666
FXUS62 KCAE 280818
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
418 AM EDT WED MAY 28 2025
SYNOPSIS
AN UNSETTLED WEATHER PATTERN RESULTS IN SHOWER AND THUNDERSTORM
CHANCES MUCH OF THE WEEK. WEDGE CONDITIONS WILL FINALLY BREAK
DOWN TODAY, WITH TEMPERATURES RETURNING TO MORE SEASONAL VALUES
FOR THE MID TO LATE WEEK PERIOD. SHOWERS AND STRONGER STORMS
POSSIBLE THURSDAY AND FRIDAY, THEN A RETURN TO DRIER WEATHER
SEEMS POSSIBLE BY THE WEEKEND.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGE(S):
- COLD-AIR DAMMING WILL CONTINUES TO YIELD LOW CLOUDS AND RELATIVELY
COOL TEMPERATURES THIS MORNING BEFORE ERODING LATER TODAY.
- ISOLATED RAIN/STORM CHANCES MAY EXIST DURING PEAK HEATING
LATER THIS AFTERNOON.
SATELLITE IMAGERY REVEALS OVERCAST CONDITIONS CONTINUE OVER THE
FORECAST AREA THIS MORNING IN LIGHT OF A COLD-AIR DAMMING WEDGE
STILL IN PLACE. AN AREA OF SHOWERS HAVE MOVED OFF TO THE NORTHEAST,
AND MOST LOCATIONS ARE NOW RAIN-FREE. THERE REMAINS A WEAK AREA OF
PRECIP OFF TO OUR WEST ACROSS CENTRAL GA, BUT CONFIDENCE IS LOW THAT
IT WILL MAKE IT TO OUR AREA. AS SUCH, POPS ARE ON THE LOW SIDE FOR
MUCH OF THIS MORNING, WITH MOST MODEL GUIDANCE KEEPING THE AREA RAIN-
FREE. TEMPERATURES WILL REMAIN COOL THIS MORNING WITH LOWS IN THE
UPPER 50S AND LOW 60S.
COPIOUS MOISTURE WILL REMAIN OVER THE AREA THIS MORNING, WITH
OVERCAST SKIES AND TEMPERATURES STRUGGLING TO WARM VERY MUCH. THE
WEDGE IS EXPECTED TO BEGIN TO SCOUR OUT DURING THE AFTERNOON HOURS
AS HIGH PRESSURE MOVES OFF TO THE NORTHEAST AND SOME DRIER AIR MIXES
IN, WITH PWATS DECREASING TO AROUND 1". THIS SHOULD EVENTUALLY BRING
A FEW BREAKS IN THE CLOUDS AND THE RETURN OF SOME SUNSHINE WHICH
SHOULD ALLOW TEMPERATURES TO WARM QUITE QUICKLY LATE THIS AFTERNOON
INTO THE LOW TO MID 80S. HOWEVER, IF THE WEDGE TAKES A BIT LONGER TO
MIX OUT THEN THESE TEMPERATURES MAY BE A BIT OVERDONE. A FEW MODELS
DO CONTINUE TO SHOW AN AREA OF SHOWERS AND ISOLATED STORMS MOVING
THROUGH THE UPSTATE AND PERHAPS THE CENTRAL/WESTERN MIDLANDS THIS
AFTERNOON, BUT WITH A LACK OF ANY SIGNIFICANT TRIGGERS OR UPPER
SUPPORT, COVERAGE SHOULD BE LIMITED. RAIN CHANCES DIMINISH INTO THE
OVERNIGHT PERIOD WITH SKIES STILL CLEARING. EXPECT OVERNIGHT LOWS IN
THE MID TO UPPER 60S.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/
KEY MESSAGE(S):
- MORE RAIN/STORM CHANCES EXPECTED ON THURSDAY AS A SHORTWAVE
MOVES IN.
- COLD FRONT MOVES THROUGH FRIDAY BRINGING CHANCE FOR STRONG TO
SEVERE STORMS DURING THE AFTERNOON.
- TEMPERATURES NEAR AVERAGE EXPECTED EACH DAY.
THURSDAY AND THURSDAY NIGHT: AS A DEEP UPPER TROUGH DIGS INTO
THE CENTRAL US THURSDAY, A FAIRLY STRONG SHORTWAVE IS PROGGED TO
MOVE THROUGH THE FA, BRINGING INCREASED CHANCES AND COVERAGE OF
SHOWERS/STORMS DURING THE AFTERNOON AND EVENING. AS
STRENGTHENING SOUTHWESTERLY MOISTURE TRANSPORT MOVES INTO THE
REGION, PWAT'S RAISE BACK NEAR 1.7-1.8" DURING THE AFTERNOON,
SETTING THE STAGE FOR EFFICIENT RAINFALL PRODUCTION IN ANY
SHOWERS/STORMS. A COUPLE STRONG TO MARGINALLY SEVERE STORMS
CANNOT BE RULED OUT DURING THE AFTERNOON AND INTO THE EVENING AS
BULK SHEAR ON THE ORDER OF 20-30 KTS BEGINS TO OVERSPREAD THE
REGION AND MOIST SOUTHWESTERLY FLOW AIDS IN BRINGING SBCAPE
VALUES OVER 1000 J/KG. WITH THE DEEP MOISTURE IN PLACE AND
LOCALLY HIGH RAIN AMOUNTS SEEN OVER THE PAST COUPLE WEEKS, THE
GREATEST THREAT WOULD APPEAR TO BE HEAVY RAIN AND POSSIBLE
LOCALIZED FLOODING CONCERNS, THOUGH DAMAGING WINDS WOULD ALSO BE
POSSIBLE IN THE STRONGER CELLS. THE MAIN UNCERTAINTY AT THIS
POINT IS THE TIMING OF THE SHORTWAVE. THERE IS A SPLIT IN MODEL
GUIDANCE WHERE THE RAP/GFS HAVE THE SHORTWAVE MOVING IN DURING
THE MID AFTERNOON HOURS BUT A COUPLE HIGH RES MODELS LIKE THE
RECENT HRRR AND MOST RECENT HREF SOLUTION SLOW THE SHORTWAVE
DOWN AND HAVE IT PASSING TOWARD THE EARLY EVENING. THIS SOLUTION
WOULD BRING THE GREATER POP'S/COVERAGE CLOSER TO THE EVENING
AND MAY LIMIT ANY STRONG STORM RISK DUE TO THE LOSS OF DIURNAL
HEATING. OVERALL, THE HIGHEST CONFIDENCE IN THIS ACTIVITY IS
TOWARD THE SOUTHERN FA AND TEMPERATURES DURING THE AFTERNOON
REACH THE MID TO UPPER 80S.
FRIDAY AND FRIDAY NIGHT: THE MAIN UPPER TROUGH BEGINS TO SWING
INTO THE REGION FRIDAY AS IT CONTINUES TO DEEPEN AND STRONG
UPPER DYNAMICS OVERSPREAD THE FA. BY THE AFTERNOON, 90-100 KTS
OF 300 MB SOUTHWESTERLY FLOW OVERSPREADS THE AREA WITH DECENT
UPPER DIVERGENCE NOTED AND STRONG 500 MB HEIGHT FALLS. AT THE
SURFACE, A COLD FRONT IS PROGGED TO MOVE THROUGH THE FA BY THE
AFTERNOON INTO THE EVENING AND NAEFS IVT REACHES TOWARD THE 97.5
PERCENTILE. GLOBAL AND MEDIUM RANGE GUIDANCE IS ALSO IN FAIRLY
GOOD AGREEMENT THAT A 30-40 KT SOUTHWESTERLY LLJ WILL DEVELOP BY
THE MID AFTERNOON. WITH NEAR AVERAGE TEMPERATURES EXPECTED AND
STRONG MOISTURE TRANSPORT, LREF PROBABILITIES FOR MUCAPE OVER
1000 J/KG ARE BETWEEN 60-70% AND THE OVERALL WIND FIELD IS
MOSTLY UNIDIRECTIONAL, BRINGING FAIRLY STRAIGHT HODOGRAPHS. WITH
THIS STRONG FORCING, A LINE OF CONVECTION AHEAD OF THE FRONT IS
EXPECTED TO PASS THROUGH THE CWA DURING THE AFTERNOON AND INTO
THE EVENING WHERE STRONG TO SEVERE STORMS WILL BE POSSIBLE. THE
SPC HAS INCLUDED THE CWA IN A SLIGHT RISK (LEVEL 2 OUT OF 5) FOR
SEVERE STORMS OVER THE FA AND THIS IS ALSO SUPPORTED BY
MULTIPLE AI/MACHINE LEARNING PRODUCTS SUCH AS CIPS, CSU, AND
NCAR'S ECMWF AI SUITE.
THIS WILL BE A DAY WORTH CONTINUING TO KEEP AN EYE ON AS MORE
DETAILS GET IRONED OUT IN TERMS OF SPECIFIC THREATS. BEHIND THE
FRONT FRIDAY NIGHT, DRIER AIR IS USHERED IN AND DRY CONDITIONS
ARE EXPECTED TO TAKE OVER.
LONG TERM /SATURDAY THROUGH TUESDAY/
KEY MESSAGE(S):
- DRIER CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE MUCH OF
THE EXTENDED PERIOD WITH TEMPERATURES NEAR AVERAGE.
BEHIND FRIDAY'S FRONT, PWATS DROP TO NEAR AVERAGE AS UPPER
TROUGHING IS SLOWLY REPLACED WITH STRONG RIDGING INTO THE START
OF THE NEXT WEEK. ENSEMBLE GUIDANCE IS IN GOOD AGREEMENT THAT
DRIER CONDITIONS SHOULD BEGIN TO TAKE OVER FOR MUCH OF THE
EXTENDED PERIOD. ONE LAST SHORTWAVE MAY ROUND THE RIDGE AXIS TO
THE WEST SOMETIME MONDAY, BUT WITH THE DRIER AIR MASS IN PLACE,
THE CURRENT EXPECTATION IS TO REMAIN MOSTLY ON THE DRY SIDE.
WITH RIDGING SLOWLY WORKING IN, NEAR AVERAGE TEMPERATURES ARE
EXPECTED WITH THE START OF THE WEEK POSSIBLY BEING SLIGHTLY
ABOVE AVERAGE.
AVIATION /08Z WEDNESDAY THROUGH SUNDAY/
HIGH CONFIDENCE IN IFR/LIFR RESTRICTIONS THROUGH LATE MORNING, THEN
GRADUALLY IMPROVING CONDITIONS.
COLD-AIR DAMMING CONDITIONS CONTINUE TO DOMINATE OVER THE REGION
WITH WIDESPREAD IFR/LIFR CIGS IN PLACE AND EXPECTED TO REMAIN
THROUGH THIS MORNING. WINDS SHOULD GENERALLY BE LIGHT AT 5 KNOTS OR
LESS, PERHAPS FAVORING A NORTH TO NORTHEASTERLY DIRECTION. CIGS
SHOULD BEGIN TO SLOWLY IMPROVE TO MVFR AND EVENTUALLY VFR THIS
AFTERNOON AS THE WEDGE ERODES FROM THE SOUTHWEST, WITH INCREASING
WESTERLY WINDS 6 TO 10 KNOTS. THERE IS LOW CONFIDENCE IN A FEW
-SHRA/-TSRA THIS AFTERNOON AT THE TERMINALS, PARTICULARLY
CAE/CUB/AGS/DNL BUT WILL NOT MENTION IN THE TAF AT THIS TIME. ALL
SITES SHOULD BE VFR AFTER 29/00Z THIS EVENING WITH LIGHT AND
VARIABLE WINDS.
EXTENDED AVIATION OUTLOOK...CHANCES OF DIURNAL SHOWERS AND
THUNDERSTORMS THROUGH THE REMAINDER OF THE WEEK WITH THE POTENTIAL
FOR PERIODIC RESTRICTIONS.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
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