538
FXUS62 KGSP 131759
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1259 PM EST SAT DEC 13 2025
SYNOPSIS
AN ARCTIC COLD FRONT WILL CROSS THE REGION EARLY SUNDAY, USHERING
IN BITTERLY COLD TEMPERATURES TO START THE WEEK. THE ARCTIC
HIGH PRESSURE SYSTEM WILL QUICKLY SHIFT TO THE EAST AND ALLOW
TEMPERATURES TO QUICKLY REBOUND BY MIDWEEK. ANOTHER COLD FRONT
MAY BRING A RETURN OF RAIN CHANCES LATE IN THE WEEK.
NEAR TERM /THROUGH SUNDAY/
AS OF 1230 PM EST SATURDAY: A BROAD LONG WAVE TROUGH OVER THE
REGION WILL SHARPEN TONIGHT INTO SUNDAY, AS A STRONG SPEED MAX DIGS
FROM THE NORTHERN GREAT PLAINS THIS AFTERNOON TO THE SOUTHERN AND
CENTRAL APPALACHIANS BY LATE SUNDAY MORNING. ASSOCIATED ARCTIC COLD
FRONT WILL SWEEP QUICKLY ACROSS OUR FORECAST AREA FROM ~SHORTLY
AFTER MIDNIGHT THROUGH AROUND SUNRISE. THE STRONGEST AND DEEPEST
FORCING WILL PASS NORTH OF THE CWA, BUT THERE MAY BE ENOUGH WEAK
MOISTURE RETURN AHEAD OF THE FRONT TO SQUEEZE OUT A SHOWER OR
TWO...BUT PRECIP CHANCES WILL BE HIGHEST TO OUR NORTH (STRONGER
FORCING) AND SOUTH (BETTER MOISTURE RETURN), WITH MAINLY TOKEN
20-30 POPS ACROSS OUR AREA. IN THE WAKE OF THE FRONT, STRONG NW
COLD ADVECTION FLOW WILL BECOME ESTABLISHED, WITH MOIST UPSLOPE
FLOW SUPPORTING SCATTERED/NUMEROUS SNOW SHOWER DEVELOPMENT IN
THE VICINITY OF THE TN/NC BORDER FROM AROUND THE PRE-DAWN HOURS
THROUGH MUCH OF THE MORNING. HOWEVER, THERMODYNAMIC INGREDIENTS
SUPPORTING ACCUMULATING SNOW SHOWERS WILL BE IN PLACE ONLY VERY
BRIEFLY, WITH THE POTENTIAL FOR A COUPLE OF INCHES BEING MAINLY
CONFINED TO THE HIGH PEAKS ALONG THE STATE LINE.
OTHERWISE, TEMPS WILL PLUMMET BEHIND THE FRONT, WITH SUNDAY'S HIGH
TEMPS LIKELY OCCURRING AROUND MIDNIGHT TONIGHT. AFTER THE INITIAL
SURGE OF COLD ADVECTION, TEMPS ARE FORECAST TO SLOWLY FALL ACROSS
THE MOUNTAINS, WHILE REMAINING STEADY OR SLOWLY RISING ELSEWHERE
(DUE TO THE OFFSETTING EFFECTS OF WARMING DOWNSLOPE FLOW.) WINDS
WILL BE VERY GUSTY THROUGH THE DAY, WITH GUSTS OF 30-40 MPH
EXPECTED ACROSS THE HIGH ELEVATIONS AND IN THE DOWNSLOPE ZONE
ALONG THE BLUE RIDGE ESCARPMENT. THESE VERY GUSTY WINDS WILL
PERSIST THROUGH SUNSET, WHEN TEMPS ARE LIKELY TO BEGIN FALLING
MORE SHARPLY. AS A RESULT, WIND CHILL VALUES ABOVE 3500 FEET OR
SO ACROSS THE NORTHERN AND CENTRAL NC MOUNTAINS ARE FORECAST TO
MEET OR EXCEED COLD WX ADVISORY CRITERIA...AND ONE WILL BE ISSUED
FOR THESE AREAS FROM 5 PM SUNDAY THROUGH SUNDAY NIGHT.
SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/
AS OF 1200 PM EST SATURDAY:
KEY MESSAGE: ARCTIC FRONT BRINGS GUSTY WINDS WITH BITTERLY COLD
TEMPERATURES SUNDAY NIGHT THROUGH MONDAY.
STRONG 850 MB CAA AND SFC PRESSURE RISES WILL KEEP GUSTY WINDS INTO
THE EVENING SUNDAY, AS TEMPS CONTINUE TO PLUMMET BEHIND THE PASSAGE
OF AN ARCTIC FRONT. WINDS WILL BEGIN TO WEAKEN LATE IN THE EVENING
THRU THE OVERNIGHT, AND TEMPS WILL FALL WELL INTO THE TEENS ACROSS
MOST OF THE PIEDMONT, AND SINGLE DIGITS IN THE MOUNTAINS. THESE
TEMPS COMBINED WITH LINGERING WINDS WILL BRING WIND CHILLS BELOW
ZERO ACROSS MOST OF THE MOUNTAINS, AND SINGLE DIGITS TO LOWER
TEENS ACROSS THE PIEDMONT. A COLD WEATHER ADVISORY WILL BE ISSUED
FOR THE NC MOUNTAINS ABOVE 3500 FT AND ALL OF AVERY COUNTY. THE
PIEDMONT CRITERIA ARE MORE COMPLICATED, WITH THE FOOTHILLS AND NW
NC PIEDMONT NEEDING 5 DEGREES OR LESS, WHILE THE SOUTHERN/LOWER
PIEDMONT ONLY NEEDS 10 DEGREES OR LESS. EVEN BUMPING UP WINDS WITH
THE 75TH PERCENTILE OF THE NBM, WIND CHILLS STRUGGLE TO MEET THESE
CRITERIA, EXCEPT FOR PORTIONS OF THE I-77 CORRIDOR. GIVEN THIS IS
STILL IN THE THIRD PERIOD OF THE FORECAST, WILL HOLD OFF ON ISSUING
ANY COLD ADVISORY OUTSIDE THE MOUNTAINS WITH THIS FORECAST PACKAGE.
WINDS SHOULD BECOME LIGHT AND SKIES REMAIN CLEAR MAKING IT LOOK
DECEPTIVELY NICE ON MONDAY. BUT THE ARCTIC AIR MASS WILL SETTLE
RIGHT OVER THE AREA AND KEEP TEMPS MAINLY IN THE 30S TO LOWER
40S, WHICH IS 15-20 DEGREES BELOW NORMAL FOR MID-DECEMBER. THE
HIGH WILL BEGIN TO SLIDE EAST MONDAY NIGHT, ALLOWING FOR DECENT
WAA ALOFT. STILL SHOULD SEE GOOD RADIATIONAL COOLING AND BRING
LOW TEMPS INTO THE 20S AREA-WIDE. WITH LIGHT WINDS, WIND CHILLS
SHOULDN'T BE AN ISSUE.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/
AS OF 1215 PM EST SATURDAY:
KEY MESSAGE: TEMPERATURES REBOUND AND DRY CONDITIONS SETTLE IN
BEFORE PRECIP CHANCES INCREASE BY THE END OF THE WEEK.
ARCTIC HIGH PRESSURE SLIDES OFF THE EAST COAST UNDER QUASI-ZONAL
FLOW ALOFT TUESDAY, ALLOWING FOR A NICE REBOUND IN TEMPS AND
CONTINUED DRY WEATHER. HIGHS RETURN TO LOWER TO MID 50S (EXCEPT
40S ABOVE 3500 FT) AND LOWS IN THE UPPER 20S TO MID 30S. THERE
MAY BE PERIODS OF INCREASED MID AND HIGH CLOUDS STREAMING THRU
WESTERLY FLOW, BUT OVERALL, MOSTLY CLEAR SKIES IS EXPECTED. THE
12Z GFS TRIES TO BRING A FEW SHOWERS TO THE MOUNTAINS FROM THE
WEST WEDNESDAY, BUT THIS SEEMS OVERDONE COMPARED TO THE REST OF
THE MODELS. BETTER RAIN CHANCES MAY RETURN LATE THURSDAY THRU
EARLY FRIDAY, AS MODELS ARE COMING INTO BETTER AGREEMENT ON A
COLD FRONT APPROACHING FROM THE WEST. TEMPS WARM TO SLIGHTLY ABOVE
NORMAL WEDNESDAY THRU THURSDAY, SO PRECIP SHOULD BE LARGELY JUST
RAIN. THE AIR MASS BEHIND THIS FRONT LOOKS MILD AND ONLY KNOCKS
TEMPS DOWN TO AROUND NORMAL FRIDAY INTO NEXT WEEKEND.
AVIATION /18Z SATURDAY THROUGH THURSDAY/
AT KCLT AND ELSEWHERE: VFR IS FORECAST THROUGH MUCH OF THE
PERIOD. THE ONLY EXCEPTION WILL BE WITHIN A BRIEF WINDOW FROM
~09Z THRU ~15Z SUNDAY, WHEN MOISTURE WILL INCREASE IMMEDIATELY
AHEAD OF AN ARCTIC COLD FRONT. LOW VFR AND MVFR CIGS ARE EXPECTED
TO ACCOMPANY THIS MOISTURE...WITH RESTRICTIONS BEING MOST LIKELY
AT THE NC TERMINALS. A BRIEF SHOWER WILL ALSO BE POSSIBLE...BUT
PROBABILITIES ONLY SUPPORT PROB30S AT MOST. MAINLY LIGHT SW WINDS
OF 5-10 KTS THIS AFTERNOON WILL SHIFT TO NW AND INCREASE BEGINNING
AROUND 09Z SUNDAY, WITH GUSTS INCREASING THROUGH THE MORNING...TO 30-
35 KTS AT KAVL AND MOSTLY AROUND 25 KTS ELSEWHERE.
OUTLOOK: GUSTY N/NW WINDS WILL DIMINISH SUNDAY NIGHT INTO DAYBREAK
MONDAY. DRY HIGH PRESSURE WILL KEEP VFR CONDITIONS IN PLACE THROUGH
MID-WEEK. THE NEXT COLD FRONT WILL BRING SHOWER CHANCES AND POSSIBLY
RESTRICTIONS BY THURSDAY.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...COLD WEATHER ADVISORY FROM 5 PM SUNDAY TO 9 AM EST MONDAY FOR
NCZ033-048>053-058-059.
SC...NONE.
SYNOPSIS...ARK
NEAR TERM...JDL
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...JDL
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