FXUS61 KPBZ 231151 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 751 AM EDT Sun Aug 23 2026 .WHAT HAS CHANGED... Risk for severe weather this afternoon/evening in northwest PA is lower, with no other hazardous weather anticipated through at least mid week. && .KEY MESSAGES... 1) Spotty showers with low probability thunderstorm chances possible through this evening. 2) Minimal hazards for majority of week before widespread precipitation chances return to end the week. && .DISCUSSION... KEY MESSAGE 1... Upper troughing lingering over the upper OH River valley combined with cold advection over warm Lake Erie waters is enough to produced localized, brief showers with a low probability for thunderstorms through this evening. While SBCAPE peaks around 1000 J/kg around the I-80 corridor (enough to foster deeper convection), such lackluster shear (struggling to touch 20kts) should limit enough organization/intensification to keep storms below severe thresholds. Activity generally comes to an end after sunset as subsidence and loss of heating suppresses activity. The exception is near/north of I-80 in northwest PA where an embedded shortwaves in NW could create short periods where showers (mainly) through Monday. KEY MESSAGE 2... Lingering cool advection within northwest flow results in high temperatures around 10 degrees below the daily average Monday while high pressure supports dry weather (save for a low probability shower near Lake Erie). Height rises over the surface high ensures dry weather persists Tuesday into Wednesday while elevating temperature back to near the seasonal averages. Ensembles remain firm in an upper shortwave digging through the Ohio River Valley Thursday into Friday, creating the next round of widespread shower and thunderstorm chances. Model differences in timing of upper shortwave and surface boundary movement leaves large variability in potential storm environments (ex: spread between 25th-75th percentile SBCAPE values Thursday afternoon is around 700 J/kg, a significant value). Trough passage within the summer season means this period should be monitored, but little more can be confidently said at this time. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... High confidence forecast save for CIGS toward daybreak Monday which could be VFR instead of the currently forecast MVFR. IFR CIGS across the PA and WV terminals will lift to MVFR then VFR through the morning hours. They will stay VFR the balance of the forecast when there is a 45% chance they go to MVFR after 9Z Monday. FKL and DUJ could see passing showers off of Lake Erie this morning and again this evening when the next upper air disturbance passes. If those airports are impacted MVFR VIS perhaps even IFR VIS could occur. Highest confidence of airports staying dry the entire forecast are ZZV and MGW. There is a low prob that the terminals around Pittsburgh could see shower between 2-6Z, but not enough confidence to add at this time. Wind will be from the southwest with gusts eclipsing 20 knots this afternoon at the windier terminals. Outlook... Outside of low probability rain showers near Lake Erie through Monday, building high pressure and height rises aloft favor VFR through the middle of next week. The next widespread restriction and rain chances returns near the end of the week. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ DISCUSSION...Frazier AVIATION...McMullen/Frazier