016
FXUS62 KGSP 291051
AFDGSP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
651 AM EDT MON JUN 29 2026
WHAT HAS CHANGED
UPDATED THE AVIATION DISCUSSION FOR THE 12Z TAFS.
KEY MESSAGES
1. ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WEST OF I-26 POSSIBLE
THIS AFTERNOON AND EVENING, WITH ONE OR TWO STORMS POTENTIALLY
BECOMING STRONG TO SEVERE.
2. HEAT RISK WILL STEADILY INCREASE THROUGH THIS WEEK, WITH HEAT
INDICES LIKELY EXCEEDING 100 DEGREES ACROSS MUCH OF THE PIEDMONT
AND FOOTHILLS, ESPECIALLY BY MID TO LATE WEEK.
DISCUSSION
KEY MESSAGE 1: ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WEST OF I-26
POSSIBLE THIS AFTERNOON AND EVENING, WITH ONE OR TWO STORMS
POTENTIALLY BECOMING STRONG TO SEVERE.
MOST OF THE SHOWER AND THUNDERSTORM ACTIVITY OVERNIGHT OVER THE
SOUTHWEST MOUNTAINS HAS DISSIPATED. ANY LINGERING MOUNTAIN VALLEY
FOG AND LOW STRATUS WILL SCATTER OUT BY MID MORNING.
CONTINUED NORTHWEST FLOW ALOFT THANKS TO A DEEPENING UPPER-LEVEL
RIDGE TO THE WEST AND THE PRESENCE OF A WEAK FRONTAL BOUNDARY
DRAPED ALONG THE I-26 CORRIDOR, ISOLATED CONVECTIVE INITIATION
IS POSSIBLE DURING PEAK HEATING WEST OF I-26. CAMS VARY AS FAR AS
COVERAGE AND INTENSITY, BUT DEEP MOISTURE (PWAT >1.50"), SUFFICIENT
SBCAPE (2000-3000 J/KG), AND 20-30 KTS OF 0-6 KM BULK SHEAR ON THE
WEST SIDE OF THE BOUNDARY SUGGESTS THAT THE ENVIRONMENT COULD BE
ENOUGH TO SUPPORT LOOSELY ORGANIZED CONVECTION CAPABLE OF A STRONG
TO SEVERE THUNDERSTORM OR TWO, PRODUCING DAMAGING WINDS. GUIDANCE
CONTINUES TO PINPOINT THE WESTERN UPSTATE AS HAVING THE HIGHEST
PROBABILITY OF A SEVERE STORM, BUT CAN'T BE RULED OUT ELSEWHERE WEST
OF I-26. AFTERNOON HIGHS ARE FORECAST TO RUN A CATEGORY OR SO ABOVE
NORMAL, WITH THE SOUTHERN TIER OF THE CWFA POTENTIALLY EXCEEDING
100 DEGREE HEAT INDICES BEFORE ANY AFTERNOON CONVECTION ARRIVES.
KEY MESSAGE 2: HEAT RISK WILL STEADILY INCREASE THROUGH THIS WEEK,
WITH HEAT INDICES LIKELY EXCEEDING 100 DEGREES ACROSS MUCH OF THE
PIEDMONT AND FOOTHILLS, ESPECIALLY BY MID TO LATE WEEK.
AN UPPER-LEVEL RIDGE WILL STRENGTHEN ACROSS THE EASTERN CONUS THIS
WEEK, BRINGING A STEADY WARMING TREND AND SUPPRESSING CONVECTIVE
COVERAGE. HIGH TEMPERATURES ARE EXPECTED TO CLIMB INTO THE LOWER
TO MID 90S EAST OF THE MOUNTAINS TODAY AND TUESDAY, WITH VALUES
RUNNING 5-10 DEGREES ABOVE NORMAL BY MID TO LATE WEEK AND THE
INDEPENDENCE DAY HOLIDAY WEEKEND.
HEAT INDEX VALUES MAY APPROACH OR EXCEED 100 DEGREES STARTING
TODAY THROUGH WEDNESDAY, WITH POSSIBLE HEAT ADVISORY CRITERIA
BY THURSDAY INTO THE HOLIDAY WEEKEND. CONFIDENCE IN EXACT HEAT
VALUES REMAIN SOMEWHAT LIMITED DUE TO UNCERTAINTY IN AFTERNOON
DEWPOINTS POTENTIALLY MIXING OUT WITH NOTABLE SUBSIDENCE IN THE
VERTICAL COLUMN AS HEAT INDEX VALUES ARE HIGHLY SENSITIVE TO
DEWPOINT VALUES. WITH THE RIDGE IN PLACE, CONVECTIVE COVERAGE
WILL BE REDUCED AS MOST ACTIVITY BECOMES ISOLATED TO SCATTERED
AND STAYS MOSTLY CONFINED TO MOUNTAINS DURING EACH AFTERNOON AND
EVENING, WITH VERY ISOLATED INSTANCES OF CONVECTION EAST OF THE
MOUNTAINS. CURRENT GUIDANCE SUGGESTS THE SYNOPTIC PATTERN CAUSING
THE POTENTIAL PROLONGED HEAT COULD PERSIST THROUGH THE HOLIDAY
WEEKEND WITH LITTLE INDICATION OF SIGNIFICANT RELIEF. WHILE
HEAT INDEX FOR THE NEXT COUPLE OF DAYS IS FORECAST TO BE AT
LEAST SEVERAL DEGREES BELOW ADVISORY CRITERIA, VALUES OF AROUND
OR SLIGHTLY BELOW 105 ARE EXPECTED TO CREEP INTO ELBERT COUNTY,
GEORGIA THIS AFTERNOON. IN COLLABORATION WITH NWS FFC, ELBERT CO
WILL BE INCLUDED IN A HEAT ADVISORY. HEAT ADVISORIES ARE LIKELY
TO CONTINUE THROUGH THE WEEK, WHILE GRADUALLY EXPANDING IN COVERAGE.
THOSE WITH OUTDOOR PLANS, INCLUDING HOLIDAY AND RECREATION, SHOULD
PREPARE FOR SEVERAL DAYS OF ELEVATED HEAT RISK. STAY HYDRATED,
TAKE FREQUENT BREAKS IN AIR-CONDITIONED OR SHADED AREAS, AND NEVER
LEAVE CHILDREN OR PETS UNATTENDED IN VEHICLES.
AVIATION /12Z MONDAY THROUGH FRIDAY/
AT KCLT AND ELSEWHERE: MOSTLY VFR CONDITIONS EXPECTED THROUGH THE
FORECAST PERIOD OUTSIDE OF POTENTIAL MOUNTAIN VALLEY FOG/LOW STRATUS
THROUGH DAYBREAK. UPDATED KAVL TO INCLUDE AN MVFR CIG TEMPO MENTION
THROUGH 13Z, WHILE REMOVING ANY MENTION OF FOG/LOW STRATUS ELSEWHERE
AS CONFIDENCE IS TOO LOW FOR A TAF MENTION. WINDS ARE GENERALLY
LIGHT AND VARIABLE THROUGH DAYBREAK AND PICK UP OUT OF THE NORTHEAST
DURING THE DAYTIME PERIOD, WHILE KAVL MAINTAINS A NORTH TO
NORTHWESTERLY COMPONENT THROUGH THE PERIOD. GUIDANCE CONTINUES TO
DEVELOP SHOWERS AND THUNDERSTORMS OVER THE WESTERN HALF OF THE AREA,
WITH THE BEST CHANCE OF ANY SHOWER OR THUNDERSTORM MENTION WITH
ASSOCIATED RESTRICTIONS REMAINING OVER KAND AND KAVL. PLACED A
PROB30 FOR TSRA AT KAND AND A VCSH MENTION AT KAVL AS A RESULT.
LINGERING CONVECTIVE DEBRIS AND AFTERNOON CU WILL KEEP LOW VFR CIGS
IN PLACE DURING THE AFTERNOON, BUT SHOULD SCATTER BY THIS EVENING
INTO THE OVERNIGHT HOURS TONIGHT. ANOTHER ROUND OF MOUNTAIN VALLEY
FOG/LOW STRATUS IS POSSIBLE OVERNIGHT TONIGHT.
OUTLOOK: DIURNAL SHOWERS AND THUNDERSTORMS ARE EXPECTED MAINLY
ACROSS THE MOUNTAINS THROUGH THE WORKWEEK. MOUNTAIN VALLEY FOG/LOW
STRATUS WILL BE POSSIBLE EACH MORNING.
CLIMATE
RECORDS FOR 07-02
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAVL 93 1970 65 1943 70 2018 44 1988
1954
1931
KCLT 101 1931 64 1943 76 1991 56 2008
1970
1931
KGSP 101 1954 66 1943 77 1931 53 1899
RECORDS FOR 07-03
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAVL 93 1970 65 1988 70 2018 50 2008
1897 1931 1937
1932
KCLT 99 1931 70 1988 76 1925 56 2010
KGSP 99 2016 70 1988 77 1925 56 1984
1970
1953
RECORDS FOR 07-04
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAVL 97 1948 68 1976 70 2016 51 1986
KCLT 99 1993 70 1968 76 1993 55 1933
1955
KGSP 100 1993 70 1988 75 2018 58 2021
1996
1933
GSP WATCHES/WARNINGS/ADVISORIES
GA...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
GAZ029.
NC...NONE.
SC...NONE.
CAC
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