The NWS has already placed Western, PA in a Tornado Watch. An organized line of storms with embedded mesovortices and bowing segments from Lake Erie through extreme eastern OH is moving east at around 40 kt into the Pittsburgh area. A tornado watch is likely to be issued for Central, Pa within the hour.
Severe storm threat with damaging wind and a few tornadoes should continue to expand eastward into western NY and central PA this afternoon. A tornado watch will likely be issued soon.