600
FXUS62 KCAE 202352
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
752 PM EDT MON JUL 20 2026
WHAT HAS CHANGED
UPDATED KEY MESSAGE #1. AVIATION DISCUSSION UPDATED FOR 00Z
TAFS.
KEY MESSAGES
- 1. ISOLATED TO WIDELY SCATTERED CONVECTION OVER THE COMING
HOURS AND AGAIN ON TUESDAY WITH HOT/HUMID CONDITIONS
CONTINUING.
- 2. RAIN CHANCES INCREASE WEDNESDAY AND REMAIN HIGH THROUGH THE
WEEKEND. SEVERE WEATHER WILL BE POSSIBLE ON WED AND THU.
DISCUSSION
KEY MESSAGE 1: ISOLATED TO WIDELY SCATTERED CONVECTION OVER THE
COMING HOURS AND AGAIN ON TUESDAY WITH HOT/HUMID CONDITIONS
CONTINUING.
THIS EVENING: A COUPLE SHOWERS ARE SEEN IN THE CSRA AND
SOUTHEASTERN MIDLANDS AS MLCAPE VALUES NOW SIT AROUND 2000 J/KG.
CANNOT RULE OUT AN ISOLATED STORM OVER THE NEXT 2-3 HOURS, BUT
ANY ACTIVITY IS EXPECTED TO REMAIN FAIRLY SPOTTY AND THE RISK
FOR ANY STRONG STORM IS LOW. DRY CONDITIONS ARE THEN EXPECTED
TONIGHT.
TUESDAY: AS THE GULF SYSTEM DRIFTS SLIGHTLY WESTWARD, MODELS
PROJECT A DRY SLOT OF AIR ADVECTING UP INTO THE FORECAST AREA
DURING THE DAY ON TUESDAY. PWAT VALUES AROUND 1.5 INCHES OVER
MUCH OF THE AREA SHOULD LIMIT THE EXTENT OF CONVECTIVE
DEVELOPMENT. THAT SAID WE COULD SEE A FEW ISOLATED
THUNDERSTORMS, PARTICULARLY ALONG THE SEA BREEZE TUESDAY
AFTERNOON. THE THREATS OF SEVERE WEATHER AND HEAVY RAIN ARE
LOW. THE DRIER AIR MASS SHOULD ALSO ALLOW DEWPOINTS TO MIX INTO
THE 60S REDUCING THE CHANCES OF MEETING HEAT ADVISORY CONDITIONS
DESPITE HIGHS MAINLY IN THE MID 90S.
KEY MESSAGE 2: RAIN CHANCES INCREASE WEDNESDAY AND REMAIN HIGH
THROUGH THE WEEKEND. SEVERE WEATHER WILL BE POSSIBLE ON WED AND
THU.
THE OVERALL SYNOPTIC PATTERN REMAINS UNCHANGED IN GLOBAL
ENSEMBLES FOR LATER THIS WEEK AND THE WEEKEND. A STRONG UPPER
LEVEL TROUGH WILL LIKELY EXTEND FROM THE EASTERN GREAT LAKES
DOWN INTO THE MID-ATLANTIC. THE ASSOCIATED COLD FRONT WILL DIVE
DOWN INTO THE MID-ATLANTIC AND COULD NEAR THE FA WEDNESDAY
THROUGH THURSDAY. IVT VALUES FROM THE NAEFS AHEAD OF THE FRONT
ARE NEAR THE 90TH TO 99TH PERCENTILE OF CLIMATOLOGY. THERE
REMAINS SOME UNCERTAINTY IN THE DEPTH OF THE UPPER TROUGH AND
HOW FAR SOUTH THE FRONT WILL PUSH BUT ON AVERAGE THE FRONT IS
EXPECTED TO GET NEAR ENOUGH TO THE FA TO SUPPORT WIDESPREAD
SHOWERS AND THUNDERSTORMS LATE WEDNESDAY AND THURSDAY.
SEASONABLE INSTABILITY AND MODERATE DEEP LAYER SHEAR SHOULD
SUPPORT SOMEWHAT ORGANIZED THUNDERSTORMS AND POSSIBLY SEVERE
WEATHER.
GLOBAL MODELS DEPICT THE FRONTAL BOUNDARY STALLING NEAR OR OVER
THE FA ON THURSDAY AS A SHORTWAVE PASSES. CONTINUED MOISTURE
ADVECTION INTO THE REGION, AND CONVERGENCE ALONG THE FRONT
SUPPORTS WIDESPREAD THUNDERSTORM CHANCES WITH HEAVY RAINFALL
POSSIBLE. WITH THE REGION REMAINING IN NORTHWEST FLOW INTO THE
WEEKEND, A SERIES OF SHORTWAVES ARE EXPECTED TO CONTINUE PUSHING
THROUGH, ENHANCING CONVECTIVE DEVELOPMENT POTENTIALLY OUTSIDE
OF TYPICAL DIURNAL HOURS.
AVIATION /00Z TUESDAY THROUGH SATURDAY/
VFR CONDITIONS EXPECTED OUTSIDE OF ISOLATED CONVECTION.
SEVERAL OUTFLOW BOUNDARIES FROM EARLIER CONVECTION HAVE BEEN
PUSHING THROUGH THE CENTRAL MIDLANDS AND INTO THE CSRA EARLY
THIS EVENING. THESE ARE CURRENTLY ON THE DRY SIDE, BUT CAN NOT
RULE OUT AN ISOLATED SHOWER UNTIL SUNSET. IN ADDITION, SOME
SHOWER ACTIVITY POSSIBLE AS SHOWERS MOVING THROUGH EASTERN GA
TRACK NORTHWARD TOWARDS THE CSRA. WILL HANDLE CSRA WITH A TEMPO
THROUGH 02Z FOR MVFR VISIBILITIES IN - TSRA WITH VCSH ALSO
MENTIONED. MAY NEED TO EXTEND IF THE EASTERN GA ACTIVITY HOLDS
TOGETHER THE NEXT FEW HOURS AS IT MOVES NORTHWARDS. ACROSS THE
CENTRAL MIDLANDS, ISOLATED SHOWER/STORM ACTIVITY NOT ENTIRELY
OUT OF THE QUESTION, BUT WILL HOLD OFF ON MENTION AT THIS TIME
DUE TO LOWER CONFIDENCE. AFTER 06Z ALL SITES WILL REMAIN VFR,
WITH A DRY FORECAST OVERNIGHT AND INTO TUESDAY. WINDS WILL
REMAIN SOUTHERLY BETWEEN 5-10 KTS THROUGH SUNSET, THEN DROP TO
AROUND 5 KNOTS OVERNIGHT. STRONGER AND GUSTIER WINDS WILL TAKE
HOLD OUT OF THE SOUTH AFTER 15Z TUESDAY, WITH GUSTS OVER 20 KTS
POSSIBLE AFTER 18Z AT ALL SITES.
EXTENDED AVIATION OUTLOOK...POTENTIAL FOR RESTRICTIONS FROM
SHOWERS AND THUNDERSTORMS CONTINUES WITH THE THREAT INCREASING
FOR THE MID TO LATE WEEK PERIOD.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
DISCUSSION...DH/CJR
AVIATION...73
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