FXUS63 KJKL 151135
AFDJKL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
635 AM EST TUE DEC 15 2009

.SHORT TERM.../TODAY THROUGH THURSDAY/

07Z SFC ANALYSIS SHOWS LOW PRESSURE ENTERING NORTHERN NEW ENGLAND
WITH A DIFFUSE COLD FRONT STRETCHED SOUTHWEST THROUGH THE SOUTHERN
APPALACHIANS AND INTO THE DEEP SOUTH. MEANWHILE...TO THE WEST OF THE
FRONT...A STRONG AND LARGE ARCTIC HIGH LIES OVER THE HIGH PLAINS AND
IS PUSHING INTO THE OHIO VALLEY. LOCALLY...THIS FRONT HAS MOVED EAST
OF JKL AND IS KICKING OFF A BAND OF LIGHT RAIN AND DRIZZLE OVER FAR
EASTERN PORTIONS OF THE CWA. THROUGHOUT EAST KENTUCKY...LOW CLOUDS
ASSOCIATED WITH THE FRONT BLANKET THE AREA. IN CONJUNCTION WITH THE
PASSAGE OF THE FRONT...COLDER AIR WILL ARRIVE ON NORTHWEST WINDS.
TEMPERATURE READINGS THROUGH THE AREA RANGE FROM NEAR 60 DEGREES
AHEAD OF THE FRONT IN THE FAR EAST WHILE UPPER 40S ARE POISED TO
ENTER NORTHWESTERN PORTIONS OF THE CWA. DEWPOINTS ARE LIKEWISE
STRIATED FROM LOWER 50S IN THE EAST TO THE LOWER 40S IN THE FAR
NORTHWEST.

THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM PORTION OF
THE FORECAST. THEY AGREE THAT A SHALLOW TROUGH WILL SWING THROUGH THE
GREAT LAKES AND OHIO VALLEY TODAY WITH PLENTY OF SHORTWAVE ENERGY
ACCOMPANYING THIS TRANSITION. IN THE WAKE OF THIS TROUGH...HEIGHTS
WILL RISE OVER THE OHIO VALLEY INTO THURSDAY. FOLLOWING THIS...THE
MAIN TROUGH DEEPENS OVER NOVA SCOTIA AND STARTS TO PIVOT NORTHWEST
BACK INTO CANADA. MEANWHILE...PACIFIC ENERGY WILL DROP SOUTHWEST
THROUGH THE ROCKIES HELPING TO INITIATE A SIGNIFICANT AMPLIFICATION
OF THE PATTERN THROUGH THE MIDWEST THAT APPEARS POISED TO BRING ABOUT
A CHILLY WEEKEND FOR KENTUCKY. HOWEVER...THROUGH THURSDAY...MINOR
RIDGING AHEAD OF THIS WESTERN ENERGY WILL BRING A BRIEF PERIOD OF
BENIGN AND MILDER WEATHER TO THE OHIO VALLEY.

SENSIBLE WEATHER WILL FEATURE FALLING TEMPERATURES FOR THE REMAINDER
OF THE NIGHT AND THE POCKETS OF LIGHT RAIN AND DRIZZLE MOVING EAST...
TRAILING THE FRONT. TEMPERATURES WILL CONTINUE TO SLOWLY FALL
THROUGH THE DAYLIGHT HOURS TODAY WITH A QUICKER DROP EXPECTED THIS
EVENING AS THE ARCTIC HIGH MOVES BODILY INTO THE REGION. ANY
LINGERING DRIZZLE AND LIGHT RAIN IN THE EAST WILL CLEAR OUT BY
AFTERNOON...WELL BEFORE TEMPERATURES FALL BELOW FREEZING LATER THIS
EVENING. SKIES WILL CLEAR FROM WEST TO EAST LATE TODAY ASSOCIATED
WITH THE DRIER AIR AND THE STRONG HIGH MOVING INTO THE AREA. EXPECT
TEMPERATURES TO FALL INTO THE LOWER 20S IN MOST AREAS TONIGHT THANKS
TO MOSTLY CLEAR SKIES AND NEAR CALM WINDS. THE HEART OF THE
MODERATING ARCTIC HIGH WILL BE OVERHEAD ON WEDNESDAY KEEPING
TEMPERATURES BELOW NORMAL DESPITE PLENTY OF SUNSHINE. AS THE HIGH
STARTS TO SHIFTS OFF TO THE EAST WEDNESDAY NIGHT...EXPECT FAVORABLE
CONDITIONS TO DEVELOP FOR A RIDGE TO VALLEY TEMPERATURE SPLIT. THE
HIGH/S INFLUENCE WANES ON THURSDAY WITH CLOUDS INCREASING ACROSS THE
NORTH EVEN AS TEMPERATURES END UP CLOSE TO NORMAL.

FOR THE NEXT 24 HOURS...FOLLOWED THE RAW NAM12 TEMPS MOST CLOSELY TO
BETTER CAPTURE THE ANTICIPATED NON-DIURNAL CURVE INTO WEDNESDAY
MORNING. AFTER THAT...A BLEND OF THE MET AND MAV WERE FOLLOWED FOR
HIGHS WHILE THE LOWS ON WEDNESDAY NIGHT WERE FURTHER ADJUSTED FOR
RELATIVE TOPOGRAPHY. AS FOR POPS...LINGERED NEAR 20 PERCENT IN THE
EAST THROUGH THE MORNING TODAY AND THEN FOLLOWED COURSE WITH SINGLE
DIGIT NUMBERS THROUGH THE REMAINDER OF THE SHORT TERM PORTION OF THE
FORECAST. 

.LONG TERM.../THURSDAY NIGHT THROUGH MONDAY/

GFS/ECWMF/CANADIAN MODELS AGREE THAT A STRONG 5H LOW/TROUGH WILL 
SWING WESTWARD THEN SOUTH THIS WEEKEND. THEY DIFFER GREATLY ON 
TIMING WITH ECMWF BEING FASTEST WHILE CANADIAN HANGS IT UP IN 
WESTERN ONTARIO BY SUNDAY MORNING. GFS TAKES THE PRIMARY LOW 
WESTWARD TO THE GREAT LAKES...WHICH IS THE MIDDLE GROUND BETWEEN
THE OTHER TWO BUT MAYBE HARDER TO ACCEPT GIVEN ITS WESTERN CONUS 
RIDGE ALMOST COMPLETELY EVAPORATES. ALL OF THESE SCENARIOS TURN
EAST KY COLDER WITH A CHANCE OF SNOW THROUGH THE WEEKEND AND INTO 
MONDAY. WILL KEEP THE PROBABILITIES OF SNOW THIS PERIOD THE SAME 
GIVEN THEY ARE HIGHER THAN NEIGHBORING AREAS. VERY LITTLE ADJUSTMENT 
MADE TO TEMPERATURES AND DO NOT AGREE WITH THE WARMER 12Z MEX DATA.

&&

.AVIATION.../12Z TO 12Z/...UPDATED

PATCHY SPRINKLES WILL BE POSSIBLE AT THE TAF SITES THROUGH EARLY THIS
AFTERNOON...AS MOIST NORTHWEST FLOW RIDES UP THE HILLS AND MOUNTAINS
OF EASTERN KENTUCKY TODAY. A DECK OF CLOUDS WITH BASED BETWEEN 2 AND
4K WILL BLANKET THE SKY THROUGH 0 OR 1Z TONIGHT BEFORE FINALLY
CLEARING OFF BETWEEN 2 AND 3Z. THERE SHOULD BE JUST ENOUGH WIND
OVERNIGHT TO KEEP FOG FORMATION TO A MINIMUM. THE TAF SITES WILL SEE
CONDITIONS FLUCTUATING BACK AND FORTH BETWEEN MVFR AND VFR WITH
REGARDS TO CIGS THROUGH OUT THE DAY...WITH JKL SEEING THE LONGEST
PERIOD OF MVFR CIGS AROUND 2K. LOZ AND SME SHOULD SEE CIGS MOSTLY
AROUND 3.5-4K...BUT COULD SEE THE OCCASIONAL SHORT PERIOD OF MVFR
CIGS AROUND 2.5K.

&&

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

&&

$$

SHORT TERM...GREIF
LONG TERM....GV
AVIATION...AR