Area Forecast Discussion
Issued by NWS Wilmington, OH
Issued by NWS Wilmington, OH
383 FXUS61 KILN 031834 AFDILN Area Forecast Discussion National Weather Service Wilmington OH 234 PM EDT Wed Sep 3 2025 .SYNOPSIS... Widely scattered showers with an isolated thunderstorm are possible near/south of the Ohio River today, with the best chance for widespread showers and storms late tonight into early Thursday with a frontal passage. Yet another system will pass through the region Friday night bringing another round of showers and storms. This will be followed by early October-like temperatures for the weekend into early next week. && .NEAR TERM /THROUGH TONIGHT/... A deep upper level low over southern Ontario is the center point of an overall broad troughing pattern over the eastern 2/3 of the CONUS. The associated surface front will drop down from the upper midwest overnight, bringing lowering clouds and the best chance for widespread precip in a while late tonight. For the remainder of today, however, a weak embedded shortwave is skirting through the upper trough, with widely scattered showers and isolated thunderstorms affecting northern KY and south central Ohio through this afternoon/early evening. Overall instability remains low, so not expecting any storms to become strong/severe at this time. The showers/storms in the southeast should slowly diminish with the passing of the the shortwave and loss of diurnal instability. Precipitation onset with the advancing cold front will approach western Ohio/Eastern Indiana near/after midnight tonight and advance through the area, reaching roughly the I-71 corridor by 12z. Overnight lows generally in the upper 50s north with the frontal passage late, and lower 60s across the south. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... With the cold front passing through the SE forecast area on Thursday, this will bring lingering showers with the potential for embedded thunderstorms. The better chance for any strong storms will likely be east of the forecast area where forcing coinciding with diurnal instability will be more favorable. Highs on Thursday will generally range from the upper 60s across the NW behind the front, with lower 70s in the southeast, well below normal for the first week of September. For Thursday night, the mid Ohio Valley will be briefly quiet again as the first frontal system departs and the region awaits yet another shortwave through rotating around the still potent upper level low lingering across Ontario. Overnight lows under clearing skies will be in the upper 40s north and mid 50s south. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... A sharp mid-level shortwave will round the base of the longwave trough Friday and lift through the middle and upper Ohio River Valley Friday night. Ahead of it, a strengthening pressure gradient will cause an increase in the surface wind field. This will be especially noticeable Friday afternoon as the boundary layer deepens and becomes vertically mixed. In addition, the southwesterly flow ahead of the wave will bring a quick warm up for Friday. The disturbance arrives late, bringing a good chance of showers, mainly southeast of Interstate 71. Surface high pressure will begin to build into the region Saturday, eventually causing clouds to decrease by afternoon. Cold air advection will be in place through the rest of the weekend, with below normal temperatures and low relative humidity. Fair weather will continue Monday as the high moves overhead. Initial indications in the guidance is for the upper low over southeast Canada to weaken and lift away Tuesday and Wednesday, allowing increasing heights over the Ohio Valley along with warming temperatures. With a high-amplitude ridge building north across the Plains, dry weather is likely to continue through the end of the extended period. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... Most scattered shower and isolated thunderstorm activity will remain to the south and east of TAF sites today as an embedded shortwave is meeting with diurnal instability. The TAF locations are in a relative lull as the surface frontal boundary approaches from the western Great Lakes. Warm air advection this evening will be in play as thickening high and mid clouds ahead of shower and thunderstorm activity after 06z. MVFR ceilings and visibility in showers/storms possible in the 07-12z timeframe, with IFR ceilings expected in the wake of the showers/storms. Have included IFR CIGs at pretty much every location, improving to MVFR after about 15z. OUTLOOK...MVFR visibilities are possible Friday night with another round of showers and embedded thunderstorms. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...JDR NEAR TERM...JDR SHORT TERM...JDR LONG TERM... AVIATION...JDR