FXUS63 KJKL 301745
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
1245 PM EST MON NOV 30 2009

.SHORT TERM.../THE REST OF TODAY/

FORECAST IS PRETTY MUCH ON TRACK THIS MORNING. COLD FRONT HAS MADE
ITS WAY THROUGH EASTERN KENTUCKY. STILL HAVE A RATHER LARGE AREA OF
POST FRONTAL RAIN SHOWERS TO CONTEND WITH....ALONG WITH SOME PATCHY
DRIZZLE AND ISOLATED SHOWERS FURTHER WEST. BUT PRECIPITATION WILL BE
COMING TO AN END ACROSS THE AREA LATER THIS AFTERNOON. WE SHOULD SEE
SOME PARTIAL CLEARING AS WELL. UPDATE THIS MORNING WAS MAINLY FOR
LATEST TEMPS TRENDS. CLOUDS AND DECENT CAA WILL TEND TO KEEP TEMPS
STEADY THROUGH THE REMAINDER OF THE DAY...DROPPING FROM CURRENT MID
AND UPPER 40S IN OUR SOUTHEASTERN ZONES. ZONES AND ISC GRIDS HAVE
BEEN UPDATED TO ACCOUNT FOR LATEST THOUGHTS AND TRENDS.

THE PREVIOUS SHORT TERM FORECAST DISCUSSION FOLLOWS...

/TODAY THROUGH WEDNESDAY/

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/

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.../18Z TO 18Z/...UPDATED

FORECAST CHALLENGE WILL BE HOW QUICKLY PATCHY DRIZZLE AND LOW CLOUDS
CLEAR OUT THIS AFTERNOON AND EVENING. UPSTREAM OBS SHOW CIGS CLIMBING
FAST. CONSEQUENTLY EXPECT CIGS TO LIFT FROM CURRENT LIFR/MVFR TO VFR
LEVELS DURING THE AFTERNOON. HOWEVER...ALL INDICATIONS ARE THAT VFR
STRATO CU WILL LINGER INTO THIS EVENING. THEREAFTER...SFC HIGH
PRESSURE WILL RAPIDLY TRANSIT THE AREA...CAUSING WINDS VEER OUT OF
THE SOUTH...SOUTHEAST BY TUESDAY. 

&&

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

&&

$$

SHORT TERM...AR/RAY
LONG TERM....SCHOETTMER
AVIATION...RAY