Area Forecast Discussion
Issued by NWS State College, PA

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771 FXUS61 KCTP 111824 AFDCTP Area Forecast Discussion National Weather Service State College PA 224 PM EDT Fri Jul 11 2025 .SYNOPSIS...
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* 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
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&& .NEAR TERM /UNTIL 11 PM THIS EVENING/...
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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.
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&& .SHORT TERM /11 PM THIS EVENING THROUGH 6 PM SATURDAY/...
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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).
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&& .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... Wet signal strength likely peaks Sunday into Monday which appears tied to a frontal system progressing eastward from the Great Lakes and Ohio Valley through CPA. There will be at least some potential for strong to severe thunderstorms as this system moves through, with ensembles showing moderate instability developing. Confidence is low, however, on the exact timing of any storms. There is increasing confidence in a 48hr 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. Temperatures will remain firmly in summer mode trending near to above (+5-10F) the historical average moving into 2H of July. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
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Terrain-induced SHRA/TSRA covering the Laurels this aftn, and starting to spread to other parts of the airspace over Central PA. As these storms slide off of their terrain hot-spot, they are interacting with other storms and cold pools and generating boundaries for more convection to form. The peak heating will be the peak of convection today, with a downturn in the early evening. Thus far (18Z) only one cell has made TS over central PA today, but many more should form as we get even slightly hotter. Not much should survive past 10 PM. The least likely airfields to get wet (and a reduced flight category) are MDT and LNS. BFD should be out of the woods by 22Z. All other Terminal Forecast airfields (JST/AOO/UNV/IPT) are much more likely to have deep convection swirling around and get in the vicinity. But, have held mentions of TSRA to just PROB30 at this point due to the uncertainty of when & where the cells will be from hour to hour. With stabilization, the wind goes calm. There will be some fog form, pretty much all over the airspace, but especially in the valleys and where it will have rained in the past 9-10 hrs. Some meso mdls depict a limited incursion of marine moisture/low clouds into MDT & LNS before sunrise. However, that should break up and put them back into the same boat as all other airfields for Saturday = scattered SHRA/TSRA with 30-50pct chc of rain/reduced cigs/vis at the airfield. Since most of these will be after 18Z, we haven`t mentioned them in the TAFs just yet. Outlook... Sun...Widespread SHRA/TSRA ahead of a CFRONT. Sun night-Mon...CFROPA. Widespread SHRA TSRA, mainly SE. Tue...Mainly VFR. Isold PM TSRA poss S. Wed...Sct SHRA/TSRA poss area-wide.
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&& .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Dangelo NEAR TERM...Dangelo SHORT TERM...Dangelo LONG TERM...Colbert/Bauco AVIATION...Dangelo