559
FXUS61 KRNK 171741
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1241 PM EST TUE DEC 17 2024
SYNOPSIS
THE WEATHER WILL REMAIN UNSETTLED WITH CLOUDS AND AN OPPORTUNITY
FOR ADDITIONAL RAIN TODAY THROUGH WEDNESDAY AS A SERIES OF UPPER
LEVEL DISTURBANCES PASSES NEAR OR OVER THE REGION. TEMPERATURES
WILL WARM THE FIRST HALF OF THE WEEK, THEN COOL BACK DOWN FOR
THE END OF THE WEEK. ANY PRECIPITATION THROUGH WEDNESDAY WILL
FALL IN THE FORM OF RAIN, THEN TRANSITION BACK TO SNOW SHOWERS
FOR THE END OF THE WEEK.
NEAR TERM /THROUGH TONIGHT/
AS OF 200 AM EST TUESDAY...
THE DENSE FOG ADVISORY WAS CANCELLED AN HOUR EARLY THIS MORNING
AS GROUND OBSERVATION AND SATELLITE OBSERVATION CONFIRMED THAT
WIDESPREAD DENSE FOG WAS NOT PRESENT ACROSS THE AREA. A FEW
LOCATIONS MAY STILL SEE PATCHY DENSE FOG OVER THE NEXT HOUR OR
TWO; HOWEVER, THIS SHOULD QUICKLY DISSIPATE ONCE TEMPERATURES
WARM UP. TEMPERATURES WERE ADJUSTED SLIGHTLY TO ACCOUNT FOR
SLOWING TRENDS IN TEMPERATURES RISING SLOWER THAN FORECAST SO
FAR THIS MORNING. EXPECT ADDITIONAL RAIN SHOWERS TO MOVE INTO
THE AREA OVERNIGHT, WHICH WILL BRING CHANCES FOR DENSE FOG AGAIN
TO PORTIONS OF NW NC AND SW VA.
PREVIOUS DISCUSSION:
KEY MESSAGE:
1) MILD WEATHER WITH ISOLATED RAIN CHANCES THROUGH TONIGHT.
2) COLD FRONT STALLS ACROSS THE AREA AND LIFTS NORTH AS A WARM
FRONT TONIGHT.
AREAS OF DENSE FOG THIS MORNING AHEAD OF A WEAK SURFACE FRONT
APPROACHING FROM THE WEST. MONDAY NIGHT RAOB INDICATES NEARLY
UNIDIRECTIONAL WEST FLOW EXCEPT FOR THE LOWEST LEVELS WHERE A
WEAK IN-SITU WEDGE REMAINS IN PLACE. THIS WILL EVENTUALLY ERODE
AROUND DAYBREAK AS THE SURFACE COLD FRONT SLOWLY CROSSES
THROUGH THE REGION. ONLY EXPECTING A FEW SHOWERS EARLY THIS
MORNING WITH THE PASSAGE OF THE FRONT, MAINLY ACROSS THE WESTERN
MOUNTAINS.
COLD FRONT WILL STALL ALONG THE NC/VA BORDER THIS EVENING AND
THEN BEGIN TO LIFT NORTH AGAIN AS A WARM FRONT LATE TONIGHT.
LIGHT SHOWERS POSSIBLE AGAIN LATE TONIGHT ASSOCIATED WITH THE
WARM FRONT AS IT MOVES NORTH. RAINFALL AMOUNTS WILL BE LIGHT,
GENERALLY AROUND 0.10" OR LESS.
LIGHT SOUTHWEST FLOW AHEAD OF THE FRONT WILL ALLOW FOR HIGH
TEMPERATURES IN THE PIEDMONT REGION TO WARM INTO THE LOW TO MID
60S. MID 50S IN THE MOUNTAINS.
SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/
AS OF 345 AM EST TUESDAY...
KEY POINTS:
1) MORE WIDESPREAD RAIN EXPECTED FOR MIDWEEK.
2) BITTER COLD RETURNS FOR THE END OF THE WEEK.
THE MEAN TROUGH AXIS WILL STILL BE LOCATED TO THE WEST OF THE
REGION WEDNESDAY AS ANOTHER VIGOROUS DISTURBANCE ROUNDS THE BASE
OF THE TROUGH AND HEADS INTO THE MID-ATLANTIC REGION. SIMILAR TO
THE PATTERN OF THIS PAST WEEKEND, WIDESPREAD RAIN WILL SPREAD
INTO THE REGION FROM THE SOUTHWEST WITHIN AN ACTIVE BAROCLINIC
ZONE STRETCHED FROM THE ARKLATEX REGION INTO THE MID-ATLANTIC.
RAINFALL AMOUNTS ARE EXPECTED TO AVERAGE AROUND 1/2 INCH FOR
MUCH OF THE FORECAST AREA WITH SLIGHTLY HIGHER AMOUNTS POSSIBLE
IN THE WESTERN PART OF THE CWA ACROSS THE MOUNTAINS. THESE
AMOUNTS SHOULD BE MODEST ENOUGH, DESPITE THE SATURATED GROUND
FROM THE RECENT RAINFALL, THAT NO FLOODING PROBLEMS ARE
ANTICIPATED. WITH THE REGION IN THE WARM SECTOR (850 MB
TEMPERATURES ~+8C) AS THE DISTURBANCE MOVES THROUGH THE AREA,
PRECIPITATION IS EXPECTED TO BE IN THE FORM OF ALL LIQUID.
IN THE WAKE OF THIS DISTURBANCE, THE UPPER-LEVEL TROUGH WILL
SHIFT FURTHER EAST OVER THE EASTERN U.S. AS A NORTHERN STREAM
SHORT WAVE DIVES SOUTHEASTWARD INTO THE CENTRAL APPALACHIANS
FRIDAY. STRONG COLD ADVECTION AND INCREASING UPSLOPE NORTHWEST
FLOW WILL BRING SNOW SHOWERS BACK TO THE MOUNTAINS WITH MINOR
SNOW ACCUMULATIONS POSSIBLE FRIDAY INTO EARLY SATURDAY. 850MB
TEMPERATURES WILL PLUMMET BACK TO THE -12C RANGE BY THE WEEKEND
ENDING THE STRETCH OF MID TO LATE WEEK MILDER TEMPERATURES.
/CONFIDENCE LEVELS IN FORECAST PARAMETERS/
- MODERATE TO HIGH CONFIDENCE IN TEMPERATURES,
- MODERATE TO HIGH CONFIDENCE IN PRECIPITATION PROBABILITIES,
- MODERATE TO HIGH CONFIDENCE IN WIND DIRECTION AND SPEED.
LONG TERM /SATURDAY THROUGH MONDAY/
AS OF 400 AM EST TUESDAY...
KEY POINTS:
1) BITTER COLD TEMPERATURES RETURN ONCE AGAIN FOR THE WEEKEND.
2) OUTSIDE OF MOUNTAIN SNOW SHOWERS, MAINLY A DRY FORECAST FOR
THE WEEKEND INTO THE FIRST OF NEXT WEEK.
THE UPPER TROUGH WILL SHIFT FURTHER EAST BY THE WEEKEND PUTTING
THE REGION BACK IN DEEP NORTHWEST FLOW. THIS WILL ALLOW MUCH
COLDER AIR TO PLUNGE BACK INTO THE REGION FOR THE WEEKEND
SENDING TEMPERATURES TO BELOW NORMAL LEVELS ONCE AGAIN. 850MB
TEMPERATURES WILL DROP FROM +5C EARLY FRIDAY TO -10C BY SATURDAY
AND REMAIN IN THE DEEP FREEZE UNTIL MONDAY. MOISTURE WILL BE
LIMITED, BUT SIGNIFICANT DYNAMICS WITH A NORTHWEST FLOW SHORT
WAVE HELPING TO DRIVE THE MAIN TROUGH FURTHER EAST/SOUTHEAST
WILL SUPPORT SOME SNOW SHOWERS ACROSS THE MOUNTAINS IMMEDIATELY
FOLLOWING THE FRONTAL PASSAGE DURING STRONG COLD ADVECTION.
MINOR ACCUMULATIONS UP TO 2 INCHES OR SO WILL BE POSSIBLE ACROSS
WESTERN GREENBRIER COUNTY AND PERHAPS AN INCH OR SO FURTHER
SOUTH INTO THE MOUNTAINS OF SOUTHWEST VA.
LOW TEMPERATURES OVER THE WEEKEND WILL BE MAINLY IN THE TEENS
WEST TO THE 20S EAST WITH HIGH TEMPERATURES REMAINING AT OR
BELOW FREEZING IN THE WESTERN/HIGHER TERRAIN AREAS OF THE CWA TO
THE 40S ACROSS THE PIEDMONT.
/CONFIDENCE LEVELS IN FORECAST PARAMETERS/
- MODERATE TO HIGH CONFIDENCE IN TEMPERATURES,
- MODERATE CONFIDENCE IN PRECIPITATION PROBABILITIES,
- MODERATE TO HIGH CONFIDENCE IN WIND DIRECTION AND SPEED.
AVIATION /18Z 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.
RNK WATCHES/WARNINGS/ADVISORIES
VA...NONE.
NC...NONE.
WV...NONE.
SYNOPSIS...BMG
NEAR TERM...BMG/EB
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...BMG/EB
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