375
FXUS62 KCAE 300840
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
440 AM EDT FRI MAY 30 2025
SYNOPSIS
TEMPERATURES RETURNING TO MORE SEASONAL VALUES INTO THE WEEKEND.
A LINE OF STRONG TO SEVERE THUNDERSTORMS IS EXPECTED TO MOVE
THROUGH THE AREA THIS AFTERNOON AHEAD OF A COLD FRONT. WINDS
MAY BE GUSTY TODAY AHEAD OF THE FRONT AND AGAIN ON SATURDAY
BEHIND IT. CALMER WEATHER IS THEN EXPECTED THIS WEEKEND INTO
EARLY NEXT WEEK WITH LOW RAIN CHANCES.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGE(S):
- WIDESPREAD STRATUS EXPECTED THROUGH DAYBREAK.
- A LINE OF STRONG TO SEVERE THUNDERSTORMS EXPECTED THIS AFTERNOON
AS A FRONT MOVES THROUGH THE REGION.
WITH ABUNDANT LOW LEVEL MOISTURE IN PLACE AND SIGNIFICANT RAINFALL
FROM THURSDAY, WIDESPREAD STRATUS HAS DEVELOPED AND IS MOVING
THROUGH THE AREA. THE CLOUD COVER COUPLED WITH A 20-30 KNOT LOW
LEVEL JET IS KEEPING SURFACE WINDS ELEVATED ENOUGH TO LIMIT
RADIATIONAL COOLING, AND MOST LOCATIONS ARE SITTING WITH
TEMPERATURES IN THE UPPER 60S WITH DEWPOINTS IN THE MID 60S. SOME
DRYING ALOFT HAS OCCURRED, AND SATELLITE PWAT ESTIMATES ARE
GENERALLY AROUND 1.4"-1.5". THAT SAID, THE AREA IS NOW PRECIP-FREE
AND SHOULD REMAIN THAT WAY THROUGH MIDDAY EVEN WITH THE STRATUS
REMAINING IN PLACE UNTIL THE INVERSION BREAKS AND ALLOWS FOR DEEPER
MIXING IN THE BOUNDARY LAYER.
TODAY'S WEATHER WILL BE DICTATED BY A PRE-FRONTAL SURFACE TROUGH
ASSOCIATED WITH A STOUT UPPER TROUGH THAT IS PROGGED TO SWING FROM
THE OH VALLEY THROUGH THE MID-ATLANTIC TODAY. THIS BOUNDARY WILL BE
THE FOCUS FOR A LINE OF CONVECTION THAT HAS BEEN WELL MODELED FOR
THE PAST 24 HOURS BY MULTIPLE CAMS. A LINE OF CONVECTION IS EXPECTED
TO DEVELOP OFF TO OUR NORTHWEST THEN MOVE SOUTHEAST THROUGH THE
UPSTATE AND INTO THE MIDLANDS AND CSRA THIS AFTERNOON. FOR TIMING,
GUIDANCE HAS HONED IN ON AN APPROXIMATELY 2 PM TO 7 PM WINDOW FOR
THE LINE THE CLEAR THE CWA; THE WESTERN MIDLANDS AROUND 2-4PM,
CENTRAL MIDLANDS-CSRA 3-6 PM, AND EASTERN MIDLANDS 4-7PM. THIS IS
SLIGHTLY SLOWER THAN PREVIOUS GUIDANCE, BUT ALL MODELS STILL SEEM TO
BE IN GOOD ALIGNMENT AT THIS TIME.
A LINEAR STORM MODE SEEMS MOST LIKELY AS THE TROUGH PUSHES THROUGH,
THOUGH THERE REMAINS SOME QUESTION IN HOW CONNECTED THE LINE WILL BE
WHEN IT REACHES OUR AREA. SOME MODELS KEEP THE LINE SOLIDLY
CONNECTED AS IT MOVES THROUGH, WHILE OTHERS ARE SHOWING SOME BREAKS
IN THE LINE WITH STRONGER BOWING SEGMENTS. THAT SAID, THE
ENVIRONMENT SHOULD FAVOR ALL HAZARDS, THOUGH DAMAGING WIND GUSTS
SEEM TO BE THE PRIMARY THREAT. WITH THE SPEED OF THE LINE, THE FLASH
FLOOD THREAT LOOKS TO BE LOWER THAN THURSDAY, AND WE ARE NOT
EXPECTING ANY TRAINING STORMS AT THIS TIME.
LIMITATIONS ON HOW STRONG THE LINE WILL BE WHEN IT PUSHES THROUGH
INCLUDES THIS MORNING'S STRATUS DECK AND THE AMOUNT OF SOLAR
INSOLATION/DESTABILIZATION WE ARE ABLE TO ACHIEVE. WITH TEMPERATURES
EXPECTED TO REACH THE LOW TO MID 80S AND DEWPOINTS IN THE UPPER
60S, FORECAST SOUNDINGS GENERATE ABOUT 1200-1700 J/KG OF
SBCAPE, WITH LI AROUND -5 AND 40 KTS OF 0-6KM MAINLY
UNIDIRECTIONAL SHEAR. SRH VALUES ARE GENERALLY AROUND 100 M2/S2
OR LESS BOTH 0-1KM AND 0- 3KM, SO WHILE A BRIEF SPINUP CAN'T BE
RULED OUT, FEEL THE TORNADO THREAT IS QUITE LIMITED. IF MORE OR
LESS INSTABILITY BECOMES REALITY, THIS WILL AFFECT THE OVERALL
STRENGTH OF THE LINE WHEN IT MOVES THROUGH AND THEREFORE THE
ASSOCIATED THREATS. A SLIGHT RISK FOR SEVERE HAS BEEN
MAINTAINED BY SPC FOR THE ENTIRE FORECAST AREA.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/
KEY MESSAGE(S):
- DRIER CONDITIONS BEGIN TO TAKE SHAPE FOR THE WEEKEND WITH
NEAR AVERAGE TEMPERATURES.
- GUSTY WINDS ARE EXPECTED SATURDAY AFTERNOON.
- LOW END CHANCE FOR AN ISOLATED SHOWER/STORM SUNDAY AS UPPER
TROUGH DEPARTS.
SATURDAY AND SATURDAY NIGHT: MUCH DRIER AIR FILTERS IN BEHIND
FRIDAY'S COLD FRONT WITH PWAT'S THAT QUICKLY DROP TO UNDER 1".
THIS LOOKS TO YIELD A MUCH DRIER DAY WITH PARTLY CLOUDY TO
MOSTLY CLEAR SKIES. AS THE BASE OF THE DEEP UPPER TROUGH PIVOTS
OVERHEAD, AND A SECONDARY COLD FRONT NEARS THE NORTHERN FA
DURING THE AFTERNOON AND EVENING, HIGH-RES MODEL GUIDANCE
DEPICTS A COUPLE SPOTTY SHOWERS/STORMS FORMING JUST NORTH OF THE
PEE DEE REGION. WITH WESTERLY TO NORTHWESTERLY FLOW TAKING OVER
AND SOME DOWNSLOPING, THE EXPECTATION IS REMAIN MOSTLY ON THE
DRY SIDE WITH PWAT'S ONLY SLIGHTLY RAISING TO NEAR 1". STRONG
INSOLATION SHOULD OVERCOME SOME COLD ADVECTION AND ALLOW
TEMPERATURES TO RAISE INTO THE LOW 80S. THE MAIN ITEM OF
INTEREST SATURDAY WILL BE GUSTY WINDS DURING THE AFTERNOON AS
DEEP MIXING UP TO AROUND 750-700 MB, WHERE NEAR 30-35 KTS OF
NORTHWESTERLY FLOW IS LOCATED, SHOULD ALLOW GUSTS BETWEEN 25-30
MPH TO MIX DOWN. IT WILL BE A BIT BORDERLINE BUT A LAKE WIND
ADVISORY MAYBE NEEDED DURING THE AFTERNOON TO ACCOUNT FOR THIS.
THESE WESTERLY WINDS LIKELY CALM INTO THE EVENING AND OVERNIGHT
WHERE MOSTLY CLEAR SKIES YIELD GOOD COOLING CONDITIONS WITH
OVERNIGHT LOWS EXPECTED IN THE UPPER 50S TO LOW 60S.
SUNDAY AND SUNDAY NIGHT: THE UPPER TROUGH FINALLY BEGINS ITS
DEPARTURE THROUGH THE DAY SUNDAY, BUT MEDIUM RANGE AND GLOBAL
MODELS CONTINUE TO HINT THAT ONE LAST SHORTWAVE MAY ROUND THE
LONGWAVE TROUGH, WITH PWAT'S SLIGHTLY RAISING TO 1-1.2" BY THE
LATE AFTERNOON AND INTO THE EVENING WITH LOW LEVEL WINDS
BECOMING A BIT MORE SOUTHWESTERLY. THIS MAYBE ABLE TO BRING SOME
ISOLATED SHOWERS AND POSSIBLY A THUNDERSTORM TO THE FA DURING
THE LATE AFTERNOON THROUGH THE EVENING, BUT POP'S ARE KEPT
BETWEEN 15-25% TO ACCOUNT FOR THIS DUE TO THE GENERAL LACK OF
MOISTURE. WITH LOW LEVEL SOUTHWESTERLY FLOW TAKING OVER AGAIN,
AFTERNOON TEMPERATURES SHOULD BE A COUPLE DEGREES HIGHER THAN
SATURDAY, IN THE LOW TO MID 80S UNDER PARTLY CLOUDY SKIES. THE
UPPER TROUGH BEGINS TO MOVE OFFSHORE INTO MONDAY MORNING AND
OVERNIGHT LOW ONCE AGAIN FALL INTO THE UPPER 50S TO LOW 60S.
LONG TERM /MONDAY THROUGH THURSDAY/
KEY MESSAGE(S):
- DRIER AND CALMER CONDITIONS THROUGH MUCH OF THE EXTEND WITH
TEMPERATURES THAT SLOWLY REACH A LITTLE ABOVE AVERAGE.
EC EFI CONTINUES TO SHOW A MUCH CALMER EXTENDED PERIOD COMPARED
TO THIS PAST WEEK WITH DRIER CONDITIONS AND NOTHING TOO
ANOMALOUS INTO AT LEAST THE MID WEEK. UPPER TROUGHING IS
REPLACED WITH STRONG RIDGING AS SURFACE HIGH PRESSURE SLIDES
INTO THE REGION, KEEPING NAEFS PWAT'S NEAR TO JUST BELOW AVERAGE
MUCH OF THE PERIOD AND ALLOWING TEMPERATURES TO RISE JUST ABOVE
AVERAGE MAINLY TUESDAY-THURSDAY. THERE IS SOME INDICATOR IN THE
EC ENSEMBLE, THE GEFS, AND THEIR DETERMINISTIC COUNTERPARTS
THAT RIDGING MAY FLATTEN OUT SOME TOWARD THURSDAY WITH A
POTENTIAL TROUGH MOVING INTO THE GREAT LAKES REGION, BUT AT THIS
TIME ANY RAIN CHANCES SEEM TO KEEP JUST WEST OF THE AREA.
AVIATION /08Z FRIDAY THROUGH TUESDAY/
AS DRIER AIR ALOFT MIXES INTO THE FORECAST AREA, EXPECT MVFR/IFR
STRATUS TO CONTINUE THROUGH SUNRISE. IN A FEW LOCATIONS, LIFR
CONDITIONS MAY DEVELOP FOR BRIEF PERIODS OF TIME, WHICH MAY BUILD
DOWN ENOUGH TO RESTRICT VSBYS. EXPECT IFR CEILINGS TO CONTINUE INTO
MID-MORNING UNTIL THE INVERSION MIXES OUT AND SW/WSW WIND GUSTS PICK
UP AROUND 30/15Z ALLOWING A RETURN TO VFR CONDITIONS. A LINE OF
-TSRA WILL LIKELY MOVE ACROSS THE FORECAST AREA THIS AFTERNOON.
STORMS MAY PRODUCE GUSTY AND ERRATIC WINDS OVER 40 KTS AND
POSSIBLY A TORNADO. THE MOST LIKELY TIMING OF THE LINE OF
STORMS WILL BE FROM 30/19Z-22Z. WIND GUSTS AHEAD OF THE LINE
SHOULD RANGE BETWEEN 20 TO 30 KTS. DRY CONDITIONS RETURN THIS
EVENING BEHIND THE LINE OF CONVECTION, AND WINDS WILL ALSO
DIMINISH TO AROUND 5-10 KTS OVERNIGHT WITH A SLIGHT SHIFT TO
THE W/NW.
EXTENDED AVIATION OUTLOOK...LOWER RAIN CHANCES IN THE EXTENDED
COMPARED TO THE PREVIOUS WEEK. EARLY MORNING RESTRICTIONS ARE
POSSIBLE THIS WEEKEND AND EARLY NEXT WEEK BUT WIDESPREAD
RESTRICTIONS UNLIKELY.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
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