774
FXUS62 KCAE 311220
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
820 AM EDT MON MAR 31 2025
SYNOPSIS
WIDESPREAD THUNDERSTORMS, WITH SEVERE STORMS POSSIBLE THIS
AFTERNOON AHEAD OF A COLD FRONT WHICH WILL CROSS THE REGION BY
TONIGHT. WELL ABOVE NORMAL TEMPERATURES EXPECTED FOR LATE WEEK
WITH POSSIBLE RECORD HIGHS LATE WEEK AND NEXT WEEKEND.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGE(S):
- AFTERNOON CONVECTION WITH SEVERE STORMS POSSIBLE
- PRIMARY THREAT IS DAMAGING WINDS BUT ISOLATED TORNADOES AND HAIL
ALSO POSSIBLE
REGIONAL RADAR CURRENTLY SHOWS A LINE OF CONVECTION PUSHING
THROUGH CENTRAL WV AND TN WITH MULTIPLE BOWING SEGMENTS AND A
HISTORY OF DAMAGING WIND GUSTS. A FEW SHOWERS ARE ALSO
DEVELOPING ACROSS THE EASTERN MIDLANDS AND COASTAL PLAIN DUE TO
WEAK ISENTROPIC LIFT. ALOFT, AN UPPER LEVEL TROUGH CONTINUES TO
SHIFT EASTWARD ACROSS THE MIDDLE OF THE COUNTRY WHICH WILL PUSH
A COLD FRONT THROUGH THE AREA BY TONIGHT. AHEAD OF THE FRONT
TODAY, CONTINUED SOUTHERLY LOW LEVEL FLOW AROUND THE WESTERN
ATLANTIC SURFACE HIGH WILL PROVIDE CONTINUED WARM AND MOIST
ADVECTION OVER THE FORECAST AREA LEADING TO AIR MASS
DESTABILIZATION THROUGH THE DAY. MORNING STRATUS MAY DELAY OR
IMPACT THE INITIAL DESTABILIZATION BUT GUIDANCE SUGGESTS MLCAPE
VALUES WILL EXCEED 1000 J/KG DURING PEAK HEATING WITH MODEST BUT
SUFFICIENT EFFECTIVE WIND SHEAR AROUND 30-40 KNOTS WHICH SHOULD
SUPPORT THE THREAT OF SEVERE WEATHER.
LATEST HRRR RUNS CONSISTENTLY SHOWING THIS INITIAL CONVECTIVE
LINE DIMINISHING AS IT MOVES EAST OF THE MOUNTAINS BUT LEAVING A
RESIDUAL OUTFLOW BOUNDARY SOMEWHERE ACROSS THE NORTHERN
MIDLANDS. THIS COULD BECOME A FOCUS FOR ENHANCED HELICITY AND A
INCREASED TORNADO THREAT WHEN AFTERNOON CONVECTION MOVES INTO
THE REGION.
HI-RES GUIDANCE IS IN REASONABLE AGREEMENT DEVELOPING
CONVECTION ACROSS THE GULF COAST STATES AFTER 12Z WHICH THEN
TRACKS EASTWARD THROUGH THE DAY ENCOUNTERING AN INCREASINGLY
UNSTABLE HIGH THETA-E ENVIRONMENT RESULTING IN A LINE OF STRONG
CONVECTION MOVING THROUGH OUR AREA MID TO LATE AFTERNOON
(18Z-01Z) WITH POSSIBLE ISOLATED DISCRETE CELLS DEVELOPING AHEAD
OF THE LINE. HI-RES GUIDANCE ALSO SHOWING SOME UPDRAFT HELICITY
TRACKS MOVING ACROSS THE MIDLANDS AND CSRA WITH A MORE RECENT
ENHANCEMENT OF THEM ACROSS THE NORTHERN MIDLANDS (LIKELY
ASSOCIATED WITH THE FORECAST OUTFLOW BOUNDARY) WHICH IS A CHANGE
FROM PREVIOUS FORECAST THINKING THAT THE TORNADO THREAT WOULD
PRIMARILY BE CONFINED TO THE CSRA AND SOUTHEAST MIDLANDS. SO
WHILE THERE DOES NOT APPEAR TO BE A SIGNIFICANT TORNADO THREAT,
WITH A MORE LIKELY STORM MODE BEING COLD POOL DOMINATED LINEAR
MULTICELLULAR SEGMENTS, THE TORNADO THREAT DOES EXIST ACROSS THE
ENTIRE FORECAST AREA. AS MENTIONED, DAMAGING WIND GUSTS ARE THE
PRIMARY THREAT OF SEVERE WEATHER GIVEN THE FAIRLY
UNIDIRECTIONAL WIND PROFILE BUT LARGE HAIL CANNOT BE RULED OUT
EITHER. PWAT VALUES CONTINUE TO BE HIGH (OVER 200% OF NORMAL)
AND WILL SUPPORT HEAVY RAIN POTENTIAL BUT STORM MOTION SHOULD BE
HIGH ENOUGH TO LIMIT FLASH FLOOD THREAT.
TEMPERATURES TODAY SHOULD WARM AGAIN WELL INTO THE 70S WITH
SOME LOWER 80S POSSIBLE IN THE EASTERN MIDLANDS, DEPENDING ON
HOW QUICKLY THE LOWER STRATUS CAN BURN OFF. AFTER THE CONVECTION
PUSHES EAST OF THE FORECAST AREA THIS EVENING LINGERING CLOUD
COVER WILL LIMIT RADIATIONAL COOLING AND EXPECT SOME RETURN OF
STRATUS DUE TO ABUNDANT LOW LEVEL MOISTURE IN PLACE UNTIL THE
COLD FRONT PUSHES THROUGH. COLD ADVECTION SHOULD COMMENCE BEHIND
THE FRONT LATE TONIGHT AND OVERNIGHT LOWS EXPECTED TO FALL INTO
THE 50S RANGING FROM THE LOWER 50S WEST TO UPPER 50S EAST.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/
- A TRANSIENT COOL, DRY AIRMASS WILL ON TUESDAY WILL MAKE WAY
FOR A STEADY WARM UP AND MOISTURE RETURN THAT STARTS
WEDNESDAY.
FOLLOW MONDAY'S COLD FRONT PASSAGE, TUESDAY WILL BE THE COOLEST DAY
FOR THE FORECAST PERIOD AS TEMPS REMAIN IN THE 70'S. WITH BROAD
COLD, DRY ADVECTION AND DOWNSLOPING, PWAT'S WILL DROP DOWN BELOW
0.5" AND SURFACE DEW POINTS WILL FALL INTO THE 40'S. AS BROAD
OFFSHORE HIGH PRESSURE AND RIDGING DEVELOPS INTO WEDNESDAY, WARMING
TEMPS AND MOISTURE WILL RETURN. SOME UPSLOPE AND ISENTROPICALLY
FORCED SHOWERS ARE POSSIBLE AS WE FLIP OVER TO A WARM ADVECTION
REGIME THANKS TO THAT STRONG BERMUDA HIGH. SO A FEW SHOWERS ARE
EXPECTED MAINLY IN THE UPSTATE AND WESTERN MIDLANDS WEDNESDAY.
OTHERWISE, TEMPS WILL PUSH INTO THE MID 80'S IN MOST SPOTS, 10-15
DEGREES ABOVE AVERAGE.
LONG TERM /THURSDAY THROUGH SUNDAY/
- HIGHLY ANOMALOUS WARMTH EXPECTED WITH NEAR RECORD HIGH TEMPS
THURSDAY THROUGH SUNDAY.
THE LONG TERM PERIOD WILL BE DOMINATED BY DEEP MID-UPPER LEVEL
RIDGING AND AN EXTREMELY STRONG OFFSHORE SURFACE HIGH. THESE WILL
YIELD NEAR OR EXCEEDING RECORD HIGH TEMPS ACROSS MUCH OF THE AREA
STARTING THURSDAY AND LASTING THROUGH SUNDAY; THE TIMING OF WHEN THE
NEXT FRONT ACTUALLY CLEARS THE AREA NEXT WEEK IS STILL UNCERTAIN.
REGARDLESS, HIGH TEMPS WELL INTO THE 80'S OR LOW 90'S ARE EXPECTED
DURING THIS WINDOW, WITH A REMARKABLE SIGNAL IN THE EC EFI AND NAEFS
FOR ANOMALOUS MAX AND MIN TEMPS. EC EFI SHOWS CONSISTENT 0.9+ WITH
SOT OF OVER 1.0 FOR BOTH MAX AND MIN TEMPS FRIDAY AND SATURDAY.
NAEFS SHOWS NEAR RECORD 500MB HEIGHTS OFF THE ATLANTIC COAST WITH
99TH PERCENTILE HEIGHTS AND TEMPS THROUGHOUT FRIDAY AND SATURDAY. SO
OVERALL, GUIDANCE IS FLAGGING THIS PERIOD AS ONE OF THE MORE
ANOMALOUS TEMP PATTERNS WE HAVE SEEN IN AWHILE. EXACTLY WHEN THIS
RIDGING WILL CLEAR OUT IS A BIT UNCERTAIN, BUT GEFS AND ECE BOTH
PUSH A STRONG FRONT THROUGH THE REGION SOMETIME SUNDAY OR MONDAY OF
NEXT WEEK, FOLLOWING BY A NOTABLE COOL-DOWN INTO THE EXTENDED RANGE.
AVIATION /12Z MONDAY THROUGH FRIDAY/
IFR CEILINGS CONTINUE THIS MORNING BEFORE SHOWERS AND
THUNDERSTORMS THIS AFTERNOON LEAD TO POSSIBLE RESTRICTIONS.
IFR STRATUS CONTINUES TO BE SEEN AT ALL SITES THIS MORNING WITH
CALM TO LIGHT SOUTHWEST WINDS BEING SEEN. CEILINGS ARE EXPECTED
TO RISE BY 15Z-16Z AS SOUTHWESTERLY WINDS INCREASE TO AROUND
10-15 KNOTS WITH GUSTS TO 20-25 KTS POSSIBLE. AFTER THIS, VFR
CONDITIONS ARE EXPECTED INTO THE EARLY AFTERNOON BUT MODEL
GUIDANCE CONTINUES TO SHOW A LINE OF STORMS MOVING THROUGH THE
AREA AHEAD OF A COLD FRONT DURING THE AFTERNOON HOURS WITH
POSSIBLE SEVERE STORMS. I AM MAINTAINING THE TEMPO FOR TSRA AND
ENHANCED WIND GUSTS FROM 19-22Z AT ALL SITES BUT OGB, WHERE THE
TIMING IS LOOKING CLOSER TO 20-23Z. VISIBILITY AND CEILING
RESTRICTIONS WILL BE POSSIBLE WITH THE PASSING OF THIS LINE AS
WELL. BEHIND THE LINE, SOUTHWEST WINDS LIGHTEN AND WITH ABUNDANT
MOISTURE REMAINING IN PLACE BEFORE THE COLD FRONTS PASSING INTO
TUESDAY MORNING, ANOTHER STRATUS DECK IS EXPECTED TO FORM AFTER
6-8Z UNTIL THE END OF THE CURRENT PERIOD WITH ASSOCIATED
RESTRICTIONS NEARING IFR CONDITIONS AGAIN.
EXTENDED AVIATION OUTLOOK...THE COLD FRONT IS EXPECTED TO MOVE
THROUGH THE AREA TONIGHT WITH LINGERING POSSIBLE RESTRICTIONS
INTO EARLY TUESDAY. EARLY MORNING LOW CLOUDS CONTINUE TO BE
POSSIBLE WEDNESDAY AND THURSDAY MORNING.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
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