497
FXUS62 KCHS 160001
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
801 PM EDT SAT AUG 15 2026
WHAT HAS CHANGED
THE AVIATION SECTION WAS UPDATED FOR THE 00Z TAFS.
KEY MESSAGES
- 1) HEAT WILL REMAIN A CONCERN INTO THE MIDDLE OF NEXT WEEK.
- 2) STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON
AND SUNDAY AFTERNOON.
DISCUSSION
KEY MESSAGE 1: HEAT WILL REMAIN A CONCERN INTO THE MIDDLE OF NEXT
WEEK.
A RATHER LONG DURATION HEAT WAVE HAS TAKEN HOLD ACROSS THE AREA
AND RELIEF FROM THE HEAT DOES NOT LOOK TO COME UNTIL LATER
NEXT WEEK. LARGE-SCALE RIDGING CENTERED ACROSS THE DEEP SOUTH
EXTENDING INTO THE COASTAL SOUTHEAST WILL REMAIN IN PLACE
THROUGH THE FORESEEABLE FUTURE LEADING TO CONTINUED HEAT ISSUES
THROUGH AT LEAST WEDNESDAY POSSIBLY THURSDAY OF NEXT WEEK.
AMPLE SUNSHINE WILL PROMOTE STRONG SFC HEATING EACH DAY WHILE A
WEST- NORTHWEST DOWNSLOPE FLOW PERSISTS ACROSS THE REGION.
GUIDANCE CONTINUES TO SUPPORT AFTERNOON HIGHS IN THE MID-UPPER
90S WITH A FEW LOCATIONS POTENTIALLY TOUCHING 100 DEGREES MAINLY
ON MONDAY AND TUESDAY OF THIS WEEK, WHICH COULD RESULT IN
RECORD WARMTH (SEE CLIMATE SECTION BELOW). HUMID CONDITIONS WILL
ALSO PERSIST WITH SFC DEWPTS IN THE MID-UPPER 70S EACH DAY.
ALTHOUGH THE DOWNSLOPE FLOW SHOULD RESULT IN A SLIGHTLY DELAYED
SEABREEZE AND SOME MIXING OUT OF SFC DEWPTS INLAND, MOISTURE
SHOULD POOL NEAR THE BOUNDARY AS IT SHIFTS INLAND AS WELL AS
BRING HIGHER MOISTURE CONTENT ONSHORE.
REST OF TODAY THROUGH SUNDAY: SO FAR OBSERVATIONS ACROSS THE
AREA ARE ON TRACK WITH WIDESPREAD 108 TO 113 HEAT INDICES
ACROSS THE AREA. THE HIGHEST HEAT INDICES LOOK TO BE ALONG THE
IMMEDIATE COASTLINE AS THE SEABREEZE HAS BEGUN ITS SLOW MARCH
INLAND. SCATTERED STORMS HAVE BEGUN TO DEVELOP THIS AFTERNOON
NORTH OF THE AREA ACROSS NORTHERN SC AND THIS ACTIVITY IS
EXPECTED TO SLOWLY BUILD SOUTHWARD INTO OUR AREA LIKELY BRINGING
TEMPORARY RELIEF TONIGHT FOR SOME LOCATIONS. FURTHER SOUTH
RELIEF MAY NOT COME; HOWEVER, CONFIDENCE ACROSS GEORGIA IN
HIGHER HEAT INDICES IS LOWER THUS THINGS SHOULD EVEN OUT ACROSS
THE BOARD TONIGHT. SUNDAY SHOULD HAVE SIMILAR RESULTS BASED ON
THE PERSISTENT PATTERN. HOWEVER, A SLIGHT UPTICK IN CONVECTIVE
COVERAGE IS POSSIBLE AS A SUBTLE SHORTWAVE MOVES ACROSS THE
AREA AND A WEAK BOUNDARY ENCROACHES FROM THE NORTH. STORMS MAY
ALSO BEGIN EARLIER IN THE DAY CLOSER TO THE NOON TIMEFRAME WHICH
WILL HELP "LIMIT" HOW HOT WE GET DURING THE AFTERNOON. GIVEN
SOME UNCERTAINTY IN CONVECTION TRENDS, HAVE OPTED TO GO WITH A
HEAT ADVISORIES OVER THE AREA.
EARLY TO MIDDLE OF NEXT WEEK: THE RESURGENCE IN THE HOT/HUMID
CONDITIONS LOOKS LIKELY ON MONDAY AND TUESDAY AS THE UPPER RIDGE
RESTRENGTHENS ACROSS THE AREA. RECORD WARMTH LOOKS POSSIBLE
WITH LATEST GUIDANCE SUGGESTING SEVERAL AREAS OF 100+ TEMPS
MONDAY/TUESDAY AND WITH LITTLE TO NO SHOWER/THUNDERSTORM
ACTIVITY. HEAT INDICES WILL LIKELY CLIMB INTO THE 110 TO 115
RANGE ALMOST AREA WIDE AND SOME ISOLATED COASTAL AREAS MAY
APPROACH HEAT INDICES OF NEAR 120. CONDITIONS STILL REMAIN HOT
HEADING THROUGH MID-WEEK AS THE UPPER RIDGE SLOWLY BACKS OFF
HEADING INTO THE WEEKEND. ADDITIONAL HEAT HEADLINES ARE LIKELY
EARLY INTO THE MIDDLE OF NEXT WEEK.
KEY MESSAGE 2: STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE THIS
AFTERNOON AND SUNDAY AFTERNOON.
THE HEAT AND HUMIDITY (MENTIONED IN KEY MESSAGE 1) WILL PROVIDE A
MODERATE AMOUNT OF INSTABILITY ACROSS OUR AREA THIS AFTERNOON AND
AGAIN SUNDAY AFTERNOON. DEPENDING ON THE MODEL, SBCAPE VALUES PEAK
IN THE 2,000-2,500 J/KG RANGE, WITH DCAPE VALUES UPWARDS OF 800
J/KG. THERE ARE SOME MINOR DIFFERENCES AMONGST THE VARIOUS NEAR-TERM
CAMS AND EVEN THE SYNOPTIC MODELS. BUT THE GENERAL CONSENSUS IS THAT
THERE SHOULD BE ISOLATED TO SCATTERED CONVECTION BOTH AFTERNOONS.
THE STORMS ARE MOST LIKELY TO START ALONG THE SEA BREEZE AND THEN
SHIFT INLAND, WITH OUTFLOW AND BOUNDARY INTERACTIONS PLAYING A ROLE
IN STORM FORMATION AND PERSISTENCE. GIVEN THE AFOREMENTIONED
INSTABILITY, STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE. THE MAIN
THREAT WOULD BE DAMAGING WINDS. BUT HEAVY RAINFALL IS ALSO A CONCERN
DUE TO WEAK STEERING FLOW. BACKBUILDING AND/OR TRAINING OF STORMS
COULD DROP ENOUGH RAINFALL TO GENERATE VERY LOCALIZED FLOODING. THE
CONVECTION EACH AFTERNOON IS EXPECTED TO DISSIPATE EACH EVENING.
AVIATION /00Z SUNDAY THROUGH THURSDAY/
00Z TAF DISCUSSION: A CLUSTER OF STRONG STORMS ARE ONGOING
ACROSS CHARLESTON/DORCHESTER/COLLETON COUNTIES. THESE STORMS
WILL LIKELY PERSIST FOR ANOTHER COUPLE OF HOURS, BUT THEY ARE
MOVING SOUTHWEST, AWAY FROM KCHS AND KJZI. SHOWERS WITH MINIMAL
IMPACTS COULD STILL AFFECT KCHS AND KJZI THROUGH AROUND 02Z
BEFORE COMPLETELY DISSIPATING. TEMPO GROUPS MAY NEED TO BE
INTRODUCED FOR THAT. OTHERWISE, VFR CONDITIONS ARE EXPECTED
OVERNIGHT AND INTO SUNDAY MORNING. ANOTHER AFTERNOON OF
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED SUNDAY, WHERE
PROB30 GROUPS HAVE BEEN INTRODUCED AT ALL TERMINALS.
EXTENDED AVIATION OUTLOOK: PERIODIC FLIGHT RESTRICTIONS ARE EXPECTED
IN SHOWERS AND THUNDERSTORMS THROUGH NEXT WEEK.
MARINE
THROUGH SUNDAY: SURFACE HIGH PRESSURE OVER THE WESTERN ATLANTIC WITH
WEAK INLAND TROUGHING WILL CONTINUE THE MOSTLY QUIET CONDITIONS OVER
THE WATERS. EXPECT WESTERLY TO SOUTHERLY WINDS THROUGHOUT THE
PERIOD, WITH THE BREEZIEST WINDS OCCURRING BOTH AFTERNOONS ALONG THE
LAND-SEA INTERFACE WITH GUSTS TO 20 KNOTS. THUNDERSTORMS THAT
DEVELOP OVER LAND THIS AFTERNOON AND SUNDAY AFTERNOON COULD SHIFT
OFFSHORE DURING THE LATER AFTERNOON INTO EARLY EVENING HOURS. A FEW
THUNDERSTORMS COULD REMAIN STRONG WHEN SHIFTING ACROSS COASTAL AREAS.
MONDAY - WEDNESDAY: THERE WILL BE AREAS OF HIGH PRESSURE IN THE
WESTERN ATLANTIC AND THE NORTHERN GULF, WHILE SURFACE TROUGHING WILL
BE OVER THE SOUTHEAST U.S. THE INTERACTION BETWEEN ALL OF THESE
SYNOPTIC FEATURES WILL GENERATE A TYPICAL SUMMERTIME WIND PATTERN.
WINDS WILL GENERALLY BE FROM THE SW, BACKING A BIT EACH DAY AND
VEERING SOME EACH NIGHT. THE STRONGEST WINDS SHOULD BE DURING THE
DAY, ESPECIALLY CLOSER TO THE COAST DUE TO THE SEA BREEZE. SEAS WILL
MAINLY BE IN THE 2-3 FT RANGE.
CLIMATE
RECORD HIGH TEMPERATURES:
AUGUST 14:
KCHS: 102/1995
KSAV: 102/1925
AUGUST 15:
KCHS: 96/2023
KCXM: 99/1918
KSAV: 100/1918
AUGUST 16:
KCHS: 99/1954
KSAV: 100/1954
AUGUST 17:
KCHS: 102/1954
KSAV: 102/1954
AUGUST 18:
KCHS: 101/1995
KCXM: 97/1995
KSAV: 100/1995
AUGUST 19:
KCHS: 98/1983
KSAV: 99/1900
AUGUST 20:
KCHS: 97/2005
KSAV: 102/1900
RECORD HIGH MINIMUM TEMPERATURES:
AUGUST 14:
KCHS: 80/2023
KCXM: 83/2023
KSAV: 80/2023
AUGUST 15:
KCHS: 78/1995
KCXM: 83/2021
KSAV: 80/1995
AUGUST 16:
KCHS: 78/2019
KCXM: 83/2016
KSAV: 78/2019
AUGUST 17:
KCHS: 80/2017
KCXM: 83/2017
KSAV: 78/2017
AUGUST 18:
KCHS: 80/2017
KCXM: 82/2017
KSAV: 78/2010
AUGUST 19:
KCHS: 79/2010
KCXM: 83/2021
KSAV: 79/1878
AUGUST 20:
KCHS: 78/2017
KCXM: 82/2017
KSAV: 82/1878
CHS WATCHES/WARNINGS/ADVISORIES
GA...HEAT ADVISORY FROM 11 AM TO 8 PM EDT SUNDAY FOR GAZ087-088-
099>101-114-115-137-216>219-238>241.
SC...HEAT ADVISORY FROM 11 AM TO 8 PM EDT SUNDAY FOR SCZ040-042>045-
147>152.
MARINE...NONE.
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