Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
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605 FXUS62 KCAE 070536 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 136 AM EDT Sun Jul 7 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 THIS 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 THIS 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 /06Z SUNDAY THROUGH THURSDAY/... Restrictions expected toward morning with low clouds and patchy fog. Deep moisture across the area today. Satellite and observations indicating scattered low clouds at 06z with mid and high level ceilings. Models are suggesting stratus will develop toward daybreak with relatively high confidence for MVFR conditions with areas of IFR ceiling/visibility after 09z with highest confidence at the AGS/DNL terminals. Low clouds will be slow to erode but by 15-18z expect VFR ceilings and light and variable winds favoring southeast-south. Scattered to numerous thunderstorms expected to develop in the afternoon as air mass will be moist and moderately unstable. CAM models show different solutions but think thunderstorms will develop in the SC Piedmont near the front and expand to the east/southeast during the late afternoon and early evening. Thunderstorms will be capable of producing heavy rain/reduced visibility at times. EXTENDED AVIATION OUTLOOK...Restrictions possible in diurnally driven showers and thunderstorms each day. Early morning low stratus possible. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$