Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 180019 AFDCTP Area Forecast Discussion National Weather Service State College PA 819 PM EDT Sun Mar 17 2024 .SYNOPSIS... A trend toward much below normal temperatures for mid to late March started today and the cold air will stick around for much of the workweek ahead. This colder air will be accompanied by gusty West-Northwest winds and several bouts of snow showers, especially over the Alleghenies and Laurel Highlands where a few to several inches of total snow accumulation is expected by Wednesday morning. Temperatures will moderate to near normal by next weekend. && .NEAR TERM /UNTIL 7 AM MONDAY MORNING/...
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Regional radar loop at 00Z shows a dwindling band of snow showers along a secondary cold front, which lies just north of I-80. Low level thte fields indicate the front will push through the southeast part of the forecast area late this evening. However, dry air and lack of large scale forcing should cause any lingering snow showers associated with it to fall apart after sunset. The focus for the rest of the night will be over the NW Mtns, where falling heights ahead of an approaching upper trough will likely support additional snow showers late tonight. Inversion heights will remain fairly low, so anticipate only minor accumulations of up to an inch over Warren/Mckean counties. Cold advection behind the front should result in steadily falling temps overnight, with min temps by dawn ranging from the mid 20s over the NW Mtns, to the mid 30s across the Lower Susq Valley.
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&& .SHORT TERM /7 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
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The upstream mid/upper level trough will drift over the region late Monday, resulting in a chilly and unsettled Monday. The combination of falling heights and diurnal heating is progged to result in steep lower tropospheric lapse rates and even a bit of cape by afternoon, resulting in scattered snow showers and even a few heavier squalls over the northwest counties. Latest CAMS indicate mainly cellular convection, due to lack of significant shear or a strong front to focus convection. Progged surface wet bulb temps indicate air temps could fall several degrees below freezing during any squalls over the Allegheny Plateau, so can`t rule out locally hazardous travel in this area during the PM hours. See no reason to deviate from NBM max temps Monday, which range from the mid 30s over the higher terrain of the Alleghenies, to the mid 40s over the Lower Susq Valley. Large scale subsidence behind the trough should cause any snow showers to end over the eastern half of the forecast area. However, a cold west-northwest flow should generate lingering lake-enhanced, orographic snow showers over the Allegheny Plateau. Relatively low inversion heights should keep additional accumuations light (generally less than 1 inch based on model qpf).
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&& .LONG TERM /TUESDAY THROUGH SUNDAY/...
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-Winter feel through the first full day of Spring -Longest stretch of below average temps since mid-January The first official week of Spring 2024 will begin on the cold side with frequent snow showers downwind of Lake Erie and over the Allegheny Plateau. There will also be the potential for localized snow squalls through midweek along with late season lake enhanced and orographic snow accumulation in the favored snowbelts and higher terrain. Several reinforcing shots of cold air will maintain one of the longest stretches (3-5 days) of below climo temperatures since mid-January, with chilly temperatures hanging in through the week. Latest guidance suggests one last cold shot Thursday, potentially setting the stage for synoptic wintry mix Thursday night into Fri morning ahead of the next weather maker. Still several days out, so there is high uncertainty with the potential system at the end of the week, and whether warmer air will make a return for next weekend.
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&& .AVIATION /00Z MONDAY THROUGH FRIDAY/... Low-end VFR to ocnl high end MVFR cigs are expected for the Northern and Western Mountains for the rest of this afternoon and evening with ocnl -SHRA (mixed with or falling as -SHRA in the valleys), while VFR category sct- bkn clouds will be found across the Central and SE part of the PA. Borderline VFR/MVFR cigs could spill into the Central Mtns (AOO, UNV, IPT) during the late afternoon/evening hours as cooling aloft occurs with the approach of a few upper level disturbances. The Lower Susq Valley (MDT, LNS) should remain VFR right through tonight and Monday. West-Northwesterly wind will frequently gust between 20 and 25 MPH late this afternoon/early this evening, before subsiding by 5-10 mph overnight then picking back up to similar speeds and gusts that we experienced today. Outlook... Monday-Thurs...Periodic snow showers and reductions, primarily across the higher terrain of Northern and Western PA. This will be enhanced by reinforcing shots of unseasonably cold air and gusty W/NW winds. West to Northwest wind gusts could peak in the 35 to 40 mph range on Wednesday. && .CLIMATE... Astronomical Spring (vernal equinox) begins on Tuesday March 19 at 11:06 PM EDT. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Lambert NEAR TERM...Fitzgerald SHORT TERM...Lambert/Fitzgerald LONG TERM...Steinbugl/RXR AVIATION...Lambert/DeVoir/Bowen CLIMATE...Steinbugl

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