761
FXUS62 KCHS 311921
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
321 PM EDT SUN MAY 31 2026
WHAT HAS CHANGED
ALL SECTION HAVE BEEN UPDATED.
KEY MESSAGES
- 1) LOCALLY HEAVY RAINFALL AND ISOLATED FLASH FLOODING POSSIBLE
THROUGH THIS EVENING, ESPECIALLY ACROSS SOUTHEAST GEORGIA.
- 2) A LOW-END THREAT FOR LOCALIZED MINOR FLOODING CONTINUES
THROUGH TUESDAY AS A STALLED FRONT AND AN APPROACHING COLD
FRONT SUPPORT DAILY SHOWERS AND THUNDERSTORMS.
- 3) MINOR COASTAL FLOODING IS POSSIBLE ALONG THE CHARLESTON AND
COLLETON COUNTY COASTLINES THIS EVENING AND TUESDAY EVENING.
DISCUSSION
KEY MESSAGE 1: LOCALLY HEAVY RAINFALL AND ISOLATED FLASH
FLOODING POSSIBLE THROUGH THIS EVENING, ESPECIALLY ACROSS
SOUTHEAST GEORGIA.
THE MID-LEVELS CONTINUE TO FEATURE WEST TO NORTHWEST FLOW
OVERHEAD. AT THE SURFACE, HIGH PRESSURE OFF THE OUTER BANKS THIS
EVENING IS PUSH A COLD FRONT SOUTH OF OUR AREA. THE PROXIMITY
OF THE FRONT HAS KEPT DEEP MOISTURE OVER PORTIONS OF OUR AREA,
WITH PWATS PEAKING IN THE 2.0-2.2" RANGE. THE LATEST CAMS AND
VARIOUS ENSEMBLES STILL POINT TO AREAS SOUTH OF I-16 AS HAVING
THE HIGHEST PROBABILITIES FOR HEAVY RAINFALL AND FLOODING. THIS
REGION IS WHERE WPC HAS A SLIGHT RISK IN THEIR EXCESSIVE
RAINFALL OUTLOOK. THIS MAKES SENSE BECAUSE THE SETUP LOCALLY SUPPORTS
SLOW MOVING STORMS, WHICH COULD ALSO ANCHOR AND/OR BACKBUILD.
GIVEN THE EXCEEDINGLY ACTIVE AND WET CONDITIONS IN THIS AREA
OVER THE LAST WEEK OR SO, ISOLATED FLASH FLOODING REMAINS A
CONCERN.
KEY MESSAGE 2: A LOW-END THREAT FOR LOCALIZED MINOR FLOODING
CONTINUES THROUGH TUESDAY AS A STALLED FRONT AND AN APPROACHING COLD
FRONT SUPPORT DAILY SHOWERS AND THUNDERSTORMS.
A STALLED FRONT WILL LINGER ACROSS THE FORECAST AREA THROUGH MONDAY,
INTERACTING WITH A MOIST AIRMASS CHARACTERIZED BY PWAT VALUES OF 1.6-
1.9 INCHES. THIS WILL MAINTAIN AN UNSETTLED PATTERN WITH SCATTERED
TO NUMEROUS SHOWERS AND A FEW EMBEDDED THUNDERSTORMS. THE MEANDERING
FRONT DRAPED ALONG THE SC COAST AND SOUTHERN GEORGIA ALONG WITH A
WEAK AREA OF LOW PRESSURE DEVELOPING OFF THE SC COAST WILL FOCUS THE
GREATEST RAINFALL POTENTIAL ACROSS COASTAL AREAS OF SOUTHEAST SOUTH
CAROLINA. TUESDAY, AN APPROACHING COLD FRONT FROM THE NORTH WILL
SLOWLY DROP THROUGH THE AREA, PROVIDING CONTINUED SUPPORT FOR
SCATTERED CONVECTION. AS A RESULT, SHOWER AND THUNDERSTORM COVERAGE
SHOULD BEGIN TO DECREASE FROM NORTH TO SOUTH TUESDAY EVENING, WITH
THE GREATEST RAINFALL POTENTIAL SHIFTING TOWARD SOUTHEAST GEORGIA
AND AREAS ALONG AND SOUTH OF I-16 AHEAD OF THE FRONT.
ALTHOUGH CONVECTION WILL REMAIN SOMEWHAT DISORGANIZED, SLOW STORM
MOTIONS AND LOCALIZED TRAINING COULD RESULT IN POCKETS OF REPEATED
RAINFALL. GIVEN THE MODEST RAINFALL AMOUNTS, THE OVERALL FLOOD
THREAT REMAINS ON THE LOWER END. FOR MONDAY, THE LATEST NBM
INDICATES A 30-60% CHANCE OF EXCEEDING 1 INCH WITH THE GREATER
CHANCES OCCURRING ACROSS COASTAL SOUTH CAROLINA. ADDITIONALLY, THERE
IS A 15-30% CHANCE OF RAINFALL EXCEEDING 1 INCH ACROSS PORTIONS OF
THE AREA FOR TUESDAY. URBAN AND LOW-LYING AREAS, AND THOSE LOCATIONS
THAT RECEIVED 5+ INCHES OF RAIN OVER THE WEEKEND, MAY BE MORE
SUSCEPTIBLE TO MINOR FLOODING IF ADDITIONAL SHOWERS SET UP OVER THE
AREA.
KEY MESSAGE 3: MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
CHARLESTON AND COLLETON COUNTY COASTLINES THIS EVENING AND
TUESDAY EVENING.
GUSTY EAST-NORTHEASTERLY WINDS ARE CAUSING ELEVATED TIDAL
DEPARTURES FOR THIS EVENING'S HIGH TIDE (9:05 PM). THE TWL FORECAST
IS 7.0 FT MLLW, WHICH WOULD RESULT IN BRIEF, MINOR COASTAL
FLOODING IN THE USUAL FLOOD PRONE AREAS ACROSS CHARLESTON AND
COASTAL COLLETON COUNTIES. ALSO, IF SHOWERS AND THUNDERSTORMS
TRACK OVER THE REGION AROUND THE TIME OF HIGH TIDE, THEN
FLOODING COULD BE EXACERBATED. THEREFORE, THE ISSUANCE OF A
COASTAL FLOOD ADVISORY IS POSSIBLE FOR THIS EVENING.
ANOTHER SURGE OF NORTHEASTERLY WINDS COULD GENERATE MINOR
COASTAL FLOODING FOR THESE SAME LOCATIONS TUESDAY EVENING.
AVIATION /18Z SUNDAY THROUGH FRIDAY/
18Z TAFS:
KCHS AND KJZI: GUSTY NE WINDS ARE MAINTAINING MVFR CEILINGS.
RADAR IMAGERY INDICATES SOME SHOWERS NEARBY. HOWEVER, THE
PROBABILITIES OF DIRECT IMPACTS TO EITHER SITE ARE TOO LOW TO
MENTION IN EITHER TAF THIS AFTERNOON. THE HIGHER PROBABILITIES
OF DIRECT IMPACTS SHOULD OCCUR AFTER MIDNIGHT. THIS IS ALSO WHEN
CEILINGS ARE EXPECTED TO LOWER TO IFR. CONDITIONS SHOULD START
TO IMPROVE LATE IN THE TAF TIME PERIOD.
KSAV: GUSTY NE WINDS HAVE KEPT BKN CEILINGS IN THE MVFR TO VFR
CATEGORIES. RADAR IMAGERY INDICATES NUMEROUS SHOWERS WITH
ISOLATED THUNDERSTORMS NEAR THE AIRPORT. CAMS CONTINUE TO POINT
TO DIRECT IMPACTS TO THE AIRPORT, SO WE MAINTAINED THE TEMPO
GROUP FROM 18-22Z. THIS MAY NEED TO BE AMENDED BASED ON FUTURE
RADAR TRENDS. OTHERWISE, THIS ACTIVITY ALONG WITH THE WINDS WILL
TREND LOWER THIS EVENING. CEILINGS WILL ALSO LOWER, FIRST TO
MVFR AND THEN TO IFR OVERNIGHT. CONDITIONS SHOULD START
TO IMPROVE LATE IN THE TAF TIME PERIOD.
EXTENDED AVIATION OUTLOOK: PERIODIC FLIGHT RESTRICTIONS ARE
POSSIBLE THROUGH TUESDAY DUE TO SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS. PATCHY OVERNIGHT FOG AND/OR LOW STRATUS ARE ALSO
POSSIBLE.
MARINE
TONIGHT: GUSTY E WINDS FROM LATE THIS AFTERNOON WILL EASE THIS
EVENING AND OVERNIGHT, WITH SEAS TRENDING LOWER AS WELL. THE
SMALL CRAFT ADVISORY FOR THE CHARLESTON HARBOR HAS EXPIRED, AND
THE REMAINING ADVISORIES FOR THE SC WATERS WITHIN 20 NM ARE
SCHEDULED TO END THIS EVENING.
MONDAY THROUGH FRIDAY: TRANSIENT BENIGN MARINE CONDITIONS ON MONDAY
WILL BEGIN TO DETERIORATE TUESDAY MORNING. A WEAK AREA OF LOW
PRESSURE COULD DEVELOP OFFSHORE ON MONDAY BEFORE MOVING FARTHER INTO
THE ATLANTIC. MEANWHILE, STRENGTHENING HIGH PRESSURE TO THE NORTH
WILL CAUSE NORTHEASTERLY WINDS TO SURGE TUESDAY THROUGH WEDNESDAY
NIGHT. WINDS ARE EXPECTED TO RANGE FROM 20 TO 25 KT WITH GUSTS
AROUND 30 KT ACROSS THE WATERS. A BRIEF PERIOD OF GUSTS UP TO 35 KT
IS POSSIBLE WEDNESDAY MORNING ACROSS THE WATERS 20 TO 60 NM
OFFSHORE. SMALL CRAFT ADVISORY CONDITIONS APPEAR LIKELY, WITH A LOW-
END CHANCE FOR GALE CONDITIONS. STRONG EAST-NORTHEASTERLY SWELL WILL
ALSO BUILD INTO THE LOCAL WATERS TUESDAY EVENING, WITH SEAS PEAKING
WEDNESDAY AT 5 TO 7 FT IN THE NEARSHORE WATERS AND 7 TO 9 FT IN THE
OFFSHORE WATERS.
MARINE CONDITIONS ARE EXPECTED TO GRADUALLY IMPROVE WEDNESDAY NIGHT
INTO THURSDAY AS THE LOW MOVES FARTHER OUT INTO THE ATLANTIC. NO
ADDITIONAL MARINE CONCERNS ARE ANTICIPATED THROUGH THE REMAINDER OF
THE PERIOD.
RIP CURRENTS: THERE IS A MODERATE RISK FOR RIP CURRENTS AT ALL
OF OUR BEACHES THROUGH THIS EVENING.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR AMZ360-
362.
BRS
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