Area Forecast Discussion
Issued by NWS Wilmington, OH

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000 FXUS61 KILN 081739 AFDILN Area Forecast Discussion National Weather Service Wilmington OH 1239 PM EST Fri Dec 8 2017 .SYNOPSIS... High pressure and dry conditions will be present today into tonight. An area of low pressure and associated cold front will move across the region on Saturday bringing snow to the area. Dry conditions will return for Sunday before another system approaches on Monday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... No precip is occurring today with surface high pressure extending along the Ohio River aligned along the east flank of an upper trough. Coverage of mid and high clouds will vary across the region, with more cloud cover across the Scioto Valley developing in a plume of moisture advecting on the jet stream to the southeast, and less coverage across locations northwest of I-71. With southerly flow and very weak WAA, temperatures will probably rise today into the 30s across the region, though it may be tough to attain those readings after a chilly start in the teens. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... Most of the mid and high clouds will move out of the area by evening, leaving mostly clear skies for several hours tonight. With dry air in place and mostly clear skies expect temperatures to drop off quickly this evening and into tonight. The model blends (Superblend, NBM) are well above guidance values for low temperatures for tonight. Went much closer to guidance values than the blended solutions as the guidance values seem more realistic given the scenario. Could see values even getting colder than currently forecast if clouds hold off long enough. Temperatures will start to rise across western portions of the forecast area late in the overnight hours as clouds start to move into the region in advance of a cold front. Models are in pretty good agreement on holding off precipitation until the day on Saturday and therefore slowed precipitation onset and have Friday night dry. At the start of the day on Saturday there is quite a bit of dry air in the low levels and therefore it will take a little bit of time for saturation to occur. A cold front will move through during the day on Saturday with the best upper support across northern portions of the forecast area and this will be the focus of the best chance of snow for the first half of the day into the early afternoon hours. As the afternoon progresses however, winds off of Lake Michigan become more favorable for snow showers across an area from generally northwest of Interstate 71 and near/a little south of Interstate 70. Snow ratios will be a little higher later in the day. In general expect a half inch or less of snow along and south of the Ohio River. The Scioto River Valley will generally see a half inch to an inch. Northwest of Interstate 71 and north of Cincinnati will likely have the highest totals in the one to two inch range. With the scattered and small band nature of the snow some locations will have the possibility to see slightly less or slightly more than their general amounts. Winds will also pick up Saturday afternoon with some wind gusts around 20 to 30 mph. This will add to some of the visibility reductions with the snow that does occur. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... Snow showers at the beginning of the period will taper off as the the low level flow backs. Warm air advection will ensue with temperatures getting back to near normal by Monday. Monday night into Tuesday another short wave will drop into the mean trough and then quickly swing east. Associated surface low will pass north of the forecast area, so only a low chance of any precipitation with this in the far northern counties. But strong cold air advection in the wake of the low will result in lake enhanced snow showers late Monday night into Tuesday. There will likely be early highs Tuesday with readings dropping in the afternoon. Temperatures will then plummet to 10 to 15 Tuesday night. Yet another, albeit weaker, short wave will pass across the Great Lakes Wednesday night into Thursday. Once again, chance of precipitation will be greater to the north of the area, but cannot rule out some snow showers in northern counties. Temperatures will slowly moderate ahead of this system. && .AVIATION /18Z FRIDAY THROUGH TUESDAY/...
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VFR conditions through the early part of the forecast will deteriorate on Saturday as Great Lakes low pressure triggers light accumulating snow. Expect mid and high clouds today with south to southwest winds under 10 knots. For tonight, clouds will thicken ahead of the system approaching from the northwest, while ceilings stay VFR. On Saturday, MVFR ceilings may develop at DAY CVG and LUK after the boundary layer nears saturation under the light snow. DAY is likely to experience MVFR visibility as well, being closer to the bulk of moisture and precip with this system. Other sites ILN CMH and LCK may see MVFR after 18z Saturday with the light snow. All sites should see wind speeds increase in the circulation around the low, with gusts near 20 knots from the southwest. Look for improvement back to VFR at CVG toward the end of their 30 hour TAF as drier air starts to work in behind the low and its associated cold front. OUTLOOK...MVFR ceilings and visibilities are possible Saturday afternoon and evening, and again Monday into Tuesday.
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&& .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...Novak NEAR TERM...Coniglio/Novak SHORT TERM...Novak LONG TERM... AVIATION...Coniglio is the U.S. government's official web portal to all federal, state and local government web resources and services.