FXUS63 KJKL 020758
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
258 AM EST WED DEC 2 2009

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

WIDESPREAD RAINS ARE ON THE WAY AS INITIAL OVERRUNNING PRECIPITATION
ENCROACHES FROM THE TENNESSEE VALLEY. TEMPERATURES ARE HOVERING IN
THE MIDDLE 30S IN THE COOLER VALLEYS ALONG AND SOUTH OF THE HAL
ROGERS PARKWAY AND HIGHWAY 80...WITH SHELTERED VALLEYS HOLDING IN THE
LOWER 30S TO THE NORTH. DO NOT EXPECT THERE TO BE ANY FREEZING RAIN
OUT OF THIS AT THE ONSET IN THE NORTH WITH GROUND TEMPERATURES WELL
ABOVE FREEZING AS WELL AS A SIGNIFICANT WARM NOSE IN PLACE AT 850 MB.

ALL MODELS ARE CLUSTERED WELL WITH TRACKING DEEPENING LOW PRESSURE
ACROSS THE TENNESSEE VALLEY AND THROUGH CENTRAL KENTUCKY BY THIS
EVENING. A STRONG LOW LEVEL JET WILL PROVIDE A THREAT FOR GUSTY WINDS
IN THE SOUTHEASTERN TERRAIN...SO WILL LET THE ADVISORY RIDE. 

ST READY RAINFALL WILL TAPER OFF EARLY THIS EVENING...WITH THE THREAT
OF VERY LIGHT RAIN OR DRIZZLE LINGERING THROUGH THURSDAY EVENING...AS
COLDER AIR MOVES IN FROM BEHIND THE DEPARTING SYSTEM. ICE CRYSTALS
LOOK EVEN TOUGHER TO COME BY COMPARED TO LAST NIGHT...SO ONLY
MENTIONED DRIZZLE. EXPECT MOISTURE TO BE SHALLOW ENOUGH BY THE TIME
THE HIGHEST SOUTHEAST TERRAIN GOES SUB-FREEZING TO AVOID ANY
GLAZING.

DRY BUT COLD CONDITIONS WILL REIGN ON FRIDAY AS A SURFACE HIGH
PRESSURE RIDGE BUILDS IN. POPS WILL RAMP BACK UP LATE FRIDAY NIGHT AS
FULL LATITUDE TROUGH AXIS MOVES IN FROM THE WEST. MAINTAINED THE 20
TO 30 POPS FOR NOW WITH THIS SYSTEM AT ONSET. ANYTHING THAT FALLS
WILL BE SNOW...HOWEVER LIGHT QPF WILL LIMIT ACCUMULATIONS TO MAINLY
THE HIGHER TERRAIN.

FOR TEMPERATURES...STUCK CLOSE TO PERSISTENCE...WHICH JIVES WELL WITH
THE CURRENT GUIDANCE FOR THE FIRST 24 HOURS...THEN UNDERCUTS GUIDANCE
SIGNIFICANTLY ON THE HIGHS FOR THURSDAY AND FRIDAY...GIVEN THE CLOUDS
AND COLD AIR MASS IN PLACE. 

.LONG TERM.../SATURDAY THROUGH TUESDAY/

BETTER THAN USUAL AGREEMENT IN EXTENDED MODEL SOLUTIONS...THROUGH 
MONDAY AND THEN THE ECMWF HAS A ZONAL PATTERN...WHEREAS THE GFS 
DEVELOPS A TROUGH ACROSS THE WESTERN US. SO CONFIDENCE IS MUCH 
BETTER THAN NORMAL THROUGH MONDAY AND THEN SHARPLY DECLINES. 

ON SATURDAY...A SHORT WAVE WILL QUICKLY MOVE ACROSS THE AREA. AS IT 
DOES...THE MODELS ARE DEVELOPING PRECIPITATION ACROSS THE AREA EVEN 
THOUGH THE AREA IS BEING DOMINATED BY HIGH PRESSURE AND THE LOW 
LEVEL FLOW IS FROM THE NORTHWEST. THIS SYSTEM WILL BE CLIPPER LIKE 
AND THE BEST CHANCE TO GET ANY SNOWFALL TO DEVELOP ARE IN THOSE 
AREAS THAT GET HELP FROM UPSLOPE. I AM NOT TOTALLY CONVINCED THE 
MOST OF THE AREA WILL GET MEASURABLE PRECIPITATION...BUT IT MIGHT BE 
MORE LIKE DRIZZLE AND FLURRIES...DEPENDING ON THE TEMPERATURES. 
THINGS THEN REMAIN DRY UNTIL THE NEXT SYSTEM MOVE INTO THE AREA ON 
TUESDAY AFTERNOON. THE TIMING OF THIS SYSTEM IS STILL VERY MUCH IN 
DOUBT. FOR TEMPERATURES...JUST NUDGED THEM TOWARD CURRENT MODEL 
TRENDS AS THE PREVIOUS SHIFT HAD AN EXCELLENT TEMPERATURE FORECAST.

&&

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

VFR CONDITIONS WILL PREVAIL UNTIL 9Z TO 14Z...WHEN CLOUDS AND
PRECIPITATION IN ADVANCE OF AN AREA OF LOW PRESSURE REACH THE AREA.
INITIALLY THESE WILL BE MID OR HIGH CLOUDS...BUT THEY WILL THICKEN
AND LOWER OVERNIGHT AS THE RAIN BEGINS TO FALL AND LOWER THE CEILING.
THE CEILING SHOULD BE STEADILY LOWERING FROM 9Z TO 15Z AND SHOULD
BECOME IFR BY 15Z AND STAY IN THE CATEGORY THROUGH 00Z. CIG HEIGHTS
AND VSBY MAY FLUCTUATE BETWEEN IFR AND MVFR FROM 18Z AS HEAVIER
SHOWERS MOVE OVERHEAD. AFTER 01Z...THE FORCING BECOMES MUCH WEAKER
AND THE SHOWERS SHOULD TAPER OFF AND THE CIGS WILL IMPROVE. THE
WINDS SHOULD PICK UP AS THE FRONT MOVES THROUGH THE AREA.

&&

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

&&

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