446
FXUS61 KRNK 172108 CCA
AFDRNK
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE BLACKSBURG VA
408 PM EST TUE DEC 17 2024
SYNOPSIS
A FAIRLY UNSETTLED WEATHER PATTERN WILL LEAD TO WARM
TEMPERATURES AGAIN ON WEDNESDAY, ALONG WITH INCREASING RAIN
CHANCES WITH ANOTHER COLD FRONT PUSHING THROUGH THE REGION.
TEMPERATURES GRADUALLY COOL THROUGH THE END OF THE WORK WEEK, AND
INTO THE WEEKEND. UPSLOPE SNOW SHOWERS WILL BE POSSIBLE FRIDAY
NIGHT INTO SATURDAY ACROSS EASTERN WEST VIRGINIA.
NEAR TERM /THROUGH TONIGHT/
AS OF 230 PM EST TUESDAY...
KEY MESSAGE:
1) COLD FRONT STALLS ACROSS THE AREA AND LIFTS NORTH AS A WARM
FRONT TONIGHT.
2) WIDESPREAD RAINFALL RETURNS TO THE AREA WEDNESDAY EVENING
FIRST ACROSS WEST VIRGINIA BEFORE PROGRESSING EAST INTO VIRGINIA
BY THE LATE EVENING HOURS.
3) PATCHY TO AREAS OF DENSE FOG WILL BE POSSIBLE AGAIN ACROSS
PORTIONS OF SW VIRGINIA AND NW NORTH CAROLINA OVERNIGHT TONIGHT
AS THE WARM FRONT LIFTS NORTH.
AN UPPER LEVEL SHORTWAVE DIGGING SOUTHEASTWARD ACROSS THE
CENTRAL PLAINS TONIGHT WILL AID IN IN UPPER LEVEL FORCING FOR
ASCENT ACROSS THE REGION LATE WEDNESDAY AS IT CONTINUES TO DIG
SOUTH, AND BECOMES NEGATIVELY TILTED. AS THE TROUGHS AXIS
BECOMES NEGATIVELY TILTED FROM LOUISIANA TOWARDS WESTERN NEW
YORK, SURFACE CYCLOGENESIS LOOKS TO DEVELOP ALONG THE STALLED
COLD FRONT THAT HAS REMAINED OVER THE REGION TODAY. WHILE
PRESSURE FALLS DON'T LOOK TO BE EXTREMELY IMPRESSIVE, THE
INTEGRATED WATER VAPOR TRANSPORT LOOKS TO REACH MODEST LEVELS
OF AROUND 500 KG/M/S. THIS LOOKS TO BRING 0.25-0.5 INCHES OF
RAINFALL FOR AREAS WEST OF THE BLUE RIDGE, AND AROUND 0.1-0.15
INCHES OF RAINFALL FOR AREAS EAST OF THE BLUE RIDGE. TONIGHT AS
THE STALLED FRONT THAT HAS REMAINED OVER THE VA/NC BORDER TODAY
LIFTS NORTH, SOME PATCHY DENSE FOG CAN'T BE RULED OUT ACROSS
PORTIONS OF SW VIRGINIA AND NW NORTH CAROLINA. THIS MAY
NECESSITATE A DENSE FOG ADVISORY AGAIN IF IT BECOMES WIDESPREAD
ENOUGH. OVERALL, EXPECT ANOTHER WARM DAY ACROSS THE REGION, WITH
HIGH TEMPERATURES CLIMBING INTO THE LOW TO MID 60S ACROSS HIGHER
TERRAIN LOCATIONS, AND MID TO UPPER 60S ACROSS THE PIEDMONT.
LOWS TONIGHT WILL GENERALLY FALL INTO THE LOW TO MID 40S.
SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/
ISSUED AT 230 PM EST TUE DEC 17 2024
KEY MESSAGES:
- RAIN CONTINUES OVER MUCH OF THE AREA WEDNESDAY NIGHT.
- A TRANSITION TO UPSLOPE SNOW SHOWERS IS ANTICIPATED LATE WEDNESDAY
NIGHT, WHICH SHOULD CONTINUE INTO THURSDAY.
- ADDITIONAL UPSLOPE SNOW SHOWERS WILL BE POSSIBLE THURSDAY NIGHT
THROUGH FRIDAY NIGHT.
A FAIRLY WIDESPREAD RAIN EVENT SHOULD CONTINUE INTO WEDNESDAY NIGHT
AS A COLD FRONT CONTINUES MOVING ACROSS THE FORECAST AREA. MY
CONFIDENCE IS GOOD IN THAT WE'LL SEE RAINFALL AMOUNTS BETWEEN 0.25
IN. AND 0.5 IN. OVERALL REGION WIDE, WITH HIGHER QPF TOTALS
ANTICIPATED WEST OF THE BLUE RIDGE. ACROSS SOME OF THE HIGHER
TERRAIN IN SOUTHEAST WEST VIRGINIA, RAINFALL TOTALS APPROACHING AN
INCH MAY EVEN BE SEEN. EVEN WITH ANTECEDENT SOIL MOISTURE VALUES
AVERAGING 80-90% OF SATURATION IN SEVERAL PARTS OF OUR FORECAST
AREA, ANY FLOODING RISK SHOULD BE MINIMAL GIVEN THE STORM SYSTEM'S
SPEED.
AS WINDS BECOME NORTHWESTERLY AFTER THE FRONTAL PASSAGE, LOW-LEVEL
COLD ADVECTION WILL ALLOW THE PRECIPITATION TO MIX WITH OR BRIEFLY
CHANGE TO SNOW WEST OF THE BLUE RIDGE BEFORE ENDING. SNOWFALL
AMOUNTS WILL BE UNDER AN INCH - AND PROBABLY ONLY A COUPLE OF TENTHS
OF AN INCH - AND PRIMARILY BE LIMITED TO WESTERN GREENBRIER COUNTY.
AFTER A BRIEF RESPITE, ANOTHER DISTURBANCE/CLIPPER-TYPE SYSTEM
IS EXPECTED TO HEAD INTO OUR AREA FROM THE MIDWEST. AS THIS
FEATURE MOVES ACROSS OUR AREA, ANOTHER ROUND OF UPSLOPE SHOWERS
IS EXPECTED TO DEVELOP BY THURSDAY NIGHT AND CONTINUE THROUGH
FRIDAY. GIVEN FORECAST ENVIRONMENTAL CONDITIONS, THE
PRECIPITATION SHOULD START OUT WINTRY IN NATURE THURSDAY NIGHT
BEFORE MIXING WITH OR BECOMING RAIN FRIDAY. THEN, AS THE
ATMOSPHERE COOLS FRIDAY NIGHT, THE UPSLOPE PRECIPITATION SHOULD
CHANGE BACK OVER TO SNOW. ANY SNOWFALL TOTALS MOST LIKELY
AVERAGING A COUPLE TENTHS OF AN INCH, PRIMARILY ACROSS WESTERN
GREENBRIER COUNTY.
LONG TERM /SATURDAY THROUGH TUESDAY/
ISSUED AT 230 PM EST TUE DEC 17 2024
KEY MESSAGES:
- COLDER TEMPERATURES RETURN TO THE FORECAST AREA THIS WEEKEND.
- SOME MOUNTAIN SNOW SHOWERS WILL BE POSSIBLE EARLY IN THE WEEKEND.
THE BIG STORY IN THE DAY 4 THROUGH 7 PERIOD WILL BE THE RETURN OF
BELOW NORMAL TEMPERATURES. EVEN AFTER THE "DEPARTURE" OF THE MAIN
TROUGH AXIS, A BROAD NORTHWESTERLY FLOW ALOFT IS EXPECTED TO REMAIN
IN PLACE HEADING INTO THE UPCOMING WEEKEND. AS SUCH, WILL
TEMPERATURES AGAIN FALLING BELOW WHAT WE NORMALLY EXPECT THIS TIME
OF YEAR, AS BOUNDARY LAYER/850 HPA TEMPERATURES DROP BELOW ZERO. THE
RESULT WILL BE HIGHS LIKELY NOT MAKING IT OUT OF THE 20S AND 30S BY
SUNDAY. AND WITH A NORTHWESTERLY BREEZE LIKELY BLOWING BETWEEN 10
AND 15 MPH, IT'LL LIKELY FEEL MUCH COLDER. FORTUNATELY, AT LEAST FOR
NOW, IT DOESN'T LOOK LIKE WE'LL MEET ANY SORT OF HEADLINE THRESHOLD.
THE OTHER ITEM OF NOTE WILL BE THE CONTINUED POSSIBILITY OF SOME
SNOW SHOWERS LINGERING INTO SATURDAY. THERE'S SOME INDICATION IN
SOME OF THE DETERMINISTIC GUIDANCE THAT ADDITIONAL SHORTWAVE ENERGY
COULD MOVE ACROSS THE FORECAST AREA SATURDAY MORNING. HOWEVER, A
CLOSER LOOK AT THE CLUSTER ANALYSIS FOR THIS TIME PERIOD SUGGESTS
UNCERTAINTY IN THIS HAPPENING. GIVEN THIS, I WILL CONTINUE WITH THE
POSSIBILITY OF SOME MOUNTAIN SNOW SHOWERS -- PRIMARILY IN SOUTHEAST
WEST VIRGINIA -- AND NOT STRAY TERRIBLY FAR FROM THE MODEL BLEND.
ANY MOUNTAIN SNOW SHOWERS SHOULD END SATURDAY NIGHT, AS HIGH
PRESSURE BUILDS INTO THE REGION FOR THE REST OF THE DAY 4-7 PERIOD.
WE COULD SEE TEMPERATURES WARM A BIT (RELATIVELY SPEAKING, OF
COURSE) EARLY NEXT WEEK AS RIDGING ALOFT WORKS ITS WAY INTO THE AREA.
AVIATION /19Z TUESDAY THROUGH SUNDAY/
AS OF 1230 PM EST TUESDAY...
MVFR TO LIFR CIGS ARE BEING OBSERVED AT BCB, LWB, AND BLF THIS
AFTERNOON. EXPECT THESE SITES TO BECOME VFR THROUGH THE EVENING
AS SURFACE MIXING CLEARS OUT THE LOW CLOUD BASE. A WARM FRONT
STALLED ALONG THE VA/NC BORDER TODAY WILL LIFT NORTH THROUGHOUT
THE OVERNIGHT HOURS BRINGING RAIN CHANCES BACK INTO THE AREA.
THIS WILL ALSO RETURN LOW CIGS AND VISIBILITIES TO ALL TERMINALS
BY THE 11/12 UTC TIMEFRAME. THESE IFR TO LIFR RESTRICTIONS
LOOK TO LINGER AT ALL TERMINALS THROUGH THE END OF THE TAF
PERIOD. RAIN SHOWERS WILL ALSO BE IMPACTING ALL TERMINALS BY THE
12 UTC TIMEFRAME.
THERE IS MODERATE TO LOW CONFIDENCE IN THE VISIBILITY AND CLOUD
BASE FORECAST.
EXTENDED AVIATION OUTLOOK...
ADDITIONAL SHOWERS AND SUB-VFR CONDITIONS ARE POSSIBLE LATE
WEDNESDAY INTO THURSDAY ASSOCIATED WITH ANOTHER FRONTAL SYSTEM.
WEST TO NORTHWEST FLOW FRIDAY WITH SNOW SHOWERS IN THE
MOUNTAINS WITH SUB-VFR POSSIBLE. THESE SUB-VFR CIGS COULD
LINGER INTO LATE SATURDAY OVER THE MOUNTAINS BEFORE VFR RETURNS.
RNK WATCHES/WARNINGS/ADVISORIES
VA...NONE.
NC...NONE.
WV...NONE.
SYNOPSIS...EB
NEAR TERM...EB
SHORT TERM...DB
LONG TERM...DB
AVIATION...BMG/EB
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