117
FXUS62 KCAE 040701
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
301 AM EDT MON MAY 4 2026
WHAT HAS CHANGED
AVIATION DISCUSSION UPDATED FOR 00Z TAFS.
KEY MESSAGES
- 1. PERIODS OF MODERATE TO HEAVY RAINFALL ARE EXPECTED DURING
THE MID WEEK WITH THE POTENTIAL SEVERE WEATHER.
DISCUSSION
KEY MESSAGE 1: PERIODS OF MODERATE TO HEAVY RAINFALL ARE
EXPECTED DURING THE MID WEEK WITH THE POTENTIAL SEVERE WEATHER.
SUMMARY: THE RAINFALL FORECAST REMAINS ON TRACK FOR MID-WEEK AS AN
UPPER LEVEL TROUGH DIGS INTO THE CENTRAL US, PHASES WITH SOUTHERN
STREAM ENERGY, AND SHIFTS EASTWARD. THE ASSOCIATED SURFACE COLD
FRONT WILL WORK INTO THE SOUTHEAST ON THURSDAY. MODELS CONTINUE TO
SHOW AGREEMENT IN OVERALL SYNOPTIC PATTERN DESPITE DIFFERENCES IN
THE TIMING OF THE FRONT AND OTHER DETAILS. THIS INCREASES CONFIDENCE
IN PERIODS OF MODERATE TO HEAVY RAINFALL BUT LEAVES THE THREAT OF
SEVERE WEATHER UNCERTAIN.
RAINFALL: ROBUST MOISTURE TRANSPORT IS EXPECTED AHEAD OF THIS FRONT
WITH PWAT VALUES REACHING THE NAEFS 99TH PERCENTILE BY THURSDAY
MORNING AND IVT ABOVE THE CLIMATOLOGICAL MAXIMUM. AS SYNOPTIC SCALE
LIFT MOVES OVER THE REGION LATE WEDNESDAY INTO EARLY THURSDAY,
SCATTERED SHOWERS AND STORMS SHOULD DEVELOP. COVERAGE WILL LIKELY
INCREASE THURSDAY MORNING AS MOISTURE TRANSPORT AND SURFACE
CONVERGENCE AHEAD OF THE FRONT INCREASES. THIS ACTIVITY COULD BRING
PERIODS OF MODERATE TO HEAVY RAIN AS FORECAST SOUNDINGS THURSDAY
MORNING DEPICT DEEP MOISTURE, A LONG/SKINNY ELEVATED CAPE PROFILE,
AND A 30-40 KT LLJ. WITH THE ANTECEDENT DRY CONDITIONS, THE OVERALL
FLASH FLOODING RISK IS EXPECTED TO BE ON THE LOW SIDE. THE FRONT IS
EXPECTED TO CLEAR LATE THURSDAY, BRINGING AN END TO RAIN CHANCES
FROM WEST TO EAST. GUSTY WINDS WILL ALSO BE POSSIBLE THURSDAY AND A
LAKE WIND ADVISORY MAY BE NEEDED.
SEVERE THREAT: THE THREAT OF SEVERE WEATHER WILL BE LARGELY
DEPENDENT ON THE TIMING OF THE FRONT. SOME OF THE TIMING DIFFERENCES
LIKELY STEMS FROM THE PROGRESSION OF THE UPPER TROUGH AND ITS
INTERACTION WITH A CUT-OFF LOW TO THE WEST. THERE IS ALSO SOME
UNCERTAINTY IN THE DEGREE OF DESTABILIZATION THROUGH THE DAY WITH
WIDESPREAD RAIN AND CLOUD COVER ANTICIPATED. THAT SAID, ECMWF EFI
VALUES FOR CAPE-SHEAR COMBO STILL RANGE FROM 0.6 TO 0.8 INDICATING
SOME POTENTIAL FOR DEEP SHEAR TO LINE UP WITH MODERATE
INSTABILITY.
AVIATION /06Z MONDAY THROUGH FRIDAY/
VFR CONDITIONS WILL PREVAIL THROUGH 06Z TUESDAY.
CLEAR SKIES AND LIGHT/CALM WINDS WILL PERSIST THROUGH THE
OVERNIGHT HOURS. AN OVERALL DRY AIRMASS SHOULD LIMIT FOG
POTENTIAL, BUT SOME RIVER VALLEY FOG CANNOT BE COMPLETELY RULED
OUT AT AGS/OGB.
WINDS ALONG THE BACK SIDE OF ATLANTIC HIGH PRESSURE WILL
INCREASE FROM THE SOUTHWEST TO 5-10 KT DURING THE LATE MORNING
AND AFTERNOON HOURS TODAY. WHILE THEY SHOULD DIMINISH WITH THE
LOSS OF DAYTIME HEATING THIS EVENING, THEY MAY NOT FULLY
DECOUPLE. THIN CIRRUS SHOULD BEGIN SPREADING OVER THE AREA THIS
AFTERNOON, POTENTIALLY INCREASING IN THICKNESS/COVERAGE TOWARD
THE END OF THE FORECAST PERIOD, BUT WILL HAVE NO IMPACT TO
AVIATION INTERESTS.
EXTENDED AVIATION OUTLOOK...DRIER CONDITIONS ARE EXPECTED
THROUGH TUESDAY, THEN A MIDWEEK SYSTEM BRINGS A CHANCE FOR
RESTRICTIONS ONCE AGAIN.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
DISCUSSION...CJR
AVIATION...JAQ
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