THE LOW LEVELS PROMOTES GOOD WAA IN
THE 900-800MB LAYER WITH TEMPS GOING NEARLY ISOTHERMAL IN THE LAYER
RIGHT AROUND 0C. MODELS VARY A DEGREE OR TWO WITH THE LL THERMAL
PROFILE IN THE 12-18Z TIMEFRAME. THIS LEADS TO A COMPLICATED MIXED
PRECIP SCENARIO OVER SOUTHERN MI INTO THE EARLY AFTERNOON. THE MIXED
PRECIP WILL END LATER IN THE AFTERNOON OR EARLY EVENING AS STRONG
CAA SURGES IN FROM THE NW BEHIND THE NORTHERN STREAM TROUGH. THIS
WILL TURN THE REMAINING PRECIP...MAINLY IN THE DEFORMATION
BAND...INTO ALL SNOW FOR THE TAIL END OF THE EVENT. LOOKING FOR A
POSSIBLE INCH OVER THE THUMB AS THE BAND SWEEPS THROUGH WITH LESS
THAN A HALF INCH FURTHER SOUTH NEAR DETROIT. MODELS ARE PRETTY WELL
IN LINE WITH QPF FOR THE EVENT...WHICH HAS NOT CHANGED MUCH OVER THE
LAST FEW MODEL RUNS...MAINTAINING AROUND 0.25 INCHES ACROSS THE
NORTH AND AROUND 0.15-0.20 INCHES ACROSS THE SOUTH. THE WARM AIR
ALOFT WILL REALLY CUT INTO SNOWFALL TOTALS ACROSS THE
AREA...ESPECIALLY SOUTH OF M59 WHERE A MIX OF FREEZING RAIN AND
SLEET WILL LIKELY OCCUR FOR SEVERAL HOURS BEFORE CAA COOLS THE
ENVIRONMENT ENOUGH FOR SNOW. NOT EXPECTING MUCH IN THE WAY OF ICE
ACCUMULATION AS THIS AREA WILL WARM INTO THE MID 30S WITH RAIN
POSSIBLE BY AFTERNOON. LOCATIONS BETWEEN I69 AND M59 WILL LIKELY SEE
MORE OF A SNOW/SLEET MIX RESULTING IN MINOR ACCUMULATIONS OF 1-2
INCHES. NORTH OF I69 STANDS THE BEST CHANCE TO SEE A PURE SNOW
EVENT...BUT WITH LOW SNOWFALL RATIOS WILL LIKELY ONLY AMOUNT TO 2-3
INCHES.

ONCE THE PRECIP ENDS THURSDAY NIGHT...A SECOND COLD FRONT WILL SWEEP
THROUGH DOWN THROUGH MI DROPPING 850MB TEMPS TO 15C. EVEN WITH HIGH
PRESSURE AND A GOOD DEAL OF SUNSHINE FRIDAY AFTERNOON...HIGH
TEMPERATURES WILL LIKELY ONLY RISE INTO THE TEENS. LOWS FRIDAY NIGHT
WILL DIP BACK INTO THE SINGLE DIGITS.

AS FAR AS THIS WEEKEND...MODELS ARE AGAIN JUMPING BACK AND FORTH ON
THE TRACK FOR THE SUNDAY SYSTEM.  LATEST MODEL RUNS ARE INDICATING A
WEAKER AND MORE SOUTHERN TRACK WITH THE MAIN JET ENERGY AND
SHORTWAVE ASSOCIATED WITH THIS SYSTEM STAYING TO THE SOUTH OF THE
AREA.  SEEING THE MODEL SOLUTIONS VARYING...HAVE GONE WITH CHANCE
POPS UNTIL MODELS COME TO INTO BETTER CONSENSUS.  AT THIS
POINT...THE BETTER LOCATIONS FOR SEEING ANY SNOW WOULD LIKELY BE
AREAS CLOSER TO THE OHIO BORDER.  COLDER TEMPS WILL HANG AROUND AS
THE GREAT LAKES REGION REMAINS IN THE LONGWAVE TROUGH THROUGH THE
REMAINDER OF THE EXTENDED.

&&

.MARINE...

SOUTH-SOUTHEASTERLY WINDS WILL BE ON THE INCREASE TONIGHT AS LOW
PRESSURE APPROACHES FROM THE WEST. THE RESULTING WARM AIR ADVECTION
WILL INHIBIT THE DEGREE OF MIXING OVER THE LAKES. SO ALTHOUGH MODEL
SOLUTIONS SUGGEST GALE FORCE WINDS DOWN TO 1K FT...THE SHALLOW
STABLE LAYER OVER THE LAKES WILL INHIBIT THE POTENTIAL FOR GALE
FORCE WIND GUSTS TO OCCUR OVER A PERIOD GREATER THAN THREE HOURS.
THIS SUGGESTS THAT A GALE WARNING FOR TONIGHT WILL NOT BE NEEDED.
ALTHOUGH FREQUENT GUSTS TO 30 KNOTS ARE EXPECTED...MAINLY LATE
TONIGHT THROUGH THURS MORNING. WINDS WILL DECREASE THURS AFTERNOON
AS THE SURFACE LOW TRACKS OVERHEAD AND THEN VEER TO THE WEST-
NORTHWEST LATE THURS AS THE LOW HEADS EAST OF LAKE HURON. ARCTIC AIR
WILL THEN INFILTRATE THE REGION WITH THE DEPARTURE OF THE SFC LOW.
THIS WILL BOOST MIXING DEPTHS OVER THE LAKE AND WILL SUPPORT GALE
FORCE WINDS GUSTS THURS NIGHT INTO FRIDAY MORNING AND LAKE HURON
BEFORE THE GRADIENT WEAKENS SUBSTANTIALLY FRI AFTERNOON. THE GALE
WATCH WILL REMAIN IN PLACE FOR LAKE HURON WITH GROWING CONFIDENCE
THAT THIS WILL BE UPGRADED TO A GALE WARNING EITHER THIS EVENING OR
EARLY THURS MORNING.

&&

.AVIATION...ISSUED 1202 PM EST WED JAN 28 2015

VERY DRY AIR IN THE LOW LEVELS ASSOCIATED WITH HIGH PRESSURE
DEPARTING TO THE EAST WILL MAINTAIN CLEAR SKIES BELOW 10K FT THROUGH
THE AFTERNOON AND EVENING. STRENGTHENING SOUTHERLY FLOW AHEAD OF AN
APPROACHING SFC LOW RAISES SOME CONCERN FOR LOW LEVEL WIND SHEAR
OVERNIGHT WITH WINDS FORECAST TO INCREASE TO 45 KNOTS AT 2K FT.
CURRENT INDICATIONS ARE THAT THERE WILL BE ENOUGH MIXING NEAR THE
SURFACE TO LEAD TO MORE OF A LOW LEVEL TURBULENCE SITUATION /GUSTY
SFC WINDS/ PRIMARILY BETWEEN 08Z THROUGH DAYBREAK. THIS LOW LEVEL
SYSTEM WILL BRING A MIX OF RAIN/SLEET/SNOW TO THE REGION STARTING
ROUGHLY AROUND 12Z. AN EARLIER ARRIVAL OF THE FORCING AND A COLDER
THERMAL PROFILE SUGGESTS ALL SNOW AT MBS...STARTING AROUND OR
SHORTLY AFTER 09Z.

FOR DTW...CONSIDERING THE DEGREE OF WARM AIR ALOFT FORECAST TO
OVERSPREAD METRO DETROIT...PRECIP IS EXPECTED TO START MAINLY AS
FREEZING RAIN. IT SHOULD TRANSITION OVER TO PURE RAIN DURING THE
COURSE OF THE MORNING AS SFC TEMPS WARM ABOVE FREEZING.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT AFTER 10Z.

* MEDIUM IN PRECIP TYPE STARTING AS A FZRA/IP MIX THURS MORNING.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR LHZ362-
     363-421-441>443-462>464.

     GALE WATCH FROM THURSDAY EVENING THROUGH LATE THURSDAY NIGHT FOR
     LHZ361.

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

$$

SHORT TERM...SC
LONG TERM....DRK/SS
MARINE.......SC
AVIATION.....SC


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




000
FXUS63 KDTX 281702
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1202 PM EST WED JAN 28 2015


.AVIATION...

VERY DRY AIR IN THE LOW LEVELS ASSOCIATED WITH HIGH PRESSURE
DEPARTING TO THE EAST WILL MAINTAIN CLEAR SKIES BELOW 10K FT THROUGH
THE AFTERNOON AND EVENING. STRENGTHENING SOUTHERLY FLOW AHEAD OF AN
APPROACHING SFC LOW RAISES SOME CONCERN FOR LOW LEVEL WIND SHEAR
OVERNIGHT WITH WINDS FORECAST TO INCREASE TO 45 KNOTS AT 2K FT.
CURRENT INDICATIONS ARE THAT THERE WILL BE ENOUGH MIXING NEAR THE
SURFACE TO LEAD TO MORE OF A LOW LEVEL TURBULENCE SITUATION /GUSTY
SFC WINDS/ PRIMARILY BETWEEN 08Z THROUGH DAYBREAK. THIS LOW LEVEL
SYSTEM WILL BRING A MIX OF RAIN/SLEET/SNOW TO THE REGION STARTING
ROUGHLY AROUND 12Z. AN EARLIER ARRIVAL OF THE FORCING AND A COLDER
THERMAL PROFILE SUGGESTS ALL SNOW AT MBS...STARTING AROUND OR
SHORTLY AFTER 09Z.

FOR DTW...CONSIDERING THE DEGREE OF WARM AIR ALOFT FORECAST TO
OVERSPREAD METRO DETROIT...PRECIP IS EXPECTED TO START MAINLY AS
FREEZING RAIN. IT SHOULD TRANSITION OVER TO PURE RAIN DURING THE
COURSE OF THE MORNING AS SFC TEMPS WARM ABOVE FREEZING.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT AFTER 10Z.

* MEDIUM IN PRECIP TYPE STARTING AS A FZRA/IP MIX THURS MORNING.

&&

.PREV DISCUSSION...ISSUED 309 AM EST WED JAN 28 2015

SHORT TERM...TODAY AND TONIGHT

AFTER A CHILLY START...TEMPERATURES WILL REBOUND TO NEAR 30 DEGREES
TODAY AS SOUTHERLY WINDS INCREASE IN ADVANCE OF AN APPROACHING WAVE
OF LOW PRESSURE. MOSTLY SUNNY SKIES WILL GIVE WAY TO INCREASING HIGH
CLOUDINESS AS THE LEADING EDGE OF MOISTURE ASSOCIATED WITH THE WAVE
OVERSPREADS THE AREA.

CLOUDS WILL THEN THICKEN AND LOWER GRADUALLY INTO TONIGHT AS THIS
SYSTEM MOVES INTO THE CENTRAL GREAT LAKES WITH LIGHT SNOW LIKELY
DEVELOPING LATE TONIGHT OVER PARTS OF THE AREA. ACCUMULATIONS WILL
BE MINIMAL PRIOR TO 12Z WITH JUST A FEW TENTHS OF AN INCH AT MOST.
TEMPERATURES...MEANWHILE...WILL REMAIN RELATIVELY MILD AS CLOUDS
INCREASE WITH LOWS HOLDING IN THE LOWER 20S.

LONG TERM...

UPPER JET WILL INTENSIFY OVER NORTHERN CANADA TODAY AS EAST PAC
RIDGING BUILDS TOWARD DIGGING HIGH-LATITUDE ENERGY OVER NORTHERN
ALASKA AND THE NW TERRITORIES AT 07Z THIS MORNING. THIS JET
ENHANCEMENT WILL HELP TO AMPLIFY A NORTHERN STREAM TROUGH THAT WILL
ABSORB THE SHORTWAVE OVER SOUTHERN ALBERTA/SASKATCHEWAN THIS MORNING
BY LATE TONIGHT INTO EARLY THURSDAY. THE DIGGING TROUGH WILL ALSO
STEER THE REMNANT BAJA ENERGY OVER WYOMING ACROSS THE OHIO VALLEY.

MERIDIONALLY ORIENTED SURFACE TROUGH WILL TRANSIT THE STATE ON
THURSDAY, ANCHORED ON BOTH ENDS BY WEAK LOW PRESSURE CENTERS TIED TO
NORTHERN & SOUTHERN FORCING MAXIMA ACCORDINGLY. AS NOTED IN THE
PREVIOUS FORECAST PACKAGE, IT IS REASONABLE TO RESPECT MODEL
SOLUTIONS LEANING TOWARD A STRONGER SOUTHERN WAVE GIVEN LIMITED
UPSTREAM STATIC STABILITY THAT WILL FAVOR STRONGER LARGE SCALE
ASCENT. THE 00Z GFS HAS, IN FACT, TRENDED IN THIS DIRECTION. THE
ECMWF HAS SHOWN LITTLE CHANGE AND DEPICTS A MORE OPEN SURFACE
CIRCULATION, BUT STILL STRONGER THAN THE REMAINING GUIDANCE. RESPECT
IS GIVEN TO THE 00Z GFS, BUT AS A 4+MB OUTLIER AT THIS RATHER SHORT
LEAD TIME, DECIDED AGAINST A FULL BUY-IN.

EXPECTATIONS FOR GENERAL EVOLUTION REMAIN LARGELY UNCHANGED
REGARDLESS. LOW-LEVEL JET RESPONSE WILL DEVELOP OVER THE MIDDLE
MISSISSIPPI VALLEY WITHIN BROADER SOUTHERLY FLOW REGIME TODAY BEFORE
PROGRESSING EAST ACROSS THE AREA 6-12Z TONIGHT. WARMING OF THE MID-
LEVELS WILL BRING BRIEF BUT WELL-DEFINED WINDOW FOR FREEZING RAIN
ACROSS SOUTHERN AREAS DURING THE MORNING. ONGOING SURFACE WARM
ADVECTION AND DIURNAL HEATING WILL JEOPARDIZE SNOW CHANCES SOUTH OF
AT LEAST I-94 FOR THE NEXT SEVERAL HOURS WHERE MIDDAY CONDITIONS
WILL BE STRONGLY DEPENDENT ON THE STRENGTH OF THE SURFACE LOW. NORTH
OF I-69, WEAK DEFORMATION AND MORE FAVORABLE THERMODYNAMIC PROFILES
SHOULD HELP TRANSLATE 0.25" QPF INTO 2-3" OF SNOW ACCUMULATION. IN
BETWEEN, MAINLY SNOW IS EXPECTED BETWEEN ROUGHLY I-696/M59, ALTHOUGH
A DEEP LAYER OF TEMPERATURES DECIDEDLY WARMER THAN -10C THROUGH THE
LOWEST 10KFT WILL SIGNIFICANTLY REDUCE SNOW RATIOS. HERE,
ACCUMULATIONS ARE FORECAST TO RANGE FROM 0.5 TO 1.5". THE BEST SHOT
OF ACCUMULATING SNOW FOR THE SOUTHERN 2/3 OF THE AREA WILL MOST
LIKELY BE IMMEDIATELY IN THE WAKE OF THE SURFACE COLD FRONT AFTER
20Z, WHEN COOLING THERMAL PROFILES WILL SUPPORT BETTER DENDRITE
PRODUCTION PRIOR TO THE EXIT OF THE DEEPER MOISTURE.

DIGGING HIGH-LATITUDE ENERGY WILL PUSH A STRONG COLD FRONT THROUGH
THE AREA FROM NW TO SE THURSDAY NIGHT. THIS SHOT OF COLD ADVECTION
WILL DROP 925MB TEMPERATURES FROM A PEAK OF NEAR 0C DURING THURS
AFTERNOON TO -17C FRIDAY MORNING. NORTHWEST FETCH SHOULD DEFLECT ANY
LAKE EFFECT TO THE SOUTHWEST, BUT BOTH LAKE CLOUDS AND LES LOOK TO
BE HARD TO COME BY GIVEN MODEL DEPICTIONS OF RAPIDLY BUILDING HIGH
PRESSURE THURSDAY NIGHT. HIGHS FRIDAY WILL BE LIMITED TO THE
MID/UPPER TEENS IN MOST SPOTS DESPITE PROSPECTS FOR MOSTLY SUNNY
SKIES. QUICK REBOUND OF THE HEIGHT FIELD DOWNSTREAM OF PAC ENERGY
STREAMING INTO THE WESTERN U.S. WILL HELP TEMPS RECOVER INTO THE MID
20S ON SATURDAY.

FINALLY, MODEL CONSENSUS IS INCREASING THAT A WIDE SWATH OF
ACCUMULATING SNOW WILL DEVELOP OVER THE OHIO VALLEY AND GREAT LAKES
SATURDAY NIGHT INTO SUNDAY NIGHT. THIS WILL OCCUR AS A NORTHERN WAVE
DIGS INTO THE WESTERN PLAINS AND ENTRAINS A HIGHLY UNCERTAIN
PERCENTAGE OF ENERGY FROM A CLOSED LOW OVER THE 4 CORNERS. BROAD
REGION OF NORTHWARD MOISTURE TRANSPORT AND STRONG LARGE SCALE RIGHT
ENTRANCE JET SUPPORT FAVOR RETAINING THE ENTRY-LEVEL LIKELY POPS
INTRODUCED BY THE BLENDED EXTENDED GRIDS.

MARINE...

FRESH TO STRONG SOUTHERLY WINDS WILL DEVELOP LATE TONIGHT INTO
THURSDAY MORNING AS A WEAK LOW PRESSURE SYSTEM TRAVERSES THE GREAT
LAKES. STABLE SOUTHERLY FLOW REGIME WILL LIMIT THE POTENTIAL FOR
WIND GUSTS. THEREFORE...WHILE AN ISOLATED GUST TO GALE FORCE IS
POSSIBLE OVER LAKE HURON...COVERAGE AND DURATION WILL MEET GALE
CRITERIA. A STRONG COLD FRONT WILL THEN SURGE ACROSS THE WATERS ON
THURSDAY NIGHT. MUCH COLDER NORTHWEST FLOW WILL SUPPORT WIDESPREAD
GUSTS TO STRONG GALES ACROSS ALL OF LAKE HURON INCLUDING THE
NEARSHORE WATERS. SIGNIFICANT WAVE HEIGHTS WILL EXCEED 12 FEET OVER
THE SOUTHERN HALF OF LAKE HURON BY LATE THURSDAY NIGHT. WINDS AND
WAVES WILL SUBSIDE FRIDAY INTO FRIDAY NIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR
     LHZ361>363-421-441>443-462>464.

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

$$

AVIATION.....SC
SHORT TERM...DG
LONG TERM....JVC
MARINE.......JVC


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





000
FXUS63 KDTX 281702
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1202 PM EST WED JAN 28 2015


.AVIATION...

VERY DRY AIR IN THE LOW LEVELS ASSOCIATED WITH HIGH PRESSURE
DEPARTING TO THE EAST WILL MAINTAIN CLEAR SKIES BELOW 10K FT THROUGH
THE AFTERNOON AND EVENING. STRENGTHENING SOUTHERLY FLOW AHEAD OF AN
APPROACHING SFC LOW RAISES SOME CONCERN FOR LOW LEVEL WIND SHEAR
OVERNIGHT WITH WINDS FORECAST TO INCREASE TO 45 KNOTS AT 2K FT.
CURRENT INDICATIONS ARE THAT THERE WILL BE ENOUGH MIXING NEAR THE
SURFACE TO LEAD TO MORE OF A LOW LEVEL TURBULENCE SITUATION /GUSTY
SFC WINDS/ PRIMARILY BETWEEN 08Z THROUGH DAYBREAK. THIS LOW LEVEL
SYSTEM WILL BRING A MIX OF RAIN/SLEET/SNOW TO THE REGION STARTING
ROUGHLY AROUND 12Z. AN EARLIER ARRIVAL OF THE FORCING AND A COLDER
THERMAL PROFILE SUGGESTS ALL SNOW AT MBS...STARTING AROUND OR
SHORTLY AFTER 09Z.

FOR DTW...CONSIDERING THE DEGREE OF WARM AIR ALOFT FORECAST TO
OVERSPREAD METRO DETROIT...PRECIP IS EXPECTED TO START MAINLY AS
FREEZING RAIN. IT SHOULD TRANSITION OVER TO PURE RAIN DURING THE
COURSE OF THE MORNING AS SFC TEMPS WARM ABOVE FREEZING.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS BELOW 5000 FT AFTER 10Z.

* MEDIUM IN PRECIP TYPE STARTING AS A FZRA/IP MIX THURS MORNING.

&&

.PREV DISCUSSION...ISSUED 309 AM EST WED JAN 28 2015

SHORT TERM...TODAY AND TONIGHT

AFTER A CHILLY START...TEMPERATURES WILL REBOUND TO NEAR 30 DEGREES
TODAY AS SOUTHERLY WINDS INCREASE IN ADVANCE OF AN APPROACHING WAVE
OF LOW PRESSURE. MOSTLY SUNNY SKIES WILL GIVE WAY TO INCREASING HIGH
CLOUDINESS AS THE LEADING EDGE OF MOISTURE ASSOCIATED WITH THE WAVE
OVERSPREADS THE AREA.

CLOUDS WILL THEN THICKEN AND LOWER GRADUALLY INTO TONIGHT AS THIS
SYSTEM MOVES INTO THE CENTRAL GREAT LAKES WITH LIGHT SNOW LIKELY
DEVELOPING LATE TONIGHT OVER PARTS OF THE AREA. ACCUMULATIONS WILL
BE MINIMAL PRIOR TO 12Z WITH JUST A FEW TENTHS OF AN INCH AT MOST.
TEMPERATURES...MEANWHILE...WILL REMAIN RELATIVELY MILD AS CLOUDS
INCREASE WITH LOWS HOLDING IN THE LOWER 20S.

LONG TERM...

UPPER JET WILL INTENSIFY OVER NORTHERN CANADA TODAY AS EAST PAC
RIDGING BUILDS TOWARD DIGGING HIGH-LATITUDE ENERGY OVER NORTHERN
ALASKA AND THE NW TERRITORIES AT 07Z THIS MORNING. THIS JET
ENHANCEMENT WILL HELP TO AMPLIFY A NORTHERN STREAM TROUGH THAT WILL
ABSORB THE SHORTWAVE OVER SOUTHERN ALBERTA/SASKATCHEWAN THIS MORNING
BY LATE TONIGHT INTO EARLY THURSDAY. THE DIGGING TROUGH WILL ALSO
STEER THE REMNANT BAJA ENERGY OVER WYOMING ACROSS THE OHIO VALLEY.

MERIDIONALLY ORIENTED SURFACE TROUGH WILL TRANSIT THE STATE ON
THURSDAY, ANCHORED ON BOTH ENDS BY WEAK LOW PRESSURE CENTERS TIED TO
NORTHERN & SOUTHERN FORCING MAXIMA ACCORDINGLY. AS NOTED IN THE
PREVIOUS FORECAST PACKAGE, IT IS REASONABLE TO RESPECT MODEL
SOLUTIONS LEANING TOWARD A STRONGER SOUTHERN WAVE GIVEN LIMITED
UPSTREAM STATIC STABILITY THAT WILL FAVOR STRONGER LARGE SCALE
ASCENT. THE 00Z GFS HAS, IN FACT, TRENDED IN THIS DIRECTION. THE
ECMWF HAS SHOWN LITTLE CHANGE AND DEPICTS A MORE OPEN SURFACE
CIRCULATION, BUT STILL STRONGER THAN THE REMAINING GUIDANCE. RESPECT
IS GIVEN TO THE 00Z GFS, BUT AS A 4+MB OUTLIER AT THIS RATHER SHORT
LEAD TIME, DECIDED AGAINST A FULL BUY-IN.

EXPECTATIONS FOR GENERAL EVOLUTION REMAIN LARGELY UNCHANGED
REGARDLESS. LOW-LEVEL JET RESPONSE WILL DEVELOP OVER THE MIDDLE
MISSISSIPPI VALLEY WITHIN BROADER SOUTHERLY FLOW REGIME TODAY BEFORE
PROGRESSING EAST ACROSS THE AREA 6-12Z TONIGHT. WARMING OF THE MID-
LEVELS WILL BRING BRIEF BUT WELL-DEFINED WINDOW FOR FREEZING RAIN
ACROSS SOUTHERN AREAS DURING THE MORNING. ONGOING SURFACE WARM
ADVECTION AND DIURNAL HEATING WILL JEOPARDIZE SNOW CHANCES SOUTH OF
AT LEAST I-94 FOR THE NEXT SEVERAL HOURS WHERE MIDDAY CONDITIONS
WILL BE STRONGLY DEPENDENT ON THE STRENGTH OF THE SURFACE LOW. NORTH
OF I-69, WEAK DEFORMATION AND MORE FAVORABLE THERMODYNAMIC PROFILES
SHOULD HELP TRANSLATE 0.25" QPF INTO 2-3" OF SNOW ACCUMULATION. IN
BETWEEN, MAINLY SNOW IS EXPECTED BETWEEN ROUGHLY I-696/M59, ALTHOUGH
A DEEP LAYER OF TEMPERATURES DECIDEDLY WARMER THAN -10C THROUGH THE
LOWEST 10KFT WILL SIGNIFICANTLY REDUCE SNOW RATIOS. HERE,
ACCUMULATIONS ARE FORECAST TO RANGE FROM 0.5 TO 1.5". THE BEST SHOT
OF ACCUMULATING SNOW FOR THE SOUTHERN 2/3 OF THE AREA WILL MOST
LIKELY BE IMMEDIATELY IN THE WAKE OF THE SURFACE COLD FRONT AFTER
20Z, WHEN COOLING THERMAL PROFILES WILL SUPPORT BETTER DENDRITE
PRODUCTION PRIOR TO THE EXIT OF THE DEEPER MOISTURE.

DIGGING HIGH-LATITUDE ENERGY WILL PUSH A STRONG COLD FRONT THROUGH
THE AREA FROM NW TO SE THURSDAY NIGHT. THIS SHOT OF COLD ADVECTION
WILL DROP 925MB TEMPERATURES FROM A PEAK OF NEAR 0C DURING THURS
AFTERNOON TO -17C FRIDAY MORNING. NORTHWEST FETCH SHOULD DEFLECT ANY
LAKE EFFECT TO THE SOUTHWEST, BUT BOTH LAKE CLOUDS AND LES LOOK TO
BE HARD TO COME BY GIVEN MODEL DEPICTIONS OF RAPIDLY BUILDING HIGH
PRESSURE THURSDAY NIGHT. HIGHS FRIDAY WILL BE LIMITED TO THE
MID/UPPER TEENS IN MOST SPOTS DESPITE PROSPECTS FOR MOSTLY SUNNY
SKIES. QUICK REBOUND OF THE HEIGHT FIELD DOWNSTREAM OF PAC ENERGY
STREAMING INTO THE WESTERN U.S. WILL HELP TEMPS RECOVER INTO THE MID
20S ON SATURDAY.

FINALLY, MODEL CONSENSUS IS INCREASING THAT A WIDE SWATH OF
ACCUMULATING SNOW WILL DEVELOP OVER THE OHIO VALLEY AND GREAT LAKES
SATURDAY NIGHT INTO SUNDAY NIGHT. THIS WILL OCCUR AS A NORTHERN WAVE
DIGS INTO THE WESTERN PLAINS AND ENTRAINS A HIGHLY UNCERTAIN
PERCENTAGE OF ENERGY FROM A CLOSED LOW OVER THE 4 CORNERS. BROAD
REGION OF NORTHWARD MOISTURE TRANSPORT AND STRONG LARGE SCALE RIGHT
ENTRANCE JET SUPPORT FAVOR RETAINING THE ENTRY-LEVEL LIKELY POPS
INTRODUCED BY THE BLENDED EXTENDED GRIDS.

MARINE...

FRESH TO STRONG SOUTHERLY WINDS WILL DEVELOP LATE TONIGHT INTO
THURSDAY MORNING AS A WEAK LOW PRESSURE SYSTEM TRAVERSES THE GREAT
LAKES. STABLE SOUTHERLY FLOW REGIME WILL LIMIT THE POTENTIAL FOR
WIND GUSTS. THEREFORE...WHILE AN ISOLATED GUST TO GALE FORCE IS
POSSIBLE OVER LAKE HURON...COVERAGE AND DURATION WILL MEET GALE
CRITERIA. A STRONG COLD FRONT WILL THEN SURGE ACROSS THE WATERS ON
THURSDAY NIGHT. MUCH COLDER NORTHWEST FLOW WILL SUPPORT WIDESPREAD
GUSTS TO STRONG GALES ACROSS ALL OF LAKE HURON INCLUDING THE
NEARSHORE WATERS. SIGNIFICANT WAVE HEIGHTS WILL EXCEED 12 FEET OVER
THE SOUTHERN HALF OF LAKE HURON BY LATE THURSDAY NIGHT. WINDS AND
WAVES WILL SUBSIDE FRIDAY INTO FRIDAY NIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR
     LHZ361>363-421-441>443-462>464.

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

$$

AVIATION.....SC
SHORT TERM...DG
LONG TERM....JVC
MARINE.......JVC


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




000
FXUS63 KDTX 281052
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
552 AM EST WED JAN 28 2015


.AVIATION...

HIGH PRESSURE WILL BRING VFR CONDITIONS TODAY...BUT CLOUDS
WILL INCREASE TONIGHT AS THIS HIGH SHIFTS EAST AND LOW PRESSURE
APPROACHES FROM THE WEST. CIGS SHOULD REMAIN AOA 10KFT OR SO MUCH OF
THE NIGHT...BUT MVFR CIGS/VSBYS WILL LIKELY DEVELOP KMBS/KFNT AFTER
09Z-10Z AS -SN BR WORK INTO THE AREA WITH THIS SYSTEM.

FOR DTW...LIGHT SNOW AND MVFR CONDITIONS SHOULD HOLD OFF UNTIL AFTER
12Z THURSDAY.

//DTW THRESHOLD PROBABILITIES...

* LOW IN CIGS AOB 5000 FEET LATE TONIGHT...WITH HIGHER CONFIDENCE
  THURSDAY MORNING.

&&

.PREV DISCUSSION...ISSUED 309 AM EST WED JAN 28 2015

SHORT TERM...TODAY AND TONIGHT

AFTER A CHILLY START...TEMPERATURES WILL REBOUND TO NEAR 30 DEGREES
TODAY AS SOUTHERLY WINDS INCREASE IN ADVANCE OF AN APPROACHING WAVE
OF LOW PRESSURE. MOSTLY SUNNY SKIES WILL GIVE WAY TO INCREASING HIGH
CLOUDINESS AS THE LEADING EDGE OF MOISTURE ASSOCIATED WITH THE WAVE
OVERSPREADS THE AREA.

CLOUDS WILL THEN THICKEN AND LOWER GRADUALLY INTO TONIGHT AS THIS
SYSTEM MOVES INTO THE CENTRAL GREAT LAKES WITH LIGHT SNOW LIKELY
DEVELOPING LATE TONIGHT OVER PARTS OF THE AREA. ACCUMULATIONS WILL
BE MINIMAL PRIOR TO 12Z WITH JUST A FEW TENTHS OF AN INCH AT MOST.
TEMPERATURES...MEANWHILE...WILL REMAIN RELATIVELY MILD AS CLOUDS
INCREASE WITH LOWS HOLDING IN THE LOWER 20S.

LONG TERM...

UPPER JET WILL INTENSIFY OVER NORTHERN CANADA TODAY AS EAST PAC
RIDGING BUILDS TOWARD DIGGING HIGH-LATITUDE ENERGY OVER NORTHERN
ALASKA AND THE NW TERRITORIES AT 07Z THIS MORNING. THIS JET
ENHANCEMENT WILL HELP TO AMPLIFY A NORTHERN STREAM TROUGH THAT WILL
ABSORB THE SHORTWAVE OVER SOUTHERN ALBERTA/SASKATCHEWAN THIS MORNING
BY LATE TONIGHT INTO EARLY THURSDAY. THE DIGGING TROUGH WILL ALSO
STEER THE REMNANT BAJA ENERGY OVER WYOMING ACROSS THE OHIO VALLEY.

MERIDIONALLY ORIENTED SURFACE TROUGH WILL TRANSIT THE STATE ON
THURSDAY, ANCHORED ON BOTH ENDS BY WEAK LOW PRESSURE CENTERS TIED TO
NORTHERN & SOUTHERN FORCING MAXIMA ACCORDINGLY. AS NOTED IN THE
PREVIOUS FORECAST PACKAGE, IT IS REASONABLE TO RESPECT MODEL
SOLUTIONS LEANING TOWARD A STRONGER SOUTHERN WAVE GIVEN LIMITED
UPSTREAM STATIC STABILITY THAT WILL FAVOR STRONGER LARGE SCALE
ASCENT. THE 00Z GFS HAS, IN FACT, TRENDED IN THIS DIRECTION. THE
ECMWF HAS SHOWN LITTLE CHANGE AND DEPICTS A MORE OPEN SURFACE
CIRCULATION, BUT STILL STRONGER THAN THE REMAINING GUIDANCE. RESPECT
IS GIVEN TO THE 00Z GFS, BUT AS A 4+MB OUTLIER AT THIS RATHER SHORT
LEAD TIME, DECIDED AGAINST A FULL BUY-IN.

EXPECTATIONS FOR GENERAL EVOLUTION REMAIN LARGELY UNCHANGED
REGARDLESS. LOW-LEVEL JET RESPONSE WILL DEVELOP OVER THE MIDDLE
MISSISSIPPI VALLEY WITHIN BROADER SOUTHERLY FLOW REGIME TODAY BEFORE
PROGRESSING EAST ACROSS THE AREA 6-12Z TONIGHT. WARMING OF THE MID-
LEVELS WILL BRING BRIEF BUT WELL-DEFINED WINDOW FOR FREEZING RAIN
ACROSS SOUTHERN AREAS DURING THE MORNING. ONGOING SURFACE WARM
ADVECTION AND DIURNAL HEATING WILL JEOPARDIZE SNOW CHANCES SOUTH OF
AT LEAST I-94 FOR THE NEXT SEVERAL HOURS WHERE MIDDAY CONDITIONS
WILL BE STRONGLY DEPENDENT ON THE STRENGTH OF THE SURFACE LOW. NORTH
OF I-69, WEAK DEFORMATION AND MORE FAVORABLE THERMODYNAMIC PROFILES
SHOULD HELP TRANSLATE 0.25" QPF INTO 2-3" OF SNOW ACCUMULATION. IN
BETWEEN, MAINLY SNOW IS EXPECTED BETWEEN ROUGHLY I-696/M59, ALTHOUGH
A DEEP LAYER OF TEMPERATURES DECIDEDLY WARMER THAN -10C THROUGH THE
LOWEST 10KFT WILL SIGNIFICANTLY REDUCE SNOW RATIOS. HERE,
ACCUMULATIONS ARE FORECAST TO RANGE FROM 0.5 TO 1.5". THE BEST SHOT
OF ACCUMULATING SNOW FOR THE SOUTHERN 2/3 OF THE AREA WILL MOST
LIKELY BE IMMEDIATELY IN THE WAKE OF THE SURFACE COLD FRONT AFTER
20Z, WHEN COOLING THERMAL PROFILES WILL SUPPORT BETTER DENDRITE
PRODUCTION PRIOR TO THE EXIT OF THE DEEPER MOISTURE.

DIGGING HIGH-LATITUDE ENERGY WILL PUSH A STRONG COLD FRONT THROUGH
THE AREA FROM NW TO SE THURSDAY NIGHT. THIS SHOT OF COLD ADVECTION
WILL DROP 925MB TEMPERATURES FROM A PEAK OF NEAR 0C DURING THURS
AFTERNOON TO -17C FRIDAY MORNING. NORTHWEST FETCH SHOULD DEFLECT ANY
LAKE EFFECT TO THE SOUTHWEST, BUT BOTH LAKE CLOUDS AND LES LOOK TO
BE HARD TO COME BY GIVEN MODEL DEPICTIONS OF RAPIDLY BUILDING HIGH
PRESSURE THURSDAY NIGHT. HIGHS FRIDAY WILL BE LIMITED TO THE
MID/UPPER TEENS IN MOST SPOTS DESPITE PROSPECTS FOR MOSTLY SUNNY
SKIES. QUICK REBOUND OF THE HEIGHT FIELD DOWNSTREAM OF PAC ENERGY
STREAMING INTO THE WESTERN U.S. WILL HELP TEMPS RECOVER INTO THE MID
20S ON SATURDAY.

FINALLY, MODEL CONSENSUS IS INCREASING THAT A WIDE SWATH OF
ACCUMULATING SNOW WILL DEVELOP OVER THE OHIO VALLEY AND GREAT LAKES
SATURDAY NIGHT INTO SUNDAY NIGHT. THIS WILL OCCUR AS A NORTHERN WAVE
DIGS INTO THE WESTERN PLAINS AND ENTRAINS A HIGHLY UNCERTAIN
PERCENTAGE OF ENERGY FROM A CLOSED LOW OVER THE 4 CORNERS. BROAD
REGION OF NORTHWARD MOISTURE TRANSPORT AND STRONG LARGE SCALE RIGHT
ENTRANCE JET SUPPORT FAVOR RETAINING THE ENTRY-LEVEL LIKELY POPS
INTRODUCED BY THE BLENDED EXTENDED GRIDS.

MARINE...

FRESH TO STRONG SOUTHERLY WINDS WILL DEVELOP LATE TONIGHT INTO
THURSDAY MORNING AS A WEAK LOW PRESSURE SYSTEM TRAVERSES THE GREAT
LAKES. STABLE SOUTHERLY FLOW REGIME WILL LIMIT THE POTENTIAL FOR
WIND GUSTS. THEREFORE...WHILE AN ISOLATED GUST TO GALE FORCE IS
POSSIBLE OVER LAKE HURON...COVERAGE AND DURATION WILL MEET GALE
CRITERIA. A STRONG COLD FRONT WILL THEN SURGE ACROSS THE WATERS ON
THURSDAY NIGHT. MUCH COLDER NORTHWEST FLOW WILL SUPPORT WIDESPREAD
GUSTS TO STRONG GALES ACROSS ALL OF LAKE HURON INCLUDING THE
NEARSHORE WATERS. SIGNIFICANT WAVE HEIGHTS WILL EXCEED 12 FEET OVER
THE SOUTHERN HALF OF LAKE HURON BY LATE THURSDAY NIGHT. WINDS AND
WAVES WILL SUBSIDE FRIDAY INTO FRIDAY NIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR
     LHZ361>363-421-441>443-462>464.

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

$$

AVIATION.....DG
SHORT TERM...DG
LONG TERM....JVC
MARINE.......JVC


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




000
FXUS63 KDTX 281052
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
552 AM EST WED JAN 28 2015


.AVIATION...

HIGH PRESSURE WILL BRING VFR CONDITIONS TODAY...BUT CLOUDS
WILL INCREASE TONIGHT AS THIS HIGH SHIFTS EAST AND LOW PRESSURE
APPROACHES FROM THE WEST. CIGS SHOULD REMAIN AOA 10KFT OR SO MUCH OF
THE NIGHT...BUT MVFR CIGS/VSBYS WILL LIKELY DEVELOP KMBS/KFNT AFTER
09Z-10Z AS -SN BR WORK INTO THE AREA WITH THIS SYSTEM.

FOR DTW...LIGHT SNOW AND MVFR CONDITIONS SHOULD HOLD OFF UNTIL AFTER
12Z THURSDAY.

//DTW THRESHOLD PROBABILITIES...

* LOW IN CIGS AOB 5000 FEET LATE TONIGHT...WITH HIGHER CONFIDENCE
  THURSDAY MORNING.

&&

.PREV DISCUSSION...ISSUED 309 AM EST WED JAN 28 2015

SHORT TERM...TODAY AND TONIGHT

AFTER A CHILLY START...TEMPERATURES WILL REBOUND TO NEAR 30 DEGREES
TODAY AS SOUTHERLY WINDS INCREASE IN ADVANCE OF AN APPROACHING WAVE
OF LOW PRESSURE. MOSTLY SUNNY SKIES WILL GIVE WAY TO INCREASING HIGH
CLOUDINESS AS THE LEADING EDGE OF MOISTURE ASSOCIATED WITH THE WAVE
OVERSPREADS THE AREA.

CLOUDS WILL THEN THICKEN AND LOWER GRADUALLY INTO TONIGHT AS THIS
SYSTEM MOVES INTO THE CENTRAL GREAT LAKES WITH LIGHT SNOW LIKELY
DEVELOPING LATE TONIGHT OVER PARTS OF THE AREA. ACCUMULATIONS WILL
BE MINIMAL PRIOR TO 12Z WITH JUST A FEW TENTHS OF AN INCH AT MOST.
TEMPERATURES...MEANWHILE...WILL REMAIN RELATIVELY MILD AS CLOUDS
INCREASE WITH LOWS HOLDING IN THE LOWER 20S.

LONG TERM...

UPPER JET WILL INTENSIFY OVER NORTHERN CANADA TODAY AS EAST PAC
RIDGING BUILDS TOWARD DIGGING HIGH-LATITUDE ENERGY OVER NORTHERN
ALASKA AND THE NW TERRITORIES AT 07Z THIS MORNING. THIS JET
ENHANCEMENT WILL HELP TO AMPLIFY A NORTHERN STREAM TROUGH THAT WILL
ABSORB THE SHORTWAVE OVER SOUTHERN ALBERTA/SASKATCHEWAN THIS MORNING
BY LATE TONIGHT INTO EARLY THURSDAY. THE DIGGING TROUGH WILL ALSO
STEER THE REMNANT BAJA ENERGY OVER WYOMING ACROSS THE OHIO VALLEY.

MERIDIONALLY ORIENTED SURFACE TROUGH WILL TRANSIT THE STATE ON
THURSDAY, ANCHORED ON BOTH ENDS BY WEAK LOW PRESSURE CENTERS TIED TO
NORTHERN & SOUTHERN FORCING MAXIMA ACCORDINGLY. AS NOTED IN THE
PREVIOUS FORECAST PACKAGE, IT IS REASONABLE TO RESPECT MODEL
SOLUTIONS LEANING TOWARD A STRONGER SOUTHERN WAVE GIVEN LIMITED
UPSTREAM STATIC STABILITY THAT WILL FAVOR STRONGER LARGE SCALE
ASCENT. THE 00Z GFS HAS, IN FACT, TRENDED IN THIS DIRECTION. THE
ECMWF HAS SHOWN LITTLE CHANGE AND DEPICTS A MORE OPEN SURFACE
CIRCULATION, BUT STILL STRONGER THAN THE REMAINING GUIDANCE. RESPECT
IS GIVEN TO THE 00Z GFS, BUT AS A 4+MB OUTLIER AT THIS RATHER SHORT
LEAD TIME, DECIDED AGAINST A FULL BUY-IN.

EXPECTATIONS FOR GENERAL EVOLUTION REMAIN LARGELY UNCHANGED
REGARDLESS. LOW-LEVEL JET RESPONSE WILL DEVELOP OVER THE MIDDLE
MISSISSIPPI VALLEY WITHIN BROADER SOUTHERLY FLOW REGIME TODAY BEFORE
PROGRESSING EAST ACROSS THE AREA 6-12Z TONIGHT. WARMING OF THE MID-
LEVELS WILL BRING BRIEF BUT WELL-DEFINED WINDOW FOR FREEZING RAIN
ACROSS SOUTHERN AREAS DURING THE MORNING. ONGOING SURFACE WARM
ADVECTION AND DIURNAL HEATING WILL JEOPARDIZE SNOW CHANCES SOUTH OF
AT LEAST I-94 FOR THE NEXT SEVERAL HOURS WHERE MIDDAY CONDITIONS
WILL BE STRONGLY DEPENDENT ON THE STRENGTH OF THE SURFACE LOW. NORTH
OF I-69, WEAK DEFORMATION AND MORE FAVORABLE THERMODYNAMIC PROFILES
SHOULD HELP TRANSLATE 0.25" QPF INTO 2-3" OF SNOW ACCUMULATION. IN
BETWEEN, MAINLY SNOW IS EXPECTED BETWEEN ROUGHLY I-696/M59, ALTHOUGH
A DEEP LAYER OF TEMPERATURES DECIDEDLY WARMER THAN -10C THROUGH THE
LOWEST 10KFT WILL SIGNIFICANTLY REDUCE SNOW RATIOS. HERE,
ACCUMULATIONS ARE FORECAST TO RANGE FROM 0.5 TO 1.5". THE BEST SHOT
OF ACCUMULATING SNOW FOR THE SOUTHERN 2/3 OF THE AREA WILL MOST
LIKELY BE IMMEDIATELY IN THE WAKE OF THE SURFACE COLD FRONT AFTER
20Z, WHEN COOLING THERMAL PROFILES WILL SUPPORT BETTER DENDRITE
PRODUCTION PRIOR TO THE EXIT OF THE DEEPER MOISTURE.

DIGGING HIGH-LATITUDE ENERGY WILL PUSH A STRONG COLD FRONT THROUGH
THE AREA FROM NW TO SE THURSDAY NIGHT. THIS SHOT OF COLD ADVECTION
WILL DROP 925MB TEMPERATURES FROM A PEAK OF NEAR 0C DURING THURS
AFTERNOON TO -17C FRIDAY MORNING. NORTHWEST FETCH SHOULD DEFLECT ANY
LAKE EFFECT TO THE SOUTHWEST, BUT BOTH LAKE CLOUDS AND LES LOOK TO
BE HARD TO COME BY GIVEN MODEL DEPICTIONS OF RAPIDLY BUILDING HIGH
PRESSURE THURSDAY NIGHT. HIGHS FRIDAY WILL BE LIMITED TO THE
MID/UPPER TEENS IN MOST SPOTS DESPITE PROSPECTS FOR MOSTLY SUNNY
SKIES. QUICK REBOUND OF THE HEIGHT FIELD DOWNSTREAM OF PAC ENERGY
STREAMING INTO THE WESTERN U.S. WILL HELP TEMPS RECOVER INTO THE MID
20S ON SATURDAY.

FINALLY, MODEL CONSENSUS IS INCREASING THAT A WIDE SWATH OF
ACCUMULATING SNOW WILL DEVELOP OVER THE OHIO VALLEY AND GREAT LAKES
SATURDAY NIGHT INTO SUNDAY NIGHT. THIS WILL OCCUR AS A NORTHERN WAVE
DIGS INTO THE WESTERN PLAINS AND ENTRAINS A HIGHLY UNCERTAIN
PERCENTAGE OF ENERGY FROM A CLOSED LOW OVER THE 4 CORNERS. BROAD
REGION OF NORTHWARD MOISTURE TRANSPORT AND STRONG LARGE SCALE RIGHT
ENTRANCE JET SUPPORT FAVOR RETAINING THE ENTRY-LEVEL LIKELY POPS
INTRODUCED BY THE BLENDED EXTENDED GRIDS.

MARINE...

FRESH TO STRONG SOUTHERLY WINDS WILL DEVELOP LATE TONIGHT INTO
THURSDAY MORNING AS A WEAK LOW PRESSURE SYSTEM TRAVERSES THE GREAT
LAKES. STABLE SOUTHERLY FLOW REGIME WILL LIMIT THE POTENTIAL FOR
WIND GUSTS. THEREFORE...WHILE AN ISOLATED GUST TO GALE FORCE IS
POSSIBLE OVER LAKE HURON...COVERAGE AND DURATION WILL MEET GALE
CRITERIA. A STRONG COLD FRONT WILL THEN SURGE ACROSS THE WATERS ON
THURSDAY NIGHT. MUCH COLDER NORTHWEST FLOW WILL SUPPORT WIDESPREAD
GUSTS TO STRONG GALES ACROSS ALL OF LAKE HURON INCLUDING THE
NEARSHORE WATERS. SIGNIFICANT WAVE HEIGHTS WILL EXCEED 12 FEET OVER
THE SOUTHERN HALF OF LAKE HURON BY LATE THURSDAY NIGHT. WINDS AND
WAVES WILL SUBSIDE FRIDAY INTO FRIDAY NIGHT.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR
     LHZ361>363-421-441>443-462>464.

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

$$

AVIATION.....DG
SHORT TERM...DG
LONG TERM....JVC
MARINE.......JVC


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





000
FXUS63 KDTX 280809
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
309 AM EST WED JAN 28 2015

.SHORT TERM...TODAY AND TONIGHT

AFTER A CHILLY START...TEMPERATURES WILL REBOUND TO NEAR 30 DEGREES
TODAY AS SOUTHERLY WINDS INCREASE IN ADVANCE OF AN APPROACHING WAVE
OF LOW PRESSURE. MOSTLY SUNNY SKIES WILL GIVE WAY TO INCREASING HIGH
CLOUDINESS AS THE LEADING EDGE OF MOISTURE ASSOCIATED WITH THE WAVE
OVERSPREADS THE AREA.

CLOUDS WILL THEN THICKEN AND LOWER GRADUALLY INTO TONIGHT AS THIS
SYSTEM MOVES INTO THE CENTRAL GREAT LAKES WITH LIGHT SNOW LIKELY
DEVELOPING LATE TONIGHT OVER PARTS OF THE AREA. ACCUMULATIONS WILL
BE MINIMAL PRIOR TO 12Z WITH JUST A FEW TENTHS OF AN INCH AT MOST.
TEMPERATURES...MEANWHILE...WILL REMAIN RELATIVELY MILD AS CLOUDS
INCREASE WITH LOWS HOLDING IN THE LOWER 20S.

&&

.LONG TERM...

UPPER JET WILL INTENSIFY OVER NORTHERN CANADA TODAY AS EAST PAC
RIDGING BUILDS TOWARD DIGGING HIGH-LATITUDE ENERGY OVER NORTHERN
ALASKA AND THE NW TERRITORIES AT 07Z THIS MORNING. THIS JET
ENHANCEMENT WILL HELP TO AMPLIFY A NORTHERN STREAM TROUGH THAT WILL
ABSORB THE SHORTWAVE OVER SOUTHERN ALBERTA/SASKATCHEWAN THIS MORNING
BY LATE TONIGHT INTO EARLY THURSDAY. THE DIGGING TROUGH WILL ALSO
STEER THE REMNANT BAJA ENERGY OVER WYOMING ACROSS THE OHIO VALLEY.

MERIDIONALLY ORIENTED SURFACE TROUGH WILL TRANSIT THE STATE ON
THURSDAY, ANCHORED ON BOTH ENDS BY WEAK LOW PRESSURE CENTERS TIED TO
NORTHERN & SOUTHERN FORCING MAXIMA ACCORDINGLY. AS NOTED IN THE
PREVIOUS FORECAST PACKAGE, IT IS REASONABLE TO RESPECT MODEL
SOLUTIONS LEANING TOWARD A STRONGER SOUTHERN WAVE GIVEN LIMITED
UPSTREAM STATIC STABILITY THAT WILL FAVOR STRONGER LARGE SCALE
ASCENT. THE 00Z GFS HAS, IN FACT, TRENDED IN THIS DIRECTION. THE
ECMWF HAS SHOWN LITTLE CHANGE AND DEPICTS A MORE OPEN SURFACE
CIRCULATION, BUT STILL STRONGER THAN THE REMAINING GUIDANCE. RESPECT
IS GIVEN TO THE 00Z GFS, BUT AS A 4+MB OUTLIER AT THIS RATHER SHORT
LEAD TIME, DECIDED AGAINST A FULL BUY-IN.

EXPECTATIONS FOR GENERAL EVOLUTION REMAIN LARGELY UNCHANGED
REGARDLESS. LOW-LEVEL JET RESPONSE WILL DEVELOP OVER THE MIDDLE
MISSISSIPPI VALLEY WITHIN BROADER SOUTHERLY FLOW REGIME TODAY BEFORE
PROGRESSING EAST ACROSS THE AREA 6-12Z TONIGHT. WARMING OF THE MID-
LEVELS WILL BRING BRIEF BUT WELL-DEFINED WINDOW FOR FREEZING RAIN
ACROSS SOUTHERN AREAS DURING THE MORNING. ONGOING SURFACE WARM
ADVECTION AND DIURNAL HEATING WILL JEOPARDIZE SNOW CHANCES SOUTH OF
AT LEAST I-94 FOR THE NEXT SEVERAL HOURS WHERE MIDDAY CONDITIONS
WILL BE STRONGLY DEPENDENT ON THE STRENGTH OF THE SURFACE LOW. NORTH
OF I-69, WEAK DEFORMATION AND MORE FAVORABLE THERMODYNAMIC PROFILES
SHOULD HELP TRANSLATE 0.25" QPF INTO 2-3" OF SNOW ACCUMULATION. IN
BETWEEN, MAINLY SNOW IS EXPECTED BETWEEN ROUGHLY I-696/M59, ALTHOUGH
A DEEP LAYER OF TEMPERATURES DECIDEDLY WARMER THAN -10C THROUGH THE
LOWEST 10KFT WILL SIGNIFICANTLY REDUCE SNOW RATIOS. HERE,
ACCUMULATIONS ARE FORECAST TO RANGE FROM 0.5 TO 1.5". THE BEST SHOT
OF ACCUMULATING SNOW FOR THE SOUTHERN 2/3 OF THE AREA WILL MOST
LIKELY BE IMMEDIATELY IN THE WAKE OF THE SURFACE COLD FRONT AFTER
20Z, WHEN COOLING THERMAL PROFILES WILL SUPPORT BETTER DENDRITE
PRODUCTION PRIOR TO THE EXIT OF THE DEEPER MOISTURE.

DIGGING HIGH-LATITUDE ENERGY WILL PUSH A STRONG COLD FRONT THROUGH
THE AREA FROM NW TO SE THURSDAY NIGHT. THIS SHOT OF COLD ADVECTION
WILL DROP 925MB TEMPERATURES FROM A PEAK OF NEAR 0C DURING THURS
AFTERNOON TO -17C FRIDAY MORNING. NORTHWEST FETCH SHOULD DEFLECT ANY
LAKE EFFECT TO THE SOUTHWEST, BUT BOTH LAKE CLOUDS AND LES LOOK TO
BE HARD TO COME BY GIVEN MODEL DEPICTIONS OF RAPIDLY BUILDING HIGH
PRESSURE THURSDAY NIGHT. HIGHS FRIDAY WILL BE LIMITED TO THE
MID/UPPER TEENS IN MOST SPOTS DESPITE PROSPECTS FOR MOSTLY SUNNY
SKIES. QUICK REBOUND OF THE HEIGHT FIELD DOWNSTREAM OF PAC ENERGY
STREAMING INTO THE WESTERN U.S. WILL HELP TEMPS RECOVER INTO THE MID
20S ON SATURDAY.

FINALLY, MODEL CONSENSUS IS INCREASING THAT A WIDE SWATH OF
ACCUMULATING SNOW WILL DEVELOP OVER THE OHIO VALLEY AND GREAT LAKES
SATURDAY NIGHT INTO SUNDAY NIGHT. THIS WILL OCCUR AS A NORTHERN WAVE
DIGS INTO THE WESTERN PLAINS AND ENTRAINS A HIGHLY UNCERTAIN
PERCENTAGE OF ENERGY FROM A CLOSED LOW OVER THE 4 CORNERS. BROAD
REGION OF NORTHWARD MOISTURE TRANSPORT AND STRONG LARGE SCALE RIGHT
ENTRANCE JET SUPPORT FAVOR RETAINING THE ENTRY-LEVEL LIKELY POPS
INTRODUCED BY THE BLENDED EXTENDED GRIDS.

&&

.MARINE...

FRESH TO STRONG SOUTHERLY WINDS WILL DEVELOP LATE TONIGHT INTO
THURSDAY MORNING AS A WEAK LOW PRESSURE SYSTEM TRAVERSES THE GREAT
LAKES. STABLE SOUTHERLY FLOW REGIME WILL LIMIT THE POTENTIAL FOR
WIND GUSTS. THEREFORE...WHILE AN ISOLATED GUST TO GALE FORCE IS
POSSIBLE OVER LAKE HURON...COVERAGE AND DURATION WILL MEET GALE
CRITERIA. A STRONG COLD FRONT WILL THEN SURGE ACROSS THE WATERS ON
THURSDAY NIGHT. MUCH COLDER NORTHWEST FLOW WILL SUPPORT WIDESPREAD
GUSTS TO STRONG GALES ACROSS ALL OF LAKE HURON INCLUDING THE
NEARSHORE WATERS. SIGNIFICANT WAVE HEIGHTS WILL EXCEED 12 FEET OVER
THE SOUTHERN HALF OF LAKE HURON BY LATE THURSDAY NIGHT. WINDS AND
WAVES WILL SUBSIDE FRIDAY INTO FRIDAY NIGHT.

&&

.AVIATION...ISSUED 1137 PM EST TUE JAN 27 2015

PRIMARILY VFR CONDITIONS THROUGH THE TAF CYCLE AS AN AREA OF HIGH
PRESSURE SLIDES THROUGH THE REGION. WINDS WILL BE LIGHT AND VARIABLE
OVERNIGHT...BECOMING SOUTHERLY WEDNESDAY AFTERNOON AS THE HIGH
SLIDES OFF TO THE EAST.

//DTW THRESHOLD PROBABILITIES...

* NONE.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR
     LHZ361>363-421-441>443-462>464.

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

$$

SHORT TERM...DG
LONG TERM....JVC
MARINE.......JVC
AVIATION.....KURIMSKI


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




000
FXUS63 KDTX 280809
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
309 AM EST WED JAN 28 2015

.SHORT TERM...TODAY AND TONIGHT

AFTER A CHILLY START...TEMPERATURES WILL REBOUND TO NEAR 30 DEGREES
TODAY AS SOUTHERLY WINDS INCREASE IN ADVANCE OF AN APPROACHING WAVE
OF LOW PRESSURE. MOSTLY SUNNY SKIES WILL GIVE WAY TO INCREASING HIGH
CLOUDINESS AS THE LEADING EDGE OF MOISTURE ASSOCIATED WITH THE WAVE
OVERSPREADS THE AREA.

CLOUDS WILL THEN THICKEN AND LOWER GRADUALLY INTO TONIGHT AS THIS
SYSTEM MOVES INTO THE CENTRAL GREAT LAKES WITH LIGHT SNOW LIKELY
DEVELOPING LATE TONIGHT OVER PARTS OF THE AREA. ACCUMULATIONS WILL
BE MINIMAL PRIOR TO 12Z WITH JUST A FEW TENTHS OF AN INCH AT MOST.
TEMPERATURES...MEANWHILE...WILL REMAIN RELATIVELY MILD AS CLOUDS
INCREASE WITH LOWS HOLDING IN THE LOWER 20S.

&&

.LONG TERM...

UPPER JET WILL INTENSIFY OVER NORTHERN CANADA TODAY AS EAST PAC
RIDGING BUILDS TOWARD DIGGING HIGH-LATITUDE ENERGY OVER NORTHERN
ALASKA AND THE NW TERRITORIES AT 07Z THIS MORNING. THIS JET
ENHANCEMENT WILL HELP TO AMPLIFY A NORTHERN STREAM TROUGH THAT WILL
ABSORB THE SHORTWAVE OVER SOUTHERN ALBERTA/SASKATCHEWAN THIS MORNING
BY LATE TONIGHT INTO EARLY THURSDAY. THE DIGGING TROUGH WILL ALSO
STEER THE REMNANT BAJA ENERGY OVER WYOMING ACROSS THE OHIO VALLEY.

MERIDIONALLY ORIENTED SURFACE TROUGH WILL TRANSIT THE STATE ON
THURSDAY, ANCHORED ON BOTH ENDS BY WEAK LOW PRESSURE CENTERS TIED TO
NORTHERN & SOUTHERN FORCING MAXIMA ACCORDINGLY. AS NOTED IN THE
PREVIOUS FORECAST PACKAGE, IT IS REASONABLE TO RESPECT MODEL
SOLUTIONS LEANING TOWARD A STRONGER SOUTHERN WAVE GIVEN LIMITED
UPSTREAM STATIC STABILITY THAT WILL FAVOR STRONGER LARGE SCALE
ASCENT. THE 00Z GFS HAS, IN FACT, TRENDED IN THIS DIRECTION. THE
ECMWF HAS SHOWN LITTLE CHANGE AND DEPICTS A MORE OPEN SURFACE
CIRCULATION, BUT STILL STRONGER THAN THE REMAINING GUIDANCE. RESPECT
IS GIVEN TO THE 00Z GFS, BUT AS A 4+MB OUTLIER AT THIS RATHER SHORT
LEAD TIME, DECIDED AGAINST A FULL BUY-IN.

EXPECTATIONS FOR GENERAL EVOLUTION REMAIN LARGELY UNCHANGED
REGARDLESS. LOW-LEVEL JET RESPONSE WILL DEVELOP OVER THE MIDDLE
MISSISSIPPI VALLEY WITHIN BROADER SOUTHERLY FLOW REGIME TODAY BEFORE
PROGRESSING EAST ACROSS THE AREA 6-12Z TONIGHT. WARMING OF THE MID-
LEVELS WILL BRING BRIEF BUT WELL-DEFINED WINDOW FOR FREEZING RAIN
ACROSS SOUTHERN AREAS DURING THE MORNING. ONGOING SURFACE WARM
ADVECTION AND DIURNAL HEATING WILL JEOPARDIZE SNOW CHANCES SOUTH OF
AT LEAST I-94 FOR THE NEXT SEVERAL HOURS WHERE MIDDAY CONDITIONS
WILL BE STRONGLY DEPENDENT ON THE STRENGTH OF THE SURFACE LOW. NORTH
OF I-69, WEAK DEFORMATION AND MORE FAVORABLE THERMODYNAMIC PROFILES
SHOULD HELP TRANSLATE 0.25" QPF INTO 2-3" OF SNOW ACCUMULATION. IN
BETWEEN, MAINLY SNOW IS EXPECTED BETWEEN ROUGHLY I-696/M59, ALTHOUGH
A DEEP LAYER OF TEMPERATURES DECIDEDLY WARMER THAN -10C THROUGH THE
LOWEST 10KFT WILL SIGNIFICANTLY REDUCE SNOW RATIOS. HERE,
ACCUMULATIONS ARE FORECAST TO RANGE FROM 0.5 TO 1.5". THE BEST SHOT
OF ACCUMULATING SNOW FOR THE SOUTHERN 2/3 OF THE AREA WILL MOST
LIKELY BE IMMEDIATELY IN THE WAKE OF THE SURFACE COLD FRONT AFTER
20Z, WHEN COOLING THERMAL PROFILES WILL SUPPORT BETTER DENDRITE
PRODUCTION PRIOR TO THE EXIT OF THE DEEPER MOISTURE.

DIGGING HIGH-LATITUDE ENERGY WILL PUSH A STRONG COLD FRONT THROUGH
THE AREA FROM NW TO SE THURSDAY NIGHT. THIS SHOT OF COLD ADVECTION
WILL DROP 925MB TEMPERATURES FROM A PEAK OF NEAR 0C DURING THURS
AFTERNOON TO -17C FRIDAY MORNING. NORTHWEST FETCH SHOULD DEFLECT ANY
LAKE EFFECT TO THE SOUTHWEST, BUT BOTH LAKE CLOUDS AND LES LOOK TO
BE HARD TO COME BY GIVEN MODEL DEPICTIONS OF RAPIDLY BUILDING HIGH
PRESSURE THURSDAY NIGHT. HIGHS FRIDAY WILL BE LIMITED TO THE
MID/UPPER TEENS IN MOST SPOTS DESPITE PROSPECTS FOR MOSTLY SUNNY
SKIES. QUICK REBOUND OF THE HEIGHT FIELD DOWNSTREAM OF PAC ENERGY
STREAMING INTO THE WESTERN U.S. WILL HELP TEMPS RECOVER INTO THE MID
20S ON SATURDAY.

FINALLY, MODEL CONSENSUS IS INCREASING THAT A WIDE SWATH OF
ACCUMULATING SNOW WILL DEVELOP OVER THE OHIO VALLEY AND GREAT LAKES
SATURDAY NIGHT INTO SUNDAY NIGHT. THIS WILL OCCUR AS A NORTHERN WAVE
DIGS INTO THE WESTERN PLAINS AND ENTRAINS A HIGHLY UNCERTAIN
PERCENTAGE OF ENERGY FROM A CLOSED LOW OVER THE 4 CORNERS. BROAD
REGION OF NORTHWARD MOISTURE TRANSPORT AND STRONG LARGE SCALE RIGHT
ENTRANCE JET SUPPORT FAVOR RETAINING THE ENTRY-LEVEL LIKELY POPS
INTRODUCED BY THE BLENDED EXTENDED GRIDS.

&&

.MARINE...

FRESH TO STRONG SOUTHERLY WINDS WILL DEVELOP LATE TONIGHT INTO
THURSDAY MORNING AS A WEAK LOW PRESSURE SYSTEM TRAVERSES THE GREAT
LAKES. STABLE SOUTHERLY FLOW REGIME WILL LIMIT THE POTENTIAL FOR
WIND GUSTS. THEREFORE...WHILE AN ISOLATED GUST TO GALE FORCE IS
POSSIBLE OVER LAKE HURON...COVERAGE AND DURATION WILL MEET GALE
CRITERIA. A STRONG COLD FRONT WILL THEN SURGE ACROSS THE WATERS ON
THURSDAY NIGHT. MUCH COLDER NORTHWEST FLOW WILL SUPPORT WIDESPREAD
GUSTS TO STRONG GALES ACROSS ALL OF LAKE HURON INCLUDING THE
NEARSHORE WATERS. SIGNIFICANT WAVE HEIGHTS WILL EXCEED 12 FEET OVER
THE SOUTHERN HALF OF LAKE HURON BY LATE THURSDAY NIGHT. WINDS AND
WAVES WILL SUBSIDE FRIDAY INTO FRIDAY NIGHT.

&&

.AVIATION...ISSUED 1137 PM EST TUE JAN 27 2015

PRIMARILY VFR CONDITIONS THROUGH THE TAF CYCLE AS AN AREA OF HIGH
PRESSURE SLIDES THROUGH THE REGION. WINDS WILL BE LIGHT AND VARIABLE
OVERNIGHT...BECOMING SOUTHERLY WEDNESDAY AFTERNOON AS THE HIGH
SLIDES OFF TO THE EAST.

//DTW THRESHOLD PROBABILITIES...

* NONE.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR
     LHZ361>363-421-441>443-462>464.

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

$$

SHORT TERM...DG
LONG TERM....JVC
MARINE.......JVC
AVIATION.....KURIMSKI


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





000
FXUS63 KDTX 280437
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1137 PM EST TUE JAN 27 2015


.AVIATION...

PRIMARILY VFR CONDITIONS THROUGH THE TAF CYCLE AS AN AREA OF HIGH
PRESSURE SLIDES THROUGH THE REGION. WINDS WILL BE LIGHT AND VARIABLE
OVERNIGHT...BECOMING SOUTHERLY WEDNESDAY AFTERNOON AS THE HIGH
SLIDES OFF TO THE EAST.

//DTW THRESHOLD PROBABILITIES...

* NONE.

&&

.PREV DISCUSSION...ISSUED 353 PM EST TUE JAN 27 2015

SHORT TERM...THROUGH TONIGHT

QUIET STRETCH OF WEATHER TAKING US THROUGH TONIGHT AS HIGH PRESSURE
CENTERED OVER QUEBEC AND EASTERN ONTARIO DROPS SOUTHWARD THROUGH THE
GREAT LAKES. THE RESULTANT NORTHERLY FLOW WILL USHERS AN
INCREASINGLY DRIER AIRMASS INTO THE STATE. NE FLOW EARLIER IN THE
DAY UTILIZED LAKE HURON MOISTURE TO PRODUCE SOME LAKE EFFECT CLOUDS
OVER MUCH OF THE THUMB BUT AS WINDS TURN MORE NORTHERLY...DRIER AIR
IS ADVECTING INTO THE REGION WHICH IS ERODING THE CURRENT CLOUD
FIELD. THIS WILL HELP EXPEDITE THE PROCESS OF CLEARING THE SKIES OUT
THIS EVENING. WITH THE CLEARING SKIES...DRY AIRMASS AND CALM WINDS
WITH THE SFC HIGH...WE CAN EXPECT ANOTHER NIGHT OF FAVORABLE
RADIATIONAL COOLING. EVEN THOUGHT MID LEVEL HEIGHTS WILL BE ON THE
RISE WITH TEMPS SLOWLY CLIMBING IN THE 900-500MB LAYER...THE BL WILL
REMAIN DECOUPLED AND TEMPS WILL FALL INTO THE SINGLE DIGITS...SOME
10 DEGREES BELOW NORMAL.

LONG TERM...

SURFACE HIGH PRESSURE LINGERING OVER THE REGION WEDNESDAY WILL
ENSURE ONE MORE QUIET WEATHER DAY IN SE MICHIGAN. QUICKLY THICKENING
HIGH CLOUDS DURING THE AFTERNOON WILL BE THE FIRST SIGN OF THE NEXT
LOW PRESSURE SYSTEM SET TO MOVE INTO THE GREAT LAKES THURSDAY WHICH
IS STILL ON TRACK TO BRING A ROUND OF SNOW TO OUR AREA BUT ALSO AT
LEAST A SHORT PERIOD OF MIXED PRECIPITATION FROM THE OHIO BORDER UP
THROUGH THE NORTHERN SUBURBS OF DETROIT. TOTAL ACCUMULATION IN THE 1
TO 3 INCH RANGE REMAINS ON TARGET FOR NOW WITH THE HIGHER END OF THE
RANGE MORE LIKELY IN THE NORTHERN THUMB AND THE LOW END TOWARD THE
OHIO BORDER WHERE A MIX WILL BE A LIMITING FACTOR.

AFTERNOON SATELLITE IMAGERY INDICATES THE UPPER WAVE OVER THE GREAT
BASIN IS BEING PICKED UP BY THE NORTHERN STREAM AND IN GOOD POSITION
TO LATCH ON TO THE ENTRANCE REGION OF THE UPPER JET INTO THE CENTRAL
PLAINS WEDNESDAY. CLOSE BEHIND IS THE NORTHERN STREAM WAVE MOVING
INLAND FROM THE PACIFIC COAST OF CANADA BOTH OF WHICH WILL GET A
BROAD AREA OF SURFACE LOW PRESSURE DEVELOPMENT UNDERWAY OVER THE
PLAINS. THE PRIMARY SURFACE WAVE WILL BE EMBEDDED WITHIN THE STRONG
LOW LEVEL BAROCLINIC ZONE SET UP FROM THE DAKOTAS INTO THE TENNESSEE
VALLEY BY WEDNESDAY AFTERNOON. ASSUMING SUFFICIENT SEPARATION IS
MAINTAINED...A MODEST COUPLED JET STRUCTURE ALOFT WILL AID IN
CONTINUED DEVELOPMENT OF THE LEAD WAVE AND SURFACE LOW. A CROSS
SECTION OF THETA-E FROM THE SOUTHERN PLAINS TO GREAT LAKES ALSO
INDICATES VERY LOW STABILITY IN THE LOW TO MID LEVELS WHICH FAVORS
MODEL SOLUTIONS THAT OFFER A DEEPER SURFACE LOW OR ARE TRENDING
DEEPER WITH THE LOW OVER IOWA WEDNESDAY NIGHT WITH A WEAKER SURFACE
REFLECTION OF THE NORTHERN STREAM WAVE OVER THE NORTHERN GREAT
LAKES. THIS SETS THE STAGE FOR A GREATER AMOUNT OF WARM AIR BEING
DRAWN NORTHWARD FROM THE PLAINS INTO THE MID LEVELS OVER THE GREAT
LAKES AS PRECIPITATION DEVELOPS TOWARD THURSDAY MORNING.

THE 12 HR LIQUID EQUIVALENT QPF IS PUSHING 0.3 INCH IN THE GFS AND
CANADIAN SOLUTIONS FOR THURSDAY WHICH REPRESENTS THE POTENTIAL FOR A
STRONGER SOLUTION ON THE SYSTEM AND A GREATER INFLUENCE OF WET BULB
COOLING ON P-TYPE AT THE ONSET. IT ALSO STILL SUPPORTS A 3 INCH
ACCUMULATION ON THE UPPER END SINCE A SNOW RATIO CLOSER TO OR EVEN
SUB 10:1 IS MORE LIKELY IN THE WARM THERMAL PROFILE. MODEL SOUNDINGS
FROM THE 12Z RUNS AND 09Z SREF MEAN INDICATE ENOUGH DRY AIR IN THE
LOW LEVELS TO LEAN TOWARD SLOWER ONSET TIMING...BUT STILL STARTING
BEFORE SUNRISE...DURING THE MORNING DRIVE...AND IN THE FORM OF SNOW.
A STRONG SOUTHERLY LOW LEVEL JET AVERAGING 45 KNOTS IN THE 900-850
MB LAYER THEN SHOWS POTENTIAL TO QUICKLY DRIVE ENOUGH WARM AIR
NORTHWARD TO OVERWHELM WET BULB EFFECTS AND CHANGE TYPE OVER TO
FREEZING RAIN UP TO ABOUT THE M-59 CORRIDOR. THE AVAILABILITY OF
WARM AIR LOOKS MORE THAN SOLID IN OBSERVATIONS TODAY OVER THE
SOUTHERN PLAINS IN SUPPORT OF A STRONG SURFACE WARM FRONT IN MODEL
DEPICTIONS. AT THE SAME TIME...SUB FREEZING SURFACE AIR WILL BE
ENTRENCHED NORTH OF THE FRONT OVER SE MICHIGAN...SCOURED OUT BRIEFLY
AROUND NOON...AND THEN WARMER AIR WILL BE SWEPT EASTWARD AS THE
SYSTEM OCCLUDES DURING THE AFTERNOON. THIS WILL CHANGE REMAINING
PRECIP BACK OVER TO SNOW BEFORE ENDING THURSDAY EVENING.

DEPARTING TROUGH WILL BE REPLACED BY SLIGHT UPPER LEVEL RIDGING
FRIDAY INTO THE START OF THE WEEKEND.  THE NEW MONTH WILL START OUT
WITH BELOW NORMAL TEMPERATURES...ALONG WITH PERIODS OF ACTIVE
WEATHER.  THINGS WILL THEN CHANGE AS ANOTHER TROUGH DIGS DOWN ACROSS
THE GREAT LAKES COME SUNDAY AS AN AREA OF LOW PRESSURE DEVELOPS
ACROSS THE SOUTH AND MOVES NORTHEAST TOWARDS THE AREA.  THIS SYSTEM
HAS THE POTENTIAL TO BRING SNOW TO THE SOUTHEAST MICHIGAN DEPENDING
ON THE OVERALL TRACK.

MARINE...

HIGH PRESSURE WILL GRADUALLY SHIFT ACROSS THE GREAT LAKES TONIGHT
THROUGH WEDNESDAY MORNING GIVING WAY TO THE NEXT WAVE OF LOW
PRESSURE ARRIVING OVER THE MIDWEST BY WEDNESDAY NIGHT. LAKE HURON
AND LOWER MICHIGAN WILL BE IN BETWEEN THE TWO SYSTEMS WHICH WILL
PRODUCE AN UPTICK IN SOUTHERLY WINDS, BUT GUSTINESS WILL BE LIMITED
TO LESS THAN 30 KNOTS DUE TO WARM STABLE AIR MOVING IN FROM THE
SOUTH. THIS WILL CHANGE BY THURSDAY NIGHT AS COLD AND STRONG
NORTHWEST WIND WILL DEVELOP AS THE LOW EXITS THE GREAT LAKES. A GALE
WATCH IS NOW IN EFFECT FOR POTENTIAL 40 KNOT GUSTS THROUGH FRIDAY
MORNING. LOWER WIND SPEED IS EXPECTED HEADING INTO THE WEEKEND BUT A
RENEWED STRETCH OF ACTIVE MARINE WEATHER IS ANTICIPATED INTO NEXT
WEEK AS MULTIPLE BOUTS OF ARCTIC AIR TRAVERSE THE WATERS.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR
     LHZ361>363-462>464.

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

$$

AVIATION.....KURIMSKI
SHORT TERM...DRK
LONG TERM....BT/SS
MARINE.......BT


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




000
FXUS63 KDTX 272322
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
622 PM EST TUE JAN 27 2015


.AVIATION...

PRIMARILY VFR CONDITIONS THROUGH THE TAF CYCLE AS AN AREA OF HIGH
PRESSURE SLIDES THROUGH THE REGION. WINDS WILL BE LIGHT AND VARIABLE
OVERNIGHT...BECOMING SOUTHERLY WEDNESDAY AFTERNOON AS THE HIGH
SLIDES OFF TO THE EAST.

//DTW THRESHOLD PROBABILITIES...

* NONE.

&&

.PREV DISCUSSION...ISSUED 353 PM EST TUE JAN 27 2015

SHORT TERM...THROUGH TONIGHT

QUIET STRETCH OF WEATHER TAKING US THROUGH TONIGHT AS HIGH PRESSURE
CENTERED OVER QUEBEC AND EASTERN ONTARIO DROPS SOUTHWARD THROUGH THE
GREAT LAKES. THE RESULTANT NORTHERLY FLOW WILL USHERS AN
INCREASINGLY DRIER AIRMASS INTO THE STATE. NE FLOW EARLIER IN THE
DAY UTILIZED LAKE HURON MOISTURE TO PRODUCE SOME LAKE EFFECT CLOUDS
OVER MUCH OF THE THUMB BUT AS WINDS TURN MORE NORTHERLY...DRIER AIR
IS ADVECTING INTO THE REGION WHICH IS ERODING THE CURRENT CLOUD
FIELD. THIS WILL HELP EXPEDITE THE PROCESS OF CLEARING THE SKIES OUT
THIS EVENING. WITH THE CLEARING SKIES...DRY AIRMASS AND CALM WINDS
WITH THE SFC HIGH...WE CAN EXPECT ANOTHER NIGHT OF FAVORABLE
RADIATIONAL COOLING. EVEN THOUGHT MID LEVEL HEIGHTS WILL BE ON THE
RISE WITH TEMPS SLOWLY CLIMBING IN THE 900-500MB LAYER...THE BL WILL
REMAIN DECOUPLED AND TEMPS WILL FALL INTO THE SINGLE DIGITS...SOME
10 DEGREES BELOW NORMAL.

LONG TERM...

SURFACE HIGH PRESSURE LINGERING OVER THE REGION WEDNESDAY WILL
ENSURE ONE MORE QUIET WEATHER DAY IN SE MICHIGAN. QUICKLY THICKENING
HIGH CLOUDS DURING THE AFTERNOON WILL BE THE FIRST SIGN OF THE NEXT
LOW PRESSURE SYSTEM SET TO MOVE INTO THE GREAT LAKES THURSDAY WHICH
IS STILL ON TRACK TO BRING A ROUND OF SNOW TO OUR AREA BUT ALSO AT
LEAST A SHORT PERIOD OF MIXED PRECIPITATION FROM THE OHIO BORDER UP
THROUGH THE NORTHERN SUBURBS OF DETROIT. TOTAL ACCUMULATION IN THE 1
TO 3 INCH RANGE REMAINS ON TARGET FOR NOW WITH THE HIGHER END OF THE
RANGE MORE LIKELY IN THE NORTHERN THUMB AND THE LOW END TOWARD THE
OHIO BORDER WHERE A MIX WILL BE A LIMITING FACTOR.

AFTERNOON SATELLITE IMAGERY INDICATES THE UPPER WAVE OVER THE GREAT
BASIN IS BEING PICKED UP BY THE NORTHERN STREAM AND IN GOOD POSITION
TO LATCH ON TO THE ENTRANCE REGION OF THE UPPER JET INTO THE CENTRAL
PLAINS WEDNESDAY. CLOSE BEHIND IS THE NORTHERN STREAM WAVE MOVING
INLAND FROM THE PACIFIC COAST OF CANADA BOTH OF WHICH WILL GET A
BROAD AREA OF SURFACE LOW PRESSURE DEVELOPMENT UNDERWAY OVER THE
PLAINS. THE PRIMARY SURFACE WAVE WILL BE EMBEDDED WITHIN THE STRONG
LOW LEVEL BAROCLINIC ZONE SET UP FROM THE DAKOTAS INTO THE TENNESSEE
VALLEY BY WEDNESDAY AFTERNOON. ASSUMING SUFFICIENT SEPARATION IS
MAINTAINED...A MODEST COUPLED JET STRUCTURE ALOFT WILL AID IN
CONTINUED DEVELOPMENT OF THE LEAD WAVE AND SURFACE LOW. A CROSS
SECTION OF THETA-E FROM THE SOUTHERN PLAINS TO GREAT LAKES ALSO
INDICATES VERY LOW STABILITY IN THE LOW TO MID LEVELS WHICH FAVORS
MODEL SOLUTIONS THAT OFFER A DEEPER SURFACE LOW OR ARE TRENDING
DEEPER WITH THE LOW OVER IOWA WEDNESDAY NIGHT WITH A WEAKER SURFACE
REFLECTION OF THE NORTHERN STREAM WAVE OVER THE NORTHERN GREAT
LAKES. THIS SETS THE STAGE FOR A GREATER AMOUNT OF WARM AIR BEING
DRAWN NORTHWARD FROM THE PLAINS INTO THE MID LEVELS OVER THE GREAT
LAKES AS PRECIPITATION DEVELOPS TOWARD THURSDAY MORNING.

THE 12 HR LIQUID EQUIVALENT QPF IS PUSHING 0.3 INCH IN THE GFS AND
CANADIAN SOLUTIONS FOR THURSDAY WHICH REPRESENTS THE POTENTIAL FOR A
STRONGER SOLUTION ON THE SYSTEM AND A GREATER INFLUENCE OF WET BULB
COOLING ON P-TYPE AT THE ONSET. IT ALSO STILL SUPPORTS A 3 INCH
ACCUMULATION ON THE UPPER END SINCE A SNOW RATIO CLOSER TO OR EVEN
SUB 10:1 IS MORE LIKELY IN THE WARM THERMAL PROFILE. MODEL SOUNDINGS
FROM THE 12Z RUNS AND 09Z SREF MEAN INDICATE ENOUGH DRY AIR IN THE
LOW LEVELS TO LEAN TOWARD SLOWER ONSET TIMING...BUT STILL STARTING
BEFORE SUNRISE...DURING THE MORNING DRIVE...AND IN THE FORM OF SNOW.
A STRONG SOUTHERLY LOW LEVEL JET AVERAGING 45 KNOTS IN THE 900-850
MB LAYER THEN SHOWS POTENTIAL TO QUICKLY DRIVE ENOUGH WARM AIR
NORTHWARD TO OVERWHELM WET BULB EFFECTS AND CHANGE TYPE OVER TO
FREEZING RAIN UP TO ABOUT THE M-59 CORRIDOR. THE AVAILABILITY OF
WARM AIR LOOKS MORE THAN SOLID IN OBSERVATIONS TODAY OVER THE
SOUTHERN PLAINS IN SUPPORT OF A STRONG SURFACE WARM FRONT IN MODEL
DEPICTIONS. AT THE SAME TIME...SUB FREEZING SURFACE AIR WILL BE
ENTRENCHED NORTH OF THE FRONT OVER SE MICHIGAN...SCOURED OUT BRIEFLY
AROUND NOON...AND THEN WARMER AIR WILL BE SWEPT EASTWARD AS THE
SYSTEM OCCLUDES DURING THE AFTERNOON. THIS WILL CHANGE REMAINING
PRECIP BACK OVER TO SNOW BEFORE ENDING THURSDAY EVENING.

DEPARTING TROUGH WILL BE REPLACED BY SLIGHT UPPER LEVEL RIDGING
FRIDAY INTO THE START OF THE WEEKEND.  THE NEW MONTH WILL START OUT
WITH BELOW NORMAL TEMPERATURES...ALONG WITH PERIODS OF ACTIVE
WEATHER.  THINGS WILL THEN CHANGE AS ANOTHER TROUGH DIGS DOWN ACROSS
THE GREAT LAKES COME SUNDAY AS AN AREA OF LOW PRESSURE DEVELOPS
ACROSS THE SOUTH AND MOVES NORTHEAST TOWARDS THE AREA.  THIS SYSTEM
HAS THE POTENTIAL TO BRING SNOW TO THE SOUTHEAST MICHIGAN DEPENDING
ON THE OVERALL TRACK.

MARINE...

HIGH PRESSURE WILL GRADUALLY SHIFT ACROSS THE GREAT LAKES TONIGHT
THROUGH WEDNESDAY MORNING GIVING WAY TO THE NEXT WAVE OF LOW
PRESSURE ARRIVING OVER THE MIDWEST BY WEDNESDAY NIGHT. LAKE HURON
AND LOWER MICHIGAN WILL BE IN BETWEEN THE TWO SYSTEMS WHICH WILL
PRODUCE AN UPTICK IN SOUTHERLY WINDS, BUT GUSTINESS WILL BE LIMITED
TO LESS THAN 30 KNOTS DUE TO WARM STABLE AIR MOVING IN FROM THE
SOUTH. THIS WILL CHANGE BY THURSDAY NIGHT AS COLD AND STRONG
NORTHWEST WIND WILL DEVELOP AS THE LOW EXITS THE GREAT LAKES. A GALE
WATCH IS NOW IN EFFECT FOR POTENTIAL 40 KNOT GUSTS THROUGH FRIDAY
MORNING. LOWER WIND SPEED IS EXPECTED HEADING INTO THE WEEKEND BUT A
RENEWED STRETCH OF ACTIVE MARINE WEATHER IS ANTICIPATED INTO NEXT
WEEK AS MULTIPLE BOUTS OF ARCTIC AIR TRAVERSE THE WATERS.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR
     LHZ361>363-462>464.

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

$$

AVIATION.....KURIMSKI
SHORT TERM...DRK
LONG TERM....BT/SS
MARINE.......BT


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




000
FXUS63 KDTX 272322
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
622 PM EST TUE JAN 27 2015


.AVIATION...

PRIMARILY VFR CONDITIONS THROUGH THE TAF CYCLE AS AN AREA OF HIGH
PRESSURE SLIDES THROUGH THE REGION. WINDS WILL BE LIGHT AND VARIABLE
OVERNIGHT...BECOMING SOUTHERLY WEDNESDAY AFTERNOON AS THE HIGH
SLIDES OFF TO THE EAST.

//DTW THRESHOLD PROBABILITIES...

* NONE.

&&

.PREV DISCUSSION...ISSUED 353 PM EST TUE JAN 27 2015

SHORT TERM...THROUGH TONIGHT

QUIET STRETCH OF WEATHER TAKING US THROUGH TONIGHT AS HIGH PRESSURE
CENTERED OVER QUEBEC AND EASTERN ONTARIO DROPS SOUTHWARD THROUGH THE
GREAT LAKES. THE RESULTANT NORTHERLY FLOW WILL USHERS AN
INCREASINGLY DRIER AIRMASS INTO THE STATE. NE FLOW EARLIER IN THE
DAY UTILIZED LAKE HURON MOISTURE TO PRODUCE SOME LAKE EFFECT CLOUDS
OVER MUCH OF THE THUMB BUT AS WINDS TURN MORE NORTHERLY...DRIER AIR
IS ADVECTING INTO THE REGION WHICH IS ERODING THE CURRENT CLOUD
FIELD. THIS WILL HELP EXPEDITE THE PROCESS OF CLEARING THE SKIES OUT
THIS EVENING. WITH THE CLEARING SKIES...DRY AIRMASS AND CALM WINDS
WITH THE SFC HIGH...WE CAN EXPECT ANOTHER NIGHT OF FAVORABLE
RADIATIONAL COOLING. EVEN THOUGHT MID LEVEL HEIGHTS WILL BE ON THE
RISE WITH TEMPS SLOWLY CLIMBING IN THE 900-500MB LAYER...THE BL WILL
REMAIN DECOUPLED AND TEMPS WILL FALL INTO THE SINGLE DIGITS...SOME
10 DEGREES BELOW NORMAL.

LONG TERM...

SURFACE HIGH PRESSURE LINGERING OVER THE REGION WEDNESDAY WILL
ENSURE ONE MORE QUIET WEATHER DAY IN SE MICHIGAN. QUICKLY THICKENING
HIGH CLOUDS DURING THE AFTERNOON WILL BE THE FIRST SIGN OF THE NEXT
LOW PRESSURE SYSTEM SET TO MOVE INTO THE GREAT LAKES THURSDAY WHICH
IS STILL ON TRACK TO BRING A ROUND OF SNOW TO OUR AREA BUT ALSO AT
LEAST A SHORT PERIOD OF MIXED PRECIPITATION FROM THE OHIO BORDER UP
THROUGH THE NORTHERN SUBURBS OF DETROIT. TOTAL ACCUMULATION IN THE 1
TO 3 INCH RANGE REMAINS ON TARGET FOR NOW WITH THE HIGHER END OF THE
RANGE MORE LIKELY IN THE NORTHERN THUMB AND THE LOW END TOWARD THE
OHIO BORDER WHERE A MIX WILL BE A LIMITING FACTOR.

AFTERNOON SATELLITE IMAGERY INDICATES THE UPPER WAVE OVER THE GREAT
BASIN IS BEING PICKED UP BY THE NORTHERN STREAM AND IN GOOD POSITION
TO LATCH ON TO THE ENTRANCE REGION OF THE UPPER JET INTO THE CENTRAL
PLAINS WEDNESDAY. CLOSE BEHIND IS THE NORTHERN STREAM WAVE MOVING
INLAND FROM THE PACIFIC COAST OF CANADA BOTH OF WHICH WILL GET A
BROAD AREA OF SURFACE LOW PRESSURE DEVELOPMENT UNDERWAY OVER THE
PLAINS. THE PRIMARY SURFACE WAVE WILL BE EMBEDDED WITHIN THE STRONG
LOW LEVEL BAROCLINIC ZONE SET UP FROM THE DAKOTAS INTO THE TENNESSEE
VALLEY BY WEDNESDAY AFTERNOON. ASSUMING SUFFICIENT SEPARATION IS
MAINTAINED...A MODEST COUPLED JET STRUCTURE ALOFT WILL AID IN
CONTINUED DEVELOPMENT OF THE LEAD WAVE AND SURFACE LOW. A CROSS
SECTION OF THETA-E FROM THE SOUTHERN PLAINS TO GREAT LAKES ALSO
INDICATES VERY LOW STABILITY IN THE LOW TO MID LEVELS WHICH FAVORS
MODEL SOLUTIONS THAT OFFER A DEEPER SURFACE LOW OR ARE TRENDING
DEEPER WITH THE LOW OVER IOWA WEDNESDAY NIGHT WITH A WEAKER SURFACE
REFLECTION OF THE NORTHERN STREAM WAVE OVER THE NORTHERN GREAT
LAKES. THIS SETS THE STAGE FOR A GREATER AMOUNT OF WARM AIR BEING
DRAWN NORTHWARD FROM THE PLAINS INTO THE MID LEVELS OVER THE GREAT
LAKES AS PRECIPITATION DEVELOPS TOWARD THURSDAY MORNING.

THE 12 HR LIQUID EQUIVALENT QPF IS PUSHING 0.3 INCH IN THE GFS AND
CANADIAN SOLUTIONS FOR THURSDAY WHICH REPRESENTS THE POTENTIAL FOR A
STRONGER SOLUTION ON THE SYSTEM AND A GREATER INFLUENCE OF WET BULB
COOLING ON P-TYPE AT THE ONSET. IT ALSO STILL SUPPORTS A 3 INCH
ACCUMULATION ON THE UPPER END SINCE A SNOW RATIO CLOSER TO OR EVEN
SUB 10:1 IS MORE LIKELY IN THE WARM THERMAL PROFILE. MODEL SOUNDINGS
FROM THE 12Z RUNS AND 09Z SREF MEAN INDICATE ENOUGH DRY AIR IN THE
LOW LEVELS TO LEAN TOWARD SLOWER ONSET TIMING...BUT STILL STARTING
BEFORE SUNRISE...DURING THE MORNING DRIVE...AND IN THE FORM OF SNOW.
A STRONG SOUTHERLY LOW LEVEL JET AVERAGING 45 KNOTS IN THE 900-850
MB LAYER THEN SHOWS POTENTIAL TO QUICKLY DRIVE ENOUGH WARM AIR
NORTHWARD TO OVERWHELM WET BULB EFFECTS AND CHANGE TYPE OVER TO
FREEZING RAIN UP TO ABOUT THE M-59 CORRIDOR. THE AVAILABILITY OF
WARM AIR LOOKS MORE THAN SOLID IN OBSERVATIONS TODAY OVER THE
SOUTHERN PLAINS IN SUPPORT OF A STRONG SURFACE WARM FRONT IN MODEL
DEPICTIONS. AT THE SAME TIME...SUB FREEZING SURFACE AIR WILL BE
ENTRENCHED NORTH OF THE FRONT OVER SE MICHIGAN...SCOURED OUT BRIEFLY
AROUND NOON...AND THEN WARMER AIR WILL BE SWEPT EASTWARD AS THE
SYSTEM OCCLUDES DURING THE AFTERNOON. THIS WILL CHANGE REMAINING
PRECIP BACK OVER TO SNOW BEFORE ENDING THURSDAY EVENING.

DEPARTING TROUGH WILL BE REPLACED BY SLIGHT UPPER LEVEL RIDGING
FRIDAY INTO THE START OF THE WEEKEND.  THE NEW MONTH WILL START OUT
WITH BELOW NORMAL TEMPERATURES...ALONG WITH PERIODS OF ACTIVE
WEATHER.  THINGS WILL THEN CHANGE AS ANOTHER TROUGH DIGS DOWN ACROSS
THE GREAT LAKES COME SUNDAY AS AN AREA OF LOW PRESSURE DEVELOPS
ACROSS THE SOUTH AND MOVES NORTHEAST TOWARDS THE AREA.  THIS SYSTEM
HAS THE POTENTIAL TO BRING SNOW TO THE SOUTHEAST MICHIGAN DEPENDING
ON THE OVERALL TRACK.

MARINE...

HIGH PRESSURE WILL GRADUALLY SHIFT ACROSS THE GREAT LAKES TONIGHT
THROUGH WEDNESDAY MORNING GIVING WAY TO THE NEXT WAVE OF LOW
PRESSURE ARRIVING OVER THE MIDWEST BY WEDNESDAY NIGHT. LAKE HURON
AND LOWER MICHIGAN WILL BE IN BETWEEN THE TWO SYSTEMS WHICH WILL
PRODUCE AN UPTICK IN SOUTHERLY WINDS, BUT GUSTINESS WILL BE LIMITED
TO LESS THAN 30 KNOTS DUE TO WARM STABLE AIR MOVING IN FROM THE
SOUTH. THIS WILL CHANGE BY THURSDAY NIGHT AS COLD AND STRONG
NORTHWEST WIND WILL DEVELOP AS THE LOW EXITS THE GREAT LAKES. A GALE
WATCH IS NOW IN EFFECT FOR POTENTIAL 40 KNOT GUSTS THROUGH FRIDAY
MORNING. LOWER WIND SPEED IS EXPECTED HEADING INTO THE WEEKEND BUT A
RENEWED STRETCH OF ACTIVE MARINE WEATHER IS ANTICIPATED INTO NEXT
WEEK AS MULTIPLE BOUTS OF ARCTIC AIR TRAVERSE THE WATERS.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR
     LHZ361>363-462>464.

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

$$

AVIATION.....KURIMSKI
SHORT TERM...DRK
LONG TERM....BT/SS
MARINE.......BT


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





000
FXUS63 KDTX 272053
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
353 PM EST TUE JAN 27 2015

.SHORT TERM...THROUGH TONIGHT

QUIET STRETCH OF WEATHER TAKING US THROUGH TONIGHT AS HIGH PRESSURE
CENTERED OVER QUEBEC AND EASTERN ONTARIO DROPS SOUTHWARD THROUGH THE
GREAT LAKES. THE RESULTANT NORTHERLY FLOW WILL USHERS AN
INCREASINGLY DRIER AIRMASS INTO THE STATE. NE FLOW EARLIER IN THE
DAY UTILIZED LAKE HURON MOISTURE TO PRODUCE SOME LAKE EFFECT CLOUDS
OVER MUCH OF THE THUMB BUT AS WINDS TURN MORE NORTHERLY...DRIER AIR
IS ADVECTING INTO THE REGION WHICH IS ERODING THE CURRENT CLOUD
FIELD. THIS WILL HELP EXPEDITE THE PROCESS OF CLEARING THE SKIES OUT
THIS EVENING. WITH THE CLEARING SKIES...DRY AIRMASS AND CALM WINDS
WITH THE SFC HIGH...WE CAN EXPECT ANOTHER NIGHT OF FAVORABLE
RADIATIONAL COOLING. EVEN THOUGHT MID LEVEL HEIGHTS WILL BE ON THE
RISE WITH TEMPS SLOWLY CLIMBING IN THE 900-500MB LAYER...THE BL WILL
REMAIN DECOUPLED AND TEMPS WILL FALL INTO THE SINGLE DIGITS...SOME
10 DEGREES BELOW NORMAL.

&&

.LONG TERM...

SURFACE HIGH PRESSURE LINGERING OVER THE REGION WEDNESDAY WILL
ENSURE ONE MORE QUIET WEATHER DAY IN SE MICHIGAN. QUICKLY THICKENING
HIGH CLOUDS DURING THE AFTERNOON WILL BE THE FIRST SIGN OF THE NEXT
LOW PRESSURE SYSTEM SET TO MOVE INTO THE GREAT LAKES THURSDAY WHICH
IS STILL ON TRACK TO BRING A ROUND OF SNOW TO OUR AREA BUT ALSO AT
LEAST A SHORT PERIOD OF MIXED PRECIPITATION FROM THE OHIO BORDER UP
THROUGH THE NORTHERN SUBURBS OF DETROIT. TOTAL ACCUMULATION IN THE 1
TO 3 INCH RANGE REMAINS ON TARGET FOR NOW WITH THE HIGHER END OF THE
RANGE MORE LIKELY IN THE NORTHERN THUMB AND THE LOW END TOWARD THE
OHIO BORDER WHERE A MIX WILL BE A LIMITING FACTOR.

AFTERNOON SATELLITE IMAGERY INDICATES THE UPPER WAVE OVER THE GREAT
BASIN IS BEING PICKED UP BY THE NORTHERN STREAM AND IN GOOD POSITION
TO LATCH ON TO THE ENTRANCE REGION OF THE UPPER JET INTO THE CENTRAL
PLAINS WEDNESDAY. CLOSE BEHIND IS THE NORTHERN STREAM WAVE MOVING
INLAND FROM THE PACIFIC COAST OF CANADA BOTH OF WHICH WILL GET A
BROAD AREA OF SURFACE LOW PRESSURE DEVELOPMENT UNDERWAY OVER THE
PLAINS. THE PRIMARY SURFACE WAVE WILL BE EMBEDDED WITHIN THE STRONG
LOW LEVEL BAROCLINIC ZONE SET UP FROM THE DAKOTAS INTO THE TENNESSEE
VALLEY BY WEDNESDAY AFTERNOON. ASSUMING SUFFICIENT SEPARATION IS
MAINTAINED...A MODEST COUPLED JET STRUCTURE ALOFT WILL AID IN
CONTINUED DEVELOPMENT OF THE LEAD WAVE AND SURFACE LOW. A CROSS
SECTION OF THETA-E FROM THE SOUTHERN PLAINS TO GREAT LAKES ALSO
INDICATES VERY LOW STABILITY IN THE LOW TO MID LEVELS WHICH FAVORS
MODEL SOLUTIONS THAT OFFER A DEEPER SURFACE LOW OR ARE TRENDING
DEEPER WITH THE LOW OVER IOWA WEDNESDAY NIGHT WITH A WEAKER SURFACE
REFLECTION OF THE NORTHERN STREAM WAVE OVER THE NORTHERN GREAT
LAKES. THIS SETS THE STAGE FOR A GREATER AMOUNT OF WARM AIR BEING
DRAWN NORTHWARD FROM THE PLAINS INTO THE MID LEVELS OVER THE GREAT
LAKES AS PRECIPITATION DEVELOPS TOWARD THURSDAY MORNING.

THE 12 HR LIQUID EQUIVALENT QPF IS PUSHING 0.3 INCH IN THE GFS AND
CANADIAN SOLUTIONS FOR THURSDAY WHICH REPRESENTS THE POTENTIAL FOR A
STRONGER SOLUTION ON THE SYSTEM AND A GREATER INFLUENCE OF WET BULB
COOLING ON P-TYPE AT THE ONSET. IT ALSO STILL SUPPORTS A 3 INCH
ACCUMULATION ON THE UPPER END SINCE A SNOW RATIO CLOSER TO OR EVEN
SUB 10:1 IS MORE LIKELY IN THE WARM THERMAL PROFILE. MODEL SOUNDINGS
FROM THE 12Z RUNS AND 09Z SREF MEAN INDICATE ENOUGH DRY AIR IN THE
LOW LEVELS TO LEAN TOWARD SLOWER ONSET TIMING...BUT STILL STARTING
BEFORE SUNRISE...DURING THE MORNING DRIVE...AND IN THE FORM OF SNOW.
A STRONG SOUTHERLY LOW LEVEL JET AVERAGING 45 KNOTS IN THE 900-850
MB LAYER THEN SHOWS POTENTIAL TO QUICKLY DRIVE ENOUGH WARM AIR
NORTHWARD TO OVERWHELM WET BULB EFFECTS AND CHANGE TYPE OVER TO
FREEZING RAIN UP TO ABOUT THE M-59 CORRIDOR. THE AVAILABILITY OF
WARM AIR LOOKS MORE THAN SOLID IN OBSERVATIONS TODAY OVER THE
SOUTHERN PLAINS IN SUPPORT OF A STRONG SURFACE WARM FRONT IN MODEL
DEPICTIONS. AT THE SAME TIME...SUB FREEZING SURFACE AIR WILL BE
ENTRENCHED NORTH OF THE FRONT OVER SE MICHIGAN...SCOURED OUT BRIEFLY
AROUND NOON...AND THEN WARMER AIR WILL BE SWEPT EASTWARD AS THE
SYSTEM OCCLUDES DURING THE AFTERNOON. THIS WILL CHANGE REMAINING
PRECIP BACK OVER TO SNOW BEFORE ENDING THURSDAY EVENING.

DEPARTING TROUGH WILL BE REPLACED BY SLIGHT UPPER LEVEL RIDGING
FRIDAY INTO THE START OF THE WEEKEND.  THE NEW MONTH WILL START OUT
WITH BELOW NORMAL TEMPERATURES...ALONG WITH PERIODS OF ACTIVE
WEATHER.  THINGS WILL THEN CHANGE AS ANOTHER TROUGH DIGS DOWN ACROSS
THE GREAT LAKES COME SUNDAY AS AN AREA OF LOW PRESSURE DEVELOPS
ACROSS THE SOUTH AND MOVES NORTHEAST TOWARDS THE AREA.  THIS SYSTEM
HAS THE POTENTIAL TO BRING SNOW TO THE SOUTHEAST MICHIGAN DEPENDING
ON THE OVERALL TRACK.

&&

.MARINE...

HIGH PRESSURE WILL GRADUALLY SHIFT ACROSS THE GREAT LAKES TONIGHT
THROUGH WEDNESDAY MORNING GIVING WAY TO THE NEXT WAVE OF LOW
PRESSURE ARRIVING OVER THE MIDWEST BY WEDNESDAY NIGHT. LAKE HURON
AND LOWER MICHIGAN WILL BE IN BETWEEN THE TWO SYSTEMS WHICH WILL
PRODUCE AN UPTICK IN SOUTHERLY WINDS, BUT GUSTINESS WILL BE LIMITED
TO LESS THAN 30 KNOTS DUE TO WARM STABLE AIR MOVING IN FROM THE
SOUTH. THIS WILL CHANGE BY THURSDAY NIGHT AS COLD AND STRONG
NORTHWEST WIND WILL DEVELOP AS THE LOW EXITS THE GREAT LAKES. A GALE
WATCH IS NOW IN EFFECT FOR POTENTIAL 40 KNOT GUSTS THROUGH FRIDAY
MORNING. LOWER WIND SPEED IS EXPECTED HEADING INTO THE WEEKEND BUT A
RENEWED STRETCH OF ACTIVE MARINE WEATHER IS ANTICIPATED INTO NEXT
WEEK AS MULTIPLE BOUTS OF ARCTIC AIR TRAVERSE THE WATERS.

&&

.AVIATION...ISSUED 1234 PM EST TUE JAN 27 2015

PRIMARILY VFR CONDITIONS THROUGH THE TAF CYCLE AS AN AREA OF HIGH
PRESSURE SLIDES THROUGH THE REGION. THE ONE CONCERN FOR THIS
AFTERNOON IS MOISTURE ADVECTING INLAND OFF LAKE HURON LEADING TO
POCKETS OF MVFR LAKE EFFECT STRATO-CU. THE DRY AIR HAS MADE IT
DIFFICULT TO SUSTAIN THE CLOUDS TOO FAR INLAND BUT DID INCLUDE A
MVFR TEMPO GROUP FOR MBS AND FNT FOR A FEW HOURS TO ACCOUNT FOR
THICKER CLOUD COVER IN THAT AREA. AFTERNOON WINDS WILL DECREASE THIS
EVENING...BECOME LIGHT AND VARIABLE OVERNIGHT.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CEILING BELOW 5000 FT TODAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR
     LHZ361>363-462>464.

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

$$

SHORT TERM...DRK
LONG TERM....BT/SS
MARINE.......BT
AVIATION.....DRK


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




000
FXUS63 KDTX 272053
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
353 PM EST TUE JAN 27 2015

.SHORT TERM...THROUGH TONIGHT

QUIET STRETCH OF WEATHER TAKING US THROUGH TONIGHT AS HIGH PRESSURE
CENTERED OVER QUEBEC AND EASTERN ONTARIO DROPS SOUTHWARD THROUGH THE
GREAT LAKES. THE RESULTANT NORTHERLY FLOW WILL USHERS AN
INCREASINGLY DRIER AIRMASS INTO THE STATE. NE FLOW EARLIER IN THE
DAY UTILIZED LAKE HURON MOISTURE TO PRODUCE SOME LAKE EFFECT CLOUDS
OVER MUCH OF THE THUMB BUT AS WINDS TURN MORE NORTHERLY...DRIER AIR
IS ADVECTING INTO THE REGION WHICH IS ERODING THE CURRENT CLOUD
FIELD. THIS WILL HELP EXPEDITE THE PROCESS OF CLEARING THE SKIES OUT
THIS EVENING. WITH THE CLEARING SKIES...DRY AIRMASS AND CALM WINDS
WITH THE SFC HIGH...WE CAN EXPECT ANOTHER NIGHT OF FAVORABLE
RADIATIONAL COOLING. EVEN THOUGHT MID LEVEL HEIGHTS WILL BE ON THE
RISE WITH TEMPS SLOWLY CLIMBING IN THE 900-500MB LAYER...THE BL WILL
REMAIN DECOUPLED AND TEMPS WILL FALL INTO THE SINGLE DIGITS...SOME
10 DEGREES BELOW NORMAL.

&&

.LONG TERM...

SURFACE HIGH PRESSURE LINGERING OVER THE REGION WEDNESDAY WILL
ENSURE ONE MORE QUIET WEATHER DAY IN SE MICHIGAN. QUICKLY THICKENING
HIGH CLOUDS DURING THE AFTERNOON WILL BE THE FIRST SIGN OF THE NEXT
LOW PRESSURE SYSTEM SET TO MOVE INTO THE GREAT LAKES THURSDAY WHICH
IS STILL ON TRACK TO BRING A ROUND OF SNOW TO OUR AREA BUT ALSO AT
LEAST A SHORT PERIOD OF MIXED PRECIPITATION FROM THE OHIO BORDER UP
THROUGH THE NORTHERN SUBURBS OF DETROIT. TOTAL ACCUMULATION IN THE 1
TO 3 INCH RANGE REMAINS ON TARGET FOR NOW WITH THE HIGHER END OF THE
RANGE MORE LIKELY IN THE NORTHERN THUMB AND THE LOW END TOWARD THE
OHIO BORDER WHERE A MIX WILL BE A LIMITING FACTOR.

AFTERNOON SATELLITE IMAGERY INDICATES THE UPPER WAVE OVER THE GREAT
BASIN IS BEING PICKED UP BY THE NORTHERN STREAM AND IN GOOD POSITION
TO LATCH ON TO THE ENTRANCE REGION OF THE UPPER JET INTO THE CENTRAL
PLAINS WEDNESDAY. CLOSE BEHIND IS THE NORTHERN STREAM WAVE MOVING
INLAND FROM THE PACIFIC COAST OF CANADA BOTH OF WHICH WILL GET A
BROAD AREA OF SURFACE LOW PRESSURE DEVELOPMENT UNDERWAY OVER THE
PLAINS. THE PRIMARY SURFACE WAVE WILL BE EMBEDDED WITHIN THE STRONG
LOW LEVEL BAROCLINIC ZONE SET UP FROM THE DAKOTAS INTO THE TENNESSEE
VALLEY BY WEDNESDAY AFTERNOON. ASSUMING SUFFICIENT SEPARATION IS
MAINTAINED...A MODEST COUPLED JET STRUCTURE ALOFT WILL AID IN
CONTINUED DEVELOPMENT OF THE LEAD WAVE AND SURFACE LOW. A CROSS
SECTION OF THETA-E FROM THE SOUTHERN PLAINS TO GREAT LAKES ALSO
INDICATES VERY LOW STABILITY IN THE LOW TO MID LEVELS WHICH FAVORS
MODEL SOLUTIONS THAT OFFER A DEEPER SURFACE LOW OR ARE TRENDING
DEEPER WITH THE LOW OVER IOWA WEDNESDAY NIGHT WITH A WEAKER SURFACE
REFLECTION OF THE NORTHERN STREAM WAVE OVER THE NORTHERN GREAT
LAKES. THIS SETS THE STAGE FOR A GREATER AMOUNT OF WARM AIR BEING
DRAWN NORTHWARD FROM THE PLAINS INTO THE MID LEVELS OVER THE GREAT
LAKES AS PRECIPITATION DEVELOPS TOWARD THURSDAY MORNING.

THE 12 HR LIQUID EQUIVALENT QPF IS PUSHING 0.3 INCH IN THE GFS AND
CANADIAN SOLUTIONS FOR THURSDAY WHICH REPRESENTS THE POTENTIAL FOR A
STRONGER SOLUTION ON THE SYSTEM AND A GREATER INFLUENCE OF WET BULB
COOLING ON P-TYPE AT THE ONSET. IT ALSO STILL SUPPORTS A 3 INCH
ACCUMULATION ON THE UPPER END SINCE A SNOW RATIO CLOSER TO OR EVEN
SUB 10:1 IS MORE LIKELY IN THE WARM THERMAL PROFILE. MODEL SOUNDINGS
FROM THE 12Z RUNS AND 09Z SREF MEAN INDICATE ENOUGH DRY AIR IN THE
LOW LEVELS TO LEAN TOWARD SLOWER ONSET TIMING...BUT STILL STARTING
BEFORE SUNRISE...DURING THE MORNING DRIVE...AND IN THE FORM OF SNOW.
A STRONG SOUTHERLY LOW LEVEL JET AVERAGING 45 KNOTS IN THE 900-850
MB LAYER THEN SHOWS POTENTIAL TO QUICKLY DRIVE ENOUGH WARM AIR
NORTHWARD TO OVERWHELM WET BULB EFFECTS AND CHANGE TYPE OVER TO
FREEZING RAIN UP TO ABOUT THE M-59 CORRIDOR. THE AVAILABILITY OF
WARM AIR LOOKS MORE THAN SOLID IN OBSERVATIONS TODAY OVER THE
SOUTHERN PLAINS IN SUPPORT OF A STRONG SURFACE WARM FRONT IN MODEL
DEPICTIONS. AT THE SAME TIME...SUB FREEZING SURFACE AIR WILL BE
ENTRENCHED NORTH OF THE FRONT OVER SE MICHIGAN...SCOURED OUT BRIEFLY
AROUND NOON...AND THEN WARMER AIR WILL BE SWEPT EASTWARD AS THE
SYSTEM OCCLUDES DURING THE AFTERNOON. THIS WILL CHANGE REMAINING
PRECIP BACK OVER TO SNOW BEFORE ENDING THURSDAY EVENING.

DEPARTING TROUGH WILL BE REPLACED BY SLIGHT UPPER LEVEL RIDGING
FRIDAY INTO THE START OF THE WEEKEND.  THE NEW MONTH WILL START OUT
WITH BELOW NORMAL TEMPERATURES...ALONG WITH PERIODS OF ACTIVE
WEATHER.  THINGS WILL THEN CHANGE AS ANOTHER TROUGH DIGS DOWN ACROSS
THE GREAT LAKES COME SUNDAY AS AN AREA OF LOW PRESSURE DEVELOPS
ACROSS THE SOUTH AND MOVES NORTHEAST TOWARDS THE AREA.  THIS SYSTEM
HAS THE POTENTIAL TO BRING SNOW TO THE SOUTHEAST MICHIGAN DEPENDING
ON THE OVERALL TRACK.

&&

.MARINE...

HIGH PRESSURE WILL GRADUALLY SHIFT ACROSS THE GREAT LAKES TONIGHT
THROUGH WEDNESDAY MORNING GIVING WAY TO THE NEXT WAVE OF LOW
PRESSURE ARRIVING OVER THE MIDWEST BY WEDNESDAY NIGHT. LAKE HURON
AND LOWER MICHIGAN WILL BE IN BETWEEN THE TWO SYSTEMS WHICH WILL
PRODUCE AN UPTICK IN SOUTHERLY WINDS, BUT GUSTINESS WILL BE LIMITED
TO LESS THAN 30 KNOTS DUE TO WARM STABLE AIR MOVING IN FROM THE
SOUTH. THIS WILL CHANGE BY THURSDAY NIGHT AS COLD AND STRONG
NORTHWEST WIND WILL DEVELOP AS THE LOW EXITS THE GREAT LAKES. A GALE
WATCH IS NOW IN EFFECT FOR POTENTIAL 40 KNOT GUSTS THROUGH FRIDAY
MORNING. LOWER WIND SPEED IS EXPECTED HEADING INTO THE WEEKEND BUT A
RENEWED STRETCH OF ACTIVE MARINE WEATHER IS ANTICIPATED INTO NEXT
WEEK AS MULTIPLE BOUTS OF ARCTIC AIR TRAVERSE THE WATERS.

&&

.AVIATION...ISSUED 1234 PM EST TUE JAN 27 2015

PRIMARILY VFR CONDITIONS THROUGH THE TAF CYCLE AS AN AREA OF HIGH
PRESSURE SLIDES THROUGH THE REGION. THE ONE CONCERN FOR THIS
AFTERNOON IS MOISTURE ADVECTING INLAND OFF LAKE HURON LEADING TO
POCKETS OF MVFR LAKE EFFECT STRATO-CU. THE DRY AIR HAS MADE IT
DIFFICULT TO SUSTAIN THE CLOUDS TOO FAR INLAND BUT DID INCLUDE A
MVFR TEMPO GROUP FOR MBS AND FNT FOR A FEW HOURS TO ACCOUNT FOR
THICKER CLOUD COVER IN THAT AREA. AFTERNOON WINDS WILL DECREASE THIS
EVENING...BECOME LIGHT AND VARIABLE OVERNIGHT.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CEILING BELOW 5000 FT TODAY.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR
     LHZ361>363-462>464.

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

$$

SHORT TERM...DRK
LONG TERM....BT/SS
MARINE.......BT
AVIATION.....DRK


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





000
FXUS63 KDTX 271734
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1234 PM EST TUE JAN 27 2015


.AVIATION...

PRIMARILY VFR CONDITIONS THROUGH THE TAF CYCLE AS AN AREA OF HIGH
PRESSURE SLIDES THROUGH THE REGION. THE ONE CONCERN FOR THIS
AFTERNOON IS MOISTURE ADVECTING INLAND OFF LAKE HURON LEADING TO
POCKETS OF MVFR LAKE EFFECT STRATO-CU. THE DRY AIR HAS MADE IT
DIFFICULT TO SUSTAIN THE CLOUDS TOO FAR INLAND BUT DID INCLUDE A
MVFR TEMPO GROUP FOR MBS AND FNT FOR A FEW HOURS TO ACCOUNT FOR
THICKER CLOUD COVER IN THAT AREA. AFTERNOON WINDS WILL DECREASE THIS
EVENING...BECOME LIGHT AND VARIABLE OVERNIGHT.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CEILING BELOW 5000 FT TODAY.

&&

.PREV DISCUSSION...ISSUED 253 AM EST TUE JAN 27 2015

SHORT TERM...TODAY AND TONIGHT

COLD...BUT QUIET...WEATHER WILL CONTINUE OVER THE AREA AS HIGH
PRESSURE SETTLES SOUTH INTO THE AREA ON BACKSIDE OF MAJOR STORM
LIFTING UP THE NORTHEAST COAST. INITIALLY...EXPECT PARTLY TO MOSTLY
CLOUDY SKIES TODAY AS BOTH STRATUS/STRATO-CU FROM LAKE HURON AND A
MID LEVEL DECK ASSOCIATED WITH A SHORTWAVE COMBINE TO BRING SOME
DEGREE OF CLOUDINESS TO A GOOD PORTION OF THE AREA. TEMPERATURES
WILL REMAIN BELOW AVERAGE AS HIGHS ONLY CLIMB INTO THE LOWER TO
MIDDLE 20S BY AFTERNOON.

AS THE AFOREMENTIONED HIGH SETTLE OVER AND THEN JUST SOUTH OF THE
AREA THIS EVENING INTO TONIGHT...SKIES WILL LARGELY CLEAR. THIS WILL
COMBINE WITH LIGHT WINDS ASSOCIATED WITH THE HIGH TO PRODUCE RATHER
DECENT RADIATIONAL COOLING. SO...EXPECT WIDESPREAD LOW TEMPERATURES
IN THE SINGLE DIGITS...SOME 8 TO 10 DEGREES BELOW AVERAGE FOR LATE
JANUARY.

LONG TERM...

SHORTWAVE ANCHORING NORTHERN SEGMENT OF THE EAST PAC TROUGH WILL
COME ONSHORE IN BRITISH COLUMBIA OVER THE NEXT 18 HOURS. THE BAJA
LOW HAS SIMTULTANEOUSLY BEGUN TO OPEN UP AND HELP ERODE THE RIDGE
POSITIONED OVER THE WESTERN UNITED STATES. THE SURFACE LOW ATTENDANT
TO THE LEAD SHORTWAVE WILL HELP ENHANCE DEVELOPING SOUTHEAST RETURN
FLOW ON WEDNESDAY, ALLOWING HIGHS TO WARM SEVERAL DEGREES OVER
TODAY. FORECAST SOUNDINGS ARE ONLY MARGINALLY SUPPORTIVE OF DIURNAL
STRATOCU DEVELOPMENT BENEATH THE STOUT DRY SUBSIDENT LAYER ALOFT, SO
ELECTED TO REMAIN CONSERVATIVE WITH CLOUD COVER ON WED. AFTERNOON
HIGHS SHOULD REACH CLOSE TO 30 DEGREES IN MOST SPOTS UNDER PARTLY
CLOUDY SKIES.

PRECIPITATION WILL BLOSSOM JUST UPSTREAM OF THE AREA WEDNESDAY NIGHT
INTO THURSDAY AS HEIGHT FALLS SPREAD INTO THE REGION AND ISENTROPIC
ASCENT SUPPORTED BY A STRENGTHENING LOW-LEVEL JET RAMPS UP. THE
GFS/GEM HAVE TRENDED TOWARD PRIOR ECMWF SOLUTIONS IN THAT THEIR MORE
AGGRESSIVE DEPICTIONS OF THE TRAILING SHORTWAVE RESULT IN A QUICK
NORTHWARD TRANSITION OF THE SURFACE LOW PRESSURE CENTER OVER THE
AREA. THIS IS BOTH A WARMER SCENARIO AND WEAKER FOR SOUTHEAST
MICHIGAN IN TERMS OF MESOSCALE FORCING DUE TO LOCAL POSITION WRT THE
SURFACE LOW. THE 00Z ECMWF HAS CHANGED CONSIDERABLY AS IT MODELS
BOTH WAVES WEAKER AND IS CONSIDERABLY STRONGER WITH ITS DEPICTIONS
OF HIGH-LATITUDE ENERGY DIGGING INTO THE GREAT LAKES IMMEDIATELY
BEHIND THE CLIPPER. THIS RESULTS IN A PERIOD OF RATHER BROAD/POORLY
FOCUSED MID-LEVEL FORCING AND A TENDENCY TOWARD A BROAD OPEN SURFACE
WAVE TRANSLATING ACROSS THE AREA ON THURSDAY AFTERNOON. MOVING
FORWARD WITH A GENERAL 1-3" IS STILL PRUDENT AT THIS STAGE AS IT
SEEMS LIKE WE WILL GET THERE ONE WAY OR ANOTHER. ALSO INTRODUCED A
CHANCE OF RAIN FOR THE SOUTHERN TWO TIERS OF COUNTIES ON THURSDAY
AFTN WHERE AMOUNTS ARE MORE LIKELY TO BE AN INCH OR LESS. COLD AIR
WILL FILL IN BEHIND THE CLIPPER DROPPING THURSDAY NIGHT LOWS BACK
INTO THE 10-15F RANGE.

MARINE...

LIGHT TO MODERATE WINDS WILL PERSIST THROUGH THURSDAY AS THE
GRADIENT RELAXES DUE TO RESIDENT HIGH PRESSURE. AN APPROACHING WEAK
LOW PRESSURE WEDNESDAY NIGHT THROUGH THURSDAY WILL CAUSE AN UPTICK
IN SOUTHERLY WINDS, BUT GUSTINESS WILL BE LIMITED TO AROUND 25 KNOTS
DUE TO WARM STABLE FLOW FROM THE SOUTH. COLD AIR MOVING INTO THE
GREAT LAKES IN THE WAKE OF THIS SYSTEM WILL MARK THE BEGINNING OF A
RENEWED STRETCH OF ACTIVE MARINE WEATHER THURSDAY NIGHT INTO NEXT
WEEK AS MULTIPLE BOUTS OF ARCTIC AIR TRAVERSE THE WATERS. THE FIRST
SUCH PERIOD OF ACTIVE WEATHER WILL BE THURSDAY NIGHT WHEN MODERATE
TO STRONG NORTHWEST GALES APPEAR POSSIBLE. THIS PERIOD WILL BE
MONITORED IN THE FOLLOWING FORECAST CYCLES FOR POTENTIAL GALE WATCH
ISSUANCE.

&&

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

$$

AVIATION.....DRK
SHORT TERM...DG
LONG TERM....JVC
MARINE.......JVC


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





000
FXUS63 KDTX 271734
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1234 PM EST TUE JAN 27 2015


.AVIATION...

PRIMARILY VFR CONDITIONS THROUGH THE TAF CYCLE AS AN AREA OF HIGH
PRESSURE SLIDES THROUGH THE REGION. THE ONE CONCERN FOR THIS
AFTERNOON IS MOISTURE ADVECTING INLAND OFF LAKE HURON LEADING TO
POCKETS OF MVFR LAKE EFFECT STRATO-CU. THE DRY AIR HAS MADE IT
DIFFICULT TO SUSTAIN THE CLOUDS TOO FAR INLAND BUT DID INCLUDE A
MVFR TEMPO GROUP FOR MBS AND FNT FOR A FEW HOURS TO ACCOUNT FOR
THICKER CLOUD COVER IN THAT AREA. AFTERNOON WINDS WILL DECREASE THIS
EVENING...BECOME LIGHT AND VARIABLE OVERNIGHT.

//DTW THRESHOLD PROBABILITIES...

* LOW FOR CEILING BELOW 5000 FT TODAY.

&&

.PREV DISCUSSION...ISSUED 253 AM EST TUE JAN 27 2015

SHORT TERM...TODAY AND TONIGHT

COLD...BUT QUIET...WEATHER WILL CONTINUE OVER THE AREA AS HIGH
PRESSURE SETTLES SOUTH INTO THE AREA ON BACKSIDE OF MAJOR STORM
LIFTING UP THE NORTHEAST COAST. INITIALLY...EXPECT PARTLY TO MOSTLY
CLOUDY SKIES TODAY AS BOTH STRATUS/STRATO-CU FROM LAKE HURON AND A
MID LEVEL DECK ASSOCIATED WITH A SHORTWAVE COMBINE TO BRING SOME
DEGREE OF CLOUDINESS TO A GOOD PORTION OF THE AREA. TEMPERATURES
WILL REMAIN BELOW AVERAGE AS HIGHS ONLY CLIMB INTO THE LOWER TO
MIDDLE 20S BY AFTERNOON.

AS THE AFOREMENTIONED HIGH SETTLE OVER AND THEN JUST SOUTH OF THE
AREA THIS EVENING INTO TONIGHT...SKIES WILL LARGELY CLEAR. THIS WILL
COMBINE WITH LIGHT WINDS ASSOCIATED WITH THE HIGH TO PRODUCE RATHER
DECENT RADIATIONAL COOLING. SO...EXPECT WIDESPREAD LOW TEMPERATURES
IN THE SINGLE DIGITS...SOME 8 TO 10 DEGREES BELOW AVERAGE FOR LATE
JANUARY.

LONG TERM...

SHORTWAVE ANCHORING NORTHERN SEGMENT OF THE EAST PAC TROUGH WILL
COME ONSHORE IN BRITISH COLUMBIA OVER THE NEXT 18 HOURS. THE BAJA
LOW HAS SIMTULTANEOUSLY BEGUN TO OPEN UP AND HELP ERODE THE RIDGE
POSITIONED OVER THE WESTERN UNITED STATES. THE SURFACE LOW ATTENDANT
TO THE LEAD SHORTWAVE WILL HELP ENHANCE DEVELOPING SOUTHEAST RETURN
FLOW ON WEDNESDAY, ALLOWING HIGHS TO WARM SEVERAL DEGREES OVER
TODAY. FORECAST SOUNDINGS ARE ONLY MARGINALLY SUPPORTIVE OF DIURNAL
STRATOCU DEVELOPMENT BENEATH THE STOUT DRY SUBSIDENT LAYER ALOFT, SO
ELECTED TO REMAIN CONSERVATIVE WITH CLOUD COVER ON WED. AFTERNOON
HIGHS SHOULD REACH CLOSE TO 30 DEGREES IN MOST SPOTS UNDER PARTLY
CLOUDY SKIES.

PRECIPITATION WILL BLOSSOM JUST UPSTREAM OF THE AREA WEDNESDAY NIGHT
INTO THURSDAY AS HEIGHT FALLS SPREAD INTO THE REGION AND ISENTROPIC
ASCENT SUPPORTED BY A STRENGTHENING LOW-LEVEL JET RAMPS UP. THE
GFS/GEM HAVE TRENDED TOWARD PRIOR ECMWF SOLUTIONS IN THAT THEIR MORE
AGGRESSIVE DEPICTIONS OF THE TRAILING SHORTWAVE RESULT IN A QUICK
NORTHWARD TRANSITION OF THE SURFACE LOW PRESSURE CENTER OVER THE
AREA. THIS IS BOTH A WARMER SCENARIO AND WEAKER FOR SOUTHEAST
MICHIGAN IN TERMS OF MESOSCALE FORCING DUE TO LOCAL POSITION WRT THE
SURFACE LOW. THE 00Z ECMWF HAS CHANGED CONSIDERABLY AS IT MODELS
BOTH WAVES WEAKER AND IS CONSIDERABLY STRONGER WITH ITS DEPICTIONS
OF HIGH-LATITUDE ENERGY DIGGING INTO THE GREAT LAKES IMMEDIATELY
BEHIND THE CLIPPER. THIS RESULTS IN A PERIOD OF RATHER BROAD/POORLY
FOCUSED MID-LEVEL FORCING AND A TENDENCY TOWARD A BROAD OPEN SURFACE
WAVE TRANSLATING ACROSS THE AREA ON THURSDAY AFTERNOON. MOVING
FORWARD WITH A GENERAL 1-3" IS STILL PRUDENT AT THIS STAGE AS IT
SEEMS LIKE WE WILL GET THERE ONE WAY OR ANOTHER. ALSO INTRODUCED A
CHANCE OF RAIN FOR THE SOUTHERN TWO TIERS OF COUNTIES ON THURSDAY
AFTN WHERE AMOUNTS ARE MORE LIKELY TO BE AN INCH OR LESS. COLD AIR
WILL FILL IN BEHIND THE CLIPPER DROPPING THURSDAY NIGHT LOWS BACK
INTO THE 10-15F RANGE.

MARINE...

LIGHT TO MODERATE WINDS WILL PERSIST THROUGH THURSDAY AS THE
GRADIENT RELAXES DUE TO RESIDENT HIGH PRESSURE. AN APPROACHING WEAK
LOW PRESSURE WEDNESDAY NIGHT THROUGH THURSDAY WILL CAUSE AN UPTICK
IN SOUTHERLY WINDS, BUT GUSTINESS WILL BE LIMITED TO AROUND 25 KNOTS
DUE TO WARM STABLE FLOW FROM THE SOUTH. COLD AIR MOVING INTO THE
GREAT LAKES IN THE WAKE OF THIS SYSTEM WILL MARK THE BEGINNING OF A
RENEWED STRETCH OF ACTIVE MARINE WEATHER THURSDAY NIGHT INTO NEXT
WEEK AS MULTIPLE BOUTS OF ARCTIC AIR TRAVERSE THE WATERS. THE FIRST
SUCH PERIOD OF ACTIVE WEATHER WILL BE THURSDAY NIGHT WHEN MODERATE
TO STRONG NORTHWEST GALES APPEAR POSSIBLE. THIS PERIOD WILL BE
MONITORED IN THE FOLLOWING FORECAST CYCLES FOR POTENTIAL GALE WATCH
ISSUANCE.

&&

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

$$

AVIATION.....DRK
SHORT TERM...DG
LONG TERM....JVC
MARINE.......JVC


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