707 FXUS62 KGSP 061751 AFDGSPArea Forecast Discussion National Weather Service Greenville-Spartanburg SC 151 PM EDT Sat Sep 6 2025
.SYNOPSIS... A moist cold front will bring scattered to numerous showers and thunderstorms to our area this afternoon and evening. A few strong to severe storms are possible. Cooler and drier weather returns on Sunday and lingers through most of next week.
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.NEAR TERM /THROUGH SUNDAY/... As of 150 PM EDT Saturday: A broad area of showers with embedded thunderstorms is slowly moving into the mountains at this time. This convection will steadily spread across the area into the early evening, moving east by midnight. Mesoanalysis shows sbCAPE greater than 1500 J/kg for most of the area with effective bulk shear in the 30 kt range. Low level lapse rates are increasing and DCAPE is generally 700 J/kg or greater along and south of the I-85 corridor. Therefore, expect a better chance of semi-organized severe storms in that area. That said, an isolated strong to severe storm is possible north of I-85, especially as the storms initially move in. Damaging winds are the main threat, but some marginally large hail is also possible.
Winds shift to the N to NE overnight behind the departing cold front as high pressure builds in from the north. Low level moisture also increases on this flow leading to cloudy skies. Fog is also possible, especially in the normally more foggy areas. Lows will be near normal.
Low level moisture lingers across the area in the northeasterly flow even as high pressure continues to build in. This will keep low clouds across the area through the morning. Isolated to perhaps scattered showers and a few storms will be possible in this moist flow. Highs will show close to a 10 degree NE to SW gradient across the area also due to the high pressure building in. Highs will range from 5 to 10 degrees below normal with the warmest readings along the Upper Savannah River Valley into the normally warmer NC mountain valleys west of the French Broad.
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.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... As of 1:35 PM EDT Saturday: The short-term fcst picks up at 00z on Monday with long-wave upper trofing centered just to our north while broad upper ridging covers the western CONUS. Over the next couple of days, the upper trof will lift northward with heights rebounding over our area. At the sfc, robust high pressure will be spreading over the Southeast as the period begins late Sunday bringing cooler and drier air for the rest of the period with no significant precip chances for our fcst area. Temperatures are expected to remain 5 to 10 degrees below climatology thru the period.
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.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... As of 1:15 PM EDT Saturday: The extended fcst picks up at 00z on Wednesday with broad upper trofing having retreated northward as heights rebound over our area. Over the next few days, the large- scale pattern will amplify again as upper trofing digs down over New England and stout upper ridging persists to our west over the central CONUS. At the sfc, broad high pressure will be centered well to our NE over the Nova Scotia area but still covering most of the eastern CONUS. On Wednesday, the high will slide further NE while a weak sfc low tries to develop within the baroclinic zone just off the SE Coast. Most of the current long-range guidance has this weak low move up the Eastern Seaboard on Wednesday and Thursday, while its associated deeper moisture remains just east of our fcst area. Another robust high is then expected to migrate southward from Canada by late week and spread another round of drier air back over the Southeast. Overall, the sensible fcst remains largely unchanged. We can expect cool and mostly dry conditions thru the period. Temperatures are expected to warm on Wednesday and Thursday but still remain a few degrees below climatology. They will cool again by the end of period as the next round of high pressure spreads over the area.
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.AVIATION /18Z SATURDAY THROUGH THURSDAY/... At KCLT and elsewhere: A broad area of showers with embedded thunderstorms will move into the area ahead of a cold front this afternoon and cross the area into early evening. The period of convection could be somewhat prolonged, with multiple rounds of storms, even if direct impacts at the airfields will be relatively brief associated with individual cells. Therefore, have kept the PROB30 instead of a TEMPO for all sites to show the broader timing potential. SW winds, NW at KAVl, may have some low end gusts ahead of the front. Winds turn N to NE behind the front late this evening and overnight. MVFR stratocu develops overnight in the developing moist northeasterly flow. IFR is likely at KAVL and possible at KHKY. Any vsby restrictions should end by 14Z but MVFR cigs will linger until at least 16Z and could go longer. Some showers are also possible in the moist NE flow which could prompt additional restrictions. N to NE winds continue through the day.
Outlook: Dry high pressure is expected into the middle of next week. Fog and/or low stratus is possible each morning, especially in the favored mountain valleys.
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.GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None.
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SYNOPSIS...JPT NEAR TERM...RWH SHORT TERM...JPT LONG TERM...JPT AVIATION...RWH
NWS GSP Office Area Forecast Discussion