FXUS61 KPBZ 221649 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 1249 PM EDT Sat Aug 22 2026 .WHAT HAS CHANGED... No major changes have been made to the forecast overall. There is still decent confidence in the timing and scope of thunderstorm activity this afternoon and evening. Still, there risk for heavy rain/flooding has increased slightly, mainly north of I-80. && .KEY MESSAGES... 1) Increasing coverage of showers and thunderstorms this afternoon may lead to scattered instances of damaging wind gusts, with hail being a secondary threat. 2) A marginal risk for damaging wind Sunday is tied to afternoon and evening convection near the I-80 corridor. 3) Outside of lingering showers Monday near Lake Erie, dry weather favored through mid next week. && .DISCUSSION... KEY MESSAGE 1... Plenty of sunshine across the Upper Ohio Valley is allowing destabilization to take place ahead of a MCV tracking across southern Ohio. This will provide the support for lift along with an advancing prefrontal trough. By 18Z, MLCAPE increases into the 1000-1500 J/kg range at least according to RAP/REFS. This buoyancy will allow convection to increase in coverage during the early to middle afternoon hours. CAMs continue to support these ideas, with the stronger convection moving east of the region by 02Z-03Z, with a few lingering showers crossing with the main surface cold front shortly thereafter. The main severe risk remains damaging gusts. DCAPE is still pegged to remain in the 600-800 J/kg range and thus be marginally favorable for downbursts, and the best 0-6km/effective shear remains further down the Ohio Valley. So, we are likely not looking at a higher-end threat. Still, with initial discrete storms likely to conglomerate over time in multicell clusters/short lines, enough cold pool consolidation may occur to create some scattered instances of 55-65 MPH wind gusts given the healthy MLCAPE expectations. Large hail would be a secondary threat given the relatively weak shear and mid- level lapse rates, but may be possible in the strongest storms. Downpours/locally heavy rainfall totals remain possible as well, but the HREF suggests the greatest QPF potential lies just to our north and west closer to Lake Erie, and much of the I-80 corridor has higher flash flood guidance values than to the south. Precipitable water values are not excessively high (75-85th percentile) as well. Will continue to monitor, but will hold off on a Flood Watch for now. KEY MESSAGE 2... Mid-level troughing and cold advection lingers over the region on Sunday, which may support isolated/scattered shower and thunderstorms development during the peak heating hours of Sunday, mainly north of I-70. Although decreasing overall moisture depth should keep a cap on coverage, one or two strong to severe storms may be possible given the cooling temperatures aloft, if around 1000 J/kg of surface-based CAPE can develop as hi-res models suggest. KEY MESSAGE 3... Showers may linger north of I-80 and along the ridges (a cool- season type of setup) into Monday morning with ongoing cool northwest flow over a warm Lake Erie. Otherwise, high pressure and height rises aloft point to a prolonged (relatively speaking, in relation to the previous month) dry period to start next week. High temperature does start below seasonal averages on Monday before rising back near average by mid week. Long range ensembles currently favor Thursday as the next day with showers/thunderstorms as the next upper trough crosses. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... High confidence forecast showers and storms impacting airports. The best time window appears 21Z-01Z. It will be a few hours earlier for ZZV. VFR prevails until widespread showers and thunderstorms developthis afternoon and evening ahead of an advancing pre- frontal trough (1st) and cold front (2nd) combo. The strong storms could drop visibilities to IFR levels while also posing a risk for creating wind gusts to at least 30kts, potentially higher. Based on the latest high resolution models, the time window is 18-22Z in Ohio, 21-01Z PA and WV save for DUJ where it is until 2Z. Lingering shower and low probability thunderstorms eventually clear east by 06z, but cool advection plus residual moisture favors MVFR/IFR stratus development thereafter. Current probs have lowered to a 20-30% of IFR CIGS over PA and WV. The highest confidence now is our historically more frequent terminals of FKL and DUJ. Have enough confidence to add IFR CIGS at DUJ over night, but no where else, so kept them at MVFR. The eastern terminals of LBE, MGW, and DUJ may keep stratocu most of the morning, which will be teetering on MVFR/VFR threshold, otherwise CAVU. Any shower or storm Sunday will hold off until after 18Z. The highest prob of a shower or storm will be along and north of I80 in PA Sunday afternoon. Outlook... Precipitation chances linger in northwest PA into Monday before high pressure provides areawide VFR dry weather by Tuesday. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ DISCUSSION...CL AVIATION...McMullen/Frazier