057
FXUS61 KRNK 180020
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
720 PM EST FRI JAN 17 2025
SYNOPSIS
A LOW PRESSURE SYSTEM WILL BRING A LIGHT WINTRY MIX FOR LATE
TONIGHT INTO SATURDAY MORNING BEFORE CHANGING TO RAIN BY
SATURDAY AFTERNOON. THE PRECIPITATION SHOULD SWITCH BACK TO SNOW
BY SATURDAY NIGHT AND SUNDAY AS AN ARCTIC AIR MASS ARRIVES TO
BRING THE COLDEST TEMPERATURES SO FAR THIS WINTER FOR EARLY NEXT
WEEK. ANOTHER LOW PRESSURE SYSTEM MAY DEVELOP ALONG THE GULF
COAST DURING THE MIDDLE OF NEXT WEEK.
NEAR TERM /THROUGH SATURDAY/
AS OF 720 PM EST FRIDAY...
KEY MESSAGES:
1) CONFIDENCE IS HIGH FOR CLOUDS INCREASING TONIGHT WITH A LIGHT
WINTRY MIX ENTERING SATURDAY MORNING.
2) ANY MIXED PRECIPITATION SHOULD TRANSITION TO RAIN BY MIDDAY
SATURDAY AND TAPER OFF BY SATURDAY EVENING.
CLOUDS SHOULD GRADUALLY INCREASE FROM THE WEST OVERNIGHT, WHILE
TEMPERATURES DROP TO NEAR OR JUST BELOW FREEZING. A LOW
PRESSURE SYSTEM WILL APPROACH THE APPALACHIAN MOUNTAINS AFTER
MIDNIGHT AS A SOUTHERN STREAM SHORTWAVE TROUGH PHASES WITH THE
UPPER LONGWAVE TROUGH FROM THE NORTH TO ADVECT MOISTURE. THERMAL
PROFILES ALLOW A LIGHT WINTRY MIX STARTING EARLY SATURDAY
MORNING. LIGHT ICING ACCUMULATIONS ARE POSSIBLE FROM FREEZING
RAIN IN THE MOUNTAINS, WHILE LIGHT SNOW AND SLEET AMOUNTS ARE
ANTICIPATED ACROSS THE HIGHER ELEVATIONS OF NORTHWEST NORTH
CAROLINA, THE ALLEGHANY HIGHLANDS OF VIRGINIA, AND GREENBRIER
COUNTY OF WEST VIRGINIA.
WARM AIR ADVECTION NEAR THE SURFACE FROM A SOUTHERLY FLOW SHOULD
PUSH TEMPERATURES ABOVE FREEZING DURING SATURDAY MORNING.
WHATEVER FROZEN ACCUMULATIONS OCCUR SHOULD MELT BY MIDDAY AS ALL
PRECIPITATION TRANSITIONS TO RAIN. THE RAIN SHOULD TAPER ACROSS
THE PIEDMONT BY SATURDAY AFTERNOON, WHILE DRIZZLE AND LOW CLOUDS
COULD LINGER ALONG AND WEST OF THE BLUE RIDGE. HIGH TEMPERATURES
BY SATURDAY AFTERNOON SHOULD REACH THE 40S FOR MOST LOCATIONS,
WHILE LOWER 50S MAY BE POSSIBLE TOWARDS DANVILLE. THE HIGHEST
ELEVATIONS, HOWEVER, MAY STRUGGLE TO REACH THE UPPER 30S.
SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/
AS OF 245 PM EST FRIDAY...
KEY MESSAGES:
1) ARCTIC COLD FRONT ARRIVES SUNDAY.
2) BITTER COLD TEMPERATURES EXPECTED MONDAY AND BEYOND.
3) INCREASED THREAT FOR ACCUMULATING SNOW SUNDAY.
DEEP UPPER TROUGH CARVES OUT ACROSS THE EASTERN U.S. IN THE WAKE
OF A MID-ATLANTIC DEVELOPING COASTAL SYSTEM THAT IS DEEPER AND
MORE PROBLEMATIC IN TERMS OF SNOWFALL SUNDAY THAN EXPECTED IN
PRIOR DAY'S FORECASTS. THIS DEEPENING WILL INITIATE THE ARCTIC
SURGE BRINGING IN THE COLDEST TEMPERATURES SINCE DECEMBER 2022.
HOWEVER, UNLIKE THE LATE DECEMBER 2022 COLD OUTBREAK, THIS WILL
LAST MUCH LONGER, LIKELY MONDAY THROUGH THURSDAY AT A MINIMUM.
TEMPERATURES SUNDAY WILL BE ON A NON-DIURNAL TREND FROM THE 30S
IN THE MORNING TO THE TEENS BY SUNSET WEST AND 20S EAST. BY
MONDAY MORNING, TEMPERATURES WILL ALREADY BE DOWN IN THE SINGLE
DIGITS TO EVEN NEAR 0 IN THE HIGHER ELEVATIONS OF THE WESTERN
MOUNTAINS WITH TEENS IN THE PIEDMONT. THUS, THE NEED FOR AN
EXTREME COLD WATCH.
WITH RESPECT TO SNOW, MODELS HAVE TRENDED STRONGER WITH A
COASTAL LOW DEVELOPING OFF THE VA COAST SUNDAY IN RESPONSE TO A
STRONG SOUTHERN STREAM SHORTWAVE. A NOTABLE INCREASE FROM
YESTERDAY'S FORECAST. SNOW AMOUNTS OF 1-2 INCHES NOW APPEAR
POSSIBLE ACROSS THE NORTHERN PARTS OF THE RNK PIEDMONT COUNTIES,
SUCH AS THE LYNCHBURG AND LEXINGTON AREAS. THE HEAVIER SNOW
AMOUNTS (I.E., ADVISORY OR WARNING CRITERIA) WILL REMAIN NORTH
OF I-64 AS THE COASTAL LOW RAPIDLY INTENSIFIES GOING UP THE
NORTHERN MID-ATLANTIC COAST. MEANWHILE, THE UPSLOPE SNOW
MACHINE WILL BEGIN WITH STRONG COLD ADVECTION BY SUNDAY
AFTERNOON/EVENING AND CONTINUE INTO MONDAY. HENCE, THE WINTER
STORM WATCH FOR WESTERN GREENBRIER COUNTY.
/CONFIDENCE LEVELS FOR FORECAST PARAMETERS/
- MODERATE TO HIGH CONFIDENCE IN TEMPERATURES,
- MODERATE CONFIDENCE IN PRECIPITATION PROBABILITIES,
- MODERATE CONFIDENCE IN WIND SPEED, HIGH CONFIDENCE IN WIND
DIRECTION.
LONG TERM /TUESDAY THROUGH FRIDAY/
AS OF 330 PM EST FRIDAY...
KEY MESSAGES:
1) EXTENDED PERIOD OF BITTER COLD AND WELL BELOW FREEZING
TEMPERATURES. EXTREME COLD WATCH ISSUED.
2) ADDITIONAL POTENTIAL SNOW EVENTS POSSIBLE THROUGH THE
PERIOD.
BITTER ARCTIC COLD EXPECTED THROUGH THE PERIOD. COLDEST
TEMPERATURES SINCE DECEMBER 2022, BUT MUCH LONGER LASTING THAN
THAT COLD SPELL. TEMPERATURES WILL PLUNGE INTO THE SINGLE DIGITS
AND TEENS TO EVEN SINGLE DIGITS BELOW ZERO AS SOON AS MONDAY
MORNING AND STRUGGLE TO EVEN REACH 20 DEGREES THROUGH WEDNESDAY.
ACTUAL LOW TEMPERATURES NEAR -10 POSSIBLE IN THE USUAL ICEBOX
LOCATIONS LIKE BURKES GARDEN AND LEWISBURG MIDWEEK. HENCE THE
EXTREME COLD WATCH WHICH HAS BEEN ISSUED FOR AREAS ALONG/WEST OF
THE BLUE RIDGE. THE COLDEST COMBINATION OF TEMPERATURES AND
WIND WILL OCCUR WEDNESDAY MORNING WHEN LARGE AREAS OF THE
WESTERN PART OF THE CWA MEET EXTREME COLD WARNING CRITERIA.
TEMPERATURES WILL VERY SLOWLY MODERATE THURSDAY THROUGH FRIDAY,
BUT LIKELY REMAIN BELOW FREEZING FOR AREAS ALONG/WEST OF THE
BLUE RIDGE UNTIL FRIDAY.
WITH RESPECT TO PRECIPITATION, THE VERY COLD/DRY AIR APPEARS TO
WIN OUT FOR THE MOST PART. HOWEVER, VIGOROUS SOUTHERN STREAM
SHORT WAVES ARE NOTED TRACKING FROM SOUTH TEXAS TO THE MID-
ATLANTIC REGION. THE TUE-WED SYSTEM IS TRACKING A BIT FURTHER
NORTH THAN EARLIER EXPECTED POTENTIALLY BRINGING LIGHT SNOW TO
MAINLY THE PIEDMONT. UPSLOPE FLOW WILL ADD ADDITIONAL MINOR SNOW
AMOUNTS TO THE WESTERN MOUNTAINS MAINLY TUESDAY. ANOTHER
SOUTHERN STREAM SYSTEM WILL NEED TO BE WATCHED BY FRIDAY.
/CONFIDENCE LEVELS IN FORECAST PARAMETERS/
- MODERATE TO HIGH CONFIDENCE IN TEMPERATURES,
- LOW TO MODERATE CONFIDENCE IN PRECIPITATION PROBABILITIES,
- MODERATE TO HIGH CONFIDENCE IN WIND DIRECTION AND SPEED.
AVIATION /00Z SATURDAY THROUGH WEDNESDAY/
AS OF 720 PM EST FRIDAY...
CONFIDENCE IS HIGH FOR VFR CONDITIONS EARLY TONIGHT, BUT CIRRUS
WILL INCREASE FROM THE WEST OVERNIGHT. CEILINGS SHOULD LOWER AS
THE ATMOSPHERE MOISTENS FROM AN APPROACHING LOW PRESSURE
SYSTEM. BY EARLY SATURDAY MORNING, A LIGHT WINTRY MIX
ACCOMPANIED BY MVFR TO POSSIBLY IFR CEILINGS WILL BEGIN IN THE
MOUNTAINS. THE POTENTIAL FOR A MIX OF SNOW AND SLEET IS HIGHEST
AT LWB, WHILE A MIX OF RAIN AND SLEET IS POSSIBLE FOR BLF AND
BCB. EVEN LYH COULD BRIEFLY SEE A MIX OF RAIN AND SLEET, BUT
ROA APPEARS TO STAY TOO WARM AND SHOULD ONLY EXPERIENCE LIGHT
RAIN. SOME MODEL GUIDANCE ALSO HINTS AT ISOLATED POCKETS OF LOW-
LEVEL WIND SHEAR ALONG THE BLUE RIDGE OVERNIGHT INTO SATURDAY
MORNING, BUT IT IS TOO PATCHY TO SPECIFY AT ANY TERMINAL.
ALL SITES SHOULD TRANSITION TO RAIN AS THE MORNING PROGRESSES
DUE TO A LIGHT SOUTH WIND PUSHING SURFACE TEMPERATURES ABOVE
FREEZING, SO WHATEVER FROZEN PRECIPITATION AMOUNTS OCCUR WILL
MELT BEFORE MIDDAY. LIGHT RAIN WITH LOW CEILINGS AND SOME
RESTRICTIONS TO VISIBILITY IS ANTICIPATED TO LINGER THROUGH THE
MORNING. THE RAIN COVERAGE SHOULD DECREASE FIRST AT LYH AND DAN
BY THE AFTERNOON AND CONTINUE WESTWARD TOWARDS THE BLUE RIDGE.
HOWEVER, SOME LIGHT DRIZZLE OR FOG MAY PERSIST FOR BCB, BLF, AND
LWB THROUGH SATURDAY EVENING. THE WIND SHOULD SHIFT MORE
TOWARDS THE SOUTHWEST AS THE DAY ENDS.
EXTENDED AVIATION OUTLOOK...
LOW CEILINGS, DRIZZLE, AND FOG MAY INITIALLY OCCUR ON SATURDAY
NIGHT. THE WIND WILL SWING TOWARDS THE NORTHWEST IN THE WAKE OF
A LOW PRESSURE SYSTEM, SO THE RAIN SHOULD CHANGE TO SNOW IN THE
MOUNTAINS BY EARLY SUNDAY MORNING. RAIN MAY HOLD TO THE EAST
AND FADE ON SUNDAY AS DRIER AIR ARRIVES. WINDS WILL BECOME
GUSTY FROM THE NORTHWEST BY SUNDAY EVENING, WHILE MOUNTAIN SNOW
SHOWERS CONTINUE INTO SUNDAY NIGHT. CONDITIONS SHOULD IMPROVE
TO VFR BY MONDAY AS THE COLDEST AIR SO FAR THIS WINTER ARRIVES.
A LOW PRESSURE SYSTEM WILL TRACK ALONG THE GULF COAST DURING
TUESDAY AND WEDNESDAY, BUT CONFIDENCE IS TOO LOW TO INDICATE ANY
IMPACTS AS MOST OF THE MOISTURE MAY STAY TOO FAR TO THE SOUTH.
RNK WATCHES/WARNINGS/ADVISORIES
VA...EXTREME COLD WATCH FROM LATE SUNDAY NIGHT THROUGH WEDNESDAY
MORNING FOR VAZ007-009>020.
NC...EXTREME COLD WATCH FROM LATE SUNDAY NIGHT THROUGH WEDNESDAY
MORNING FOR NCZ001-002-018.
WV...EXTREME COLD WATCH FROM LATE SUNDAY NIGHT THROUGH WEDNESDAY
MORNING FOR WVZ042>044-507-508.
WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR WVZ508.
SYNOPSIS...AB/PW
NEAR TERM...AB/PW
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...PW
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