770
FXUS61 KRNK 200058
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
758 PM EST THU DEC 19 2024
SYNOPSIS
LOW PRESSURE OVER THE UPPER MISSISSIPPI VALLEY WILL SWEEP ACROSS
THE OHIO VALLEY ON FRIDAY THEN OFF THE NEW ENGLAND COAST BY
SATURDAY BRINGING SNOW TO THE MOUNTAINS. COLDER TEMPERATURES
WITH HIGH PRESSURE FOLLOW FOR THE WEEKEND. TEMPERATURES WARM ON
MONDAY AND TUESDAY AHEAD OF LOW PRESSURE OVER THE SOUTHERN
PLAINS.
NEAR TERM /THROUGH FRIDAY/
AS OF 730 PM EST THURSDAY...
KEY MESSAGES:
1) WINTER WEATHER ADVISORIES ISSUED FOR THE MOUNTAINS OF SE WV,
SW VA, AND NW NC FOR SNOW AND GUSTY WINDS.
2) ELSEWHERE WEST OF THE BLUE RIDGE, EXPECT MAINLY RAIN, WITH
THE PIEDMONT STAYING MOSTLY DRY.
MADE A FEW ADJUSTMENTS TO TEMPERATURES FOR THE OVERNIGHT BASED
ON THE OVERCAST CLOUD COVER ACROSS THE AREA. AREAS OF STRATUS
HAD ENCROACHED FROM BOTH THE WNW AND THE SW THIS EVENING. A
WEDGE OF HIGH PRESSURE OVER THE NE COUNTIES OF VA WILL WEAKEN
TOMORROW MORNING AS 1. LOW PRESSURE MOVES OUT OF THE OH VALLEY,
AND 2. LOW PRESSURE OFF THE MID ATLANTIC COAST ORGANIZES. THIS
WILL ALLOW FOR PRECIPITATION TO DEVELOP AS A SHORT WAVE DIPS
INTO THE MID ATLANTIC REGION.
THE HIGHEST AMOUNTS OF SNOW WILL BE IN THE 2 TO 4 INCH RANGE
FOR OUR HIGHER PEAKS, AND MODELS ARE INDICATING AN AREA WEST OF
A LINE FROM LEWISBURG, TO BURKE'S GARDEN, TO BOONE TO HAVE THE
BEST CHANCE FOR +1 INCH OF SNOW. LOWER ELEVATIONS IN THE
MOUNTAINS WILL SEE MOSTLY LIGHT RAIN WITH SOME SNOW POSSIBLY
MIXING IN TOWARDS FRIDAY EVENING.
A COUPLE THINGS TO NOTE, MOISTURE WILL BE LIMITED DUE TO THE
LOW MOVING UP THE EASTERN SEABOARD, ROBBING US OF SOME QPF.
ADDITIONALLY, THE WIND TRAJECTORY IS MORE WESTERLY UNTIL THE
COLD FRONT PUSHES THROUGH TOMORROW LATE, NOT PROVIDING THE BEST
ANGLE FOR UPSLOPE SNOW DURING THE DAY. THE UPPER TROUGH DIGS SO
DEEP THAT THE STRONGEST PART OF THE SHORT WAVE MAY MISS US TO
THE SW, BUT WE SHOULD STILL HAVE ENOUGH LIFT FOR ACCUMULATIONS
IN THE WESTERN MOUNTAINS.
CONFIDENCE IN ACCUMULATING SNOW IS HIGH FOR THE WESTERN
MOUNTAINS. CONFIDENCE IN THE REST OF THE AREA SEEING MUCH
PRECIPITATION THROUGH SATURDAY IS LOW.
AS OF 120 PM EST THURSDAY...
KEY MESSAGES:
- CLIPPER WILL BRING SNOW TO THE MOUNTAINS STARTING FRIDAY
AFTERNOON
ROBUST SHORT WAVE AND SURFACE LOW PRESSURE SYSTEM OVER THE UPPER
MISSISSIPPI VALLEY WILL REACH THE MID ATLANTIC REGION ON FRIDAY.
CLOUD COVER FILLS IN THIS EVENING AND OVERNIGHT. ISOLATED TO
SCATTERED LIGHT RAIN AND SNOW SHOWERS ARE EXPECTED TO CROSS THE
AREA FRIDAY MORNING WITH LITTLE IMPACT. THE MORE ORGANIZED AREA
OF SNOW WILL REMAIN CONFINED TO THE MOUNTAINS. HRRR AND FV3
MODELS SHOW ABOUT A SIX HOUR PERIOD OF MODERATE SNOW FRIDAY
AFTERNOON AND EVENING BEFORE THE PRECIPITATION BECOMES PRIMARILY
UPSLOPE DRIVEN OVERNIGHT. PROBABILISTIC GUIDANCE MAINTAINS UP
TO 40 PERCENT PROBABILITY OF 2 INCHES OF SNOW BY FRIDAY EVENING,
WITH THE HIGHEST POTENTIAL FROM TAZEWELL COUNTY THROUGH WESTERN
GREENBRIER COUNTY.
THE SURFACE COLD FRONT CROSSES THROUGH THE AREA ON FRIDAY WITH
THE WIND BECOMING NORTHWEST AND THE COLD AIR ADVECTION
BECOMING STRONGER BY FRIDAY AFTERNOON. SIMILAR TO CONDITIONS
THURSDAY MORNING, TEMPERATURES WILL ONLY SEE MINIMAL WARMING ON
FRIDAY DUE TO ALL THE CLOUDS. NOT MUCH DEVIATION FROM GUIDANCE
NEEDED FOR LOWS TONIGHT.
SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/
AS OF 300 PM EST THURSDAY...
KEY POINTS:
1) AREAS WEST OF THE BLUE RIDGE WILL SEE SCATTERED SNOW SHOWERS
FRIDAY AFTERNOON THROUGH MIDDAY SATURDAY.
2) MUCH COLDER AIR WILL MOVE INTO THE REGION, KEEPING TEMPERATURES
WELL BELOW AVERAGE THROUGH THE PERIOD.
AS THE AXIS OF AN UPPER-LEVEL TROUGH MOVES ACROSS THE AREA
FRIDAY EVENING, SNOW SHOWERS WILL PERSIST THROUGH THE
OVERNIGHT ALONG AND WEST OF THE BLUE RIDGE AS NORTHWESTERLY FLOW
WILL CAUSE OROGRAPHIC LIFTING. EAST OF THE BLUE RIDGE, ISOLATED
SHOWERS MAY BRING A TRACE OF RAIN TO PARTS OF THE PIEDMONT, BUT
MOSTLY DRY CONDITIONS WILL CONTINUE. SNOW ACCUMULATIONS HAVE
TRENDED UP SINCE YESTERDAY, ESPECIALLY FOR THE NC/VA MOUNTAINS,
WHERE 1-2" IS EXPECTED WITH THE HIGHER ELEVATIONS SEEING 2-4".
THE SAME CAN BE EXPECTED FOR SUMMERS AND MERCER COUNTIES IN WV.
WESTERN GREENBRIER COUNTY IN WV WILL SEE THE HIGHEST
ACCUMULATIONS, AROUND 3-5" AND POSSIBLY UP TO 6". ALONG THE BLUE
RIDGE, LITTLE ACCUMULATION IS EXPECTED WITH A TRACE TO A FEW
HUNDREDTHS EXPECTED.
THE SNOW SHOWERS CONTINUE THROUGH MIDDAY SATURDAY BEFORE THE
TROUGH MOVES OFF TO THE EAST, WITH DRIER AIR FILLING IN WHICH
WILL SHUT OFF THE SNOW SHOWERS. SATURDAY WILL BE BREEZY,
ESPECIALLY ALONG THE BLUE RIDGE, WITH WIND GUSTS OVER 35 MPH
BEFORE REDUCING SATURDAY NIGHT. SATURDAY NIGHT INTO SUNDAY AND
MONDAY WILL BE VERY QUIET, AS A LARGE HIGH PRESSURE SYSTEM OVER
THE NORTHEASTERN US WILL DOMINATE THE WEATHER PATTERN FOR
SEVERAL DAYS, SLIGHTLY WEDGING THE RNK CWA IN THROUGH TUESDAY.
TEMPERATURES WILL REMAIN WELL BELOW AVERAGE THROUGH THE WEEKEND,
WITH HIGHS IN THE 30S AND 40S, WITH HIGHER ELEVATIONS REMAINING
IN THE UPPER 20S. MONDAY'S HIGHS WILL BE IN THE 30S AREA-WIDE.
LOW TEMPERATURES WILL BE IN THE 20S SATURDAY MORNING BEFORE
FALLING INTO THE TEENS AND 20S SUNDAY AND MONDAY MORNING. A FEW
SINGLE DIGIT LOWS WILL BE POSSIBLE SUNDAY MORNING IN THE HIGHEST
ELEVATIONS. WINDS WILL REMAIN LIGHT DURING THE COLDEST PERIOD,
WITH WIND CHILL NOT BEING A HAZARD.
LONG TERM /MONDAY THROUGH THURSDAY/
AS OF 300 PM EST THURSDAY...
KEY POINTS:
1) TEMPERATURES REBOUND TO NEAR NORMAL FOR THE ENTIRE PERIOD.
2) QUIET WEATHER WILL CONTINUE UNTIL LATE ON CHRISTMAS DAY, WHEN
ANOTHER SYSTEM MOVES INTO THE AREA.
HIGH PRESSURE WILL CONTINUE TO CONTROL THE WEATHER PATTERN FOR
CHRISTMAS EVE AND PART OF CHRISTMAS DAY, WITH DRY WEATHER
PERSISTING. 500MB HEIGHTS WILL CONTINUE TO SLOWLY RISE, WHICH
WILL ALLOW TEMPERATURES TO RETURN TO AROUND NORMAL. EARLY
CHRISTMAS MORNING, A STRAY RAIN SHOWER MAY MOVE INTO THE
PIEDMONT AS HIGH PRESSURE BACKS OUT TO THE NORTHEAST, WITH A
WARM SOUTHERLY FLOW BRINGING MOISTURE BACK INTO OUR AREA. A FEW
LOCATIONS MAY INITIALLY SEE RAIN MIXED WITH SNOW IN THE WV/VA
HIGHLANDS, BUT WILL QUICKLY TURN TO RAIN. MODELS DO NOT AGREE ON
WHETHER THIS WILL OCCUR, THEREFORE CONFIDENCE IS LOW AND POPS
ARE ALSO KEPT LOW, AROUND 20%. AS A LOW DEVELOPS ACROSS THE
MISSISSIPPI VALLEY AND MOVES EAST, IT WILL BEGIN TO WEAKEN AS IT
APPROACHES. MOST LOCATIONS WILL RECEIVE RAINFALL FROM THIS
SYSTEM AS IT ARRIVES LATE ON CHRISTMAS DAY OVERNIGHT INTO
THURSDAY. MODELS AGAIN DISAGREE ON THE STRENGTH OF THE SYSTEM,
WITH THE ECMWF HAVING VERY SCATTERED PRECIPITATION ACROSS THE
CWA, WHILE THE GFS HAS MORE WIDESPREAD RAINFALL. NONETHELESS,
RAIN SHOWERS WILL CONTINUE THROUGH THE END OF THE PERIOD.
TEMPERATURES REBOUND NICELY MIDWEEK, WITH HIGHS IN THE 40S,
RISING FURTHER INTO THE 40S AND 50S LATE WEEK. LOW TEMPERATURES
WILL ALSO SLOWLY RISE MID TO LATE WEEK WITH 20S ON TUESDAY
MORNING RISING INTO THE MID 30S BY THURSDAY MORNING.
AVIATION /00Z FRIDAY THROUGH TUESDAY/
AS OF 700 PM EST THURSDAY...
A MIX OF MVFR AND VFR STRATUS WAS CURRENTLY OVER THE REGION,
WITH SOME MID AND HIGH CLOUDS ALSO IN THE AREA. EXPECT LOWER
MVFR CONDITIONS TO DEVELOP OVERNIGHT INTO EARLY TOMORROW MORNING
FOR ROA, LYH, AND DAN, WITH RAIN DEVELOPING TOMORROW AFTERNOON.
BLF AND LWB WILL SEE IFR/LIFR CONDITIONS AT TIMES, AND ARE MORE
LIKELY TO SEE A CHANGEOVER TO SN IN THE AFTERNOON. ELSEWHERE,
RAIN/SNOW CHANCES WILL DIMINISH IN THE EVENING. A COLD FRONTAL
PASSAGE WILL BRING GUSTY WNW WINDS TO THE BEGINNING TOMORROW
AFTERNOON INTO SATURDAY, WITH GUSTS IN THE 20 TO 30 KTS RANGE,
EXCEPT FOR DAN AND LYH WHICH WILL BE LIGHTER.
EXTENDED AVIATION OUTLOOK...
-SHSN CHANCES CONTINUE FOR BLF AND LWB INTO SATURDAY MORNING,
AND COULD DROP VSBYS AS LOW AS IFR. THE MOUNTAINS RETURN TO VFR
FOR SUNDAY MORNING.
DRY AND WARMER VFR CONDITIONS ARE EXPECTED MONDAY AND TUESDAY.
RNK WATCHES/WARNINGS/ADVISORIES
VA...WINTER WEATHER ADVISORY FROM 1 PM FRIDAY TO 1 PM EST SATURDAY
FOR VAZ007-009-015.
NC...WINTER WEATHER ADVISORY FROM 1 PM FRIDAY TO 1 PM EST SATURDAY
FOR NCZ001-018.
WV...WINTER WEATHER ADVISORY FROM 1 PM FRIDAY TO 1 PM EST SATURDAY
FOR WVZ042-043-508.
SYNOPSIS...AMS
NEAR TERM...AMS/SH
SHORT TERM...JCB
LONG TERM...JCB
AVIATION...SH
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