FXUS61 KRLX 230544
AFDRLX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
1240 AM EST WED DEC 23 2009
.SYNOPSIS...
HIGH PRESSURE GIVING WAY TO A LOW PRESSURE SYSTEM FOR CHRISTMAS.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
WILL UPDATE FORECAST TO INCLUDE LIGHT SNOW OCCURRING ACROSS NORTHERN
WEST VIRGINIA THIS EVENING. WILL ALSO LOWER SKY COVER IN THE SOUTH
THIS EVENING BASED ON SATELLITE...ALTHOUGH CLOUDS WILL BE PUSHING IN
FROM THE WEST LATER TONIGHT.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH FRIDAY/...
MODELS ARE GENERALLY CONSISTENT WITH TRACKING SFC LOW FURTHER WEST
AND BRINGING OCCLUDED FRONT THROUGH THE REGION DURING THE DAY ON
FRIDAY. TIMING DIFFERENCES ARE STILL PREVALENT WITH NAM BEING THE
SLOWEST AND OVERALL ALL MODELS A TAD SLOWER. SO HELD OFF ON THE
START OF PRECIP ON THURSDAY TIL LATE AFTERNOON AND BRING POPS IN
FROM SW TO NE DURING THURSDAY NIGHT AND CAT POPS ON FRIDAY. 85H
TEMPERATURES WARM AS WELL THROUGH THE PERIOD. INITIALLY TEMPERATURES
AT THE SURFACE WILL BE COLD ENOUGH IN THE EASTERN MOUNTAIN VALLEYS TO
HAVE PRECIP START OUT AS FREEZING RAIN THURSDAY NIGHT AND CONTINUE
INTO CHRISTMAS MORNING BEFORE CHANGING TO ALL RAIN. FRONTAL PASSAGE
FAIRLY QUICK AND ONLY EXPECTING 1/4 TO 1/2 INCHES OF RAIN AT THE
MOST ON THE SNOW PACK. WE WILL SEE SOME RISES IN THE RIVERS WITH
SOME SNOWMELT...BUT NOT EXPECTING ANY MAJOR PROBLEMS RIVER WISE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
PRECIPITATION WILL DECREASE IN INTENSITY AND COVERAGE FRIDAY NIGHT
AS FRONTAL BOUNDARY MOVES EAST OF THE REGION. PRECIPITATION WILL ALSO
GRADUALLY CHANGE OVER FROM RAIN TO A WINTRY MIX...THEN FINALLY TO
SNOW ACROSS ALL OF THE CWA BY SATURDAY MORNING. ANY ACCUMULATIONS
FROM SNOW SHOULD BE LIGHT AS THE BULK OF PRECIPITATION WILL HAVE
MOVED EAST OF THE REGION. LIGHT SNOW SHOWERS WILL CONTINUE OVER THE
WEEKEND AND EARLY NEXT WEEK AS THE CWA REMAINS UNDER THE INFLUENCE
OF AN UPPER LEVEL TROUGH. NORTHERN AND CENTRAL MOUNTAINS WILL SEE
THE MOST ACTIVITY DUE TO UPSLOPE ENHANCEMENT. IN
ADDITION...TEMPERATURES WILL ALSO GRADUALLY COOL THIS WEEKEND AS THE
TROUGH DEEPENS. HIGH PRESSURE BUILDS IN EARLY/MID NEXT WEEK FOR
DRIER AND SLIGHTLY WARMER WEATHER.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
TRICKY BALANCE OF FACTORS TONIGHT...WITH LOW LEVEL MOISTURE IN THE
BOUNDARY LAYER TRAPPED UNDER INVERSION...YET ALSO DRIER AIR
ATTEMPTING TO INFILTRATE IN FROM THE NORTHEAST...AROUND CENTER OF
SURFACE HIGH PRESSURE IN EASTERN GREAT LAKES. AND FINALLY...HIGHER
LEVEL CLOUDS STILL MOVING INTO THE AREA FROM THE WEST. MOST LIKELY
SCENARIO APPEARS TO BE ENOUGH LOW LEVEL MOISTURE FROM GRADUALLY
MELTING SNOW...FOR IFR VIS TO FORM IN SOME VALLEYS OF CENTRAL
LOWLANDS UNTIL ABOUT 14Z...AND ALSO IFR CIG FOR A TIME IN THE
GREENBRIER VALLEY. OTHERWISE...FOR REST OF AREA RESTRICTIONS ONLY
LIMITED TO SOME MVFR EARLY THIS MORNING. RAPID IMPROVEMENT INTO VFR
AREAWIDE AFTER 14Z...THANKS TO SLIGHTLY WARMER AIR COMBINED WITH
LOWER DEW POINTS. VFR THROUGH 06Z THURSDAY.
AFTER 06Z THURSDAY...
SYSTEM IMPACTS AREA THURSDAY NIGHT INTO FRIDAY...WITH RAIN AND
POSSIBLE IFR. FREEZING RAIN ALSO A THREAT IN THE WV MOUNTAIN
VALLEYS...AND LOW LEVEL WIND SHEAR NOT OUT OF THE QUESTION AREAWIDE
FRIDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...AAR/SL/JS
NEAR TERM...RPY
SHORT TERM...JS
LONG TERM...SL
AVIATION...MDP
