FXUS61 KRLX 030929
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
409 AM EST THU DEC 3 2009

.SYNOPSIS...
TEMPERATURE DROPS AS WINDS EASE TODAY WITH LOW LEVEL MOISTURE IN 
PLACE. HIGH PRESSURE POKES UP OHIO VALLEY ON FRIDAY.  SYSTEM MAY 
BRUSH AREA EARLY SATURDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
COLD FRONT WILL PASS OVER THE NEXT FEW HOURS...BRINGING ANOTHER GOOD 
BURST OF WIND AS IT DOES. STILL HAVE PLENTY OF WIND ALOFT TO BRING 
DOWN IN THIS SCENARIO...AND WILL SEE STRONG GUSTS WITH THE PASSAGE. 
WINDS ABOVE THE BOUNDARY RELAX AFTER 12Z THIS MORNING...AS DOES THE 
PRESSURE GRADIENT...WITH THE HEART OF THE SYSTEM LIFTING RAPIDLY TO 
THE NORTHEAST. SURFACE WINDS GRADUALLY TURN MORE WESTERLY TO 
NORTHWESTERLY BRINGING IN WRAP AROUND LOW LEVEL MOISTURE WHICH WILL 
LINGER FOR THE BULK OF THE NEAR TERM FORECAST PERIOD. BEST CHANCES 
FOR PRECIPITATION ARE IN THE HIGHER ELEVATIONS TODAY...PARTICULARLY 
THE NORTHEAST MOUNTAINS...BUT WILL CONTINUE THE POTENTIAL FOR A FEW 
SHOWERS CWA WIDE UNTIL EARLY AFTERNOON. SHOULD SEE A SIGNIFICANT 
DEPTH OF THE LOW LEVEL MOISTURE TO GET SOME DRIZZLE TODAY AS WELL. 
WINDS MAY MITIGATE THIS POTENTIAL SOMEWHAT. UPSLOPE SHOWERS...WHICH 
WILL TURN TO LIGHT SNOW SHOWERS OVERNIGHT FOR THE NORTHEAST 
MOUNTAINS...WILL DISSIPATE BY 12Z. NO ACCUMULATIONS ARE EXPECTED.

AS COLD AIR ADVECTION COMMENCES...FIGURE MAX TEMPERATURES WILL OCCUR 
JUST AFTER 12Z TODAY...AND WILL SLOWLY DROP DURING THE DAY.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
SFC HIGH PRESSURE GRADUALLY BUILDS FROM THE SOUTHWEST THROUGH 
SUNDAY.  HOWEVER...MODELS SHOW AND UPPER LEVEL LOW ROTATING JUST 
NORTH OF THE GREAT LAKES REGION...WITH AN EXTENDING TROUGH DEEP 
SOUTH INTO THE TEXAS BY FRIDAY. THIS TROUGH GRADUALLY MOVES EAST 
WITH AN ELONGATED VORTICITY MAX APPROACHING INTO THE OH VALLEY BY 
SATURDAY. MEANWHILE...ANOTHER SHORT WAVE DEVELOPS OVER THE GULF 
STATES AND GETS PULLED UNDER THE NORTHERN STREAM TROUGH...LIFTING 
NORTH EAST ALONG THE APPALACHIANS AND THE ATLANTIC STATES THROUGH 
SATURDAY NIGHT. 

MODELS ARE IN AGREEMENTS BRINGING QPF TO THE EASTERN HALF OF THE 
CWA. MODELS ALSO IN AGREEMENT WITH A WEST TO EAST TEMPERATURE 
GRADIENT AT H8 ROUGHLY FROM MINUS 10C TO MINUS 5C OVER OUR CWA. THIS 
COLD AIR MASS...TOGETHER WITH NEAR FREEZING SFC TEMPERATURES WILL 
ALLOW ANY LINGERING MOISTURE TO FALL IN THE FORM OF SNOW SATURDAY 
AND SATURDAY NIGHT MAINLY ALONG THE WESTERN SLOPES AND EASTERN 
MOUNTAINS. 

USED BIAS CORRECTED MAV FOR TEMPERATURES THROUGH THE PERIOD. 

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
FOLLOWED HPC IDEAS THROUGH THIS PERIOD.  THEY USED A 
MULTI-MODEL/ENSEMBLE BLEND TO ACCOUNT FOR STRENGTH/TIMING 
DIFFERENCES.  HAVE A SHORT PERIOD OF UPSLOPE SNOW SHOWERS ON THE 
BACK SIDE ON SATURDAY NIGHT...BUT THESE SHOULD END QUICKLY AS 
MOISTURE COLLAPSES QUICKLY AHEAD OF APPROACHING HIGH. EXPECT CLOUDS 
TO DECREASE THEREAFTER.

SURFACE HIGH REMAINS IN CONTROL FOR SUNDAY/MONDAY...WITH ZONAL FLOW 
ALOFT.  THIS PATTERN WILL PROMOTE A MODERATION IN 
TEMPERATURES...EVEN THOUGH VALUES WILL REMAIN A BIT BELOW NORMAL.  
ALSO FORESEE BOUTS OF MID/HI CLOUDS IN THE FAST FLOW ALOFT...BUT 
KEEPING DRY POPS.

SYSTEM THEN EJECTS FROM THE ROCKIES ON TUESDAY AND HEADS FOR THE 
OHIO VALLEY ON WEDNESDAY.  COULD SEE SOME WARM ADVECTION-DRIVEN 
PRECIPITATION ON TUESDAY BEFORE MAIN LOW CENTER APPROACHES ON 
WEDNESDAY.  PRECIP TYPE STILL IN QUESTION ON THE FRONT SIDE AT 
LEAST...KEPT A RAIN/SNOW POSSIBILITY.  TEMPERATURES FOLLOW HPC 
NUMBERS WITH TWEAKS.

&&

.AVIATION /09Z THURSDAY THROUGH MONDAY/...
STRONG WINDS WILL CONTINUE THROUGH THE REMAINDER OF TONIGHT AND 
DIMINISH INTO THURSDAY AFTERNOON. LOW LEVEL CLOUDS LOOK TO REMAIN 
WITH THE WESTERLY FLOW...SO LOW END MVFR CAN BE EXPECTED. VISIBILITY 
RESTRICTIONS ARE NOT EXPECTED WITH THE WIND A FACTOR...ALTHOUGH SOME 
DRIZZLE MAY OCCUR WITH THE ABUNDANT LOW LEVEL MOISTURE.   

AFTER 06Z FRIDAY...
IFR CONDITIONS POSSIBLE IN THURSDAY NIGHT OVER MOUNTAINOUS COUNTIES
IN LOW CLOUDS AND LIGHT MIXED PRECIPITATION. 

IFR POSSIBLE AGAIN IN LIGHT SNOW LATE FRIDAY NIGHT INTO SATURDAY 
MORNING OVER THE MOUNTAINS.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...26/ARJ
NEAR TERM...26
SHORT TERM...ARJ
LONG TERM...CL
AVIATION...26