Area Forecast Discussion
Issued by NWS Greer, SC
Issued by NWS Greer, SC
586 FXUS62 KGSP 082349 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 749 PM EDT Fri Aug 8 2025 .SYNOPSIS... Cold air damming lingers into the weekend with temperatures remaining below average. The pattern begins to change late weekend into next week as the cold air damming wedge breaks down and a more typical late pattern resumes with daily afternoon/evening thunderstorms. && .NEAR TERM /THROUGH SATURDAY/... As of 745 PM EDT Friday: CAD wedge persists in the CWA. Deck of stratocu has scattered a decent bit across the area, but will persist through the evening and into the overnight. Most of the shower activity has diminished outside of Smokies. Otherwise, the forecast remains on track. Low pressure on the periphery of the wedge, now just off the Outer Banks, will continue to drift NE. The parent high looks to weaken thru Saturday as upper diffluence develops over it and via sfc modification. However, RH in the 925-850mb layer remains high tonight on most model progs; weak easterly flow continues, so low altitude clouds appear likely to develop again overnight, although probably not over as deep a layer as we saw Thursday night. Hence they stand a better chance of dissolving during the morning. With that, and with the weaker wedge, temperatures should trend warmer tomorrow with highs mostly in the lower to mid 80s for the Piedmont, and lower 80s for mountain valleys. With weak forcing and lapse rates no better than today, PoPs mostly remain below slight-chance except for a few spots in the far western mountains and in the southern SC/GA Lakelands. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... As of 1156 AM Friday: A pattern change will be on the horizon by the later half of the weekend as a mean longwave trough settles across the Great Plains with a lead shortwave lifting across the Great Lakes region. Surface high pressure meandering just off the east coast to the Mid-Atlantic states finally gets kicked far enough offshore to allow for a breakdown of the CAD wedge with winds shifting to out of the southeast. This will also in turn allow for deeper moisture to surge back into the area with PWATs rising to 1.5- 2" on Sunday. Associated diurnally driven showers and thunderstorms are expected to once again grace the area, especially along and south of I-85 in closer proximity to the best moisture. This regime will continue into Monday with scattered to numerous afternoon/early evening showers and thunderstorms possible across the area. As with any summer storms, isolated flooding from locally heavy rain along with strong winds from wet microbursts cannot be ruled out. But the overall environment is not conducive to an organized severe weather threat owing to poor thermodynamic profiles. Temperatures will remain mild and well below normal with copious cloud cover keeping afternoon highs in the low 80s. && .LONG TERM /TUESDAY THROUGH FRIDAY/... As of 1212 PM Friday: By Tuesday into mid/late next week, guidance is in good agreement that broad subtropical ridging over the Atlantic retrogrades into the southeast states with rising heights across much of the region. Farther north, a belt of northern stream westerlies will be draped across the northern CONUS with periodic shortwaves sliding across the Ohio Valley on the northern flank of the ridge. Temperatures will finally return to seasonable averages by Wednesday into late week with highs slowly creeping back into the mid 80s to low 90s. The broad and flat nature of the ridge shouldn`t completely suppress afternoon diurnal convection with at least scattered to numerous thunderstorms possible each day. Any hazards will remain isolated and confined to gusty winds from wet microbursts and locally heavy rainfall. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... At KCLT and elsewhere: SCT/BKN stratocu deck still in place across all terminals. Most of the precip has diminished and should remain that way through the overnight period. Cigs are generally VFR, but there are a few patches of MVFR cigs. Guidance once again wants to develop MVFR stratocu overnight, with some potential for IFR. Thinking there could be some fog that develops as well, mainly at KAVL and KHKY. Slow to scatter out the cloud deck after daybreak Saturday, but expecting VFR to return by mid-morning to early afternoon with stratocu sticking around through the end of the forecast period. Can`t rule out a rogue shower either, but confidence is too low for a TAF mention at this time. Northeasterly winds through the period, while KAVL maintains a southeasterly wind. Can`t rule out low-end gusts during peak heating on Saturday. Outlook: Daily diurnal showers and thunderstorms with associated restrictions return across the area from Sunday through Tuesday. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...TW NEAR TERM...CAC/Wimberley SHORT TERM...TW LONG TERM...TW AVIATION...CAC