Area Forecast Discussion
Issued by NWS State College, PA
Issued by NWS State College, PA
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800 FXUS61 KCTP 090215 AFDCTP Area Forecast Discussion National Weather Service State College PA 1015 PM EDT Sat Aug 8 2026 .WHAT HAS CHANGED... * Expect current near-severe storms to continue to weaken, but one or two may still end up producing wind damage. * Expanded mentions of fog to much of the area overnight. && .KEY MESSAGES... 1) Near-severe scattered thunderstorms over the NW will be on a gradual down/weaking trend for the rest of the night. 2) Mainly dry for Sunday, though daily chances for showers and thunderstorms return to the forecast for next week. && .DISCUSSION... KEY MESSAGE 1: Near-severe scattered thunderstorms over the NW will be on a gradual down/weaking trend for the rest of the night. Storms continue to roll in from western PA at 10 PM EDT. Some were more-potent over the last 3 hours, but have been on the down-trend as we have lost the heating of the day. Synoptic forcing is generating additional storms at this time, and a flash flood threat has begun for the places that recived heavier rain earlier iun the evening. Rain gauge in Grand Valley has over 4" this evening. If that is accurate, the radar estimates are underdoing what has fallen. Too sparse of coverage to go with a flood watch at this point. Will cover what needs to be covered with timely warnings. KEY MESSAGE 2: Mainly dry for Sunday, though daily chances for showers and thunderstorms return to the forecast for next week. Upper level flow becomes more zonal for Sunday which should result in a mainly dry day, outside of an isolated shower or storm that develops on the higher terrain of western PA. The break from the rain will be short-lived, however, as multiple shortwaves moving through will bring daily chances for showers and storms as we head into the coming week. Machine learning ensembles suggest that there will be some severe weather potential for at least a couple of days next week and SPC has much of the region outlooked in a marginal risk for Monday. There will also be some potential for flash flooding as well, and WPC has placed all of central PA in a marginal risk for both Monday and Tuesday. There is still some uncertainty regarding the severe and flash flood risks, but the details will be worked out over the coming days. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... Scattered showers and thunderstorms across NW PA will gradually track eastward over the next couple of hours before decreasing in intensity. Current shower/storm activity appears to be tracking towards BFD; however, lower confidence on whether lightning will make it that far east base on similar storms in the area. Thus, have kept the PROB30 group and narrowed down the timeframe for an hour where TSRA/SHRA will be most likely. Radar does outlines some SHRA/TSRA along and just south of the I-80 corridor; however, guidance continues to struggle these making it much further east and impacting UNV/IPT this evening. Potential still exists for low cloud and patchy fog development overnight with highest potential at BFD where SHRA/TSRA is most likely over the next couple of hours. Guidance does indicate some potential at UNV; however, 25th percentile members of the HREF ensemble outlines VFR conditions for the airfield. Thus, have kept UNV and IPT VFR throughout the TAF package, especially given relatively dry low-levels at 00Z with a light breeze possible overnight. An additional area of fog/low cloud development is likely across south-central Pennsylvania but impacts at AOO/MDT/LNS appear unlikely at this time. A slight uptick in low-level moisture at JST does warrant some mentions of MVFR-to-IFR ceilings and have highlighted this potential based on a HREF/GLAMP model guidance blend. After sunrise, fog/low clouds likely mix out quickly and lead to widespread VFR conditions through 00Z Monday. Some isolated showers will be possible; however, best chances for any precipitation mentions likely come after 00Z Monday, thus have decided to keep any SHRA mentions out of the 00Z TAF package. Outlook... Sun...Mostly dry, some isolated showers across far W PA. Mon-Thu...Scattered showers/storms. Restrictions possible. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ WHAT HAS CHANGED...Dangelo KEY MESSAGES...Dangelo/Bauco DISCUSSION...Bauco AVIATION...Beaty