Area Forecast Discussion
Issued by NWS State College, PA

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405 FXUS61 KCTP 180328 AFDCTP Area Forecast Discussion National Weather Service State College PA 1028 PM EST Tue Jan 17 2017 .SYNOPSIS... A warm front will lift across the region this evening followed by a cold frontal passage late tonight and early Wednesday. High pressure will follow and bring mainly dry conditions with temperatures several degrees above normal from the middle of the week into the weekend. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... The combination of cold dense air trapped in the valleys and increasing moisture associated with the approaching occlusion/warm front is causing areas of fog. The front appears to be so weak it is sliding over the low level cold air, leading to diminishing hopes that we will scour out any time soon. This suggests a rather murky start to Wednesday with low clouds gradually lifting and breaking up by late morning into the afternoon as a secondary cold front brings a stronger push of cooler-drier air/ The new airmass will not be especially chilly, barely cold enough to produce a flurry on the trough`s backside, but those will favor the usual higher elevation terminals of the west. Low temps early Wednesday will range from the mid 30s acrs the northern mountains, to the lower 40s in the south. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/... Gradual improvement is expected as the Wednesday wears on...but it will be a slow process as 5h low drops ESE to the Del Marva by afternoon...helping a secondary front drop across the area to signal improvement in the afternoon. Skies will be mostly cloudy throughout with some brightening mid to late afternoon south central and southeast. Highs will range from the upper 30s north to around 50F southeast. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... Ridge re-establishes itself over the eastern U.S. for late in the week, as mild SW flow persists over the midwest. Guidance suggests energy will dive south along the west coast eventually helping to strengthen the building upper ridge over the east. 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. Another wave approaches/lifts into the OH valley late next weekend into next Monday. Again, temps could be marginal at the start of pcpn overnight Sunday for some ice or snow, but the bulk of pcpn looks to be rain at this point. However, some guidance suggesting enough presence of cold air to for wintry p-types across northern PA. && .AVIATION /04Z WEDNESDAY THROUGH SUNDAY/... Warm front lifting very slowly across the region is being caught by the cold front as it pushes across Central PA this evening and early overnight. Thus, widespread MVFR to IFR conditions expected (with areas of dense fog possible) through much of the overnight with showery/drizzly conditions as flow not strong enough to scour things out. Pockets of -fzra remain possible across the northern airspace thru 15z but marginal surface temperatures should limit icing impact. Even KJST which is currently VFR at 02z will deteriorate behind the cold front in moist upslope flow. Gradual improvement will begin toward sunrise as flow picks up from the west. Should see improvement initially across the southern mountains and spreading into the susquehanna valley by mid morning. As always, improvement will be slowest across the west, which may not see VFR reached until Thursday. Outlook... Wed...MVFR/IFR west. MVFR to VFR central-southeast. Rain showers west ending Wed ngt. Thu...No sig wx. Fri...Sub-VFR possible with rain moving SW-NE. Sat...No sig wx. Sun...No sig wx. && .CTP WATCHES/WARNINGS/ADVISORIES... Dense Fog Advisory until 6 AM EST Wednesday for PAZ004>006- 010>012-017>019-025>028-034>037-041-042-045-046-049>053- 056>059-063>066. && $$ SYNOPSIS...La Corte NEAR TERM...La Corte SHORT TERM...DeVoir LONG TERM...Lambert/Gartner AVIATION...RXR

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