Area Forecast Discussion
Issued by NWS Greer, SC
Issued by NWS Greer, SC
141 FXUS62 KGSP 132304 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 704 PM EDT Sun Sep 13 2026 .WHAT HAS CHANGED... The forecast has trended a bit drier for the first half of the week. The aviation discussion has been updated for the 00z TAFs. && .KEY MESSAGES... 1. Our area should remain mostly dry through the first half of the week. Diurnal shower and thunderstorm chances increase for the latter half of the week with temperatures remaining above normal for mid-September. && .DISCUSSION... Key message 1: Our area should remain mostly dry through the first half of the week. Diurnal shower and thunderstorm chances increase for the latter half of the week with temperatures remaining above normal for mid-September. In the wake of a weak frontal passage, we could see a few showers and maybe an isolated thunderstorm or two this afternoon/evening. Otherwise, the weather should be mostly quiet with temperatures roughly 3 to 6 degrees above normal. A stout upper shortwave is expected to pass to our north on Monday, helping to push a back door cold front southward across our area. The model guidance continues to show little in the way of response wrt the fropa. This makes sense given the weak cap and minimal CAPE across the region Monday afternoon/evening as it moves through. On Tuesday, broad upper ridging spreads over the Southeast from the west and persists thru mid-week. The upper ridge will help support sfc high pressure that migrates eastward from the lower Great Lakes to New England from late Monday through Tuesday. On Wednesday, the sfc high gets pushed off the New England Coast by robust low pressure tracking across eastern Canada. Brief, weak cold air damming tries to develop on Tuesday, however a lack of moisture in the light ELY low-level flow will likely produce little in the way of precipitation. In addition, the expected lack of persistent cloud cover thru the day should allow high temperatures to top-out near, if not a few degrees above normal. If better cloud cover lingers for longer, fcst tempera- tures could be too warm. For the second half of the week, a frontal boundary stalls just to our north while a weak surface low tries to develop somewhere off the coast of south Florida. At present, the deeper moisture associated with the frontal bndy appears to remain mostly over the mtns each day, suggesting a chance of diurnal showers and storms each day Thursday thru Saturday with temperatures remaining 1 to 2 categories above normal for mid-September. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... At KCLT and elsewhere: VFR conditions will prevail at most terminals through the forecast period. The arrival of a drier airmass will continue to preclude the development of afternoon showers/storms along with a dearth of low stratus and fog owing to a much drier boundary layer. The one exception will be the potential for mountain valley fog/stratus and associated restrictions at KAVL. Any valley fog should mix out shortly after sunrise. A stray shower cannot be ruled out along a backdoor cold front tomorrow afternoon, but coverage should remain limited enough to preclude mention in any TAF. Otherwise, light to calm winds overnight with light north/northeast winds during the day Monday. A few low-end gusts will be possible at KAVL during the afternoon and early evening hours. Outlook: Mostly dry conditions are expected to persist through the middle of the week. Shower chances and their associated restrictions increase later in the week. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ JPT/TW