809
FXUS61 KRNK 210756
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
256 AM EST THU NOV 21 2024
SYNOPSIS
A PROLONGED PERIOD OF GUSTY WINDS THROUGH SATURDAY, ALONG WITH
PERSISTENT ACCUMULATING UPSLOPE SNOW FOR THE MOUNTAINS.
TEMPERATURES WARM BY EARLY NEXT WEEK IN ADVANCE OF ANOTHER COLD
FRONT APPROACHING THE AREA THROUGH THE MIDDLE OF NEXT WEEK.
NEAR TERM /THROUGH TONIGHT/
AS OF 230 AM EST THURSDAY...
KEY MESSAGES:
1) UPSLOPE SNOW BEGINS THIS AFTERNOON AND WILL CONTINUE THROUGH
TONIGHT.
2) BELOW NORMAL TEMPERATURES TODAY.
WINDS HAVE SUBSIDED A BIT THIS MORNING AS THE INITIAL 850MB JET
ASSOCIATED WITH THE FRONTAL PASSAGE HAS RELAXED. STILL SEEING AN
OCCASIONAL 20 TO 30 MPH GUST ALONG THE HIGHER RIDGETOPS, BUT
GENERALLY LESS THE 20MPH OR LESS AWAY FROM THE HIGHER
ELEVATIONS.
MOSTLY CLEAR SKIES CONTINUE THROUGH LATE MORNING, BUT ANY
WARMING WILL BE SLOW AS COLD AIR ADVECTION WILL LIMIT ANY
HEATING, ESPECIALLY ACROSS THE MOUNTAINS. FIRST ROUND OF
MULTIPLE ROUNDS OF UPSLOPE SNOW WILL DEVELOP AND ARRIVE BY THIS
AFTERNOON ACROSS SOUTHEAST WEST VIRGINIA. SHOULD INCREASE IN
COVERAGE THROUGH THIS EVENING AS SEVERAL ROUNDS OF SNOW SQUALLS
PUSH ACROSS SOUTHWEST VIRGINIA AND SOUTHEAST WEST VIRGINIA.
MODEL SOUNDINGS INDICATE SOME VERY SMALL AMOUNTS OF INSTABILITY,
ALONG WITH STEEP LOW LEVEL LAPSE RATE UNDERNEATH A STRONG 500MB
JET THIS AFTERNOON. THIS COULD PRODUCE A FEW CONVECTIVELY
ENHANCED SNOW BANDS, POSSIBLY REACHING INTO THE I81 CORRIDOR
AND THE BLUE RIDGE SOUTH OF ROANOKE. AFTER SUNSET, SNOW BECOMES
CONFINED TO FAVORED WESTERN SLOPES WITH PERHAPS JUST A FEW
FLURRIES FURTHER EAST.
TEMPERATURES ONLY IN THE 30S FOR THE MOUNTAINS, BUT A BIT
WARMER ACROSS THE PIEDMONT WHERE LESS CLOUD COVER WILL AT LEAST
ALLOW FOR SOME HEATING IN THE AFTERNOON. THIS SHOULD ALLOW FOR
AT LEAST MID/UPPER 40S EAST OF THE BLUE RIDGE. TONIGHT, MID 20S
IN THE MOUNTAINS TO LOW 30S IN THE EAST.
SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/
AS OF 230 AM EST THURSDAY...
KEY MESSAGES:
1. WINTER STORM WARNING CONTINUES FOR WESTERN GREENBRIER COUNTY, WV
THROUGH SATURDAY. WINTER WEATHER ADVISORIES IN EFFECT FOR SOUTHEAST
WV, FAR SOUTHWEST VA AND NORTHWEST NC.
2. GUSTY WINDS, COLD
TEMPERATURES, MODERATE MOUNTAIN SNOWFALL ACCUMULATIONS EXPECTED
DURING THE END OF THE WEEK.
3. DRY AND QUIET WEATHER RETURNS SUNDAY.
A DEEP UPPER LOW WILL CONTINUE TO ROTATE OVER THE NORTHERN MID
ATLANTIC FRIDAY THROUGH SATURDAY, WITH A SHORTWAVE TRACKING THROUGH
THE CENTRAL APPALACHIANS DURING FRIDAY. THIS ADDITIONAL PUSH OF
ENERGY WILL BRING ANOTHER ROUND OF STRONG, GUSTY WINDS FRIDAY
AFTERNOON. NORTHWESTERLY 850MB WINDS WILL BE STRONGEST LATE FRIDAY
NIGHT, BETWEEN 50 TO 55 KNOTS OVER MUCH OF THE AREA. PROBABILITIES
FROM THE HREF ARE OVER 80% THAT WIND GUSTS WILL BE 45 MPH OR GREATER
BY FRIDAY EVENING FOR MANY LOCATIONS FROM THE BLUE RIDGE FOOTHILLS
AND WESTWARD, SO ADDITIONAL WIND HEADLINES WILL LIKELY BE NEEDED,
THOUGH NOTHING HAS BEEN ISSUED AT THIS TIME. IMPACTS INCLUDE DOWNED
TREES AND POWER LINES, AND ISOLATED POWER OUTAGES, ESPECIALLY OVER
FAR SOUTHWEST VA AND NORTHWEST NC, AND SOME OF SOUTHEAST WV. WITH
THE DEEP NORTHWESTERLY FLOW, UPSLOPE SNOW SHOWERS WILL CONTINUE
FRIDAY AND INTO EARLY SATURDAY MORNING. SNOW WILL START TO WIND DOWN
AND WINDS START TO LESSEN BY SATURDAY AFTERNOON, AS THE SHORTWAVE
MOVES OUT OF THE AREA, AND THE MAIN UPPER LOW TRACKING FARTHER
EASTWARD TOWARDS THE NEW ENGLAND COAST.
CONFIDENCE IS HIGH THAT THE HIGHEST SNOWFALL ACCUMULATIONS WILL BE
IN WESTERN GREENBRIER COUNTY, WV, AND SO A WINTER STORM WARNING
REMAINS IN EFFECT THROUGH SATURDAY THERE. A WINTER WEATHER ADVISORY
IS IN EFFECT FOR ELSEWHERE IN SOUTHEAST WV, FAR SOUTHWEST VA, AND
NORTHWEST NC INTO SATURDAY MORNING. THREE DAY SNOWFALL TOTALS ARE
GENERALLY BETWEEN 2 TO 4 INCHES OUTSIDE OF WESTERN GREENBRIER, UP TO
6 INCHES FOR SOME OF THE HIGHER PEAKS, LIKE MOUNT ROGERS, VA.
WESTERN GREENBRIER COULD SEE UP TO 10 INCHES THURSDAY THROUGH
SATURDAY. ACCUMULATIONS QUICKLY TAPER DOWN TO AN INCH OR LESS EAST
OF THE VA/WV BORDER, AND NO ACCUMULATIONS ARE EXPECTED EAST OF THE
BLUE RIDGE. WITH STRONG WINDS AND COLD TEMPERATURES, WIND CHILLS
WILL BE IN THE TEENS IN THE WEST AND LOW TO MID 20S IN THE EAST
FRIDAY MORNING, AND IN THE LOW TO MID 20S AREAWIDE SATURDAY MORNING.
NBM PROBABILITIES FOR TEMPERATURES LESS THAN 32 DEGREES FRIDAY
MORNING ARE OVER 70% FOR MUCH OF THE AREA, THEREFORE THINKING FRIDAY
WILL BE THE COLDEST OF THIS FORECAST PERIOD.
BY SUNDAY, THE 500MB LOW WILL BE OFF THE EASTERN CANADIAN COAST, AND
FLOW ALOFT BECOMES MORE ZONAL, WITH SOME LONG RANGE MODELS
SUGGESTING BRIEFING RIDGING DEVELOPING OVER THE EASTERN US AS
ANOTHER TROUGH DIPS SOUTHWARD INTO THE NORTHERN PLAINS. SURFACE HIGH
PRESSURE ALSO BUILDS OVERHEAD FROM THE SOUTHEASTERN STATES SUNDAY
INTO MONDAY, SO EXPECTING A RETURN TO QUIETER WEATHER AND A WARMING
TREND IN TEMPERATURES TO START THE WORK WEEK.
LONG TERM /MONDAY THROUGH WEDNESDAY/
AS OF 245 AM EST THURSDAY...
KEY MESSAGES:
1. WARMING TEMPERATURES FOR THE BEGINNING OF THE WEEK.
2. PRECIPITATION CHANCES INCREASE BY MONDAY AFTERNOON, MAINLY WEST
OF THE BLUE RIDGE.
A 500MB TROUGH DIPS SOUTHWARD INTO THE NORTHERN PLAINS BY MONDAY,
AND TRACKS TOWARDS THE GREAT LAKES AND OHIO VALLEY THROUGH THE
BEGINNING OF THE WEEK. THE ASSOCIATED SURFACE FRONT WILL REACH THE
WESTERN COUNTIES OF THE FORECAST AREA LATER MONDAY, WHICH WILL BRING
THE NEXT OPPORTUNITY FOR PRECIPITATION TO THE AREA, MAINLY FOR
AREAS WEST OF THE BLUE RIDGE. WITH TEMPERATURES REMAINING ABOVE
FREEZING, PROBABILITIES ARE HIGHEST FOR RAIN, AND LESS THAN 10%
IN THE WEST FOR ANY SNOW. THOUGH TIMING DIFFERENCES PERSIST IN
THE LONG RANGE DETERMINISTIC MODELS FOR HOW QUICKLY THIS FRONT
CROSSES THIS AREA, SURFACE HIGH PRESSURE FOLLOWS AND DRY WEATHER
LOOKS TO RETURN FOR THE MIDWEEK.
AVIATION /08Z THURSDAY THROUGH MONDAY/
AS OF 130 AM EST THURSDAY...
WIDESPREAD VFR THIS MORNING AND VFR WILL CONTINUE INTO EARLY
AFTERNOON. UPSLOPE SNOW WILL DEVELOP AFTER 18Z/1PM ACROSS THE
MOUNTAINS AND COULD IMPACT LWB/BLF THROUGH THE OVERNIGHT HOURS.
BANDS OF SNOW COULD QUICKLY REDUCE VSBY AT TIMES, PERHAPS LESS
THAN 2SM IN SOME OF THE HEAVIER BANDS. ALONG WITH PERIODS OF
REDUCED VSBY, UPSLOPE STRATUS WILL INCREASE ALONG AND WEST OF
THE BLUE RIDGE, BUT SHOULD GENERALLY BE IN THE MVFR RANGE, BUT
COULD SEE AREAS OF IFR CIGS BLF AND WEST.
WINDS TODAY WILL BE WESTERLY AND REMAIN GUSTY THROUGHOUT THE TAF
PERIOD. 15 TO 25KT GUSTS ARE LIKELY.
EXTENDED AVIATION OUTLOOK
GUSTY NORTHWEST WINDS CONTINUE THROUGH THE END OF THE WEEK.
PROLONGED PERIOD OF UPSLOPE SNOW AND SUB-VFR CIGS POSSIBLE OVER
THE MOUNTAINS. AVIATION CONDITIONS IMPROVE SUNDAY INTO MONDAY.
RNK WATCHES/WARNINGS/ADVISORIES
VA...WIND ADVISORY UNTIL 7 AM EST THIS MORNING FOR VAZ015>017-022.
WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 7 AM EST
SATURDAY FOR VAZ015.
WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM EST
SATURDAY FOR VAZ007-009.
NC...WIND ADVISORY UNTIL 7 AM EST THIS MORNING FOR NCZ001-002-018.
WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 7 AM EST
SATURDAY FOR NCZ001-018.
WV...WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM EST
SATURDAY FOR WVZ042>044-507.
WINTER STORM WARNING FROM 1 PM THIS AFTERNOON TO 7 PM EST
SATURDAY FOR WVZ508.
SYNOPSIS...BMG
NEAR TERM...BMG
SHORT TERM...AS
LONG TERM...AS
AVIATION...BMG
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