Area Forecast Discussion
Issued by NWS Wilmington, OH
Issued by NWS Wilmington, OH
143 FXUS61 KILN 140103 AFDILN Area Forecast Discussion National Weather Service Wilmington OH 903 PM EDT Wed Aug 13 2025 .SYNOPSIS... The threat for showers and thunderstorms will continue into tonight as a weak cold front drops south through the area. Thursday will feature slightly cooler and drier conditions before a warming trend starts on Friday and continues into the weekend. && .NEAR TERM /THROUGH THURSDAY/... Convection has mostly come to an end across the ILN CWA, but not before one anchored storm produced about 2.5 inches of rain in southwestern Greene County OH. Surface dewpoints are not really dropping too quickly as the cold front slowly moves south, though the higher values (lower 70s) are limited to just the southern sections of the forecast area. Precipitable water values have been gradually decreasing with time from north to south, though the 00Z KILN sounding (1.83") was still on the more humid side of this air mass. Notably drier air is noted on WV satellite across northern Ohio and much of Indiana. Fog remains the main concern overnight, particularly for areas with slightly greater moisture in the southern half of the forecast area. Some patchy dense fog could develop in south-central Ohio and northeast Kentucky. Previous discussion > Mid level westerlies push south thru the Great Lakes and into the Ohio Valley as a long wave trof settles across the southeast Canada and northern New England. An embedded weak shortwave along with moderate instability will promote the development of scattered convection ahead of a slow moving surface front. Shear is very marginal but PWAT values remain high today - especially across the southeast half of the area. ILN/s 12Z sounding observation recorded a PWAT of 1.87 inches. Marginal shear and DCAPE will limit the severe weather threat with the main threat being heavy rain and localized flooding through evening. The weak cold front will continue progressing south through the area settling south of the Ohio River later tonight and precipitation chances will come to an end. Winds shift to the north/northwest behind the front. Forecast lows drop to readings ranging from the middle 60s along and west of I-75 to near 70 over the southeast. There is a signal for fog over the southeast - so will include a mention of patchy fog overnight into early Thursday. && .SHORT TERM /THURSDAY NIGHT/... West-northwest mid level flow across the area with a rather weak embedded shortwave rippling thru the Ohio Valley during the afternoon. Marginal instability with BL CAPE values approaching 1000 J/KG in the post frontal zone will allow for an isold threat for a shower or thunderstorm over the southeast mainly during the afternoon. Temperatures will not be quite as hot with highs from the mid 80s northwest to the upper 80s southeast. Any diurnally driven storms to end quickly Thursday evening with surface high pressure building across the Great Lakes. Expect mainly clear sky conditions with the potential for valley fog. Low temperatures drop into the mid and upper 60s. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Large scale quasi-zonal flow continues over the Great Lakes region with a broad ridge over most of southern CONUS. The feature of interest, a closed low/ trough digging down into southern Canada, may be able to dig far enough south to influence our sensible weather down near the Mid-Atlantic region, though guidance struggles with whether this feature will be able to break down the ridge enough to impact us. Looking a bit closer, as the trough approaches on Friday, we remain dry, though with continued hot and muggy conditions. This trend continues on Saturday, though perhaps a few degrees warmer. By Sunday into Monday, we begin to feel the influences of the trough a bit more, with increased cloud cover and an increased chance for PoPs. Right now, the blend holds PoPs along and north of I-70, though this may shift latitudinally depending on how things progress. Chance PoPs remain in the forecast as we head into early week, with ensemble guidance stalling the frontal boundary out near our region. Outside of this system, the other item of note for the extended will be the warming temperatures and increasing humidity. Head index values once again begin to tickle the upper 90s to (possibly) low 100s near the end of the weekend and into the start of the working week. Confidence is medium on this right now and will hinge on how the trough progresses. However, still worth noting for planning purposes. && .AVIATION /01Z THURSDAY THROUGH MONDAY/... Chances for showers and storms will come to an end over the next few hours. Dry conditions are then expected through the rest of the TAF period. The main concern overnight is for fog development, with MVFR to IFR fog expected at the TAF sites during the early morning hours. LIFR is expected in the valley at KLUK. Visibilities are expected to improve by 13Z-14Z. VFR conditions are then expected through the day on Thursday, with northeast winds of less than 10 knots. OUTLOOK...No significant weather expected. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...AR NEAR TERM...Hatzos/AR SHORT TERM...AR LONG TERM...CA AVIATION...Hatzos