Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
739 FXUS62 KCAE 101600 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 1200 PM EDT Thu Jul 10 2025 .SYNOPSIS... The threat for damaging winds and localized flash flooding will continue across the forecast area today due to the passage of an upper trough to our north. This trough is replaced by ridging this weekend, allowing temperatures to slowly rise with typical summertime showers and thunderstorms. The ridge breaks down early next week, leading to cooler temperatures and higher rain chances once again during the middle of next week. && .NEAR TERM /THROUGH TONIGHT/... Key Message(s): - Scattered showers and elevated thunderstorms expected overnight. - More widespread storms likely Thursday afternoon with some damaging winds and flash flooding possible. The slow moving trough will continue to shift eastward overnight tonight and throughout the rest of Thursday. The synoptic forcing is relatively weak with only minimal height falls but PWAT`s over 2.0" and some elevated instability will continue to drive some scattered showers-storms through early Thursday morning. A lull in the convection is then expected until the afternoon before another wave of diurnally driven pulse convection develops downstream of the trough axis, now over the TN Valley and southern Appalachians. Southwesterly flow will increase and therefore provide some faster storm motions this afternoon compared to Wednesday, but deep cloud layer shear is still minimal, only 10-15 knots. So the convective mode will still be pulse, but with some translational speed today. From an instability standpoint, abundant low level moisture will allow 1500-2000 j/kg ML CAPE to develop again this afternoon, but there is little dry air aloft, so DCAPE`s like Wednesday will be low. Hi-res guidance is consistent in developing a widespread field of convection by 20z, which realistically will be 18-19z. The eastern half of the forecast area, south of I-20 and along I-95, is favored from an initiation and instability perspective. So overall, another quantity over quality day is expected with at least a few strong-severe storms given the widespread coverage. The flash flooding threat flips around somewhat today compared to Wednesday with more progressive storm motions expected but also more sensitive basins after yesterday`s rainfall. So similar to Wednesday, as PWAT`s remain above 2.0", some widespread nuisance flooding is likely and a few isolated spots of flash flooding possible if we develop any training storms; HREF LPPM suggests a few areas of training, with a high end potential again of 3-5" like Wednesday. && .SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/... Key Message(s): - Little change in the weather each day, with seasonal temperatures and scattered afternoon and evening showers and thunderstorms. The upper trough lifts out of the region on Friday as ridging slowly builds into the region. This should result in a gradual decrease in rain chances each day, with a slow rise in daytime temperatures. PWATs remain high, particularly on Friday, so while no forcing will be present, scattered afternoon and evening showers and thunderstorms should still develop. Any robust thunderstorm has the potential to become strong, producing downburst winds and perhaps some small hail. Will also need to continue to monitor the flash flooding potential as thunderstorms should not move much. As is typical with pulse convection, storm position and motion will likely be dictated by the sea breeze and any mesoscale boundaries leftover from convection on the previous day. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... Key Message(s): - Above normal temperatures on Monday with heat indices in the 100 to 105 degree range. - Upper ridging breaks down resulting in near normal daytime temperatures and higher rain chances for the middle of next week. Latest guidance suggests that upper ridging will be strongest at the start of the extended, before breaking down during the middle of next week. Monday will likely be the hottest day of the next seven, with above normal daytime temperatures and heat indices in the 100 to 105 degree range. Rain chances should also be lowest on Monday before increasing during the middle of next week when we return to a more typical summertime pattern. && .AVIATION /16Z THURSDAY THROUGH MONDAY/... Periodic restrictions through the TAF period with stratus, followed by showers and thunderstorms this afternoon into this evening. Lingering showers and stratus likely for another hour or two with brief clearing from west to east. This afternoon, expect SCT-NUM SHRA/TSRA at all TAF sites. Restrictions are expected with the strongest storms due to likely heavy rainfall, particularly impacting VSBYS. Best chance for TSRA generally 19-01z with showers or storms in the vicinity an hour or two before and after this window. Winds with TSRA may be gusty up to around 30 kts. Outside of convective gusts, surface winds generally SLY at 10 kts or less. Debris cloudiness expected overnight with winds dropping to light and variable to calm. Expect additional CIG/VSBY restrictions toward daybreak Friday, particularly at locations which receive heavier rainfall today. EXTENDED AVIATION OUTLOOK...There is the possibility of diurnally driven showers and thunderstorms this week with the potential for periodic restrictions. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$