FXUS63 KLMK 010442
AFDLMK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
1142 PM EST MON NOV 30 2009

...UPDATED AVIATION DISCUSSION...

...FORECAST UPDATE...

UPDATING THE GRIDS TO REMOVE ALL CLOUDS THROUGH THE OVERNIGHT HOURS. 
ALSO DROPPED LOWS A FEW DEGREES GIVEN THE CURRENT HOURLY TEMPS 
AROUND FREEZING ALREADY. DID NOT GO TOO LOW THOUGH SINCE SHORT-TERM 
MODELS INDICATE A LITTLE WARM-AIR ADVECTION TOWARD MORNING THAT WILL 
SLOW THE DROP IN TEMPERATURE. 

SOME PATCHY LIGHT FOG WILL BE POSSIBLE ACROSS THE SOUTH AND EAST 
OVERNIGHT...BUT THINK THIS WILL PREDOMINATELY BE IN RIVER VALLEYS 
AND OTHER LOW-LYING AREAS AS IS ALREADY DISPLAYED IN THE GRIDS.

.SHORT TERM (TONIGHT AND TUESDAY)...

SURFACE HIGH PRESSURE OVER OKLAHOMA WILL CONTINUE TO MOVE EASTWARD 
AND BUILD OVER THE OHIO VALLEY TONIGHT INTO TUESDAY. SKIES WILL 
BEGIN CLEARING FROM WEST TO EAST THIS EVENING AND TEMPERATURES WILL 
FALL INTO THE LOW 30S. SOME PATCHY FOG WILL BE POSSIBLE IN THE 
NORMAL FOG PRONE AREAS ACROSS SOUTH CENTRAL KENTUCKY WHERE MORE 
PRECIPITATION FELL OVERNIGHT. 

ON TUESDAY...A RIDGE WILL BUILD OVER THE REGION AND SKIES SHOULD 
REMAIN MOSTLY CLEAR WITH DAYTIME HIGHS WARMING BACK INTO THE LOW TO 
MID 50S. SOUTHWEST WINDS WILL BE SOUTHEASTERLY AHEAD OF A POTENT LOW 
PRESSURE SYSTEM THAT WILL MOVE INTO THE AREA ON WEDNESDAY.

.LONG TERM (TUESDAY NIGHT - MONDAY)...

WEDNESDAY AND THURSDAY...

A COLD ARCTIC BLAST WILL BE THE BIG STORY FOR THIS FORECAST.

IN THE UPPER ATMOSPHERE A DEEP CLOSED SOUTHERN STREAM LOW WILL TRACK 
ACROSS TEXAS AND THEN BECOME ABSORBED INTO A NORTHERN STREAM TROUGH 
AS THEY MOVE ACROSS THE MISSISSIPPI VALLEY. THE RESULT WILL BE A 
DEEPENING SURFACE LOW THAT WILL TRACK NORTHEAST FROM LOUISIANA TO 
MICHIGAN. THE SHORT RANGE MODELS ARE IN SOME DISAGREEMENT ON THE 
TIMING AND TRACK OF THE SYSTEM WITH THE NAM A LITTLE FURTHER WEST 
THAN THE GFS. REGARDLESS... THIS SYSTEM WILL BRING RAIN INTO THE 
LOWER OHIO VALLEY DURING THE DAY WEDNESDAY AS WELL AS GUSTY WINDS. 

A STRONG COLD FRONT WILL SWEEP ACROSS THE FORECAST AREA WEDNESDAY 
NIGHT WITH WITH RAIN CHANGING TO SNOW. MOST OF THE MOISTURE WILL BE 
OUT OF THE AREA BY THE TIME THE CHANGE OVER OCCURS AND THE GROUND 
WILL BE FAIRLY WARM SO NO SNOW ACCUMULATION IS EXPECTED WEDNESDAY 
NIGHT. 

COLD AIR WILL CONTINUE TO ADVECT INTO THE REGION DURING THE DAY 
THURSDAY. SKIES WILL REMAIN CLOUDY AND LIGHT SNOW SHOWERS WILL BE 
NOTED AS THE COLD AIR SQUEEZES THE RESIDUAL MOISTURE OUT OF THE 
AIRMASS. 

TEMPERATURES WEDNESDAY WILL WARM INTO INTO THE UPPER 40S EVEN WITH 
THE CLOUD COVER AND RAIN. LOWS WEDNESDAY NIGHT WILL FALL INTO THE 
LOWER 30S AND WILL HAVE A HARD TIME REACHING THE UPPER 30S DURING 
THE AFTERNOON. 
  

FRIDAY THROUGH MONDAY...

A DEEP TROUGH WILL REMAIN IN PLACE ACROSS THE GREAT LAKES AND OHIO 
VALLEY FOR MUCH OF THE WEEKEND. DRY WEATHER IS EXPECTED BUT 
TEMPERATURES FRIDAY AND SATURDAY WILL BE SOME 10 TO 15 DEGREES BELOW 
NORMAL FOR EARLY DECEMBER. SOME WARMER AIR WILL BEGIN TO ADVECT INTO 
THE REGION LATE SUNDAY AND MONDAY.

&&

.AVIATION (06Z TAF ISSUANCE)...

MOSTLY VFR CONDITIONS ARE EXPECTED OVER THE NEXT 24 HOURS. THE ONLY 
RESTRICTIONS EXPECTED WILL BE FROM 06-14Z FROM MVFR-IFR VSBYS DUE TO 
LIGHT FOG. THE BEST CHANCE FOR THIS WILL BE AT BWG AND POSSIBLY LEX. 
IF FOG FORMS IT COULD BE FREEZING FOG SINCE TEMPS WILL HOVER AROUND 
AND JUST BELOW THE FREEZING MARK. HOWEVER A RECENT AMDAR SOUNDING 
FROM SDF SHOWS FAIRLY MODERATE WINDS JUST OFF THE SFC...10-20 KTS IN 
THE 1-3 KFT RANGE. THIS MAY HELP PRECLUDE FOG FROM FORMING...AT 
LEAST A WIDESPREAD FOG. WILL CONTINUE AN MVFR OR IFR VSBY 
RESTRICTION AT BWG FOR NOW. 

CLEAR SKIES AND SOUTHERLY WINDS FROM 4-7KTS SHOULD BE THE RULE FOR 
THE REST OF THE TAF PERIOD...THOUGH TOWARDS 06Z WED...MID TO HIGH 
LEVEL CLOUDS WILL PUSH IN FROM THE SOUTH AS WINDS BACK AROUND TO THE 
SOUTHEAST AND INCREASE.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&

$$

UPDATE.........AL
SHORT TERM.....LMS
LONG TERM......JA
AVIATION.......AL