


Area Forecast Discussion
Issued by NWS Wilmington, OH
Issued by NWS Wilmington, OH
061 FXUS61 KILN 021026 AFDILN Area Forecast Discussion National Weather Service Wilmington OH 626 AM EDT Tue Sep 2 2025 .SYNOPSIS... High pressure shifting east into the mid Atlantic will keep generally dry conditions across the region into midweek, although a weak low passing south of the area could initiate a few daytime showers today and again on Wednesday. The better chance of rain will come as a cold front pushes through the region late Wednesday night into Thursday morning. After a brief warm up, this front will usher in the return of unseasonably cool temperatures late in week into this weekend. && .NEAR TERM /THROUGH TONIGHT/... A weak mid level impulse will pass to our south from the mid South into the TN Valley today. This will induce a weak low to our south with an inverted surface trof extending north into the Ohio Valley. High pressure center over the eastern Great Lakes at the beginning of the period will move into the mid Atlantic. High pressure over the eastern Great Lakes will build to a position along the Eastern Seaboard. Forcing and moisture are rather marginal, but an isolated shower cannot be ruled out mainly south of the Ohio River this aftn. Otherwise, expect a few more high based cumulus clouds. Highs will generally be in the lower 80s. && .SHORT TERM /WEDNESDAY/... Any isolated showers that develop south of the Ohio River this aftn will dissipate with sunset due to a lack of forcing. Expect mostly clear sky conditions to develop overnight with lows from the lower 50s to the upper 50s. Mid and upper level flow characterized by a long wave trof over the Eastern Conus. A deep low to drop from central Canada southeast into the western Great Lakes. An associated surface low will move into northwest Indiana Wednesday afternoon with associated pcpn staying west of the area thru the daylight hours. At the same time a weak embedded shortwave moving thru the trof will induce a weak wave to our south. An inverted surface trof and marginal instability may result in an isold shower and perhaps a thunderstorm over the southeast Wednesday afternoon. Highs will generally be in the lower 80s. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... On Wednesday evening, a deep upper low will be centered over Lake Superior, with a surface low near James Bay. A cold front will extend from this surface low south through Michigan, then southwest into Indiana and Illinois. This cold front will move east through the ILN CWA during the first half of the day on Thursday, bringing a solid chance of precipitation to the area -- with a few embedded thunderstorms also possible. Based on frontal timing and poor expected destabilization, chances for strong storms on Thursday appear limited, and perhaps greater off to the east and southeast of the ILN forecast area. Regardless of any convective threat, much of the forecast area will be likely to get a decent rainfall of a quarter inch or greater. The Thursday cold front will represent the greatest chance of precipitation through the extended forecast period. However, there will likely be a secondary cold front moving through the area some time Friday into Saturday, as another shortwave moves through the Great Lakes on the southern periphery of the rather substantial upper low. Forecast certainty is still not perfect regarding the timing of this secondary front, and also on the overall timing of the whole system moving far enough to the east / northeast to bring high pressure into the Ohio Valley. Regardless, some light rain will be possible some time late Friday into Saturday. By later Saturday into Sunday, dry weather is expected -- and will likely continue into early next week. One other item to note is that an increasing pressure gradient on Friday -- with low pressure over the Great Lakes -- will lead to some wind gusts into the 20-25 knot range over the ILN forecast area during the afternoon. Possibly some room for this to increase a little, if some of the stronger model solutions verify. Much cooler temperatures are expected behind the front on Thursday, with a very slight rebound on Friday in advance of the next wave. After that, an anomalously cool and dry air mass will move into the area, with highs in the mid 60s to mid 70s over the weekend. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... Surface high pressure centered over the eastern Great Lakes builds east to the east coast today. A weak inverted trof is expected to develop into the Ohio Valley this aftn today north of a weak low. Mostly clear skies this morning may lead to a brief MVFR vsby restrictions for fog at KLUK. Otherwise, just expect some scattered cu development again through the day, with any isold showers that develop in response to the inverted trof staying south of the TAF sites. Skies become mostly clear this evening with only some high level clouds spilling into the area. The threat for river valley fog at KLUK looks better tonight with some increase in low moisture and an east to southeast light low level flow. OUTLOOK...MVFR ceilings and visibilities are possible Wednesday night into Thursday. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...AR NEAR TERM...AR SHORT TERM...AR LONG TERM...Hatzos AVIATION...AR