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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


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