222 
FXUS63 KJKL 230755
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
255 AM EST SUN NOV 23 2008

.SHORT TERM.../TODAY THROUGH MONDAY/...UPDATED

SURFACE HIGH PRESSURE WILL SLIDE ACROSS THE CAROLINAS INTO THE
WESTERN ATLANTIC TODAY AND TONIGHT. ALOFT... A SHORTWAVE RIDGE WILL
MOVE ACROSS THE BLUEGRASS STATE TODAY WHILE HEIGHTS FALL OVER THE
UPPER MIDWEST AS A POTENT SHORTWAVE DIGS SOUTHEAST OUT OF CENTRAL
CANADA. SURFACE LOW OVER THE PLAINS WILL SHIFT EAST TONIGHT... THEN
DEEPEN AS IT MOVES INTO THE GREAT LAKES REGION ON MONDAY. ATTENDANT
COLD FRONT WILL QUICKLY MOVE ACROSS THE OHIO AND TENNESSEE VALLEYS
ON MONDAY BRINGING ANOTHER SHOT OF PRECIPITATION... SOME POSSIBLY OF
THE WINTRY VARIETY... TO EASTERN KENTUCKY.

PLENTY OF SUNSHINE EXPECTED TODAY WITH THE HIGH PRESSURE TO OUR
EAST. SOUTHERLY WINDS WILL INCREASE SOME AND TEMPS SHOULD RESPOND TO
THE WARM ADVECTION REACHING HIGHS AROUND 50.

THE FOCUS THEN SHIFTS TO THE APPROACHING STORM SYSTEM TO OUR WEST.
INITIAL AIRMASS DURING THE EVENING IS VERY DRY BUT ISENTROPIC LIFT
AHEAD OF THE COLD FRONT SHOULD RESULT IN A QUICK INCREASE IN CLOUD
COVER DURING THE LATE EVENING HOURS... FOLLOWED CLOSELY BY THE
DEVELOPMENT OF PRECIPITATION TO OUR SOUTH AND WEST. DESPITE THE
INITIALLY DRY CONDITIONS... MODELS (GFS/NAM/SREF) ALL POINT TO
PRECIP QUICKLY DEVELOPING FROM SOUTHWEST TO NORTHEAST DURING THE
PRE-DAWN HOURS. THERMAL PROFILES ARE WARM ENOUGH IN THE LOW LEVELS
THAT THE MAJORITY OF THE PRECIP SHOULD BE LIQUID... ALTHOUGH A
LITTLE SLEET AND MAYBE SOME SNOW ARE POSSIBLE INITIALLY DUE TO WET
BULBING. SURFACE TEMPS ARE PROBLEMATIC THOUGH AS VERY GOOD
RADIATIONAL COOLING CONDITIONS WILL BE IN PLACE EARLY IN THE EVENING
AND TEMPS IN OUR EASTERN VALLEYS WILL LIKELY FALL QUICKLY TO
FREEZING OR BELOW. IF RAIN DEVELOPS ACROSS OUR AREA LATE TONIGHT...
AND IT LOOKS LIKE IT WILL... AREAS OF FREEZING RAIN ARE THEREFORE
POSSIBLE. STILL TOO MUCH UNCERTAINTY FOR ANY KIND OF HEADLINES BUT
SOME LIGHT ICE ACCUMULATIONS ARE POSSIBLE... ESPECIALLY FOR VALLEY
LOCATIONS EAST OF A LINE EXTENDING FROM MOREHEAD TO BEATTYVILLE TO
MIDDLESBORO.

WARM ADVECTION SHOULD THEN TURN ALL PRECIP OVER TO RAIN QUICKLY
MONDAY MORNING WITH CATEGORICAL POPS NEEDED DURING THE DAY AS THE
FRONT WORKS ACROSS THE AREA. GENERALLY ONE-HALF TO THREE-QUARTERS OF
AN INCH OF RAINFALL IS ANTICIPATED WITH THE SYSTEM.

.LONG TERM.../MONDAY NIGHT THROUGH SATURDAY/...UPDATED

THE MODELS WERE IN VERY GOOD AGREEMENT THROUGH THURSDAY AND THEN
STARTED TO DIVERGE. THE BIGGEST AREA OF DISAGREEMENT IS THE HANDLING
OF THE UPPER TROUGH OVER THE WESTERN US AND HOW IT WILL PROGRESS
INTO THE AREA IN THE LATER PART OF THE WEEK. AS SUCH...THE
CONFIDENCE AFTER THURSDAY DECREASES SIGNIFICANTLY. HOPEFULLY...THE
MODELS WILL SYNC UP BETTER OVER THE NEXT COUPLE OF DAYS.

MADE VERY FEW CHANGES TO THE PREVIOUS FORECAST. KEPT THE TIMING THE
SAME AND ONLY MADE MINOR TWEAKS TO THE TEMPERATURES. I WOULD
DEFINITELY LEAN TOWARD THE ECMWF SOLUTION FOR LATER IN THE
WEEK...HOWEVER...CONFIDENCE IS STILL LOW. THE WAY THE PATTERN IS
SETTING UP...IT IS CONCEIVABLE THAT THERE COULD BE SOME FREEZING
PRECIPITATION DEVELOP LATE FRIDAY NIGHT INTO EARLY SATURDAY MORNING.
IT IS FAR TOO EARLY TO REALLY NAIL DOWN A FORECAST LIKE THIS BECAUSE
OF THE TIMING REQUIRED FOR ALL THE PIECES TO COME TOGETHER TO MAKE
THIS HAPPEN.

&&

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

VFR CONDITIONS WILL DOMINATE WITH LIGHT WINDS THROUGH THE BULK OF
THE FORECAST PERIOD. MID LEVEL CEILINGS WILL SCATTER OUT OVER THE
NEXT FEW HOURS AS RESPONSIBLE MID LEVEL DISTURBANCE PASSES ACROSS
THE AREA. THEREAFTER...LOOK FOR CLEARING AND A LIGHT SOUTHERLY
GRADIENT WIND TO DEVELOP DURING THE DAY ON SUNDAY. NEXT STORM SYSTEM
ORGANIZING TO OUR WEST WILL JUST BEGIN TO SPREAD CLOUD COVER TOWARD
THE TAF SITES BY THE END OF THE PERIOD. SOUTHWESTERLY WINDS JUST
ABOVE THE SURFACE WILL ALSO STRENGTHEN TOWARD THE END OF THE PERIOD
BUT LLWS CRITERIA WILL LIKELY NOT BE MET UNTIL AFTER 06Z.

&&

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

&&

$$

SHORT TERM...ABE
LONG TERM...JJ
AVIATION...ABE