FXUS63 KJKL 030803
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
303 AM EST THU DEC 3 2009

.SHORT TERM.../TODAY THROUGH SATURDAY NIGHT/...UPDATED

DEEP LOW PRESSURE AND THE UPPER LEVEL LOW ARE PULLING AWAY QUICKLY.
MEASURABLE PRECIPITATION WILL BE GONE BEFORE 12Z...SO WILL ONLY
MENTION SOME DRIZZLE INTO TONIGHT...WITH ONGOING COLD AIR ADVECTION.
HIGHS WILL LIKELY BY AROUND 12Z...WITH STEADY OR SLOWLY FALLING
TEMPERATURES FOR THE REST OF THE DAY. HIGH PRESSURE WILL BUILD IN FOR
FRIDAY...HOWEVER PLENTY OF CLOUDS WILL LINGER ACROSS THE AREA WITH
WNW LOW LEVEL FLOW. 

THE NEXT SYSTEM OF INTEREST WILL APPROACH EARLY SATURDAY MORNING AS
A TROUGH AXIS SHIFTS EAST ACROSS THE AREA. THE MODELS HAVE ALL BEEN
CONSISTENTLY SHOWING LIGHT QPF FOR THE MAJORITY OF THE AREA DURING
THE DAY ON SATURDAY. COLD TEMPERATURES ALOFT WILL ALLOW THIS TO BE
ALL SNOW.

THE TIME HEIGHTS REVEAL A TIGHT GRADIENT FROM NORTHWEST TO SOUTHEAST
ON HOW QUICKLY THE COLUMN CAN SATURATE WHILE FORCING IS AVAILABLE.
HAVE BUMPED POPS UP TO GOOD CHANCE FOR THE SOUTHEASTERN TWO THIRDS OF
THE AREA. DESPITE THIS FALLING ALL AS SNOW...THE WINDOW OF SNOW LOOKS
TO BE FROM THE LATE MORNING HOURS THROUGH THE EARLY AFTERNOON...SO DO
NOT EXPECT MUCH ACCUMULATION ON THE ROADS. IN THE SOUTHEASTERN
TERRAIN...ESPECIALLY ABOVE 2500 FEET...THE IMPACT WILL BE GREATER
WITH TEMPERATURES LIKELY REMAINING BELOW FREEZING ALL DAY. COULD SEE
LOCATIONS PICKING UP AN INCH OR SO FOR THESE LOCATIONS. WILL
HIGHLIGHT THIS IN THE HWO. 

FORCING WILL END BY 00Z SUNDAY...WITH DECREASING CLOUDS AND A COLD
NIGHT DOWN INTO THE LOWER 20S EXPECTED.

FOR TEMPERATURES...GENERALLY STAYING COLDER THAN GUIDANCE ON
ON THE HIGHS...AND CLOSER ON THE LOWS...AS A DIURNALLY LIMITED RANGE
WORKS WELL IN COLD AIR ADVECTION.

.LONG TERM.../SUNDAY THROUGH WEDNESDAY/

IN GENERAL...THE MODELS ARE IN BETTER THAN AVERAGE AGREEMENT...WITH 
SLIGHT UPPER RIDGING AND SURFACE HIGH OVER THE OHIO VALLEY. BY 
MONDAY MORNING..THE SURFACE RIDGE BEGINS TO BE PUSHED TO THE EAST 
AND SOME RETURN FLOW AT THE SURFACE WILL BRING SOME WARMER AND 
MOISTER AIR INTO THE AREA AHEAD OF THE APPROACHING FRONT. A WEAK 
WARM FRONT WILL MOVE ACROSS THE AREA BY MONDAY AFTERNOON AND THEN A 
WEAK COLD FRONT WILL MOVE ACROSS THE AREA ON MONDAY NIGHT. THE ECMWF 
IS NOW SHOWING A FAIRLY POTENT SYSTEM WITH A STRONG UPPER LOW WILL 
MOVE ACROSS THE AREA ON TUESDAY NIGHT AND WEDNESDAY. IN 
GENERAL...TRENDED TOWARD THE ECMWF AND USED SOME RAW MODEL DATA TO 
BLEND WITH THE GFS MOS. THE BIGGEST QUESTIONS WILL BE TEMPERATURES 
AS THE SYSTEMS MOVE ACROSS THE AREA. AT THIS TIME...DO NOT SEE AND 
LARGE SNOW PRODUCERS. THE BEST CHANCE FOR MEASURABLE SNOW WILL BE 
WITH THE POST FRONTAL PRECIPITATION ON THURSDAY.   

&&

.AVIATION.../06Z TO 06Z/

A COLD FRONT WILL PASS THROUGH THE REGION FROM WEST TO EAST BETWEEN
07Z AND 09Z...LIKELY BRINGING SHOWERS AND GUSTY WINDS. WEST SOUTHWEST
WINDS WILL INCREASE BEHIND THE FRONT...WITH GUSTS OF 20-25 KNOTS. THE
WIND WILL GRADUALLY DIMINISH OVERNIGHT AND THURSDAY MORNING.
GENERALLY MVFR CONDITIONS AHEAD OF THE FRONT WILL DETERIORATE AFTER
THE FRONT PASSES...FALLING TO MAINLY IFR CEILINGS. BEHIND THE FRONT
THERE SHOULD BE A DRY PERIOD UNTIL MID MORNING. THE WRAP AROUND FROM
THIS SYSTEM WITH A POST FRONTAL TROUGH SHOULD MOVE THROUGH THE AREA
AROUND 14-16Z. WITH THIS TROUGH...EXPECT DRIZZLE AND IFR CONDITION TO
HANG IN THERE THROUGH THE END OF THE PERIOD. SOME OF THE MOS GUIDANCE
EVEN FORECAST 800 FT CIGS. DECIDED TO JUST KEEP A SCT DECK BELOW 1000
FT AND KEEP THE CIGS AROUND 1200. MTN TOP TO ALONG THE VA BORDER WILL
LIKELY BE OBS CURRED. WOULD NOT BE SURPRISED TO SEE SOME TEMPO BELOW
1000 FT DURING THE AFTERNOON AND EARLY EVENING.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$
SHORT TERM...GEOGERIAN
LONG TERM...JJ
AVIATION...JJ