Area Forecast Discussion
Issued by NWS State College, PA

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810 FXUS61 KCTP 240655 AFDCTP Area Forecast Discussion National Weather Service State College PA 255 AM EDT WED AUG 24 2016 .SYNOPSIS... A seasonably warm and humid late-summer weather pattern will continue across Central Pennsylvania through the weekend. The most likely period for thunderstorms remains Thursday into early Friday. && .NEAR TERM /THROUGH TONIGHT/... Mainly clear skies and calm winds will favor valley fog formation through the predawn hours. The fog should dissipate by 8-9am. High pressure retreating off the Northeast coast will ensure another dry day with southerly return flow bringing warmer temperatures and gradual uptick in dewpoints/humidity levels. Forecast maximum temperatures are running about 5 degrees above normal for late August. Multi-model/high resolution ensemble blend still highlights NW PA to the west of US-219 with max POPs /20-40 percent/ in the 00-12z Thursday period. The risk for showers is coincident with surge of theta-e/warm advection and moisture flux on nose of 20-30kt WSW LLJ. Milder overnight temps in the low-mid 60s. && .SHORT TERM /THURSDAY/... Model data shows another glancing blow from passing shortwave energy/height falls to the NW of the area on Thursday as upper ridge holds firm from the Mid South up along the Atlantic coast. However, there appears to be sufficient moisture/instability with the weakening cold front/surface trough to trigger scattered to numerous thunderstorms during afternoon/evening. Consensus blend yielded max POPs over the NW 1/3 of the CWA. SPC Day 2 outlook is largely unchanged from the previous Day 3 with just a slight NWD shift in the MRGL risk across the OH Valley into far western PA. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... The front should become rather diffuse on Friday with risk of thunderstorms confined along/ahead of the boundary. The best location at this time appears to be the southeast 1/3 of the CWA and therefore painted low POPs during the day before drying things out Friday night. Another extensive upper ridge resumes control of the weather pattern into the weekend. This should translate into a seasonably warm and somewhat muggy period although not anything like the 70+ dewpoints we experienced around mid-month. The models seem to open the door for isolated airmass/terrain-induced convection by Sunday afternoon, however the odds still favor a mainly dry weekend for most locations. For next week, the guidance is suggesting a shortwave tracking to the north of PA will drag a trailing frontal boundary into PA which may become quasi-stationary Mon-Tue. This feature would provide a focus for thunderstorm activity and have generally trended POPs upward beyond Sunday. && .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
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Expect VFR conditions early this morning to give way to some areas of MVFR and local IFR conditions in fog. Morning fog will give way to another VFR day on Wednesday. Approaching front with increased moisture could bring a chance of TSRA on Thursday, mainly in the west. Outlook... Wed...Patchy AM fog possible, otherwise VFR. Thu...Generally VFR, but with Isold pm tsra impacts possible, mainly w mtns. Fri...Morning low cigs possible across the Western Mountains, otherwise VFR. Sat-Sun...No sig wx expected.
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&& .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Steinbugl NEAR TERM...Steinbugl SHORT TERM...Grumm LONG TERM...Steinbugl/Tyburski AVIATION...Jung/Gartner

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