264
FXUS62 KGSP 250557
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
157 AM EDT FRI SEP 25 2026
WHAT HAS CHANGED
THE AVIATION FORECAST WAS UPDATED TO REFLECT THE 06Z TAF ISSUANCE.
KEY MESSAGES
1. LINGERING SHOWERS WILL TAPER OFF BY EVENING AS DRIER STARTS
MOVING IN, BUT PATCHY DENSE FOG IS POSSIBLE THROUGH LATE
TONIGHT. OTHERWISE, TEMPERATURES REMAIN COOL FRIDAY BEFORE
RETURNING TO NORMAL THROUGH THE WEEKEND.
DISCUSSION
KEY MESSAGE 1: LINGERING SHOWERS WILL TAPER OFF BY EVENING AS DRIER
STARTS MOVING IN, BUT PATCHY DENSE FOG IS POSSIBLE THROUGH LATE
TONIGHT. OTHERWISE, TEMPERATURES REMAIN COOL FRIDAY BEFORE RETURNING
TO NORMAL THROUGH THE WEEKEND.
THE LOSS OF DAYTIME HEATING AND ANY PALTRY INSTABILITY OVER
THE SMOKIES AND BALSAMS HAS BROUGHT SHOWERS TO HEEL FOR THE
EVENINGS...SO STILL EXPECTING A DRY NIGHT AHEAD. STILL SEEING
WIDESPREAD LOW CLOUDS EAST OF THE MOUNTAINS, BUT THERE ARE HINTS
ALREADY OF THAT MOISTURE BEGINNING TO SCOUR OUT...WITH SATELLITE
IMAGERY DEPICTING DRYING AND CLEARING NORTH OF I-40 AND DRAWING
CLOSER.
THE WEDGE SHOULD START BREAKING DOWN AS WE GET INTO THIS EVENING
AND THE UPPER LOW OVER WV THIS PAST MORNING ROTATES SOUTHEASTWARD
ACROSS THE CAROLINAS THROUGH THE END OF THE DAY. ONCE THIS HAPPENS,
THE FLOW BACKING MORE NORTHERLY AND NORTHWESTERLY WILL DRAIN THE
COOL POOL EAST OF THE MTNS AND THAT WILL BE IT, WITH MOST OF THE
SKY BECOMING CLEAR BY DAYBREAK. THE ONLY MINOR PROBLEM COULD
BE THE POTENTIAL FOR SOME DENSE FOG TO DEVELOP AS THE DRY AIR
COMES IN ALOFT FIRST AND WE HAVE PLENTY OF LINGERING MOISTURE
AT THE SFC. MANY TIMES IN SIMILAR SITUATIONS, WE GET A PERIOD
OF A FEW HOURS WHERE PATCHY DENSE FOG DEVELOPS, SOMETIMES TO THE
POINT WHERE A DENSE FOG ADVISORY NEEDS TO BE ISSUED. THE GUIDANCE
DOESN'T SUPPORT IT RIGHT NOW, BUT THE POSSIBILITY EXISTS AND WE
WILL MONITOR FOR FOG DEVELOPMENT AFTER DARK.
FROM FRIDAY ONWARD, IT LOOKS LIKE SMOOTH SAILING. THE MODELS SHOW
US TRAPPED UNDER A COOL AND DRY CYCLONIC N TO NW FLOW ALOFT THROUGH
AT LEAST MONDAY, WHICH WILL PRECLUDE ANY RAIN. TEMPS STAY COOL ON
FRIDAY WITH HIGHS AROUND FIVE DEGREES BELOW NORMAL, AND PERHAPS
DOWNRIGHT CHILLY FOR LOW TEMPS EARLY SATURDAY MORNING WITH LOTS OF
PLACES DROPPING DOWN TO 45-50 DEGREES. RIDGETOPS ABOVE 5000 FEET
COULD GET DOWN IN THE UPPER 30S! THE SFC HIGH RESPONSIBLE FOR THIS
COOL-DOWN WILL BE STUCK TO OUR NORTH THROUGH THE WEEKEND AS IT WILL
BE BLOCKED BY THE BIG CUTOFF LOW OVER THE NORTHEAST, SO AS A RESULT
THE AIR MASS WILL REMAIN IN-PLACE AND SHOULD SLOWLY MODIFY WITH
TEMPS RETURNING TO SEASONAL NORMALS OVER THE WEEKEND. IT SHOULD BE
SPECTACULAR EARLY AUTUMN WEATHER. THE PATTERN GETS UN-STUCK DURING
THE MIDDLE PART OF THE WEEK WITH WARMER TEMPERATURES, BUT BY THEN,
MODEL DIFFERENCES INJECT A GREAT DEAL OF UNCERTAINTY INTO THE
FORECAST. EVENTUALLY AS WE GET INTO THE LATTER HALF OF THE NEXT
WEEK, RAIN CHANCES WILL RETURN AS MOISTURE COMES BACK UP FROM THE
SOUTH, BUT DETAILS ARE VERY SKETCHY.
AVIATION /06Z FRIDAY THROUGH TUESDAY/
AT KCLT AND ELSEWHERE: WE'VE STILL GOT LINGERING MVFR CIGS
OVER SOME OF THE UPSTATE TERMINALS, AS WELL AS, KHKY AND
KAVL. OVER THE NEXT FEW HRS, THESE CIGS SHOULD CONTINUE TO
SCT OUT OVER THE UPSTATE AND KHKY. THE MAIN EXCEPTION WILL
BE THE MOUNTAIN VALLEYS, WHERE MOST OF THE LATEST GUIDANCE
CONTINUES TO DEVELOP FOG OVERNIGHT AND INTO THE MORNING. IT'S
LOOKING LIKE THE FOG/LOW STRATUS WILL REACH KAVL, THUS I HAVE
PREVAILING IFR RESTRICTIONS BEGINNING AROUND 08Z WITH A TEMPO
FOR LIFR FROM 09 TO 13Z. RESTRICTIONS THERE SHOULD DISSIPATE
BY 13 OR 14Z THIS MORNING. KHKY AND THE UPSTATE TERMINALS COULD
ALSO SEE SOME BRIEF RESTRICTIONS OVERNIGHT AND INTO THE MORNING,
BUT CONFIDENCE IS FAIRLY LOW. OTHERWISE, A CLEAR, DRY DAY WITH
N TO NE WINDS IS EXPECTED TODAY/TONIGHT WITH WINDS BECOMING
LIGHT LATER TONIGHT.
OUTLOOK: DRY, VFR CONDITIONS SHOULD PERSIST INTO THE MIDDLE
OF NEXT WEEK, HOWEVER MOUNTAIN/RIVER VALLEY FOG/LOW STRATUS
WILL BE POSSIBLE EACH MORNING.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
AR/JPT
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