Area Forecast Discussion
Issued by NWS Greer, SC
Issued by NWS Greer, SC
568 FXUS62 KGSP 280551 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 151 AM EDT Thu Aug 28 2025 .SYNOPSIS... High pressure remains in control through much of the rest of the week. Cooler and drier weather continues through the rest of the week with some increase in moisture over the weekend that may result in scattered afternoon and evening showers and storms. && .NEAR TERM /THROUGH TONIGHT/... As of 1227 AM EDT Thursday: Satellite imagery shows a thickening veil of cirrus moving in from the WNW at this early hour, probably aided by some weak mid/upper forcing from a jet streak and short wave dropping down into the eastern trof. There remains a high-based stratocu cloud deck underneath across the mtns and foothills that is being obscured. The increasing clouds should keep the low temps a few degrees warmer than last night, but still on the order of five degrees below normal. Fog looks unlikely. The aforementioned jet streak and short wave should move overhead today while the center of sfc high pressure gets pushed off to the east. Fair weather will continue, but with more clouds that are variable through the day. The clouds will act to keep high temps close to what we`ve had the past few days in spite of modification of the air mass. Yet another short wave will drop down and sharpen the upper trof tonight, but the forcing and moisture are expected to move past well to our north. Instead, we will be left with a weak remnant sfc high between this northern unsettledness and a weak quasi-stationary front along the Gulf Coast. The result will be another night of fair weather, but with temps and humidity a bit higher, though still below normal. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... As of 129 AM EDT Thursday: Broad cyclonic flow aloft remains in place heading into the weekend as a closed mid/upper-level low churns near the Ontario/Quebec border, favoring the Quebec side. Deep layer west-northwesterly flow Friday will induce dry air entrainment and keep the sensible weather quiet. Weak downslope component and clearer skies will help temperatures uptick a few degrees on Friday compared to earlier in the week as afternoon highs climb into the low to mid 80s. Dry air will continue to advect across the area Friday night as a surface high moves toward and over the Great Lakes region. However, a stalled frontal boundary over the Deep South and Gulf Coast will gradually support better upglide and fetch a weak moisture transport into the area over the weekend. Model guidance continue to trend drier for Saturday as any real moisture advection will have to overcome a dry antecedent air mass. Eventually, isentropic lift should secure the win as the moisture will gradually be able to overcome the antecedent conditions and provide enough lift for showers to generate sometime during the second half of the upcoming weekend. Model guidance differ on timing and overall coverage, but continue to show some QPF response form during the peak diurnal timeframe Saturday into Saturday night. This has allowed for slight chance to chance PoPs across portions of the region, with the best chances being in the southwestern zones where the better isentropic lift and moisture advection are present. Temperatures will decrease a degree or two on Saturday compared to Friday thanks to an increase in cloud cover and the better potential for any kind of shower activity. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 145 AM EDT Thursday: Broad upper troughiness lingers through a good chunk of the period as the pattern continues to be reinforced by a series of mid-level lows and a deep digging jet streak. The synoptic pattern at the surface includes a wedge-like configuration and the quasi-stationary front in the vicinity of the Gulf Coast region. The two will battle it our during the extended period and provide the better chance for precip Monday before the aforementioned boundary over the Gulf Coast favors a southerly drift. This will help to induce drier air across the CWFA through the extended. Model guidance are keying in on a stronger cold front just beyond the forecast period as a closed upper low digs in across the north-central CONUS, but the area looks to remain relatively quiet ahead of that feature. Temperatures will be 5-10 degrees below normal on Monday with better cloud cover and higher PoPs. However, a gradual warming trend takes place thereafter as drier air filters in and less cloud cover overall. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... At KCLT and elsewhere: VFR at all terminals through the period. There`s always a small chance of valley fog/stratus at KAVL at daybreak at this time of year, but with the extensive cloud cover that appears unlikely enough to omit. Wind should stay light/variable thru most of the morning. Toward midday, the cloud cover should thin out a bit and the wind should come around to the S or SW and light as the high pressure center moves off to the east. Winds should go back to light/variable with sunset. Broken/overcast Mid/high clouds will remain. Outlook: Dry conditions remain through Friday. Showers and thunderstorms, and associated restrictions, may return for the weekend into Monday. Fog and/or low stratus may develop each night, mainly in the mountain valleys. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...CAC NEAR TERM...PM SHORT TERM...CAC LONG TERM...CAC AVIATION...PM