Area Forecast Discussion
Issued by NWS Greer, SC
Issued by NWS Greer, SC
046 FXUS62 KGSP 060012 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 812 PM EDT Tue Aug 5 2025 .SYNOPSIS... A wedge of cool and moist air will linger through much of the week before a potential coastal low erodes the wedge this weekend. Although a warming trend is expected to begin Wednesday, below normal high temperatures are expected to continue through this weekend. Rain chances remain each day through this week. && .NEAR TERM /THROUGH WEDNESDAY/... As of 5:35 PM EDT Tuesday: Shower coverage has shifted NE over the past few hrs as rain rates have also diminished across our area. In addition, we`re actually seeing some clearing over far western NC, although we remain socked in elsewhere. We still expect a lull in precip activity thru the evening as isentropic upglide weakens over our area. Otherwise, a sprawling sfc high will slowly shift out of southeast Canada and into New England, which will keep a CAD pattern in place across the western Carolinas and northeast Georgia with an inverted sfc ridge extending down the lee of the mtns. Heading into tonight, the latest suite of CAMs remains in decent agreement that a weak impulse swinging through the base of the broad upper trof should provide sufficient forcing and renewed isentropic ascent atop the wedge to initiate another batch of showers, especially along the I-85 corridor. A slight uptick in elevated instability atop the cold dome would also support efficient precipitation rates with locally heavy rates possible. Additional minor/nuisance flooding will be possible thru the overnight and into the morning, especially if any heavier showers occur across areas that received heavy rain over the last day or so. Forcing becomes more nebulous during the day tomorrow in the wake of the passage of the aforementioned impulse. The result will be the potential for a somewhat drier period by late morning into the afternoon after morning showers push out of the area. Rain chances will become focused outside of the wedge across the southwest mtns where more traditional diurnal pulse convection is expected. Tempera- tures will also warm tomorrow in the absence of widespread showers during peak heating, but will remain well below normal in the low to mid 70s. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... Key Messages: 1) Cold air damming will slowly weaken through this period, but high temperatures will remain below normal. 2) Rain chances continue through the period, with a transition to more of a diurnally-driven convective regime. As of 1150 am EDT Tuesday: Surface high pressure positioned over the northeastern states will maintain easterly flow and ridging across our area for Wednesday night through Friday. This will act to keep the wedge in place, but it should slowly weaken through time. Highs should climb back into lower 80s Thursday and Friday in the Piedmont and mountain valleys, which is still well below climo. Rainfall will also trend down over the next couple days with a more diurnal pattern setting back up. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... Key Messages 1) Weak cold air damming lingers through the weekend. 2) Confidence is low regarding potential coastal low impacts this weekend. 3) Forecast temperatures slowly increase but remain below normal until at least Monday. As of 1205 pm EDT Tuesday: A similar pattern to the short term period will persist into the weekend. A weak low off the southeast coast may bring some moisture into our southeastern areas, but otherwise expect a diurnal shower pattern with highs remaining below climo. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... At KCLT and elsewhere: Restrictions will continue across the fcst area thru the 00z taf period as a cold/cool air damming pattern remains in place across the region. Widespread low stratus will keep ceilings predominately IFR thru the taf period, although the Upstate terminals and KAVL will likely improve to MVFR sometime during the afternoon tomorrow. In addition, periods of LIFR will also be possible mostly within any heavier showers overnight and into the morning. A lull in shower activity/coverage is expected to continue thru the evening before another round of showers moves over the area overnight and into the morning. This will bring another round of visby restrictions to most terminals. Otherwise, mist/patchy fog will keep visby in the low VFR to MVFR range outside of showers. Shower coverage will diminish again later tomorrow morning, however isolated to sct thunderstorms will be possible during the afternoon, especially over the mtns. Outside the mtns, winds will remain steady and from the NE thru the taf period. At KAVL, winds will be light and VRB thru tomorrow morning. They should pick up marginally from the ESE tomorrow afternoon. Outlook: The cool-air wedge pattern is expected to persist over our area thru the workweek keeping rain chances and periodic restrictions in the fcst. Embedded thunderstorms will also be possible each after- noon and evening but confidence wrt locations and timing is low. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...SCW NEAR TERM...JPT/TW SHORT TERM...SCW LONG TERM...SCW AVIATION...JPT