023
FXUS62 KCAE 111813
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
213 PM EDT WED MAR 11 2026
WHAT HAS CHANGED
THE RISK FOR SEVERE WEATHER TOMORROW DURING THE MORNING AND
EARLY AFTERNOON HAS INCREASED A BIT. AVIATION DISCUSSION UPDATED
FOR 18Z TAFS.
KEY MESSAGES
- 1. A FRONT CROSSING THE REGION TOMORROW BRINGS THE CHANCE FOR
A COUPLE STRONG TO SEVERE THUNDERSTORMS. GUSTY WINDS OUTSIDE
OF THUNDERSTORMS ARE LIKELY AS WELL.
- 2. NEAR RECORD TEMPERATURES THIS AFTERNOON BEFORE
TEMPERATURES VARY QUITE A BIT THROUGH THE END OF THE PERIOD.
DISCUSSION
KEY MESSAGE #1: A FRONT CROSSING THE REGION TOMORROW BRINGS THE
CHANCE FOR A COUPLE STRONG TO SEVERE THUNDERSTORMS. GUSTY WINDS
OUTSIDE OF THUNDERSTORMS ARE LIKELY AS WELL.
AS THE UPPER LOW CONTINUES TO PHASE WITH THE NORTHERN STREAM
TROUGH OVER THE COMING 24 HOURS, ROBUST LOW LEVEL MOISTURE
ADVECTION SHOULD TAKE PLACE WITH PWAT'S RAISING ABOVE 1.25"
TONIGHT AND NEAR 1.50" THURSDAY MORNING. THIS COMES AS A 35-45
KT LLJ SETS UP AHEAD OF THE SURFACE COLD FRONT THAT SHOULD BE
NEARING THE REGION BY EARLY THURSDAY MORNING. SLIGHT TIMING
DIFFERENCES STILL EXIST IN WHEN A LINE OF THUNDERSTORMS MOVES
THROUGH THE CWA, BUT THE GENERAL WINDOW SEEMS TO BE DURING THE
12-16Z TIMEFRAME. THE SLIGHT TIMING DIFFERENCES STILL MAKES THE
SEVERE THREAT WITH THIS LINE A BIT CONDITIONAL, BUT BETTER
AGREEMENT ACROSS GUIDANCE THAN 24 HOURS AGO DOES BRING MORE
CONFIDENCE IN POTENTIAL STRONG TO SEVERE STORMS WITHIN THIS
LINE. A GLANCE AT THE LATEST CAM'S SHOWS THIS LINE ENTERING THE
WESTERN FA BY 12-14Z, CONTINUING ACROSS THE FA UNTIL CLEARING
THE SOUTHEASTERN MIDLANDS BY 16-18Z WHERE THE GREATEST THREAT
LOOKS TO BE DAMAGING WIND GUSTS, THOUGH THERE IS A NON-ZERO
TORNADO THREAT.
NEARLY 50 KTS OF FLOW IS SEEN IN FORECAST SOUNDINGS ATOP THE
BOUNDARY LAYER AND THUS HIGH-RES RUNS INCLUDING THE LATEST HRRR
AND HREF GUIDANCE INDICATE THIS COULD BE MIXED DOWN TO THE
SURFACE AS THE SURFACE PRESSURE GRADIENT ALSO TIGHTENS AHEAD OF
THE FRONT. THIS IS FURTHER SUPPORTED IN THE 12Z NCAR HRRR NEURAL
NETWORK GUIDANCE WITH PROBABILITIES FOR GUSTS GREATER THAN 50
KTS EXCEEDING 30% IN SOME POINTS. INSTABILITY AHEAD OF THIS LINE
IS EXPECTED TO BE RATHER MEAGER WITH MLCAPE GENERALLY UNDER
500-700 J/KG, BUT WITH NEARLY 60 KTS OF DEEP LAYER SHEAR RUNNING
PARALLEL TO THE FRONT, A LOOSELY ORGANIZED LINE OF STORMS SEEMS
LIKELY. WITH THE STRONG LLJ IN PLACE, THERE IS ALSO 40-45 KTS
OF 0-3KM SHEAR OUT OF THE SOUTH-SOUTHWEST EVIDENT IN FORECAST
SOUNDINGS LEADING TO 3KM SRH VALUES AROUND 150 M^2/S^2, THUS
WHILE THE THREAT IS SECONDARY TO WIND GUSTS, AN ISOLATED TORNADO
CANNOT FULLY BE RULED OUT IN THIS LINE. DUE TO THESE FACTORS,
THE CWA IS OUTLINED IN A MARGINAL RISK (LEVEL 1 OUT OF 5) FOR
SEVERE WEATHER TOMORROW.
THE FRONT MOVES THROUGH THE FA AND TURNS WINDS OUT OF THE
NORTHWEST THEN NORTH DURING THE LATE MORNING TO EARLY AFTERNOON,
DRIVING STRONG WINDS AS THE SURFACE GRADIENT REMAINS TIGHT AND
THE STRONG LLJ REMAINS IN PLACE. THIS SHOULD DRIVE WIND GUSTS UP
TO 30-35 MPH ACROSS THE REGION OUTSIDE OF THE LINE OF
THUNDERSTORMS WHERE A COUPLE GUSTS PUSHING 40 MPH CANNOT BE
RULED OUT AS HREF PROBABILITIES FOR GUSTS GREATER THAN 35 MPH
REACH 30-40%. A LAKE WIND ADVISORY WILL BE IN EFFECT FROM 10 AM
TOMORROW THROUGH 8 PM DUE TO THIS. WINDS THEN DECAY INTO THE
EVENING HOURS AND THROUGH THE OVERNIGHT.
KEY MESSAGE #2: NEAR RECORD TEMPERATURES THIS AFTERNOON BEFORE
TEMPERATURES VARY QUITE A BIT THROUGH THE END OF THE PERIOD.
TEMPERATURES ARE WITHIN A COUPLE DEGREES OF RECORDS AT CAE/AGS
THIS AFTERNOON AND STILL HAVE TIME TO NEAR THIS OVER THE COMING
HOURS AS THE APEX OF THE RIDGE MOVES OVERHEAD. AFTER THIS,
VARYING TEMPERATURES ARE EXPECTED THROUGH THE END OF THE
FORECAST PERIOD. TEMPERATURES THURSDAY REMAIN A BIT UNCERTAIN
DEPENDING ON THE TIMING OF THE FRONT, BUT SHOULD GENERALLY SEE
HIGHS IN THE UPPER 60S TO LOWER 70S BY 8-10 AM BEFORE
TEMPERATURES FALL THE REMAINDER OF THE DAY WITH OVERNIGHT LOWS
INTO FRIDAY MORNING NEARING THE MID TO UPPER 30S FOR THE FIRST
TIME IN A WHILE. TEMPERATURES LIKELY REMAIN NEAR AVERAGE FRIDAY
BEFORE RAISING ABOVE AVERAGE THIS WEEKEND AHEAD OF THE NEXT
SYSTEM. COOLER CONDITIONS ARE SHOWN IN ENSEMBLE GUIDANCE FOR THE
EARLY WEEK WITH NEAR NORMAL TEMPERATURES MONDAY THAT THEN FALL
BELOW NORMAL TUESDAY AND INTO THE MID WEEK. THERE COULD BE
MULTIPLE NIGHTS EARLY NEXT WEEK THAT SEE LOWS INTO THE 30S, BUT
CONFIDENCE IN HOW CHILLY IT GETS IS NOT HIGH AT THE MOMENT.
AVIATION /18Z WEDNESDAY THROUGH MONDAY/
VFR CONDITIONS EXPECTED THIS AFTERNOON AND EVENING, SHOWERS-
STORMS BRING RESTRICTIONS THURSDAY MORNING.
AHEAD OF AN APPROACHING FRONT, GUSTY SOUTHWEST WINDS WILL PUSH
OVER 25 KNOTS THIS AFTERNOON AND EVENING. OTHER THAN SOME MID-
LEVEL STRATO-CU, NOT MUCH IN THE WAY OF NOTABLE CLOUD COVER IS
EXPECTED. WINDS WEAKEN A BIT THIS EVENING, REMAINING 6-10 KNOTS
OUT OF THE SOUTHWEST OVERNIGHT. THE FRONT ITSELF WILL PUSH
THROUGH EARLY THURSDAY MORNING AND IMPACT ALL TAF SITES. FOR
NOW, INCLUDED A TEMPO GROUP TO COVER THE TSRA IMPACTS FROM
ROUGHLY 12-18Z DEPENDING ON THE SITES; GUSTY WINDS OVER 35 KNOTS
ARE LIKELY BUT TIMING IS STILL SOMEWHAT UNCERTAIN WITHIN THAT
TEMPO WINDOW. SOME LINGERING SHOWERS ARE EXPECTED BEHIND THE
STRONGEST STORMS, WITH WINDS TURNING OUT OF THE WEST FOR THE
AFTERNOON.
EXTENDED AVIATION OUTLOOK...NO NOTABLE RESTRICTIONS EXPECTED
FOLLOWING THE COLD FRONT ON THURSDAY WITH THE NEXT CHANCE FOR
SIGNIFICANT IMPACTS HOLDING OFF UNTIL EARLY NEXT WEEK.
CAE WATCHES/WARNINGS/ADVISORIES
SC...LAKE WIND ADVISORY FROM 10 AM TO 8 PM EDT THURSDAY FOR SCZ016-
018-020>022-025>031-035-037-038-041-115-116-135>137.
GA...LAKE WIND ADVISORY FROM 10 AM TO 8 PM EDT THURSDAY FOR GAZ040-
063>065-077.
DISCUSSION...DH
AVIATION...42
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