131
FXUS62 KCHS 241907
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
307 PM EDT FRI JUL 24 2026
WHAT HAS CHANGED
ALL SECTIONS HAVE BEEN UPDATED. FLASH FLOOD WATCH REMAINS IN
EFFECT.
KEY MESSAGES
- 1) A FLOOD WATCH IS IN EFFECT FOR THE CHARLESTON QUAD-COUNTY
IN THE SC LOWCOUNTRY. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE
TODAY AND AGAIN SATURDAY.
DISCUSSION
KEY MESSAGE 1: A FLOOD WATCH IS IN EFFECT FOR THE CHARLESTON
QUAD-COUNTY IN THE SC LOWCOUNTRY. LOCALLY HEAVY RAINFALL WILL
BE POSSIBLE TODAY AND AGAIN SATURDAY.
REST OF TODAY: A THREAT FOR LOCALLY HEAVY RAINFALL WILL REMAIN
POSSIBLE INTO THE EVENING HOURS TONIGHT. THIS IS EXPECTED AS THE
OBSERVED SEA-BREEZE CONTINUES TO PUSH INLAND, WITH A SLOW/STALLED
FRONT REMAINING IN/NEAR NORTHERN DORCHESTER/BERKELEY/COLLETON
COUNTIES IN SOUTH CAROLINA AND INTO CENTRAL GEORGIA THIS EVENING.
THE FIRST ROUND OF SHOWERS AND THUNDERSTORMS ARE ONGOING, AND ARE
EXPECTED TO EXPAND ACROSS THE REST OF SOUTH CAROLINA WITH LESSER
AREAL COVERAGE EXPECTED TO REACH DOWN INTO SOUTHEASTERN GEORGIA. AS
TEMPERATURES HAVE CLIMBED INTO THE LOWER TO UPPER 90S, INSTABILITY
VALUES HAVE RISEN INTO THE 1500-2000 J/KG RANGE, AND WHILE MOST OF
THE CAPE PROFILES ARE LONG AND SKINNY (GENERALLY A HEAVY RAIN
SIGNATURE), ISOLATED STRONGER WIND GUSTS IN THE 50-60 MPH RANGE
CANNOT BE RULED OUT.
THE MAIN THREAT CONTINUES TO BE HEAVY RAINFALL, GIVEN PWATS OF 2.0-
2.4" AND DEW POINTS IN THE LOWER TO UPPER 70S. IN ADDITION, SLOW
STORM MOTIONS ARE ANTICIPATED FROM CORFIDI VECTORS REMAINING IN THE
5-10 KNOT RANGE, LEADING TO LOCALLY HEAVY DOWNPOURS BEING POSSIBLE.
THUNDERSTORMS WILL BE CAPABLE OF PRODUCING A 1-3 INCHES PER HOUR,
WITH SCATTERED TOTAL RAINFALL AMOUNTS OF 1-3 INCHES. LOCATIONS THAT
SEE MULTIPLE ROUNDS OF RAINFALL MAY SEE 5+ INCHES, WHICH REMAINS
COVERED WELL BY THE EXISTING FLASH FLOOD WATCH ACROSS THE CHARLESTON
QUAD-COUNTY REGION. 12Z HREF GUIDANCE HAS COME IN A TOUCH LOWER FOR
BOTH 1"/3HR AND 3"/3HR PROBABILITIES COMPARED TO THE 00Z RUN, NOW
CARRYING A 70% CHANCE FOR AN INCH IN THREE HOURS, AND A 30% CHANCE
FOR 3 INCHES IN THREE HOURS, MOSTLY FOR PORTIONS OF SOUTHEAST SOUTH
CAROLINA THOUGH THE RISK DOES SPILL OVER INTO PORTIONS OF SOUTHEAST
GEORGIA. THE 12Z REFS IS LITTLE MORE AGGRESSIVE, KEEPING SCATTERED
50% CHANCES FOR 3"/6HR FOR BOTH SOUTHEAST SOUTH CAROLINA AND
SOUTHEAST GEORGIA THIS AFTERNOON/EVENING, SO BE ALERT TO THE
POSSIBILITY OF FLASH FLOODING EVEN IF YOU ARE OUTSIDE THE CURRENT
WATCH. THE MAIN TIMEFRAME FOR HEAVY DOWNPOURS TODAY IS FROM 3-9 PM.
SATURDAY: A MID-LEVEL TROUGH WILL BE OVER MOST OF THE EAST COAST,
WITH IT'S AXIS SHIFTING EASTWARD AS TIME PROGRESSES. ADDITIONALLY,
THERE WILL BE SEVERAL SUBTLE SHORTWAVES MOVING THROUGH THE BROADER
FLOW. AT THE SURFACE, THE STATIONARY FRONT WILL BE OVER THE
CHARLESTON TRI-COUNTY OR JUST NORTH OF THIS AREA. THERE WILL BE A
LARGE AREA OF VERY DEEP MOISTURE ACROSS THE SOUTHEAST U.S. PWATS
SHOULD PEAK IN THE 2.25-2.5" RANGE ACROSS OUR AREA. THIS WOULD BE
NEAR RECORD VALUES FOR CHS PER SPC SOUNDING CLIMATOLOGY AND 2-3
STANDARD DEVIATIONS ACCORDING TO NAEFS. THE COMBINATION OF LIFT FROM
THE FRONT ALONG WITH THE DEEP MOISTURE WILL GENERATE NUMEROUS TO
WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS OUR AREA. THEY'LL LIKELY
ONGOING EARLY IN THE MORNING, MAINLY NORTH OF I-26. BUT THE COVERAGE
AND INTENSITY WILL INCREASE INTO THE AFTERNOON, ESPECIALLY ALONG THE
SEABREEZE. THOUGH, BOTH THE DETERMINISTIC MODELS AND THE CAMS POINT
TOWARDS THE HIGHER QPF AMOUNTS BEING ALONG THE IMMEDIATE COAST.
RAINFALL PRODUCTIONS SHOULD BE VERY EFFICIENT AND WEAK STEERING
WINDS SHOULD CAUSE STORMS TO MOVE VERY SLOWLY AND/OR STAY IN PLACE.
IF HEAVY RAINFALL OCCURS OVER THE CHARLESTON AND/OR SAVANNAH METRO
AREAS, THEN FLASH FLOODING CONCERNS WOULD QUICKLY ESCALATE,
ESPECIALLY IF THERE ARE SATURATED SOILS FROM FRIDAY'S RAINFALL.
THEREFORE, WPC HAS MOST OF OUR SC COUNTIES UNDER A SLIGHT RISK FOR
EXCESSIVE RAINFALL. THE RAINFALL SHOULD GRADUALLY DECREASE IN BOTH
INTENSITY AND COVERAGE SATURDAY EVENING AND OVERNIGHT.
AVIATION /19Z FRIDAY THROUGH WEDNESDAY/
18Z TAFS - SCATTERED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED ACROSS
THE CHARLESTON QUAD-COUNTY AREA, WITH EXPANSION IN COVERAGE TO THE
SOUTH EXPECTED THROUGHOUT THE REST OF THE AFTERNOON HOURS. GIVEN THE
PREDICAMENT OF TIMING SCATTERED SHOWERS AND THUNDERSTORMS, HAVE
CONTINUED THE TEMPO GROUPS AT ALL TAF SITES. GIVEN MODEST
INSTABILITY WITH DEEP MOISTURE, CONDITIONS COULD QUICKLY BECOME
RESTRICTIVE AS TORRENTIAL DOWNPOURS WILL BE POSSIBLE. SHOWERS COULD
LINGER INTO THE OVERNIGHT HOURS, HOWEVER CONFIDENCE IS VERY LOW
REGARDING ANY POTENTIAL IMPACTS AT THE TERMINALS.
EXTENDED AVIATION OUTLOOK: A STATIONARY FRONT NEARBY WILL CONTINUE
TO BRING PERIODS OF FLIGHT RESTRICTIONS THROUGH SUNDAY DUE TO
SHOWERS AND THUNDERSTORMS.
MARINE
REST OF TODAY: SEMI-BREEZY SOUTHEASTERLY WINDS WITH GUSTS TO
NEAR 15 KNOTS WILL CONTINUE THIS AFTERNOON, WITH CHANCES FOR
SCATTERED SHOWERS AND THUNDERSTORMS PRIMARILY ALONG THE COAST.
EXPECT WINDS TO VEER AS THEY WEAKEN INTO SATURDAY MORNING.
EXTENDED MARINE: A STATIONARY FRONT NEARBY WILL BRING
SOUTHWESTERLY WINDS ON SATURDAY. WINDS WILL BRIEFLY VEER TO THE
NORTH AND NORTHEAST ON SUNDAY, THEN AGAIN MONDAY MORNING,
FOLLOWED BY A SHIFT TO THE SOUTHEAST MONDAY AFTERNOON. WINDS
WILL BECOME ELEVATED TUESDAY NIGHT INTO WEDNESDAY, SO SMALL
CRAFT ADVISORIES MAY BE NEEDED FOR PORTIONS OF OUR WATERS.
RIP CURRENTS: THERE IS A MODERATE RISK FOR RIP CURRENTS FOR ALL
LOCAL BEACHES TODAY (FRIDAY) DUE TO LONGER PERIOD SWELL AROUND 8
SECONDS AND ENHANCED SOUTHWESTERLY WIND GUSTS.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR SCZ043>045-149-150-
152.
MARINE...NONE.
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