744
FXUS62 KCHS 080057
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
857 PM EDT TUE JUL 7 2026
WHAT HAS CHANGED
KEY MESSAGES HAVE BEEN UPDATED TO REMOVE HEAT/HUMIDITY AND
STRONG TO SEVERE THUNDERSTORMS THIS EVENING. THE AVIATION
SECTION HAS BEEN UPDATED FOR THE 00Z TAF ISSUANCE. THE MARINE
SECTION HAS BEEN UPDATED TO REFLECT ONGOING CONDITIONS.
KEY MESSAGES
- 1) HOT AND HUMID CONDITIONS WILL PERSIST THROUGH MUCH OF THE
WEEK.
- 2) TYPICAL SUMMERTIME AFTERNOON AND EVENING THUNDERSTORMS
THIS WEEK.
DISCUSSION
KEY MESSAGE 1: HOT AND HUMID CONDITIONS WILL PERSIST THROUGH
MUCH OF THE WEEK.
THE HEAT AND HUMIDITY WILL BUILD WEDNESDAY AS RIDGING ALOFT
STRENGTHENS. 850 HPA TEMPERATURE ARE FORECAST TO WARM TO 20-22C WITH
LOW-THICKNESSES PEAKING 1437-1440 METERS. THESE VALUES TYPICALLY
SUPPORT HIGHS WITHIN A 1-2 DEGREES EITHER SIDE OF 100 DEGREES.
DEWPOINTS ARE EXPECTED TO MIX OUT SOMEWHAT (LOWER-MID 70S) DURING
THE AFTERNOON, BUT DEWPOINT POOLING (UPPER 70S/LOWER 80S)
NEAR/BEHIND THE SEA BREEZE SHOULD PUSH HEAT INDICES TO DANGEROUS
LEVELS ACROSS PARTS OF THE COASTAL CORRIDOR WITH MAX HEAT INDICES
PEAKING IN THE 112-116 DEGREE RANGE FOR SEVERAL HOURS. FARTHER
INLAND, HEAT INDICES SHOULD GENERALLY PEAK 105-110 RANGE. GIVEN THE
ABOVE NOTED TRENDS, AN EXCESSIVE HEAT WATCH HAS BEEN POSTED FOR THE
COASTAL CORRIDOR, INCLUDING BOTH THE CHARLESTON AND SAVANNAH METRO
AREAS, WITH A HEAT ADVISORY FOR MUCH OF INTERIOR SOUTHEAST GEORGIA
INTO SOUTHEAST SOUTH CAROLINA. ONLY THE AREA FROM JENKINS COUNTY TO
HAMPTON COUNTY LOOK TO FALL SHORT OF THE 108 HEAT INDEX CRITERIA FOR
A HEAT ADVISORY. WARMING TEMPERATURES ALOFT WILL HELP LIMIT
AFTERNOON CONVECTION WITH ONLY ISOLATED COVERAGE EXPECTED. THERE ARE
SOME CAMS THAT SUPPORT A BIT MORE COVERAGE SO THIS WILL NEED TO BE
WATCHED AS SOME AREAS COULD FALL SHORT OF WARNING/ADVISORY CRITERIA
IF CONVECTION BECOMES MORE SCATTERED.
HEAT IS EXPECTED TO CONTINUE THROUGH THE END OF THE WEEK WITH
HEAT INDICES LIKELY AROUND THE 105 TO 110 RANGE AND HIGHS IN THE
MID TO UPPER 90S AREA WIDE. HEAT PRODUCTS LOOK TO CONTINUE AT
LEAST THROUGH THURSDAY AND POSSIBLY INTO FRIDAY WITH THE HIGHEST
PROBABILITY OF REACHING ADVISORY CRITERIA MAINLY EAST OF I-95
AND CLOSER TO THE COAST INCLUDING THE CHARLESTON AND SAVANNAH
METRO AREAS. WHILE HEAT INDICES MAY NOT BE AS HIGH AS EARLY
WEEK, THE BIGGER ISSUE WILL BE LONG DURATION HEAT STRESS MAINLY
ALONG THE COASTAL AREAS WHERE HEAT INDICES MIGHT NOT DROP TO
BELOW 100 DEGREES UNTIL WELL INTO THE EVENING AND OVERNIGHT
HOURS WITH LOWS IN THE UPPER 70S TO LOW 80S. SEVERAL DAYS OF
INTENSE HEAT AND MINIMAL COOLING OVERNIGHT HAS BEEN REFLECTED IN
THE HEATRISK PRODUCT WITH WIDESPREAD MAJOR (LEVEL 3 OF 4) AND A
CORRIDOR OF EXTREME (LEVEL 4 OF 4) ALONG THE IMMEDIATE COAST
THURSDAY AND FRIDAY. REGARDLESS OF ANY HEAT PRODUCTS THIS WILL
CONTINUE TO BRING A RISK OF HEAT-RELATED IMPACTS, ESPECIALLY TO
THOSE MORE VULNERABLE TO HEAT OR THOSE WITHOUT ADEQUATE
COOLING/HYDRATION.
KEY MESSAGE 1: TYPICAL SUMMERTIME AFTERNOON AND EVENING THUNDERSTORMS
THIS WEEK.
THE REGION WILL BE SITUATED BETWEEN HIGH PRESSURE OFFSHORE AND A
TROUGH OF LOW PRESSURE INLAND THROUGH MUCH OF THE WEEK, WITH RIDGING
THE PRIMARY FEATURE ALOFT. LARGER SCALE FORCING IS LACKING, BUT
ISOLATED TO PERHAPS SCATTERED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE EACH DAY LARGELY DUE TO DAYTIME HEATING AND MESOSCALE
BOUNDARIES LIKE THE SEA BREEZE. COVERAGE WILL BE HIGHEST IN THE
AFTERNOON AND EARLY EVENINGS, BEFORE DWINDLING AFTER SUNSET WITH
LOSS OF INSOLATION. WHILE THE ENVIRONMENT FAVORS MAINLY PULSE-TYPE
CONVECTION, A COUPLE STRONG TO SEVERE STORMS WITH DAMAGING WIND
GUSTS CANNOT BE RULED OUT. LOCALLY HEAVY RAINFALL IS ALSO POSSIBLE
WITH ANY STORMS, BUT FLOODING RISK IS LOW ESPECIALLY GIVEN THE HOT
AND DRY CONDITIONS OF LATE.
RAIN CHANCES WILL LIKELY INCREASE SUNDAY INTO MONDAY AS A MORE
POTENT SHORTWAVE TROUGH MOVES ACROSS THE MID-ATLANTIC. EXPECT
STORM COVERAGE TO INCREASE SUNDAY AFTERNOON COMPARED TO THE
NORMAL SUMMERTIME PATTERN. STORMS WILL LIKELY BE FOCUSED ALONG A
SAGGING FRONT THAT WILL SLOWLY DRIFT SOUTH WITH TIME. GIVEN THE
INCREASED COVERAGE AND MAYBE A LITTLE MORE DEEP LAYER FLOW, A
COUPLE STRONG TO SEVERE STORMS WITH DAMAGING WINDS MAY BE
POSSIBLE ON SUNDAY.
AVIATION /00Z WEDNESDAY THROUGH SUNDAY/
VFR CONDITIONS ARE EXPECTED TO PREVAIL AT CHS/JZI/SAV TERMINALS
THROUGH 00Z THURSDAY. HOWEVER, AN ISOLATED SHOWER/THUNDERSTORM
COULD IMPACT ANY TERMINAL WEDNESDAY AFTERNOON. TIMING AND
CONFIDENCE REMAIN TOO LOW TO MENTION SHOWERS/THUNDERSTORMS IN
THE LATEST TAF ISSUANCE.
EXTENDED AVIATION OUTLOOK: THERE WILL BE A RISK FOR TSTM IMPACTS AT
THE TERMINALS EACH AFTERNOON/EVENING, ESPECIALLY AT KCHS AND
KSAV.
MARINE
THROUGH TONIGHT: THE PRESSURE PATTERN SHOULD SUPPORT SOUTH-SOUTHWEST
WINDS BETWEEN 15 TO 20 KTS, WITH A FEW GUSTS UP TO 25 KT NEAR
THE COAST THIS EVENING. GIVEN THE LIMITED DURATION AND SPATIAL
COVERAGE OF STRONGER GUSTS, HAVE OPTED TO KEEP LOCAL WATERS OUT
OF SMALL CRAFT ADVISORIES. SEAS SHOULD RANGE BETWEEN 2-4 FT, BUT
SLOWLY SUBSIDE ABOUT A FOOT LATE TONIGHT.
WEDNESDAY: A SOUTHERLY FLOW REGIME WILL PREVAIL WITH SOME SEA BREEZE
ENHANCEMENTS LIKELY ALONG THE LAND/SEA INTERFACE AND CHARLESTON
HARBOR WHERE GUSTS NEAR 20 KT WILL BE POSSIBLE. A TYPICAL SUMMER
TIME NOCTURNAL SURGE WILL IMPACT THE AREA WEDNESDAY NIGHT WITH SOUTH
TO SOUTHWEST WINDS 15-20 KT. GUSTS COULD NEAR 25 KT AT TIMES, BUT
DURATIONS DO NOT QUITE LOOK FREQUENT ENOUGH FOR A SMALL CRAFT
ADVISORY AT THIS TIME.
CLIMATE
RECORD HIGH TEMPERATURES:
JULY 8:
KCHS: 100/2016
KSAV: 101/2010
JULY 10:
KCHS: 100/1986
KCXM: 99/1986
JULY 11:
KCXM: 100/2001
JULY 12:
KCXM: 97/1966
RECORD HIGH MINIMUM TEMPERATURES:
JULY 7:
KCHS: 80/2017
KCXM: 82/2022
KSAV: 80/1883
JULY 8:
KCHS: 82/2016
KCXM: 83/2016
KSAV: 80/1990
JULY 9:
KCHS: 80/1998
KCXM: 85/1998
KSAV: 80/1883
JULY 10:
KCHS: 81/1986
KCXM: 82/1986
JULY 11:
KCHS: 80/2016
KCXM: 82/2016
JULY 12:
KCHS: 79/2020
KCXM: 82/1998
CHS WATCHES/WARNINGS/ADVISORIES
GA...HEAT ADVISORY FROM 11 AM TO 7 PM EDT WEDNESDAY FOR GAZ099>101-
114-115-137-216-238-240.
EXTREME HEAT WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
EVENING FOR GAZ217>219-239-241.
SC...HEAT ADVISORY FROM 11 AM TO 7 PM EDT WEDNESDAY FOR SCZ043-044-
147.
EXTREME HEAT WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
EVENING FOR SCZ045-148>152.
MARINE...NONE.
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