712
FXUS62 KCAE 021441
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1041 AM EDT FRI MAY 2 2025
SYNOPSIS
SCATTERED SHOWERS AND STORMS TODAY AHEAD OF AN APPROACHING COLD
FRONT. SHOWERS CONTINUE SATURDAY WITH MORE WIDESPREAD RAINFALL
LATE SATURDAY AND SUNDAY AS THE FRONT MOVES THROUGH THE AREA.
SOME SHOWERS REMAIN POSSIBLE INTO MONDAY, BUT THEN DRIER, COOLER
WEATHER RETURN FOR THE MIDDLE OF NEXT WEEK.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGE(S):
- WARM AND UNSETTLED TODAY WITH SCATTERED SHOWERS-STORMS THIS
AFTERNOON AND EVENING.
THE FORECAST FOR TODAY REMAINS LARGELY ON TRACK AS THE MAIN
UPPER TROUGH CONTINUES TO TRAVERSE THE SOUTHERN PLAINS AND A
SHORTWAVE IS SEEN DRIVING SOME CONVECTION INTO ARKANSAS AND WESTERN
TENNESSEE WHILE HIGH PRESSURE REMAINS OFF SHORE. THERE IS ALSO
AN AREA OF SHOWERS AND A COUPLE WEAK STORMS TOWARD THE UPSTATE
OF SC. CONTINUED SOUTHWEST FLOW HAS ALREADY BROUGHT PWAT'S
BETWEEN 1.1-1.2" ACROSS THE FA AND THEY ARE EXPECTED TO REACH
NEAR 1.3" BY LATE THIS AFTERNOON. THIS FLOW AND WARM 14-16C
850MB TEMPERATURES BRING AFTERNOON HIGHS BACK INTO THE MID TO
UPPER 80S ONCE AGAIN. NOW FOR OUR SHOWER AND THUNDERSTORM
CHANCES. NOT MUCH HAS CHANGED IN TERMS OF THE THUNDERSTORM
OUTLOOK WHERE LITTLE SYNOPTIC FORCING IS EXPECTED BESIDES SUBTLE
HEIGHT FALLS AS THE TROUGH CONTINUES EASTWARD. THE MAIN DRIVER
LOOKS TO BE STRONG DAYTIME HEATING WHERE BY 2-4PM, THE
CONVECTIVE TEMPERATURE IS REACHED AND WITH PLENTY OF LOW LEVEL
MOISTURE, ISOLATED TO SCATTERED CONVECTION ENSUES. THE RECENT
HRRR RUNS CONTINUE TO HONE IN MAINLY ON THE CENTRAL MIDLANDS AND
INTO THE NORTHERN MIDLANDS AND CSRA, BUT THE 11Z RUN DID SHOW
AN ATTEMPT AT CI ALONG THE SEA BREEZE EARLY THIS EVENING.
OVERALL, NEAR 1000-1500 J/KG OF SBCAPE IS EXPECTED TO DEVELOP
WITH MINIMAL DEEP LAYER SHEAR FOR BETTER STORM ORGANIZATION AND
THIS PRIMARILY PULSE ENVIRONMENT IS EXPECTED TO BE LARGELY SUB-
SEVERE. ONE THING WORTH NOTING IS STEEP LOW LEVEL LAPSE RATES
AND A SOLID INVERTED V MIXED LAYER YIELD MODEST TO HIGH DCAPE
VALUES AND THUS ANY MORE ROBUST STORM COULD BRING STRONG WIND
GUSTS.
MAJORITY OF THIS ACTIVITY WRAPS UP HEADING INTO THE EVENING AND
THE MAIN THING TONIGHT TO KEEP AN EYE ON IS THE PROGRESSION OF
CONVECTION OUT WEST IN ARKANSAS AND TENNESSEE AT THE MOMENT.
MODEL GUIDANCE CONTINUES TO SHOW THIS LARGELY DISSIPATING TOWARD
THE UPSTATE OF GA/SC LATE THIS EVENING AS IT OUTPACES THE
BETTER SYNOPTIC FORCING FROM THE TROUGH BUT A MODEST COLD POOL
MAY BE ABLE TO SNEAK INTO THE FAR NORTHERN MIDLANDS LATE,
BRINGING SOME ISOLATED SHOWERS AND POSSIBLY A WEAK THUNDERSTORM.
BESIDES THIS, OVERNIGHT LOWS REMAIN IN THE LOW TO MID 60S.
SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/
KEY MESSAGE(S):
- THUNDERSTORMS EXPECTED TO MOVE INTO THE AREA LATE SATURDAY
- A FEW STORMS COULD PRODUCE DAMAGING WINDS OR SMALL HAIL
A DEEP, UPPER TROUGH WILL DIG INTO THE EASTERN US AND THEN CUT
OFF OVERNIGHT. AT THE SURFACE, A COLD FRONT WILL PUSH THROUGH
THE SOUTHEAST DURING THE SHORT TERM. CONVERGENCE ALONG THE FRONT
SHOULD LEAD TO CONVECTION DEVELOPING WEST OF THE FORECAST AREA
THEN MOVING EAST THROUGH SATURDAY AFTERNOON AND OVERNIGHT. PWAT
VALUES OF 150 PERCENT OF NORMAL AND A STRONG SHORTWAVE ROUNDING
THE BASE OF THE TROUGH WILL SUPPORT A SEMI-COHERENT LINE OF
CONVECTION AHEAD OF THE FRONT, WITH SOME SCATTERED SHOWERS OUT
AHEAD OF THE MAIN LINE. POPS REMAIN IN THE CHANCE CATEGORY (30
TO 50 PERCENT) DURING THE AFTERNOON THEN RISE TO 60 TO 80
PERCENT IN THE LATE AFTERNOON AND OVERNIGHT AS THE MAIN LINE OF
CONVECTION WORKS ACROSS THE FORECAST AREA. THE HEAVIEST RAIN
RATES SHOULD MOVE ACROSS THE AREA PRETTY QUICKLY LIMITING THE
RISK OF FLOODING. THE MEDIAN RAINFALL ON SAT FROM THE NBM
MEMBERS IS ABOUT 0.75 INCHES WITH ONLY ABOUT ONE THIRD OF
MEMBERS WITH RAINFALL ABOVE AN INCH. MEAN SREF MLCAPE VALUES ARE
AROUND 1000 J/KG SATURDAY AFTERNOON SLIGHTLY LOWER THAN THE
PREVIOUS DAY. EVEN THOUGH INSTABILITY IS WEAK TO MODERATE, STEEP
LOW LEVEL LAPSE RATES COULD SUPPORT SOME DAMAGING WINDS ALONG
THE CONVECTIVE LINE ALTHOUGH THE OVERALL THREAT OF SEVERE
WEATHER IS LOW.
GRADIENT WINDS THROUGH THE DAY WILL BE BREEZY AS THE PRESSURE
GRADIENT TIGHTENS AHEAD OF THE FRONT, BUT DO NOT EXPECT TO REACH
LAKE WIND CRITERIA. TEMPERATURES STILL MILD EVEN WITH THE
POTENTIAL CLOUDS AND RAIN, WITH HIGHS IN THE MIDDLE 80S FOR MOST
AREA. LOWS SATURDAY NIGHT IN THE LOW TO MIDDLE 60S.
LONG TERM /SUNDAY THROUGH THURSDAY/
KEY MESSAGE(S):
- ISOLATED TO SCATTERED RAIN CHANCES SUNDAY
MODELS CONTINUE TO SLOW THE PROGRESSION OF THE FRONT AS THE
UPPER LOW CUTS OFF AND REMAINS NEARLY STATIONARY OVER THE
EASTERN US. THE COLD FRONT WILL SLOWLY WORK ACROSS THE FORECAST
AREA SUNDAY HANGING UP NEAR THE COAST. EXPECT LINGERING SHOWERS
THROUGH THE MORNING AND EARLY AFTERNOON. THERE WILL BE A MINIMAL
SEVERE THREAT WITH INSTABILITY LIMITED TO ALONG THE COASTLINE.
DETERMINISTIC MODELS TEND TO FINALLY PUSH THE FRONT THROUGH THE
AREA ON MONDAY WITH DRIER, COOLER AIR MOVING IN. HOWEVER THERE
REMAINS SOME UNCERTAINTY IN GLOBAL ENSEMBLES WITH SOME MEMBERS
ADVECTING MOISTURE BACK INTO THE EASTERN FA. WITH AN UPPER LOW
NORTHWEST OF THE FA AND SW FLOW REDEVELOPING BY MIDWEEK, THERE
WILL BE AT LEAST A SLIGHT CHANCE OF RAIN THROUGH THE LONG TERM
WITH NEAR NORMAL TEMPERATURES.
AVIATION /14Z FRIDAY THROUGH TUESDAY/
VFR CONDITIONS GENERALLY EXPECTED OUTSIDE OF SHOWERS-STORMS THIS
AFTERNOON-EVENING.
THIS MORNING LIGHT SOUTHERLY TO SOUTH-SOUTHWESTERLY WINDS ARE
SEEN AT ALL SITES WITH SOME SCATTERED MID TO HIGH LEVEL CLOUDS
MOVING THROUGH. THIS MID TO UPPER DECK SHOULD BECOME MORE BROKEN
AS THE DAY PROGRESSES AND EXPECTED SCATTERED CUMULUS SHOULD
DEVELOP INTO THE AFTERNOON. WINDS REMAIN MORE SOUTHERLY MUCH OF
THE DAY AROUND 5-10 KTS WITH SOME GUSTS NEAR 15-17 KTS POSSIBLE.
HAVE PUT A TEMPO GROUP FOR CAE/CUB FOR A COUPLE SHOWERS AND
THUNDERSTORMS THIS AFTERNOON WHERE CONFIDENCE IS GREATEST BUT MAINTAINED
THE PROB30 GROUP FOR THE OTHER SITES AS A COUPLE RECENT MODEL
RUNS DO SUGGEST POSSIBLE DEVELOPMENT ALONG THE SEA BREEZE THIS
AFTERNOON NEAR OGB. WILL ADDRESS THE OTHER TERMINALS WITH THE
HIGHEST CONFIDENCE WITH TEMPO GROUPS IN THE NEXT UPDATE AS MORE
HIGH-RES MODEL GUIDANCE COMES IN. SOUTHERLY WINDS THEN LIGHTEN
OVERNIGHT AND INTO SATURDAY MORNING.
EXTENDED AVIATION OUTLOOK...MORE WIDESPREAD SHOWERS-STORMS
LIKELY ON SATURDAY WITH ASSOCIATED RESTRICTIONS EXPECTED.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
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