260
FXUS62 KCHS 201859
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
259 PM EDT SAT JUN 20 2026
WHAT HAS CHANGED
AREA OF GREATEST HEAVY RAINFALL THREAT THIS AFTERNOON HAS BEEN
REFINED TO NEAR AND SOUTH OF HINESVILLE.
THE LIKELIHOOD FOR HAZARDOUS HEAT ON MONDAY HAS DIMINISHED.
KEY MESSAGES
- 1) LOCALIZED FLASH FLOODING AND DAMAGING WIND GUSTS POSSIBLE
FOR PORTIONS OF SOUTHEAST GEORGIA THROUGH EARLY EVENING.
- 2) A FAIRLY TYPICAL SUMMERTIME PATTERN IS EXPECTED WITH DAILY
SHOWER AND THUNDERSTORM CHANCES.
- 3) HOT AND HUMID CONDITIONS LIKELY TO PEAK TUESDAY.
DISCUSSION
KEY MESSAGE 1: A WEAK FRONT CONTINUES TO SLOWLY SLIDE SOUTHWARD,
PUSHING JUST SOUTH OF I-16 EARLY THIS AFTERNOON. THIS FRONT WILL
LIKELY STALL AND WASH-OUT THROUGH THE REST OF THE DAY, BUT HAS
ALREADY POSITIONED THE BAND OF PRIMARY MOISTURE CONVERGENCE
ACROSS SOUTHEAST GA, WHERE PWAT VALUES HAVE SURPASSED 2 INCHES
AND MLCAPE IS APPROACHING 2000 J/KG.
STORM MOTION IS LIKELY TO BE MOSTLY EASTWARD AT 20+ MPH. THE
CONCERN IS THAT THE COLD POOL BUILDING INTO THE WESTERLY SHEAR
WILL RESULT IN TRAINING STORMS, WHICH COULD BRING MULTIPLE
ROUNDS OF DOWNPOURS NEAR OR SOUTH OF THE FRONT. GUIDANCE
CONTINUES TO FOCUS ON AREAS FROM AROUND HINESVILLE SOUTHWARD FOR
THE GREATEST PERSISTENT HEAVY RAINFALL THREAT, WITH PROBS FOR
GREATER THAN 2 IN OF 50-60% AND PROBS FOR GREATER THAN 3 IN OF
20-30% ACROSS THE CORRIDOR FROM HINESVILLE TO BRUNSWICK.
CONVECTIVE ACTIVITY IS EXPECTED TO WANE BY/AROUND SUNSET WITH
THE LOSS OF PEAK INSTABILITY. WHILE DEBRIS CLOUDS/CIRRUS WILL
LIKELY PERSIST THROUGH MUCH OF THE NIGHT, THERE IS A LOW CHANCE
THAT THERE WILL BE SUFFICIENT RADIATIONAL COOLING TO DEVELOP
SOME SHALLOW FOG EARLY SUNDAY MORNING WHERE RAIN FALLS THIS
AFTERNOON.
KEY MESSAGE 2: A FAIRLY TYPICAL SUMMERTIME PATTERN IS EXPECTED WITH
DAILY SHOWER AND THUNDERSTORM CHANCES.
THE MID-LEVELS WILL CONSIST OF A SERIES OF WEAK DISTURBANCES MOVING
OVER THE SOUTHEAST THE NEXT FEW DAYS. AT THE SURFACE, AREAS OF HIGH
PRESSURE WILL BE IN THE EASTERN GULF AND THE ATLANTIC, WHILE FRONTS
SHOULD GENERALLY REMAIN JUST TO OUR NORTH. ADDITIONALLY, THERE
SHOULD BE WEAK SURFACE TROUGHING OVER OUR REGION AT TIMES. THE
COMBINATION OF MOISTURE ACROSS OUR REGION AND INSTABILITY GENERATED
FROM THE TYPICAL JUNE HIGH TEMPERATURES WILL GENERATE SHOWERS AND
THUNDERSTORMS. ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON
SUNDAY, WITH THE COVERAGE INCREASING TO SCATTERED MONDAY AND
AFTERWARDS. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO PEAK IN THE
LATE AFTERNOON AND EARLY EVENINGS, WHEN INSTABILITY IS AT ITS
HIGHEST. THE THREAT FOR ORGANIZED SEVERE WEATHER IS LOW, BUT WE
CANNOT RULE OUT A COUPLE OF STRONG TO SEVERE STORMS EACH DAY.
KEY MESSAGE 3: HOT AND HUMID CONDITIONS LIKELY TO PEAK TUESDAY.
HIGH TEMPERATURES ARE FORECASTED TO PEAK IN THE LOWER TO MIDDLE 90S
ON TUESDAY. COMBINED WITH DEW POINTS IN THE 70S, HEAT INDEX VALUES
SHOULD EXCEED 100 DEGREES ACROSS MUCH OF OUR AREA. THE HIGHEST
VALUES WILL BE ALONG THE COASTAL SEA BREEZE, WHERE DEW POINT POOLING
IS EXPECTED. THIS WILL EQUATE TO HEAT INDEX VALUES PEAKING IN THE
105-110 DEGREE F RANGE. WE NEED HEAT INDICES OF 108 DEGREES F FOR AT
LEAST 2 HOURS TO PROMPT A HEAT ADVISORY. HOWEVER, THE HOURLY
FORECAST VALUES INDICATE THIS IS VERY BORDERLINE. ADDITIONALLY,
AFTERNOON CONVECTION WILL QUICKLY LOWER HEAT INDICES. SO WE CANNOT
RULE OUT HEAT ADVISORIES FOR A SHORT TIME PERIOD NEAR THE COAST.
AVIATION /18Z SATURDAY THROUGH THURSDAY/
20/18Z TAF DISCUSSION: A WEAK FRONT PUSHING SOUTH WILL HELP
FOCUS SHOWER AND STORM ACTIVITY ACROSS SE GA LATE AFTERNOON
THROUGH EARLY EVENING. WHILE THE MAJORITY OF THE STORMS ARE
EXPECTED TO REMAIN JUST SOUTH OF SAV, A PASSING STORM OR TWO
COULD BRING BRIEF RESTRICTIONS AND GUSTY ERRATIC WINDS TO THE
TERMINAL. FURTHER NORTH, DRY MID-LEVEL AIR WILL LIMIT STORM
CHANCES, WITH VFR PREVAILING AT CHS/JZI THIS AFTERNOON AND
EVENING. VFR THEN PREVAILS AT ALL TERMINALS OVERNIGHT INTO
SUNDAY.
EXTENDED AVIATION OUTLOOK: BRIEF FLIGHT RESTRICTIONS ARE POSSIBLE
WITH ANY SHOWERS AND THUNDERSTORMS.
MARINE
THROUGH TONIGHT: BREEZY POST-SEABREEZE WINDS NEARSHORE CONTINUE
THROUGH EARLY EVENING, WITH LIGHT WINDS PREVAILING TONIGHT. A
FEW STORMS COULD PUSH OFF THE GA COAST LATER TODAY, BRINGING
LOCALLY GUSTY/ERRATIC WINDS. OTHERWISE, SEAS SUBSIDE TO 1-2 FT
OVERNIGHT, OVERALL EXCELLENT MARINE CONDITIONS FOR THIS TIME OF
YEAR.
SUNDAY THROUGH THURSDAY: THE ONLY MARINE CONCERN IS THE
SYNOPTIC SETUP COULD CAUSE A SURGE OF SW WINDS TUESDAY AFTERNOON
AND EVENING. GUSTS COULD APPROACH 25 KTS AT TIMES, ESPECIALLY
FOR THE CHARLESTON COUNTY WATERS. BUT IT LOOKS VERY MARGINAL FOR
SMALL CRAFT ADVISORIES AT THIS TIME. OTHERWISE, THE REST OF THE
TIME PERIOD WILL CONSIST OF A TYPICAL SUMMERTIME WIND REGIME.
CLIMATE
RECORD HIGH MINIMUM TEMPERATURES:
JUNE 23:
KCHS: 78/2024
KSAV: 77/2017
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page