PITTSBURGH, PENNSYLVANIA — Western Pennsylvania faces the greatest severe weather threat in the state today, Saturday, August 22, as an incoming cold front brings increasing wind shear and instability, with Pittsburgh and Erie carrying a 30 to 50 percent chance for strong to severe thunderstorms this afternoon.
Zone Breakdown Across the State
According to PA Weather Plus, the severe threat is broken into distinct zones across Pennsylvania. Zone 2, covering Pittsburgh, Erie, Meadville, Butler, and Washington, carries the highest probability at 30 to 50 percent for strong to severe thunderstorms this afternoon.
Zone 1, a transitional band running through DuBois, Clearfield, Altoona, and Somerset, carries a lower 10 to 30 percent chance for strong storms at any point Saturday. The remainder of the state, including State College, Harrisburg, Scranton, and Philadelphia, falls into Zone 0, where only non-severe thunder is expected.
Timing
Increasing wind shear and instability ahead of the cold front are expected to support thunderstorm development after 2 to 4 PM, with the majority of the severe weather action expected to occur between 4 and 8 PM.
Forecasters note that not every location within the threat zones will see a thunderstorm, and that these probabilities specifically reflect the chances for strong or severe storms, while overall shower and thunderstorm coverage will be considerably higher throughout the day.
Threats by Zone
In Zone 2, covering Pittsburgh and Erie, the greatest risk is locally damaging wind gusts of 55 to 65 mph, along with the potential for quarter-sized hail. A brief tornado cannot be ruled out in this zone…