Area Forecast Discussion
Issued by NWS Wilmington, OH
Issued by NWS Wilmington, OH
653 FXUS61 KILN 291334 AFDILN Area Forecast Discussion National Weather Service Wilmington OH 934 AM EDT Fri Aug 29 2025 .SYNOPSIS... High pressure will build into the region in the wake of a cold front today. This high will offer dry weather through the weekend into early next week. A southerly flow on the back side of this retreating high marks an increase in moisture and a return of rain chances Tuesday, increasing as we head into mid week. && .NEAR TERM /THROUGH TONIGHT/... Morning update... This morning`s 12Z ILN sounding reveals a steep inversion near the surface supporting ground fog in many places, however, the very shallow nature of the inversion allowed the fog to clear in many places quite quickly. However, the fog associated with the band of clouds across Dayton and Columbus has been a bit slower to clear. The patchy dense fog has mostly dissipated this morning, but the band of low clouds remains, slowly dropping to the southwest this morning. As daylight increases, southward advancement of the clouds will slow and eventually mix out later this morning. Otherwise, expect a gradual increase in fair weather cumulus into the early afternoon. Previous discussion... The eastern CONUS was dominated by a mean trof with a large mid and upper level low centered over southeast Canada - placing the Ohio Valley in a northwest flow regime. An embedded shortwave pivoting southeast thru the eastern Great Lakes will will push a surface cold front south across the region early this morning. Expect low clouds and patchy fog to develop in the post frontal environment in the pre-dawn hours. The best coverage of clouds will occur across the northern part of the area. There is some uncertainty with how far south and how extensive the post-frontal clouds will be across the region. These clouds will decrease this morning as drier low level air advects into the region. Also, some high level clouds will stream into the area late morning into the aftn. Temperatures will be 7-10 degrees below normal with highs from 70 north to near 80 south of the Ohio River. && .SHORT TERM /SATURDAY/... Northwest flow aloft with surface high pressure settling into the region. High level clouds early this evening are expected to thin out leaving mostly clear sky conditions. In the dry airmass cool temperatures expected to drop to lows generally in the mid and upper 40s with lower 50s along and south of the Ohio River. Although these temperatures will be cool they look to be about a category above records. Record lows for 8/30 are 43 at Dayton, 45 at Columbus, and 45 at Cincinnati. Saturday looks to be a dry (low humidity), sunny, and seasonably cool day. After a cool start highs are expected to top out from the lower 70s north to the upper 70s south. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... On Saturday evening, an upper low will be moving east into the Canadian Maritime provinces, but broad troughing will remain in place across much of the eastern CONUS. A weakness in the upper flow will develop by early in the week, with the upper level height pattern becoming nebulous. By Wednesday, however, deep troughing is expected to develop just upstream of the Great Lakes -- setting up a pattern favorable for precipitation over the Ohio Valley and adjacent regions on Wednesday and Thursday. Sunday and Monday are expected to remain dry, with some semblance of surface high pressure still in place over the region. The air mass will be initially fairly dry (with precipitable water values of around a half inch on Sunday) with moisture beginning to slowly increase on Monday. Precipitation chances will enter the forecast on Tuesday, with southerly boundary-layer flow beginning to bring a more pronounced increase in moisture to the area. The forcing will remain somewhat nebulous, though, so chances will be kept in the 20-30 percent range. Rain looks most likely on Wednesday and Thursday, with forcing becoming more well-defined ahead of the developing upper trough. Looks like there may be just enough instability for thunder, but the soundings are somewhat moist, with poor lapse rates and unimpressive surface temperatures keeping CAPE values fairly low. In terms of temperatures, a gradual warming trend is expected from Sunday through Tuesday. Sunday will remain about 4-8 degrees below normal, with highs in the mid 70s to around 80. Monday and Tuesday will have highs in the upper 70s to lower 80s. Highs will decrease slightly on Wednesday, with precipitation expected, and then fall even further behind a cold front on Thursday (upper 60s to mid 70s). && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... A surface cold front which has progressed to a position near the Ohio River will continue pushing south of the area this morning. Low clouds and patchy fog have developed in the post frontal environment across portions of central Ohio . Have IFR conditions forecast at KDAY and KLUK with MVFR conditions at KCMH and KLCK. The fog and stratus will improve this morning with a VFR cumulus deck developing. High level clouds will stream into the area late morning into the afternoon accompanying the cumulus clouds. The cumulus clouds will dissipate late in the day and high level clouds will thin out this evening leaving mostly clear skies tonight. The clear skies and light winds will likely lead to river valley fog overnight. Northwest winds at 5 to 8 kts will increase to about 10 kts this morning and become more northerly. Winds will then veer to the northeast and decrease to 5 kts or less tonight. OUTLOOK...No significant weather expected. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...AR NEAR TERM...McGinnis/AR SHORT TERM...AR LONG TERM...Hatzos AVIATION...AR