Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 250847 AFDCTP Area Forecast Discussion National Weather Service State College PA 447 AM EDT THU AUG 25 2016 .SYNOPSIS...
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A seasonally warm and humid late-summer weather pattern will continue across Central Pennsylvania into next week. Scattered thunderstorms with strong wind gusts are possible in the Northwest Alleghenies later this afternoon into the evening.
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&& .NEAR TERM /THROUGH TONIGHT/...
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Line of showers associated with pre-frontal trough will move across the Alleghenies early this morning before weakening to the east of RT 219/I-99. Followed the recently upgraded HRRR very closely through late morning which seemed to have a good handle on the current/evolving radar trends. Used a blend of convective- allowing models (CAMs) for the remainder of the near term period which resulted in max POPs over the NW Alleghenies during the late afternoon into early evening. This area is included in the MRGL severe Tstom risk outlook from SPC. In the absence of large-scale forcing for synoptic lift/neutral- to-weak height rises, diurnal heating - which may be delayed due to cloud cover early in the day - and small scale shortwave impulses will play a key role in renewed convective development. This of course adds some degree of uncertainty into the forecast. Assuming this occurs as is generally depicted by a consensus of CAM guidance, a few strong to locally damaging wind gusts will be possible mainly over Northwest PA within corridor of high PW and 30-40kt mid-level flow. Expect any storms to weaken after dark given loss of instability, with decreasing coverage into the overnight hours.
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&& .SHORT TERM /FRIDAY/...
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The high pressure over the southeast will weaken the trough moving through and it will become very diffuse on Friday as it slips south toward the Mason Dixon line. Temperatures and humidity will be on the rise with 90F heat likely returning to the Lower Susquehanna Valley by Friday and through the weekend.
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&& .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
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A drier air mass will reside over the area through most of Sunday. The deep-layer ridge will gradually slide off the Mid Atlantic coast this period, which allows another frontal boundary to sink southward from the Lower Lakes and become quasi-stationary over PA early next week. This will favor unsettled conditions Mon- Tue with POPs trending upward following a mainly dry weekend. Temps will remain above normal by late August standards.
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&& .AVIATION /08Z THURSDAY THROUGH MONDAY/... Line of showers/storms over eastern OH should gradually weaken as it shifts ewd across the western-central airspace between 09-12z. Confidence is low in the band holding together into ZNY sector. Agree with guidance bringing a short period of low MVFR to IFR cigs into KBFD/KJST behind the line given moist low level flow ascending the higher terrain. Conditions trend to VFR into mid-day with focus shifting to potential thunderstorm impacts for the afternoon/evening. Will wait to examine the latest CAM guidance before adding mention of thunder with the 25/12z scheduled TAFs. Scattered showers remain possible tonight with some restrictions likely heading into Friday morning. Outlook... Fri...A.M. restrictions possible; becoming VFR. Isold thunderstorms possible southern 1/4 airspace in the afternoon. Sat...Patchy A.M. fog. Otherwise no sig wx expected. Sun...Isold thunderstorms possible western 1/3 airspace in the afternoon. Mon...Isold-sct thunderstorms possible. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Steinbugl NEAR TERM...Fitzgerald/Steinbugl SHORT TERM...Dangelo/DeVoir LONG TERM...Ceru/Steinbugl AVIATION...Steinbugl

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