259
FXUS62 KGSP 070643
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
143 AM EST SUN DEC 7 2025
SYNOPSIS
COOL HIGH PRESSURE MOVES IN TODAY, THEN AN UPPER LEVEL
DISTURBANCE ARRIVES LATE TONIGHT AND BRINGS THE POTENTIAL FOR LIGHT
PRECIPITATION THROUGH MONDAY. DRY CONDITIONS RETURN BY MIDWEEK WITH
NORMAL TEMPERATURES. A COLD FRONT SHOULD ARRIVE LATE IN THE WEEK.
NEAR TERM /THROUGH TONIGHT/
AS OF 1:15 AM EST SUNDAY...
KEY MESSAGE 1: A DENSE FOG ADVISORY REMAINS IN EFFECT OUTSIDE OF
THE NC MOUNTAINS THRU 10 AM THIS MORNING.
AREAS OF DENSE FOG HAVE DEVELOPED ACROSS MOST OF OUR NON-MTN ZONES
OVER THE PAST FEW HRS. THE FOG SHOULD BEGIN TO DISSIPATE BY MID-
MORNING, BUT COULD LINGER THRU LATE MORNING AT SOME SITES. THERE
IS SOME CONCERN THAT FREEZING FOG MAY DEVELOP IN THE NW PIEDMONT,
WHERE TEMPS ARE HOVERING NEAR FREEZING. HOWEVER, WITH ROADS STARTING
OUT RELATIVELY WARM AND TEMPERATURES LOOKING MARGINAL, CONFIDENCE IS
FAIRLY LOW THAT IT WILL MATERIALIZE. IF FREEZING FOG BECOMES MORE
WIDESPREAD, A FREEZING FOG ADVISORY MAY BE NEEDED FOR PARTS OF THE
I-40 CORRIDOR THIS MORNING.
OTHERWISE...DRY HIGH PRESSURE WILL CONTINUE BUILDING INTO THE REGION
WHILE AN UPPER TROF PUSHES EAST OF OUR FCST AREA BY LATE THIS EVENING.
CLOUD COVER WILL CONTINUE TO GRADUALLY INCREASE OVERNIGHT, ESPECIALLY
EAST OF THE MTNS. DESPITE THE CLOUD COVER, IT WILL BE A COLD NIGHT
WITH TEMPERATURES FALLING NEAR TO BELOW FREEZING ACROSS OUR FCST AREA.
THE SFC HIGH WILL BE OVERHEAD TODAY ALLOWING SOMEWHAT DRIER AND WARMER
CONDITIONS TO DEVELOP. NONETHELESS, HIGH TEMPS ARE STILL EXPECTED TO
REMAIN ROUGHLY 4 TO 8 DEGREES BELOW NORMAL THANKS TO LINGERING CLOUD
COVER. ANOTHER ROUND OF DENSE FOG MAY DEVELOP LATER TONIGHT INTO EARLY
MONDAY THANKS TO CALM WINDS AND LINGERING LOW-LEVEL MOISTURE, BUT IT'S
LIKELY TO BE MORE PATCHY THAN WHAT WE'RE CURRENTLY OBSERVING.
KEY MESSAGE 2: ANOTHER WEAK LOW PRESSURE SYSTEM WILL DEVELOP TO OUR
SOUTH LATER THIS EVENING AND INTO MONDAY. THIS SYSTEM IS EXPECTED TO
BRING LIGHT SNOW ACCUMULATIONS TO PORTIONS OF THE NC MOUNTAINS AND
RAIN ELSEWHERE ACROSS OUR FCST AREA. AS SUCH, A WINTER WX ADVISORY
HAS BEEN ISSUED FOR ACCUMULATING SNOW FOR THE NORTHERN NC MOUNTAINS.
THE ADVISORY IS IN EFFECT FROM 1 AM MONDAY UNTIL 1 AM TUESDAY.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/
KEY MESSAGES:
1) LIGHT SNOW WILL CONTINUE AT HIGH ELEVATIONS ACROSS PORTIONS OF
THE MOUNTAINS ON MONDAY, WITH COLD RAIN ELSEWHERE.
2) THE PRECIP COULD CHANGE TO LIGHT SNOW ACROSS THE NORTHERN
FOOTHILLS AND NORTHWEST PIEDMONT BEFORE ENDING ON MONDAY, BUT THE
POTENTIAL FOR ACCUMULATION LOOKS MINIMAL AT THIS TIME.
3) DRY CONDITIONS RETURN TUESDAY WITH BELOW NORMAL TEMPERATURES.
AS OF 125 AM EST SUNDAY: WE SHOULD BE IN THE MIDDLE OF A SHORT WAVE
TRAVERSING THE REGION AT DAYBREAK MONDAY, WHICH THE GUIDANCE HAS
BEEN FAIRLY CONSISTENT IN HANDLING. WHAT REMAINS INCONSISTENT,
HOWEVER, IS THE EXTENT OF WINTRY PRECIP IN THE MODEL GUIDANCE,
WITH THE GFS CONTINUING TO LOOK OVERLY OPTIMISTIC (IF YOU WANT LOTS
OF SNOW). AGAIN, THE QPF IN THAT MODEL LOOKS OVERDONE IN LIGHT
OF THE FORCING CONFINED MAINLY TO MID-LEVELS. THE TIMING OF THE
WAVE CONTINUES TO BE SUCH THAT MOST OF THE PRECIP POTENTIAL WILL
BE CARRIED OFF TO THE EAST BY THE MIDDLE PART OF THE DAY BEFORE
THE COLD AIR REALLY HAS THE CHANCE TO MAKE A SERIOUS PUSH FROM
THE NORTH, THOUGH THE GFS CERTAINLY TRIES. CONFIDENCE IS HIGH
ENOUGH ACROSS THE HIGH ELEVATIONS OF THE NRN MOUNTAINS TO ISSUE
AN ADVISORY FOR SNOW STARTING EARLY MONDAY BECAUSE THAT PART OF
THE FCST AREA IS LESS DEPENDENT ON THE TIMING OF THE COLD AIR
SURGE. THERE SHOULD BE ENOUGH PRECIP POTENTIAL TO BRING THE SNOW
TOTALS UP INTO THE 1-3 RANGE IN THAT AREA. THE REST OF THE MTNS
JUST DON'T HAVE ENOUGH IN THE QPF TO WARRANT AN ADVISORY. EAST OF
THE MTNS...THERE ARE TOO MANY LIMITING FACTORS RELATED TO THE TIME
OF POTENTIAL CHANGEOVER, THE PRECIP AMOUNTS, AND DURATION. WHAT IS
MOST LIKELY IS THAT THE COLD AIR CHASES THE BACK EDGE OF THE PRECIP
EAST OF THE MTNS ACROSS THE NRN FOOTHILLS AND NORTHWEST PIEDMONT
AND WE GET A BRIEF PERIOD OF LIGHT SNOW IN THE MID/LATE AFTERNOON
THAT PRODUCES A DUSTING OR LESS THAN AN INCH. SORRY, JUST A COLD
RAIN ACROSS THE UPSTATE AND NORTHEAST GA OUTSIDE THE MTNS. TEMPS
WILL REMAIN BELOW NORMAL BECAUSE OF THE CLOUDS AND PRECIP...WELL
BELOW OVER THE NRN TIER. THE PRECIP MOVES OUT COMPLETELY BY SUNSET
EAST OF THE MTNS, BUT COULD LINGER OVER THE NRN MOUNTAINS INTO
THE EVENING, SO THE ADVISORY WILL RUN THROUGH 06Z TUESDAY.
WITH THAT OUT OF THE WAY BY DAYBREAK TUESDAY, HIGH PRESSURE SHOULD
BUILD IN TUESDAY AND WE SHOULD FINALLY SEE SOME SUN AGAIN, BUT
HIGH TEMPS WILL BE ON THE ORDER OF TEN DEGREES UNDER NORMAL. THE
PATTERN MOVES RIGHT ALONG, THOUGH, WITH THE HIGH CENTER MOVING
OFF TO THE EAST TUESDAY NIGHT ALLOWING FOR SOME WARM ADVECTION TO
COMMENCE ALOFT OVERNIGHT. SO, LOW TEMPS TUESDAY NIGHT WILL ONLY
BE SLIGHTLY UNDER NORMAL.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
KEY MESSAGES
1) FAIR BUT BREEZY WEDNESDAY WITH NEAR NORMAL TEMPERATURES.
2) LOW CONFIDENCE IN PRECIP ASSOCIATED WITH A COLD FRONT THAT
MOVES THROUGH LATE IN THE WEEK.
3) BEHIND THE FRONT, A POTENTIAL COLD WAVE NEXT WEEKEND WITH
TEMPERATURES RUNNING AROUND 15 DEGREES BELOW NORMAL.
AS OF 1251 AM EST SUNDAY: THE QUIETEST DAY CONTINUES TO LOOK LIKE
WEDNESDAY, BUT A CLIPPER LOW MOVING ACROSS THE GREAT LAKES IN THE
FAST-MOVING BROADLY CYCLONIC FLOW ALOFT STILL LOOKS LIKE IT WILL
BRING US A BREEZY DAY. GUIDANCE CONTINUES TO SHOW A SOUTHWESTERLY
LOW LEVEL JET TRANSLATING EAST ACROSS THE REGION DURING THE
DAY WHEN WE WILL BE ABLE TO MIX DOWN SOME OF THE HIGHER MOMENTUM
AIR. THE RESULTING WARM ADVECTION SHOULD ALLOW TEMPS TO CLIMB BACK
UP CLOSE TO NORMAL. FORTUNATELY, THE RH SHOULD STAY HIGH ENOUGH TO
ALLEVIATE MOST FIRE WEATHER CONCERNS. THE BREEZY CONDITIONS SHOULD
TAPER OFF WEDNESDAY NIGHT AS THE LOW LEVEL JET MOVES AWAY AND THE
GRADIENT TEMPORARILY RELAXES. BEYOND THAT, CONFIDENCE FOR THE LATE
PART OF THE WORK WEEK IS ON A DOWNWARD TREND BECAUSE THE GUIDANCE
SUFFERS FROM CONSISTENCY ISSUES REGARDING THE POTENTIAL FOR THE
NEXT CLIPPER-LIKE WAVE DROPPING THROUGH THE BROAD UPPER TROF,
WHICH LEADS TO MULTIPLE SCENARIOS. SO, IT BECOMES MORE DIFFICULT
TO SAY WHEN A SFC COLD FRONT WILL GET PUSHED ACROSS THE REGION OR
HOW MUCH MOISTURE WILL BE AVAILABLE FOR PRECIP. ODDLY ENOUGH, THE
MODEL BLEND APPEARS MORE CONFIDENT THAN I AM WITH THE MAIN PRECIP
POTENTIAL LATE THURSDAY THROUGH FRIDAY. THE COLD AIR LOOKS LIKE
IT WILL REMAIN WELL BEHIND ANY BOUNDARY THAT WOULD MOVE THROUGH
WITH THE PRECIP, SO WE ARE LOOKING AT MAINLY RAIN, WITH SOME VERY
HIGH ELEVATION MINIMAL SNOW POTENTIAL. NO BIG DEAL.
THE BIG DEAL, HOWEVER, WILL BE THE TEMPERATURES BEHIND THE BOUNDARY
WHEN IT FINALLY DOES MOVE THROUGH. THE OVERALL PATTERN LOOKS MORE
LIKE TYPICAL DEAD-OF-WINTER OVER THE EAST WITH A DEEP MID/UPPER LOW
OVER EASTERN CANADA, WHICH WOULD SUPPORT A LARGE ARCTIC SFC HIGH
DROPPING DOWN ACROSS THE PLAINS ON SATURDAY AND OVER THE SOUTHEAST
ON SUNDAY. THIS PATTERN WOULD SUPPORT A PERIOD OF LIGHT NW FLOW SNOW
ON THE TN BORDER FRIDAY NIGHT, BUT MORE IMPORTANTLY WOULD BRING
A COLD AIR MASS ACROSS OUR REGION FOR THE WEEKEND. TEMPS WOULD BE
ON THE ORDER OF 15 DEGREES BELOW NORMAL IN SPITE OF CLEAR SKY. BRRR.
AVIATION /06Z SUNDAY THROUGH THURSDAY/
AT KCLT AND ELSEWHERE: AREAS OF DENSE FOG HAVE DEVELOPED OVER
THE AREA DURING THE PAST FEW HRS, WITH MOST SITES CURRENTLY
REPORTING 1/4 TO 1/2 SM VISBY AND CIGS BETWEEN 100 AND 300 FT.
SOME MTN VALLEY SITES ARE ALSO REPORTING FOG, BUT KAVL HAS YET
TO. NONETHELESS, I KEPT A TEMPO AT KAVL FOR SOME IFR CIGS/VSBY
AROUND DAYBREAK. THE CURRENT SETUP STILL LOOKS GOOD FOR WIDE-
SPREAD FOG TO PERSIST THRU LATE THIS MORNING. THE FOG/LOW STRATUS
SHOULD GRADUALLY LIFT LATE MORNING INTO EARLY AFTERNOON, BUT CON-
FIDENCE REMAINS FAIRLY LOW THAT MOST SITES WILL RETURN TO VFR
BEFORE MID TO LATE AFTERNOON TODAY. SOME AREAS MAY NOT SCT OUT
COMPLETELY BEFORE MVFR TO IFR CIGS, AND TO A LESSER EXTENT, MVFR
VISBY RETURN AGAIN LATER THIS EVENING. WINDS SHOULD REMAIN LIGHT
TO CALM THRU MOST OF THE PERIOD, BUT SOME SITES MAY FAVOR A S TO
SE DIRECTION THIS AFTERNOON.
OUTLOOK: A LOW PRESSURE SYSTEM WILL BRING PRECIP AND RESTRICTIONS
LATE SUNDAY NIGHT INTO MONDAY. DRY HIGH PRESSURE IS EXPECTED TO
SPREAD BACK OVER THE AREA TUESDAY INTO WEDNESDAY.
GSP WATCHES/WARNINGS/ADVISORIES
GA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR GAZ010-017-
018-026-028-029.
NC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR NCZ035>037-
056-057-068>072-082-501>510.
WINTER WEATHER ADVISORY FROM 1 AM MONDAY TO 1 AM EST TUESDAY
FOR NCZ033-049-050.
SC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR SCZ008>014-
019-101>109.
SYNOPSIS...PM
NEAR TERM...JPT
SHORT TERM...PM
LONG TERM...PM
AVIATION...JPT
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