


Area Forecast Discussion
Issued by NWS State College, PA
Issued by NWS State College, PA
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-- Discussion containing changed information from previous version are highlighted. --174 FXUS61 KCTP 120226 AFDCTP Area Forecast Discussion National Weather Service State College PA 1026 PM EDT Fri Jul 11 2025 .SYNOPSIS... * Continued seasonably warm and humid with near to above normal temperatures into mid July * Daily doses of drenching thunderstorm downpours capable of producing isolated wind damage * Episodes of rain continue this weekend into early next week with the strongest wet signals on Sun-Mon * Driest, but not entirely dry, timeframe may be Tues-Wed && .NEAR TERM /UNTIL 8 AM SATURDAY MORNING/... Cu popped off the ridges and continues to be the generation point for most/all of the SHRA thus far. As more SHRA and their boundaries interact with each other, these boundaries will be additions to the purely terrain-driven convection we have early this aftn. The mixed-layer CAPE is increasing per latest mesoscale analysis trends. So, the SHRA should turn into TSRA as we warm even just a couple of degs F this aftn. Highest PoPs are placed in the central mtns for the aftn and early evening as the current mass of SHRA and associated meager forcing slides eastward a little. Evening time should bring stabilization, but not sudden. Some SHRA/TSRA may linger close to midnight. The bigger threat with any of the tallest TSRA will be heavy rain out of something slow-moving/drifting. But, an isold gust into the 50s is not totally out of the question. && .SHORT TERM /8 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... More muggy conditions are in store tonight. As the SHRA/TSRA go away, some fog is expected to form, mainly in the valleys. With fog being so random this morning, we can`t argue against including it for any/all of the CWA. Min temps will generally match the morning dewpoints: M60s-L70s. Expect the fog to burn off by 13Z. That should result in another day with weak forcing and mainly pulse SHRA/TSRA in the aftn and evening. They should, like Friday`s convection, be terrain-induced at first and drift away as they mature into the meager shear profile (<20kts). The risk for severe gusts/hail remains low (general thunder from SPC), and the risk for flooding may be only a little higher but still only in the marginal category factoring in the lower shear (vs Fri) and slower cell movement, and the slightly lower PWAT values (1.5" vs 1.75" Fri). && .LONG TERM /SUNDAY THROUGH FRIDAY/... Unsettled pattern continues through the weekend and into the beginning stages of next week with highest signal for precipitation on Sunday with a cold frontal passage across the region. Ample instability, shear, and moisture will bring about some potential for severe thunderstorms along and ahead of the front; however, model timing differences do continue into this forecast cycle, which could limit severe potential. Heavy rainfall is also expected with these storms, with PWATs approaching 2.00" during the afternoon/evening hours. Best moisture at this point seems focused over eastern Pennsylvania, where highest month-to-date rainfall totals have been observed; however, a couple of days (relatively) dry conditions could allow for some relief before the next batch of heavy rainfall. Confidence continues to increase in much of central Pennsylvania getting an extended break in the rainy summer pattern next Tuesday and Wednesday. This "dry" signal is reflected in the latest medium range models and ensemble guidance which shows sfc high pressure/upper level ridge moving into the area in the wake of the aforementioned frontal system. There does remain some uncertainty on eastern extent of the frontal system with some potential for the front to get hung up across southeastern Pennsylvania throughout this period, which will keep SChc PoPs in this timeframe. Unsettled pattern returns for all of central Pennsylvania with increasing humidity and heat allowing for a return to the typical summer-time pattern that has been observed recently. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...-- Changed Discussion --Lingering showers have all but dissipated across central PA as of 02z. As the clouds dissipate and/or peal away from the area, fog formation is visibile on the nighttime microphysics imagery across the northern valleys...espeially in areas that received earlier rainfall. Expect additional fog formation overnight with diminishing winds and plentiful low-level moisture. A marine layer and associated low clouds were also observed drifting westward towards southeastern PA at 02z, and will have to monitor this trend through the overnight hours as this could impact the Lower Susq Valley (MDT/LNS). With fog already forming in the northern valleys, and seeing BFD`s vsby dip to 6SM, have hit the BFD TAF a bit harder with fog than the LAMP model guidance. A possible fly in the ointment for additional fog formation across NW PA could be cloud debris drifting into the area from convection north of Lake Erie. This will bare watching overnight as well. Any fog/low clouds should dissipate Saturday morning, giving way to at least partial sunshine. Scattered showers/storms could once again develop in the warm, muggy airmass on Saturday. This has not been noted in the TAFs yet, so mentioning the possibility here in the AFD. Outlook... Sun...Numerous SHRA/TSRA developing ahead of a CFRONT. Sun night-Mon...CFROPA; Widespread SHRA/TSRA, mainly southeast. Tue-Wed...Mainly VFR. Isold PM TSRA poss, mainly south.-- End Changed Discussion --&& .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Dangelo NEAR TERM...Bauco SHORT TERM...Dangelo/Bauco LONG TERM...Bauco/NPB AVIATION...Evanego