Area Forecast Discussion
Issued by NWS State College, PA

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907 FXUS61 KCTP 201439 AFDCTP Area Forecast Discussion National Weather Service State College PA 1039 AM EDT Sat Oct 20 2018 .SYNOPSIS... A couple of cold fronts will move through today, dropping temperatures and leading to lake effect showers. An accumulation of snow is expected tonight and early Sunday over the mountains. Colder than normal temperatures but mainly dry weather are expected for much of next week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Fairly quiet across central PA at mid morning. Periphery of 500 mb shear axis extending from the eastern GLAKS to upstate NY producing enough lift to support a broken line of rain showers which will parallel the PA/NY border through the early afternoon. Temps still slightly too warm to support any snowflakes mixing in during the day. Temps are quite mild across southern PA...mostly in the mid to upper 50s south central and southeast. Temps are in the mid to upper 40s central mountains and north. The wind will veer just a little to the west through the day and the clouds over the SE should break up/clear out. This will help boost the temps into the lower 60s in the far SE. By late this afternoon, the approach of a very strong and fast moving upper trough will drop the stability and increase the shear over the NW. This could allow for a few claps of thunder out of some of the stronger showers which will form across the north. The showers will be moving very quickly, and could make gusts into the 30s. The temps won`t move much at all on over the NW today, and may slide slowly downward in the afternoon. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/... The upper heights drop drastically, bottoming out in the middle of the night. By Sunday morning, The trough axis will be along the Atlantic Coast and zipping east. The cold advection will drop the 8H temps to -8C across the north on Sunday morning and going below -5C over all the area through the day. Cold air changes the rain to snow in the evening over the NW and Laurels first. SHSN continue off the lakes and upslope areas through Sunday. A Huron connection seems to set up later at night with the fetch favorable to go into the Laurels. The west- facing slopes could pick up as much as 3 inches. But, most of Somerset and Cambria counties should not get more than an inch. Gusty winds continue as well. Temps could touch 50F in the downslope flow to the SE of Blue Mtn, but will top out in the 30s in the N/W. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... Conditions will improve Sunday night into Monday. Winds go light Sunday night and we could get a widespread freeze over the SE Mon AM. But, there could be some warm advection clouds sliding over then, as well, which could keep temps up. Will just mention the poss of freeze in the HWO. A system passing to the north of the area may bring a few light rain/snow showers to the northern tier on Tuesday into Wed. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... IFR/LIFR conditions over the NW mtns and MVFR in the central mtns will improve somewhat midday before dropping again this evening. Showers will be most widespread over the northern mountains today, with a changeover from rain to snow this evening as colder air works in. Northwest winds will again become gusty during the afternoon at 15 to 20 knots. IFR impacts in snow showers for the northern mountains and Laurel Highlands tonight with MVFR settling into central areas. Breezy NW flow persists into Sunday as restrictions recede back to mainly impacting the NW mountains. .Outlook... Sun...Rain/Snow showers and associated restrictions likely north and west in the morning, with improving conditions in the afternoon. VFR elsewhere. Mon-Wed...No sig wx expected. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Dangelo NEAR TERM...Dangelo/DeVoir SHORT TERM...Dangelo LONG TERM...Ceru/Steinbugl AVIATION...DeVoir/RXR

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