Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 102259 AFDCTP Area Forecast Discussion National Weather Service State College PA Issued by National Weather Service BINGHAMTON NY 559 PM EST Sun Dec 10 2017 .SYNOPSIS... A clipper system will bring snow and difficult travel to parts of central Pennsylvania early this week. A shot of arctic air will enhance lake effect snow and may produce dangerous snow squalls on Tuesday. Gusty winds along with the brutally cold air will result in wind chills below zero over the Alleghenies by Wednesday. && .NEAR TERM /THROUGH MONDAY/... Radar trends show lake-effect snow shifting orientation into southwest NY as boundary layer flow backs to the WSW ahead of next shortwave dropping into the Great Lakes. Light snow showers and flurries over the Alleghenies should taper off by this afternoon. Plan to allow the winter wx advisory expire at 3 PM as main LES shifts north of PA/NY border. Visible sat trends indicate some breaks in the stratocu clouds over southeast PA, revealing the snow that fell yesterday to the along and east of the I-81 corridor. Cut a few degrees off maxT over these snowcovered areas but gusty winds will make it feel like its in the teens to low 20s. Winds should gradually subside into tonight. A weak, moisture-starved clipper will dive south across the region tonight, accompanied by no more than scattered flurries for much of the forecast area. However, orographic enhancement could result in a light accum of less than an inch over the northwest mountains or Laurel Highlands. && .SHORT TERM /MONDAY NIGHT/... Surface ridge will briefing track across the region Monday, supplying fair weather for most of the forecast area. Next in series of clippers will approach late in the day, perhaps spreading some light snow into the northwest counties before dark. && .LONG TERM /TUESDAY THROUGH SUNDAY/... All model guidance tracks clipper north of Pa Monday night, which should keep the most substantial snow north of Pa. However, blend of latest guidance still supports a likely period of light snow across central Pa, with accums generally in the 1-3 inch range. The coldest air of the season is forecast to arrive behind this system with a shot of arctic air and more lake effect snow lasting through midweek. WPC graphics indicating about a 30 pct chance of exceeding winter storm criteria across the snowbelt of Warren County Tue into Wed AM, so will highlight this potential in the HWO for now. Tight pressure gradient will result in gusty winds to accompany the arrival of the cold air. A quick look at model data suggests wind advisory criteria is possible early Wed, as large scale subsidence and pressure fall/rise couplet moves through. Med range guidance indicates another clipper is likely to affect the area late Thursday with another potential light snowfall. After that, ECENS and GEFS both indicate upper trough will lift out, resulting in a marked warm up next weekend. Latest EC ensemble MOS guidance indicating temps returning to near or slightly above climo by next weekend. && .AVIATION /00Z MONDAY THROUGH FRIDAY/...
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Lake flow will keep snow showers over the KBFD terminal off and on through the overnight and early morning hours. Restrictions will mainly be MVFR, though brief IFR visibility restrictions (1SM to 2SM) are possible. Mainly VFR conditions are forecast elsewhere, with a scattered to broken deck between 5000 and 12000 feet. Winds will be westerly at 5 to 10 knots. Outlook... Mon...Cig reductions likely western portions. PM light snow developing, mainly northwest Pa. Mon night and Tuesday...Periods of light snow. Widespread MVFR likely, with periods of IFR and brief LIFR cigs and vsbys. Wed...Reductions poss west in sct snow showers. Otherwise VFR. Thu...Still a chance of a few snow showers.
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&& .CTP WATCHES/WARNINGS/ADVISORIES...
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None.
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&& $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM... AVIATION...

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