222
FXUS62 KCAE 301845
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
245 PM EDT WED SEP 30 2026
WHAT HAS CHANGED
LOWERED TEMPERATURES SATURDAY WITH POTENTIAL FOR CAD DEVELOPING
ESPECIALLY IN THE NORTHWESTERN PORTION OF THE AREA. AVIATION
DISCUSSION UPDATED FOR 18Z TAFS.
KEY MESSAGES
- 1. DRY CONDITIONS WITH ABOVE NORMAL TEMPERATURES ARE EXPECTED
THROUGH FRIDAY.
- 2. INCREASING CHANCES FOR RAIN ASSOCIATED WITH A FRONT
APPROACHING THIS WEEKEND.
DISCUSSION
KEY MESSAGE 1: DRY CONDITIONS WITH ABOVE NORMAL TEMPERATURES
ARE EXPECTED THROUGH FRIDAY.
UPPER LEVEL RIDGE AXIS REMAINS TO THE WEST OF THE AREA AND WILL
GRADUALLY SHIFT EASTWARD TOWARDS THE END OF THE WEEK LEADING TO
ABOVE AVERAGE TEMPERATURES AS 500 MB HEIGHTS WILL RISE TO NEAR
1.5 TO 2 STANDARD DEVIATIONS ABOVE NORMAL BASED ON ENSEMBLE
MEANS. THIS WILL LIKELY LEAD TO HIGHS NEARLY 10 DEGREES ABOVE
NORMAL, IN THE LOW 90S AS OCTOBER BEGINS UNSEASONABLE WARM. WITH
SURFACE HIGH PRESSURE SHIFTING OFFSHORE, LOW LEVEL MOISTURE
WILL GRADUALLY INCREASE, ALTHOUGH FORECAST SOUNDINGS INDICATE A
LAYER OF SUBSTANTIAL DRY AIR IN PLACE THAT WILL PRECLUDE ANY
RAIN TODAY AND TOMORROW. WHILE DEEP LAYER MOISTURE BEGINS TO
INCREASE FRIDAY WITH SOUTHWESTERLY FLOW BEGINNING TO DEVELOP,
THERE WILL BE A SUBSTANTIAL PWAT GRADIENT ACROSS THE AREA. WHILE
AN ISOLATED SHOWER OR THUNDERSTORM REMAINS POSSIBLE IN THE FAR
SOUTHERN AREA WHERE MOISTURE INCREASES FASTEST, MOST OF THE AREA
EXPECTED TO REMAIN DRY FRIDAY.
KEY MESSAGE 2: INCREASING CHANCES FOR RAIN ASSOCIATED WITH A FRONT
APPROACHING THIS WEEKEND.
GUIDANCE APPEARS TO CONTINUE TO CONVERGE ON A GENERALLY SLOWER
SOLUTION WITH THE ARRIVAL AND PROGRESSION OF THE FRONT THROUGH
THE AREA THIS WEEKEND WITH ENSEMBLE MEANS INDICATING PWATS RISE
TO ABOVE 150-200 PERCENT OF NORMAL SATURDAY AND CONTINUING
THROUGH SUNDAY. AS WE ENTER THE MEDIUM RANGE, GUIDANCE IS
FAVORING COLD AIR DAMMING DEVELOPING SATURDAY, ESPECIALLY IN THE
UPSTATE SO HAVE GENERALLY LOWERED MAX TEMPERATURES IN THE
NORTHWEST, ALTHOUGH THERE IS POTENTIAL FOR A SUBSTANTIAL
TEMPERATURE GRADIENT OVER THE AREA FROM NORTHWEST TO SOUTHEAST.
WHILE FORCING WILL BE LIMITED, ESPECIALLY EARLY, ISENTROPIC LIFT
WILL LEAD TO DEVELOPING RAIN OVER THE AREA WITH HIGHEST CHANCE
FOR STORMS IN THE SOUTHEAST. STRONGER FORCING LIKELY LATE
SATURDAY INTO SUNDAY WHICH MAY LEAD TO HEAVIER RAIN. COLD AIR
DAMMING LIKELY LINGERS INTO SUNDAY AND WHILE BLENDED GUIDANCE
FAVORS MUCH COOLER TEMPERATURES, THERE STILL REMAINS THE
POSSIBILITY THAT THEY ARE TOO HIGH, ESPECIALLY IN THE NORTHWEST.
DRIER AIR LIKELY FILTERS INTO THE AREA MONDAY AS THE FRONT IS
PUSHED SOUTHEAST WITH A DEEPENING TROUGH MOVING INTO THE GREAT
LAKES. LREF CONTINUES TO INCREASE PROBABILITY OF GREATER THAN AN
INCH OF RAIN THIS WEEKEND THROUGH MONDAY AROUND 40-50 PERCENT
WITH AROUND 20 PERCENT CHANCE OF GREATER THAN 2 INCHES.
AVIATION /18Z WEDNESDAY THROUGH MONDAY/
VFR CONDITIONS EXPECTED THROUGH THE EVENING. RESTRICTIONS IN
STRATUS/FOG APPEAR MORE LIKELY THURSDAY MORNING WITH INCREASING
LOW LEVEL MOISTURE.
FEW TO SCT FAIR WEATHER CUMULUS HAVE DEVELOPED THIS AFTERNOON
WITH LIGHT SOUTHERLY TO SOUTHEASTERLY FLOW. AS THE SURFACE HIGH
SHIFTS OFFSHORE, CONTINUED SOUTHEASTERLY FLOW IS EXPECTED
OVERNIGHT BRINGING INCREASING MOISTURE. SKIES WILL CLEAR THIS
EVENING BEFORE GUIDANCE SUGGESTS ANOTHER ROUND OF MORNING
STRATUS AND POSSIBLE FOG DEVELOPING AFTER 08Z, MAINLY ALONG THE
COASTAL PLAIN AND SPREADING INLAND FAVORING THE CSRA AND EASTERN
MIDLANDS. TEMPOS HAVE BEEN ADDED FOR THE POTENTIAL FOR MVFR/IFR
CONDITIONS BETWEEN 09-13Z AT ALL SITES. SOME LIFR CONDITIONS
CANNOT BE RULED OUT, PARTICULARLY AT OUR FOG PRONE SITES WHERE
VISIBILITIES COULD DROP TO 1SM AT TIMES. LIGHT AND VARIABLE
WINDS AROUND 5 KNOTS, GENERALLY FROM THE SOUTHEAST, ARE EXPECTED
BY MIDMORNING AS RESTRICTIONS BEGIN TO LIFT.
EXTENDED AVIATION OUTLOOK...INCREASING CHANCES OF PRECIPITATION
THIS WEEKEND MAY LEAD TO ADDITIONAL RESTRICTIONS.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
DISCUSSION...96
AVIATION...ND
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