FXUS63 KPAH 270513
AFDPAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
1113 PM CST THU NOV 26 2009

.UPDATE...
UPDATED FOR THE 06Z TAF ISSUANCE.

&&

.DISCUSSION...
SHORT TERM... /TONIGHT THROUGH SUNDAY/
MAIN CONCERNS ARE TEMPERATURES THROUGH SATURDAY...AND THEN ATTENTION 
TURNS TOWARD INCREASING MOISTURE AND POPS HEADING INTO SUNDAY.

LAST OF LIGHT RAIN STREAMING SOUTHEAST ACROSS FAR NORTHEAST ZONES AT 
THIS TIME. THIS SHOULD CLEAR THE REGION BY 00Z...SO NO POPS IN THE 
FORECAST FOR TONIGHT. WINDS HAVE BEEN WEAKER THAN ADVERTISED 
TODAY...AND SHOULD DROP OFF SIGNIFICANTLY WITH SUNSET OVER MUCH OF 
THE AREA. THE CLEARING LINE IS RIGHT ON THE MISSISSIPPI RIVER...AND 
MAKING SOME EASTWARD PROGRESS. STILL FEEL THAT THE LOW CLOUDS WILL 
LINGER AT LEAST OVER THE NORTHEAST...IF NOT THE PENNYRILE 
REGION...THROUGH THE EVENING. GENERALLY WENT WITH CONSENSUS GUIDANCE 
FOR LOWS TONIGHT.

THE 12Z MODELS ARE IN GOOD AGREEMENT IN DROPPING THE SURFACE HIGH 
OVER THE GULF COAST...RESULTING IN SOUTHERLY RETURN FLOW DEVELOPING 
FRIDAY AND INCREASING SATURDAY AND SATURDAY NIGHT. MOSTLY CLEAR 
SKIES SHOULD PREVAIL FRIDAY THROUGH SATURDAY. GENERALLY FAVORED THE 
MILDER MAV NUMBERS DURING THIS PERIOD.

CONSENSUS OF MODELS IS TO INCREASE CLOUDS OVER THE AREA QUICKLY 
SATURDAY NIGHT WITH CEILINGS OVER MUCH OF THE AREA BY 12Z SUNDAY. DO 
NOT FEEL THERE WILL BE ENOUGH LIFT SATURDAY NIGHT TO INTRODUCE A 
POP. HOWEVER...WITH INCREASING CLOUDS...AND STOUT SOUTH TO SOUTHWEST 
WINDS...IT SHOULD BE A MILD NIGHT...WITH THE POTENTIAL FOR SOME 
AREAS TO STAY IN THE 50S THROUGH THE NIGHT. WENT A BIT ABOVE THE 
MILDER MAV FOR LOWS.

THE 12Z MODELS GENERALLY ARE A BIT FASTER WITH THE FRONT...BRINGING 
IT WELL INTO THE REGION BY THE END OF THE DAY SUNDAY. SPED IT UP 
SOME...GENERALLY FOLLOWING THE SREF FOR WINDS. THE MODELS...WITH THE 
EXCEPTION OF THE GFS...ALL GENERATE PATCHES OF LIGHT RAIN DURING THE 
DAY SUNDAY. THE GFS HAS MORE OF A PUSH WITH THE FRONT AND THEREFORE 
GENERATES MORE SIGNIFICANT QPF BEHIND THE FRONT WELL INTO THE AREA 
BY 00Z MONDAY. DECIDED TO KEEP POPS AT 30 PERCENT FOR THE ENTIRE 
AREA FOR NOW.

LONG TERM... /SUNDAY NIGHT THROUGH THURSDAY/
WITH THE APPROACH OF THE LONGWAVE TROUGH...A COLD FRONT WILL 
PROGRESS EAST ACROSS THE FORECAST AREA SUNDAY NIGHT. BOTH THE GFS 
AND ECMWF HAVE INDICATED HIGH PROBABILITIES FOR PRECIPITATION DURING 
THIS TIME...SO WE DECIDED TO RAISE POPS TO CATEGORICAL SUNDAY NIGHT. 
THE MORE PROGRESSIVE EASTWARD SHIFT OF THE FRONT AND ASSOCIATED 
PRECIPITATION IS STILL PRESENT IN THE LATEST MODEL DATA...SO WE 
EXPECT RAIN TO QUICKLY SHIFT EAST OF THE AREA DURING THE DAY MONDAY. 
AS HIGH PRESSURE BUILDS ACROSS THE AREA...TUESDAY WILL BE DRY AND 
MOSTLY SUNNY...ALBEIT RATHER COOL AS HIGHS REMAIN IN THE 40S.

LAST FEW RUNS OF THE ECMWF AND GFS SEEM TO BE COMING INTO BETTER 
AGREEMENT ON NEXT WEEK/S SPLIT FLOW PATTERN. AS THE NORTHERN STREAM 
TROUGH MOVES EAST EARLY IN THE WEEK...A CLOSED LOW WILL BE LEFT 
BEHIND OVER THE SOUTHWESTERN STATES. THIS LOW WILL EJECT EASTWARD 
INTO THE LOWER MISSISSIPPI VALLEY BY WEDNESDAY...BECOMING AN OPEN 
WAVE AS IT CONTINUES ITS MOVEMENT TOWARDS THE EAST COAST THURSDAY. 
THE EXACT TRACK OF THE LOW IS STILL IN QUESTION...AS IS THE AMOUNT 
OF MOISTURE THAT WILL EVENTUALLY MAKE IT BACK INTO THE REGION AHEAD 
OF ITS APPROACH. GIVEN THE SOMEWHAT BETTER CONTINUITY AMONG THE GFS 
AND ECMWF...WE DECIDED TO INTRODUCE SMALL CHANCE POPS TO THE 
WEDNESDAY AND WEDNESDAY NIGHT PERIODS. A RETURN TO DRY CONDITIONS 
WILL FOLLOW BEHIND THE DEPARTING SYSTEM ON THURSDAY.

&&

.AVIATION...
MVFR CEILINGS SHOULD BE CLEAR OF THE KEVV AND KOWB SITES BY 06Z.
ASIDE FROM A FEW HIGH CLOUDS STREAMING ACROSS THE REGION...SKIES
SHOULD BE CLEAR AT ALL SITES FOR THE MOST PART THROUGH THE
PERIOD. A 5-8KT WEST TO SOUTHWEST WIND SHOULD PREVAIL FOR THE
REMAINDER OF THE PERIOD.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
MO...NONE.
IL...NONE.
IN...NONE.
&&

$$

JAP/CW