000
FXUS63 KDTX 050454
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1154 PM EST TUE MAR 4 2014


.AVIATION...

//DISCUSSION...

MVFR TO LOWER VFR CIGS WILL HOLD MUCH OF THE FORECAST PERIOD ALONG
THE SOUTHERN FRINGE OF HIGH PRESSURE SYSTEM AS IT BUILDS SOUTHEAST
FROM NORTHERN ONTARIO INTO QUEBEC DURING THE NEXT 24 HOURS. MBS/FNT
WILL BE FIRST TO SCATTER OUT AS DRIER NORTHEAST FLOW BLEEDS OFF OF
THIS HIGH INTO THE AREA ON WEDNESDAY. SO...WHILE OVERCAST CIGS WILL
BECOME BKN IN GENERAL...EXPECT FEW-SCT STRATO-CU BY LATE IN THE DAY
AT THESE LOCATIONS.

FOR DTW...LOW LEVEL MOISTURE WILL GRADUALLY INCREASE OVERNIGHT WITH
CIGS AOB 5KFT OVERNIGHT INTO WEDNESDAY. DRIER NORTHEAST FLOW WILL
BRING CIGS BACK ABOVE 5KFT BY WEDNESDAY AFTERNOON/EVENING.

//DTW THRESHOLD THREATS...

* HIGH CONFIDENCE IN CEILINGS AOB 5000 FEET OVERNIGHT INTO WEDNESDAY
MORNING.

&&

.PREV DISCUSSION...ISSUED 322 PM EST TUE MAR 4 2014

SHORT TERM...TONIGHT

SOME LINGERING LIGHT SNOW OR SCATTERED SNOW SHOWERS WILL BE IN PLAY
FOR THE TRI CITIES AND NORTHERN THUMB REGIONS LATE THIS AFTERNOON
AND EARLY EVENING IN THE REGION OF BETTER LOW LEVEL MOISTURE.
OTHERWISE...THE VERY DRY AIR CONTINUES TO BE THE DOMINANT FEATURE.

THERE IS STILL A WEAK COLD FRONT ACROSS THE STRAIGHTS AREA INTO
NORTHERN WI THAT WILL DROP THROUGH LOWER MICHIGAN TONIGHT.  AS IT
DOES THERE IS A SMALL JET OVER THE NORTHERN HIGH PLAINS THAT MOVES
ITS EXIT REGION OVER LOWER MICHIGAN LATER TONIGHT AS THE MAIN
ONTARIO UPPER LOWS TROUGH AXIS SWINGS THROUGH THE NORTHERN LAKES.
THERE IS ALSO A BROAD AREA OF WEAK FGEN AND DEFORMATION FROM ABOUT
850 TO 500 MBS. WHILE THE LOW LEVELS...BELOW 6K OR 7K FEET...REMAIN
DRY THIS EVENING THERE IS SOME INDICATION THAT LAYER RH INCREASING
OVERNIGHT. AS THAT DOES THE LAYER FROM 850 TO 700 MB LOSES MOISTURE.
THIS LACK OF MOISTURE STILL APPEARS TO BE THE WINNER TONIGHT DESPITE
SOME DECENT DYNAMICS. THEREFORE...WILL GO WITH NOTHING MORE THAN A
CHANCE OF SNOW SHOWERS. TIMING WILL BE COINCIDENT WITH THE TIMING OF
THE FORCING AND THE FRONTAL BOUNDARY...IN THE FIRST HALF OF THE
NIGHT FOR THE NORTH HALF OF THE FORECAST AREA AND THEN FOR THE
SECOND HALF OF THE NIGHT FOR THE SOUTH HALF OF THE FORECAST AREA.

WILL LEAN TOWARD THE WARMER END OF GUIDANCE WITH EXPECTED CLOUD
COVER TONIGHT AND THE BEST SURGE OF REINFORCING COLD AIR ADVECTION
ON INCREASING NORTHEAST FLOW LATER TONIGHT AND INTO WEDNESDAY.

LONG TERM...

VERY STRONG PV ANOMALY/UPPER LEVEL TROUGH SWINGING THROUGH ONTARIO
TONIGHT...CLIPPING GEORGIAN BAY TOMORROW MORNING. STRONG
SUBSIDENCE BEHIND THIS FEATURE WILL ALLOW 1039-1040 MB SURFACE
HIGH TO BUILD INTO THE EASTERN GREAT LAKES...SETTING US UP FOR
ANOTHER COLD NIGHT WEDNESDAY NIGHT. HOWEVER...BAROCLINIC
ZONE/FGEN...SPECIFICALLY AT THE 700 MB LEVEL COULD PROVE
PROBLEMATIC...AS CLOUDS ARE EXPECTED TO LINGER TOWARD THE OHIO
VALLEY. THERE IS EVEN LOOKS TO BE A LITTLE LIGHT SNOW TOMORROW
TOWARD THE SOUTHERN MICHIGAN BORDER BEFORE THE LAGGING SHORTWAVE
OVER THE UPPER MISSISSIPPI VALLEY/MIDWEST COMPLETELY SHEARS OUT
AND THE DRIER LOW LEVEL AIR TAKES HOLD. SO...WITH SOME CLOUD
CONCERNS WEDNESDAY NIGHT...AND ENOUGH OF AN EASTERLY GRADIENT
SOUTH OF I-69...EXPECTING MINS IN THE SINGLE NUMBERS TO AROUND 10
DEGREES...WITH MINS WELL BELOW ZERO NORTH OF I-69 AS WINDS GO
CALM. THIS IS REFLECTED WELL IN THE NAM SURFACE DEW PT FIELD.

RISING HEIGHTS/UPPER LEVEL RIDGE BUILDING INTO THE GREAT LAKES
REGION THURSDAY-FRIDAY WILL SUPPORT A MODEST WARMUP AHEAD OF AN
APPROACHING COLD FRONT. WITH 925/850 MB TEMPS FORECASTED TO RISE
INTO THE LOW SINGLE NUMBERS ON FRIDAY...THE POTENTIAL FOR MID 40S IS
THERE WITH THE DEVELOPING SOUTH-SOUTHWEST LOW LEVEL FLOW.
HOWEVER...NEED TO FACTOR IN THE SNOW COVER...THE POTENTIAL WE MAY
CLOUD OVER DURING THE AFTERNOON...AND THE COLD START TO THE DAY
(AROUND 10 DEGREES)...AND WILL THUS STAY MORE CONSERVATIVE AND GO
WITH UPPER 30S TO AROUND 40 DEGREES...STILL SLIGHTLY BELOW NORMAL.

THE COLD FRONT LOOKS TO BE COMING THROUGH WITH LITTLE FANFARE
FRIDAY NIGHT...WITH CONTINUED BELOW NORMAL TEMPERATURES FOR THE
WEEKEND.

MARINE...

WEAK SOUTHWEST WINDS THIS AFTERNOON OVER THE MAJORITY OF THE MARINE
WATERS WILL GIVE WAY TO WEAK NORTHEAST WINDS TONIGHT INTO
WEDNESDAY...AS HIGH PRESSURE BUILDS INTO THE CENTRAL/EASTERN GREAT
LAKES WEDNESDAY NIGHT. RETURN FLOW AROUND THIS HIGH WILL SLOWLY KICK
ON THURSDAY OUT OFF THE SOUTHEAST...WITH WINDS THEN VEERING TO
SOUTHERLY DIRECTION ON FRIDAY AHEAD OF A COLD FRONT. EVEN
THEN...WINDS ARE ONLY EXPECTED TO BE IN THE 10 TO 20 KNOT RANGE.

&&

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

&&

$$

AVIATION.....SC
SHORT TERM...RBP
LONG TERM....SF
MARINE.......SF


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