FXUS61 KRLX 021846
AFDRLX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
128 PM EST WED DEC 2 2009
.SYNOPSIS...
STRONG LOW PRESSURE SYSTEM MOVES TO NORTHEAST TONIGHT FOLLOWED BY
HIGH PRESSURE. A WEEKEND SYSTEM MAY BRUSH THE AREA WITH
LIGHT SNOW...THEN HIGH PRESSURE IS BACK SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
MODELS IN GENERAL AGREEMENT WITH DOWN SLOPE MIN AREA OF PCPN AND DRY
SLOT MOVING IN FOR THIS AFTERNOON AND TONIGHT. WIND GRADIENTS SHIFT
TO SOUTHWEST BY AROUND 06Z AS LOW MOVES THROUGH OHIO VALLEY. STRONG
GRADIENTS AND WINDS SHOULD PERSIST TONIGHT. AS HAS BEEN THE CASE
THUS FAR THIS FALL THE UPPER FLOW CONTINUES TO MAINTAIN A WEST TO
SOUTHWEST ORIENTATION OVER OUR REGION SO WE ARE NOT ABLE TO SET UP
WITH A GOOD NORTHWEST FLOW SITUATION FOR OUR AREA BEHIND COLD
FRONTS. HAVE KEPT THE AIR COLD ENOUGH FOR SNOW OUT OF OUR AREA
UNTIL THURSDAY NIGHT.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
WITH THE LOW PRESSURE SYSTEM TO OUR EAST...LOW LEVEL FLOW BECOMES
WEST NORTHWEST THAT COMBINED WITH LINGERING MOISTURE...WILL PRODUCE
SOME UPSLOPE SNOW THURSDAY...CONTINUING THU NIGHT...AND THEN
GRADUALLY TAPERS OFF ON FRIDAY. THE ABSENCE OF CRYSTAL GROWTH ZONE
IN CLOUD WILL LIMIT SNOW ACCUMULATIONS.
MINOR CHANGES WERE NOTED TO TEMPERATURES THROUGH THE PERIOD. HIGHS
ON THURSDAY WILL BE COLDER THAN NORMAL AS H8 COLD ADVECTION
CONTINUES WITH AROUND -5C TEMPS OR LOWER REMAINING IN PLACE THRU THE
WEEKEND. GENERALLY WENT CLOSER TO THE COOLER MET.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
GFS WAS TEASING US WITH ITS 06Z RUN THIS MORNING...BRINGING A
SOUTHERN STREAM SHORTWAVE OVER REGION WITH PLENTY OF GULF MOISTURE
ON FRIDAY NIGHT AND SATURDAY...A SETUP THAT COULD HAVE BROUGHT
SEVERAL INCHES OF SYNOPTIC SNOW TO MUCH OF THE REGION.
HOWEVER...THE 12Z RUNS OF THE GFS/ECMWF/GEM DIG THE SHORTWAVE
FURTHER SOUTH INTO THE TENNESSEE VALLEY BEFORE TURNING IT NORTHEAST.
AT BEST...IT LOOKS LIKE WE MAY BE GRAZED BY THE NORTHWESTERN FRINGE
OF SYNOPTIC SNOW SHIELD...AND WOULD NOT BE SURPRISED IF TRENDS
CONTINUE AND SYSTEM MISSES US ALTOGETHER. HAVE CHANCE POPS EAST OF
THE OHIO RIVER ONLY FOR THIS SYSTEM FOR NOW...AND DO NOT THINK
SYSTEM IS WORTHY OF AN HWO MENTION.
HAVE A SHORT PERIOD OF UPSLOPE ACTIVITY IN THE NORTHERN MOUNTAINS
SATURDAY NIGHT BEHIND SYSTEM...WHILE THE LOWLANDS DRY OUT. PATTERN
THEN TRANSITIONS TO A ZONAL PATTERN ALOFT WITH HIGH PRESSURE IN
PLACE AT THE SURFACE FOR SUNDAY AND MONDAY. THE RESULT WILL BE DRY
WEATHER...OCCASIONAL BOUTS OF MID/HI CLOUDS IN FAST FLOW ALOFT...AND
TEMPERATURES MODERATING BACK TO SEASONAL LEVELS. USED HPC NUMBERS
FOR TEMPERATURES WITH SOME TWEAKING. A WEAK DISTURBANCE IN THE FLOW
MAY PRODUCE PRECIPITATION FOR TUESDAY...SO HAVE SLIGHT CHANCE POPS
IN THE GRIDS FOR THAT.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
THE WINDS WILL BE THE BIG STORY THROUGH TONIGHT...ESPECIALLY ACROSS
THE MOUNTAINS. IT WILL MAKE FOR ROUGH IN FLIGHT CONDITIONS. AS THE
LOW MOVES TO THE NORTHEAST THURSDAY THE GRADIENT WILL WEAKEN AND
WIND SPEEDS AND GUSTS DIMINISH. WITH LOW PASSING TO THE WEST OF THE
REGION WE WILL GENERALLY REMAIN IN THE MVFR REGION FOR CEILINGS INTO
TONIGHT. LACK OF A GOOD NORTHWEST FLOW SITUATION SETTING UP BEHIND
THE FRONT THE CEILING SHOULD REMAIN MVFR THURSDAY. VISIBILITIES
WILL BE PRIMARILY 5 OR GREATER WITH SOME ISOLATED 2 TO 3 MILES IN
PRECIPITATION.
AFTER 18Z THURSDAY...
IFR CONDITIONS POSSIBLE IN RAIN AND SNOW SHOWERS THURSDAY AND
THURSDAY NIGHT IN THE NORTHEAST MOUNTAINS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR WVZ033>038-046-
047.
OH...NONE.
KY...NONE.
VA...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR VAZ003-004.
&&
$$
SYNOPSIS...AAR
NEAR TERM...26
SHORT TERM...ARJ
LONG TERM...CL
AVIATION...AAR
