Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
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093 FXUS62 KCAE 070302 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 1102 PM EDT Sat Jul 6 2024 .SYNOPSIS... Moisture increases, with scatter to numerous showers and thunderstorms expected through the weekend. Above normal temperatures are expected again, with Heat Index values above 100 each day through next week. Atmospheric moisture remains high through the long term supporting a chance of showers and thunderstorms each day. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... Widespread showers and thunderstorms are ongoing across the region, currently impacting the CSRA most significantly. Flash flooding is a definite threat with this activity as hourly rainfall rates per obs and radar have exceeded 3" per hour in the heaviest rain today. So will continue to watch this as PWs (per SPC Mesoanalysis) are exceeding 2.5" in this part of the forecast area. Storm motion is slow and with southwesterly flow aloft and plenty of converging boundaries, storms have been training this afternoon and evening. Do expect this activity to gradually wind down into a more stratiform precip by the middle of the night but it isn`t out of the question that showers hang around all night in isolated places given copious moisture. Temps should bottom out in the mid 70s tonight. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... Key message(s) - Not quite as hot with an increase in convective activity. Surface boundary stalled across the area will be the primary focusing mechanism for afternoon shower and thunderstorm develop once again on Sunday. Upper trough sets up across the middle of the U.S., with the southeastern States still on the western edge of the Atlantic Ridge aloft. Southwesterly winds aloft begin bringing more Gulf moisture into the area. By Monday the surface boundary will dissipate, and the main focus will be from left over convective boundaries, along with possible sea-breeze activity. Temperatures will cool slightly with the expected increase in cloud cover through the period, but will still be from around 90 to the middle 90s. Heat index around 100 both days. && .LONG TERM /TUESDAY THROUGH SATURDAY/... Key Message(s) - Continued with a more typical summertime weather pattern. Pattern will be somewhat stagnant aloft through the period. Upper trough remains across the middle of the country, with our area on the western portions of western Atlantic ridge. This general pattern will keep upper winds more out of the southwest, bringing Gulf moisture towards the region, while at the surface winds will be more out of the south to southeast allowing Atlantic moisture to move inland. Triggers for any afternoon convection will be inland moving sea-breeze and associated outflows moving in from the east, along with potential for lee- side trough over the west. There should be more cloud cover move across the region each day, so afternoon highs are expected to stay away from the century mark, with readings mainly in the lower to middle 90s. However with all the moisture in low- levels, heat index values will be able to rise back above 100 degrees through much of the period. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... VFR conditions through much of the TAF forecast period with restrictions possible in early morning fog/stratus possible and again in afternoon and evening convection. Showers and thunderstorms have generally dissipated with some rain lingering across the terminals for the next couple hours. Will handle the showers with a TEMPO for the next hour or two when all cells should have dissipated. Next concern will be for stratus and fog development as the moisture becomes trapped under the inversion. Cigs restrictions are more likely and have remained with MVFR cigs however there is potential for IFR cigs. Much will depend on the rainfall and ending time of the convection so will continue to monitor. Restrictions will mix out by 14z and with heating expect another day of convection across the terminals. Have included VCSH at all terminals from 18z through the end of the period and will adjust as confidence in timing and coverage increase. EXTENDED AVIATION OUTLOOK...Restrictions possible in diurnally driven showers and thunderstorms each day. Sunday is expected to have the highest coverage in the extended period. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$