193
FXUS62 KCHS 181833
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
233 PM EDT MON MAY 18 2026
WHAT HAS CHANGED
ALL SECTIONS WERE UPDATED.
KEY MESSAGES
- 1) MINOR COASTAL FLOODING IS POSSIBLE ALONG COASTAL AREAS OF
CHARLESTON AND COLLETON COUNTIES WITH HIGH TIDE THIS EVENING
AND POSSIBLY TUESDAY EVENING.
- 2) RAIN CHANCES LIKELY TO INCREASE LATE IN THE WEEK, THOUGH
NO HAZARDOUS WEATHER IS ANTICIPATED AT THIS TIME.
DISCUSSION
KEY MESSAGE 1: MINOR COASTAL FLOODING IS POSSIBLE ALONG COASTAL
AREAS OF CHARLESTON AND COLLETON COUNTIES WITH HIGH TIDE THIS
EVENING AND POSSIBLY TUESDAY EVENING.
ASTRONOMICAL INFLUENCES ASSOCIATED WITH THE RECENT NEW MOON AND
LUNAR PERIGEE ALONG WITH A MODEST ONSHORE FLOW WILL CONTINUE TO
DRIVE ELEVATED TIDE LEVELS, POTENTIALLY LEADING TO MINOR COASTAL
FLOODING ALONG PARTS OF THE LOWER SOUTH CAROLINA COAST THIS EVENING.
THE LATEST FORECAST ADVERTISES A PEAK HIGH TIDE 7.0-7.2 FT MLLW IN
THE CHARLESTON HARBOR THIS EVENING AND 6.9-7.1 FT MLLW TUESDAY
EVENING. A COASTAL FLOOD ADVISORY FOR COASTAL COLLETON AND
CHARLESTON COUNTIES COULD BE NEEDED FOR THIS EVENING'S HIGH TIDE AND
POSSIBLY AGAIN TUESDAY EVENING, ALTHOUGH CONFIDENCE IN REACHING THE
7.0 FT MLLW MINOR FLOOD STAGE IS MUCH MORE UNCERTAIN BY THEN.
ASTRONOMICAL TIDE LEVELS THEN BEGIN TO FALL AND THE POTENTIAL FOR
MINOR COASTAL FLOODING WILL DIMINISH.
KEY MESSAGE 2: RAIN CHANCES LIKELY TO INCREASE LATE IN THE WEEK,
THOUGH NO HAZARDOUS WEATHER IS ANTICIPATED AT THIS TIME.
THE SYNOPTIC PATTERN IS FORECAST TO SHIFT SLIGHTLY DURING THE
LATTER HALF OF THE WEEK, BRINGING A MORE UNSETTLED WEATHER
REGIME TO THE REGION. WHILE FINER DETAILS REMAIN UNCERTAIN,
MOST GUIDANCE INDICATES SHORTWAVE ENERGY ROUNDING THE
NORTHWESTERN PERIPHERY OF AN UPPER RIDGE WEDNESDAY INTO FRIDAY.
AT THE SURFACE, A COLD FRONT IS EXPECTED TO DROP SOUTHEASTWARD
ACROSS THE GREAT APPALACHIAN VALLEY LATE WEDNESDAY BEFORE
POTENTIALLY STALLING ACROSS THE CAROLINAS AND LATER LIFTING
INTO THE NORTHEAST U.S. AS A WARM FRONT BY SATURDAY. THE
APPROACH OF THIS BOUNDARY WILL PROMOTE INCREASING MOISTURE AND
RAIN CHANCES ACROSS THE REGION. HOWEVER, THE EVENTUAL PLACEMENT
AND SOUTHWARD PROGRESSION OF THE FRONT WILL PLAY A KEY ROLE IN
DETERMINING WHERE AND HOW MUCH PRECIPITATION OCCURS. NOTABLY,
THE LATEST ENSEMBLE GUIDANCE INDICATES A 20-50% PROBABILITY OF
ACCUMULATED RAINFALL EXCEEDING ONE INCH, WITH THE HIGHEST
PROBABILITIES CURRENTLY FOCUSED INLAND.
IN TERMS OF SEVERE WEATHER POTENTIAL, THE LATEST SOLUTIONS
FAVOR THE DEEPER MOISTURE AND THUS GREATER INSTABILITY TO REMAIN
TO OUR NORTH. ADDITIONALLY, WEAK FORCING AND SHEAR WILL KEEP
THE POTENTIAL FOR SEVERE WEATHER LOW DURING THIS LATTER PORTION
OF THE WEEK.
AVIATION /18Z MONDAY THROUGH SATURDAY/
18/18Z TAF DISCUSSION:
KCHS/KJZI/KSAV: VFR. GUSTY WINDS WILL OCCUR WITH THE PASSAGE OF
THE SEA BREEZE THIS AFTERNOON. SHALLOW GROUND FOG WILL BE
POSSIBLE AGAIN AT ALL TERMINALS EARLY TUESDAY MORNING.
EXTENDED AVIATION OUTLOOK: THERE ARE NO HIGH CONFIDENCE
CONCERNS.
MARINE
THROUGH TONIGHT: THE SYNOPTIC FLOW REGIME WILL CHANGE LITTLE THROUGH
TONIGHT AS ATLANTIC HIGH PRESSURE REMAINS CENTERED WELL OFFSHORE. AN
EASTERLY FLOW REGIME WILL PREVAIL WITH EAST TO SOUTHEAST WINDS 15 KT
OR LESS PREVAILING. SOME LOCAL ENHANCEMENT COULD OCCUR ALONG THE
LAND/SEA INTERFACE AND CHARLESTON HARBOR THIS AFTERNOON WITH THE SEA
BREEZE. SEAS WILL AVERAGE 2-4 FT.
TUESDAY THROUGH SATURDAY: NO MARINE CONCERNS ARE EXPECTED. HIGH
PRESSURE TO THE EAST WILL DRIVE ONSHORE EAST-SOUTHEASTERLY FLOW EACH
DAY, WITH WIND SPEEDS MOSTLY TOPPING OUT IN THE 10-15 KNOT RANGE.
EACH AFTERNOON AND EVENING THERE COULD BE SOME LOCAL ENHANCEMENT
ALONG THE LAND/SEA INTERFACE WITH THE DIURNAL SEA BREEZE. SEAS
SHOULD AVERAGE 2-4 FEET THROUGH THE PERIOD.
RIP CURRENTS: INFLUENCES FROM THE NEW MOON CYCLE COMBINED WITH
PERSISTENT ONSHORE FLOW WILL PRODUCE AN ELEVATED RISK OF RIP
CURRENTS. A MODERATE RISK FOR RIP CURRENTS IS IN PLACE FOR ALL
BEACHES THROUGH TUESDAY.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
BRS
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