Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 012049 AFDCTP Area Forecast Discussion National Weather Service State College PA 349 PM EST Thu Dec 1 2016 .SYNOPSIS... A large and deep storm system will move slowly through Quebec over the next couple of days keeping a prolonged period of cool northwest flow over the local area. High pressure will build in for a brief time Sunday before the next frontal system approached early next week. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Cool west- northwest flow pattern and subsequent cold season strato- cu clouds will persist into the evening hours. Clouds will dissipate later this evening especially east of the central mountains. Near the lakes, snow showers are possible overnight but no significant accums are expected. Otherwise only a few sprinkles are expected. The wind is expected to become a bit more NWLY overnight which will help bring precipitation more into my NWRN zones. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... The cold NW flow will remain air in place for Friday, but again the cold air is unimpressive so NW snow shower activity is not expected to amount to more than nuisance amounts. With high temps expected to be above freezing, most areas will ave a hard time making any snow stick at all. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... As low continues to move further east into the Canadian Maritimes, lake effect snow showers over the NW mtns will gradually wind down on Sat. But one last shortwave Fri night could be enough to extend snow bands into parts of the central mtns for a time. Sunday brings a brief respite as high pressure moves over the state. By late Sunday into the overnight, a period of light snow is possible as a northern stream shortwave races through the region with a burst of warm advection. QPF looks to be on the order of a tenth of an inch or less, but occurring overnight many places could see their first coating of snow of the young season by Mon morning. Another ridge moves through on Monday as progressive weather pattern becomes more active. On Tues there is decent agreement in bringing the SW US upper low up through the OHIO Valley as a shearing out shortwave and diffuse surface low. Unless cold air damming traps enough chilly air in the low levels to make for some freezing rain, the precip type with this midwest system looks to be mainly rain. The end of the week brings some model disagreement with the GFS/GEFS being faster than the ECMWF with the next large upper trof and frontal system. Either way, precip looks like a good bet around the Thu/fri period as all solutions eventually bring this trough through. So predictability is increasing, but timing issues remain. Best bet for precip at this point is mainly rain over the SE as decent push of warm air lifts ahead of the system, with a rain/snow mix further north where warm air will not infiltrate as much. Behind the trough, looks like a chilly weekend in store with a potential sharp dropoff in temps. && .AVIATION /21Z THURSDAY THROUGH TUESDAY/... Through the afternoon, expect persistent MVFR CIGs over the upslope region from KBFD to KJST and possibly extending into KUNV/KAOO, and conds across the east. After a brief lull in the wind speeds this morning over Eastern Pa, expect a rather gusty daytime, as stronger flow aloft begins mixing to ground level. Bufkit soundings support frequent gusts to around 25kts across the entire region later today. A WSW wind flow should keep lake effect snow showers mainly north of the border the rest of today. However, latest model data suggests a slight shift in the wind could cause the lake effect snow showers to move from upstate NY into NW Pa tonight. Thus, IFR vis reductions appear possible at KBFD tonight. Outlook... Fri-Sat...MVFR CIGS and ocnl SHSN/IFR vis possible KBFD/KJST. Sun...Slight chance of light snow/reduced vis at night. Mon...No sig wx expected. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ Synopsis...Gartner Near Term...Gartner Short Term...La Corte/Gartner Long Term...La Corte/RXR Aviation...Gartner is the U.S. government's official web portal to all federal, state and local government web resources and services.