Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 132053 AFDCTP Area Forecast Discussion National Weather Service State College PA 353 PM EST Fri Jan 13 2017 .SYNOPSIS... An upper air disturbance will link up with a weak trough of surface low pressure nosing in from the Ohio River Valley late tonight and Saturday to bring periods of light snow to central portions of Pennsylvania and mixed precipitation or freezing rain across the south. Another area of high pressure will build east into the region for Sunday with some sunshine, seasonably cold temperatures and a light northwesterly breeze. Milder conditions will work back into the area for the middle of next week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
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Nice afternoon with more seasonable temperatures across central PA. Upstream moisture over the Ohio Valley will stream across western and central PA late this afternoon and evening... increasing mid and high clouds over central PA. A period of light mixed precipitation is the main sensible weather for late tonight and Saturday, with the main trend to suppress the northern extent of light snow to mainly areas along and south of I80. Mean QPF across the south is also more meager than earlier solutions, which may keep mean snow amounts around or slightly more than one inch. NCAR ensemble was most bullish on snow accumulations...previously indicating potential for Advisory snow amounts over the Laurels, but preponderence of guidance suggests that to be an outlier at this time. Previous advisory for the Laurels has been expanded farther east across my southern tier for snow changing to sleet and freezing rain with sub 0.1" ice amounts. Collaborated Advisory with surrounding offices. PHI may issue for our adjoining areas in time.
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&& .SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
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Snow and mixed precipitation will slowly advance eastward across central and south central PA on Saturday. Latest guidance indicates a changeover to sleet and freezing rain across my southern tier where advisories are now in effect. Farther north... little if any snowfall is expected north of I80...thanks to cold dry high pressure. Light mixed precip will taper off late Saturday afternoon across the south. Highs will be within a few degrees of freezing across the south...ranging to the upper 20s north.
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&& .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
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Light mixed precip (or very light snow) may linger for a few hours into the evening hours Saturday across southern portions of our CWA. Little if any additional snow or ice accum is expected though as precip will be light. Partial clearing or better will occur after midnight Sat with just a few flurries possible across the northern and western mtns of the state. High pressure will build into the area from the Upper Great Lakes on Sunday, supplying us with fair, chilly weather and relatively light nwrly wind. High temps will rebound by some 5-8 deg F on Sunday with respect to Saturday`s highs. At the same time, stubborn trough/upper low over the west coast weakens and lifts across the southern plains into the great lakes region as pattern. Ridge over the area tries to hold firm as a warm front lifts through Ohio River Valley early in the upcoming week. This frontal boundary will be preceded and accompanied by a light, wintry mix of precip during the morning hours Monday. A good portion of next week is shaping up to be mild and showery, as bulk of med range guidance shows a ridge slowly retreating off the East Coast as remnants of that west coast low get picked up by the northern stream and track across PA midweek. For Tue into Tue night, deep southerly flow ahead of that trough will bring a plume of anomalous PWATS over the region which supports the idea of showery (rain) and mild weather. As has been the case frequently lately, the GFS brings the trough through faster than the ECMWF. Winds turn westerly behind the system as flow turns more zonal, but with no cold air in sight, temps will remain mild and above freezing. Ridge re-establishes itself over the eastern U.S. for late week, as mild SW flow persists over the midwest. We`ll be on the eastern side of this, so subtle shortwaves sliding into the Midwest will bring varying amounts of cloudiness to the west (less in the east) with low end chances for light showers.
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&& .AVIATION /21Z FRIDAY THROUGH WEDNESDAY/... VFR conditions will prevail this afternoon into tonight with mid- high clouds lowering from south to north into Saturday. Wintry mix spreads northeast from WV after midnight. Odds favor wintry mix over the southern 1/3 to 1/2 of the airspace on Saturday but potential is there for snow/ice to expand farther to the north to the I80 corridor. Outlook... Sat...Sub-VFR likely with wintry mix southern 1/2-1/3 airspace. VFR northern 1/2. Sun...VFR/No sig wx. Mon-Tue...Sub-VFR likely with chc of freezing rain/rain. && .CLIMATE... Daily record maximum temperatures were set at Harrisburg (65), Altoona (66) and Bradford (56) yesterday 1/12/17. A daily rainfall record of 1.92 inches was also set at Bradford. && .CTP WATCHES/WARNINGS/ADVISORIES...
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Winter Weather Advisory from midnight tonight to midnight EST Saturday night FOR PAZ024-025-033>036. Winter Weather Advisory from 4 AM Saturday to midnight EST Saturday night FOR PAZ064-065.
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&& $$ Synopsis...DeVoir Near Term...DeVoir Short Term...DeVoir Long Term...RXR Aviation...DeVoir/Steinbugl Climate...

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