209
FXUS62 KCHS 010626
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
226 AM EDT MON JUN 1 2026
WHAT HAS CHANGED
ALL SECTIONS HAVE BEEN UPDATED.
KEY MESSAGES
- 1) LOCALLY HEAVY RAINFALL WILL REMAIN A THREAT FOR PORTIONS
OF SOUTHEAST GEORGIA AND SOUTHEAST SOUTH CAROLINA THROUGH
TUESDAY.
- 2) MINOR COASTAL FLOODING IS POSSIBLE ALONG THE CHARLESTON
AND COLLETON COUNTY COASTLINE WITH THE TUESDAY EVENING HIGH
TIDE.
DISCUSSION
KEY MESSAGE 1: LOCALLY HEAVY RAINFALL WILL REMAIN A THREAT FOR
PORTIONS OF SOUTHEAST GEORGIA AND SOUTHEAST SOUTH CAROLINA
THROUGH TUESDAY.
THROUGH TONIGHT: THE MAIN CONCERN FOR LOCALLY HEAVY RAINFALL
AND PERHAPS AN ISOLATED FLASH FLOOD THREAT WILL COME PRIMARILY
DURING THE EARLY MORNING HOURS. SURFACE ANALYSIS SHOWS A SURFACE
LOW TAKING SHAPE JUST OFF THE GA/SC COAST WHICH WILL THEN
GRADUALLY TRACK TO THE EAST THROUGH DAYBREAK. AS IT DOES, BANDS
OF CONVERGENCE WILL FEED BACK INTO THE COAST WITHIN A VERY MOIST
ENVIRONMENT DEFINED BY PRECIPITABLE WATER VALUES IN EXCESS OF 2
INCHES. HI-RES MODEL GUIDANCE HAS DISPLAYED SOME RUN-TO-RUN
INCONSISTENCY, BUT STILL SEEMS TO FAVOR THE SC COAST AND
SPECIFICALLY THE CHARLESTON COUNTY COAST FOR THE HEAVIEST RAIN
THROUGH SUNRISE. STORM MOTION IS QUITE SLOW AND WHEN COMBINED
WITH WARM CLOUD PROCESSES, RAINFALL EFFICIENCY IS QUITE HIGH.
THE MAIN CONCERN WILL BE FOR URBANIZED AREAS ALONG THE SC COAST,
SPECIFICALLY BEAUFORT AND CHARLESTON. THE THREAT FOR LOCALLY
HEAVY RAINFALL AND FLOODING SHOULD PERSIST THROUGH DAYBREAK AND
THEN COME TO AN END AS THE SURFACE LOW PULLS AWAY TO THE EAST.
FOR THE REST OF THE DAY, GUIDANCE WOULD SUGGEST THAT THERE WON'T
BE TOO MUCH CONVECTIVE COVERAGE AS THE FLOW TURNS OFFSHORE. THE
NEXT BEST CHANCE OF CONVECTION WILL COME DURING THE LATE
EVENING HOURS AS UPSTREAM THUNDERSTORMS ALONG THE COLD FRONT
APPROACHING FROM THE NORTH SHIFT INTO THE AREA. THESE STORMS
SHOULD HAVE ENOUGH MOTION TO PREVENT MUCH OF A FLOOD THREAT.
TUESDAY: THE COLD FRONT SHOULD START THE DAY HAVING CLEARED
SOUTHEAST SC AND CONTINUE TO SINK SOUTHWARD. THIS SHOULD PUT THE
FOCUS FOR AFTERNOON CONVECTIVE COVERAGE ACROSS SOUTHEAST
GEORGIA. FORTUNATELY THIS KEEPS MOST OF THE FORECAST AREA DRY,
BUT WE WILL HAVE TO WATCH THE PROGRESSION OF THE FRONT WITH TIME
AND CONTINUE TO ASSESS THE HEAVY RAIN POTENTIAL ACROSS
SOUTHEAST GEORGIA.
KEY MESSAGE 2: MINOR COASTAL FLOODING IS POSSIBLE ALONG THE
CHARLESTON AND COLLETON COUNTY COASTLINE WITH THE TUESDAY
EVENING HIGH TIDE.
A STRONG SURGE OF NORTHEAST FLOW WILL OCCUR ALONG THE SOUTHEAST
SC COAST ON TUESDAY BEHIND A PASSING COLD FRONT. THIS NORTHEAST
FLOW WILL PRODUCE A SURGE IN TIDE LEVELS, ESPECIALLY AROUND THE
TIME OF THE TUESDAY EVENING HIGH TIDE. THE ASTRONOMICAL TIDE
LEVEL IS 5.5 FT MLLW, SO IT WOULD REQUIRE A RATHER ANOMALOUS 1.5
FT DEPARTURE TO REACH THE MINOR COASTAL FLOOD THRESHOLD OF 7 FT
MLLW. FOR CONTEXT, HISTORICAL ANALYSIS SHOWS THAT A DEPARTURE OF
1.5 FT OR HIGHER HAS ONLY OCCURRED WITH ~7% OF ALL MINOR COASTAL
FLOOD EVENTS ON RECORD. STILL, MINOR COASTAL FLOODING IS
POSSIBLE AND A COASTAL FLOOD ADVISORY COULD BE NEEDED.
AVIATION /06Z MONDAY THROUGH FRIDAY/
KCHS AND KJZI: THE 06Z TAF PERIOD BEGINS WITH WIDESPREAD
SHOWERS AND IFR CONDITIONS. THIS WILL CONTINUE THROUGH AROUND
DAYBREAK WITH PERIODS OF HEAVIER SHOWERS POSSIBLE PRODUCING
LOWER VISIBILITIES. RAINFALL SHOULD COME TO AN END BY AROUND
SUNRISE AS AN AREA OF LOW PRESSURE OFFSHORE SHIFTS AWAY TO THE
EAST. IFR CEILINGS WILL PERSIST THROUGH ABOUT MID MORNING, THEN
LIFT TO MVFR THROUGH AROUND MIDDAY AND THEN RETURN TO VFR FOR
THE AFTERNOON. THERE COULD BE ISOLATED TO SCATTERED SHOWERS AND
STORMS THAT DEVELOP ALONG THE IMMEDIATE COAST IN THE AFTERNOON,
BUT CONFIDENCE IN DIRECT IMPACTS IS QUITE LOW AT THIS POINT.
KSAV: THE 06Z TAF PERIOD BEGINS WITH IFR CEILINGS AND SHOWERS
STILL IN THE VICINITY. THESE SHOWERS WILL COME TO AN END SOON
AND THEN THE MAIN FORECAST ISSUE WILL BE IFR CEILINGS THROUGH
ABOUT MID MORNING. CEILINGS SHOULD LIFT BACK TO MVFR AND THEN
BACK TO VFR BY AROUND MIDDAY THROUGH THE AFTERNOON. THERE COULD
BE ISOLATED TO SCATTERED SHOWERS AND STORMS THAT DEVELOP ALONG
THE IMMEDIATE COAST IN THE AFTERNOON, BUT CONFIDENCE IN DIRECT
IMPACTS IS QUITE LOW AT THIS POINT.
EXTENDED AVIATION OUTLOOK: PERIODIC FLIGHT RESTRICTIONS ARE
POSSIBLE THROUGH TUESDAY DUE TO SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS. PATCHY OVERNIGHT FOG AND/OR LOW STRATUS ARE ALSO
POSSIBLE.
MARINE
TODAY THROUGH FRIDAY: NO SIGNIFICANT CONCERNS THROUGH MONDAY
NIGHT. THEN ON TUESDAY A SURGE OF NORTHEAST FLOW WILL SPREAD
ACROSS THE LOCAL WATERS, PEAKING TUESDAY NIGHT. THIS WILL BRING
SOLID SMALL CRAFT ADVISORY CONDITIONS TO ALL WATERS (OUTSIDE
CHARLESTON HARBOR) WITH FREQUENT GUSTS. FURTHERMORE, GUIDANCE
SUGGESTS THERE IS A WINDOW OF TIME EARLY WEDNESDAY MORNING WHEN
GALE FORCE GUSTS WILL BE POSSIBLE AS WELL. NORTHEAST WINDS WILL
REMAIN ELEVATED WEDNESDAY BEFORE TAPERING OFF INTO THURSDAY.
OVERALL, SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED FOR A TIME
PERIOD FROM TUESDAY MORNING THROUGH THURSDAY MORNING FOR BOTH
WINDS AND SEAS.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
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