158
FXUS61 KRNK 160958
AFDRNK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
458 AM EST THU JAN 16 2025
SYNOPSIS
LOW PRESSURE CROSSING THE OHIO VALLEY BRING SNOW AND GUSTY WIND
TODAY AND TONIGHT THEN HIGH PRESSURE WILL COVER THE MID ATLANTIC AND
CAROLINAS FRIDAY. A LARGE STORM SYSTEM WITH WIDESPREAD PRECIPITATION
ARRIVES FOR FRIDAY NIGHT THROUGH SATURDAY IN ADVANCE OF AN ARCTIC
AIRMASS FOR NEXT WEEK.
NEAR TERM /THROUGH FRIDAY/
AS OF 430 AM EST THURSDAY...
KEY MESSAGES:
- WINTER STORM WARNING REMAINS IN EFFECT FOR WESTERN GREENBRIER
TODAY AND TONIGHT
- WINTER WEATHER ADVISORY ISSUED FOR MERCER AND SUMMER COUNTIES
SHORT WAVE CROSSING THROUGH THE LONG WAVE EASTERN UNITED STATES
TROUGH WILL MOVE THROUGH THE MID ATLANTIC AREA TODAY AND TONIGHT.
THE BEST SYNOPTIC SCALE LIFT WITH THE UPPER JET AND POSITIVE
VORTICITY ADVECTION, FOLLOWED BY UPSLOPE LIFT WILL BE IN THE 10AM-
10PM TIME FRAME. ENOUGH LIQUID EQUIVALENT PRECIPITATION, AROUND 0.5
INCHES AND LARGE ENOUGH SNOW RATIOS, ROUGHLY 15:1 TO GET SNOW
ACCUMULATIONS IN SOUTHEAST WEST VIRGINIA OF 2 TO 8 INCHES. SOME
LOCALLY HIGHER AMOUNTS ARE POSSIBLE IN WESTERN GREENBRIER COUNTY.
ALSO MODELS ARE SUGGESTING SOME RELATIVE INSTABILITY THIS AFTERNOON
THAT MAY BE ENOUGH FOR SNOW SQUALLS OR AT LEAST NARROW BANDS OF
HEAVIER SNOWFALL RATES. COLDER AIR ALOFT DOES ARRIVE IN THE AREA
AROUND THAT TIME. BIGGEST QUESTION IS THE AMOUNT OF MOISTURE. THE
AIR MASS IS STARTING THE DAY WELL BELOW 0.25 INCHES OF PRECIPITABLE
WATER AND SOME OF THE EARLY SNOWFALL MAY GO INTO SATURATING THE AIR
MASS INSTEAD OF ACCUMULATING. BUT, EVENTUALLY THE PRECIPITABLE WATER
VALUES ARE BACK UP AROUND 0.25 INCHES. LATEST HRRR HAS THE SNOW
REACHING MOST OF SOUTHEAST WEST VIRGINIA BETWEEN 7AM AND 10AM.
THIS FEATURE GOES BY WITH THE 500MB TROUGH AXIS TO THE EAST BY
FRIDAY MORNING. WINDS TURN TO THE WEST AND NORTHWEST TONIGHT. THE
LOW LEVEL JET INCREASES THIS EVENING WITH THE STRONGEST 850MB WIND
FROM 00Z/7PM TO 06Z/1AM WITH GOOD PRESSURE RISES, 5-8MB IN 6 HOURS
AT THE SAME TIME. WILL ASSESS AGAIN TODAY TO DETERMINE IF A WIND
ADVISORY IS NEEDED ALONG THE SOUTHERN BLUE RIDGE. WIND SPEEDS DROP
OFF QUICKLY BY FRIDAY MORNING. BY THEN SURFACE HIGH PRESSURE
DIRECTLY OVER THE CENTRAL AND SOUTHERN APPALACHIANS.
UPPER RIDGING ON FRIDAY AND MORE SUNSHINE WILL RESULT IN
TEMPERATURES AROUND NORMAL. STAYED CLOSE TO A NBM/LAV GUIDANCE BLEND
FOR HIGHS AND LOWS THROUGH THIS PERIOD.
SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/
AS OF 400 AM EST THURSDAY...
KEY MESSAGES:
1) WINTRY MIX TURNS TO RAIN SATURDAY
2) UPSLOPE SNOW SUNDAY
AN INITIAL SHORTWAVE WILL MOVE THROUGH THE AREA ON SATURDAY MORNING,
AND BRING A FRONT THROUGH BY SATURDAY NIGHT. THE TEMPERATURE IN THE
MORNING WILL BE KEY TO THE PRECIPITATION TYPE, AS MOST OF THE
MOUNTAIN REGIONS WILL HAVE SURFACE AND MID-LEVEL TEMPERATURES NEAR
32F. PRECIPITATION WILL BEGIN AS A WINTRY MIX, LIKELY SNOW/SLEET,
BEFORE BECOMING MOSTLY SLEET, AND EVENTUALLY RAIN AROUND MID-
MORNING. IN SOME OF THE PEAK ELEVATIONS AROUND THE HIGH COUNTRY OF
NC AND IN SOUTHEASTERN WV, SOME BRIEF PERIODS OF FREEZING RAIN ARE
ALSO POSSIBLE. WITH HOW BRIEF THAT WINDOW IS, HOWEVER, ICING IMPACTS
WILL BE MINIMAL AND LIKELY RESTRICTED TO RAISED SURFACES, BRANCHES,
AND OVERPASSES. IT WILL BE EXTREMELY DIFFICULT FOR ICE TO FORM ON
TREATED ROADS, AND WITH MORE RAIN COMING THROUGHOUT THE DAY
SATURDAY, AND EXPECTED HIGHS IN THE UPPER 30S TO 40S, ICING WILL NOT
BE A MAJOR ISSUE.
WHEN THE FRONT MOVES THROUGH LATER SATURDAY NIGHT INTO SUNDAY, COLD
AIR WILL FILL IN QUICKLY, BUT IT WILL ALSO BE A MUCH DRIER AIRMASS.
PRECIPITATION WILL TURN BACK TO SNOW, BUT COVERAGE WILL MOSTLY BE
HELD TO WESTERN UPSLOPE ZONES. ACCUMULATION WILL BE LIGHT, RANGING
FROM A DUSTING TO AN INCH.
LONG TERM /MONDAY THROUGH WEDNESDAY/
AS OF 430 AM EST THURSDAY...
KEY MESSAGE:
1) BITTER COLD TEMPERATURES NEXT WEEK
THE APPROACH OF A STRONG AREA OF HIGH PRESSURE AND A FRIGID ARCTIC
AIR MASS WILL TAKE OVER THE WEATHER PATTERN FOR MOST OF THE EASTERN
CONUS THE FIRST HALF OF NEXT WEEK. AN AMPLIFYING PACIFIC RIDGE WILL
CREATE A DIGGING TROUGH ON THE ATLANTIC HALF OF THE COUNTRY, PUSHING
FRIGID AIR OUT OF THE NORTHERN STREAM. THIS ANOMALOUSLY COLD AIR
MASS WILL FEATURE 850MB TEMPS IN THE 20-25C BELOW ZERO RANGE, AND
SURFACE TEMPERATURES BOTTOMING OUT IN -5F FOR PARTS OF THE MOUNTAINS
OF WV, AND +10-15F IN THE PIEDMONT. SOME OF OUR CLIMATE SITES MAY BE
CLOSE TO OR TIE SOME COLD RECORDS, AND IT WILL CERTAINLY BE SOME OF
THE COLDEST AIR WE'VE SEEN THIS SEASON.
A LATE WEEK WAVE MOVING FROM THE SOUTHERN PLAINS TOWARD THE OH
VALLEY IS BEGINNING TO SHOW IN SOME LONG TERM MODEL GUIDANCE. THIS
COULD BE ANOTHER SYSTEM TO WATCH FOR WINTER WEATHER IN OUR
FORECAST AREA.
AVIATION /10Z THURSDAY THROUGH MONDAY/
AS OF 450 AM EST THURSDAY...
SHORT WAVE CROSSING THROUGH THE LONG WAVE EASTERN UNITED STATES
TROUGH WILL MOVE THROUGH THE MID ATLANTIC AREA TODAY AND
TONIGHT. THE BEST SYNOPTIC SCALE LIFT WITH THE UPPER JET AND
POSITIVE VORTICITY ADVECTION, FOLLOWED BY UPSLOPE LIFT WILL BE
IN THE 10AM- 10PM TIME FRAME. MID LEVEL CLOUD HAD ALREADY SPREAD
INTO VIRGINIA AND WESTERN NORTH CAROLINA. LATEST HRRR HAS THE
SNOW REACHING MOST OF SOUTHEAST WEST VIRGINIA BETWEEN 7AM AND
10AM. HAVE LIGHT SNOW IN THE KLWB AND KBLF TAFS AT 15Z/10AM.
CEILINGS WILL DROP TO MVFR IN THE MOUNTAINS AROUND 00Z/7PM.
GFS AND OTHER MODELS ARE SUGGESTING SOME RELATIVE INSTABILITY
THIS AFTERNOON THAT MAY BE ENOUGH FOR SNOW SQUALLS OR AT LEAST
NARROW BANDS OF HEAVIER SNOWFALL RATES AND IFR TO MVFR
VISIBILITY. COLDER AIR ALOFT DOES ARRIVE IN THE AREA AROUND
THAT TIME. THIS MAY IMPACT KLWB AND KBLF BUT CHALLENGING TO PIN
DOWN A TIME THIS FAR IN ADVANCE.
THIS FEATURE GOES BY WITH THE 500MB TROUGH AXIS TO THE EAST BY
FRIDAY MORNING. WINDS TURN TO THE WEST AND NORTHWEST TONIGHT. THE
LOW LEVEL JET INCREASES THIS EVENING WITH THE STRONGEST 850MB WIND
FROM 00Z/7PM TO 06Z/1AM WITH GOOD PRESSURE RISES, 5-8MB IN 6 HOURS
AT THE SAME TIME. WIND WILL GUST 25 TO 40 KNOTS IN THIS TIME
RANGE, ESPECIALLY AT HIGHER ELEVATIONS ALONG THE BLUE RIDGE
SOUTH OF KROA.
WIND SPEEDS DROP OFF QUICKLY BY FRIDAY MORNING. BY THEN SURFACE
HIGH PRESSURE DIRECTLY OVER THE CENTRAL AND SOUTHERN APPALACHIANS.
AVIATION OUTLOOK...
FRIDAY MORNING MVFR CEILINGS WILL PERSIST IN THE MOUNTAINS UNTIL
THE UPSLOPE FLOW WEAKENS. OTHERWISE, CONDITIONS WILL BE WARMER
AND VFR.
A LARGER LOW PRESSURE SYSTEM IS EXPECTED TO BRING WIDESPREAD
PRECIPITATION AND POOR FLYING CONDITIONS FRIDAY NIGHT AND
SATURDAY ACROSS THE REGION, AND THROUGH SUNDAY WITH UPSLOPE
SNOW SHOWERS IN THE MOUNTAINS.
MONDAY WILL BE UNSEASONABLY COLD, DRY AND VFR.
RNK WATCHES/WARNINGS/ADVISORIES
VA...NONE.
NC...NONE.
WV...WINTER WEATHER ADVISORY UNTIL 7 AM EST FRIDAY FOR WVZ042-043.
WINTER STORM WARNING UNTIL 7 AM EST FRIDAY FOR WVZ508.
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...VFJ
LONG TERM...VFJ
AVIATION...AMS/JCB
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