Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 162214 AFDCTP Area Forecast Discussion National Weather Service State College PA 514 PM EST Mon Jan 16 2017 .SYNOPSIS... A warm frontal system will approach the region tonight and Tuesday, followed by a cold front Tuesday night 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 TUESDAY MORNING/... Most significant radar returns early this evening are across the NW Mtns, but very dry air at low levels resulting in just virga in that part of the state based on surface obs and web cams. Further south, developing WAA resulting in scattered showers working into the Laurel Highlands at 2145Z. Near term guidance supports chance/slight chance POPs early this evening across the southern counties. Temps safely above freezing, so not anticipating icing problems in that part of the state early this evening. As the warm air advection continues into the overnight, moisture will similarly continue to increase with the chances for rain ramping up the deeper into the evening we get. The diffuse warm front will be advancing through the area tonight complicating the temperature forecast as light rain invades the region. Low temps will drop back to near or below freezing over much of central and northern Pa where a Freezing Rain Advisory has been hoisted. Southern areas will see temperatures get close and near term trends will have to be monitored for the possibility of expanding the icing forecast. QPF will be light so amounts of ice are not expected to be significant, but as we have seen several times in the past few weeks, even a little ice on untreated surfaces can cause significant problems. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... Periods of rain will continue Tuesday morning as the warm front advances north. By afternoon the cold front at the surface will be entering my western zones while the upper thermal ridge will have already progressed off to our east, leading to the rain becoming more showery as thermal advection changes sign to negative. Regardless, it`s not a terribly cold airmass upstream so Tuesday`s highs are expected to be on the mild side, averaging about 5-10 deg above normal. Over my far SWRN and NWRN zones where the warm air is expected to make a more aggressive push, highs will be some 10-20 deg above normal. I kept POPs rather high for Tuesday, but given the diffuse nature of the warm front, precipitation is likely to be intermittent and generally light in nature. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... Winds turn westerly behind the system by Wednesday morning as flow turns more zonal, but with no real cold air in sight, temps will remain on the mild side and above freezing during the day. 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 bulld of pcpn looks to be rain at this point. && .AVIATION /22Z MONDAY THROUGH SATURDAY/...
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21Z TAFS sent. Band of showers to the north, could see some precipitation aloft earlier, as I was leaving to come to work. Further to the west and south, more in the way of showers. At the current time, temperatures are above freezing, but dewpoints are low, and ground temperatures are still cold. Thus still have the potential for freezing rain, especially on untreated surfaces and cold objects. Earlier discussion below. MVFR ceilings remain over my SERN terminals a weak SSE low level flow has kept the moisture locked in over the area. Elsewhere ceilings generally above 5000` prevail as overall cloudiness continues to increase from the west. Restrictions are likely to develop/return during the evening with widespread MVFR to LIFR conditions a good bet by late evening through Tuesday as rain gradually spreads across the airspace. There will be a risk for freezing rain, mainly over the northern 1/2 of the airspace between 05-15Z Tue. Outlook... Wed...MVFR/IFR west; MVFR central to VFR southeast. Rain showers west ending Wed ngt. Thu-Fri...No sig wx. Sat...Sub-VFR developing with the approach of a warm front.
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&& .CTP WATCHES/WARNINGS/ADVISORIES... Freezing Rain Advisory from midnight tonight to 10 AM EST Tuesday for PAZ004>006-010>012-017>019-037-041-042-045-046- 049>053-058. && $$ SYNOPSIS...La Corte NEAR TERM...Fitzgerald/La Corte SHORT TERM...La Corte LONG TERM...Lambert/Gartner AVIATION...La Corte/Martin is the U.S. government's official web portal to all federal, state and local government web resources and services.