696
FXUS62 KGSP 171032
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
632 AM EDT FRI JUL 17 2026
WHAT HAS CHANGED
UPDATED THE AVIATION DISCUSSION FOR THE 12Z TAFS.
KEY MESSAGES
1. HOT AND HUMID CONDITIONS LINGER THROUGH THE WEEKEND WITH HEAT
INDEX VALUES RANGING FROM 100 TO 105 DEGREES EACH AFTERNOON.
2. COVERAGE OF MAINLY DIURNAL SHOWERS AND THUNDERSTORMS WILL
INCREASE THROUGH WEEKEND AS A WEAK COLD FRONT MOVES THROUGH
OUR AREA.
DISCUSSION
KEY MESSAGE 1: HOT AND HUMID CONDITIONS LINGER THROUGH THE WEEKEND
WITH HEAT INDEX VALUES RANGING FROM 100 TO 105 DEGREES EACH
AFTERNOON.
BROAD UPPER RIDGING OVER THE AREA TODAY WILL SLOWLY WEAKEN THROUGH
THE WEEKEND AS MOVES INTO THE MID-ATLANTIC BY SUNDAY. HOT AND HUMID
CONDITIONS ARE EXPECTED TODAY WITH TEMPERATURES SLOWLY DROPPING INTO
SUNDAY WITH LOWER THICKNESS VALUES. THERE IS SOME POTENTIAL FOR A
BROAD PLUME OF SMOKE FROM WILDFIRES (WELL TO OUR NORTH) TO SPREAD
OVER OUR AREA TODAY, WHICH COULD SUPPRESS TEMPERATURES SOMEWHAT.
WHILE HIGHS WILL REACH THE MID TO UPPER 90S OUTSIDE OF THE
MOUNTAINS, THE DEWPOINTS REMAIN THE QUESTION. LATEST GUIDANCE
SUGGESTS LOWER DEWPOINTS WITH DEEP MIXING TODAY. THEREFORE, THE
PROBABILITY OF LARGE AREAS WITH A HEAT INDEX OF 105 OR HIGHER IS LOW.
THEREFORE, CONFIDENCE IS TOO LOW FOR A HEAT ADVISORY AT THIS TIME.
STILL, HEAT INDEX VALUES WILL LIKELY BE 100 OR HIGHER OUTSIDE OF THE
MOUNTAINS, SO INDIVIDUALS SHOULD PREPARE FOR ELEVATED HEAT RISK OVER
THE NEXT FEW DAYS. STAY HYDRATED, TAKE FREQUENT BREAKS IN AIR-
CONDITIONED OR SHADED AREAS, AND NEVER LEAVE CHILDREN OR PETS
UNATTENDED IN VEHICLES.
EVEN WITH TEMPERATURES FALLING INTO THE LOWER 90S BY SUNDAY,
DEWPOINTS HAVE LESS OF A CHANCE OF MIXING OUT. THEREFORE, HEAT INDEX
VALUES WILL LIKELY REMAIN ABOVE 100 SATURDAY AND SUNDAY. THIS IS
FOLLOWED BY A RETURN OF MORE TYPICAL HEAT INDEX VALUES FOR THE FIRST
HALF OF NEXT WEEK.
KEY MESSAGE 2: COVERAGE OF MAINLY DIURNAL SHOWERS AND THUNDERSTORMS
WILL INCREASE THROUGH WEEKEND AS A WEAK COLD FRONT MOVES THROUGH OUR
AREA.
WITH THE UPPER RIDGE OVER THE AREA TODAY, THE ATMOSPHERE REMAINS
RELATIVELY CAPPED WITH HIGH LFC'S OVER THE NC PIEDMONT AND EASTERN
UPSTATE. CONDITIONS WILL BE BETTER ACROSS THE MOUNTAINS AND SLIGHTLY
BETTER OVER THE WESTERN UPSTATE AND NE GEORGIA. A FEW OF THE STORMS
COULD BECOME SEVERE WITH DAMAGING WINDS THE MAIN THREAT.
WITH HEIGHTS FALLING ACROSS THE EASTERN CONUS THROUGH THE WEEKEND, A
COLD FRONT MOVES INTO THE AREA BY SUNDAY. EXPECT INCREASING
INSTABILITY, MOISTURE, AND SHEAR. THIS, ALONG WITH THE POTENTIAL
FOR SOME ORGANIZATION, WILL LEAD TO INCREASING CHANCES OF SEVERE
STORMS SATURDAY, WITH THE BEST CHANCE ON SUNDAY, ESPECIALLY OVER THE
I-77 CORRIDOR. DAMAGING WINDS REMAIN THE MAIN THREAT.
AFTER A DECREASE IN CONVECTIVE CHANCES BEHIND THE FRONT, ESPECIALLY
ON TUESDAY, THE CHANCE PICKS BACK UP WEDNESDAY AS ANOTHER FRONT
MOVES INTO THE AREA.
AVIATION /12Z FRIDAY THROUGH TUESDAY/
AT KCLT AND ELSEWHERE: MOUNTAIN VALLEY FOG/STRATUS LOOKS TO MISS
KAVL THIS MORNING. CIRRUS CONTINUES THROUGH THE DAY WITH VFR CU
DEVELOPING. TSRA EXPECTED ONCE AGAIN DURING THE AFTERNOON AND EARLY
EVENING WITH SLIGHTLY BETTER COVERAGE EXPECTED. HAVE RETAINED THE
PROB30S FOR TSRA AT KAVL AND THE SC UPSTATE TERMINALS. KCLT AND KHKY
SHOULD REMAIN DRY AGAIN. WINDS TURN MORE NORTHEASTERLY DURING THE
MORNING, NNW AT KAVL, THEN TURNS SOUTHERLY FOR THE AFTERNOON FOR ALL
BUT KAVL WHERE IT REMAINS NW. WINDS GO LIGHT AND VARIABLE DURING THE
EVENING. MAINLY CIRRUS OVERNIGHT, BUT MOUNTAIN VALLEY FOG/STRATUS
EXPECTED ONCE AGAIN.
OUTLOOK: EVEN BETTER COVERAGE OF AFTERNOON/EVENING SHRA/TSRA IS
EXPECTED THIS WEEKEND WITH A FEW STRONG TO SEVERE STORMS POSSIBLE
EACH DAY DURING PEAK HEATING HOURS. COVERAGE THEN DIMINISHES EARLY
NEXT WEEK. LOW STRATUS AND/OR FOG WILL BE POSSIBLE EACH MORNING,
MAINLY IN THE MOUNTAIN VALLEYS.
CLIMATE
RECORDS FOR 07-17
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAVL 95 1980 72 1917 77 1887 54 1939
1891
KCLT 100 1986 74 1989 80 1881 62 2004
1887 1896 1903
1886
KGSP 103 1887 76 1930 76 1934 60 1886
GSP WATCHES/WARNINGS/ADVISORIES
GA...NONE.
NC...NONE.
SC...NONE.
RWH
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