018
FXUS62 KCAE 271754
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
154 PM EDT TUE MAY 27 2025
SYNOPSIS
AN UNSETTLED WEATHER PATTERN RESULTS IN SHOWER AND THUNDERSTORM
CHANCES MUCH OF THE WEEK. WEDGE CONDITIONS WILL FINALLY BREAK
DOWN ON WEDNESDAY, 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 CONTINUES TO YIELD LOW CLOUDS AND COOL
TEMPERATURES
- APPROACHING SHORTWAVE EXPECTED TO YIELD WIDESPREAD SHOWERS
AND THUNDERSTORMS THIS EVENING
LATEST SATELLITE IMAGERY, ALONG WITH SURFACE OBSERVATIONS,
REVEALS A STRONG COLD-AIR DAMMING EVENT IN PLACE ACROSS THE
FORECAST AREA. THE AXIS OF THE SURFACE RIDGE EXTENDS FROM THE
SOUTHEASTERN VIRGINIA COAST THROUGH CENTRAL NC AND SC AND INTO
CENTRAL GA. THE WEDGE FRONT IS ANALYZED JUST SOUTH OF OUR
FORECAST AREA, DENOTED LARGELY BY A SHIFT IN SURFACE WINDS FROM
NORTHEASTERLY TO EASTERLY. ISENTROPIC LIFT THAT FORCED EARLIER
RAINS HAS SHIFTED TO THE NORTHEAST, WITH A BREAK IN THE ACTION
CURRENTLY ACROSS THE FORECAST AREA. THIS IS EXPECTED TO CHANGE
THIS AFTERNOON AND EVENING AS A STRONG SHORTWAVE, CURRENTLY
ACROSS THE LOWER MS VALLEY, SHIFTS NORTHEASTWARD. STRONG FORCING
FOR ASCENT, AS WELL AS PWS IN THE 1.8"-2.0" RANGE, WILL FAVOR
NUMEROUS SHOWERS AND THUNDERSTORMS DEVELOPING THIS AFTERNOON AND
EVENING ACROSS THE AREA.
THE QUESTION BECOMES WHAT, IF ANY, SEVERE THREAT MATERIALIZES.
THE ONLY REAL AREA THAT COULD SEE SEVERE WEATHER (REALISTICALLY)
IS OUR SOUTHERN COUNTIES THIS AFTERNOON AND EVENING AS THEY ARE
CLOSEST TO THE WEDGE FRONT. IT HAS SHOWN SOME SIGNS OF SLOWLY
MIXING AND LIFTING NORTHWARD OVER THE LAST COUPLE OF HOURS BUT
IT HAS BEEN VERY SLOW TO DO SO, AND LEAVES A LOT OF DOUBT AS TO
WHETHER ENOUGH SURFACE INSTABILITY WILL BE ABLE TO DEVELOP
ANYWHERE IN OUR FORECAST AREA TO YIELD A SEVERE THREAT. STILL,
THE HRRR AND MEMBERS OF THE REFS SHOW WIDESPREAD CONVECTION
DEVELOPING AND LOOSELY ORGANIZING, WHICH COULD YIELD A THREAT
FOR DAMAGING WINDS IF INSTABILITY DEVELOPS. TEMPS ARE TRICKY AS
THE CENTRAL AND NORTHERN MIDLANDS ARE LIKELY TO REMAIN SOLIDLY
WEDGED IN THIS AFTERNOON AND EVENING, WITH THAT BEING REINFORCED
BY ANY CONVECTION THAT DOES DEVELOP. I CAN SEE A SCENARIO WHERE
THE FAR SOUTHERN PARTS OF THE AREA GET INTO THE MID 70S WITH
SOME SUNSHINE BUT OVERALL I STILL REMAIN SKEPTICAL OF THAT.
FLASH FLOODING DOES APPEAR TO BE A THREAT THIS AFTERNOON AND
EVENING WITH THIS CONVECTION, ESPECIALLY FOR THOSE NEAR THE
FRONT ITSELF. THIS MAY BECOME A FORCING MECHANISM FOR TRAINING
CONVECTION AS MID-LEVEL FLOW LOOKS TO BE PARALLEL OR CLOSE TO
PARALLEL TO THE SURFACE FRONT. THE EXPERIMENTAL REFS AND
OPERATIONAL HREF ARE BOTH SHOWING AN LPMM 6H QPF AXIS OF UP TO
2-4" OF RAINFALL SOMEWHERE RIGHT ALONG THE BOUNDARY. WHILE THE
EXACT LOCATION OF THIS IS TOUGH TO PIN DOWN, THE LPMM PRODUCT
DOES SHOW SOME SKILL IN SHOWING A SIGNAL FOR ENHANCED RAINFALL
POTENTIAL, SO THOSE FROM BURKE TO ORANGEBURG TO CLARENDON COUNTY
NEED TO BE ON THE LOOKOUT FOR POTENTIAL FLASH FLOODING THIS
EVENING, ESPECIALLY SINCE THIS AREA HAS RECEIVED ANYWHERE FROM
5" TO 12" OF RAINFALL THIS MONTH. TONIGHT, PERIODIC SHOWERS AND
EMBEDDED THUNDERSTORMS ARE EXPECTED AS THE SHORTWAVE PUSHES
THROUGH THE REGION, WITH LOWS GENERALLY IN THE LOW TO MID 60S.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
KEY MESSAGE(S):
- THE WEDGE IS EXPECTED TO ERODE WEDNESDAY WITH WARMER
TEMPERATURES EXPECTED.
- ISOLATED RAIN/STORM CHANCES MAY EXIST DURING PEAK HEATING
WEDNESDAY.
- ADDITIONAL RAIN EXPECTED ON THURSDAY AS NEXT SHORTWAVE MOVES
IN.
WEDNESDAY AND WEDNESDAY NIGHT: DAY WILL START OFF WITH THE WEDGE
STILL ACROSS MUCH OF THE FORECAST AREA, WITH THE MOST ENTRENCHED
PART OVER THE WESTERN HALF OF THE FORECAST AREA. SHOULD BE AN
AREA OF RAINFALL EXITING OFF TO THE EAST EARLY IN THE DAY.
BEHIND THIS SYSTEM, THE WEDGE IS EXPECTED TO BEGIN TO SCOUR OUT
DURING THE AFTERNOON HOURS, BRINGING A RETURN OF SOME SUNSHINE
AND WARMER TEMPERATURES. HIGHS WILL BE BACK INTO THE LOW TO MID
80S ONCE AGAIN. THERE WILL BE A LACK OF ANY SIGNIFICANT TRIGGERS
FOR SHOWERS, SO A SOMEWHAT DRIER DAY SHOULD OCCUR FOR MUCH OF
THE MIDLANDS AND CSRA. EVEN SO, AN ISOLATED SHOWER CAN NOT BE
RULED OUT DURING PEAK HEATING, ESPECIALLY CLOSER TO THE COAST.
THESE CHANCES LIKELY DIMINISH INTO THE OVERNIGHT WITH LOWS INTO
THE MID TO UPPER 60S.
THURSDAY AND THURSDAY NIGHT: EXPECTING TO SEE A LITTLE MORE
ACTIVITY REGARDING SHOWERS AND THUNDERSTORMS, ESPECIALLY DURING
THE AFTERNOON HOURS. WHILE THERE WILL STILL BE LIMITING SURFACE
BOUNDARIES, THERE WILL BE A STRONG SHORTWAVE MOVING OVER THE
REGION DURING THE AFTERNOON AND EVENING HOURS. CAPE VALUES
INCREASE BY THAT POINT, AND THERE WILL BE SOME WEAK SHEAR IN
PLACE. IN ADDITION, PWATS WILL REMAIN HIGH THROUGH THE PERIOD.
AS THE SHORTWAVE MOVES IN, EXPECT TO SEE AN INCREASE IN SHOWER
AND THUNDERSTORM COVERAGE. A FEW STRONG TO POSSIBLY SEVERE
STORMS CAN NOT BE RULED OUT, ALONG WITH PERIODS OF HEAVY
RAINFALL DUE TO THE HIGH MOISTURE CONTENT ACROSS THE REGION.
CIPS PROBABILITIES SHOW OVER 15 PERCENT CHANCE OF SOME SORT OF
SEVERE WEATHER ON THURSDAY AFTERNOON/NIGHT OVER MUCH OF THE CWA,
WHILE THE CSU PROBABILITIES SHOW A SLIGHTLY SMALLER AREA
CONFINED MORE TO THE SOUTHERN COUNTIES.
LONG TERM /FRIDAY THROUGH MONDAY/
KEY MESSAGE(S):
- ANOTHER SHOT OF RAIN/STRONGER STORM CHANCES COME FRIDAY AS A
COLD FRONT MOVES THROUGH.
- TEMPERATURES REMAIN NEAR AVERAGE MUCH OF THE PERIOD WITH
POTENTIAL DRIER WEATHER OVER THE WEEKEND.
FRIDAY/FRIDAY NIGHT: A COLD FRONT BE POISED TO PUSH INTO THE
AREA DURING THE DAY AND AFTERNOON HOURS ON FRIDAY. IN ADDITION A
DEEPENING UPPER LOW WILL BE DIGGING SOUTHEASTWARD INTO THE
REGION. SHEAR AND INSTABILITY INCREASES, THE BETTER DYNAMICS
WILL BE PUSHING THROUGH. UPPER LEVEL DIVERGENCE WILL SPREAD OVER
THE CWA DURING THE DAY AS A STRONG UPPER JET MOVES ACROSS. IN
LOWER LEVELS, A GOOD LOW-LEVEL JET OF 30-40 KNOTS MOVES THROUGH.
FRONT IS NOT EXPECTED UNTIL THE AFTERNOON/EVENING HOURS, SO IT
WILL BE MOVING THROUGH DURING A PRIME TIME FOR STRONGER STORMS
TO DEVELOP. SPC DOES HAVE A MAJORITY OF THE CWA IN A 15 PERCENT
AREA FOR SEVERE STORMS, SO FRIDAY WOULD BE A GOOD DAY TO REMAIN
WEATHER AWARE ACROSS THE REGION.
SATURDAY AND BEYOND: BEHIND THE FRONT, DRIER AIR WILL FINALLY
PUSH INTO THE REGION THROUGH THE WEEKEND. LATEST BLENDS HAVE
LATCHED ON TO THE VERY LOW POPS, SO DRY WEATHER SHOULD PREVAIL
INTO EARLY NEXT WEEK. TEMPERATURES REMAINING SLIGHTLY BELOW
NORMAL THROUGH THE WEEKEND, THEN RETURN TO CLOSER TO NORMAL FOR
NEXT WEEK.
AVIATION /18Z TUESDAY THROUGH SUNDAY/
IFR AND PERIODIC LIFR RESTRICTIONS CONTINUE TODAY AND TONIGHT.
WHAT A WEDGE! A CLASSIC WEDGE SETUP IS STILL PRESENT ACROSS THE
CAROLINAS AND IS PROVIDING WIDESPREAD LIFR AND IFR RESTRICTIONS.
GENERALLY, PREDOMINANT IFR IS EXPECTED GOING FORWARD THIS
AFTERNOON, LIKELY APPROACHING MVFR AT OGB AND AGS/DNL WHERE THE
WEDGE FRONT WILL BE CLOSE. BUT IN TERMS OF CEILINGS, WE ARE
SOCKED IN LIKELY THROUGH THE END OF THE PERIOD. WEATHERWISE,
THINGS ARE MUCH MORE INTERESTING. WIDESPREAD SHOWERS AND
THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND EVENING, WITH THE
BEST CHANCE OF THUNDER AT THE AUGUSTA AND ORANGEBURG SITES. HAVE
A FAIRLY AGGRESSIVE TEMPO GROUP THERE FROM 22Z TO 01Z FOR HEAVY
RAIN IN THUNDERSTORMS AND LOW VISIBILITY AS WELL. GUIDANCE IS
CONSISTENT THAT WIDESPREAD THUNDERSTORMS SHOULD BEGIN DEVELOPING
ALONG AND NORTH OF THE WEDGE FRONT AS SHORTWAVE FORCING
ARRIVES, LEADING TO AN EXTENDED PERIOD OF HEAVY RAIN AND
THUNDERSTORMS. COLUMBIA WILL LIKELY SEE THUNDER BUT HEAVY
THUNDERSTORMS ARE A BIT MORE UNCERTAIN HERE AS THE BEST
INSTABILITY WILL RESIDE TO OUR SOUTH. STILL, HAVE A PRETTY
AGGRESSIVE PROB30 IN THERE FOR ANY THUNDERSTORMS THAT MAY SNEAK
UP HERE. RAIN SHOWERS WILL LIKELY CONTINUE PERIODICALLY TONIGHT
AS THE SHORTWAVE PUSHES THROUGH THE REGION.
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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