Area Forecast Discussion
Issued by NWS Greer, SC
Issued by NWS Greer, SC
309 FXUS62 KGSP 120547 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 147 AM EDT Sun Oct 12 2025 .SYNOPSIS... A coastal low will slowly drift north along the East Coast through early next week. This system may bring rain to the North Carolina Piedmont and eastern Upstate tonight this evening as it passes by to our east. The low will then drift offshore by midweek, as dry high pressure builds in from the west and brings above normal temperatures to the region. && .NEAR TERM /THROUGH TONIGHT/... As of 130 am EDT Sunday: A cyclone off the South Carolina coast is forecast to reach its nadir this morning, before beginning a steady weakening phase as it drifts slowly northeast through the period. The leading edge of a precip band associated with this feature has moved into the extreme southeast corner of our CWA, but is struggling to make much additional westward progress as it is encountering a region of rather dry mid-level air. As this layer slowly moistens, precip is forecast to make some additional westward progress through the morning, with PoPs peaking around 12Z before steadily diminishing...with likely-to-categorical probabilities confined to locations roughly east of a Union,SC=>Charlotte=>Salisbury line, tapering toward the west such that chances are <20% across roughly the western half of the CWA. Forecast precip amounts of 0.1-0.25" are coincident with the likely/categorical PoPs, although 0.5" or more is possible across portions of Union County, NC. Max temps are again forecast to be 5 or more degrees below normal under thicker cloud cover across the eastern third of the area, while highs are expected to be a category or so above climo across the western third. Other than lingering/token small PoPs across the east, drier conditions are expected tonight, with generally above-normal temperatures. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... As of 1207 AM Sunday: By Monday morning, the synoptic pattern will begin to amplify and evolve as upper ridging builds from the Southern Plains into the Lower Mississippi Valley. At the same time, a potent trough and associated closed upper low will be diving down the Pacific Coast and into the Great Basin. The building ridge will in turn shunt broad upper troughing along the East Coast offshore by Monday night with the coastal low shifting farther east as well. This will bring an end to persistent cloudiness, gusty winds and showers across the area with rising heights supporting a warming trend to start the week. Afternoon highs are forecast to climb back into the mid 70s to low 80s both Monday and Tuesday. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... As of 1224 AM Sunday: Heading into mid week, guidance is in good agreement that a northern stream trough will dive down the eastern flank of the upper ridge and into the Ohio Valley and New England. Another day of warm temperatures will continue on Wednesday with mid 70s to low 80s persisting. A large surface high shifts over the Great Lakes on Thursday with a backdoor cold front dropping across the region, which should knock several degrees off high temperatures. The pattern becomes much more progressive by late week as the previously mentioned Great Basin trough ejects across the Great Plains. The upper ridge will also slide east, but will begin to flatten/weaken, which should keep temperatures from being too warm over the weekend. The pattern remains dry through much of the period, but there are some indications that rain chances may return late next weekend. A series of troughs is forecast to move into the Pacific Northwest on Saturday the evolution of which will dictate the late weekend forecast. Guidance diverges as to how the pattern unfolds with some members digging a more potent trough across the Southern Plains into the Deep South while other members are less amplified. Will leave the forecast in line with the National Model Blend for now until guidance comes into better agreement. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... At KCLT: A band of (mostly) light/moderate rain and associated low cigs associated with a developing cyclone off the Southeast Coast will continue to gradually move toward KCLT from the east through daybreak, with tempo -RA and low VFR conditions forecast from 08-11Z, followed by a few hours of categorical -SHRA, before precip gradually tapers off through late morning. MVFR cigs are also forecast to settle in around daybreak, with little improvement expected through the day. Also cannot rule out at least a brief period of IFR cigs during late morning, but this will depend upon how persistent any rainfall becomes. At the other TAF sites: low VFR/MVFR cigs are expected to reach KHKY after sunrise, while tempo MVFR visby is forecast around sunrise at KAVL, but VFR is otherwise forecast at the TAF sites through the period. Rain could spread as far west as KGMU/KGSP later this morning, but the chance is only 20% at these sites, and any mention of precip is therefore omitted for now. Winds will remain N/NE at 10-13 kts at most sites through the period, with some gusts of 20-25 kts possible later this morning into the afternoon, particularly at KCLT. The exception will be at KAVL, where generally light N winds are anticipated. Outlook: Mostly VFR conditions are expected to return region-wide on Monday and persist thru at least the middle of next week, although there will be some potential for mountain valley low stratus and/or fog each morning. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...TW NEAR TERM...JDL SHORT TERM...TW LONG TERM...TW AVIATION...JDL