769
FXUS62 KCAE 171925
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
325 PM EDT WED JUN 17 2026
WHAT HAS CHANGED
AN ISOLATED TORNADO RISK HAS BECOME A BIT MORE EVIDENT THURSDAY
EVENING INTO THE OVERNIGHT HOURS. CONFIDENCE IN HEAVY RAINFALL
POTENTIAL CONTINUES TO INCREASE. AVIATION DISCUSSION UPDATED FOR
18Z TAFS.
KEY MESSAGES
- 1. ACTIVE WEATHER INCREASINGLY LIKELY THURSDAY AFTERNOON INTO
FRIDAY AS A SYSTEM FROM THE GULF MOVES ACROSS THE REGION.
GUSTY WINDS, HEAVY RAINFALL, AND SEVERE WEATHER ARE POSSIBLE.
- 2. DRIER CONDITIONS RETURN THIS EVENING INTO EARLY THURSDAY
AHEAD OF THE ACTIVE WEATHER FROM KEY MESSAGE 1.
DISCUSSION
KEY MESSAGE 1: ACTIVE WEATHER INCREASINGLY LIKELY THURSDAY
AFTERNOON INTO FRIDAY AS A SYSTEM FROM THE GULF MOVES ACROSS THE
REGION. GUSTY WINDS, HEAVY RAINFALL, AND SEVERE WEATHER ARE
POSSIBLE.
OVERVIEW: ACTIVE WEATHER IS LIKELY STARTING THURSDAY AFTERNOON,
CONTINUING OVERNIGHT AND INTO FRIDAY AS THE REMNANTS OF WHAT IS
CURRENTLY TS ARTHUR MOVE INTO THE REGION. ARTHUR AND ITS
COUPLED UPPER WAVE CAN BE SEEN NEAR THE FAR SOUTHEAST TX COAST
AT THE MOMENT AND BOTH FEATURES SHOULD CONTINUE TO GRADUALLY
MOVE NORTHEASTWARD, MOVING INLAND (AND WEAKENING) INTO THE LOWER
MISSISSIPPI VALLEY TONIGHT. THROUGH THE DAY TOMORROW THE
REMNANT LOW LEVEL CIRCULATION OF ARTHUR AND UPPER WAVE SHOULD
CONTINUE DRIFTING NORTHEASTWARD, INCREASING DEEP MOISTURE ACROSS
THE FA WITH STRENGTHENING WIND FIELDS. A VERY MOIST AIRMASS BY
THE AFTERNOON HOURS SHOULD AID IN BRINGING SCATTERED SHOWER AND
THUNDERSTORM DEVELOPMENT WHERE A COUPLE STRONG TO SEVERE STORMS
CANNOT BE RULED OUT. THIS THREAT IS EXPECTED TO CONTINUE INTO
THE EVENING WHERE A LOW TORNADO RISK COULD DEVELOP MAINLY TOWARD
THE CSRA, BUT CONFIDENCE IN THIS RISK MATERIALIZING IS RATHER
LOW AT THE MOMENT. BY THE LATE EVENING HOURS THE BULK OF
MOISTURE IS EXPECTED TO OVERSPREAD THE CWA, WITH SCATTERED TO
WIDESPREAD SHOWERS AND STORMS MOVING IN, CONTINUING INTO FRIDAY
MORNING BEFORE COVERAGE MAY DECREASE A BIT. THE MAIN RISK
OVERNIGHT WILL BE THE HEAVY RAIN POTENTIAL WHERE PORTIONS OF THE CWA
ARE IN A SLIGHT RISK (LEVEL 2 OUT OF 4) FOR EXCESSIVE RAINFALL.
STRENGTHENING LOW LEVEL WIND FIELDS THURSDAY AFTERNOON AND A
TIGHTENING SURFACE PRESSURE GRADIENT SHOULD ALSO AID IN BRINGING
25-30 MPH WIND GUSTS, WHERE ISOLATED GUSTS TOWARD 35-45 MPH
CANNOT BE RULED OUT MAINLY LATE THURSDAY INTO THE OVERNIGHT
PERIOD. CONDITIONS ARE EXPECTED TO GRADUALLY IMPROVE FRIDAY
MORNING BEFORE A COLD FRONT PUSHES THROUGH DURING THE
AFTERNOON/EVENING WITH ADDITIONAL SHOWER AND STORM CHANCES THAT
END BY THE LATE EVENING.
HEAVY RAINFALL: THE PRIMARY THREAT FROM THIS SYSTEM WILL BE THE
HEAVY RAINFALL POTENTIAL AS VERY EFFICIENT RAIN RATES ARE
LIKELY, ESPECIALLY THURSDAY EVENING AND OVERNIGHT INTO FRIDAY.
AS THE REMNANTS OF ARTHUR NEAR, PWAT'S ARE EXPECTED TO INCREASE
TOWARD 2" BY THE EARLY AFTERNOON, BEFORE SURGING TOWARD
2.20-2.40" DURING THE EVENING AND OVERNIGHT PERIOD. AS THIS
MOISTURE INCREASES WITH THE APPROACHING UPPER WAVE AND REMNANT
LOW LEVEL CIRCULATION, IVT VALUES REACH TOWARD THE NAEFS 99TH TO
99.5TH PERCENTILE. THIS IS MOSTLY THANKS TO A SLIGHT SHIFT IN A
FEW HIGH-RES AND GLOBAL MODELS KEEPING THE LOW TO MID LEVEL
CORE OF THE SYSTEM A BIT MORE INTACT, LEADING TO A 35-55 KT LLJ
OVERSPREADING THE AREA THURSDAY EVENING AND OVERNIGHT. THIS
INCREASING LLJ COUPLED WITH THE AFOREMENTIONED PWAT'S, WARM
CLOUD LAYER DEPTHS EXCEEDING 14,000 FT, AND ELEVATED INSTABILITY
SETS THE STAGE FOR EFFICIENT RAIN RATES. IN TERMS OF TOTALS,
THE LATEST MEAN HREF AND REFS SOLUTIONS SUPPORT A WIDESPREAD
0.75-1.25" ACROSS THE FA, HIGHEST IN THE CSRA. WHEN TAKING A
LOOK AT THE LPMM PRODUCT FROM EACH SUITE AND INDIVIDUAL 12Z
CAM'S SPOTS OF 2-3.5" ARE SEEN WHERE TRAINING OCCURS WITH THE
EXPECTED RATES. THIS SEEMS REASONABLE CONSIDERING THE LLJ MAY
ENHANCE THE EFFICIENCY OF THIS RAINFALL MORE THAT PREVIOUSLY
DISCUSSED. DECIDED TO HOLD OFF ON A FLOOD WATCH AT THE MOMENT AS
CONFIDENCE IN THESE HIGHER AMOUNTS BECOMING WIDESPREAD REMAINS
LOW WITH MODEL TO MODEL VARIANCE, BUT AREAS SOUTH OF THE PEE DEE
ARE OUTLINED IN A SLIGHT RISK (LEVEL 2 OUT OF 4) FOR EXCESSIVE
RAINFALL, MEANING ISOLATED FLASH FLOODING COULD BE POSSIBLE,
MAINLY THURSDAY EVENING INTO EARLY FRIDAY MORNING.
SEVERE WEATHER: THE WHOLE FA IS OUTLINED IN SPC'S MARGINAL RISK
(LEVEL L OUT OF 5) FOR SEVERE WEATHER THURSDAY. AT LEAST MODEST
HEATING IN AN INCREASINGLY MOIST AIRMASS IS EXPECTED TO YIELD
MLCAPE VALUES NEAR 1200-1700 J/KG WITH INCREASING DEEP LAYER
SHEAR AS THE REMNANT SURFACE CIRCULATION AND UPPER WAVE NEAR.
INCREASED MIXING IN THE AFTERNOON ALSO IS EXPECTED TO YIELD
DCAPE VALUES NEAR 700-1000 J/KG WITH TEI VALUES NEARING 25.
ISOLATED TO SCATTERED STORMS IN THE AFTERNOON ARE EXPECTED TO
BRING THE MAIN RISK OF STRONG TO DAMAGING WIND GUSTS FROM PRECIP
LOADED DOWNDRAFTS, BUT ALSO FROM POSSIBLE COLD POOL
CONSOLIDATION IN ANY CLUSTER. THE MAIN CHANGE TO THE SEVERE
THREAT IS A LOW END TORNADO RISK THAT MAY DEVELOP MAINLY NEAR
THE CSRA DURING THE EVENING INTO THE EARLY OVERNIGHT HOURS. NEAR
SURFACE WINDS ARE EXPECTED TO BACK A BIT AS THE REMNANT SURFACE
CIRCULATION NEARS AND THE AFOREMENTIONED LLJ MOVES IN. MODELED
SOUNDINGS INDICATE 0-1KM BULK SHEAR SHOULD INCREASE TOWARD 25-30
KTS DURING THE EVENING WITH 0-1KM SRH NEARING 125-180 M^2/S^2
AND THIS IS FURTHER SUPPORTED IN THE 12Z MEAN HREF SOLUTION.
THIS RISK IS CONDITIONAL HOWEVER ON THE AMOUNT OF LOW LEVEL
INSTABILITY THAT CAN REMAIN IN PLACE DURING THE EVENING. THE
SEVERE WEATHER RISK IS EXPECTED TO GRADUALLY DIMINISH OVERNIGHT
WITH THE PROBABILITY FOR CONVECTION TO BECOME ELEVATED
INCREASING.
WIND GUSTS: AS MENTIONED IN THE OVERVIEW, INCREASING WIND
PROFILES WITH A TIGHTENING SURFACE PRESSURE GRADIENT ARE
EXPECTED TO YIELD WIND GUSTS TO 25-30 MPH THROUGH THE AFTERNOON
AND INTO THE EVENING HOURS THURSDAY. THE MAIN TALKING POINT HERE
COMES LATE THURSDAY EVENING AND OVERNIGHT INTO EARLY FRIDAY.
WITH THE THE SLIGHT SHIFT IN MODEL GUIDANCE IN KEEPING THE CORE
OF THE SYSTEM A BIT MORE INTACT, THERE HAVE BEEN MORE
DETERMINISTIC RUNS SHOWING THE POTENTIAL FOR ISOLATED 35-45 MPH
GUSTS AS THE ROBUST LLJ SHIFTS OVERHEAD. 12Z HREF PROBABILITIES
FOR GUSTS GREATER THAN 40 MPH ARE NOW NEAR 20-40%, MAINLY TOWARD
THE CSRA AND INTO THE PARTS OF CENTRAL/EASTERN MIDLANDS.
CONFIDENCE IN THESE STRONGER GUSTS IS PRETTY LOW AS THE
OVERNIGHT/EARLY MORNING PERIOD FAVORS LESS MIXING OCCURRING AS
SEEN IN BUFKIT SOUNDINGS. THERE IS ALSO A GENEROUS SPREAD ACROSS
HIGH-RES MODELS ON THIS POTENTIAL STILL. OVERALL, THE POTENTIAL
FOR THESE STRONGER GUSTS IS THERE BUT CONFIDENCE REMAINS LOW,
WILL NEED TO CONTINUE TO EVALUATE THIS THREAT OVERNIGHT TONIGHT
AND EARLY TOMORROW.
KEY MESSAGE 2: DRIER CONDITIONS RETURN THIS EVENING INTO EARLY THURSDAY
AHEAD OF THE ACTIVE WEATHER FROM KEY MESSAGE 1.
THE SHORTWAVE THAT BROUGHT SHOWERS ACROSS THE AREA THIS MORNING
IS PUSHING OFF THE COAST, LEADING TO DECREASING COVERAGE ACROSS
THE FA. A COUPLE ISOLATED TO SCATTERED SHOWERS AND STORMS WILL
REMAIN POSSIBLE TOWARD THE CSRA AND SOUTHEASTERN MIDLANDS INTO
THE EARLY EVENING, BUT DRY CONDITIONS ARE THEN EXPECTED TO TAKE
HOLD TONIGHT INTO EARLY THURSDAY BEFORE ACTIVE WEATHER MOVES IN
LATER THURSDAY (SEE KEY MESSAGE 1 FOR THESE DETAILS). AS CLOUD
COVER BREAKS UP A BIT THIS AFTERNOON TEMPERATURES SHOULD REACH
INTO THE MID TO UPPER 80S BEFORE WARMING A BIT THURSDAY, TOWARD
THE UPPER 80S TO LOW 90S.
AVIATION /19Z WEDNESDAY THROUGH MONDAY/
VFR CONDITIONS FOR THE REST OF THE DAY WITH RESTRICTIONS
POSSIBLE NEAR DAYBREAK TOMORROW.
DRIER AIR SHIFTED INTO THE AREA THIS AFTERNOON WHICH LED TO
RESTRICTIONS DIMINISHING, ALTHOUGH ISOLATED MVFR CEILINGS
POSSIBLE AT THE SOUTHERN TERMINALS FOR THE NEXT HOUR OR SO.
MOISTURE WILL RETURN TOMORROW WITH STRENGTHENING SOUTHWESTERLY
FLOW WITH RESTRICTIONS POSSIBLE NEAR DAYBREAK WITH HIGHEST
PROBABILITY IN THE AUGUSTA/AIKEN/ORANGEBURG TERMINALS. WHILE
THERE REMAINS A BRIEF CHANCE OF IFR CEILINGS, HAVE LEFT AT THE
MENTION WITH LIMITED CONFIDENCE AT THIS POINT. CONVECTION
INITIATION TOMORROW APPEARS TO GENERALLY BE AFTER 18Z SO HAVE
LEFT OUT ANY TSRA AS WELL. WINDS WILL REMAIN BREEZY GENERALLY
OUT OF THE SOUTHWEST WITH GUSTS UP TO 20 KNOTS POSSIBLE,
GENERALLY DURING THE DAYTIME HOURS.
EXTENDED AVIATION OUTLOOK...DIURNALLY FAVORED CONVECTION
POSSIBLE EACH AFTERNOON, FAVORING THE SOUTHERN MIDLANDS AND
CSRA. BREEZY CONDITIONS EXPECTED THU/FRI WITH INCREASED CHANCES
OF RAIN AS A GULF COAST SYSTEM APPROACHES THE AREA.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
DISCUSSION...DH
AVIATION...96
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page