370
FXUS62 KCHS 271742
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
142 PM EDT WED AUG 27 2025
SYNOPSIS
EXPECT DRY AND COOL CONDITIONS AS HIGH PRESSURE PREVAILS
THROUGH THURSDAY. THEREAFTER, A STATIONARY FRONT SHOULD REMAIN
TO THE SOUTH OF THE REGION THROUGH THE WEEKEND, AND CAUSE FOR
UNSETTLED CONDITIONS TO RETURN ON FRIDAY.
NEAR TERM /THROUGH TONIGHT/
SIMPLY OUTSTANDING CONDITIONS ACROSS THE SOUTH CAROLINA LOWCOUNTRY
AND SOUTHEASTERN GEORGIA THIS AFTERNOON, WITH TEMPERATURES IN THE
LOWER 80S AND DEWPOINTS IN THE UPPER 50S TO LOWER 60S ACCOMPANIED BY
MOSTLY CLEAR SKIES. AS A SURFACE HIGH PRESSURE MEANDERS CLOSER TO
THE AREA FROM THE NORTHWEST, SURFACE WINDS WILL REMAIN OUT OF THE
EAST-NORTHEAST, WITH A SEA BREEZE ATTEMPTING TO PUSH ASHORE ALSO
KEEPING WINDS OUT OF THE NORTHEAST BEHIND IT. AS EVIDENT BY RADAR
AND SATELLITE, VERY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE
OCCURRING ACROSS PORTIONS OF THE SOUTHEASTERN GEORGIA NEARSHORE
WATERS. THIS IS OCCURRING AS WEAK CYCLOGENESIS ATTEMPTS TO GET
GOING SOUTH OF THE REGION NEAR THE FRONT, WITH WEAK SHORTWAVES
PASSING OVERHEAD. NBM HAS THE HIGHEST CHANCES FOR A STRAY
SHOWER/STORM IS THUS HIGHEST ACROSS OUR EXTREME SOUTH NEAR
DARIEN, RIGHT AT 20% BY THE MID-AFTERNOON WITH PROBABILITIES
RAPIDLY DECREASING INTO THE LATE AFTERNOON HOURS. THE HREF AND
THE NEW REFS WOULD SUGGEST SLIGHTLY HIGHER PROBABILITIES HANGING
ON FOR AN ADDITIONAL HOUR OR TWO, THOUGH OTHER THAN SOME
MODERATE RAINFALL NOT EXPECTING ANY IMPACTS.
UPPER LEVEL CIRRUS WILL INCREASE TONIGHT FROM WEST TO EAST AS
ANOTHER SHORTWAVE BEGINS TO MOVE ACROSS THE REGION, WITH
TEMPERATURES DIURNALLY COOLING INTO THE MID 60S INLAND AND MID 70S
ALONG THE COAST.
SHORT TERM /THURSDAY THROUGH SATURDAY/
AT THE SURFACE, HIGH PRESSURE WILL START TO ERODE ON THURSDAY AS A
MID-LVL TROUGH SITUATED OVER THE GREAT LAKES BEGINS TO STRENGTHEN
AND SHIFT SOUTHEASTWARD TOWARDS THE REGION. SIMULTANEOUSLY, A WEAK
LOW LOCATED OVER THE NORTHERN GULF COULD DEVELOP AND MOVE SLOWLY
ACROSS THE FLORIDA PENINSULA WITH A FRONTAL BOUNDARY. THIS LOW
SHOULD MOVE OFFSHORE BY FRIDAY MORNING AS THIS FRONTAL BOUNDARY
REMAINS TO THE SOUTH THROUGH THE WEEKEND. THIS WILL INCREASE THE
CHANCES FOR PRECIPITATION ON FRIDAY AND SATURDAY, WITH POPS PEAKING
50-70% ON SATURDAY AFTERNOON. IT'S STILL UNCERTAIN HOW MUCH COVERAGE
THERE WILL BE AS IT'S VERY DEPENDENT ON THE EVOLUTION OF THIS LOW.
HOWEVER, THE SEVERE THREAT REMAINS LOW AS INSTABILITY LOOKS LIMITED,
BUT BRIEF LOCALLY HEAVY RAINFALL IS STILL POSSIBLE. WPC HAS
HIGHLIGHTED THE REGION UNDER A MARGINAL RISK (LEVEL 1 OF 4) FOR
EXCESSIVE RAINFALL FOR BOTH OF THESE DAYS. EXPECT TEMPERATURES TO
REACH INTO THE MID TO UPPER 80S ON THURSDAY AND FRIDAY, AND A LOW
80S ON SATURDAY DUE TO INCREASED CLOUD/PRECIP. CHANCES.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/
AS AN AMPLIFIED UPPER-LVL TROUGH CENTERS ITSELF OVER THE EASTERN
CONUS, CAUSING POSSIBLY MULTIPLE SHORTWAVES TO PASS THROUGH THE
REGION ALLOW UNSETTLED CONDITIONS TO CONTINUE THROUGH EARLY NEXT
WEEK. YET AGAIN, WPC HAS PLACED THE REGION UNDER A MARGINAL RISK
(LEVEL 1 OF 4) FOR EXCESSIVE RAINFALL FOR SUNDAY. ADDITIONALLY,
ANOTHER WEAK LOW PRESSURE COULD FORM OFFSHORE EARLY NEXT WEEK AND
CONTINUE ON THE ONSET OF UNSETTLED CONDITIONS. HOWEVER, CONFIDENCE
REMAINS LOW FOR THE EARLY PART OF NEXT WEEK AS MODELS CONTINUE TO
HIGHLY DIFFER, BUT HOPEFULLY THIS IMPROVES IN THE NEXT FORECAST
CYCLE. TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL FOR THIS TIME OF
YEAR.
AVIATION /18Z WEDNESDAY THROUGH MONDAY/
18Z TAFS: VFR ACROSS THE REGION THROUGH 18Z THURSDAY. WIND
DIRECTION OUT OF THE EAST-NORTHEAST WILL REMAIN FAVORED, THOUGH
WINDS WILL BECOME LIGHT AND VARIABLE FOR A FEW HOURS OVERNIGHT.
EXTENDED AVIATION FORECAST: VFR CONDITIONS EXPECTED TO LARGELY
PREVAIL, WITH BRIEF PERIODS OF FLIGHT RESTRICTIONS POSSIBLE BY THE
END OF THE WEEK AS CHANCES FOR SHOWERS/THUNDERSTORMS INCREASE.
MARINE
SURFACE HIGH PRESSURE WILL CONTINUE TO LINGER ACROSS THE MARINE
ZONES INTO TONIGHT. WINDS SHOULD GENERALLY FAVOR A NORTHEAST
DIRECTION AT AROUND 10 KTS. SEAS SHOULD RANGE AROUND 2 FT TODAY
AND TONIGHT. BEYOND 40 NM FROM SHORE, SEAS COULD APPROACH 3 FT
AT TIMES. NEAR AND OFFSHORE WATERS FROM SAVANNAH GA TO ALTAMAHA
SOUND GA HAVE A CHANCE (20-30%) FOR SCATTERED SHOWERS AND
THUNDERSTORMS CONTINUING INTO THE OVERNIGHT HOURS.
THURSDAY THROUGH MONDAY: AS SURFACE HIGH PRESSURE DOMINATES THE
FORECAST, A WEAK AREA OF LOW PRESSURE LOCATED IN THE NORTHERN GULF
COULD MOVE ACROSS THE FLORIDA PENINSULA ALONG A FRONTAL BOUNDARY AND
THEN SHIFT OFFSHORE BY FRIDAY MORNING. THIS FRONTAL BOUNDARY SHOULD
STAY TO THE SOUTH OF THE REGION. EXPECT EAST-NORTHEASTERLY WINDS TO
REMAIN ACROSS THE ATLANTIC UNTIL EARLY NEXT WEEK. IT COULD BECOME
QUITE GUSTY ON SUNDAY AND MONDAY AS ANOTHER LOW TRIES TO POTENTIALLY
DEVELOP OFFSHORE EARLY NEXT WEEK. OTHERWISE, NO MARINE CONCERNS ARE
ANTICIPATED THROUGH THIS PERIOD.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
NEAR TERM...APT
SHORT TERM...DENNIS
LONG TERM...DENNIS
AVIATION...APT/DENNIS
MARINE...APT/DENNIS
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