Area Forecast Discussion
Issued by NWS Wilmington, OH

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000 FXUS61 KILN 171740 AFDILN Area Forecast Discussion National Weather Service Wilmington OH 1240 PM EST Sat Feb 17 2018 .SYNOPSIS... An area of low pressure will move just southeast of the region today while an upper level disturbance moves toward the Great Lakes. The upper level disturbance will move away from the region tonight. High pressure will allow for dry conditions on Sunday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Observations just to our west/southwest is showing more snow at the onset of precipitation. It now looks like there will be more snow than rain early on, especially along and north of the Ohio River. Believe there should be more of as transition to rain as the afternoon wears on, especially closer to the Ohio River. As a result of more snow, have allowed for a slushy snow accumulation of a half inch or less roughly between the Ohio River and I-70. Highs now will range from the mid to upper 30s. Previous discussion---> An upper level s/wv will approach the Great Lakes region from the west today. The combination of a developing low to mid level jet and upper divergence from the RR Quad of an enhancing upper level jet will bring likely to categorical PoPs to much of the forecast area. The northern periphery of the advancing precipitation field may start briefly as snow or a rain/snow mix. Then, it should transition to mostly rain by the mid afternoon hours. Little snow accumulation is expected. Highs will range from the upper 30s to around 40. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/... Precipitation will still be ongoing at the start of the near term with an upper level disturbance moving across northern portions of the region. This feature will allow for some snow to mix in with the rain. With temperatures still in the 30s do not expect much in the way of accumulation. Precipitation will then taper off overnight, however some cloud cover will remain. High pressure will then work into the region for the day on Sunday. WAA on Sunday and plenty of sunshine will allow temperatures to climb into the middle 40s to the lower 50s. Went close to guidance for temperatures on Sunday. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... A warm front will lift north across the area late Sunday night into Monday morning. This will result in early lows Sunday night and then rising temperatures. In addition, showers will develop and occur ahead of the warm front. Initially, better chance of precipitation will be in the western counties but then this shifts across the northern counties on Monday. In amplified upper level flow, frontal boundary to the west of the region will be slow to move into the area. GFS has been more progressive with this front, and while this cannot totally discounted, have leaned towards slower ECMWF which has some support from the Canadian. Rainfall will be focused closer to the front on Tuesday with the greatest rainfall threat in the northwest counties. This will then transition to more of a post-frontal precipitation event which will translate across the region Tuesday night into Wednesday night. Precipitable water is forecast to be very high, greater than 200 percent of normal, so showers could be quite efficient rain producers. The ground will be wet from previous rainfall, so the threat of additional flooding is still a concern. Ahead of the front, the airmass will be very warm and record temperatures are possible on Tuesday. Given current frontal timing, after morning highs temperatures will be falling during the day Wednesday. High pressure will briefly build in for Thursday. But the chance of showers will return on Friday as another warm front pushes into the area. Temperatures will be slightly above normal for the latter part of the week. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... An upper level disturbance will move into the region by this evening. Ahead of it, widespread precipitation due to low level and upper level jet dynamics can be expected for most of the afternoon hours. The widespread precipitation shield is then expected to exit the eastern forecast area between 21Z and 00Z. It now appears that the precipitation will either be snow or a rain/snow mix before some warming in the low levels, along with the lack of active ice nuclei aloft, bring the threat of light rain and snow, or even some patchy drizzle. Ceilings and visbilities will drop into the IFR categories with the main precipitation. For tonight, upper level disturbance moves east this evening. This will keep a least of chance of rain/snow/drizzle going until subsidence develops in its wake. IFR ceilings and MVFR visbilities should transition to MVFR ceilings and VFR visbilities overnight. In fact, clouds may scattered late across the western terminals. West to northwest winds will lighten as surface high pressure builds into the region. On Sunday, high pressure will move east of the region. Winds will shift to the southeast/south. Residual low clouds will eventually shift east and/or dissipate with only FEW-SCT high clouds expected thereafter. OUTLOOK...MVFR/IFR ceilings and MVFR visibilities possible on Monday. MVFR conditions possible at times from Monday night through Thursday. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...Hickman NEAR TERM...Hickman SHORT TERM...Novak LONG TERM... AVIATION...Hickman is the U.S. government's official web portal to all federal, state and local government web resources and services.