676
FXUS62 KCAE 210548
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
148 AM EDT MON SEP 21 2026
WHAT HAS CHANGED
SPOTTY SHOWERS REMAIN POSSIBLE THIS AFTERNOON, WHILE COLD AIR
DAMMING IS INCREASINGLY LIKELY MIDWEEK. AVIATION DISCUSSION
UPDATED FOR 06Z TAFS.
KEY MESSAGES
- 1. ABOVE AVERAGE TEMPERATURES AND INCREASED CHANCES FOR
SHOWERS AND STORMS CONTINUE THROUGH TUESDAY.
- 2. RAIN EXPECTED ON WEDNESDAY, WITH COOLER AND DRIER
CONDITIONS LIKELY BY LATE WEEK AND NEXT WEEKEND.
DISCUSSION
KEY MESSAGE 1: ABOVE AVERAGE TEMPERATURES AND INCREASED CHANCES
FOR SHOWERS AND STORMS CONTINUE THROUGH TUESDAY.
THE OVERALL PATTERN BEGINS TO SHIFT EARLY THIS WEEK, AS THE
DOMINANT RIDGING THAT HAS PREVAILED GRADUALLY BREAKS DOWN AND
GIVES WAY TO TROUGHING BY MIDWEEK. IN THE MEANTIME, TODAY WILL
REMAIN SEASONABLY HOT AND HUMID, WITH TUESDAY LIKELY TO CONTINUE
RUNNING ABOVE AVERAGE AS HIGHS REACH THE LOW TO MID 90S. A FEW
POP- UP SHOWERS COULD DEVELOP LATER THIS AFTERNOON, WITH
SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED TO BECOME MORE
WIDESPREAD TUESDAY. COVERAGE SHOULD INCREASE THROUGH TUESDAY
AFTERNOON AND EVENING AS FORCING IMPROVES, WITH A STRONG
SURFACE HIGH BUILDING ACROSS SOUTHEASTERN CANADA HELPING TO
DRIVE A BACKDOOR FRONT SOUTHWARD INTO THE AREA INTO WEDNESDAY.
THIS WILL MARK THE BEGINNING OF A TRANSITION TOWARD A COOLER AND
DRIER PATTERN BY MID TO LATE WEEK.
KEY MESSAGE 2: RAIN EXPECTED ON WEDNESDAY, WITH COOLER AND
DRIER CONDITIONS LIKELY BY LATE WEEK AND NEXT WEEKEND.
ENSEMBLE AND OPERATIONAL GUIDANCE ARE FINALLY SHOWING A
FAVORABLE PATTERN FOR MORE REASONABLE, FALL-LIKE TEMPERATURES
ACROSS OUR AREA BEGINNING WEDNESDAY. SOME UNCERTAINTY REMAINS AS
A BLOCKING PATTERN ACROSS THE NORTHERN PLAINS SHIFTS EASTWARD.
PATTERN CHANGES OF THIS MAGNITUDE OFTEN PRODUCE UNCERTAINTY
REGARDING THE EVENTUAL PLACEMENT AND EVOLUTION OF THE UPPER-
LEVEL AND SURFACE LOWS. REGARDLESS, GUIDANCE INCREASINGLY
SUPPORTS THE DEVELOPMENT OF A WEDGE BEHIND THE FRONT SOMETIME
WEDNESDAY. THE NAM REMAINS THE MOST AGGRESSIVE, BRINGING THE
FRONT SOUTH OF THE AREA BY WEDNESDAY AFTERNOON. THIS SCENARIO
APPEARS SOMEWHAT UNLIKELY AT THIS TIME, BUT THERE REMAINS A
RELATIVELY HIGH BUST POTENTIAL FOR TEMPERATURES WEDNESDAY
AFTERNOON AS THE EXACT POSITION AND TIMING OF THE FRONT WILL
HAVE A SIGNIFICANT IMPACT ON TEMPERATURES ACROSS THE AREA.
BEYOND THAT, THE FORECAST INCREASINGLY TRENDS TOWARD MORE
PLEASANT CONDITIONS. GUIDANCE IS IN GOOD AGREEMENT THAT DEEP
TROUGHING WILL BECOME ESTABLISHED ACROSS THE EASTERN CONUS,
RESULTING IN NORTHWESTERLY FLOW AND DRY AIR ACROSS THE REGION
FROM THURSDAY INTO THE WEEKEND. HIGHS SHOULD GENERALLY FALL INTO
THE UPPER 70S AND LOW 80S, WITH OVERNIGHT LOWS IN THE UPPER 50S
TO LOW 60S. OVERALL, THIS SHOULD PROVIDE OUR FIRST REAL TASTE
OF FALL WITH A REFRESHING CHANGE IN TEMPERATURES ARRIVING JUST
AS ASTRONOMICAL AUTUMN BEGINS ON TUESDAY!
AVIATION /06Z MONDAY THROUGH FRIDAY/
PATCHY FG AND AREAS OF BR POSSIBLE TONIGHT. FG MOST LIKELY AT
AGS AND OGB.
SATELLITE NOW SHOWING MAINLY THIN CIRRUS ACROSS THE MAJORITY OF
THE AREA. WITH NEARLY CALM WINDS, AREAS THAT CAN COMPLETELY
CLEAR OUT BY MORNING SHOULD FAVOR FOG DEVELOPMENT AROUND SUNRISE.
MODELS HAVE BEEN SOMEWHAT CONSISTENT FAVORING IFR RESTRICTIONS
AT FOG PRONE AGS AND OGB, AS WELL AS AIK. MVFR VISIBILITY
RESTRICTIONS ARE MORE LIKELY AT THE OTHER SITES. IT REMAINS TO
BE SEEN WHETHER RESTRICTIONS WILL BE LIMITED TO RIGHT AROUND
SUNRISE OR MORE PERSISTENT, SO FOR NOW HAVE CONTINUED THE TEMPO
GROUPS AT ALL SITES. RESTRICTIONS SHOULD LIFT BY 14 OR 15Z.
ISOLATED THUNDERSTORMS ARE POSSIBLE AGAIN DURING THE AFTERNOON,
HOWEVER COVERAGE IS EXPECTED TO BE TOO LOW TO BE INCLUDED IN THE
TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...RAIN CHANCES AND WIDESPREAD
RESTRICTIONS ARE MOST LIKELY TUESDAY THROUGH THURSDAY AS
MOISTURE ADVECTION INCREASES AND WEDGE CONDITIONS DEVELOP.
SEASONAL, EARLY MORNING CIG/VIS RESTRICTIONS WILL REMAIN
POSSIBLE EARLY THIS WEEK.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
DISCUSSION...ND
AVIATION...73
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