FXUS63 KJKL 300749
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
249 AM EST MON NOV 30 2009

.SHORT TERM.../TODAY THROUGH WEDNESDAY/...UPDATED

THE PRIMARY FORECAST PROBLEM FOR DAYS 1-3 WAS THE TIMING OF AN
APPROACHING COLD FRONT AND THE PRECIPITATION ASSOCIATED WITH IT.
BASED ON THE LATEST RADAR IMAGERY...AND THE LATEST SREF AND NAM12
MODEL RUNS...IT APPEARS THAT THE RAIN WILL BE SLOWER TO EXIT THE AREA
THAN THE PREVIOUS FORECAST WAS DEPICTING. AS A RESULT...MODIFICATIONS
WERE MADE TO THE POP...QPF...WEATHER...AND SKY GRIDS BASED ON THE
ABOVE OBSERVATIONS. ALSO INCREASED POPS FOR THE 0-6Z PERIOD ON
WEDNESDAY NIGHT...AS THE GFS...CANADIAN...AND SREF MODELS ALL HAVE
THE PRECIPITATION MOVING INTO THE AREA SLIGHTLY FASTER THAN WHAT THE
PREVIOUS GRID WERE REFLECTING. A FEW MINOR TWEAKS WERE ALSO MADE TO
THE HOURLY AND MAX TEMPERATURE FORECAST FOR TODAY...BUT NOTHING THAT
WILL CHANGE THE OVERALL FORECAST. THE REST OF THE FORECAST WAS IN
GOOD SHAPE.

.LONG TERM.../WEDNESDAY NIGHT THROUGH SUNDAY/...UPDATED

HAVE INCLUDED A PERIOD OF LIKELY POPS LATE WEDNESDAY INTO WEDNESDAY
EVENING AS SURFACE LOW TRAVERSES THE REGION. THERE IS...AND WILL BE
...CONTINUED MODEL DISAGREEMENT ON WHERE THE SURFACE LOW ACTUALLY
TRACKS. THIS FINAL TRACK OF THE LOW WILL BE KEY TO EXACTLY WHERE AND
WHEN A CHANGE OVER TO RAIN AND SNOW SHOWERS BEGINS. AT THIS POINT IT
LOOKS AS THOUGH WEDNESDAY NIGHT WILL SEE THE BEST CHANCE FOR SOME
SNOW SHOWERS WITH SOME LINGERING CHANCES INTO THURSDAY AFTERNOON. DO
NOT EXPECT ANY ACCUMULATION AT THIS POINT. OVERALL...MODELS HAVE COME
INTO BETTER AGREEMENT ON THE EVOLUTION OF THIS SYSTEM WITH GENERAL
AGREEMENT FROM ECMWF/GFS/CMC. HOWEVER INDIVIDUAL DETAILS DO EXIST AND
THE COLDEST GFS SOLUTION WOULD SUGGEST A LONGER PERIOD OF SNOW WITH
SOME POSSIBLE ACCUMULATION. THE WARMER ECMWF SOLUTION SUGGESTS ONLY A
BRIEF CHANGEOVER TO SNOW WITH MOSTLY FLURRIES AT THE END. HAVE
CONTINUED TO GO MIDDLE OF THE ROAD UNTIL EVENT NEARS. ONE OTHER ITEM
OF NOTE IS THAT A PERIOD OF FAIRLY STRONG DOWNSLOPE FLOW OVER THE
SOUTHEAST TERRAIN SHOULD LIMIT PRECIP HITTING THE GROUND ON WEDNESDAY
AND WEDNESDAY EVENING IN THE SOUTHEAST TERRAIN. HAVE CONTINUED TO
DEPICT THIS IN THE GRIDS.

AS FAR AS TEMPERATURES ARE CONCERNED...TUESDAY SHOULD BE A PLEASANT 
DAY UNDER PARTLY CLOUDY TO MOSTLY SUNNY SKIES AND HIGHS RIGHT AROUND 
50 DEGREES. TUESDAY NIGHT SHOULD GENERALLY BE IN THE MID 30S FOR 
LOWS WITH A SUBTLE SPLIT BETWEEN RIDGES AND VALLEYS. WITH THE 
APPROACH OF THE SYSTEM ON WEDNESDAY...TEMPERATURES SHOULD STRUGGLE A 
BIT UNDER AMPLE CLOUD COVER AND INCREASING RAIN COVERAGE. AT THIS 
POINT HIGHS IN THE UPPER 40S SEEM REASONABLE. THE SYSTEM DRAGS THE 
POWERFUL COLD FRONT THROUGH ON WEDNESDAY NIGHT WITH GRADUALLY 
FALLING TEMPERATURES IN THE LOW TO MID 30S. WILL SEE LITTLE IN THE 
WAY OF RECOVERY ON THURSDAY AS STRONG COLD AIR ADVECTION COMBINES 
WITH CONTINUED HEAVY SKY COVER. SURFACE HIGH PRESSURE BUILDS INTO 
THE AREA OVER THE WEEKEND HIGHS IN THE LOWER 40S AND LOWS IN THE IN 
THE UPPER 20S TO AROUND 30 DEGREES. ONCE AGAIN...IT IS IMPORTANT TO 
UNDERSTAND THAT THESE TEMPERATURES ARE BASED ON A COMPROMISE BETWEEN 
MODEL SURFACE LOW TRACKS. CHANGES IN THIS TRACK WILL HAVE A 
SIGNIFICANT IMPACT ON TEMPERATURES AND COULD RESULT IN MORE OR LESS 
SNOWFALL. 

&&

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

MID AND LOW CLOUDS HAVE MOVED INTO THE AREA IN ADVANCE OF A COLD
FRONT. SHOWERS HAVE BEEN OBSERVED ON RADAR FROM AROUND BIG SANDY TO
SOMERSET. CIGS HAVE LOWERED TO MVFR CIGS AT ALL TAF SITES AND WILL
CONTINUE TO LOWER WITH TIME...ESPECIALLY ONCE THE FRONT GETS CLOSER.
COLD FRONT CURRENTLY ANALYZED FROM JUST WEST OF CMH/SDF/BWG. THE COLD
FRONT WILL MOVE THROUGH EASTERN KENTUCKY BETWEEN ABOUT 8Z AND
13Z...WITH GUSTY WINDS GRADUALLY SHIFTING TO THE WEST AND NW BEHIND
IT. CIGS WILL FALL INTO THE IFR RANGE ALONG AND BEHIND THE
FRONT...WITH LIFR OR POSSIBLY BRIEF VLIFR ON RIDGETOP LOCATIONS. AN
END TO THE SHOWERS AND SCATTERING OUT OF THE LOW CLOUDS SHOULD BEGIN
ABOUT 16Z...WITH CIGS IMPROVING TO VFR WEST AND MVFR EAST BY THE END
OF THE PERIOD.

&&

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

&&

$$
SHORT TERM...AR
LONG TERM...SCHOETTMER
AVIATION...DUSTY