986
FXUS62 KGSP 120536
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
136 AM EDT WED AUG 12 2026
WHAT HAS CHANGED
HEAT INDICES ARE TRENDING SLIGHTLY WARMER FOR THE END OF THE WEEK.
UPDATED THE AVIATION DISCUSSION FOR THE 06Z TAFS.
KEY MESSAGES
1. SHOWERS AND THUNDERSTORMS POSSIBLE TODAY, WITH A FEW
BECOMING SEVERE. DAILY THUNDERSTORMS ARE ALSO POSSIBLE EACH
AFTERNOON THROUGH THE END OF THE WEEK.
2. HEAT BUILDS BY LATE WEEK INTO THE WEEKEND WITH TRIPLE DIGIT
HEAT INDICES RETURNING.
DISCUSSION
KEY MESSAGE 1: SHOWERS AND THUNDERSTORMS POSSIBLE TODAY, WITH A FEW
BECOMING SEVERE. DAILY THUNDERSTORMS ARE ALSO POSSIBLE EACH
AFTERNOON THROUGH THE END OF THE WEEK.
ANOTHER ROUND OF THUNDERSTORMS ARE POSSIBLE TODAY AS THE CWA REMAINS
DOWNSTREAM OF THE RIDGE OUT WEST. THE SEVERITY OF THESE STORMS IS
HIGHLY DEPENDENT ON HOW WORKED OVER THE ENVIRONMENT IS FROM PREVIOUS
ROUNDS OF SHOWERS AND THUNDERSTORMS. AT THIS TIME, MODEL GUIDANCE,
FOR WHAT ITS WORTH, SHOWS AN ENVIRONMENT WITH DECENT INSTABILITY (IF
IT CAN RECOVER) AND DCAPE BY THE EARLY AFTERNOON. BUT THIS DOES NOT
TAKE INTO ACCOUNT CLOUD DEBRIS AND HOW MUCH THE AIR CAN RECOVER. IF
IT CAN RECOVER, THERE IS A MARGINAL RISK (1 OUT OF 5) THAT A STORM
COULD BECOME STRONG OR SEVERE AS ANY REMNANT MCS MAKES ITS WAY
DOWNSTREAM. THIS IS ESPECIALLY THE FOCUS FOR THE MOUNTAINS.
CONFIDENCE IS LOW TO MEDIUM ON HOW OR WHERE THESE POTENTIAL ROUNDS
OF THUNDERSTORMS COULD OCCUR. AS FOR THE REMAINDER OF THE WEEK, THE
RIDGE STARTS TO SHIFT EASTWARD AND SHUTS OFF THE MCS CONVEYER BELT.
GIVEN THE OPEN WARM SECTOR REMAINING THROUGH THE END OF THE WEEK,
DAILY CHANCES FOR MORE TYPICAL SUMMERTIME SHOWERS AND THUNDERSTORMS
ARE LIKELY. THE HIGHER CHANCES ARE AS USUAL, OVER THE MOUNTAINS,
WITH A FEW POP UP SHOWERS POSSIBLE OUTSIDE THE MOUNTAINS. CHANCES
INCREASE OVER THE WEEKEND FOR A SIMILAR SITUATION.
KEY MESSAGE 2: HEAT BUILDS BY LATE WEEK INTO THE WEEKEND WITH TRIPLE
DIGIT HEAT INDICES RETURNING.
BY THURSDAY AND FRIDAY, THE RIDGE MAKES ITS WAY OVER THE SOUTHEAST
AND HIGH PRESSURE CONTINUES TO BUILD. WITH THESE HEIGHT RISES
RETURNING, SO DOES THE HOTTER TEMPERATURES. CURRENT GUIDANCE SHOWS
MID TO UPPER 90S FOR MOST LOCATIONS EAST OF THE MOUNTAINS ON
THURSDAY AND FRIDAY. GIVEN THE MOISTURE STILL HANGING AROUND,
DEWPOINTS ARE ALSO ELEVATED, WHICH MEANS HEAT INDEX VALUES OF 100-
103 OUTSIDE THE MOUNTAINS. FRIDAY COULD BE THE HOTTER OF THE TWO
DAYS WITH HEAT INDEX VALUES OF 101-105+ IN A FEW LOCATIONS IN THE
SOUTHERN ZONES AND NC PIEDMONT. CONFIDENCE IS INCREASING ON THESE
HOTTER HEAT INDEX VALUES BUT STILL ROOM FOR CHANGE. IF THE AXIS OF
THE RIDGE SLOWS DOWN, IT COULD LESSEN HOW MUCH THE HEIGHTS RISES,
AFFECTING THE TEMPS. SHOULD THE TREND FOR THESE HOTTER HEAT INDEX
VALUES CONTINUE, THERE MAY BE A NEED FOR A HEAT ADVISORY IN THE
SOUTHERN COUNTIES. THERE MAY BE A SMALL BOUNDARY THAT COMES THROUGH
OVER THE WEEKEND TO SLIGHTLY COOL THINGS DOWN, BUT CONFIDENCE IS
LOW. EXTENDED GUIDANCE SHOWS HEAT REMAINING TO START THE WEEK WITH
TRIPLE DIGIT HEAT INDEX VALUES POSSIBLE.
AVIATION /06Z WEDNESDAY THROUGH SUNDAY/
AT KCLT AND ELSEWHERE: ANOTHER ROUND OF VCSH AND RA THAT SHOULD
DIMINISH THROUGH 06Z-08Z, WITH ANOTHER ROUND OF TSRA WEDNESDAY LATE
MORNING/AFTERNOON. CONFIDENCE IS LOWER SO A PROB30 FOR NOW AT ALL
SITES. HEAVY RAINFALL AT KAVL INCREASES CONFIDENCE THAT IFR BR MAY
NOT OCCUR OVERNIGHT, BUT MVFR VSBY IS POSSIBLE 11Z-13Z IF RAIN ENDS.
OUTSIDE OF THE TSRA, WHICH COULD GIVE GUSTS OF 15-25KTS, LIGHT WINDS
OUT OF THE NW. BKN/SCT CIGS SHOULD REMAIN VFR OUTSIDE OF ANY TSRA OR
RA WEDNESDAY.
OUTLOOK: A FEW SHOWERS OR THUNDERSTORMS POSSIBLE EACH AFTERNOON WITH
FLIGHT RESTRICTIONS POSSIBLE FOR LOW STRATUS AND FOG EACH MORNING.
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
CP
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