330
FXUS62 KCAE 021201
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
801 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 SLOW MOVING TROUGH TO OUR WEST WILL STEADILY START TO INFLUENCE
OUR SENSIBLE WEATHER TODAY DESPITE LITTLE CHANGE IN THE LOW LEVEL
SYNOPTICS. SURFACE HIGH PRESSURE REMAINS OFFSHORE, CONTINUING SOUTH-
SOUTHWESTERLY MOISTURE TRANSPORT INTO THE AREA AND AS SUCH PWAT'S
WILL CLIMB TO AROUND 1.25" THIS AFTERNOON. AS THE AFOREMENTIONED
TROUGH SHIFTS EAST, SOME VERY SUBTLE HEIGHT FALLS ALOFT WILL HELP
SLOWLY DESTABILIZE THE AREA, IN CONJUNCTION WITH STRONG SURFACE
HEATING AND DEW POINTS IN THE 60'S. SO, CONVECTIVE TEMP DRIVEN
SHOWERS-STORMS ARE POSSIBLE THIS AFTERNOON ACROSS THE AREA WITH GOOD
SUPPORT IN THE RRFS, HRRR, AND HREF. BUT GIVEN THE LACK OF A STRONG
FORCING MECHANISM, ONLY EXPECTING A HANDFUL OF SCATTERED SHOWERS
ACROSS THE REGION. ALONG THE SAME LINES, THE LACK OF STRONG SYNOPTIC
SUPPORT WILL YIELD VERY LIMITED SHEAR AND LITTLE-NO ORGANIZATION,
BUT DEEP LOW LEVEL MIXING AND THETA-E DEFICITS SUPPORT SOME
GUSTY WINDS IN ANY STORMS THAT DEVELOP.
A NOTABLE QUESTION MARK IS THE DOWNSTREAM PROGRESSION OF THE
NEXT SHORTWAVE MOVING THROUGH THE BROAD MAIN TROUGH AND THE
ASSOCIATED MCS LATE FRIDAY EVENING AND OVERNIGHT. DIURNAL
TIMING AND A LACK OF MUCH ELEVATED INSTABILITY SHOULD FAVOR
RAPID WEAKENING, BUT MUCH OF THE HI- RES DOES SHOW AN MCS
DECAYING INTO EASTERN GA. WHILE THE SEVERE THREAT WOULD BE
LIMITED, IT IS SOMETHING TO MONITOR AND THESE DECAYING MCS CAN
TRICK HI-RES GUIDANCE AND COLD POOL PROPAGATE MUCH FURTHER EAST
THAN ORIGINALLY FORECAST.
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 /12Z 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.
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