183
FXUS62 KCHS 250830
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
430 AM EDT WED JUN 25 2025
SYNOPSIS
HOT AND HUMID CONDITIONS ARE EXPECTED TO CONTINUE WITH RAIN
CHANCES INCREASING TODAY INTO LATE WEEK AS SURFACE TROUGHING
BEGINS TO FORM NEAR THE REGION AND A FEW UPPER DISTURBANCES
PASS THROUGH. A FEW THUNDERSTORMS MAY BECOME STRONG TO SEVERE
ON WEDNESDAY.
NEAR TERM /THROUGH TONIGHT/
TODAY: ALOFT, A LARGE/STRONG RIDGE WILL REMAIN CENTERED ACROSS
KY/TN, ENCOMPASSING MUCH OF THE MID-ATLANTIC AND SOUTHEAST, BUT
SHOULD BEGIN TO SHOW SOME SIGNS OF WEAKENING AND/OR NUDGING JUST
INLAND TO THE LOCAL AREA AS A BROAD MID-UPPER LVL LOW ACROSS THE
WESTERN ATLANTIC DRIFTS ACROSS FLORIDA AND SOUTHERN GEORGIA. MUCH
LIKE THE PREVIOUS FEW DAYS, WARM AND HUMID CONDITIONS WILL TRANSPIRE
ALONG THE WESTERN PERIPHERY OF THE ATLANTIC HIGH, WITH POCKETS OF
DRY AIR DEPICTED ON WATER VAPOR AND IN LOCAL MODEL SOUNDINGS
SUGGESTING A RATHER LIMITED SCENARIO FOR AFTERNOON CONVECTION TO
DEVELOP, AT LEAST INTO EARLY AFTERNOON HOURS. STRONG SFC HEATING
PRIOR TO ANY CONVECTION UNDER MOSTLY SUNNY/PARTLY CLOUDY SKIES ALONG
WITH 1000-850 MB THICKNESSES SUPPORT TEMPS TO WARM INTO THE MID-
UPPER 90S AGAIN THIS AFTERNOON, WARMEST AWAY FROM COASTAL AREAS.
SOME MIXING OUT OF SFC DEWPTS IS ALSO EXPECTED HEADING INTO
AFTERNOON HOURS, LIMITING THE DURATION OF MAX HEAT INDEX VALUES
ACROSS THE LOCAL AREA TODAY. STILL, MANY AREAS COULD EXPERIENCE HEAT
INDEX VALUES REACHING THE 104-107 RANGE THIS AFTERNOON, ESPECIALLY
IF SHOWERS/THUNDERSTORMS DO NOT OCCUR DURING PEAK HEATING HOURS.
THERE IS A LIMITED RISK FOR A FEW SPOTS TO TOUCH HEAT INDEX VALUES
UP TO 108-109 DEGREES EARLY AFTERNOON, BUT THE DURATION SHOULD BE
FAIRLY SHORT AND LIKELY OCCUR WITH MOISTURE POOLING ALONG AN
INLAND MOVING SEA BREEZE. FOR THIS REASON, A HEAT ADVISORY HAS
NOT BEEN ISSUED, BUT CONDITIONS WILL CONTINUE TO BE MONITORED
FOR THE NEED IN CASE THE SITUATION CHANGES.
A FEW SHOWERS AND/OR THUNDERSTORMS CAN NOT BE RULED OUT ALONG/AHEAD
OF THE SEA BREEZE THIS AFTERNOON, ESPECIALLY GIVEN THE APPROACH OF
THE MID-UPPER LVL LOW TO THE EAST-SOUTHEAST, AND GIVEN THE EXPECTANCY
OF HIGH INSTABILITY LOCALLY DUE TO STRONG SFC HEATING AND LOW-LVL
MOISTURE, AN ISOLATED STRONG AND/OR SEVERE THUNDERSTORM CAN NOT
BE RULED OUT, MAINLY PULSE LIKE IN NATURE AND CAPABLE OF PRODUCING
DAMAGING WINDS. HOWEVER, THE MORE NOTABLE SEVERE WEATHER CONCERN
IS LIKELY TO OCCUR DURING EVENING HOURS.
THIS EVENING: A BROAD MID-UPPER LVL LOW CENTERED OFF THE SOUTHEAST
COAST WILL SLOWLY NUDGE EASTWARD WITH TIME, FORCING THE LARGE-SCALE
RIDGE TO RETREAT FURTHER INLAND. VORT ENERGY WRAPPING AROUND THE
NORTH/NORTHWEST PERIPHERY OF THE LOW COULD PLAY A KEY ROLE IN THE
DEVELOPMENT OF SHOWERS/THUNDERSTORMS DEVELOPING ACROSS A BROAD
REGION OF SFC TROUGHING OVER THE CAROLINAS (STARTING ACROSS NORTH
CAROLINA), WITH A BULK OF GLOBAL AND HIRES MODELS SUGGESTING
ACTIVITY TO CONGEAL/BROADLY ORGANIZE INTO A CLUSTER WITHIN A MODESTLY
SHEARED ENVIRONMENT, THEN TRACKING SOUTH-SOUTHWEST, PRIMARILY
JUST INLAND TO THE LOCAL AREA NEAR THE ARRIVING SEA BREEZE. HOWEVER,
COLD POOLING COULD EASILY ALLOW ACTIVITY TO REACH INLAND COUNTIES
OF SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA IN A SEVERE
STATE, AND TO A LESSOR DEGREE COASTAL COUNTIES, MAINLY ACROSS SOUTHEAST
GEORGIA. LOCALLY, ENVIRONMENTAL CONDITIONS ARE RATHER IMPRESSIVE
ACROSS INLAND AREAS AHEAD OF THIS ACTIVITY, WITH SBCAPE AROUND
3500 J/KG, LOW-LVL LAPSE RATES AROUND 8.5 C/KM, DCAPE NEAR THE
1200-1400 J/KG RANGE AND INVERTED-V SOUNDINGS SUGGESTIVE OF
THUNDERSTORMS WITH DAMAGING WIND POTENTIAL SHOULD THEY OCCUR
LOCALLY. THERE IS EVEN SOME RISK FOR SMALL HAIL, BUT THIS WILL
BE SECONDARY CONCERN. THE PRIMARY TIME-FRAME FOR SEVERE WEATHER
REMAINS BETWEEN 6PM TO 12AM THIS EVENING.
AFTER MIDNIGHT: WEAK SHEAR AND LOSS OF DIURNAL HEATING WILL
EVENTUALLY TAKE A TOLL IN REGARDS TO COLD POOLING AND THUNDERSTORM
INTENSITY. HOWEVER, SHOWERS AND GENERAL THUNDERSTORMS REMAIN IN THE
FORECAST ACROSS SOUTHERN AREAS INTO LATE NIGHT. TEMPS WILL REMAIN
VERY MILD PRIOR TO SHOWER/THUNDERSTORM ACTIVITY, BUT SHOULD
EVENTUALLY DIP INTO THE LOWER 70S INLAND TO MID 70S NEAR THE BEACHES.
SHORT TERM /THURSDAY THROUGH SATURDAY/
THE UPPER-LVL RIDGE SITUATED OVER THE MID-ATLANTIC THAT HAS BEEN
SITTING ACROSS THE SOUTHEASTERN CONUS THE LAST COUPLE OF DAYS WILL
CONTINUE TO BREAK DOWN THROUGHOUT THURSDAY AND FRIDAY AS IT MOVES
OFFSHORE OVER THE WEEKEND. WITH THIS TRANSITION, EXPECT A MORE
TYPICAL SUMMERTIME PATTERN TO FINALLY SETUP FOR THE NEXT COUPLE OF
DAYS. REMNANT VORTICITY FROM AN MCS ON WEDNESDAY COMBINED WITH A
WEAK UPPER-LVL LOW MEANDERING ACROSS FLORIDA MIGHT YIELD THE CHANCE
FOR SHOWERS AND THUNDERSTORMS TO FORM IN THE AFTERNOONS ON THURSDAY
THROUGH SATURDAY. AT THE SURFACE, AN EXTENSIVE FIELD OF MOISTURE
WILL REMAIN OVER THE SOUTHEAST WITH PWAT VALUES RANGING FROM 1.50 TO
1.75 INCHES THROUGHOUT THE PERIOD. THIS WILL BE MORE THAN ENOUGH
MOISTURE TO SPARK UP SOME SHOWERS AND THUNDERSTORMS EACH AFTERNOON
AS THE SEA BREEZE PUSHES INLAND. IN ADDITION, SPC HAS MOST OF THE
REGION HIGHLIGHTED BY A LEVEL 1 OUT OF 5 RISK FOR SEVERE WEATHER ON
THURSDAY WITH THE PRIMARY CONCERN BEING LOCALLY DAMAGING WIND GUSTS.
OVERNIGHT LOWS WILL REMAIN MILD AND ONLY DIP INTO THE LOW TO MID 70S.
LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/
THIS WEAK UPPER-LVL LOW WILL CONTINUE TO MEANDER ACROSS FLORIDA
BEFORE EVENTUALLY DISSIPATING ON SUNDAY. A MORE ZONAL PATTERN WILL
SETUP OVER THE SOUTHEAST AND ENSEMBLES CONTINUE TO INDICATE DAILY
CHANCES OF RAIN THROUGH EARLY NEXT WEEK. TEMPERATURES WILL REMAIN
SLIGHTLY ABOVE NORMAL FOR THIS TIME OF THE YEAR.
AVIATION /07Z WEDNESDAY THROUGH SUNDAY/
VFR CONDITIONS WILL PREVAIL AT CHS/JZI/SAV TERMINALS THROUGH 06Z
THURSDAY. HOWEVER, THERE IS SOME RISK FOR AN AFTERNOON SHOWER OR
THUNDERSTORM IMPACTING THE TERMINALS WITH A SEA BREEZE SHIFTING
INLAND, FOLLOWED BY ANOTHER RISK FOR SHOWERS/THUNDERSTORMS
DURING EVENING HOURS. AT THIS TIME, PROBABILITIES REMAIN TOO LOW
TO INCLUDE MENTION OF SHRA/TSRA AT THE TERMINALS THIS AFTERNOON,
AND THE BULK OF CONVECTION DURING EVENING HOURS APPEARS TO REMAIN
INLAND TO THE TERMINALS. FUTURE TAF ISSUANCES COULD NEED TO
INCLUDE MENTION OF THIS ACTIVITY.
EXTENDED AVIATION OUTLOOK: VFR WILL MAINLY PREVAIL THROUGHOUT THE
PERIOD, HOWEVER BRIEF FLIGHT RESTRICTIONS ARE POSSIBLE WITHIN
SHOWERS AND THUNDERSTORMS THAT DEVELOP IN THE AFTERNOON AND/OR
EVENING.
MARINE
TODAY AND TONIGHT: ATLANTIC HIGH PRESSURE WILL PREVAIL FOR A BULK OF
THE DAY AND INTO TONIGHT, FAVORING CONDITIONS THAT REMAIN WELL BELOW
SMALL CRAFT ADVISORY LEVELS THROUGH TONIGHT. IN GENERAL, A SOUTHWEST
WIND WILL GRADUALLY TURN SOUTH MID-LATE MORNING, THEN PEAK IN THE 10-
15 KT RANGE AS A SEA BREEZE DEVELOPS AND PUSHES INLAND. A FEW
SHOWERS AND THUNDERSTORMS COULD ARRIVE TO COASTAL AREAS LATE EVENING
AND AFTER MIDNIGHT TONIGHT, PRODUCING HIGHER WIND GUSTS, SEAS AND
SOME RISK FOR SEVERE WEATHER ACROSS GEORGIA WATERS, BUT OUTSIDE THIS
ACTIVITY, WINDS ARE EXPECTED TO RETURN TO SOUTHWEST AND REMAIN
AROUND 10 KT OR LESS. SEAS WILL GENERALLY RANGE AROUND 2 FT.
THURSDAY THROUGH SUNDAY: AS A WEAK ESE SWELL CONTINUES TO MIX IN,
SEAS WILL REMAIN AROUND 1 TO 3 FT. EXPECT GENERALLY SOUTHERLY WINDS
AT 5 TO 10 KT TO PREVAIL THROUGHOUT THE PERIOD. IT COULD BECOME A
BIT GUSTY EACH AFTERNOON WITH GUSTS UP TO 15 TO 20 KT AS THE
SEABREEZE PUSHES INLAND (GUSTS STRONGEST ACROSS THE IMMEDIATE
COASTLINE AND THE CHARLESTON HARBOR). OTHERWISE, NO MARINE CONCERNS
EXPECTED.
RIP CURRENTS: A 1.5 FT, 7-8 SECOND SWELL WILL IMPACT THE BEACHES
ALONG WITH A 10-15 KT ONSHORE WIND TODAY. GIVEN THESE CONDITIONS ARE
SIMILAR TO YESTERDAY WITH SEVERAL RIP CURRENTS REPORTED ALONG TYBEE
ISLAND, GA, A MODERATE RISK FOR RIP CURRENTS IS IN PLACE ALONG
GEORGIA BEACHES THROUGH THIS EVENING.
TIDES/COASTAL FLOODING
ASTRONOMICAL TIDES WILL PEAK AROUND 6.5 FT MLLW AT CHARLESTON
WITH THIS EVENING'S HIGH TIDE CYCLE. LATE AFTERNOON WINDS WILL
ONLY BE MARGINALLY SUPPORTIVE OF INCREASING TIDAL DEPARTURES.
THIS EVENING'S HIGH TIDE WILL LIKELY PEAK AROUND 6.8-6.9 FT
MLLW, FALLING JUST SHORT OF COASTAL FLOOD ADVISORY CRITERIA.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
NEAR TERM...DPB
SHORT TERM...DENNIS
LONG TERM...DENNIS
AVIATION...DENNIS/DPB
MARINE...DENNIS/DPB
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