Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 212347 AFDCTP Area Forecast Discussion National Weather Service State College PA 747 PM EDT Fri Oct 21 2016 .SYNOPSIS... A cold front moved southeast through Pennsylvania Friday. Blustery northwest winds will usher in much colder air overnight and Saturday. Occassional like showers are possible through Saturday night especially across the mountain areas and the north. The first bout of lake effect and upslope rain and snow showers are possible over some of the higher ridge tops. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Made adjustments for the timing of the colder air which is alreading sweeping into the lower Susq Valley and minor tweaks to winds and dew points for the overnight period across the region. Light showers or drizzle continues mainly over the western and northern zones associated with the upper level trough with a few spotty showers elsewhere. This is expected to coninute to diminish overnight as the trough slowly pushes east. Flooding abated and the smaller streams are receding with water moving down the mainstem rivers now. No additional flooding anticipated. Something to consider for later tonight into early Saturday will be the potential for the season`s first accumulating snows over the RIDGETOPS of the Laurels and Northern Mountains. The guidance has been persistent in bringing the coldest 850mb temps of the season to date in behind our deep upper low. The potential for a light slushy inch over the ridges is shown in the HRRR and NCAR ensemble. The deterministic NAM and GFS are showing chances for light accums over larger more general areas of the west and north, this seems too generous given surface temps will be relatively warm. Am thinking we will try to emphasize a light slushy accum over the higher elevations only. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/... A cool and unsettled day is in store Saturday as persistent northwest flow and progressively cooler boundary layer air is forced into the region. In fact 850 mb temps remain below 0 throughout the day throughout central PA...and we`ll certainly be looking at a few wet snowflakes mixing in at times with some of the showers over the higher terrain of the northwest and northern mountains. Under scenarios such as what we expect, the best chance for measurable precipitation usually favors these western and northern higher terrain areas with little more than sprinkles elsewhere. Maxes will range from the lower 40s northwest to the lower to middle 50s southeast. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... As the surface and mid level systems track through eastern Quebec, a broad cyclonic/northwest flow pattern will continue into early next week. Models forecast lingering deformation or lake-enhanced pcpn to come to an end by early Sunday morning. Gusty winds will should weaken a bit with peak gusts not as strong as Saturday. Focus will shift upstream to a series of shortwaves diving southeast from the Upper Midwest/Great Lakes through the Northern Mid Atlantic region. Models show some varying QPF solutions with these features, but with limited moisture look for max amounts in the 0.10 to 0.25 range over north-central PA. Following a brief moderation in sfc- 850mb temps on Sunday, the aforementioned shortwaves will bring a reinforcing shot of chilly air into the area with below normal temps forecast into the middle of next week. High pressure should provide dry weather Tue-Wed with pcpn probs increasing toward the end of the week, with GFS/EC models and ensembles showing a low pressure system reaching the Great Lakes/Ohio Valley by Thursday. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... 00Z TAFS sent. Problem will go from low clouds tonight to gusty winds on Saturday. A few rain showers tonight, may mix with some snow at JST and BFD by early morning. Improving conditions for the later part of the weekend. Visibility overall not expected to be very low over the next few days, except for brief time periods in heavier rain and snow showers. Outlook... Sun...No sig wx. Mon...Mainly VFR. MVFR with rain showers possible NW. Tue-Wed...No Sig Wx. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Watson/La Corte NEAR TERM...Watson/La Corte SHORT TERM...La Corte LONG TERM...Steinbugl AVIATION...Martin is the U.S. government's official web portal to all federal, state and local government web resources and services.