643
FXUS62 KCAE 151826
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
226 PM EDT SUN MAR 15 2026
WHAT HAS CHANGED
CONDITIONAL THREAT FOR ISOLATED SEVERE THUNDERSTORMS CONTINUES
THROUGH THIS EVENING AND CONFIDENCE REMAINS HIGH IN A POTENTIAL
SEVERE WEATHER OUTBREAK ON MONDAY. AVIATION DISCUSSION UPDATED
FOR 18Z TAFS.
KEY MESSAGES
- 1. CONDITIONAL THREAT FOR SEVERE THUNDERSTORMS THIS AFTERNOON
AS A SHORTWAVE LIFTS THROUGH THE AREA.
- 2. A SIGNIFICANT SEVERE WEATHER OUTBREAK IS POSSIBLE ON
MONDAY, WITH DESTRUCTIVE WIND GUSTS (75+ MPH) AND STRONG
TORNADOES (EF2+) POSSIBLE AS A LINE OF STORMS PUSHES THROUGH
THE AREA. A MODERATE RISK (4/5) OF SEVERE WEATHER EXISTS FOR
PART OF THE AREA, WITH THE REST OF THE AREA IN AN ENHANCED
RISK (3/5).
- 3: SUBFREEZING TEMPERATURES POSSIBLE MULTIPLE NIGHTS THIS
WEEK. THERE IS POTENTIAL FOR A HARD FREEZE TUESDAY NIGHT INTO
EARLY WEDNESDAY.
DISCUSSION
KEY MESSAGE 1: CONDITIONAL THREAT FOR SEVERE THUNDERSTORMS THIS
AFTERNOON AS A SHORTWAVE LIFTS THROUGH THE AREA.
CONDITIONAL THREAT FOR ISOLATED SEVERE THUNDERSTORMS THIS
AFTERNOON CONTINUES AS A SHORTWAVE LIFTS NORTHWARD THROUGH
GEORGIA, NOTED ON WV/VIS SATELLITE IMAGERY. SURFACE DEWPOINTS
CONTINUE TO RISE ACROSS THE AREA WITH THE BEST SURGE OCCURRING
IN THE CSRA WHERE DEWPOINTS ARE IN THE MID 60S AT ALLENDALE AND
BARNWELL WITH UPPER 60S TO NEAR 70 DEGREE DEWPOINTS ALONG A
PSEUDO WARM FRONT DEVELOPING IN THE COASTAL PLAIN. MESOANALYSIS
SHOWS MUCAPE VALUES 500-1000 J/KG ACROSS THE LOWER CSRA AND
SOUTHEAST MIDLANDS WHICH IS EXPECTED TO EXPAND NORTHWESTWARD
THROUGH THE EARLY EVENING. SUFFICIENT SHEAR IS IN PLACE WITH
35-40 KNOTS OF BULK SHEAR AND 0-3KM SRH AROUND 150-200 M2S2.
CURRENT RADAR SHOWS A LINE OF SOMEWHAT WEAKER CONVECTION MOVING
NORTHWESTWARD THROUGH THE FORECAST AREA BUT RELATIVELY LOW
TOPPED AND MOVING OUT OF THE BETTER INSTABILITY. EARLIER CELLS
DID EXHIBIT SOME BROAD ROTATION WHEN THEY WERE IN BARNWELL
COUNTY. SO AS MENTIONED ABOVE THERE IS A CONDITIONAL THREAT THAT
IF STRONGER STORMS CAN DEVELOP THEY WILL HAVE POTENTIAL TO
BECOME SEVERE GIVEN THE EVOLVING ENVIRONMENT AND IT WOULD LIKELY
BE ASSOCIATED WITH NEW CONVECTION THAT DEVELOPS LATER THIS
AFTERNOON INTO EARLY EVENING BUT THERE REMAINS UNCERTAINTY WITH
THAT.
KEY MESSAGE 2: A SEVERE WEATHER OUTBREAK IS POSSIBLE ON MONDAY,
WITH POTENTIAL FOR DESTRUCTIVE WIND GUSTS (75+ MPH) AND STRONG
TORNADOES (EF2+) AS A LINE OF STORMS PUSHES THROUGH THE AREA. A
MODERATE RISK (4/5) OF SEVERE WEATHER EXISTS FOR PART OF THE
AREA, WITH THE REST OF THE AREA IN AN ENHANCED RISK (3/5).
THERE IS NOT TOO MUCH CHANGE IN THE OVERALL THINKING REGARDING
POTENTIAL FOR A SEVERE WEATHER OUTBREAK ON MONDAY. SPC CONTINUES
TO HIGHLIGHT THE AREA IN A MODERATE RISK ACROSS THE NORTHERN
MIDLANDS AND PEE DEE AREA TO NEAR THE COLUMBIA METRO AREA WITH
AND ENHANCED RISK OF SEVERE WEATHER ELSEWHERE ACROSS THE
FORECAST AREA. A DYNAMIC AND DEEPENING 500MB TROUGH WILL BE
MOVING INTO THE GREAT LAKES AND MS VALLEY REGION BY 12Z MONDAY
WITH ADDITIONAL SHORTWAVE ENERGY AND A JET STREAK FURTHER
AMPLIFYING THE BASE OF THE TROUGH WHICH WILL INDUCE A NEGATIVE
TILT TO THE TROUGH DURING THE AFTERNOON HOURS ENHANCING THE
ALREADY STRONG UPPER FORCING. A STRONG COLD FRONT AND ASSOCIATED
QLCS LINE OF CONVECTION IS EXPECTED TO BE PUSHING INTO THE
SOUTHERN APPALACHIANS TO GULF COAST BY 12Z WITH A VERY
FAVORABLE DOWNSTREAM ENVIRONMENT CONDUCIVE FOR SEVERE WEATHER.
HI-RES SOUNDINGS AT 15Z ACROSS THE FORECAST AREA SHOW AN
ENVIRONMENT FEATURING MLCAPE VALUES APPROACHING 1000 J/KG, 0-6KM
BULK SHEAR OVER 40 KTS WITH PWATS NEAR 1.5 INCHES, STRONG LOW
LEVEL LAPSE RATES ASSOCIATED WITH THE HEIGHT FALLS AND A VEERING
HODOGRAPH WITH 0-3KM SRH VALUES AROUND 200 M2S2 AND STP VALUES
AROUND 1. HI-RES MODELS DEPICT A BROKEN QLCS LINE MOVING INTO
THE FORECAST AREA LATE MORNING AND CROSSING THROUGH THE
AFTERNOON HOURS WITH CONTINUED DESTABILIZATION EXPECTED AHEAD OF
THE LINE FAVORING POSSIBLE INTENSIFICATION AND THE HIGHEST
IMPACTS OCCURRING OVER THE PEE DEE AND EASTERN MIDLANDS. THE
ENVIRONMENT FAVORS EMBEDDED SUPERCELLS WITHIN THE QLCS LINE AND
ISOLATED DISCRETE SUPERCELLS DEVELOPING AHEAD OF THE LINE CANNOT
BE RULED OUT WHERE IF THEY MATERIALIZE WOULD PROVIDE A THREAT OF
STRONG TORNADOES. THE OVERALL TIMING OF THE LINE CROSSING THE
AREA APPEARS TO BE AROUND 10-11AM TO 4-5PM.
OUTSIDE OF THE CONVECTIVE WINDS THE GRADIENT WINDS WILL BE
STRONG DUE TO A VERY STRONG LOW LEVEL JET WITH 850MB WINDS 50-60
KNOTS WITH DEEP MIXING EXPECTED WHICH COULD RESULT IN NON-
CONVECTIVE GUSTS IN THE 40-50 MPH RANGE AHEAD OF THE FRONT AND
WITHIN THE STRONG COLD ADVECTION BEHIND THE FRONT. A WIND
ADVISORY WAS CONSIDERED AND AFTER COLLABORATION WITH NEIGHBORS
THE DECISION TO HOLD OFF WAS MADE TO ALLOW LATER SHIFTS TO RE-
EVALUATE THE NEED FOR ONE BUT IT IS VERY POSSIBLE ONE WILL BE
NEEDED.
KEY MESSAGE 3: SUBFREEZING TEMPERATURES POSSIBLE MULTIPLE NIGHTS
THIS WEEK. THERE IS POTENTIAL FOR A HARD FREEZE TUESDAY NIGHT INTO
EARLY WEDNESDAY.
NOT MUCH CHANGE IS SEEN IN THE OUTLOOK BEHIND MONDAY'S STRONG
FRONT AS MUCH COOLER AND DRIER AIR IS EXPECTED TO BUILD IN WITH
ROBUST CAA DRIVING TEMPERATURES FROM NEAR FREEZING TO SUB-
FREEZING. 850 MB TEMPERATURES FROM 18Z MONDAY TO 12Z TUESDAY
SHOULD DROP NEARLY 15 TO 20 DEGREES AND RAPID COOLING IS
EXPECTED AT THE SURFACE. THIS SHOULD AID IN BRINGING
TEMPERATURES BETWEEN 29-34F MONDAY NIGHT BUT WITH THE
COMPLICATION OF SURFACE WINDS REMAINING ELEVATED OVERNIGHT WITH
THE TIGHT PRESSURE GRADIENT FROM THE FRONT SLOWLY LOOSENING INTO
TUESDAY. THE MOST RECENT NBM IS FAIRLY SIMILAR TO ITS PREVIOUS
RUN, THOUGH THE EXPERIMENTAL NBM 5.0 IS 2-3 DEGREES WARMER THAN
THE DETERMINISTIC NBM. RECENT LREF PROBABILITIES FOR LOWS LESS
THAN 32F ARE AROUND 40-60%, HIGHEST NORTH OF I-20 AND THE NBM
REMAINS MORE AGGRESSIVE WITH A LARGE AREA OF PROBABILITIES
GREATER THAN 60% ALONG AND NORTH OF I-20. THE GREATER
UNCERTAINTY EXISTS MAINLY IN THE EASTERN MIDLANDS INTO THE PEE
DEE. WITH THE FAIRLY HIGH PROBABILITIES FOR TEMPERATURES NEAR TO
BELOW FREEZING, THE FREEZE WATCH REMAINS IN EFFECT MONDAY NIGHT
INTO TUESDAY MORNING FOR COUNTIES ALONG AND NORTH OF I-20,
THOUGH BURKE COUNTY GA AND BARNWELL COUNTY SC ARE INCLUDED IN
THIS WATCH AS WELL. TRENDS WILL CONTINUE TO BE MONITORED TO
DETERMINE IF A POTENTIAL EXPANSION IS NEEDED.
SURFACE HIGH PRESSURE BUILDS OVERHEAD ON TUESDAY, LIKELY
BRINGING THE COLDEST NIGHT OF THE WEEK TUESDAY NIGHT INTO
WEDNESDAY MORNING. NEAR IDEAL RADIATIONAL COOLING CONDITIONS
SHOULD YIELD TEMPERATURES INTO THE UPPER 20S FOR MUCH OF THE FA
WITH INCREASING POTENTIAL FOR A HARD FREEZE, ESPECIALLY ACROSS
THE NORTHERN MIDLANDS AND INTO THE PEE DEE REGION. ANOTHER NIGHT
WITH FREEZE PRODUCTS WILL LIKELY BE NEEDED WITH PROBABILITIES
FOR TEMPERATURES LESS THAN 32F OVER 60-80% FOR THE FA. MOISTURE
IS EXPECTED TO GRADUALLY INCREASE WEDNESDAY AS HIGH PRESSURE
DEPARTS AND THUS TEMPERATURES WARM A BIT. OVERNIGHT LOWS COULD
NEAR FREEZING AGAIN, BUT CONFIDENCE IN THIS IS NOT HIGH AT THE
MOMENT, THOUGH FROST PRODUCTS AT MINIMUM COULD BE NEEDED.
AVIATION /18Z SUNDAY THROUGH FRIDAY/
VFR CONDITIONS WITH PATCHY MVFR CEILINGS POSSIBLE THIS
AFTERNOON. ISOLATED TO SCATTERED SHOWERS AND STORMS POSSIBLE
THROUGH 21-00Z BEFORE CEILING RESTRICTIONS ARE POSSIBLE TONIGHT
INTO EARLY MONDAY MORNING.
CLOUD COVER CONTINUES TO INCREASE AS A BATCH OF SHOWERS AND A
COUPLE STORMS MAKE THEIR WAY NORTH FROM THE COAST. SOUTHEASTERLY
WINDS CONTINUE TO PICK UP TO AROUND 8-10 KTS AS WELL. DUE TO
THE PROGRESSION OF SHOWERS SOUTH OF THE TERMINALS, HAVE ADDED
VCSH TO ALL TAF SITES AND HAVE MAINTAINED THE TEMPO GROUP FOR
SHOWERS, THOUGH THIS MAY NEED TO BE UPDATED IF THUNDERSTORMS
DEVELOP THIS AFTERNOON. SOME SITES IN THE COASTAL PLAIN HAVE HAD
BRIEF PERIODS WITH MVFR CEILINGS AROUND 2500 FT, SO THESE WILL
BE POSSIBLE BRIEFLY THIS AFTERNOON BEFORE VFR CONDITIONS RETURN
THIS EVENING WITH SCT TO BKN MID LEVEL CLOUDS. TONIGHT, WINDS
SHIFT MORE SOUTHERLY SOUTH OF A LIFTING WARM FRONT AND INTENSIFY
FURTHER, BECOMING SUSTAINED AROUND 10-15 KTS WITH GUSTS UP TO
20-25 KTS POSSIBLE BY DAYBREAK ON MONDAY AHEAD OF A STRONG COLD
FRONT. VERY STRONG LOW LEVEL MOISTURE ADVECTION IS EXPECTED TO
BRING MVFR TO POSSIBLE IFR CEILINGS TONIGHT AFTER 07-09Z,
CONTINUING INTO MONDAY MORNING WITH INCREASING WINDS THROUGH THE
END OF THE PERIOD. AT THIS TIME, A LINE OF STRONG TO SEVERE
THUNDERSTORMS IS EXPECTED TO APPROACH THE TERMINALS FROM WEST TO
EAST (COLUMBIA AND AUGUSTA TERMINALS FIRST THEN OGB) AROUND
18Z, BUT POSSIBLY A BIT LATER, THUS HAVE LEFT MENTION OUT OF THE
TAF AT THIS TIME, BUT THE TIMING OF THESE STORMS SHOULD COME
INTO PICTURE A BIT MORE WITH THE NEXT TAF PERIOD.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS IN A LINE OF STRONG TO
SEVERE THUNDERSTORMS IS EXPECTED MONDAY AFTERNOON ALONG WITH
BREEZY WINDS. A RETURN TO VFR CONDITIONS IS THEN ANTICIPATED FOR
TUESDAY ONWARD.
CAE WATCHES/WARNINGS/ADVISORIES
SC...FREEZE WATCH FROM LATE MONDAY NIGHT THROUGH TUESDAY MORNING
FOR SCZ018-020>022-025>028-030-035-115-116.
GA...FREEZE WATCH FROM LATE MONDAY NIGHT THROUGH TUESDAY MORNING
FOR GAZ040-063>065-077.
DISCUSSION...23
AVIATION...CAL
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