409
FXUS61 KRNK 181019
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
519 AM EST WED DEC 18 2024
SYNOPSIS
A FAIRLY UNSETTLED WEATHER PATTERN WILL LEAD TO WARM
TEMPERATURES AGAIN TODAY, 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 WITH A MUCH COLDER AIRMASS
ARRIVING.
NEAR TERM /THROUGH TONIGHT/
AS OF 215 AM EST WEDNESDAY...
KEY MESSAGES:
1) MILD WEATHER TODAY AHEAD OF A COLD FRONT.
2) RAIN ENTERS THE AREA TONIGHT, WITH THE HIGHEST CHANCES FOR
RAIN ACROSS THE MOUNTAINS.
STALLED FRONT CURRENTLY ACROSS THE NC/VA BORDER WILL DRIFT NORTH
THROUGHOUT TODAY AS A WARM FRONT. MAY HAVE SOME ISOLATED SHOWERY
ACTIVITY AROUND SUNRISE, BUT HIGHEST COVERAGE OF RAIN LOOKS TO
REMAIN TO THE WEST FOR A GOOD PORTION OF DAYLIGHT HOURS TODAY.
COLD FRONT WILL PUSH CLOSER THIS EVENING WITH RAIN OVERSPREADING
WEST VIRGINIA AND FAR SOUTHWEST VIRGINIA BY SUNSET. COULD HAVE
SOME EMBEDDED HEAVIER DOWNPOURS ASSOCIATED WITH THIS LINE.
ALTHOUGH INSTABILITY IS LOW, IT IS NOT ZERO, THUS COULD HAVE A
VERY ISOLATED CHANCE OF A RUMBLE OR TWO MAINLY ACROSS WEST
VIRGINIA AS THE LINE INITIALLY ENTERS THE CWA. NOT VERY
CONFIDENT THAT WIDESPREAD RAINFALL MAKES IT EAST OF THE
MOUNTAINS JUDGING BY NEWEST HI-RES GUIDANCE. HIT OR MISS SHOWERS
SEEMING MORE LIKELY ACROSS THE FOOTHILLS AND PIEDMONT.
WARM FRONT LOOKS TO MAKE IT TO AROUND THE I-64 CORRIDOR BY THE
AFTERNOON, SO SHOULD SEE HIGHS INTO THE LOW/MID 60S FOR
LOCATIONS SOUTH OF I-64. LOCATIONS ALONG AND NORTH OF I-64
REMAIN IN THE 50S.
SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/
AS OF 430 AM EST WEDNESDAY...
KEY MESSAGES:
1). TRANSITION BACK TO MUCH COLDER, BELOW NORMAL TEMPERATURES.
2). LIMITED UPSLOPE SNOW SHOWERS POSSIBLE BEHIND A COLD FRONT,
BUT BETTER CHANCE FOR SNOW SHOWERS FRIDAY NIGHT INTO SATURDAY
WITH A SECONDARY COLD FRONT.
3). EXTENDED PERIOD OF BELOW NORMAL/SUB FREEZING TEMPERATURES
EXPECTED ALONG AND WEST OF THE BLUE RIDGE.
RAIN WILL WIND DOWN AND END EARLY THURSDAY AS THE SUPPORTING
SHORT WAVE RAPIDLY EXITS THE AREA TO THE EAST AROUND DAYBREAK.
MEANWHILE, THE NORTHERN STREAM WILL INTENSIFY AND DIG SOUTHWARD
AS A STRONG SHORT WAVE TRACKS SOUTHEAST OUT OF CENTRAL CANADA
INTO THE MIDWEST. COLD ADVECTION WILL BEGIN IN THE WAKE OF THE
INITIAL SHORT WAVE/FRONTAL SYSTEM, BUT WILL INCREASE AS THE
STRONGER, SECONDARY SYSTEM DIVES SOUTHEAST INTO THE REGION
FRIDAY-SATURDAY. 850MB TEMPERATURES WILL PLUNGE FROM +8C
TODAY/WEDNESDAY TO AROUND -8C BY FRIDAY EVENING, THEN CONTINUE
TO DROP FURTHER WITH THE SECONDARY SHORT WAVE TO AROUND -11C BY
SATURDAY EVENING. WHILE LIMITED SNOW SHOWERS WILL BE POSSIBLE
EARLY THURSDAY BEHIND THE FIRST FRONT, ANOTHER AND MORE
SIGNIFICANT ROUND OF SNOW SHOWERS IS EXPECTED TO ACCOMPANY THE
SECONDARY MORE DYNAMIC TROUGH/COLD FRONT FRIDAY INTO SATURDAY.
WITH GULF MOISTURE ESSENTIALLY CUT OFF FROM THE AREA, SNOW FOR
THE MOST PART SHOULD REMAIN LIGHT WITH LITTLE EXPECTED
ALONG/EAST OF THE BLUE RIDGE.
ONCE 850MB TEMPERATURES DROP BELOW FREEZING THURSDAY EVENING,
THEY WILL REMAIN BELOW 0C THROUGH THE WEEKEND, RISING ABOVE 0C
SOMETIME MONDAY MORNING. THIS WILL EQUATE TO A VERY COLD WEEKEND
WITH TEMPERATURES AROUND 10F DEGREES BELOW NORMAL. HIGH
TEMPERATURES WILL RANGE FROM THE 20S/30S WEST TO THE 40S EAST
WITH OVERNIGHT LOW TEMPERATURES IN THE TEENS AND 20S. FOR THE
HIGHER TERRAIN WEST OF THE BLUE RIDGE, MUCH OF THE PERIOD FRIDAY
EVENING THROUGH MONDAY WILL REMAIN AT OR BELOW FREEZING EVEN
DURING THE DAYTIME.
/CONFIDENCE LEVELS IN FORECAST PARAMETERS/
- MODERATE TO HIGH CONFIDENCE IN TEMPERATURES,
- MODERATE CONFIDENCE IN PRECIPITATION0 PROBABILITIES,
- MODERATE CONFIDENCE IN WIND DIRECTION AND SPEED.
LONG TERM /SUNDAY THROUGH TUESDAY/
AS OF 500 AM EST WEDNESDAY...
KEY MESSAGES:
1). COLD, BELOW NORMAL TEMPERATURES REMAIN IN PLACE THROUGH THE
PERIOD.
2). MAINLY DRY WITH THE NEXT PRECIPITATION EVENT NOT REACHING
THE REGION UNTIL THE LATER HALF OF NEXT WEEK.
AN ACTIVE/PROGRESSIVE PATTERN WILL REMAIN IN PLACE AS BOTH THE
NORTHERN AND SOUTHERN STREAM REMAIN FAIRLY ACTIVE. FOR OUR
REGION, THE NORTHERN STREAM WILL DOMINATE WITH PREVAILING
NORTHWEST FLOW ON THE BACK SIDE OF A DEEPENING MID-ATLANTIC
UPPER TROUGH. THIS PATTERN WILL KEEP A FETCH OF COLD/DRY AIR IN
PLACE FROM SOUTH CENTRAL CANADA INTO THE MID- ATLANTIC REGION
FOR SEVERAL DAYS. WHILE COLD, ALSO DRY, WITH GULF MOISTURE CUT
OFF. LIGHT PRECIPITATION AMOUNTS WEST OF THE BLUE RIDGE WITH
LITTLE MEASURABLE PRECIPITATION EAST OF THE BLUE RIDGE.
THE COLD AIR MASS WILL BE FIRMLY ENTRENCHED ACROSS THE REGION
SUNDAY AND LINGER THROUGH THE FIRST HALF OF THE NEXT WEEK BEFORE
FINALLY LIFTING OUT OF THE AREA MIDWEEK, LOW TEMPERATURES WILL
TREND BELOW NORMAL DURING THE DAYTIME AND NEAR NORMAL THROUGH
THE WEEKEND WITH MAXIMUM TEMPERATURES IN THE 30S AND 40S AND
POINTS WEST TO THE 40S PIEDMONT. LOW TEMPERATURES WILL AVERAGE
IN THE 30S AND 40S.
KEY
MESSAGES:
- COLDER TEMPERATURES RETURN TO THE FORECAST AREA THIS 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 /10Z WEDNESDAY THROUGH SUNDAY/
AS OF 215 AM EST TUESDAY...
CEILINGS WILL VARY FROM VFR WITH LITTLE CLOUDS TO IFR AND LOW
CLOUDS. AREAS OF FOG ALSO REDUCING VSBY TO 1/2SM OR LESS ACROSS
MUCH OF THE NEW RIVER VALLEY AND ALSO ACROSS THE FOOTHILLS AND
PIEDMONT OF NORTH CAROLINA AND SOUTHERN VIRGINIA. WILL LIKELY
CONTINUE TO SEE AREAS OF DENSE FOG IN THESE LOCATIONS THROUGH
DAYBREAK.
LATER TODAY APPEARS TO BE IN THE MVFR CATEGORY FOR MOST
TERMINALS WITH RAIN MAKING IT TO LWB/BLF/BCB BY MID/LATE
AFTERNOON AND THEN BECOMING LESS WIDESPREAD TONIGHT FOR ROA AND
EAST.
WINDS WILL BE LIGHT/CALM TONIGHT, THEN SHIFT TO THE SOUTHWEST
THIS AFTERNOON WITH GUSTS 15-20KTS.
EXTENDED AVIATION OUTLOOK...
ADDITIONAL SHOWERS AND SUB-VFR CONDITIONS ARE POSSIBLE 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 FOR SUNDAY.
RNK WATCHES/WARNINGS/ADVISORIES
VA...NONE.
NC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR NCZ003>006-
019-020.
WV...NONE.
SYNOPSIS...BMG
NEAR TERM...BMG/WP
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...BMG
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