892
FXUS62 KCHS 040733
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
333 AM EDT SUN MAY 4 2025
SYNOPSIS
A COLD FRONT WILL LINGER NEARBY BEFORE SHIFTING OFFSHORE ON
MONDAY. THEREAFTER, HIGH PRESSURE WILL BUILD IN AGAIN FROM THE
WEST. ANOTHER COLD FRONT COULD IMPACT THE REGION LATER NEXT
WEEK.
NEAR TERM /THROUGH TONIGHT/
PREDAWN HOURS: CONVECTION CONTINUES TO PROGRESS INTO THE AREA.
THE INLAND ACTIVITY IS BEING DRIVEN BY AN OUTFLOW BOUNDARY AND
THE OVERALL STRENGTH OF THE SHOWERS AND STORMS IS QUITE WEAK AS
IT IS IN AN AREA WITH WEAK INSTABILITY. ALONG THE COAST AND THE
ADJACENT COASTAL WATERS, THIS ACTIVITY IS STRONGER AS IT IS
WITHIN A BELT OF MLCAPE THAT IS ON THE ORDER OF 1,000-1,500
J/KG. THE MAIN IMPACTS WILL BE BRIEF PERIODS OF HEAVY RAIN, AND
GUSTY WINDS MAINLY IMPACTING THE COAST AND THE COASTAL WATERS.
THIS ONGOING ACTIVITY WILL CONTINUE FOR THE NEXT COUPLE OF HOURS
BUT THE TREND SHOULD BE FOR THE BEST ENVIRONMENT TO SHIFT TO
THE EAST AND NORTHEAST WITH TIME. OVERALL, WE EXPECT MOST SHOWER
AND THUNDERSTORM ACTIVITY TO HAVE SHIFTED OFFSHORE BY AROUND OR
JUST AFTER SUNRISE.
TODAY: ALOFT, THE PROMINENT LOW WILL BE CENTERED ACROSS KY AND
TN AND WILL MAKE LITTLE IF ANY PROGRESS THROUGH THE DAY, PLACING
THE FORECAST AREA ON THE SOUTHEAST PERIPHERY AND WITHIN
SOUTHWEST FLOW. AT THE SURFACE, THE FRONT WILL START THE DAY
WEST OF I-95 AND IS EXPECTED TO MAKE GRADUAL EASTWARD PROGRESS
THROUGH THE DAY SUCH THAT IT IS ALIGNED ROUGHLY RIGHT ALONG THE
I-95 CORRIDOR BY SUNSET. THE MAIN FORECAST CHALLENGE REVOLVES
AROUND DETERMINING THE COVERAGE AND STRENGTH OF SHOWERS AND
THUNDERSTORMS JUST AHEAD OF THE FRONT THIS AFTERNOON. GIVEN THE
EXPECTED POSITION OF THE FRONT AND THE ARRIVAL OF DRIER AIR IN
THE LOW LEVELS, THE WESTERN PORTION OF THE FORECAST AREA VERY
LIKELY TO REMAIN DRY. THE BEST CHANCE FOR CONVECTION WILL BE
MAINLY ALONG AND EAST OF I-95. THE SUITE OF HI-RES MODEL
GUIDANCE IS NOT EXCITED ABOUT COVERAGE OR STRENGTH, FEATURING
JUST ISOLATED SHOWERS AND THUNDERSTORMS MAINLY FOR THE SC COAST
AND THE TRI-COUNTY REGION. MODEL SOUNDINGS DO SHOW FAIRLY WARM
TEMP PROFILES WITH HEIGHT POTENTIALLY LIMITING DESTABILIZATION.
HOWEVER, IF A FEW STORMS CAN GET GOING, THERE IS SOME DRY AIR IN
THE MID-LEVELS WHICH WILL YIELD SOME ENHANCED DCAPE. SO, THERE
WILL BE A LOW END SEVERE THREAT FOR HAIL AND DAMAGING WIND GUSTS
IN THE AREA ALONG AND EAST OF I-95. THE TIME FOR CONCERN WILL
BE FROM NOON INTO THE EARLY EVENING HOURS. TEMPERATURES ARE
FORECAST TO RISE INTO THE LOW 80S FOR MOST AREAS, WITH SOME MID
80S EXPECTED FOR SOUTHEAST GA.
TONIGHT: WHILE ISOLATED CONVECTION COULD LINGER ALONG OR NEAR
THE CHARLESTON COUNTY COAST THIS EVENING, THE OVERNIGHT PERIOD
SHOULD BE MOSTLY DRY WITH THE PASSAGE OF THE FRONT OFFSHORE.
TEMPERATURES ARE EXPECTED TO BE NOTICEABLY COOLER THAN THE LAST
FEW NIGHTS WITH LOW TO MID 50S INLAND AND MID TO UPPER 50S ALONG
THE COAST.
SHORT TERM /MONDAY THROUGH WEDNESDAY/
MONDAY: WITH CLOSED UPPER-LVL LOW SITUATED OVER THE BLUEGRASS
REGION AND A SECONDARY UPPER-LVL LOW LOCATED NEAR THE CALIFORNIA
COASTLINE, THIS OMEGA BLOCKING PATTERN WILL CONTINUE DOMINATE
THE CONUS. AT THE SURFACE, A COLD FRONT SHOULD PUSH OFFSHORE IN
THE LATE MORNING AND SKIES WILL QUICKLY CLEAR OUT THEREAFTER. IF
ANY SHOWERS AND THUNDERSTORMS DO LINGER IN THE MORNING, THEY
SHOULD REMAIN OFFSHORE. WEAK UPPER-LVL RIDGING WILL BEGIN TO
FILTER INTO THE FORECAST REGION THROUGHOUT THE DAY. THANKFULLY,
THE SUN WILL BREAK THROUGH AND STAY FOR THE MAJORITY OF THE DAY.
HOWEVER, DUE TO SOME POST-FROPA, HIGHS WILL ONLY CLIMB INTO THE
LOW TO MID 80S. COOLER TEMPERATURES ARE ALSO EXPECTED OVERNIGHT
WITH LOWS DIPPING DOWN INTO THE MID 50S INLAND AND LOW TO MID
60S ALONG THE COAST.
TUESDAY: THIS OMEGA BLOCKING PATTERN WILL BEGIN TO FINALLY
BREAK DOWN AS THE CLOSED UPPER-LVL LOW BEGINS TO MOVE SLIGHTLY
FURTHER AWAY. WEAK UPPER-LVL RIDGING WILL CONTINUE TO FILTER IN
ON TUESDAY AND ALLOW FOR A RAIN-FREE DAY. WITH SOME SURFACE
HEATING, HIGHS WILL CLIMB INTO MID TO UPPER 80S. CLOUDS WILL
BEGIN TO MOVE INTO THE REGION OVERNIGHT AND LOWS WILL ONLY DROP
INTO THE LOW 60S INLAND AND MID TO UPPER 60S ALONG THE COAST.
WEDNESDAY: AS YET ANOTHER CLOSED UPPER-LVL LOW APPROACHES FROM
THE WEST, CLOUDS WILL FULLY TAKE OVER AND MOISTURE WILL RETURN
TO THE REGION. A WEAK ASSOCIATED FRONT WILL POSSIBLY LINGER OVER
SOUTHEAST GEORGIA AND OFF THE COAST OF SOUTH CAROLINA
THROUGHOUT THE DAY ALLOWING FOR SOME SHOWERS AND THUNDERSTORMS
TO DEVELOP. THEREFORE, SLIGHT CHANCE POPS WERE MENTIONED IN THE
FORECAST. ANY RAINFALL SHOULD REMAIN LESS THAN 0.25". WITH
POSSIBLE SHOWERS AND THUNDERSTORMS, HIGHS WILL BE A TAD COOLER
THAN THE DAY BEFORE AND WILL JUST TIP INTO THE LOW TO MID 80S.
TEMPERATURES OVERNIGHT STAY WARM WITH LOWS IN THE LOW 60S INLAND
AND MID TO UPPER 60S CLOSER TO THE COAST.
LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/
AS THE CLOSED UPPER-LVL LOW EVENTUALLY MOVES OFF THE NEW
ENGLAND COASTLINE OVERHEAD, CHANCE FOR SHOWERS AND THUNDERSTORMS
CONTINUE THROUGH THE WEEKEND AS THIS OTHER UPPER-LVL LOW
CONTINUES TO APPROACH THE REGION AND A FRONT POSSIBLY LINGERS
NEARBY. TEMPERATURES WILL COOL TO AROUND NORMAL THROUGH THE
PERIOD.
AVIATION /08Z SUNDAY THROUGH THURSDAY/
KCHS AND KJZI: FOR THE NEXT FEW HOURS, SHOWERS AND A
THUNDERSTORM OR TWO WILL IMPACT THE TERMINALS. BRIEF PERIODS OF
HEAVY RAIN COULD YIELD BRIEF MVFR OR EVEN IFR CONDITIONS, BUT
OVERALL VFR WILL PREVAIL. THIS SHOWER ACTIVITY WILL MAXIMIZE
OVER THE NEXT 3-4 HOURS, BUT SHOULD DWINDLE BY AROUND 12Z.
LOOKING INTO THE MIDDAY AND AFTERNOON TIME PERIOD, ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE. IT IS
UNCLEAR JUST HOW MUCH COVERAGE THERE WILL BE AT THIS TIME, AND
IT IS ENTIRELY PLAUSIBLE THAT THERE IS LITTLE TO NO SHOWER AND
THUNDERSTORM COVERAGE AT ALL. FOR NOW, WE HAVE INTRODUCED A
PROB30 FOR TSRA BETWEEN 16-19Z. WINDS WILL LIKELY BE BREEZY
AGAIN, BUT NOT AS GUSTY AS SATURDAY.
KSAV: LIGHT RAIN WITH EMBEDDED HEAVIER SHOWERS WILL CONTINUE TO
MOVE THROUGH FOR THE NEXT 2-3 HOURS. CONDITIONS SHOULD MOSTLY
BE VFR, BUT THERE COULD BE BRIEF PERIODS OF MVFR CEILINGS OR
VISIBILITIES. WE SHOULD SEE THE RAIN COME TO AN END BY 12Z.
LOOKING AHEAD TO THE MIDDY AND AFTERNOON PERIOD, WE COULD SEE
ISOLATED SHOWERS AND THUNDERSTORMS, BUT CHANCES APPEAR TO LOW TO
INCLUDE IN THE TAF AT THIS POINT.
EXTENDED AVIATION OUTLOOK: WITH THE COLD FRONT OFFSHORE, VFR
CONDITIONS SHOULD RETURN AT CHS/JZI/SAV. ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS COULD POSSIBLY IMPACT ALL TERMINALS
EARLY WEDNESDAY MORNING AS A FRONT LINGERS ACROSS SOUTHEAST
GEORGIA AND JUST OFFSHORE THE SOUTH CAROLINA COAST.
MARINE
TODAY THROUGH TONIGHT: SOUTHWEST FLOW IS EXPECTED TO MOSTLY BE
IN THE 10-15 KNOT RANGE TODAY, WITH GUSTS UP TO AROUND 20 KNOTS
POSSIBLE. THE FRONT WILL SHIFT THROUGH THE WATERS OVERNIGHT
WHICH WILL TURN WINDS NORTHWESTERLY, THOUGH WITH SPEEDS
GENERALLY NO MORE THAN 10 KNOTS. SEAS ARE EXPECTED TO AVERAGE
3-4 FEET TODAY, THEN 2-3 FEET OVERNIGHT. THUNDERSTORMS WILL
LIKELY MOVE THROUGH PORTIONS OF THE WATERS THROUGH THE DAY AND
OVERNIGHT. THESE STORMS WILL BE CAPABLE OF PRODUCING STRONG WIND
GUSTS AND FREQUENT LIGHTNING.
MONDAY THROUGH FRIDAY: WITH THE COLD FRONT JUST OFFSHORE, HIGH
PRESSURE WILL BEGIN TO BUILD AND NORTHEASTERLY WINDS WILL TURN
SOUTH-SOUTHEASTERLY BY MONDAY AFTERNOON. WINDS WILL BRIEFLY
TURN NORTH-NORTHEASTERLY ON TUESDAY, BUT WILL QUICKLY SPIN BACK
AROUND TO THE SOUTHEAST BY TUESDAY NIGHT. WITH SOME ONSHORE
FLOW NEAR THE COAST, WAVES WILL BE A BIT CHOPPY CLOSE TO THE
BEACHES. MIGHT NOT BE THE BEST SURF CONDITIONS FOR THE NEXT
COUPLE DAYS. CONDITIONS SHOULD REMAIN BELOW SCAS CRITERIA
THROUGH THURSDAY NIGHT WITH SOUTHEASTERLY WINDS GENERALLY 10 TO
15 KTS AND SEAS 2 TO 3 FT. AS ANOTHER COLD FRONT MOVES THROUGH
ON FRIDAY, EASTERLY WINDS WILL SURGE AND SOME 6 FOOTERS WILL
BUILD INTO THE OUTER GEORGIA WATERS. THUS, A SMALL CRAFT
ADVISORY WILL LIKELY BE NEEDED BEGINNING ON FRIDAY AFTERNOON.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
NEAR TERM...BSH
SHORT TERM...DENNIS
LONG TERM...DENNIS
AVIATION...BSH/DENNIS
MARINE...BSH/DENNIS
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