697
FXUS62 KCHS 070704
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
304 AM EDT THU MAY 7 2026
WHAT HAS CHANGED
ALL SECTIONS AND KEY MESSAGES WERE UPDATED.
KEY MESSAGES
- 1) ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE TODAY.
- 2) UNSETTLED WEATHER RETURNS FRIDAY NIGHT AND LINGERS THROUGH EARLY
NEXT WEEK.
DISCUSSION
KEY MESSAGE 1: ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE TODAY.
HIGH PRESSURE EXTENDING ACROSS THE WESTERN ATLANTIC WILL PLACE A
MOIST SOUTH/SOUTHWEST FLOW ACROSS THE SOUTHEAST UNITED STATES IN
ADVANCE OF COLD FRONT APPROACHING THE REGION LATE DAY, DRIVEN BY A
LONGWAVE TROUGH ADVANCING ACROSS THE GREAT LAKES REGION TOWARD THE
MID-ATLANTIC/NORTHEAST COAST. PRIOR TO DAYBREAK, INSTABILITY WILL
REMAIN QUITE LOW, WHICH IS EVIDENT ON RECENT RADAR IMAGERY SHOWING
CONVECTION STRUGGLING TO MAKE EASTWARD PROGRESS ACROSS INLAND ZONES
AHEAD OF ENHANCED FORCING ARRIVING AFTER DAYBREAK. GUIDANCE SUGGESTS
THIS ACTIVITY TO BE THE FIRST OF TWO CONVECTIVE WAVES ENTERING
SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA TODAY, LIKELY THE
WEAKER OF THE TWO WHILE OCCURRING DURING PRE-DAWN HOURS.
THE KEY TO ISOLATED SEVERE WEATHER TODAY WILL CONTINUE TO FOCUS ON
THE ABILITY OF THE ATMOSPHERE TO DESTABILIZE PRIOR TO A SECOND WAVE
OF CONVECTION ARRIVING MID-LATE MORNING INTO EARLY AFTERNOON. THE
MAIN ISSUE CONTINUES TO REVOLVE AROUND LIMITED INSTABILITY DURING
TIMING OF ENHANCED DEEP-LAYER SHEAR AND FORCING ASSOCIATED WITH LOW-
LVL JETTING WHILE A STRONG H25 JET CORE PASSES WELL INLAND AND NORTH
OF THE LOCAL AREA. GUIDANCE CONTINUES TO SUPPORT DEEP MOISTURE
ADVECTION INTO THE AREA (PWATS ~2.0 INCHES/SFC DEWPTS IN LOWER 70S)
AS A SOUTH/SOUTHWEST FLOW PREVAILS IN THE WARM-SECTOR, SUPPORTING
EXPANDING SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE INTERIOR
AROUND OR SHORTLY AFTER DAYBREAK. HOWEVER, WIDESPREAD CLOUDS
ASSOCIATED WITH ONGOING SHOWERS/THUNDERSTORMS AND ISENTROPIC FORCING
COULD LIMIT INSTABILITY ACROSS PARTS OF SOUTHEAST SOUTH CAROLINA AND
SOUTHEAST GEORGIA, ESPECIALLY ACROSS NORTHERN AREAS WHERE MID-HIGH
CLOUDS ARE LIKELY TO REMAIN THROUGHOUT THE MORNING. HOWEVER,
GUIDANCE DOES CONTINUE TO SUPPORT AN AXIS OF MODEST INSTABILITY
(SBCAPE ~1500 J/KG) DEVELOPING ACROSS SOUTHEAST GEORGIA AND PERHAPS
INTO COASTAL PARTS OF SOUTHERN SOUTHEAST SOUTH CAROLINA MID-LATE
MORNING INTO EARLY AFTERNOON WHERE A FEW BREAKS IN CLOUD COVER AND
WARM AIR ADVECTION ALLOW FOR SFC TEMPS TO REACH THE MID-UPPER 80S.
SFC TEMPS ARE LIKELY TO BECOME WARMEST NEAR THE I-95 CORRIDOR IN
SOUTHEAST GEORGIA, POSSIBLY REACHING THE LOWER 90S BEFORE THE ONSET
ON SHOWER AND THUNDERSTORM ACTIVITY.
THE COMBINATION OF DEEP MOISTURE (PWATS 2.0 INCHES/SFC DEWPTS LOWER
70S) AND 0-6 KM BULK SHEAR (50-60 KT) SUPPORTS AN ISOLATED SEVERE
WEATHER THREAT, DEPENDENT ON SFC HEATING/INSTABILITY REALIZED PRIOR
TO CONVECTION ARRIVING MID-LATE MORNING INTO EARLY AFTERNOON.
MOSTLY UNIDIRECTIONAL WIND PROFILES DEPICTED ON SOUNDINGS WITH
MODEST DIRECTIONAL CHANGE IN H85-H5 CROSSOVER WINDS ALONG WITH LOW-
LVL LAPSE RATES AROUND 6.5-7 C/KM SUPPORT PRIMARILY A DAMAGING WIND
THREAT FOR A FEW THUNDERSTORMS THAT BECOME STRONG/SEVERE WITHIN
CLUSTERS AND/OR SMALL LINEAR SEGMENTS. HOWEVER, THERE REMAINS A NON-
ZERO RISK FOR A BRIEF TORNADO ACROSS SOUTHEAST GEORGIA (MAINLY SOUTH
OF I-16) SHOULD AMPLE INSTABILITY DEVELOP PRIOR TO THE ONSET OF
CONVECTION AHEAD OF A SEA BREEZE PROMOTING A BACKING WIND COMPONENT
NEAR THE SFC. THE BULK OF THUNDERSTORM ACTIVITY SHOULD REMAIN SUB-
SEVERE TODAY, BUT STILL CAPABLE OF PRODUCING BRIEF MODERATE-HEAVY
RAINS AND PERHAPS MINOR FLOODING WITHIN A DEEP MOISTURE ENVIRONMENT,
ESPECIALLY IF THE PROGRESSION OF THE ARRIVING COLD FRONT SLOWS WHILE
PASSING ACROSS THE AREA LATE DAY/EARLY EVENING. THE STORM PREDICTION
CENTER CONTINUES TO PLACE A MARGINAL RISK (1/5) FOR SEVERE WEATHER
ACROSS THE ENTIRE AREA TODAY.
KEY MESSAGE 2: UNSETTLED WEATHER RETURNS FRIDAY NIGHT AND LINGERS
THROUGH EARLY NEXT WEEK.
DRY HIGH PRESSURE WILL BRIEFLY REBUILD ON FRIDAY, THEN THE FRONT
WILL LIFT BACK NORTH AND STALL OVER THE AREA FRIDAY NIGHT THROUGH
SUNDAY. A SERIES OF UPPER LEVEL SHORTWAVES WILL RIPPLE THROUGH THE
SOUTHEAST DURING THIS PERIOD. MEANWHILE, PWATS APPROACHING 1.8"
EXPECTED TO ADVECT INTO THE AREA SATURDAY THROUGH SUNDAY, PROVIDING
AMPLE MOISTURE FOR SHOWER DEVELOPMENT. POCKETS OF SURFACE-BASED
INSTABILITY WILL SUPPORT ISOLATED THUNDERSTORMS, PARTICULARLY DURING
THE AFTERNOON HOURS ACROSS COASTAL SOUTHEAST GA. TOTAL PRECIPITATION
FRIDAY NIGHT THROUGH SUNDAY EXPECTED TO RANGE FROM 0.75"-1.25",
THOUGH A FEW LOCATIONS COULD SEE AMOUNTS IN EXCESS OF 1.5". RAINFALL
AMOUNT AND INTENSITY NOT CURRENTLY EXPECTED TO RESULT IN A
SIGNIFICANT FLOODING THREAT.
A STRONG COLD FRONT WILL SWEEP THROUGH MONDAY AFTERNOON, BRINGING
NUMEROUS SHOWERS AND A FEW THUNDERSTORMS. GUIDANCE INDICATES THE
POTENTIAL FOR MODERATE SHEAR AND INSTABILITY PRECEDING THE FRONT, SO
AN ISOLATED SEVERE THUNDERSTORM WITH DAMAGING WINDS IS POSSIBLE.
AVIATION /06Z THURSDAY THROUGH MONDAY/
CONDITIONS SHOULD REMAIN VFR AT CHS/JZI/SAV TERMINALS THROUGH
DAYBREAK TODAY, BUT LIGHT SHOWER ACTIVITY SHOULD ARRIVE SHORTLY
THEREAFTER BEFORE THE ONSET OF MORE SHOWER AND/OR THUNDERSTORMS MID-
LATE MORNING INTO EARLY AFTERNOON. EXPECT BOUTS OF MVFR OR LOWER
CIGS ALONG WITH GUSTY WINDS GENERALLY IN THE 20-25 KT RANGE, HIGHEST
DURING DIRECT IMPACTS ASSOCIATED WITH CONVECTION. GREATEST SHOWER
AND THUNDERSTORM TIMING SHOULD OCCUR BETWEEN 14-18Z TODAY, WITH THE
RISK FOR A FEW STRONGER THUNDERSTORMS, MAINLY AT THE SAV TERMINAL
LATE MORNING INTO EARLY AFTERNOON. PERIODS OF MVFR CONDITIONS LIKELY
CONTINUE AT ALL TERMINALS MID-LATE AFTERNOON INTO EARLY EVENING
PRIOR TO A COLD FRONT PUSHING THROUGH THE AREA TONIGHT. VFR
CONDITIONS SHOULD THEN RETURN BY AROUND 02-04Z FRIDAY AT ALL
TERMINALS AS WINDS TURN MORE WESTERLY AND HIGH PRESSURE BUILDS
BEHIND THE FRONT.
EXTENDED AVIATION OUTLOOK: OCCASIONAL FLIGHT RESTRICTIONS SATURDAY
THROUGH MONDAY AS A STALLED FRONT BRINGS SHOWERS AND THUNDERSTORMS.
MARINE
TODAY AND TONIGHT: A SOMEWHAT ENHANCED PRESSURE GRADIENT ACROSS
LOCAL WATERS WILL SLOWLY WEAKEN IN ADVANCE OF PRE-FRONTAL CONVECTION
LATE MORNING AND AFTERNOON. SOUTHERLY WINDS CONTINUE TO GUST UP TO
20-25 KT ACROSS NEARSHORE SOUTH CAROLINA WATERS AND TO 25-30 KT
ACROSS OFFSHORE WATERS WITH SEAS AS LARGE AS 4-6 FT (LARGEST BEYOND
20 NM FROM THE COAST ACROSS SOUTH CAROLINA WATERS). SMALL CRAFT
ADVISORIES REMAIN IN EFFECT FOR NEARSHORE SOUTH CAROLINA WATERS AND
OFFSHORE GEORGIA WATERS THROUGH 10 AM, AND COULD NEED TO BE EXTENDED
IN TIME ACROSS WATERS OFF THE CHARLESTON COUNTY COAST DEPENDING ON
OVERALL CONVECTIVE INTERACTION WITH ARRIVING SHOWERS AND
THUNDERSTORMS TODAY. A COLD FRONT ARRIVES ACROSS THE AREA THIS
EVENING, LIKELY PASSING OFFSHORE ACROSS ALL WATERS OVERNIGHT.
ALTHOUGH WINDS COULD BRIEFLY SURGE POST FROPA, COLD AIR ADVECTION
DOES NOT APPEAR STRONG ENOUGH TO SUPPORT WINDS HIGHER THAN 20 KT
ACROSS LOCAL WATERS.
A RELATIVELY STRONG NORTHERLY FLOW WILL DEVELOP MONDAY NIGHT INTO
TUESDAY BEHIND ANOTHER COLD FRONT AS HIGH PRESSURE BUILDS IN. SMALL
CRAFT ADVISORIES MAY BE NEEDED FOR MOST WATERS OUTSIDE CHARLESTON
HARBOR DUE TO FREQUENT 25 KT WIND GUSTS.
RIP CURRENTS: ENHANCED WINDS ALONG THE LOWER SOUTH CAROLINA COAST
COUPLED WITH BUILDING 2-4 FT SWELL SUPPORTS A MODERATE RISK FOR RIP
CURRENTS ALONG THE CHARLESTON COUNTY BEACHES FOR TODAY.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR AMZ360-
362-384.
DPB/JRL
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