Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 290045 AFDCTP Area Forecast Discussion National Weather Service State College PA 745 PM EST Mon Nov 28 2016 .SYNOPSIS... A broad storm system centered over the upper plains and midwest will push a cold front through the commonwealth on Tuesday. A widespread rain will fall late tonight and Tuesday. A second cold front will follow for midweek. More rain and mild temperatures will occur before cooler air and lake effect snow showers return for the end of the week. && .NEAR TERM /UNTIL MIDNIGHT TONIGHT/... High clouds will lower and thicken through midnight. But, rain should remain off to the west until close to midnight. Temps will fall very little in the evening in the west. But, wind may go calm/light and variable in the east. && .SHORT TERM /MIDNIGHT TONIGHT THROUGH TUESDAY NIGHT/... Temps may rise late tonight as a strong srly LLJet moves in just ahead of the cold front. The stability provided by nighttime will keep the wind from becoming too strong/gusty in the central and east. However, the hill tops of the west may gust into the l20s by morning. We typically do not get all that gusty in these south winds ahead of a front - even in the north. It is usually more of a problem for the downslope areas of far NWrn PA and wrn NY. The latest timing is very solid with prev forecasts and guidance. QPF also solid with 0.25-0.75 inches out of this first FROPA. One small tweak was to delay the exit of the precip from the SErn half of the area on Tues aftn. Downstream ridge over the western Atlantic and New England does not move much and pumps up a little. Thus, the rain may amount to a little more in the SE. MOS guidance and llvl mstr plots indicate a low cloud deck forming and sticking in the nrn mtns and perhaps the Laurels after the front goes by. Some breaks are expected though, as it will still be daylight and some mixing is expected. But, it may then be a dismal/damp but mild night Tues night. A wave develops along the old front over the Deep South while another front spins off-east of the midwestern storm center. Will keep chc-low likely pops in for the very last part of Tues night in the west. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Another significant wave forming on a trailing cold front will ride up the west side of the appalachians and spread another slug of rain up over the area by early Wednesday. Heaviest rain looks to be over the SW through midday then shift to the SE in the afternoon (along axis of highest PWAT air) where a period of moderate rain is likely. By late week, the upper low that had been hanging out over the western Great Lakes morphs eastward across southern Canada, ushering in a prolonged period of cold NW flow aloft and breezy conditions at the surface - starting with a shortwave rotating around the base of the low on Thu. The airmass doesn`t look especially cold (fairly close to seasonal normals), but the cold air flowing over the still quite warm lakes will be enough to provide an extended period of widespread cloudiness and frequent lake effect snow showers over the the NW mountains down into the Laurel Highlands, possibly lasting all weekend long as the pattern becomes slowly less amplified. Much divergence in model solutions for early next week brings a low confidence forecast during this period. The GFS is suggesting a cold frontal passage while the ECMWF shows a very amplified pattern. Went mainly away from the EC, but did include chance for precip Sun night into Mon. Temps peak Wed with highs back up into the 50s/lower 60s. Thu will be a transition day back to colder temps with late week/weekend just a shade below normal. && .AVIATION /01Z TUESDAY THROUGH SATURDAY/... Expect lowering CIGs overnight, as a warm front approaches from the Ohio Valley. A core of strong southerly winds aloft will sweep across the region Tuesday morning, accompanied by a period of rain and low CIGs. In addition, the combination of the strong winds aloft and relatively light wind a ground level will yield widespread LLWS conditions. Low CIGs and VIS are expected from about 06z-18z in many locations. LIFR is possible behind the rain in the low CIGs over the N on Tues aftn/eve. A brief break in pcpn should occur until the next front moves in on Wed. Much colder air and prolonged NW flow will follow the second front. Outlook... Tue...Low cigs/rain, mainly in the morning W and all day in the SE. Wed...Rain/low cigs possible. Thu-Sat...SCT SHSN Ocnl IFR in BFD-JST. ISOLD SHSN AOO-UNV-IPT. VFR Elsewhere. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Dangelo NEAR TERM...Fitzgerald/Dangelo SHORT TERM...Dangelo/Fitzgerald LONG TERM...RXR AVIATION...Dangelo/Fitzgerald is the U.S. government's official web portal to all federal, state and local government web resources and services.