Area Forecast Discussion
Issued by NWS Greer, SC
Issued by NWS Greer, SC
563 FXUS62 KGSP 091753 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 153 PM EDT Thu Oct 9 2025 .SYNOPSIS... Dry high pressure builds into the region through Friday bringing cooler temperatures. Low pressure will form off the Southeast coast Friday night and should track northward over the Outer Banks this weekend, bringing a chance of rain to parts of the western Piedmont. A warming trend develops early next week, with above normal temperatures returning by the middle of next week. && .NEAR TERM /THROUGH FRIDAY/... As of 140 PM EDT Thursday: Strong ~1035mb continental surface high currently centered over the Great Lakes region continues to drive in much cooler and drier air from the northeast. Dewpoints have plummeted into the low to mid 40s, especially as deeper mixing commences for this afternoon and evening. Some cloud cover is lingering in the southwest portions of the area as a shortwave trough gets its act together just west of the CWA. Wind gusts up to 20-25 mph will continue through the rest of the day as well with the continued low-level CAA. Afternoon highs will be ~5 degrees below normal today. Boundary layer will have a hard time fully decoupling overnight in an otherwise good radiational cooling setup, which will not allow overnight lows to reach their full potential. Overnight lows will run ~5 degrees below normal. The shortwave trough will maneuver over the Southeast tonight and Friday as the cold front from yesterday has become quasi-stationary over the Gulf and Southeast Coasts. Expect for weak surface cyclogenesis to commence as a coastal low develops along this boundary over the Southeast Coast by Friday. The pressure gradient between the surface high over the Northeast and the developing coastal low will help keep breezy conditions around through the end of the forecast period. Some mid- to upper-level clouds associated with the coastal low may move across the I-77 corridor by Friday afternoon as well. However, continued low-level CAA will keep temperatures at bay as afternoon highs on Friday remain ~5 degrees below normal. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... As of 1230 PM EDT Thursday...The situation over the weekend is complicated by the weak upper low drifting over the Southeast and interacting with the old cold frontal boundary. The models have been showing cyclogenesis off the Southeast coast Friday night into Saturday and that remains the case. The uncertainty/problem has always been how close to the coast the sfc low will track over the weekend as the system then starts to interact with a compact but strong upper low dropping southeastward across the Great Lakes. The trend on this model cycle is closer to the coast, with a westward shift of the western edge of the precip shield. Altho the operational runs of the models still look essentially dry, the ensembles have much more support for bringing some light rain into the area along/east of I-77 starting as early as Saturday morning, with the best chance Saturday night as the sfc low tracks across the Outer Banks. The area could use some rain, but don`t get your hopes up. Even if the I-77 corridor sees the light rain, amounts look like they would be a tenth of an inch or less, which would hardly make a dent. What the model trend will do is make Saturday a more cloudy and breezy day. In spite of the weakening of the dry wedge across the region, increased cloud cover will keep temps down around 5-10 deg below normal. Once the system lifts northward and past our region on Sunday, temps should rebound a bit, ending up only a few degrees below normal. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... As of 1240 PM EDT Thursday...the rest of the forecast looks fairly quiet. The compact upper low diving down from the Great Lakes will pass across the Mid-Atlantic region on Monday, close enough to do something if it wasn`t so moisture-starved. But, alas, there won`t even be enough moisture at low levels to result in any upslope activity on the TN border. From Monday night onward, a mean mid/upper ridge position to our west will keep a NW to WNW flow aloft and weak high pressure across the region. The GFS has at least one shot of low level moisture during the middle of the week that could support some upslope shower activity, but the chances are too remote to mention thus far. Thus, we have a dry medium range. Temps go thru a warming trend, with highs ending up about five degrees above normal for Tuesday and Wednesday, aided by some westerly downslope flow east of the mtns. Low temps will stay well above freezing across the higher terrain. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... At KCLT and elsewhere: VFR conditions will prevail at all terminals through the TAF period as any cloud cover continues to dissipate. Winds will be gusty out of the northeast through a good portion of the forecast period, especially during the daytime and becoming more sporadic during the evening and overnight hours. KAVL will keep a south-southeasterly component through this afternoon and switch to a north-northwesterly component overnight into Friday. Otherwise, mostly sunny skies continues into Friday outside of some mid- to uppper-level clouds approaching KCLT by the very end of the forecast period. Outlook: Drier conditions are expected to persist for the remainder of the week and into the weekend. Patchy morning fog/low stratus will be possible in the mountain valleys starting this weekend, otherwise VFR conditions are anticipated. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...PM NEAR TERM...CAC SHORT TERM...PM LONG TERM...PM AVIATION...CAC