Area Forecast Discussion
Issued by NWS Greer, SC
Issued by NWS Greer, SC
194 FXUS62 KGSP 232320 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 720 PM EDT Sun Aug 23 2026 .WHAT HAS CHANGED... The aviation forecast updated for the 00Z TAF issuance. && .KEY MESSAGES... 1. Dry weather with comfortable humidity levels through Tuesday. Daily shower and thunderstorm chances return Wednesday and continue through the rest of the week. && .DISCUSSION... Key message 1: Dry weather with comfortable humidity levels through Tuesday. Daily shower and thunderstorm chances return Wednesday and continue through the rest of the week. Amplified upper pattern will persist over the CONUS through the first half of this week, with deep anticyclone remaining centered near New Mexico and closed low over the eastern periphery of the Great Lakes. At the surface we will be on the cool side of a front stalled in the I-20 corridor. Monday the pattern will support northwest winds, advecting dry continental air into the region. Profiles are unfavorable for deep convection with only shallow cumulus expected. Cold advection will be offset by insolation and downslope flow, such that daytime temperatures run near normal. Afternoon mixing should maintain low dewpoints in the lower 60s or even upper 50s. Overnight lows will be a few degrees below normal on account of the lower dewpoints and good radiational cooling conditions. The upper pattern becomes less amplified over the area by Tuesday as the closed low drifts further east and its influence over the southern Appalachians diminishes. Broadly cyclonic flow will remain over the eastern half of the CONUS. Most guidance shows weak northerly winds at the surface, though winds aloft begin to favor southwest in response to more influence of the Plains ridge, and some moisture return aloft. In turn dewpoints rebound a bit though still mainly in the lower to mid 60s, while temperatures will remain near normal. This looks unlikely to have much impact on convective chances; more models/ensemble members depict our whole area remaining dry through Tuesday compared to yesterday`s runs. Weak sfc high in the Midwest is expected to fill and drift east by Wednesday; heights fall slightly aloft in the mid-MS Valley in advance of the next shortwave rotating into the broad trough. These changes effectively reactivate the front and bring it northward into our area; dewpoints and temps rise and diurnal showers/storms again appear possible. Interaction between the shortwave and the front suggests a continuing chance of showers/storms overnight into Thursday (when precip chances are greatest between now and next weekend). Though there are indications the passage of that shortwave may push the front back to our south and east at least briefly, it appears unlikely airmass change will occur. Hence we will remain seasonably hot and humid through the end of the period with a chance for primarily diurnal convection each day. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... At KCLT and elsewhere: Any lingering stratocu dissipates early this evening leaving cirrus for the overnight. Expect another round of mountain valley fog overnight with restrictions reaching KAVL. Some cirrus lingers through the day with some high based VFR stratocu for the afternoon. Winds become light N to NE this evening and continue into the morning. Winds pick up from the W to NW for the afternoon. NW with low end gusts at KAVL. Outlook: No significant chance of convection until Wednesday with an even better chance Thursday into Friday. Mountain valley fog and low stratus is possible each morning. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ JCW/RWH