211
FXUS62 KCHS 110711
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
311 AM EDT SAT JUL 11 2026
WHAT HAS CHANGED
ALL SECTIONS HAVE BEEN UPDATED.
KEY MESSAGES
- 1) HOT AND HUMID CONDITIONS WILL CONTINUE TODAY, WITH ISOLATED
TO SCATTERED THUNDERSTORMS THIS AFTERNOON/EVENING, A FEW
WHICH COULD BECOME STRONG TO SEVERE WITH DAMAGING WIND GUSTS
BEING THE PRIMARY THREAT.
- 2) RAIN CHANCES AND THUNDERSTORM COVERAGE EXPECTED TO INCREASE
SUNDAY THROUGH TUESDAY, BRINGING COOLER TEMPERATURES FOR A FEW
DAYS BEFORE TEMPERATURES RISE AGAIN MID-WEEK.
- 3) COASTAL FLOODING IS POSSIBLE WITH THE EVENING HIGH TIDE
FROM SUNDAY THROUGH WEDNESDAY.
DISCUSSION
KEY MESSAGE 1: HOT AND HUMID CONDITIONS WILL CONTINUE TODAY,
WITH ISOLATED TO SCATTERED THUNDERSTORMS THIS AFTERNOON/EVENING,
A FEW WHICH COULD BECOME STRONG TO SEVERE WITH DAMAGING WIND
GUSTS BEING THE PRIMARY THREAT.
ANOTHER HOT DAY IS EXPECTED WITH THE LOCAL AREA SITUATED UNDER
RIDGING ALOFT AND BETWEEN SFC HIGH PRESSURE EXTENDING ACROSS THE
WESTERN ATLANTIC AND LEE TROUGHING ACROSS THE MIDLANDS AND UPSTATE
REGION. A WESTERLY FLOW WILL HELP MIX OUT SFC DEWPTS LATE MORNING
AND AFTERNOON, POTENTIALLY INTO THE MID-UPPER 60S AWAY FROM COASTAL
AREAS, AND LOWEST WEST OF I-95 ACROSS SOUTHEAST GEORGIA. ONCE A SEA
BREEZE BEGINS TO SHIFT INLAND, DEWPTS WILL SURGE WITHIN THE MARINE
LAYER DURING PEAK HEATING HOURS, LIKELY LEADING TO HEAT INDEX VALUES
UP TO 108-110 DEGREES ALONG THE COASTAL CORRIDOR. GIVEN THE SETUP,
ALONG WITH A POTENTIAL DELAY IN SHOWER/THUNDERSTORM ACTIVITY UNTIL
LATE DAY/EARLY EVENING, A HEAT ADVISORY WILL REMAIN IN EFFECT FOR
COASTAL AREAS FROM 11 AM TO 7 PM TODAY.
REGARDING THUNDERSTORMS, COVERAGE AND ENVIRONMENT REMAINS SIMILAR TO
CONDITIONS EXPERIENCED THE PREVIOUS DAY WITH MODERATE INSTABILITY,
AMPLE DCAPE AND STRONG LOW-LVL LAPSE RATES SUPPORTIVE OF A FEW
STRONG TO SEVERE THUNDERSTORMS CAPABLE OF DAMAGING WIND GUSTS.
CONVECTION COULD START EARLY AFTERNOON, MAINLY ACROSS THE TRI-COUNTY
AREA NEAR A PINNED SEA BREEZE CLOSER TO THE COAST. SHOULD THIS
ACTIVITY DEVELOP, CONVECTIVE OUTFLOWS COULD CONTINUE TO PRODUCE
ADDITIONAL SHOWER/THUNDERSTORM ACTIVITY WITH HEAVY DOWNPOURS AS
PWATS REMAIN AROUND 2.0 INCHES. QUITE A BIT OF GUIDANCE SUGGESTS
ADDITIONAL SHOWERS/THUNDERSTORMS DEVELOPING UPSTREAM OF THE LOCAL
AREA WHILE H5 SHORTWAVE ENERGY TRAVERSES ACROSS THE INLAND TROUGH,
SOME OF WHICH COULD MAKE A RUN TOWARD INLAND LOCATIONS OF SOUTHEAST
SOUTH CAROLINA LATE DAY/EARLY EVENING. THE OVERALL STRENGTH OF THIS
CONVECTION APPEARS DEPENDENT ON THE TIME OF ARRIVAL, WITH A
WEAKENING TREND POSSIBLE IF DELAYED UNTIL SUNSET AND/OR SHORTLY
THEREAFTER. REGARDLESS, THE POTENTIAL FOR A FEW STRONG AND/OR SEVERE
THUNDERSTORMS COULD PERSIST INTO EARLY EVENING HOURS BEFORE
CONVECTION WANES IN A WEAKLY SHEARED ENVIRONMENT.
KEY MESSAGE 2: RAIN CHANCES AND THUNDERSTORM COVERAGE EXPECTED TO
INCREASE SUNDAY THROUGH TUESDAY, BRINGING COOLER TEMPERATURES FOR A
FEW DAYS BEFORE TEMPERATURES RISE AGAIN MID-WEEK.
SUNDAY: WEAK H500 TROUGHING TO OUR NORTH WILL BRING A WEAK SURFACE
LOW PRESSURE OFF THE VIRGINA/NORTH CAROLINA COAST AND INTO THE
ATLANTIC. A WEAK COLD FRONT ASSOCIATED WITH THE SURFACE LOW WILL
SLOWLY SAG DOWN INTO THE REGION, BRINGING INCREASED CHANCES FOR
SHOWERS AND THUNDERSTORMS TO THE REGION AS THE EXPECTED SEA-BREEZE
WILL PROVIDE ADDITIONAL LIFT FOR THUNDERSTORM DEVELOPMENT. WHILE
AGREEMENT AMONGST THE MODELS COULD BE HIGHER, A FEW MODELS CONTINUE
TO DEPICT A WEAK SURFACE LOW PRESSURE DEVELOPING ALONG THE COLD
FRONT, MOVING ACROSS THE AREA SUNDAY NIGHT BEFORE PUSHING OFFSHORE
ON MONDAY. WITH PRECIPITABLE WATER VALUES NEAR 2 INCHES AND SLOW
STORM MOTIONS EXPECTED, LOCALLY HEAVY RAINFALL WILL BE POSSIBLE. IF
A SURFACE LOW PRESSURE DOES DEVELOP, THAT WOULD FURTHER INCREASE
MOISTURE POOLING CAPABILITIES, WITH A MARGINAL RISK (LEVEL 1 OUT OF
4) FOR EXCESSIVE RAINFALL FROM WPC COVERING THAT THREAT.
BEFORE STORMS START FORMING IN THE AFTERNOON, THE HEAT WAVE
CONTINUES WITH AFTERNOON HIGHS IN THE MID TO UPPER 90S. DEWPOINTS
WILL BE HIGHEST ALONG THE COAST IN THE UPPER 70S, RESULTING IN HEAT
INDEX VALUES PEAKING NEAR 110 DEGREES RESULTING IN THE POSSIBILITY
FOR ANOTHER HEAT ADVISORY BEING NEEDED FOR SUNDAY. INLAND AREAS WILL
SEE A TOUCH LESS MOISTURE WITH DEWPOINTS IN THE LOWER 70S, KEEPING
HEAT INDEX IN THE LOWER TO MID 100S. AS FOR THE POTENTIAL FOR STRONG
TO SEVERE THUNDERSTORMS, 1500-2000 J/KG OF CAPE WILL CONTINUE
ISOLATED CHANCES, THOUGH SHEAR REMAINS LOW KEEPING CHANCES FOR
ORGANIZED CONVECTION LOW. WITH ASTRONOMICAL HIGH TIDE OF 6.44 FT
MLLW OCCURRING SHORTLY AFTER 7 PM, ANY THUNDERSTORM ACTIVITY NEAR
THE CHARLESTON PENINSULA WILL INCREASE CHANCES FOR IMPACTFUL COASTAL
FLOODING.
MONDAY - TUESDAY: COOLER AIR CONTINUES TO FILTER DOWN INTO THE
REGION AS A SURFACE HIGH PRESSURE MOVES TOWARDS/ACROSS THE
APPALACHIANS, WITH THE FRONT REMAINING ACROSS/SOUTH OF THE REGION
WHICH WILL CONTINUE PERIODIC CHANCES FOR RAINFALL ON MONDAY AND
TUESDAY. AS BEFORE, MODELS CONTINUE TO SUGGEST ANOTHER WEAK SURFACE
LOW PRESSURE MAY DEVELOP ALONG/NORTH OF THE FRONT. PRECIPITABLE
WATER VALUES CONTINUE TO REMAIN HIGH IN THE 2-2.5 INCH RANGE,
KEEPING THE THREAT FOR LOCALLY HEAVY RAINFALL ON THE ELEVATED SIDE,
WHICH WPC AGREES WITH AS THEY HAVE A MARGINAL RISK (LEVEL 1 OUT OF
4) FOR EXCESSIVE RAINFALL ON BOTH DAYS. SIMILAR TO SUNDAY, IF HEAVY
RAINFALL WERE TO OCCUR DURING EVENING HIGH TIDE, THIS WOULD INCREASE
IMPACTS FROM ANY COASTAL FLOODING AS ASTRO TIDES PEAK AT 6.57 FT
MLLW ON BOTH DAYS. THE INCREASED CLOUD COVERAGE FROM RAINFALL
CHANCES WILL BRING TEMPERATURES DOWN INTO THE UPPER 80S TO LOWER 90S
BOTH MONDAY AND TUESDAY..
H500 HEIGHTS BEGIN TO RISE AGAIN ON WEDNESDAY AS THE RIDGE
STRENGTHENS, WITH TEMPERATURES RISING BACK UP INTO THE LOWER TO MID
90S. TEMPERATURES LOOK TO FURTHER CLIMB INTO THE MID 90S THURSDAY
AND FRIDAY.
KEY MESSAGE 3: COASTAL FLOODING IS POSSIBLE WITH THE EVENING
HIGH TIDE FROM SUNDAY THROUGH WEDNESDAY.
ASTRONOMICAL INFLUENCES ON TIDES WILL INCREASE EARLY NEXT WEEK,
WITH A LUNAR PERIGEE ON MONDAY AND A NEW MOON ON TUESDAY. MINOR
COASTAL FLOODING IS POSSIBLE ACROSS CHARLESTON AND COASTAL
COLLETON COUNTIES SUNDAY EVENING. COASTAL FLOODING MAY INCREASE
MONDAY THROUGH WEDNESDAY WITH RISING ASTRO TIDES AND ONSHORE
WINDS. IN ADDITION, RAINFALL MAY OVERLAP WITH THE EVENING HIGH
TIDE CYCLES, SEE KEY MESSAGE 2 FOR ADDITIONAL DETAILS.
AVIATION /07Z SATURDAY THROUGH WEDNESDAY/
VFR CONDITIONS SHOULD PREVAIL AT CHS/JZI/SAV TERMINALS THROUGH 06Z
SUNDAY. HOWEVER, SHOWERS AND THUNDERSTORMS COULD IMPACT CHS/JZI
TERMINALS LATE AFTERNOON INTO EARLY EVENING HOURS. PROB30 GROUPS
REMAIN AT THESE TERMINALS FOR MVFR CONDITIONS ASSOCIATED WITH
THUNDERSTORMS BETWEEN 21-24Z TODAY. OUTSIDE CONVECTION, GUSTY
WEST/SOUTHWEST WINDS UPWARDS TO 15-20 KT ARE POSSIBLE DURING
AFTERNOON HOURS AT ALL TERMINALS.
EXTENDED AVIATION OUTLOOK: SHOWER AND THUNDERSTORM COVERAGE, ALONG
WITH RISKS OF ASSOCIATED RESTRICTIONS, MAY INCREASE SUNDAY THROUGH
TUESDAY.
MARINE
TODAY THROUGH TONIGHT: ANOTHER ROUND OF ENHANCED SOUTHWEST FLOW IS
ANTICIPATED DURING AFTERNOON/EVENING HOURS, WITH GUSTS TYPICALLY IN
THE 15-20 KT RANGE AND PERHAPS A FEW GUSTS UP TO 25 KT, HIGHEST NEAR
THE LAND/SEA INTERFACE WHERE A SEA BREEZE DEVELOPS THEN SHIFTS
INLAND. CONDITIONS COULD BECOME MARGINALLY SUPPORTIVE OF A SMALL
CRAFT ADVISORY IN THE CHARLESTON COUNTY WATERS AND POSSIBLY THE
CHARLESTON HARBOR, BUT ARE CURRENTLY FORECAST TO FALL JUST SHORT OF
CRITERIA. SEAS SHOULD RANGE BETWEEN 2-4 FT. THUNDERSTORMS ARE
EXPECTED TO DEVELOP INLAND THIS AFTERNOON AND EVENING, AND COULD
EVENTUALLY SHIFT ACROSS LOCAL WATERS WITH FREQUENT LIGHTNING AND
GUSTY WINDS. SPECIAL MARINE WARNINGS COULD EVENTUALLY BE NEEDED.
SUNDAY THROUGH WEDNESDAY: A WEAK COLD FRONT TO OUR NORTH WILL SLOWLY
SAG ACROSS THE REGION SUNDAY INTO MONDAY, CAUSING WINDS TO BECOME
NOTABLY WEAKER. WHILE WINDS LOOK TO START OUT WESTERLY SUNDAY,
SHOULD SEE DIRECTION GRADUALLY TURN MORE NORTH/NORTHEASTERLY BY
EARLY MONDAY MORNING. THIS TREND IS EXPECTED TO CONTINUE FOR MUCH OF
THE UPCOMING WEEK, WITH SEAS GENERALLY RANGING FROM 2 TO 3 FT.
RIP CURRENTS: A MODERATE RISK FOR RIP CURRENTS WILL REMAIN ALONG THE
SC/GA COAST TODAY. CONDITIONS WILL FEATURE 2-3 FT SWELL WITH WAVE
PERIODS UP TO 9 SECONDS. IN ADDITION, SSW WINDS WILL LIKELY GENERATE
A MODERATE LONGSHORE CURRENT, POSSIBLY SUPPORTING RIP CURRENTS NEAR
PIERS AND JETTIES.
CLIMATE
RECORD HIGH TEMPERATURES:
JULY 11:
KCHS: 102/1986
KCXM: 100/2001
KSAV: 103/1980
RECORD HIGH MINIMUM TEMPERATURES:
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 GAZ217>219-239-241.
SC...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM EDT THIS EVENING
FOR SCZ045-148>152.
MARINE...NONE.
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