641
FXUS62 KCHS 021139
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
739 AM EDT SAT MAY 2 2026
WHAT HAS CHANGED
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 12Z TAF ISSUANCE.
KEY MESSAGES
- 1) A WIDESPREAD RAINFALL EVENT WILL OCCUR ACROSS THE SOUTH CAROLINA
LOWCOUNTRY AND SOUTHEAST GEORGIA TODAY.
- 2) MINOR COASTAL FLOODING POSSIBLE WITH HIGH TIDE THIS EVENING
ALONG THE LOWER SOUTH CAROLINA COAST.
DISCUSSION
KEY MESSAGE 1: A WIDESPREAD RAINFALL EVENT WILL OCCUR ACROSS THE
SOUTH CAROLINA LOWCOUNTRY AND SOUTHEAST GEORGIA TODAY.
LATEST GUIDANCE REMAINS PERSISTENT WITH CYCLOGENESIS OFF THE
SOUTH CAROLINA/GEORGIA COAST PRIOR TO DAYBREAK WHILE STRONG H5
VORT ENERGY SHIFTS OVER A FRONT ACROSS NORTHERN FLORIDA AND THE
NEARBY ATLANTIC. THE SETUP PRESENTS A FAVORABLE CASE FOR LIGHT
TO MODERATE RAIN TO DEVELOP AND/OR BECOME WIDESPREAD LOCALLY
WITH STRENGTHENING ISENTROPIC LIFT ACROSS THE REGION AND A
SOUTHWESTERLY LOW-LVL JET ADVECTING DEEP MOISTURE TOWARDS THE
SOUTHEAST COAST (PWATS IN THE 1.5 TO 1.75 INCH RANGE). GREATEST
PRECIP COVERAGE IS POISED TO SETUP ACROSS THE INTERIOR PRIOR TO
DAYBREAK, BEFORE GRADUALLY EXPANDING EASTWARD WITH STRONGEST
FORCING AND LARGEST MOISTURE SUPPLY. ALTHOUGH SFC INSTABILITY
WILL BE LACKING DUE TO WIDESPREAD CLOUD COVER AND COOLER TEMPS
DURING DAYLIGHT HOURS, SOME GUIDANCE INDICATES POCKETS OF MODEST
ELEVATED INSTABILITY SUPPORTIVE FOR A FEW THUNDERSTORMS.
CHANCES FOR A THUNDERSTORM APPEAR GREATEST ALONG THE IMMEDIATE
COASTAL AREAS OF SOUTHEAST SOUTH CAROLINA AND ACROSS SOUTHEAST
GEORGIA. THERE IS EVEN A NON-ZERO CASE FOR SOME ENHANCED
CONVECTION (STRONGER THUNDERSTORM) ACROSS FAR SOUTHERN AREAS OF
GEORGIA (MORE LIKELY SOUTH OF THE ALTAMAHA RIVER) CLOSER TO THE
FRONT AND SFC LOW/INFLECTION POINT PRIOR TO SHIFTING OFFSHORE
DURING LATE MORNING HOURS. RAIN CHANCES SHOULD BEGIN TO DIMINISH
QUICKLY FROM WEST TO EAST BY MID- AFTERNOON AS MID-UPPER LVL
FORCING PASS OFFSHORE AND LOW PRESSURE EXITS THE AREA. DRY
CONDITIONS SHOULD PREVAIL FOR ALL AREAS SATURDAY EVENING AND
LINGER INTO THE OVERNIGHT HOURS.
STORM TOTAL RAINFALL AMOUNTS OF 1-2" THROUGH EARLY EVENING
REMAIN ON TRACK. 01/13Z NBM PROBABILITIES ARE AS FOLLOWS:
* PROB FOR >1": 85-95% (HIGHEST INLAND)
* PROB FOR >2": 25-55% (HIGHEST FAR INTERIOR SOUTHEAST GEORGIA)
* PROB FOR >3": 5-20% (HIGHEST FAR INTERIOR SOUTHEAST GEORGIA)
THIS EVENT REPRESENTS MUCH NEEDED RAINFALL GIVEN THE CURRENT DROUGHT
SITUATION. HOWEVER, RAINFALL RATES ARE ANTICIPATED TO BE LOW AND
KEEP THE THREAT OF FLASH FLOODING VERY LOW ACROSS THE AREA. THERE
COULD STILL BE SOME MINOR FLOODING ISSUES IN LOW-LYING AND POOR
DRAINAGE AREAS ACROSS THE CHARLESTON AND SAVANNAH METRO AREAS AS
POCKETS OF PERIODIC MODERATE TO LOCALLY HEAVY RAIN MOVE THROUGH.
HOWEVER, THE GREATEST RISK SHOULD BE ACROSS SOUTHERN LOCATIONS.
KEY MESSAGE 2: MINOR COASTAL FLOODING POSSIBLE WITH HIGH TIDE THIS
EVENING ALONG THE LOWER SOUTH CAROLINA COAST.
ASTRONOMICAL TIDES HAVE BEGUN A SLOW DECREASE NOW THAT WE HAVE
PASSED THE FULL MOON, BUT NORTHERLY WINDS WILL MAINTAIN A
CONSIDERABLE POSITIVE TIDAL ANOMALY THROUGH THIS EVENING. WIND
DIRECTIONS MAY BECOME SLIGHTLY LESS FAVORABLE BY THE 9:30 PM HIGH
TIDE IN CHARLESTON HARBOR, BUT IT STILL SEEMS AS THOUGH A +1.1 FT
ANOMALY IS POSSIBLE, AND WE MIGHT BARELY REACH 7.0 FT MLLW.
AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
IFR CIGS HAVE STRUGGLED TO REACH THE CHS/JZI/SAV TERMINALS
EARLY THIS MORNING, BUT ARE EXPECTED TO PREVAIL BY AROUND 12Z,
THEN REMAIN IFR THROUGH AT LEAST 20Z TODAY. A FEW RUMBLES OF
THUNDER CAN NOT BE RULED OUT, MAINLY AT JZI AND SAV TERMINALS
THROUGH 16-17Z. LIGHT TO MODERATE SHOWERS SHOULD TAPER OFF BY
AROUND 20Z, BUT IFR CONDITIONS SHOULD GRADUALLY IMPROVE TO MVFR
AT ALL TERMINALS BETWEEN 20Z-00Z THIS AFTERNOON/EARLY EVENING.
VFR CONDITIONS ARE THEN EXPECTED TO ARRIVE MID EVENING AT ALL
TERMINALS.
EXTENDED AVIATION OUTLOOK: EXPECT IMPROVING CONDITIONS BY EARLY
SUNDAY. OTHERWISE, THERE ARE NO CONCERNS THROUGH WEDNESDAY.
MARINE
SOUTHERLY FLOW WILL STRENGTHEN LATE WEDNESDAY NIGHT INTO THURSDAY
AHEAD OF A COLD FRONT. GUIDANCE CURRENTLY INDICATES A PRETTY HIGH
LIKELIHOOD OF SMALL CRAFT ADVISORY WIND GUSTS AND SEAS IN MOST
WATERS OUTSIDE CHARLESTON HARBOR DURING THIS PERIOD.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
DPB/JRL
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page