Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 270630 AFDCTP Area Forecast Discussion National Weather Service State College PA 230 AM EDT Thu Oct 27 2016 .SYNOPSIS... An approaching weather system will bring a cold rain later tonight into Thursday with a wet snow accumulation possible from the Northern Alleghenies into the Poconos. Chilly air will hold its ground through the end of the work week with some moderation in temperatures expected for Saturday before a cool down again on Sunday with overcast skies and a chance of showers. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... Strong wind fields noted in the VAD wind display. The strong warm advection has resulted in a band of rain and snow across north central PA as of late evening. So far web cams show a light coating, will continue to monitor. Area of snow in line with the snow grids. Earlier discussion below. Broken precip shield entering my northwest counties now...generally trace amounts having been reported but a recent hourly amount of .04" over Crawford County...and this enhancement is now over Forest County. HRRR in good agreement with regional radar mosaic on precip arrival...starting as a cold rain but then transitioning to a mix with snow and maybe ice pellets...mainly after 03z along the NY/PA border (McKean and Potter Counties). Should see a fairly quick mix for generally the northern third of the state late tonight and overnight. Any snow accumulations still expected to be light with surface temperatures a couple degrees above freezing and precipitation rates slow enough to prevent significant accumulations...but an inch or so of snow accumulation closest to nys border is likely. Snowprobs indicate 2" amounts possible over the higher terrain of McKean/Potter/Tioga and Sullivan Counties. Precipitation will spread across rest of CWA overnight. South of I-80 temperatures will be warm enough to remain all rain but it will be close around I-80 where some mixing is possible for a time. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/... Milder air will change any wintry precip to plain rain early on Thursday for the northern tier. Elsewhere look for a cold rain in the morning with precipitation decreasing west to east in the early afternoon. Temperatures will not rise much with most locations seeing highs in the 40s. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... Downstream blocking should allow northern stream energy to phase with the lead trough and eventually result in a negatively tilted trough over the Northeast U.S. by Friday morning. Models show the formation of a triple point low deepening along the coast into the Canadian Maritimes by Saturday morning. A brisk northwest flow may afford some lake enhancement to shower activity Thursday night and temps are cold enough to mention rain/snow showers especially in the orographically favored areas downwind of Lake Erie. Overall the trend should be toward drier conditions into Friday. The wind gusts may end up being a little stronger than forecast on the backside of the intensifying low. High pressure briefly returns later Friday afternoon/evening before shifting southeast Friday night into Saturday morning as low pressure tracks across the Upper Great Lakes. Models and ensembles generally agree in bringing a weakening cold front through the area on Saturday and stalling it out near the PA/MD border. POPs are in the chance range mainly over the NW 1/2 with little in the way of moisture/QPF. The EC/GFS seem to be trending toward the idea of a wave of low pressure developing to the west along the wavy boundary and possibly bringing a better chance for appreciable rainfall /0.25-0.50 inch/ to southern PA on Sunday. Beyond Sunday, high pressure dominates the pattern favoring dry weather. A noticeable rebound in temperatures appears likely on Saturday with an ensemble blend yielding highs 10-15 degrees warmer than Friday. Temperatures may fall back on Sunday before moderating again into early next week as southerly flow develops ahead of low pressure in the Upper Midwest. && .AVIATION /06Z THURSDAY THROUGH MONDAY/...
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Widespread VFR conditions noted at 06Z across Central Pa. However, expect deteriorating conditions early this morning, as rain overspreads the area ahead of approaching low pressure. Model soundings, as well as latest SREF output, suggest IFR conditions are likely at KBFD after 10Z and possible between 12Z-16Z at KAOO/KUNV/KIPT. Predominantly MVFR cigs expected across most of Central Pa during the daylight hours. However, an upsloping flow is likely to yield lower (IFR) cigs at KBFD. At KJST, models indicate arrival of sfc warm front and drier sw flow is likely to bring predominantly VFR conditions for much of the day. A core of strong winds aloft will lead to marginal LLWS conditions across parts of Central/Northern Pa today. Will also have to watch for the possibility of a PM thunderstorm accompanying the trailing cold front during late afternoon/early evening. For much of the area, expect improving conditions behind the cold front, as a drier northwest flow arrives tonight. However, residual low level moisture ascending the Allegheny Mtns will likely result in persistent MVFR cigs at KBFD/KJST through Friday morning. Outlook... Fri...AM low cigs possible W Mtns. Sat...No sig wx expected. Sun...Showers/low cigs possible, esp N and W. Mon...No sig wx expected.
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&& .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Ross NEAR TERM...Ross/DeVoir/Martin SHORT TERM...Ross LONG TERM...Gartner/Steinbugl AVIATION...Fitzgerald is the U.S. government's official web portal to all federal, state and local government web resources and services.