824
FXUS62 KCHS 061132
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
732 AM EDT THU AUG 6 2026
WHAT HAS CHANGED
KEY MESSAGE 1 AND THE AVIATION SECTION WAS UPDATED.
KEY MESSAGES
- 1) ANOTHER ROUND OF EARLY MORNING SHOWERS AND THUNDERSTORMS
WILL IMPACT PORTIONS OF THE COAST WITH A RISK FOR HEAVY
RAINFALL AND LOCALIZED FLOODING CONCENTRATING AROUND THE
CHARLESTON METRO AREA DURING THE MORNING COMMUTE.
- 2) A TYPICAL SUMMERTIME PATTERN WILL REMAIN IN PLACE THROUGH
THE UPCOMING WEEKEND. ISOLATED STRONG TO SEVERE THUNDERSTORMS
AND THE THREAT FOR LOCALIZED HEAVY RAINFALL WILL BE POSSIBLE
EACH DAY.
DISCUSSION
KEY MESSAGE 1: ANOTHER ROUND OF EARLY MORNING SHOWERS AND
THUNDERSTORMS WILL IMPACT PORTIONS OF THE COAST WITH A RISK FOR
HEAVY RAINFALL AND LOCALIZED FLOODING CONCENTRATING AROUND THE
CHARLESTON METRO AREA DURING THE MORNING COMMUTE.
CONVECTION HAS BEEN SLOW TO FORM THIS MORNING AND WHAT HAS
DEVELOPED HAS STRUGGLED DESPITE FAVORABLE INSTABILITY OVER THE
ATLANTIC. NEAR TERM GUIDANCE STILL SUGGESTS CONVECTION COULD
SPREAD INTO PARTS OF THE CHARLESTON TRI-COUNTY OVER THE COMING
HOURS; HOWEVER, GIVEN TRENDS, THE FORECAST WAS UPDATED TO LOWER
POPS INTO THE CHANCE CATEGORY.
THE SYNOPTIC PATTERN REMAINS FAVORABLE FOR ANOTHER ROUND OF
NOCTURNAL SHOWERS/TSTMS TO DEVELOP OVER THE ATLANTIC OVER THE
NEXT FEW HOURS AND STREAM INLAND ALONG PARTS OF THE COAST.
SIMILAR TO WEDNESDAY MORNING, THE MEAN STEERING FLOW LOOKS TO
FAVOR THE BULK OF THE CONVECTION IMPACTING PARTS OF THE
CHARLESTON TRI-COUNTY, INCLUDING DOWNTOWN CHARLESTON. GOES-E
TOTAL PRECIPITABLE WATER DATA SHOW PWATS ARE ABOVE 2" AND THE
LATEST RAP OUTPUT SUGGEST PWATS WILL REMAIN IN THE 2-2.25"
RANGE ALONG THE COASTAL CORRIDOR. WHILE THESE VALUES ARE ~0.25"
LOWER THAN 24 HOURS, THERE IS STILL PLENTY OF DEEP MOISTURE AND
SUFFICIENT INSTABILITY (MLCAPE >1500 J/KG) NUDGING INLAND FROM
OFF THE ATLANTIC TO ALLOW ANY CONVECTION TO BE HIGHLY EFFICIENT
RAIN PRODUCERS CAPABLE OF PRODUCING A QUICK 1-2" IN A VERY SHORT
PERIOD OF TIME. HREF NEIGHBORHOOD PROBABILITIES FOR >1"/3HRS
ARE HIGHEST ACROSS CHARLESTON COUNTY, RUNNING 50-60% AND AROUND
10% FOR >3"/3HRS. WHILE FLASH FLOODING SEEMS UNLIKELY WITH THE
BULK OF THE HEAVIEST RAINFALL FALLING WITHIN 2 HOURS EITHER SIDE
OF LOW TIDE (807 AM IN CHARLESTON HARBOR), MINOR FLOODING OF
URBAN AREAS AROUND THE CHARLESTON METRO AREA AS WELL AS LOW-
LYING AND POOR DRAINAGE AREAS IN MORE RURAL SPOTS CAN NOT BE
RULED OUT. OF COURSE, DOWNTOWN CHARLESTON WILL BE MONITORED
CLOSELY AS ANY SUSTAINED PERIOD OF HEAVY RAINFALL THAT BECOMES
ALIGNED ACROSS THE PENINSULA COULD RESULT IN SOME SIGNIFICANT
ISSUES, EVEN AT LOW TIDE.
CONVECTION SHOULD SLOWLY WANE BY LATE MORNING, WITH A RISK FOR
SCATTERED SHOWERS/TSTMS REFOCUSING ALONG/WEST OF THE I-95
CORRIDOR AHEAD OF THE SEA BREEZE. HIGHS WILL WARM INTO THE
LOWER-MID 90S WITH HEAT INDICES PEAKING 100-105. SIMILAR TO THE
PAST SEVERAL NIGHTS, CONVECTION IS EXPECTED TO REDEVELOP OVER
THE ATLANTIC LATE TONIGHT AS LOW-LEVEL CONVERGENCE SHIFTS BACK
ALONG THE WEST WALL OF THE GULF STREAM AFTER MIDNIGHT. ACTIVITY
DOES NOT LOOK AS EXTENSIVE AS THE PAST FEW NIGHTS, BUT SOME
DEGREE OF ISOLATED TO PERHAPS SCATTERED SHOWERS/TSTMS WILL MAKE
A RUN FOR THE COAST DURING THE EARLY MORNING HOURS FRIDAY.
KEY MESSAGE 2: A TYPICAL SUMMERTIME PATTERN WILL REMAIN IN
PLACE THROUGH THE UPCOMING WEEKEND. ISOLATED STRONG TO SEVERE
THUNDERSTORMS AND THE THREAT FOR LOCALIZED HEAVY RAINFALL WILL
BE POSSIBLE EACH DAY.
THE PATTERN WILL BE DOMINATED BY DEEP HIGH PRESSURE OVER THE
WESTERN ATLANTIC AND EASTERN SEABOARD. THIS WILL SUPPORT DAILY
SCATTERED CONVECTION THROUGH THE WEEKEND, WITH THE SEA BREEZE
AND ANY REMNANT OUTFLOW BOUNDARIES SERVING AS THE PRIMARY FOCUS
FOR AFTERNOON AND EVENING SHOWER AND THUNDERSTORM DEVELOPMENT.
PERSISTENT SOUTHERLY FLOW WILL CONTINUE TO ADVECT DEEP MOISTURE
INTO THE REGION. MODERATE INSTABILITY LOOKS TO DEVELOP EACH
AFTERNOON, WITH SBCAPE VALUES RISING TO 2500-3000 J/KG. PWAT
VALUES NEAR OR SLIGHTLY ABOVE 2 INCHES NEARLY EACH DAY WILL
SUPPORT EFFICIENT RAINFALL RATES, WITH SOME STORMS CAPABLE OF
DROPPING A QUICK 1-2 INCHES OF RAIN IN A SHORT PERIOD. IN
ADDITION, SLOW STORM MOTIONS OF AROUND 10 KT, COMBINED WITH
TRAINING OR REPEATED ROUNDS OF CONVECTION, COULD INCREASE THE
POTENTIAL FOR ISOLATED INSTANCES OF MINOR FLOODING, ESPECIALLY
IN LOW-LYING AND POOR DRAINAGE AREAS. FRIDAY WILL BE THE
EXCEPTION, AS SOMEWHAT DRIER AIR FILTERS IN NOTED BY POCKETS OF
PWATS BETWEEN 1.5 TO 1.7 INCHES. THIS SHOULD LIMIT CONVECTION
COVERAGE AS WELL AS THE MINOR FLOODING THREAT. LASTLY, WITH
LITTLE SHEAR IN THE ENVIRONMENT, STORMS WILL REMAIN PULSE-LIKE.
ALTHOUGH WIDESPREAD SEVERE WEATHER IS NOT EXPECTED, A FEW
STRONGER TO MARGINALLY SEVERE STORMS COULD PRODUCE DAMAGING WIND
GUSTS.
AVIATION /12Z THURSDAY THROUGH MONDAY/
06/12Z TAFS:
KCHS/KJZI: CONVECTION HAS BEEN SLOW TO DEVELOP THIS MORNING.
NEAR TERM GUIDANCE IS STILL INSISTENT SHOWERS/TSTMS WILL FORM
SOON AND SPREAD INTO PARTS OF THE CHARLESTON METRO. OPTED TO
PULL BACK ON THE TSRA FORECAST SLIGHTLY GIVEN CURRENT TRENDS.
PROB30 FOR TSRA WAS HIGHLIGHTED AT KJZI 12-15Z WITH VCSH AT
KCHS. LAST MINUTE RADAR TRENDS AT PRESS TIME MAY NECESSITATE A
CHANGE. CONVECTION SHOULD CONSOLIDATE WEST OF THE CHARLESTON
TERMINALS BY EARLY AFTERNOON AND REMAIN THERE. OVERNIGHT,
GUIDANCE SUGGESTS ANOTHER ROUND OF SHOWERS/TSTMS WILL DEVELOP
OFFSHORE WHICH COULD SPREAD INTO KCHS/KJZI. GIVEN TRENDS THIS
MORNING, NO MENTION OF SHRA/TSRA WILL BE INCLUDED FOR THE 12Z
TAF CYCLE.
KSAV: MORNING CONVECTION SHOULD LARGELY REMAIN EAST OF THE
TERMINAL THROUGH DAYBREAK. ISOLATED TO SCATTERED CONVECTION IS
EXPECTED TO START TO FOCUS NEAR I-95 BY LATE MORNING THEN
CONSOLIDATE FARTHER INLAND LATER IN THE AFTERNOON. PROB30 FOR
TSRA WAS INCLUDED 16-19Z TO ACCOUNT FOR ACTIVITY DEVELOPING
NEAR THE TERMINAL BY LATE MORNING.
EXTENDED AVIATION OUTLOOK: PERIODIC FLIGHT RESTRICTIONS ARE
EXPECTED IN SHOWERS AND THUNDERSTORMS THIS WEEK AND INTO THIS
WEEKEND.
MARINE
THROUGH TONIGHT: ANOTHER ROUND OF SHOWERS/TSTMS IS EXPECTED TO
IMPACT THE WATERS THIS MORNING. THESE STORMS WILL BE CAPABLE OF
PRODUCING GUSTY WINDS, CLOUD-TO-GROUND LIGHTNING AND HEAVY
RAINFALL REDUCING VSBYS TO 1 NM OR LESS. OUTSIDE OF CONVECTION,
SOUTH TO SOUTHEAST WINDS 10 KT OR LESS WILL PERSIST INTO TONIGHT
WITH SEAS 1-3 FT.
FRIDAY THROUGH TUESDAY: ATLANTIC HIGH PRESSURE WILL BE THE
DOMINANT SYNOPTIC FEATURE THROUGH THE WEEKEND. THIS WILL
GENERATE A TYPICAL SUMMERTIME WIND FIELD WITH INCREASED WINDS
ALONG THE LAND/SEA INTERFACE EACH AFTERNOON ASSOCIATED WITH THE
SEA BREEZE. MARINE CONDITIONS ARE EXPECTED TO REMAIN BELOW SMALL
CRAFT ADVISORY CRITERIA THROUGH THE PERIOD.
WATERSPOUTS: FORECAST SOUNDING OUTPUT AND ELEVATED NON-
SUPERCELL TORNADO PARAMETERS VALUES OVER THE NEARSHORE AND
OFFSHORE WATERS LOOK TO SUPPORT AN ELEVATED RISK FOR WATERSPOUTS
AGAIN THIS MORNING. SEVERAL WERE OBSERVED YESTERDAY. A MARINE
WEATHER STATEMENT TO ALERT MARINERS TO THIS POSSIBILITY WILL BE
ISSUED.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
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