FXUS61 KPBZ 051744 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 144 PM EDT Wed Aug 5 2026 .WHAT HAS CHANGED... Regional outlook remains unchanged with the moist airmass lingering into next week to offer daily storm chances with varying degrees of hazardous weather risks. && .KEY MESSAGES... 1) Diurnal pop-up thunderstorms favoring eastern OH to northwest PA have limited severe and flooding risks. 2) An active pattern continues, potentially into the start of next week, with high degrees of uncertainty in hazardous weather risks. && .DISCUSSION... KEY MESSAGE 1... Significant moisture advection with a lifting low out of the Carolinas (ahead of the western Great Lakes trough) has raised dewpoints near 70 while pumping PWAT values from 0.91 (~25th percentile) on the 00z sounding last night to 1.85 (~95th percentile) inches on the 12z sounding this morning. This moist airmass combined with diurnal heating will foster scattered showers and thunderstorms this afternoon that wane after sunset tonight. Flash flooding is the main hazard to monitor as high PWAT, warm-cloud rain process and weak forward motion can result in localized maxima that exceed 1-2" in a short period of time. However, weak shear limiting storm duration and weak forcing liming storm coverage should play a large enough role to prevent totals from reaching FFG (unless storms form over urban or poor-drainage areas) and keep any such occurrences very localized. Additionally, that lack of shear and forcing should prevent deep storm cores from tapping into drier air above 20kft to produce downburst wind potential; again, it could occur but likelihood is low and would be very localized. KEY MESSAGE 2... The general storm environment outlook for today is likely to hold into early next week: moist airmass plus weak shear resulting in diurnally-driven thunderstorms that may have spottier coverage and limited damaging wind/flood risks. This is due to the slow progression of an upper shortwave through the Ohio River Valley that does little to change the entrenched warm, moist airmass. Due to weak flow, the assessment of "favored areas" and "hazard risks" is likely to remain more of a day-off duty as prior day's convective evolution within and upstream of the region plays a larger role in that day's outlook. Additionally, better modeling of small-scale embedded waves within the weak, broad eastern CONUS troughing in the day 1-2 range may capture subtle features that could enhance thunderstorm coverage and hazard risks for a given day or even squelch such occurrences. The most that can be said at this time, then, is individuals should be aware that each day could see afternoon/evening thunderstorms worth monitoring for potential damaging wind and/or flood risks, both which should be clearer the morning of. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... Scattered showers and thunderstorms are expected this afternoon and evening, with convection already initiating across eastern OH to start the 18z TAF cycle. Given the scattered coverage, maintained PROB30s for impacts at area terminals through 00z, after which convection should begin to wane with the loss of daytime heating. A few showers may linger overnight, so also maintained VCSH to reflect that potential. Outside of storms, VFR conditions and light winds prevail. Outlook... Daily shower and thunderstorm chances expected through Sunday, especially during afternoon and evening hours, as a series of disturbances cross the Upper Ohio Valley. There is also a potential for patchy fog and stratus with low level moisture in place during early morning hours each day, especially in areas that see rainfall the evening prior. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ DISCUSSION...Frazier AVIATION...Cermak