FXUS63 KPAH 031130
AFDPAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PADUCAH KY
530 AM CST THU DEC 3 2009

.UPDATE...
REFRESHED THE 12Z THURSDAY ROUTINE TAF DISCUSSION. NO ADJUSTMENTS
MADE TO PUBLIC DISCUSSION SECTION.

&&

.DISCUSSION...
/PREVIOUSLY TRANSMITTED AT 340 AM CST THU DEC 3 2009/
MAIN CONCERNS ARE TIMING OF CLEARING THROUGH THE REGION AND HIGHS
TODAY. ATTENTION THEN TURNS TO POTENTIAL FOR LIGHT SNOW/FLURRIES
IN THE KHOP AREA LATE FRIDAY NIGHT AND EARLY SATURDAY MORNING.
FINALLY...POP POTENTIAL SUNDAY NIGHT WILL BE ADDRESSED.

SATELLITE IMAGERY SHOWS A HOLE IN THE OVERCAST FROM THE KSTL AREA 
SOUTHWARD INTO PORTIONS OF SOUTHEAST MISSOURI AT THIS TIME. 
BLOOMFIELD PROFILER INDICATING THAT THE LOW-LEVEL FLOW IS GENERALLY 
FROM THE NORTH...SO WOULD NOT EXPECT A DRAMATIC WEST TO EAST 
CLEARING THROUGH SUNRISE. TRIED TO FOLLOW THE IDEA ADVERTISED BY THE 
00Z NAM AND GFS. WILL HOLD THE LOW CLOUDS OVER MUCH OF THE AREA THIS 
MORNING AND THEN CLEAR THINGS OUT FROM WEST TO EAST THIS AFTERNOON. 
FOR HIGHS GENERALLY STAYED CLOSER TO THE COOLER MET GUIDANCE...AND 
EVEN UNDERCUT IT IN THE EAST WHERE SUNSHINE WILL BE SCARCE UNTIL 
LATE.

SURFACE HIGH PRESSURE WILL BUILD OVER THE REGION THROUGH 
TONIGHT...BEFORE SETTLING OVER THE AREA FRIDAY AND FRIDAY NIGHT. FOR 
TEMPERATURES...CONTINUED TO LEAN TOWARD THE CONSIDERABLY COOLER MET 
GUIDANCE TONIGHT AND FRIDAY.

ALOFT...THE SOUTHERN END OF THE MID/UPPER-LEVEL TROUGH WILL PIVOT 
THROUGH THE AREA LATE FRIDAY NIGHT AND SATURDAY NIGHT. IT WILL TRY 
TO DRAW MOISTURE NORTHWEST TOWARD THE SOUTHERN PENNYRILE REGION OF 
WEST KENTUCKY. WITH THE COLD AND DRY SURFACE HIGH OVER THE 
REGION...IT SEEMS IMPROBABLE THAT PRECIPITATION COULD REACH THE 
GROUND. 

HOWEVER...THE 00Z GFS NEARLY SATURATES THE KHOP AREA THROUGH THE 
DEPTH OF THE TROPOSPHERE...WITH JUST SOME SLIGHTLY UNSATURATED 
CONDITIONS BELOW 850MB. THE 00Z ECMWF SPITS OUT SOME VERY LIGHT 
QPF RIGHT UP TO THE KY/TN BORDER...AND THE 03Z SREF IS EVEN HINTING 
AT A SLIGHT CHANCE POP NEAR KHOP. THE MAV AND TO A LESSER EXTENT THE 
MET GUIDANCE SUPPORT A SLIGHT CHANCE POP AT KHOP. 

COULD NOT DRUM UP ENOUGH SUPPORT FROM MY NEIGHBORS TO INTRODUCE A 20 
POP FOR LIGHT SNOW TO THE SOUTHEAST OF A MURRAY TO GREENVILLE 
KENTUCKY LINE. BUT WILL MENTION A CHANCE OF FLURRIES THERE FROM 06Z 
TO 18Z SATURDAY TO HINT AT THE POTENTIAL. ANY PRECIPITATION WILL 
DEFINITELY BE IN THE FORM OF SNOW. ALSO INCREASED CLOUD COVER OVER 
THE SOUTHEAST HALF OF THE AREA...AND BUMPED UP LOWS FRIDAY 
NIGHT...AND HELD HIGHS DOWN A BIT IN THE EAST SATURDAY.

DID NOT WANT TO PLAY WITH THE LATTER HALF OF THE WEEKEND AND EARLY 
NEXT WEEK...BUT THE 00Z ECMWF AND GFS BRING AN UPPER LEVEL SYSTEM 
AND A WEAK SURFACE REFLECTION EASTWARD THROUGH THE REGION SUNDAY 
NIGHT. IT IS RELATIVELY WEAK AND MOISTURE WILL BE LACKING...BUT THE 
MODELS ARE GENERATING SOME MODEST QPF...SO DECIDED TO GO WITH THE 
FLOW AND INSERT A SLIGHT CHANCE OF SNOW OR RAIN THROUGHOUT THE 
FORECAST AREA SUNDAY NIGHT. 

&&

.AVIATION...
EASTWARD TRANSLATION OF CLEARING LINE WILL CONTINUE TODAY...WITH
KPAH CLEARING AROUND 18Z THURSDAY...KEVV AT 01Z-02Z FRIDAY AND KOWB
AROUND 03-04Z FRIDAY. AT KPAH...KEVV...KOWB...THE TRANSITION WILL
BE FROM LOW TO HIGH MVFR CEILINGS...THEN VFR CONDITIONS FOR THE
REMAINDER OF THE FORECAST PERIOD. THE CLEARING MAY ACCELERATE THIS
AFTERNOON ACROSS SOUTHWEST INDIANA/NORTHWEST KENTUCKY SHOULD THE
CLOUD LAYER MIX OUT LESS THAN 1500 FT THICK BY MIDDAY.
UNFORTUNATELY...PIREPS OVER INDIANA STILL SHOW THE CLOUD LAYER
DEPTH BETWEEN 3.5-4.0KFT THICK...SO CLEARING IS EXPECTED TO BE SLOW.
SURFACE WINDS WILL REMAIN IN THE 270-330 DEGREE QUADRANT FOR MOST
OF THE DAY.

&&

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

$$

SMITH