820
FXUS62 KCHS 261129
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
729 AM EDT SUN JUL 26 2026
WHAT HAS CHANGED
THE AVIATION SECTION HAS BEEN UPDATED TO REFLECT THE 12Z TAFS.
KEY MESSAGES
- 1) LOCALLY HEAVY RAINFALL IS POSSIBLE TODAY AS A STALLED
FRONT REMAINS IN THE VICINITY OF THE SOUTH CAROLINA
LOWCOUNTRY.
- 2) HOT AND HUMID CONDITIONS RETURN TO THE SOUTH CAROLINA
LOWCOUNTRY AND SOUTHEAST GEORGIA DURING THE MIDDLE OF THIS
WEEK.
DISCUSSION
KEY MESSAGE 1: LOCALLY HEAVY RAINFALL IS POSSIBLE TODAY AS A
STALLED FRONT REMAINS IN THE VICINITY OF THE SOUTH CAROLINA
LOWCOUNTRY.
THE STATIONARY FRONT THAT HAS BEEN LINGERING IN THE VICINITY OF THE
FORECAST AREA THE LAST COUPLE OF DAYS HAS SHIFTED SLIGHTLY, TAKING
ON A MORE NORTHWEST TO SOUTHEAST ORIENTATION. WITH THE REGION STILL
LOCATED ALONG THE SOUTHERN PERIPHERY OF A MID-LEVEL TROUGH,
THIS FRONTAL ORIENTATION IS IN ALIGNMENT WITH THE MEAN FLOW. AS
OF THE 03Z WPC SURFACE ANALYSIS, THE FRONT IS LOCATED IN THE
VICINITY OF MYRTLE BEACH. THROUGH THE REMAINDER OF THE OVERNIGHT
HOURS AND INTO THIS MORNING THE FRONT IS EXPECTED TO SAG
SOUTHWARD TOWARDS THE CHARLESTON TRI-COUNTY. WITH THE FRONT
ORIENTED ALONG THE MEAN SYNOPTIC FLOW, ROUNDS OF SHOWERS AND
THUNDERSTORMS ARE FORECAST TO RIPPLE SOUTHEASTWARD ALONG THE
FRONT THROUGH THE DAY TODAY. HEAVY RAINFALL REMAINS THE MAIN
FORECAST CONCERN TODAY, WITH PLENTIFUL MOISTURE ACROSS THE
REGION. THE KCHS 00Z RAOB SOUNDING HAD A PWAT VALUE OF 2.36",
WHICH WAS WELL ABOVE THE 90TH PERCENTILE ACCORDING TO SPC
CLIMATOLOGY. PWATS ARE EXPECTED TO REMAIN IN THE 2.3-2.5" RANGE
THROUGH THE REMAINDER OF TODAY. THE HEAVY RAINFALL THREAT TODAY
WILL BE HEAVILY TIED TO THE LOCATION OF THE FRONT. THE 00Z SUITE
OF GUIDANCE IS IN DECENT AGREEMENT THAT THE FRONT WILL LIKELY
SET UP ROUGHLY ALONG I-26 IN SC. THIS WOULD PAINT THE GREATEST
HEAVY RAINFALL THREAT OVER THE CHARLESTON TRI-COUNTY. THE 00Z
HREF PROBABILITIES ARE EYE-CATCHING, WITH A 50% CONTOUR OF 3-HR
QPF >3" OVER THE CHARLESTON TRI-COUNTY AT 21Z. CONFIDENCE ON THE
EXACT POSITIONING OF THE FRONT IS LOW AND A SLIGHT SHIFT
NORTHWARD OR SOUTHWARD WOULD GREATLY IMPACT THE LOCATION OF THE
HEAVY RAINFALL THREAT. ANOTHER CONSIDERATION IS SOME MODELS ARE
DEPICTING A WEAK LOW PRESSURE CENTER DEVELOPING ALONG THE
STALLED FRONT, WHICH WOULD AID IN THE HEAVY RAINFALL RISK.
FORECAST SOUNDINGS INDICATE SUFFICIENT INSTABILITY FOR A RISK OF
STRONG TO SEVERE GUSTS AS WELL, AND THE STORM PREDICTION CENTER
HAS OUTLINED THE ENTIRE FORECAST AREA IN A MARGINAL RISK FOR
SEVERE THUNDERSTORMS.
KEY MESSAGE 2: HOT AND HUMID CONDITIONS RETURN TO THE SOUTH
CAROLINA LOWCOUNTRY AND SOUTHEAST GEORGIA DURING THE MIDDLE OF
THIS WEEK.
THE MID-LEVELS WILL CONSIST OF A VERY STRONG RIDGE OVER THE ROCKIES
AND PLAINS EARLY TO MID WEEK. MEANWHILE, TROUGHING WILL BE
ALONG THE EASTERN SEABOARD. WE'LL GENERALLY BE ON THE EASTERN
PERIPHERY OF THE RIDGE, WITH NNW FLOW OVERHEAD. AT THE SURFACE,
WEAK HIGH PRESSURE WILL PREVAIL OVER OR NEARBY EARLY TO MID NEXT
WEEK. HOT AND HUMID CONDITIONS ARE EXPECTED TO RETURN DURING
THE MIDDLE OF THE WEEK. TUESDAY AND WEDNESDAY LOOK TO BE THE
HOTTEST DAYS OF THE WEEK, WITH HIGHS IN THE MID TO UPPER 90S,
WITH SOME SPOTS POSSIBLY REACHING THE 100 DEGREE MARK ACROSS FAR
INLAND GA. EVEN TEMPERATURES AT THE COAST WILL BE IN THE 90S.
DEWPOINTS ARE EXPECTED TO BE IN THE LOW 70S FAR INLAND, BUT POOL
INTO THE MID TO UPPER 70S AT THE COAST WITH THE AFTERNOON SEA
BREEZE. THIS WILL EQUATE TO HEAT INDICES IN THE 100-105 DEGREE
RANGE INLAND, AND THE 108-112 DEGREE RANGE FOR OUR COASTAL
COUNTIES ON TUESDAY. THOUGH, THE RANGE COULD INCREASE TO 110-115
DEGREES FOR OUR COASTAL COUNTIES ON WEDNESDAY. IF THIS PANS
OUT, AT LEAST OUR COASTAL COUNTIES WOULD NEED HEAT HEADLINES
BOTH DAYS. THE WILD CARD WOULD BE AFTERNOON CONVECTION. TUESDAY
IS LOOKING FAIRLY DRY, BUT WEDNESDAY MAY HAVE SCATTERED
CONVECTION, WHICH WOULD QUICKLY LOWER TEMPERATURES. IT COULD
ALSO LEAD TO STRONG TO MARGINALLY SEVERE STORMS. THE HEAT AND
HUMIDITY IS EXPECTED TO DROP TO NEAR NORMAL VALUES ON THURSDAY
WITH THE ARRIVAL OF A FRONT.
AVIATION /12Z SUNDAY THROUGH THURSDAY/
VFR TO START THE 12Z TAF PERIOD AT KCHS/KJZI/KSAV. A STATIONARY
FRONT IS LOCATED JUST TO THE NORTH OF CHARLESTON AND BERKELEY
COUNTIES AS OF 11Z. RESTRICTIONS ARE POSSIBLE AT KCHS/KJZI THIS
AFTERNOON AS SHOWERS AND THUNDERSTORMS DEVELOP ASSOCIATED WITH
THE STALLED FRONT. THIS THREAT IS HIGHLIGHTED WITHIN A TEMPO
GROUP AT BOTH TERMINALS, WHILE KSAV REMAINS PRECIP FREE AT THIS
JUNCTURE.
EXTENDED AVIATION OUTLOOK: BRIEF FLIGHT RESTRICTIONS ARE POSSIBLE
WEDNESDAY AND THURSDAY DUE TO SHOWERS AND THUNDERSTORMS.
MARINE
THROUGH FRIDAY: A STATIONARY FRONT NEARBY WILL CONTINUE
SOUTHWESTERLY WINDS TODAY. WINDS AND SEAS ARE FORECAST TO
INCREASE LATE TUESDAY INTO WEDNESDAY, SO SMALL CRAFT ADVISORIES
MAY BE NEEDED FOR MOST OF OUR WATERS.
CLIMATE
RECORD HIGH TEMPERATURES:
JULY 28:
KCHS: 101/1949
KCXM: 100/1936
KSAV: 102/1949
JULY 29:
KCHS: 100/1993
KCXM: 99/1999
KSAV: 103/1993
RECORD HIGH MINIMUM TEMPERATURES:
JULY 29:
KCHS: 80/2016
KCXM: 85/1999
KSAV: 82/1878
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page