744
FXUS62 KCHS 281821
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
221 PM EDT THU MAY 28 2026
WHAT HAS CHANGED
ALL SECTIONS HAVE BEEN UPDATED. ADDED A KEY MESSAGE FOR COASTAL
FLOODING POTENTIAL.
KEY MESSAGES
- 1) HOT AND HUMID CONDITIONS WITH PERIODS OF SHOWERS AND
THUNDERSTORMS ACROSS SE GA/SC TODAY. LOCALLY HEAVY DOWNPOURS
ARE POSSIBLE.
- 2) LOCALIZED FLASH FLOODING IS POSSIBLE MAINLY ACROSS PORTIONS
OF SOUTHEAST GEORGIA FRIDAY, THEN ACROSS MUCH OF THE AREA
INCLUDING THE SOUTH CAROLINA LOWCOUNTRY SATURDAY.
- 3) HIGH TIDE COULD BRING MINOR INUNDATION OF VERY LOW LYING
AREAS ALONG THE SOUTHERN SOUTH CAROLINA COAST EARLY FRIDAY
EVENING.
DISCUSSION
KEY MESSAGE 1: HOT AND HUMID CONDITIONS WITH PERIODS OF SHOWERS AND
THUNDERSTORMS ACROSS SE GA/SC TODAY. LOCALLY HEAVY DOWNPOURS
ARE POSSIBLE.
A MID LEVEL TROUGH WILL EXTEND ACROSS THE MID-ATLANTIC STATES
TONIGHT, WHILE RIDGING GETS SUPPRESSED TO THE SOUTH. AT THE SURFACE,
A COLD FRONT WILL SINK INTO THE REGION, LIKELY SETTLING NEAR THE
SAVANNAH RIVER BY SUNRISE. ATMOSPHERE REMAINS QUITE MOIST WITH
PWATS NEAR OR JUST OVER 2 INCHES, WHICH IS ABOVE THE 95TH
PERCENTILE OF CLIMO.
RADAR EARLY THIS AFTERNOON HAS BECOME MORE ACTIVE, WITH INCREASING
COVERAGE OF SHOWERS AND THUNDERSTORMS. CONVECTION SHOULD LARGELY
REMAIN SUB-SEVERE, THOUGH THERE IS POTENTIAL FOR LOCALLY HEAVY
DOWNPOURS. 12Z HREF CONTINUES TO INDICATE A 10-30% CHANCE OF 3"/3 HR
WITH A 50-70% OF 1"/3 HR, HIGHEST OVER SOUTHEAST GEORGIA. A FLOOD
ADVISORY, OR PERHAPS EVEN A FLASH FLOOD WARNING, CANNOT BE RULED
OUT.
WITH THE FRONT IN THE VICINITY, SHOWERS COULD LINGER AT TIMES
THROUGHOUT THE NIGHT, POSSIBLY BECOMING MORE FOCUSED OVER SOUTHEAST
GEORGIA WITH TIME AS DRIER TRIES TO MOVE IN FROM THE NORTH.
KEY MESSAGE 2: LOCALIZED FLASH FLOODING IS POSSIBLE MAINLY ACROSS
PORTIONS OF SOUTHEAST GEORGIA FRIDAY, THEN ACROSS MUCH OF THE AREA,
INCLUDING THE SOUTH CAROLINA LOWCOUNTRY, SATURDAY.
ON FRIDAY, A COLD FRONT IS FORECAST TO SLOW AS IT PUSHES OVER THE
SAVANNAH RIVER, EXPECTED TO BECOME STATIONARY OVER SE GA FRIDAY
AFTERNOON. AT H5, A BROAD WEAKNESSES WILL DEVELOP OVER THE SOUTHEAST
U.S. DEEP MOISTURE CONVERGENCE WILL LIKELY DEVELOP ALONG THE NW TO
SE ORIENTED FRONT ACROSS SE GA AND HIGH RESOLUTION GUIDANCE
INDICATES THAT SHOWERS AND THUNDERSTORMS WILL RAPIDLY DEVELOP ACROSS
SE GA FROM LATE MORNING THROUGH THE AFTERNOON HOURS. PWATS SOUTH OF
THE FRONT APPROACH 2.25 IN, IN THE 98TH PERCENTILE WITH MODERATE
CAPE IN THE 1000-1500 J/KG RANGE. ADDITIONALLY, GIVEN THE
AFOREMENTIONED WEAKNESS ALOFT, STORM MOTIONS WILL BE VERY SLOW,
LIKELY AROUND 10 KT OR LESS, ESPECIALLY NEAR THE FRONT. THE GREATEST
HEAVY RAINFALL THREAT EXISTS SOUTH AND WEST OF SAVANNAH, WHERE PROBS
FOR GREATER THAN 1 INCH OF RAINFALL AT ANY GIVEN LOCATION ARE AROUND
20-30%. FURTHER NORTH, ESPECIALLY ACROSS THE SC LOWCOUNTRY, MOISTURE
CONTENT WILL BE MUCH MORE LIMITED AND RAINFALL COVERAGE WILL BE MUCH
LESS.
A RELATIVE LULL IN PRECIP IS EXPECTED THROUGH THE OVERNIGHT HOURS
FRIDAY NIGHT BEFORE COVERAGE AND INTENSITY INCREASES EARLY SATURDAY
MORNING AS A SHORTWAVE APPROACHES THE CWA. WITH THE BOUNDARY LIFTING
A BIT INTO EASTERN SC, THE PRIMARY MOISTURE BAND WILL BE MORE
EFFECTIVELY COVER THE AREA FROM THE CHARLESTON METRO TO THE SAVANNAH
METRO. WITH MODEST STORM MOTIONS PARALLEL TO THE FRONT, PWATS STILL
GREATER THAN THE 96TH PERCENTILE, AND THE INCREASED UPPER FORCING,
THERE SHOULD BE WIDESPREAD CONVECTIVE COVERAGE WITH SOME LOCATIONS
RECEIVING PROLONGED HEAVY RAINFALL. STILL A BIT FAR OUT IN TIME FOR
THE CONVECTIVE ALLOWING MODELS TO REALLY RESOLVE THE POTENTIAL
MAGNITUDE OF THE LOCALIZED PRECIP, BUT AT LEAST A LOCALIZED FLASH
FLOODING THREAT WILL EXIST IN PROXIMITY TO WHERE THE FRONT
EVENTUALLY SETS UP EARLY SATURDAY MORNING THROUGH THE AFTERNOON.
PRECIP COVERAGE WANES LATER SATURDAY IN THE WAKE OF THE WAVE ALOFT
AND THE SURFACE RIDGE BUILDS ACROSS THE AREA ON SUNDAY, RESULTING IN
WIDESPREAD ISENTROPIC LIFT THROUGH THE DAY, BUT EFFECTIVELY BRINGING
AN END TO THE FLOODING THREAT.
KEY MESSAGE 3: HIGH TIDE COULD BRING MINOR INUNDATION OF VERY LOW
LYING AREAS ALONG THE SOUTHERN SOUTH CAROLINA COAST EARLY FRIDAY
EVENING.
A PERIOD OF MODERATE TO BREEZY NORTHEAST WINDS FRIDAY IN COMBINATION
WITH THE APPROACHING FULL MOON AND APOGEE WILL BRING ELEVATED HIGH
TIDE LEVELS FRIDAY, POSSIBLY PERSISTING INTO SATURDAY. MINOR
INUNDATION OF VERY LOW LYING AREAS OF CHARLESTON AND COLLETON
COUNTIES IS POSSIBLE EARLY FRIDAY EVENING, WITH A LESSER THREAT
EARLY SATURDAY EVENING.
AVIATION /18Z THURSDAY THROUGH TUESDAY/
PREVAILING VFR IS EXPECTED THROUGH THE 18Z TAF CYCLE, HOWEVER THERE
COULD BE BRIEF RESTRICTIONS IN SHOWERS AND THUNDERSTORMS THIS
AFTERNOON INTO THIS EVENING. A COLD FRONT IS EXPECTED TO DROP INTO
THE AREA OVERNIGHT, WHICH COULD SPUR ADDITIONAL CONVECTION.
PROBABILITIES OF SIGNIFICANT DIRECT IMPACTS ARE TOO LOW SO KEPT
MENTION OUT OF THE TAF AT THIS TIME. AS SIMILAR TO PREVIOUS NIGHTS,
COULD NOT RULE OUT SOME PATCHY GROUND FOG OVERNIGHT.
SHOWER AND THUNDERSTORM COVERAGE IS EXPECTED TO INCREASE AGAIN AFTER
DAYBREAK FRIDAY, ESPECIALLY AT KSAV. USED A PROB30 TO ADDRESS
THIS POTENTIAL. AT KCHS/KJZI, LATEST GUIDANCE INDICATES THE
FRONT WOULD BE SOUTH OF THE TERMINALS WITH DRIER CONDITIONS
EXPECTED SO NO MENTION OF ADDITIONAL CONVECTION AT THIS TIME.
EXTENDED AVIATION OUTLOOK: MORE PERIODIC FLIGHT RESTRICTIONS ARE
POSSIBLE FRIDAY INTO THE WEEKEND AS THE POTENTIAL FOR WIDESPREAD
SHOWERS/THUNDERSTORMS INCREASES. IN ADDITION, PATCHY OVERNIGHT FOG
AND/OR STRATUS CANNOT BE RULED OUT AFTER RECENT RAINS.
MARINE
THROUGH TONIGHT: SOUTHWEST WINDS WILL PERSIST OVER THE COASTAL
WATERS THE REMAINDER OF THE DAY INTO THE EVENING WITH SPEEDS LESS
THAN 15 KNOTS. A COLD FRONT WILL DROP INTO THE REGION FROM THE NORTH
TONIGHT TOWARDS EARLY FRIDAY MORNING AND WITH WINDS TURNING TO THE
NORTHEAST IN ITS WAKE. SPEEDS WILL BEGIN TO INCREASE WITH SOME GUSTS
AROUND 20 KT OVER THE CHARLESTON COUNTY WATERS BY AROUND DAYBREAK.
SEAS WILL AVERAGE 2-3 FEET.
FRIDAY THROUGH MONDAY: BREEZY NE WINDS FRIDAY MORNING ALONG THE
SOUTH CAROLINA COAST WILL TREND MORE MODERATE THROUGH THE DAY, WHILE
SOUTH OF THE SAVANNAH RIVER, CLOSER TO THE QUASI-STATIONARY
BOUNDARY, WINDS WILL BE LIGHTER. ANOTHER PERIOD OF BREEZY NORTHEAST
WINDS ARRIVES IN THE WAKE OF A COLD FRONT PUSHING SOUTH SUNDAY
MORNING, WITH SCAS LIKELY NEEDED INTO SUNDAY NIGHT. SEAS ALSO PEAK
LATER SUNDAY AS WINDSWELL BUILDS SEAS TO 6-8 FT, GREATEST ACROSS THE
OFFSHORE SC WATERS. MARINE CONDITIONS IMPROVE EARLY NEXT WEEK.
RIP CURRENTS: AN ELEVATED RIP CURRENT RISK WILL REMAIN THROUGH
FRIDAY WITH A MODEST EASTERLY SWELL AROUND 3 TO 4 FEET EVERY 8
SECONDS AND SEA BREEZE INFLUENCES. A MODERATE RISK OF RIP
CURRENTS IS IN PLACE FOR ALL AREA BEACHES THROUGH FRIDAY.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
CEB/ETM
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