101
FXUS62 KCHS 301803
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
203 PM EDT WED JUL 30 2025
SYNOPSIS
ATLANTIC HIGH PRESSURE PREVAILS OFFSHORE THROUGH THE REST OF
THE WORK WEEK, A TROUGH OF LOW PRESSURE WILL CONTINUE TO PRESS
INLAND. A COLD FRONT MAY STALL NEARBY THIS WEEKEND AND PROMOTE
HEAVY TO EXCESSIVE RAINFALL ACROSS THE REGION.
NEAR TERM /THROUGH TONIGHT/
INSTABILITY IS SLOWLY BUILDING OVER THE AREA THIS AFTERNOON.
ISOLATED TO SCATTERED CONVECTION CONTINUES TO PERCOLATE ACROSS
PARTS OF THE CHARLESTON TRI-COUNTY ALONG SEVERAL MESOSCALE
BOUNDARIES, BUT COVERAGE SHOULD SLOWLY RAMP UP AND REFOCUS
INLAND AS THE AFTERNOON PROGRESSES. NBM POPS AROUND 70% ACROSS
THE INTERIOR MAY BE A BIT HIGH BASED ON SOME OF THE LATEST CAMS,
BUT THESE WERE MOSTLY MAINTAINED AS IT DOES NOT REALLY IMPACT
OUR LOCAL MESSAGING THAT THE TSTM MAIN RISKS FOR THIS
AFTERNOON/EVENING CONTINUE TO CENTER ON LOCALLY HEAVY
RAINFALL/MINOR FLOODING AND A FEW STRONG TSTMS. NOT UNCOMMON FOR
DEEP SUMMER, AN ISOLATED SEVERE TSTM WITH DAMAGING WINDS FROM
WET MICROBURSTS CAN NOT BE COMPLETELY RULED OUT. CONVECTION WILL
SLOWLY WIND DOWN THROUGH THE EVENING HOURS, BUT LINGERING
OUTFLOW BOUNDARIES AND WARM/MOIST CONDITIONS COULD SUPPORT SOME
DEGREE OF CONVECTION OVERNIGHT, SIMILAR TO WHAT OCCURRED LAST
NIGHT. LOWS TONIGHT WILL RANGE FROM THE MID 70S WELL INLAND TO
THE UPPER 70S/LOWER 80S AT THE COAST AND BEACHES.
AS FOR THE HEAT ADVISORY, HEAT INDICES ARE NEARING THE 108 MARK
ACROSS PARTS OF SOUTHEAST GEORGIA UP INTO THE BEAUFORT COUNTY
AREA. EVEN UP IN CHARLESTON WHERE CONVECTION HAS BEEN OFF AND ON
FOR THE PAST FEW HOURS, SOME LOCATIONS ARE ALREADY SEEING HEAT
INDICES NEAR 110. THE HEAT ADVISORY WILL REMAIN IN EFFECT UNTIL
8 PM AS IT IS CURRENTLY DEFINED, BUT SOME CLEARING OF COUNTIES
MAY BE NEEDED LATER THIS AFTERNOON AS CONVECTION EXPANDS.
SHORT TERM /THURSDAY THROUGH SATURDAY/
AS THIS SUBTROPICAL RIDGE WEAKENS, MULTIPLE SHORTWAVES ALOFT
WILL CARVE OUT AN UPPER-LVL TROUGH ACROSS THE EASTERN CONUS. AT
THE SURFACE, A REASONABLY STRONG COLD FRONT FOR EARLY AUGUST
WILL START TO PUSH INTO THE REGION AT THE LEADING EDGE OF THIS
AFOREMENTIONED UPPER-LVL TROUGH. AMPLE MOISTURE AND INSTABILITY
WILL PROMOTE HEAVY TO EXCESSIVE RAINFALL IN SHOWERS AND/OR
THUNDERSTORMS THAT COULD CAUSE LOCALIZED FLASH FLOODING. IN
ADDITION, WPC HAS PLACED THE REGION UNDER A SLIGHT RISK FOR
EXCESSIVE RAINFALL ON FRIDAY AND SATURDAY. IN REGARD TO
TEMPERATURES, EXPECT HIGHS TO REACH INTO THE MID TO UPPER 90S ON
THURSDAY AND FRIDAY WITH DEWPOINTS RANGING IN THE MID TO UPPER
70S. A HEAT ADVISORY WAS ISSUED FOR TOMORROW (11AM TO 8PM
EDT)FOR COUNTIES ALONG AND EAST OF I-95 AS HEAT INDICES ARE
EXPECTED TO REACH INTO THE 108 TO 112 DEGREES RANGE. FRIDAY
COULD WARRANT ANOTHER HEAT ADVISORY, HOWEVER SHOWERS AND/OR
THUNDERSTORMS MIGHT LIMIT AFTERNOON HEATING. AS THIS COLD FRONT
CONTINUES TO DROP SOUTHEASTWARD ACROSS THE REGION, TEMPERATURES
WILL FINALLY COOL DOWN ON SATURDAY, WITH HIGHS ONLY REACHING
INTO THE MID 80S TO LOW 90S UNDER CLOUDY SKIES. THIS WILL BE
ENOUGH TO LIMIT HEATING SATURDAY, AND AN ADDITIONAL HEAT
ADVISORY MAY NOT BE NEEDED.
LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/
THIS WET AND UNSETTLED PATTERN WILL CONTINUE THROUGH THE EARLY
NEXT WEEK AS THIS COLD FRONT STALLS NEARBY AND MEANDERS ALONG
THE COASTLINE. WITH PWATS 2.0+ INCHES AND DECENT INSTABILITY
STICKING AROUND, SCATTERED CONVECTION ACROSS THE REGION SHOULD
BE MAINTAINED. PERIODS OF LOCALLY HEAVY RAINFALL WILL BE
POSSIBLE WITHIN THESE SHOWERS AND/OR THUNDERSTORMS THAT TRACK
OVER AN AREA FOR AN EXTENDED PERIOD OF TIME. CONFIDENCE STILL
REMAINS LOW IF THE FLASH FLOODING WILL BE ENOUGH TO WARRANT A
FLOOD WATCH. ADDITIONALLY, WPC CONTINUES TO SHOW 3 TO 5 INCHES
OF RAINFALL ACROSS OUR AREA ON THE 7-DAY QPF FORECAST, WITH THE
MAJORITY OF THESE VALUES FALLING SATURDAY THROUGH MONDAY. ON A
POSITIVE NOTE, THIS PATTERN WILL ALLOW FOR A REFRESHING CHANGE
OF COOLER TEMPERATURES THROUGH EARLY NEXT WEEK WITH HIGHS ONLY
REACHING INTO THE LOW TO MID 80S.
AVIATION /16Z WEDNESDAY THROUGH SUNDAY/
30/18Z TAF DISCUSSION:
KCHS/KJZI: TSTMS WILL MEANDER NEAR KCHS FOR THE NEXT FEW HOURS.
VCTS WAS HIGHLIGHTED AT BOTH TERMINALS THROUGH MID-AFTERNOON
WITH TEMPO FOR DIRECT IMPACTS AT KCHS ROUGHLY THROUGH 20-21Z.
VFR SHOULD PREVAIL FOR THE REMAINDER OF THE NIGHT, ALTHOUGH WITH
MOIST/HUMID CONDITIONS HOLDING IN PLACE THROUGH SUNRISE, AN
ISOLATED NOCTURNAL SHOWER/TSTM CAN NOT BE COMPLETELY RULED OUT.
KSAV: THE TERMINAL WILL REMAIN DRY THROUGH THE REMAINDER OF THE
AFTERNOON WITH CONVECTION EXPECTED TO CONCENTRATE TO THE WEST.
SOME ACTIVITY COULD MEANDER INTO THE TERMINAL LATER THIS
EVENING, WHICH WAS HANDLED WITH A VCTS 00-04Z. VFR SHOULD PREVAIL
FOR THE REMAINDER OF THE NIGHT, ALTHOUGH WITH MOIST/HUMID
CONDITIONS HOLDING IN PLACE THROUGH SUNRISE, AN ISOLATED
NOCTURNAL SHOWER/TSTM CAN NOT BE COMPLETELY RULED OUT.
EXTENDED AVIATION FORECAST: THE RISK FOR FLIGHT RESTRICTIONS DUE TO
SHOWERS/TSTMS WILL PERSIST EACH AFTERNOON/EVENING WITH CHANCES
RAMPING UP OVER THE WEEKEND.
MARINE
TONIGHT: SOUTHERLY WINDS WILL VEER TO THE SOUTHWEST OVERNIGHT.
SPEEDS WILL REMAIN LESS THAN 15 KT WITH SEAS 1-3 FT.
THURSDAY THROUGH SUNDAY: EXPECT SOUTHERLY WINDS AT 10 TO 15 KT
THROUGH FRIDAY, WITH WINDS TURNING TO THE NORTHEAST OVER THE
WEEKEND AS A REASONABLY STRONG COLD FRONT FOR EARLY AUGUST
STALLS NEARBY OVER THE WEEKEND. IT COULD BECOME GUSTY OVER THE
WEEKEND (MAINLY ON SUNDAY AFTERNOON) ACROSS THE NEARSHORE SOUTH
CAROLINA WATERS AS THE GRADIENT PINCHES BEHIND THE COLD FRONT.
EXPECT SEAS TO BE 2 TO 3 FT, AND THEN BEGIN TO BUILD 3 TO 5 FT
ON SUNDAY (MAINLY ACROSS SOUTH CAROLINA NEARSHORE WATERS).
OTHERWISE, NO MARINE CONCERNS.
CLIMATE
RECORD HIGH MINIMUM TEMPERATURES:
JULY 31:
KCHS: 80/2022
KSAV: 80/2010
AUGUST 1:
KCHS: 81/1999
KSAV: 79/2020
CHS WATCHES/WARNINGS/ADVISORIES
GA...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR GAZ099>101-
114>119-137>141.
HEAT ADVISORY FROM 11 AM TO 8 PM EDT THURSDAY FOR GAZ099>101-
114>119-137>141.
SC...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR SCZ047>052.
HEAT ADVISORY FROM 11 AM TO 8 PM EDT THURSDAY FOR SCZ047>052.
MARINE...NONE.
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