FXUS61 KILN 181904 AFDILN Area Forecast Discussion National Weather Service Wilmington OH 304 PM EDT Fri Aug 18 2017 .SYNOPSIS... An upper level disturbance will move through the region on Saturday bringing showers and thunderstorms to the region. High pressure will then be in place for Sunday and Monday. A cold front will approach the region on Tuesday bringing a return of precipitation to the area. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... The cold front and shower activity have moved east of the area therefore expect dry conditions for the remainder of the evening and through a large portion of the overnight hours. CAA cu will dissipate this evening, however there will be an increase in clouds during the overnight hours in advance of the next system. An upper level disturbance will begin to bring precipitation to northwest portions of the forecast area at the end of the near term. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... A decent upper level disturbance will move through the region on Saturday. The limiting factor with this system will be that there is not a lot of moisture with this system, however given the support with this system and model agreement, increased precipitation chances across northern portions of the region. Precipitation chances will be less along and south of the Ohio River. It looks like there will be an initial round of precipitation that works through the area Saturday morning, then there will also be the potential for additional thunderstorm development across extreme eastern portions of the forecast area with daytime heating during the afternoon. There is some instability during the day therefore went with a chance thunderstorm mention as well. Cannot rule out an isolated damaging wind gust or large hail across extreme eastern portions of the forecast area with the afternoon development, however the more likely scenario would be small hail and some gusty winds. Went close to conshort for highs which is close to the cool side of guidance values. With extensive cloud cover expected with this system and the timing of this system, believe that most locations will be limited to the upper 70s to low 80s. Locations along and south of the Ohio River where there will be less cloud cover and precipitation will see potentially higher temperatures around the middle 80s. Winds will pick up during the afternoon as the system begins to pass through and some wind gusts around 20 mph outside of thunderstorms will again be possible. Winds will quickly diminish during the evening hours and cloud cover will begin to decrease. This will allow for temperatures to drop down into the upper 50s to low 60s across the area. && .LONG TERM /SUNDAY THROUGH THURSDAY/... Models are in good agreement that a surface high pressure will be centered over the region Sunday morning. This will bring mostly sunny skies and seasonable temperatures in the mid to upper 80s. The center of the high will pull east of the region Sunday night, allowing a little of a return flow for Monday/Eclipse Day. There should be some cumulus development in this flow, but the clouds shouldn`t spoil the viewing. Kept the forecast dry, but there is a model or two that pops a shower on Monday. A more substantial chance of rain will develop Tuesday into Tuesday night as cold front swings through the Great Lakes and Ohio Valley ahead of a strong H5 s/w. 12Z models are a little slower with the system on Tuesday, so adjusted the timing back. The best chance of thunderstorms will looks like Tuesday afternoon into Tuesday night. Upped PoPs to likely to cover this system. Behind the front Wednesday, a cooler and drier airmass will begin to settle in for the later half of the week. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... Cold front and associated shower activity is east of the TAF sites therefore expect dry conditions for the remainder of the day. An upper level disturbance will approach the region tonight and work into the TAF sites on Saturday. Although there are dry low levels a decent upper level disturbance will allow for some shower activity across the region. Cannot rule out thunder, however expect thunder to be limited and therefore decided not to include at this time. Isolated wind gusts around 20 knots will be possible this afternoon and also tomorrow afternoon. OUTLOOK...Thunderstorms are possible on Tuesday. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...Novak NEAR TERM...Novak SHORT TERM...Novak LONG TERM...Sites AVIATION...Novak
