710
FXUS62 KCHS 080638
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
238 AM EDT WED JUL 8 2026
WHAT HAS CHANGED
ALL SECTIONS HAVE BEEN UPDATED.
KEY MESSAGES
- 1) A PROLONGED HEAT WAVE WILL MAINTAIN HOT AND HUMID CONDITIONS
FOR THE MAJORITY OF THE WEEK.
- 2) TYPICAL SUMMERTIME AFTERNOON AND EVENING THUNDERSTORMS THIS
WEEK.
DISCUSSION
KEY MESSAGE 1: A PROLONGED HEAT WAVE WILL MAINTAIN HOT AND HUMID
CONDITIONS FOR THE MAJORITY OF THE WEEK.
THE CENTER OF A H5 595 DAM RIDGE WILL REMAIN OVER MIDDLE FL THIS
AFTERNOON, WITH A RIDGE EXTENDING NORTHWARD ACROSS THE SOUTHEAST
U.S. TODAY. THE RIDGING WILL PROVIDE THE REGION WITH VERY WARM LLVL
THICKNESSES. AN AREA OF BROAD LOW PRESSURE IS FORECAST TO REMAIN
OVER THE CENTRAL CAROLINAS THIS AFTERNOON, SUPPORTING SW WINDS
ACROSS SE GA AND SC. DUE TO THE SW WINDS, THE SEA BREEZE MAY BEGIN
AN HOUR OR TWO LATER THIS AFTERNOON COMPARED TO EARLIER THIS WEEK.
GIVEN THE WARM LLVL THICKNESSES, SLOWER SEA BREEZE, AND DECENT
INSOLATION, HIGH TEMPERATURES IN THE UPPER 90S WILL BE COMMON THIS
AFTERNOON, SOME LOCATIONS MAY PEAK AT 100 DEGREES. HOWEVER, 90TH
PERCENTILE GUIDANCE INDICATES THAT KCHS WILL LIKELY CONTINUE THE
2ND LONGEST STREAK OF CONSECUTIVE DAYS WITH TEMPERATURES <100
DEGREES ON RECORD, 2595 DAYS. THE RECORD NUMBER OF DAYS IN 5784
WHICH ENDED 6/18/1970. THE HOT TEMPERATURES COMBINED WITH DEWPOINTS
IN THE MID TO UPPER 70S SHOULD YIELD HEAT INDEX VALUES GREATER THAN
108 DEGREES FOR MOST OF THE FORECAST AREA. COASTAL COUNTIES OF SC/GA
ARE FORECAST TO SEE HEAT INDEX VALUES TO PEAK BETWEEN 110 TO 115
DEGREES. THE DANGEROUS HEAT INDEX VALUES WILL BE HIGHLIGHTED WITH AN
EXTREME HEAT WARNING, ELSEWHERE A HEAT ADVISORY WILL BE IN EFFECT
FROM 11 AM TO 7 PM. LATE AFTERNOON THUNDERSTORMS MAY PROVIDE SOME
POCKETS OF RELIEF FROM THE HEAT.
THE HEAT WAVE 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 THIS AFTERNOON, 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 2: TYPICAL SUMMERTIME AFTERNOON AND EVENING THUNDERSTORMS
THIS WEEK.
HOT AND HUMID CONDITIONS SHOULD YIELD MODERATE INSTABILITY ACROSS
THE COASTAL COUNTIES ONCE THE SEA BREEZE DEVELOPS AND PUSHES INLAND
THIS AFTERNOON INTO EARLY THIS EVENING. RECENT RUNS OF THE HRRR AND
RRFS INDICATED VERY LITTLE THUNDERSTORM COVERAGE THIS AFTERNOON, DUE
TO DEWPOINT MIXING WELL INTO THE 60S WEST OF THE SEA BREEZE.
HOWEVER, HREF DOES INDICATE ISOLATED TO SCATTERED THUNDERSTORMS NEAR
THE SEA BREEZE THIS AFTERNOON. THE FORECAST WILL FEATURE SCHC TO CHC
POPS ACROSS THE COASTAL COUNTIES DURING THE LATE AFTERNOON AND
EVENING. THIS PATTERN IS EXPECTED TO CONTINUE FOR THURSDAY THROUGH
SATURDAY, WITH ISOLATED COVERAGE ON THURSDAY AND FRIDAY.
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 /06Z WEDNESDAY THROUGH SUNDAY/
6Z TAFS: TERMINALS WILL REMAIN VFR WITH LIGHT SOUTHWEST WINDS THIS
MORNING. ISOLATED TO SCATTERED THUNDERSTORMS ARE FORECAST TO DEVELOP
NEAR THE SEA BREEZE THIS AFTERNOON, EXPECTED TO DEVELOP NEAR OR OVER
THE TERMINALS BETWEEN 20-24Z, HIGHLIGHTED WITH PROB30. IN THE WAKE
OF THE SEA BREEZE, WINDS WILL SHIFT FROM THE SOUTH-SOUTHWEST WITH
GUSTS NEAR 20 KTS, ESPECIALLY AT KJZI. CONVECTION AND WIND
GUSTS SHOULD DISSIPATED EARLY THIS EVENING.
EXTENDED AVIATION OUTLOOK: THERE WILL BE A RISK FOR TSTM IMPACTS AT
THE TERMINALS EACH AFTERNOON/EVENING, ESPECIALLY AT KCHS AND
KSAV.
MARINE
TODAY THROUGH TONIGHT: THE PRESSURE PATTERN SHOULD SUPPORT SOUTH-
SOUTHWEST WINDS BETWEEN 10 TO 15 KTS, WITH OCCASIONAL GUSTS INTO
THE LOW 20 KTS. WAVE HEIGHTS ARE FORECAST TO FAVOR 3 TO 4 FT.
THURSDAY AND FRIDAY: SURGES IN THE WAKE OF THE SEA BREEZE MAY RESULT
IN SOUTHWEST WINDS TO INCREASE EACH AFTERNOON AND EVENING ON
THURSDAY AND FRIDAY. WIND GUSTS MAY PEAK AROUND 25 KTS, POSSIBLY
REQUIRING SMALL CRAFT ADVISORIES. THE SHORT DURATION OF THE ELEVATED
WINDS SHOULD KEEP WAVE HEIGHTS BETWEEN 3 TO 4 FT.
THIS WEEKEND INTO MONDAY: THE PRESSURE PATTERN SHOULD SUPPORT SOUTH-
SOUTHWEST WINDS BETWEEN 10 TO 15 KTS, WITH OCCASIONAL GUSTS INTO THE
LOW 20 KTS. WAVE HEIGHTS ARE FORECAST TO FAVOR 3 TO 4 FT.
CLIMATE
RECORD HIGH TEMPERATURES:
JULY 8:
KCHS: 100/2016
KSAV: 101/2010
JULY 9:
KCXM: 99/1986
JULY 10:
KCHS: 100/1986
KCXM: 99/1986
KSAV: 102/1879
JULY 11:
KCXM: 100/2001
JULY 12:
KCXM: 97/1966
RECORD HIGH MINIMUM TEMPERATURES:
JULY 8:
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
CHS WATCHES/WARNINGS/ADVISORIES
GA...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM EDT THIS EVENING
FOR GAZ099>101-114-115-137-216-238-240.
EXTREME HEAT WARNING FROM 11 AM THIS MORNING TO 7 PM EDT THIS
EVENING FOR GAZ217>219-239-241.
SC...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM EDT THIS EVENING
FOR SCZ043-044-147.
EXTREME HEAT WARNING FROM 11 AM THIS MORNING TO 7 PM EDT THIS
EVENING FOR SCZ045-148>152.
MARINE...NONE.
NED
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