FXUS63 KJKL 112013
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
313 PM EST FRI DEC 11 2009

.SHORT TERM.../TONIGHT THROUGH SUNDAY NIGHT/...UPDATED

AN AREA OF HIGH PRESSURE CURRENTLY CENTERED ACROSS THE TENNESSEE
VALLEY WILL GRADUALLY SLIDE EAST TONIGHT. HIGH CLOUDS STREAMING ALOFT
ON A FAST MOVING JET WILL SUBSIDE TONIGHT...LEAVING SKIES MAINLY
CLEAR...AND ALLOWING TEMPERATURES TO BOTTOM OUT SIMILAR TO LAST NIGHT
WITH DEWPOINTS IN THE SINGLE DIGITS. HIGH CLOUDS WILL RETURN TOWARDS
DAWN HOWEVER...AS ANOTHER WEAKER JET STREAK TRANSPORTS MOISTURE.

THE NEXT SYSTEM WILL APPROACH ON SATURDAY AS A LOW LEVEL JET ALONG
WITH AN ACCOMPANYING SHORT WAVE TROUGH TAKE AIM AT THE AREA. THERE IS
STILL SOME QUESTION AS TO WHETHER OR NOT LOCATIONS NORTH OF THE
MOUNTAIN PARKWAY WILL START WITH A BRIEF ONSET OF FROZEN
PRECIPITATION. BASED ON THE LATEST FORECAST SOUNDINGS AND TIME HEIGHTS...
THINK THERE IS A SLIGHT CHANCE OF SLEET AT ONSET...HOWEVER THIS WILL
BE MAINLY A PLAIN RAIN EVENT AND DO NOT FORESEE ANY SIGNIFICANT
IMPACTS.

LIGHT RAIN WILL LINGER INTO SUNDAY...BEFORE TAPERING OFF BY LATE IN
THE DAY AS THE DEEPER MOISTURE EXITS.

FOR TEMPERATURES...STAYING ON THE COOL SIDE FOR THE LOWS AND HIGHS
HAS WORKED WELL AND CONTINUING WITH THIS TREND...ESPECIALLY ON LOWS
TONIGHT AND HIGHS TOMORROW WITH A QUICK INCREASE IN CLOUDS. READINGS
WILL ACTUALLY RISE THROUGH TOMORROW NIGHT AND INTO SUNDAY...WITH NOT
MUCH OF A DROP SUNDAY NIGHT. STUCK CLOSER TO GUIDANCE HERE...ALTHOUGH
DID SHRINK THE DIURNAL RANGE A BIT WITH LINGERING LOW LEVEL CLOUD
COVER. 

.LONG TERM.../MONDAY THROUGH FRIDAY/...UPDATED

COLD FRONT TO ARRIVE EARLY TUE. GFS/ECMWF/CANADIAN SHOW FAIR 
AGREEMENT ON TIMING AND EACH WITH LESS THAN 0.10 INCH QPF. GFS
HAS MOISTURE NO DEEPER THAN 800 MB BUT UPWARD MOTION IS A LITTLE 
BETTER THAN PREVIOUS RUNS AND BETTER COINCIDENT WITH THE MOISTURE 
AVAILABLE. SO VERY LIGHT RAIN WITH THIS EVENT LOOKS GOOD BUT KEPT 
PROBABILITY AT CHANCE AND MUCH TOO WARM FOR ANY PHASE OTHER THAN 
LIQUID PRECIPITATION.  

THEREAFTER THE LONGWAVE PATTERN AMPLIFIES FROM THIS FAST ZONAL FLOW 
TO TROUGH OVER EAST COAST. GFS ENSEMBLE SHOWS A FAIRLY WIDE SOLUTION 
AT THE END OF THE WEEK OVER SNOW POSSIBILITIES AND SOME INDICATE A 
LAKE EFFECT SNOW CONNECTION TO LAKE MI. THAT SCENARIO IS A MAJOR 
CHANGE FROM 00Z AND 06Z RUNS AND DIFFERENT STILL FROM ECMWF. BUT 
SOMETHING TO WATCH.

STUCK CLOSE TO MEX TEMPERATURES THOUGH ENSEMBLE 850 MB STANDARD 
DEVIATION BECOMES QUITE LARGE TOWARD THE LATTER HALF OF WEEK...WHICH 
JUST HIGHLIGHTS THAT A PATTERN CHANGE IS COMING.  

&&

.AVIATION.../18Z TO 18Z/

HIGH PRESSURE WILL CONTINUE TO PROVIDE VFR CONDITIONS AND LIGHT WINDS
THROUGH THE PERIOD. SOME HIGH CLOUDS WILL BE SEEN THROUGH EARLY THIS
EVENING AND THEN AGAIN BY 18Z TOMORROW OUT AHEAD OF THE NEXT
APPROACHING SYSTEM.

&&

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

&&

$$
SHORT TERM...GEOGERIAN
LONG TERM...GV
AVIATION...GEOGERIAN