836
FXUS62 KCHS 191830
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
230 PM EDT WED AUG 19 2026
WHAT HAS CHANGED
ALL SECTIONS HAVE BEEN UPDATED.
KEY MESSAGES
- 1) HEAT WILL REMAIN A CONCERN INTO LATE WEEK.
- 2) AFTERNOON AND EVENING THUNDERSTORM COVERAGE WILL REMAIN
ISOLATED THROUGH THURSDAY. AN INCREASE IN THUNDERSTORM
COVERAGE IS EXPECTED FRIDAY THROUGH THE WEEKEND.
DISCUSSION
KEY MESSAGE 1: HEAT WILL REMAIN A CONCERN INTO LATE WEEK.
COASTAL TROUGHING AT THE SURFACE WITH RIDGING ALOFT WILL CONTINUE
THE HEAT WAVE INTO THE END OF THE WEEK. TEMPERATURES ARE IN THE MID-
UPPER 90S THIS AFTERNOON, WITH A FEW MORE DEGREES LIKELY BEFORE PEAK
HEATING ENDS. AREAS ALONG/WEST OF THE I-95 CORRIDOR WILL CONTINUE TO
SEE A WESTERLY COMPONENT TO THE WINDS THIS AFTERNOON, WHICH WILL
ADVECT AND MIX IN SOME DRIER AIR INTO THE ENVIRONMENT. THIS WILL
RESULT IN DEW POINTS DROPPING DOWN INTO THE UPPER 60S TO LOWER 70S,
KEEPING HEAT INDEX VALUES IN THE 100-107 DEGREE RANGE THIS
AFTERNOON. AREAS ALONG THE COAST WILL SEE A SEA-BREEZE PUSH ASHORE
THIS AFTERNOON, KEEPING DEWPOINTS IN THE MID TO UPPER 70S WHICH WILL
RESULT IN HEAT INDEX VALUES OF 108-112 DEG F THIS AFTERNOON. WHILE
WE MAY END UP ON THE UPPER END OF GUIDANCE TODAY, THE PREVIOUSLY
ISSUED HEAT ADVISORY LOOKS TO BE IN GOOD SHAPE. DAILY HIGHS AND
DAILY HIGH MINIMUMS ARE BOTH POSSIBLE TODAY, FOR MORE SEE THE
CLIMATE SECTION BELOW.
RINSE AND REPEAT FOR THURSDAY AND FRIDAY. GIVEN THE CONTINUATION OF
SIMILAR CONDITIONS, HAVE ISSUED ANOTHER HEAT ADVISORY FOR THE
COASTAL CORRIDOR AND INLAND BERKELEY COUNTY THURSDAY FROM 11 AM TO 8
PM, WHERE HEAT INDEX VALUES WILL PEAK FROM 108 TO 112 DEG F. FRIDAY
LOOKS BE A TOUCH COOLER GIVEN SLIGHTLY EARLIER SHOWER/THUNDERSTORM
INITIATION AND MORE AREAL COVERAGE, BUT WILL LIKELY SEE SIMILAR
COVERAGE OF HEAT PRIOR TO SHOWERS/STORMS STARTING.
AN INCREASE IN SHOWER AND THUNDERSTORM ACTIVITY THIS WEEKEND LOOKS
TO COOL US OFF ENOUGH TO POSSIBLY GO WITHOUT ANY HEAT
ADVISORIES/WARNINGS, THOUGH HIGH TEMPERATURES LOOK TO STILL PEAK IN
THE LOWER TO MID 90S.
KEY MESSAGE 2: AFTERNOON AND EVENING THUNDERSTORM COVERAGE WILL
REMAIN ISOLATED THROUGH THURSDAY. AN INCREASE IN THUNDERSTORM
COVERAGE IS EXPECTED FRIDAY THROUGH THE WEEKEND.
COASTAL TROUGHING AT THE SURFACE AND RIDGING ALOFT WILL ALLOW FOR
ISOLATED CHANCES FOR SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON
AND EVENING HOURS TODAY AND THURSDAY. SHOWERS/STORMS WILL LIKELY
INITIATE OFF OF EITHER THE COASTAL TROUGH OR THE EXPECTED SEA-
BREEZE, BUT AS NEITHER WILL BE PARTICULARLY FAST MOVING, ONLY A FEW
ISOLATED SHOWERS AND STORMS ARE EXPECTED. MODELS CONTINUE TO SUGGEST
PORTIONS OF SOUTHEAST SOUTH CAROLINA ARE THE PRIMARY REGION WHERE
RAINFALL IS POSSIBLE, WITH PROBABILITIES IN THE 20-40% CHANCE RANGE.
SIMILAR TO THE PAST COUPLE DAYS, WHILE THE ENVIRONMENT HAS 2000-2500
J/KG OF CAPE RESULTING IN THE POSSIBILITY OF AN ISOLATED STRONG-
SEVERE THUNDERSTORM, THE LACK OF FORCING AND THE LACK OF SHEAR AND
UPPER LEVEL FLOW HAS KEPT SUCH ACTIVITY FROM OCCURRING WHICH SHOULD
CONTINUE TODAY. EXPECT A SIMILAR REPEAT OF SHOWER AND THUNDERSTORM
CHANCES FOR THURSDAY.
FRIDAY AND INTO THE WEEKEND, A SLOW MOVING TROUGH BEGINS TO MOVE
ACROSS THE REGION, INCREASING RAINFALL CHANCES INTO THE WEEKEND.
WITH TEMPERATURES REMAINING NEAR/ABOVE NORMAL, SBCAPE AND DCAPE
VALUES COULD STILL GET QUITE ELEVATED. STRONG TO SEVERE
THUNDERSTORMS REMAIN POSSIBLE EACH AFTERNOON WITH THE MAIN
THREAT BEING DAMAGING WINDS. HEAVY RAINFALL WILL ALSO BE CONCERN
DUE TO THE VERY WEAK STEERING WINDS AND ELEVATED PWATS.
AVIATION /18Z WEDNESDAY THROUGH MONDAY/
18Z TAFS - GENERALLY VFR CONDITIONS EXPECTED, THOUGH THE RISK FOR
ISOLATED SHOWERS AND THUNDERSTORMS BUILDS THIS AFTERNOON, WITH
GREATEST CHANCES (~20-40%) FOR PORTIONS OF SOUTHEAST SOUTH CAROLINA.
STORMS WILL LIKELY HOLD OFF ON INITIATING UNTIL THE SEA BREEZE
PUSHES NORTH-NORTHWEST OF JZI, BUT DID INCLUDE A PROB30 FOR CHS AS
CHANCES INCREASE INLAND. SAV LOOKS TO REMAIN CLEAR OF SHOWER/STORM
ACTIVITY. IN ADDITION TO POTENTIALLY PRODUCING MVFR CONDITIONS, A
FEW THUNDERSTORMS COULD BE STRONG WITH GUSTY WINDS. RAIN CHANCES
DECREASE OVERNIGHT. AREAS THAT SEE DECENT AMOUNTS OF RAIN MAY SEE
PATCHY FOG INTO THURSDAY MORNING, BUT DID NOT INCLUDE ANY MENTION AT
THE TAF SITES. AFTER A QUIET MORNING, CHANCES FOR ISOLATED
SHOWERS/STORMS RETURN THURSDAY AFTERNOON.
EXTENDED AVIATION OUTLOOK: ISOLATED AFTERNOON FLIGHT RESTRICTIONS
ARE POSSIBLE IN SHOWERS AND THUNDERSTORMS ON THURSDAY. SHOWER AND
THUNDERSTORM CHANCES INCREASE FRIDAY INTO THE WEEKEND, BRINGING
ADDITIONAL CHANCES FOR BRIEF FLIGHT RESTRICTIONS.
MARINE
THERE ARE NO LARGE-SCALE MARINE CONCERNS. MORNINGS WILL GENERALLY
START OUT WITH SOUTH-SOUTHWESTERLY WINDS, INCREASING IN STRENGTH AS
THEY BECOME SOUTHEASTERLY IN THE AFTERNOON, AND BACK TO SOUTH-
SOUTHWESTERLY OVERNIGHT. SEAS MOSTLY IN THE 2-3 FT RANGE. THERE MAY
BE SOME ISOLATED SHOWERS/STORMS THAT MOVE OUT INTO THE WATERS TODAY
AND THURSDAY AFTERNOON, WITH COVERAGE INCREASING FRIDAY INTO THE
WEEKEND.
CLIMATE
RECORD HIGH TEMPERATURES:
AUGUST 19:
KCHS: 98/1983
KCXM: 98/1895
KSAV: 99/1900
AUGUST 20:
KCHS: 97/2005
KCXM: 99/1902
KSAV: 102/1900
AUGUST 21:
KCHS: 100/1983
KCXM: 99/1900
KSAV: 101/1902
RECORD HIGH MINIMUM TEMPERATURES:
AUGUST 19:
KCHS: 79/2010
KCXM: 83/2021
KSAV: 79/1878
AUGUST 20:
KCHS: 78/2017
KCXM: 82/2017
KSAV: 82/1878
AUGUST 21:
KCHS: 79/2010
KCXM: 82/2023
KSAV: 80/1902
AUGUST 22:
KCHS: 79/2023
KCXM: 82/2014
KSAV: 79/1902
AUGUST 23:
KCHS: 80/2014
KCXM: 81/2019
KSAV: 78/2016
CHS WATCHES/WARNINGS/ADVISORIES
GA...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR GAZ217>219-
239>241.
HEAT ADVISORY FROM 11 AM TO 8 PM EDT THURSDAY FOR GAZ217>219-
239>241.
SC...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR SCZ045-148>152.
HEAT ADVISORY FROM 11 AM TO 8 PM EDT THURSDAY FOR SCZ045-
148>152.
MARINE...NONE.
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