494
FXUS62 KCHS 191503
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1103 AM EDT FRI APR 19 2024
SYNOPSIS
A SLOW MOVING FRONT WILL BRING UNSETTLED WEATHER TO THE REGION
TODAY THROUGH EARLY NEXT WEEK. HIGH PRESSURE WILL THEN RETURN
AND PREVAIL INTO THE MIDDLE OF NEXT WEEK.
NEAR TERM /THROUGH TONIGHT/
LATE MORNING UPDATE: POP TRENDS STILL ON TRACK WITH THE MIDLANDS
CONVECTION CONTINUING TO DISSIPATE AS IT MOVES EAST.
CONSIDERABLE MORNING CLOUDINESS ACROSS SOUTHEAST SC IS LIMITING
BOUNDARY LAYER DESTABILIZATION. THE BRUNT OF THIS CLOUD COVER
SHOULD DISSIPATE BY EARLY AFTERNOON AS NVA AND DOWNSLOPE FLOW
SET UP. ADJUSTED TEMPERATURE TRENDS TO DELAY THE STRONGEST
HEATING UNTIL AFTER THE CLOUDS CLEAR OUT.
PREVIOUS DISCUSSION...
TODAY: H5 SHORTWAVE ENERGY WILL TRAVERSE THE LOCAL AREA EARLY THIS
MORNING, ATTEMPTING TO PRODUCE A FEW SHOWERS BEFORE REACHING
THE COAST BY LATE MORNING. MODEL SOUNDINGS CONTINUE TO INDICATE
A FAIRLY LARGE AMOUNT OF LOW-MID LEVEL DRY AIR, SUGGESTING
ACTIVITY REMAINING QUITE LIMITED DURING THE NEXT COUPLE HOURS.
HEADING INTO THE LATE MORNING HOURS, CONDITIONS REMAIN DRY WITH
A WEST-NORTHWEST DOWNSLOPE WIND IN PLACE ALOFT AND SFC HIGH
PRESSURE PREVAILING ACROSS THE SOUTHEAST FOR MUCH OF THE DAY.
LATEST GUIDANCE HAS TAKEN A STEP BACK IN REGARDS TO PRECIP
POTENTIAL LOCALLY, ESPECIALLY IN REGARDS TO STRONGER THUNDERSTORM
POTENTIAL THIS AFTERNOON. MUCH OF THE CONVECTION ANTICIPATED
LOCALLY TODAY SHOULD BE ASSOCIATED WITH A SEABREEZE CIRCULATION
TAKING SHAPE BY EARLY AFTERNOON, THEN GRADUALLY PUSHING INLAND
THROUGH MID-LATE AFTERNOON. WIND FIELDS ARE NOT ALL THAT IMPRESSIVE
AS THIS OCCURS AND THE BULK OF LARGE SCALE DYNAMIC FORCING
REMAINS WELL DISPLACED TO THE NORTHWEST CLOSER TO A SFC COLD
FRONT MAKING WAY ACROSS THE MIDLANDS LATE DAY. HOWEVER, AMPLE
SFC HEATING WILL TAKE PLACE AND THE DOWNSLOPE WIND ALOFT WILL
ALSO SUPPORT WARMER TEMPS IN ADVANCE OF THE FRONT DURING THE
DAY. HIGH TEMPS IN THE UPPER 80S TO AROUND 90 DEGREES AWAY FROM
THE COAST ALONG WITH SFC DEWPTS IN THE LOW-MID 60S SUPPORT
MODEST INABILITY AS CONVECTION INITIATES AND MAKES A GRADUALLY
PUSH INLAND, BUT THUNDERSTORMS WILL LIKELY REMAIN PULSE TYPE IN
NATURE AND SUB-SEVERE WITH A LACK OF STRONGER FORCING PRESENT.
THE BULK OF PRECIP COVERAGE SHOULD OCCUR ACROSS SOUTHEAST SOUTH
CAROLINA, WITH PEAK COVERAGE OCCURRING LATE AFTERNOON ACROSS FAR
INLAND AREAS.
TONIGHT: CONVECTION EXPERIENCED DURING LATE AFTERNOON HOURS WILL
LIKELY WANE OR DIMINISH EARLY EVENING DUE TO THE LOSS OF DIURNAL
HEATING. THE FIRST HALF OF THE NIGHT WILL LIKELY REMAIN DRY ACROSS
ALL AREAS WHILE WEAK HIGH PRESSURE LINGERS ACROSS THE AREA AHEAD OF
A COLD FRONT SLOWLY APPROACHING TOWARD NORTHWEST TIER COUNTIES OF
SOUTHEAST SOUTH CAROLINA. THE FLOW ALOFT REMAINS ZONAL, SUGGESTING
THE FRONT WILL STRUGGLE TO REACH THE LOCAL AREA AFTER MIDNIGHT, BUT
COULD PRODUCE A FEW SHOWERS/THUNDERSTORMS ACROSS NORTHERN PARTS OF
BERKELEY AND CHARLESTON COUNTIES BEFORE DAYBREAK. GIVEN THE TIMING
OF THE FRONT LATE NIGHT AND THE LIKELIHOOD OF IT REMAINING JUST TO
THE NORTH WHILE SLIDING OFFSHORE INDICATES THE THREAT FOR STRONGER
THUNDERSTORMS TO BE LOW. LOW TEMPS SHOULD REMAIN MILD WITH A LIGHT
SOUTH-SOUTHWEST WIND IN PLACE UNDER CLOUDS, GENERALLY IN THE MID-
UPPER 60S.
SHORT TERM /SATURDAY THROUGH MONDAY/
A SLOW MOVING COLD FRONT WILL LINGER OVER THE REGION ON SATURDAY,
WITH SOME SOUTHWARD PUSH LATER IN THE DAY AND OVERNIGHT. THE MORNING
HOURS SHOULD BE DRY THEN THE POTENTIAL FOR THUNDERSTORMS WILL
INCREASE AS WE MOVE LATER INTO THE AFTERNOON AND EVENING, THOUGH
COVERAGE IS STILL A BIT UNCERTAIN. SHEAR IS ONLY AROUND 20 KNOTS
WHEN INSTABILITY IS MAXIMIZED, SO OVERALL SEVERE THREAT IS LOW BUT A
STRONGER STORM CANNOT BE RULED OUT. OTHERWISE, HIGH TEMPERATURES
CREEP BACK UP INTO THE UPPER 80S/AROUND 90 AWAY FROM THE IMMEDIATE
COAST. LOWS SATURDAY NIGHT WILL BE IN THE 60S.
THE AFOREMENTIONED FRONT WILL STILL BE IN THE VICINITY SUNDAY
MORNING, LIKELY EXTENDING FROM OFF THE SC COAST DOWN INTO SOUTHEAST
GA, BEFORE SINKING FURTHER SOUTH WITH TIME. BETTER FORCING WILL
ARRIVE AS SHORTWAVE ENERGY PASSES ACROSS THE REGION WHICH SHOULD
LEAD TO AN UPTICK IN PRECIP COVERAGE. POPS PEAK 60-80%. THUNDER
POTENTIAL LOOKS TO BE LIMITED CLOSER TO THE COAST AND ACROSS
SOUTHEAST GA. TEMPERATURES WILL BE TRICKY GIVEN MUCH WILL DEPEND ON
POSITIONING OF THE FRONT, BUT OVERALL IT WILL BE NOTABLY COOLER THAN
PREVIOUS DAYS ESPECIALLY INLAND AND IN NORTHERN AREAS. HIGHS
GENERALLY SPAN THE 70S, WITH AROUND 80 NEAR THE ALTAMAHA AHEAD OF
THE FRONT. HIGHEST RAIN CHANCES TRANSITION OFFSHORE SUNDAY NIGHT.
LOW TEMPERATURES WILL BE IN THE 50S.
THE FRONT WILL BE WELL TO THE EAST ON MONDAY WITH HIGH PRESSURE
INLAND. MAIN UPPER WAVE SWINGS THROUGH LATER IN THE DAY WHICH COULD
LEAD TO ADDITIONAL SHOWER DEVELOPMENT ESPECIALLY ALONG THE COAST
WHERE DEEPER MOISTURE RESIDES. HIGH TEMPERATURES TOP OUT IN THE MID
TO UPPER 60S.
LONG TERM /MONDAY NIGHT THROUGH THURSDAY/
HIGH PRESSURE WILL PREVAIL INTO MIDWEEK, BEFORE A COLD FRONT
POSSIBLY PASSES THROUGH WEDNESDAY NIGHT/EARLY THURSDAY. THERE
DOESN'T APPEAR TO BE A LOT OF MOISTURE TO WORK WITH SO A DRY
FORECAST WAS MAINTAINED FOR NOW.
AVIATION /15Z FRIDAY THROUGH TUESDAY/
VFR CONDITIONS WILL PREVAIL AT CHS/JZI/SAV TERMINALS THROUGH 12Z
SATURDAY. THE RISK FOR A SHOWER/THUNDERSTORM AT CHS/JZI FRIDAY
AFTERNOON REMAINS TOO LOW TO INCLUDE AT THE TERMINALS AT THIS
TIME, BUT ACTIVITY COULD APPROACH CHS/JZI TERMINALS FOR A FEW
HOURS EARLY AFTERNOON AS A SEABREEZE CIRCULATION SHIFTS INLAND.
EXTENDED AVIATION OUTLOOK: A SLOW MOVING FRONT COULD BRING
OCCASIONAL FLIGHT RESTRICTIONS LATE SATURDAY THROUGH MONDAY.
MARINE
TODAY AND TONIGHT: HIGH PRESSURE WILL REMAIN THE DOMINANT WEATHER
FEATURE ACROSS LOCAL WATERS INTO EARLY NIGHT BEFORE A COLD FRONT
APPROACHES FROM THE NORTHWEST, EVENTUALLY SHIFTING OFFSHORE AFTER
MIDNIGHT NEAR OR JUST NORTH OF THE AREA. CONDITIONS WILL REMAIN
QUIET THROUGH THE DAY, WITH SOUTHWEST WINDS AROUND 10 KT OR LESS
EARLY MORNING TURNING MORE SOUTH AND GUSTING TO 10-15 KT IN THE
AFTERNOON AS A SEABREEZE DEVELOPS, THEN PUSHES INLAND. EVEN WITH THE
FRONT APPROACHING LATE TONIGHT, SFC WINDS SHOULD TIP BACK TO THE
SOUTH-SOUTHWEST DURING THE FIRST HALF OF THE NIGHT AND SHOW SIGNS OF
DECREASING. THE PRESSURE GRADIENT WILL REMAIN FAIRLY WEAK FOR MUCH
OF THE NIGHT, BUT THERE COULD BE A SLIGHT UPTICK IN SOUTHWEST WINDS
LATE (AROUND 15 KT) AS GRADIENT EVENTUALLY BECOMES STRONGER
APPROACHING DAYBREAK. SEAS WILL RANGE BETWEEN 2-3 FT, BUT SHOULD
GRADUALLY BUILD OVERNIGHT WITH 4 FT SEAS POSSIBLE ACROSS OFFSHORE
GEORGIA WATERS LATE.
SATURDAY THROUGH WEDNESDAY: SOUTH TO SOUTHWEST WINDS WILL PERSIST
THROUGH SATURDAY, BEFORE A SLOW MOVING COLD FRONT SINKS SOUTH
THROUGH THE WATERS LATER IN THE WEEKEND. MAIN TIME PERIOD OF CONCERN
WILL BE SUNDAY NIGHT THROUGH MONDAY WHEN WINDS PEAK IN THE 15-20 KT
RANGE BEHIND THE FRONT. A FEW GUSTS TO 25 KNOTS WILL BE POSSIBLE
OVER PORTIONS OF THE WATERS. WINDS EASE ON TUESDAY WITH NO
ADDITIONAL CONCERNS THROUGH WEDNESDAY.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
NEAR TERM...DPB/JRL
SHORT TERM...ETM
LONG TERM...ETM
AVIATION...DPB/ETM
MARINE...DPB/ETM
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