


Area Forecast Discussion
Issued by NWS Greer, SC
Issued by NWS Greer, SC
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-- Discussion containing changed information from previous version are highlighted. --646 FXUS62 KGSP 290512 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 112 AM EDT Sun Jun 29 2025 .SYNOPSIS... A typical summer pattern continues into early next week with seasonable temperatures and daily chances for afternoon and early evening thunderstorms. A cold front approaches the area on Tuesday and drier weather may return for the holiday weekend. && .NEAR TERM /THROUGH TODAY/...-- Changed Discussion --As of 1215 AM EDT Sunday: A few decaying storms are still trying to hang on as their outflow boundaries shoot southward. These stubborn storms in the southern zones have been painstakingly slow to diminish but should calm down in the next hour. Satellite shows a broad area over the Upstate of convective cloud debris scattering slowly. There is also a few areas in the mountain valleys lighting up with fog already. This will continue to increase through the night and disappear after daybreak. Otherwise, while guidance is showing the air mass won`t be as unstable Sunday, it will still be moderately unstable. PW values remain high with even less mid level dry air leading to lower DCAPE and sfc delta theta-e values. However, forcing will be enough for more diurnal convection favoring the mountains and foothills with scattered coverage elsewhere. Severe chance is lower but heavy rain chance higher given the previously mentioned conditions. Training or anchoring of cells will be possible once again. Highs will be near normal across the mountains and a few degrees above normal elsewhere.-- End Changed Discussion --&& .SHORT TERM /TONIGHT THROUGH TUESDAY/... As of 1221 PM Saturday: The forecast continues tomorrow night with broad Bermuda ridge extending across the Atlantic and into the southeast coast. Farther upstream, a northern stream trough will be swinging across the Canadian Prairies and Northern Plains. The trough is progged to slide across the Midwest on Monday and across the Great Lakes into New England on Tuesday. Weak deep-layer southwest flow will keep a moist sub-tropical airmass entrenched across the area with PWATs of 1.75-2". A persistence forecast seems likely on Monday with scattered to numerous diurnally driven thunderstorms with the greatest rain chances across the mountains. Outflow boundaries pushing out of the mountains may initiate new scattered convection mainly along and north of I-85 with generally isolated to widely scattered coverage farther south/east. The forecast turns wetter on Tuesday as the previously mentioned trough passes north of the area and drags a cold front within the trough axis towards the area. Deep moisture pooling ahead of the boundary along with a slight uptick in flow/weak forcing will prove sufficient to instigate numerous to widespread afternoon/early evening storms across much of the area. Storms may loosely organize into clusters/linear segments along composite cold pools. As with any summer convection, a few strong to isolated severe storms cannot be ruled out with the main threat being wet microbursts. The environment won`t be overly conducive to damaging winds with poor lapse rates, DCAPE, surface delta ThetaE and vertical totals - thus any severe threat should remain fairly isolated. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... As of 1232 PM Saturday: The latest suite of global model guidance is in fairly good agreement that the frontal boundary will slide into the area on Wednesday with another day of fairly high coverage of diurnal thunderstorms. By Thursday, the boundary begins to push south and east of the area with much lower ThetaE air arriving in its wake. This would shunt the greatest rain chances south of the area with a return to a mostly dry forecast. Depending on how far south the boundary makes it, the forecast may remain dry through the 4th of July holiday weekend. Of course a few isolated showers/storms can never be ruled out over the mountains even in a post-frontal airmass. Should the boundary stall over or near the area, however, the forecast would stay active through the holiday weekend. Current model trends support the drier forecast, so will keep rain chances in line with the national model blend with only isolated chances being advertised. && .AVIATION /05Z SUNDAY THROUGH THURSDAY/...-- Changed Discussion --At KCLT and elsewhere: VFR conditions prevail through the TAF period at most sites. Similar to the last few days, calm to light VRB winds overnight and picking up again slowly in the late morning. High pressure off to the west of the area allows for more southerly winds Sunday afternoon, but light. KAVL remains mostly NW. Another round of BR/FG possible at KAVL and KHKY in the wee hours this morning. Confidence isn`t high enough to prevail as the area did not receive much rainfall earlier in the day. So will keep a TEMPO going from 09z-12z. Sunday afternoon rings in another chance for scattered showers and TSRA, possible anywhere especially in the mountains. PROB30s again at all terminals for the TSRA. Once showers and thunderstorms clear up, another calm night to round out this TAF forecast. Outlook: Daily chances for afternoon and evening showers and thunderstorms into next week. Fog and/or low stratus possible each morning in the usual mountain valleys as well as near lakes and rivers.-- End Changed Discussion --&& .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...CP NEAR TERM...CP/RWH SHORT TERM...TW LONG TERM...TW AVIATION...CP