829
FXUS62 KGSP 040523
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1223 AM EST SUN JAN 4 2026
SYNOPSIS
TEMPERATURES REMAIN ABOVE NORMAL AND RAIN CHANCES REMAIN LOW UNTIL
A COLD FRONT ARRIVES AT THE END OF THE WEEK.
NEAR TERM /THROUGH TONIGHT/
AS OF 1055 PM SATURDAY:
KEY MESSAGE #1: DENSE FOG POSSIBLE OVERNIGHT INTO EARLY SUNDAY
MORNING FOLLOWED BY SEASONABLE TEMPERATURES BENEATH MOSTLY SUNNY
SKIES.
BROAD NORTHWEST FLOW BECOMES ESTABLISHED ACROSS THE REGION TODAY AS
NORTHERN STREAM FLOW REMAINS DRAPED ACROSS THE GREAT LAKES INTO NEW
ENGLAND. AT THE SAME TIME, SURFACE HIGH PRESSURE WILL DROP INTO THE
OHIO VALLEY AND SEND DRIER AIR INTO THE SOUTHERN APPALACHIANS. THE
MAIN FOCUS WILL BE THE POTENTIAL FOR DENSE FOG OVERNIGHT INTO EARLY
SUNDAY MORNING, ESPECIALLY WITHIN THE MOIST BOUNDARY LAYER ALONG AND
SOUTH OF I-85 WHERE THE GREATEST RAINFALL OCCURRED LAST NIGHT. A
DENSE FOG ADVISORY MAY EVENTUALLY BE WARRANTED SHOULD COVERAGE
INCREASE. ANY FOG SHOULD QUICKLY MIX OUT AFTER SUNRISE WITH A RETURN
TO MOSTLY SUNNY SKIES THROUGH THE DAY WITH TEMPERATURES WARMING TO
AT OR JUST ABOVE SEASONAL AVERAGES FOR EARLY JANUARY. TRANQUIL
CONDITIONS CONTINUE INTO TONIGHT WITH AN UPTICK IN CLOUD COVER BUT
NO PRECIPITATION OF MENTION.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/
AS OF 1100 PM SAT:
KEY MESSAGE: TEMPERATURES MONDAY WILL BE KEPT AT LEAST SLIGHTLY
COOLER DUE TO CLOUD COVER, BUT TREND WARMER AND WELL ABOVE NORMAL
TUESDAY.
SOME HIGH ALTITUDE CLOUD COVER IS EXPECTED TO SPREAD OVER THE AREA
SUNDAY NIGHT IN ASSOCIATION WITH WEAK SHORTWAVE NEAR THE GREAT LAKES
AND/OR WITH JET STREAKS ON THE DOWNSTREAM SIDE OF THE 250MB RIDGE
CENTERED OVER THE PLAINS. AT THE SURFACE, ATTENDANT HIGH PRESSURE
WILL CENTER OVER THE EAST COAST BY EARLY MONDAY MORNING. SW'LY
925-850MB FLOW WILL OCCUR OVER THE HIGH AND LIKELY WILL RESULT IN AN
AREA OF LOW STRATUS ALONG AND SOUTHEAST OF THE BLUE RIDGE ESCARPMENT,
IN A WEDGELIKE CONFIGURATION. A FEW SPRINKLES COULD RESULT
UNDER THIS DECK, BUT THE FORCING AND MOISTURE APPEAR TOO WEAK
FOR A MENTIONABLE POP. MOST GUIDANCE DEPICTING THE CLOUDS SHOW
THEM LINGERING THROUGH THE MORNING, DELAYING WARMING AND
IMPACTING MAX TEMPS AT LEAST SLIGHTLY. THE NAM HANGS ONTO THE
CLOUD COVER LONGER AND SUGGESTS HIGHS WILL BE HELD AT OR BELOW
NORMAL FOR A GOOD BIT OF THE PIEDMONT, THOUGH WITH THE MAJORITY
OF OTHER MODELS SHOWING THE EARLIER CLEARING AND THE OTHERWISE
WARM NATURE OF THE PATTERN, IT WOULD APPEAR WARMING WOULD BE
RAPID ENOUGH TO ALMOST ENTIRELY MAKE UP FOR THE MORNING CLOUDS,
SO ONLY A 2-3 DEGREE HIT COMPARED TO SUNDAY LOOKS APPROPRIATE
WITHIN THE CLOUDIEST AREA.
THE WEDGELIKE HIGH WILL REMAIN TRANSIENT AND MOVE OFFSHORE MONDAY
NIGHT AND TUESDAY, WHILE SOUTHWEST LOW-LEVEL FLOW CONTINUES AHEAD OF
A WEAK FRONT TRAILING THE NEXT SHORTWAVE PASSING BY TO OUR NORTH.
ANOTHER NOCTURNAL STRATUS EVENT CANNOT BE RULED OUT IN OUR NORTHERN
PIEDMONT ZONES IN THIS PATTERN, BUT REGARDLESS ALTO/CIRRUS CLOUDS
WILL BE MORE NUMEROUS. WITH THAT AND INCREASING THICKNESSES, TUESDAY
MORNING WILL START OUT SLIGHTLY THAN MONDAY, AND THE LESSER IMPACT OF
CLOUDS WILL BRING MAXES 5-10 DEGREES WARMER AS WELL.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
AS OF 1210 AM SUN:
KEY MESSAGE 1: TEMPERATURES REMAIN CONSIDERABLY ABOVE NORMAL THROUGH
THE REST OF THE WORKWEEK; NEAR-RECORD HIGHS EXPECTED WEDNESDAY.
SHORTWAVE AND WEAK FRONT WILL PASS TUESDAY NIGHT AND 925-850MB FLOW
WILL TURN WESTERLY ACROSS THE AREA; FORCING/MOISTURE APPEAR
INSUFFICIENT FOR A MENTIONABLE POP EAST OF THE MOUNTAINS THRU
WEDNESDAY. CAA BEHIND THE FRONT WILL BE WEAK AND SHORT-LIVED. SLIGHT
HEIGHT RISES AND WEAK DOWNSLOPING SHOULD PROMOTE WARMING OVER THE
AREA WED; THE AIRMASS WILL CONTINUE TO MODIFY AND TEMPS REACH THE
LOWER 70S ACROSS MUCH OF THE PIEDMONT, WITHIN A FEW DEGREES OF
RECORDS AT CLT AND AVL WHERE THE RECORDS ARE OUTLIERS COMPARED TO
SURROUNDING DAYS. GSP'S RECORD OF 71 COULD BE TIED. THURSDAY AND
LIKELY FRIDAY TREND SLIGHTLY COOLER ACROSS THE AREA DUE TO INCREASED
CLOUD COVER, THOUGH GIVEN ANOMALOUS HEIGHTS AND TEMPS ALOFT, MINS AND
MAXES REMAIN ON THE ORDER OF 15 ABOVE NORMAL NONETHELESS.
KEY MESSAGE 2: COLD FRONT BRINGS WIDESPREAD RAIN CHANCES FRIDAY AND
SATURDAY, WITH COOLER WEATHER FOLLOWING FOR SATURDAY NIGHT AND
SUNDAY.
PHASING SHORTWAVES INVOF THE ROCKIES COME TOGETHER INTO A
FULL-LATITUDE UPPER TROUGH BY LATE THURSDAY. THIS WILL PROMOTE
CYCLOGENESIS IN THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY,
ALONG THE BAROCLINIC ZONE ON THE PERIPHERY OF THE SUBTROPICAL RIDGE
OVER THE GULF. HENCE, INCREASING CLOUD COVER FOR OUR AREA THU AND
ESPECIALLY THU NIGHT AND FRI AS HINTED ABOVE. THE BULK OF THE PRECIP
PRODUCED ALONG THE SYSTEM'S WARM FRONT CURRENTLY LOOKS TO FALL TO OUR
NORTH AND WEST, WITH THE LOW TRACKING NEAR/ALONG THE OHIO RIVER.
HOWEVER, CONSENSUS BRINGS THE COLD FRONT INTO THE CWA, AND POPS REACH
THE 30-50% RANGE FOR ALL AREAS FRIDAY AND FRIDAY NIGHT. A 40-50 KT
LLJ COULD PRECEDE THE FRONT; NOT YET CONFIDENT THIS WILL OVERLAP WITH
ENOUGH INSTABILITY TO FOSTER THUNDER AND/OR SEVERE WIND THREAT, BUT
THAT WILL HAVE TO BE MONITORED ON SUBSEQUENT FORECASTS. POPS DECLINE
LATE SATURDAY BUT DUE TO MODEL SPREAD THEY REMAIN MENTIONABLE (ABOVE
20%) IN MOST AREAS THROUGH THE END OF THE PERIOD SUNDAY MORNING.
TEMPS TREND COOLER SATURDAY NIGHT, AND NW FLOW SNOW COULD RESULT IN
THE MOUNTAINS BEHIND THE FRONT.
AVIATION /06Z SUNDAY THROUGH THURSDAY/
AT KCLT AND ELSEWHERE: THE MAIN FOCUS THROUGH THE TAF PERIOD WILL BE
THE POTENTIAL FOR FOG TO DEVELOP OVERNIGHT INTO EARLY SUNDAY
MORNING. THE BEST CHANCES FOR FOG WILL BE ALONG AND SOUTH OF I-85 AT
KAND/KGSP/KGMU WHERE THE LOWER PORTIONS OF THE ATMOSPHERE ARE MOST
SATURATED FROM LAST NIGHT'S RAINFALL. A FEW INSTANCES OF LOCALLY
DENSE FOG CANNOT BE RULED OUT, BUT CONFIDENCE ON WHERE AND WHEN
REMAINS TOO LOW TO WARRANT MENTION AT ANY GIVEN TERMINAL. FOG WILL
MIX OUT FAIRLY QUICKLY AFTER SUNRISE WITH A RETURN TO VFR CONDITIONS
FOR THE REMAINDER OF THE TAF PERIOD. WINDS WILL BE LIGHT AND
VARIABLE THROUGH THE PERIOD AS SURFACE HIGH PRESSURE SLIDES INTO THE
REGION.
OUTLOOK: DRY, VFR CONDITIONS ARE EXPECTED TO PERSIST THRU THE MIDDLE
OF NEXT WEEK.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
SYNOPSIS...JCW
NEAR TERM...TW
SHORT TERM...JCW
LONG TERM...JCW
AVIATION...JPT/TW
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