Area Forecast Discussion
Issued by NWS State College, PA

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464 FXUS61 KCTP 211006 AFDCTP Area Forecast Discussion National Weather Service State College PA 506 AM EST Tue Feb 21 2017 .SYNOPSIS... An extended period of mild weather with well above normal temperatures will continue through the end of this week. A weak cool front will push through the state late Today and Tonight night. A stronger cold front accompanied by a few rounds of showers is expected for Friday into Saturday, followed by a shot of colder air with gusty westerly winds over the upcoming weekend. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Expect fair weather early today with increasing cirrus, as upper level ridge axis shifts eastward from the Grt Lks. At the surface, a dying back door cold front with shallow cool air continues to sit over the central mountains at 0930Z (just east of the Interstate 99 and RT 219 corridors), with markedly lower dewpoints behind this boundary across the eastern half of the state. Much thinner cirrus and the drier dewpoint air has resulted in the best radiational cooling across the eastern counties, where min temps will dip into the mid and upper 20s. Elsewhere, temps to start the day will be in the 30s (to near 40F across portions of the Laurel Highlands where the thickest clouds and a 5-10kt serly breeze will will be found). A weakening front and the associated shearing upper shortwave will bring increasing high clouds to the area today. This (following the decent amount of radiational cooling we experienced overnight) will likely result in max temps several degrees cooler than those on Monday. A few showers may work into the northwest mountains toward evening, ahead of the weakening shortwave over the Grt Lks. Otherwise, confidence is high for another dry day across the remainder of central Pa. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... The subsiding branch of a 300 mb, 85 kt jetlet (and associated weak sfc cool front) sags south across the commonwealth overnight tonight. The best chc for Isolated to scattered light showers should be prior to 08Z Wednesday. Plenty of relatively thick mid level clouds will linger tonight, keeping min temps well above normal and in the mid and upper 30s (NE) to the lower-mid 40s in the southern and western portions of the CWA. Sunshine, mixed with varying amounts of mid and high clouds will occur on Wednesday. Considering the mild start to the day, and GEFS mean 850 mb temps of 7-8C, we should see max temps easily reaching the upper 50s to lower 60s which is very close to the latest Nat`l Blend of Models guidance. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... Gradually milder temperatures will return for the extended period as no genuine cold air push is in sight. High temperatures in general will be 10 to 20 degrees above normal with min temperatures mainly above freezing. Deepening Swrly flow for the second half of the week will cause temps to rebound to well above normal (and perhaps near record levels in some locations). The overall, large-scale pattern becomes more amplified late in the week as a system over the central plains deepens and lifts into the Great Lakes. Clouds will increase Thursday and Friday with warm front lifting through, and bringing increasing rain chances heading into the weekend, followed by a shot of colder/windy conditions Saturday through Sunday. && .AVIATION /10Z TUESDAY THROUGH SATURDAY/... Predominately VFR into tonight under increasing high to mid level clouds ahead of weakening frontal system approaching from the Midwest. MVFR conditions are possible with light rain showers late tonight into Wednesday morning across the NW 1/3 of the airspace. Outlook... Wed...A.M. sub-VFR/possible NW 1/3; otherwise VFR with light rain showers in spots. Thu...Sub-VFR possible with chance rain showers. Fri...Sub-VFR possible with rain showers likely Friday night. LLWS probable. Sat...Strong cold FROPA with sub-VFR and possible thunderstorms. Gusty post-frontal NW winds with snow showers NW 1/3 Saturday night. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Lambert NEAR TERM...Lambert SHORT TERM...Lambert LONG TERM...Lambert/Gartner AVIATION...Steinbugl is the U.S. government's official web portal to all federal, state and local government web resources and services.