Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
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933 FXUS62 KCAE 080908 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 508 AM EDT Wed May 8 2024 .SYNOPSIS... Potential for strong to severe storms Wednesday through Thursday night ahead of an approaching cold front. Drier conditions return for the weekend. Expect generally above average temperatures through the latter half of the week before transitioning to near or slightly below average during the weekend. && .NEAR TERM /THROUGH TONIGHT/... The axis of an upper level ridge will move over the forecast area today with a weak shortwave moving over top of the ridge in the late afternoon and early evening. SW, low-level flow will advect moisture into the Southeast, pooling near a convergence boundary along the NC/SC border. Broad ridging should largely suppress convection over the forecast area. However convection may be able to develop to the north, further away from the ridge, as the shortwave moves through in the afternoon. CAMs are in decent agreement in the location of convective initiation being in the NC/SC Piedmont, growing upscale as it moves SE through the late afternoon and evening. Moderate instability, moderate deep layer shear, and low wet- bulb zero heights will be supportive of large hail and damaging winds in the Carolinas. As the air mass destabilizes in the afternoon median mixed layer CAPE values from the SREF are around 2000 J/kg. 0-6km shear values of 25 to 30 kts will be supportive of organized convection. The HRRR has been consistent showing initial convection beginning in central NC with cold pool driven convection pushing into the northern Midlands during the afternoon. DCAPE values of 1000 to 1200 J/kg and WBZ heights of around 10000 ft are favorable for swaths of damaging winds and large hail if thunderstorms develop. The tornado threat is lower given the lack of helicity and weaker 0-1km shear, but can`t be ruled out. Tonight, there could be additional rounds of showers and thunderstorms as warm, moist advection strengthens over the region. Divergence aloft also becomes more favorable as a jet moves to our north tonight. Confidence in severe weather during the overnight period is low. The warm advection leads to a near- surface inversion which could prevent winds from mixing to the surface despite the expected larger number of storms. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... Potential for multiple rounds of strong to severe storms as MCS`s move through the southeastern States. SPC continues to show the entire forecast area in a Slight Risk Thursday and Thursday night, with the main threat being damaging winds. However large hail and even an isolated tornado can not be completely ruled out. Still plenty of uncertainty through the period, due to a warm nose aloft to start off the day Thursday. Guidance does show the potential for a decaying MCS to be moving into the northern Midlands during the morning to start off the day Thursday, which would then lay down a surface outflow boundary across the forecast area. This then becomes the primary focus for additional MCS development across the Central Midlands and CSRA during the afternoon. , and then into the overnight hours on Thursday night. Convective models still vary in regards to overall coverage with each potential system, along with even the placement and movement of them. This has much to do with the strength of the warm nose, and if/when if finally weakens enough to aid in convection. So have a low confidence in overall coverage and movement, but a moderate to high confidence that any storms that develop with have the potential to become severe as they track across the cwa. Temperatures remaining above normal, but do begin to cool slightly from the hot readings of the past few days. && .LONG TERM /FRIDAY THROUGH TUESDAY/... Cold front that has been driving a good portion of the convection west of the region will finally begin to push into and through the cwa on Friday. Lingering showers and storms will remain possible early in the day, with the CSRA still having a potential for strong to severe storms again Friday afternoon with a system moving out of central GA through the morning. By late Friday afternoon, drier air finally begins to push into the cwa, and should see a drying trend into Friday night. Cooler and drier weather then should dominate into the weekend behind the front. Rain chances will then begin to increase again Monday and Tuesday as moisture returns. && .AVIATION /09Z WEDNESDAY THROUGH SUNDAY/... Early this morning, a 25 knot low level jet should help keep the boundary layer mixed and surface winds in the 3 to 5 knot range hindering fog development. SW winds should pick up to around 10 knots by 15Z with gusts up to 20 kts through the afternoon. Strong thunderstorms may develop this afternoon but are more likely than not to remain north of the terminals. Tonight, thunderstorm coverage may actually increase as moisture increases. There could be periods of storms and reduced visibility at the TAF sites overnight, but confidence is too low to include at this time. SSW Winds should stay up overnight around 5 kts. EXTENDED AVIATION OUTLOOK...Active weather continues Thursday with severe thunderstorms possible. Then expect another day of convection and associated restrictions on Friday. Drier weather likely for this weekend.&& .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$