770
FXUS62 KCHS 042320
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
720 PM EDT TUE AUG 4 2026
WHAT HAS CHANGED
AVIATION SECTION UPDATED FOR THE 0Z TAFS.
KEY MESSAGES
- 1) SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL IMPACT
THE REGION INTO THIS EVENING. LOCALLY HEAVY RAINFALL IS
POSSIBLE ALONG WITH A RISK FOR AN ISOLATED STRONG TO SEVERE
THUNDERSTORM.
- 2) A TYPICAL SUMMERTIME PATTERN RETURNS THROUGH THE WEEKEND,
WITH ISOLATED STRONG TO SEVERE THUNDERSTORMS POSSIBLE EACH
DAY.
DISCUSSION
KEY MESSAGE 1: SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS
WILL IMPACT THE REGION INTO THIS EVENING. LOCALLY HEAVY RAINFALL
IS POSSIBLE ALONG WITH A RISK FOR AN ISOLATED STRONG TO SEVERE
THUNDERSTORM.
THE MID-LEVELS CONSIST OF A CUT-OFF LOW OVER THE SOUTHEAST U.S.
IT'LL GRADUALLY SHIFT NORTH INTO THE OVERNIGHT. AT THE SURFACE,
A STATIONARY FRONT IS LOCATED TO OUR WEST AND NORTHWEST, AND
IT'S EXPECTED TO DISSIPATE AROUND DAYBREAK WEDNESDAY. PWATS
ACROSS OUR AREA ARE LOWER COMPARED TO THE PAST FEW DAYS. THOUGH,
THEY REMAIN AROUND 2", DEPENDING ON THE TIME PERIOD AND
LOCATION. TEMPERATURES IN THE UPPER 80S TO LOWER 90S ARE
GENERATING DECENT INSTABILITY. SPC MESOSCALE ANALYSIS SHOWS
MLCAPES IN THE 1,500-2,000 J/KG RANGE, WITH DCAPES AROUND 1,000
J/KG IN SOME LOCATIONS. EFFECTIVE BULK SHEAR IS 25-30 KT. THIS
HAS GENERATED CONVECTION ACROSS PORTIONS OF OUR INLAND
LOCATIONS THIS AFTERNOON. CAMS GENERALLY HAVE IT INCREASING IN
COVERAGE AND INTENSITY ALONG AND WEST OF THE I-95 CORRIDOR LATE
THIS AFTERNOON INTO THIS EVENING, AIDED PARTLY BY THE SEA
BREEZE. THERE IS A RISK FOR AN ISOLATED STRONG TO SEVERE
THUNDERSTORM THROUGH EARLY THIS EVENING, WITH DAMAGING WINDS
BEING THE PRIMARY THREAT. LOCALLY HEAVY RAINFALL IS ALSO
POSSIBLE INTO THIS EVENING. CONVECTION SHOULD THEN SHIFT MOSTLY
OFFSHORE LATE THIS EVENING AND OVERNIGHT, WITH A BAND REMAINING
POINTED TOWARDS CHARLESTON COUNTY AND VICINITY.
KEY MESSAGE 2: A TYPICAL SUMMERTIME PATTERN RETURNS THROUGH THE
WEEKEND, WITH ISOLATED STRONG TO SEVERE THUNDERSTORMS POSSIBLE
EACH DAY.
AS THE ATLANTIC RIDGE STRENGTHENS OFFSHORE OF THE EASTERN
SEABOARD, YIELDING SOUTH-SOUTHWESTERLY FLOW ACROSS THE
SOUTHEAST. THIS PERSISTENT PLUME OF MOISTURE WILL MAINTAIN PWAT
VALUES ~2 INCHES, WITH THE HIGHEST MOISTURE GENERALLY LOCATED
ALONG AND EAST OF THE I- 95 CORRIDOR. THIS PATTERN WILL SUPPORT
A TYPICAL SUMMERTIME PATTERN WITH THE AFTERNOON SEA BREEZE AND
REMNANT OUTFLOW BOUNDARIES SERVING AS THE MAIN FOCUS FOR
AFTERNOON/EVENING CONVECTION.
HIGH PWAT VALUES COMBINED WITH DEEP WARM-CLOUD LAYERS WILL
SUPPORT VERY EFFICIENT RAINFALL PRODUCTION, WITH RATES OF 1-2
INCHES PER HOUR POSSIBLE BENEATH THE STRONGEST THUNDERSTORMS.
ADDITIONALLY, THESE SHOWERS AND THUNDERSTORMS WILL BE MOVING ON
THE SLOWER SIDE (STORM MOTIONS OF ~10KT), MEANING LOCALIZED
FLOODING WILL LIKELY BE THE MAIN THREAT FOR EACH
AFTERNOON/EVENING (ESP. IN LOW-LYING AND/OR POOR DRAINAGE
AREAS). WHILE INSTABILITY REMAINS QUITE LIMITED ON WEDNESDAY,
POCKETS OF 1500-2000 J/KG OF SBCAPE STILL APPEAR POSSIBLE WHERE
SUFFICIENT HEATING OCCURS. AND THEN, THURSDAY THROUGH SATURDAY,
INSTABILITY WILL BE ABLE TO BUILD A BIT MORE IN THE
AFTERNOONS/EVENINGS THAN WEDNESDAY YIELDING A BETTER CHANCE FOR
A SEVERE RISK. ALSO, FORECAST SOUNDINGS INDICATE DCAPE VALUES OF
800- 1000 J/KG EACH AFTERNOON/EVENING AS WELL, WHICH COULD
SUPPORT A FEW STORMS CAPABLE OF PRODUCING DAMAGING WIND GUSTS.
THUS, AN ISOLATED SEVERE THUNDERSTORM CANNOT BE RULED OUT
COMPLETELY FOR EACH AFTERNOON/EVENING AS DAMAGING WIND GUSTS AND
CLOUD-TO-GROUND LIGHTNING COULD BE POSSIBLE WITHIN A STRONGER
CELL.
AVIATION /00Z WEDNESDAY THROUGH SUNDAY/
PRIOR TO THE 0Z TAFS, KCLX DETECTED A CLUSTER OF SHOWERS AND
THUNDERSTORMS ACROSS EXTREME SE GA. THESE CELLS MAY DRIFT INTO
THE SOUTHERN PORTION OF THE KSAV TERMINAL THIS EVENING,
HIGHLIGHTED WITH A TEMPO FROM 0-3Z. MUCH LIKE LAST NIGHT, SOME
DEGREE OF SHOWERS AND THUNDERSTORMS MAY DEVELOP OFF THE
CHARLESTON COUNTY LATE TONIGHT. ROUNDS OF SHOWERS MAY PUSH
ONSHORE, EXPECTED TO DRIFT ACROSS KJZI AND NEARING KCHS BY 6Z.
THE GREATEST COVERAGE OF SHOWERS MAY OCCUR BETWEEN 9-13Z,
HIGHLIGHTED WITH A TEMPO. SHOWERS SHOULD DIMINISH AFTER BY MID-
MORNING. HOWEVER, SEA BREEZE THUNDERSTORMS MAY DEVELOP NEAR KSAV
BETWEEN 18-22Z, HIGHLIGHTED WITH A TEMPO.
EXTENDED AVIATION OUTLOOK: PERIODIC FLIGHT RESTRICTIONS ARE
EXPECTED IN SHOWERS AND THUNDERSTORMS THIS WEEK.
MARINE
THROUGH TONIGHT: S WINDS AROUND 15 KT THIS EVENING WILL
TRANSITION TO THE SSW OVERNIGHT, EASING TO 10-15 KT BY DAYBREAK
WEDNESDAY. SEAS SHOULD BE IN THE 3-4 FT RANGE.
WEDNESDAY THROUGH SATURDAY: AS HIGH PRESSURE SITUATES ITSELF
ACROSS THE ATLANTIC, A TYPICAL SUMMERTIME PATTERN WILL TAKE
SHAPE FOR THE LOCAL WATERS THROUGH THE PERIOD. EXPECT INCREASED
WINDS ALONG THE LAND/SEA INTERFACE AS THE AFTERNOON SEABREEZE
KICKS INLAND EACH DAY. EAST-SOUTHEASTERLY SWELL WILL CONTINUE
THROUGH THE WEEKEND WITH SEAS RANGING FROM 2 TO 4 FT.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
NED
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