965
FXUS62 KCHS 291815
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
215 PM EDT SAT AUG 29 2026
WHAT HAS CHANGED
ALL SECTIONS UPDATED.
KEY MESSAGES
- 1) UNSETTLED WEATHER WILL CONTINUE THROUGH THIS WEEKEND.
LOCALLY HEAVY RAINFALL IS POSSIBLE.
DISCUSSION
KEY MESSAGE 1: UNSETTLED WEATHER WILL CONTINUE THROUGH THIS WEEKEND.
LOCALLY HEAVY RAINFALL IS POSSIBLE.
REST OF TODAY: THE REGION IS CURRENTLY POSITIONED WITHIN AN AREA OF
TROUGHING ALOFT, SANDWICHED BY TWO AREAS OF HIGH PRESSURE, ONE OVER
WESTERN TEXAS AND THE OTHER OVER BERMUDA. AT THE SURFACE A
STATIONARY FRONT WAS ANALYZED BY WPC OVER THE SC MIDLANDS. BETWEEN
THE TROUGHING ALOFT AND THE FRONT IN THE VICINITY THE STAGE HAS BEEN
SET FOR SCATTERED TO NUMEROUS CONVECTION THIS AFTERNOON. HOWEVER,
THICK CLOUD COVER ACROSS THE ENTIRE FORECAST AREA FROM THIS MORNING
HAS LINGERED INTO THIS AFTERNOON. THESE CLOUDS WILL LIKELY LIMIT
CONVECTION THIS AFTERNOON, WITH STORMS RELYING ON OUTFLOW BOUNDARIES
FOR INITIATION. THE ENVIRONMENT ACROSS THE REGION IS VERY
MOIST, WITH THE KCHS 12Z RAOB SOUNDING SETTING A NEW SPC
CLIMATOLOGY DAILY MAXIMUM OF 2.31". HEAVY RAINFALL CANNOT BE
RULED OUT WITH ANY STORM THAT IS ABLE TO DEVELOP THIS AFTERNOON.
THERE IS A MINIMAL SEVERE RISK THIS AFTERNOON AS SPC
MESOANALYSIS ONLY DEPICTS AROUND 300-400 J/KG OF DCAPE ACROSS
THE REGION. HOWEVER, A STRONG WIND GUST CANNOT BE COMPLETELY
RULED OUT THIS TIME OF YEAR.
TONIGHT: CONVECTION IS EXPECTED WANE FAIRLY QUICKLY THIS
EVENING. AS INLAND AREAS COOL AND LOW-LEVEL WINDS BACK, A
CORRIDOR OF MODEST CONVERGENCE IS FORECAST TO DEVELOP ALONG
MAINLY THE LOWER SOUTH CAROLINA COAST FROM ROUGHLY MIDNIGHT
THROUGH DAYBREAK SUNDAY. WITH SUCH A WARM AND MOIST ATMOSPHERE
IN PLACE, IT WILL NOT TAKE MUCH TO INITIATE ADDITIONAL
SHOWERS/TSTMS DURING THE EARLY MORNING HOURS. THERE IS A
POTENTIAL FOR SOME CONVECTIVE TRAINING TO OCCUR WITHIN THE
PLUME OF PWATS >2" AND THE 29/00Z HREF ARE SHOWING SOME
ELEVATED PROBABILITIES FOR >1"/3-HR IN THE VICINITY OF DOWNTOWN
CHARLESTON. THIS WILL NEED TO BE MONITORED AS A QUICK INCH IN
DOWNTOWN CHARLESTON IS KNOWN TO CAUSE FLASH FLOODING.
SUNDAY: SURFACE HIGH PRESSURE WILL RE-ESTABLISH EARLY SUNDAY MORNING AFTER
THE STATIONARY FRONT DISSIPATES. DIURNAL HEATING WILL YIELD MODERATE
INSTABILITY, WITH SBCAPE VALUES 2500-3000 J/KG. HOWEVER, WEAK
ENVIRONMENTAL FLOW ALOFT WILL LIMIT STORM ORGANIZATION, KEEPING THE
OVERALL THREAT FOR SEVERE WEATHER LOW. CONVECTION WILL REMAIN
LARGELY MESOSCALE-DRIVEN, WITH THE SEA BREEZE BOUNDARY PRIMARILY
INITIATING ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS. THERE
REMAINS A THREAT FOR LOCALIZED HEAVY RAIN/FLOODING SUNDAY, BUT NOT
AS WIDESPREAD AS PREVIOUS DAYS' DUE TO THE ANTICIPATED LACK IN
COVERAGE. FORECAST SOUNDINGS REFLECT A CLASSIC HEAVY-RAINFALL
PROFILE WITH PWATS 2.1-2.2 INCHES AND WEAK STEERING ALOFT (~10 KT).
BECAUSE THESE STORMS WILL MOVE RELATIVELY SLOWLY, RAIN RATES
POSSIBLY EXCEEDING 1 TO 2 INCHES PER HOUR COULD DUMP HEAVY RAIN IN A
SHORT WINDOW. TO NOTE, HREF PROBABILITIES CURRENTLY ONLY SHOW A
COUPLE SPOTS WITH A 20-40% CHANCE OF 2+ INCHES OF RAIN. NONETHELESS,
MINOR FLOODING IS POSSIBLE IN LOW-LYING AND FLOOD-PRONE/URBAN
AREAS.
AVIATION /18Z SATURDAY THROUGH THURSDAY/
MVFR CIGS HAVE HELD STRONG AT KCHS/KJZI/KSAV THROUGH THE START
OF THE 18Z TAF PERIOD. CIGS ARE FORECAST TO LIFT TO VFR LEVELS
LATER THIS AFTERNOON, WITH SHOWERS AND THUNDERSTORMS IMPACTING
ALL TERMINALS. HOWEVER, THIS IS A VERY LOW CONFIDENCE FORECAST.
THE LINGERING MVFR CIGS WILL LIKELY LIMIT THE OVERALL COVERAGE
OF CONVECTION, SO THE LONGER MVFR CIGS LAST THE LESSER THE
THREAT FOR THUNDERSTORMS. SHOWERS/TSTORMS ARE FORECAST TO WANE
WITH NIGHTFALL, BUT ANOTHER ROUND OF PRECIPITATION IS POSSIBLE
LATE TONIGHT/EARLY SUNDAY MORNING AT KCHS/KJZI.
EXTENDED AVIATION OUTLOOK: BRIEF FLIGHT RESTRICTIONS ARE POSSIBLE
WITHIN SHOWERS AND THUNDERSTORMS, ESPECIALLY DURING THE
AFTERNOONS.
MARINE
THROUGH TONIGHT: ONSHORE WINDS WILL LINGER THROUGH TONIGHT WITH
DIRECTIONS NEAR THE BEACHES LIKELY BACKING MORE EAST TO
NORTHEAST LATE. SPEEDS WILL REMAIN LESS THAN 15 KT THROUGH
TONIGHT WITH SEAS 1-3 FT.
SUNDAY THROUGH THURSDAY: EXPECT BENIGN MARINE CONDITIONS OVERALL.
LIGHT AND VARIABLE PREVAILING FLOW WILL SHIFT ONSHORE EACH AFTERNOON
AS THE SEA BREEZE CIRCULATION DEVELOPS ALONG THE COAST.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
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