620
FXUS62 KCAE 111712
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
112 PM EDT FRI SEP 11 2026
WHAT HAS CHANGED
TWEAKS TO FRIDAY-SATURDAY FORECAST DISCUSSION AND 18Z AVIATION
UPDATES.
KEY MESSAGES
- 1. ABOVE NORMAL TEMPERATURES LAST INTO NEXT WEEK WITH
INCREASING CHANCES FOR SHOWERS AND STORMS TODAY-SATURDAY.
DISCUSSION
KEY MESSAGE 1: ABOVE NORMAL TEMPERATURES LAST INTO NEXT WEEK WITH
INCREASING CHANCES FOR SHOWERS AND STORMS TODAY-SATURDAY.
A SLOW MOVING TROUGH IN THE CENTRAL CONUS IS FORECAST TO
CONTINUE APPROACHING THE AREA FROM THE WEST, WITH RICH MOISTURE
ADVECTING NORTHWARD INTO THE FA AS A RESULT. PWS ARE NEAR 2"
ALREADY, WITH >2" PWS EXPECTED INTO SATURDAY. WITH CONVECTIVE
TEMPS FORECAST IN THE UPPER 80S AND LOWER 90S BOTH DAYS, ALONG
WITH THE MODEST FORCING FROM THE APPROACHING SHORTWAVE AND
PLENTY OF INSTABILITY, SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ARE LIKELY BOTH THIS AFTERNOON AND SATURDAY
AFTERNOON. THE MOISTURE RICH PROFILE SHOULD KEEP THE SEVERE
THREAT RELATIVELY AT BAY ACROSS THE AREA. DCAPE AND TEI VALUES
ARE PRETTY LOW FOR STRONG DOWNBURSTS BOTH DAYS, WITH PRECIP
LOADING THE LIKELY CULPRIT FOR ANY STRONGER STORMS. SBCAPE
VALUES DO LOOK QUITE HIGH THIS AFTERNOON, SO TODAY IS PROBABLY
THE BETTER OF THE TWO DAYS FOR ANY STRONG TO SEVERE CONVECTION;
12Z HRRR-REFS-HREF SUITES SUPPORT MORE ROBUST CONVECTION INTO
THE MIDLANDS FRIDAY, BUT LIKELY ARE TOO SLOW FOR INITIATION.
MUCH THE SAME IS EXPECTED FOR SATURDAY BUT THE AXIS WILL SHIFT
MORE INTO THE UPSTATE AND WESTERN MIDLANDS WITH BETTER FORCING
AND MOISTURE CONVERGENCE. HIGHS BOTH DAYS ARE EXPECTED TO BE
MODULATED BY CONVECTIVE COVERAGE.
BEGINNING SUNDAY, A RIDGE ALOFT IS FORECAST TO BEGIN BUILDING
EASTWARD AND SHIFTING THE TROUGH AXIS TO OUR EAST. PRECIP
CHANCES ARE EXPECTED TO DIMINISH AS A RESULT, WITH ONLY
ISOLATED TO SCATTERED COVERAGE EXPECTED. THE RIDGE IS THEN
FORECAST TO CONTINUE BUILDING INTO THE REGION THROUGH MUCH OF
NEXT WEEK, WITH EXTREME 500 HPA HEIGHTS (NAEFS FORECAST MAX
HEIGHTS IN THE SEPTEMBER 1979-2009 CLIMATOLOGY!) SET UP ACROSS
THE REGION. ONE OF THE INTERESTING THINGS THAT MAY RESULT FROM
THE INTENSITY OF THE RIDGE IS A SERIES OF STRONG TROUGHS PUSHING
EASTWARD ATOP IT INTO THE NORTHEASTERN CONUS. TYPICALLY, THIS
WOULDN'T MEAN A TON CONSIDERING THE ROBUSTNESS OF THIS UPPER
RIDGE. HOWEVER, STRONG CONVERGENCE ON THE BACKSIDES OF THESE
TROUGHS IS FORECAST TO YIELD AN ANOMALOUS SURFACE HIGH SETTLING
INTO THE NORTHEAST AND MID-ATLANTIC BY TUESDAY, PUSHING A
BACKDOOR FRONT THROUGH THE AREA MONDAY NIGHT. SO MONDAY, AHEAD
OF SAID FRONT, WILL LIKELY BE WARM AS WE GET THE COMBINATION OF
RISING HEIGHTS AND COMPRESSIONAL HEATING AHEAD OF AN APPROACHING
FRONT. BUT BEHIND THAT FRONT, WHILE TEMPS DON'T LOOK COOL BY
ANY STRETCH, THEY LIKELY WON'T BE PARTICULARLY HOT EITHER WITH
RESPECT TO HOW STRONG THE RIDGE WILL BE. SURFACE DEWPOINTS ALSO
LOOK TO DROP, HELPING MAKE THE AIRMASS MORE PALATABLE. SO THIS
BACKDOOR FRONT WILL LIKELY HELP STEM THE TIDE OF THE ROBUST
500MB HEIGHTS AND KEEP TEMPS FROM APPROACHING RECORDS.
AVIATION /18Z FRIDAY THROUGH TUESDAY/
ISOLATED TO SCATTERED CONVECTION EXPECTED THIS AFTERNOON. BRIEF
RESTRICTIONS POSSIBLE AGAIN EARLY SATURDAY.
VFR CONDITIONS ARE SEEN EARLY THIS AFTERNOON WITH LIGHT
SOUTHERLY TO SOUTHWESTERLY WINDS. AS A CUMULUS DECK CONTINUES TO
GROW, SCATTERED CONVECTION IS SEEN DEVELOPING IN PORTIONS OF THE
CSRA AND SOUTHEASTERN MIDLANDS. THIS ACTIVITY IS EXPECTED TO
CONTINUE THROUGH THE AFTERNOON, POSSIBLY EXPANDING NORTHWARD.
DUE TO THIS, HAVE A MIX OF TEMPO OR PROB30 GROUPS FOR
RESTRICTIONS DUE TO CONVECTION WITH THE HIGHEST PROBABILITIES
CURRENTLY NEAR OGB/AGS/DNL WHERE STORMS ARE ALREADY DEVELOPING.
THIS ACTIVITY IS EXPECTED TO WIND DOWN DURING THE EVENING WITH
LINGERING DEBRIS CLOUDINESS LIKELY AS WINDS BECOME LIGHT AND
VARIABLE. THERE IS GENEROUS SPREAD ACROSS MODEL GUIDANCE
REGARDING THE DEVELOPMENT OF FOG/STRATUS TONIGHT, BUT WITH
PLENTIFUL LOW LEVEL MOISTURE IN PLACE, AND RECENT RAINFALL,
CURRENT THINKING IS AT LEAST PATCHY VSBY/CIG RESTRICTIONS COULD
BE POSSIBLE EARLY SATURDAY MORNING, WITH GREATER CHANCES NEAR
OGB. AS ANY STRATUS LIFTS THROUGH THE MORNING, MVFR CEILINGS
COULD BE SEEN BEFORE GIVING WAY TO VFR CUMULUS NEAR THE END OF
THE TAF PERIOD. WINDS SHOULD PICK BACK UP OUT OF THE SOUTH-
SOUTHWEST, REMAINING LIGHT BY THE LATE MORNING. ANOTHER ROUND OF
CONVECTION WILL BE POSSIBLE AFTER THIS TAF PERIOD.
EXTENDED AVIATION OUTLOOK...THE HIGHEST RAIN CHANCES WILL BE
SATURDAY AFTERNOON WITH WIDESPREAD THUNDERSTORMS EXPECTED. THE
PROBABILITY FOR EARLY MORNING FOG/STRATUS INCREASES THIS WEEKEND
AND EARLY NEXT WEEK.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
DISCUSSION...42
AVIATION...DH
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