The National Weather Service in Pittsburgh has issued a severe thunderstorm watch for Butler County and a number of other counties across Pennsylvania, Ohio and West Virginia.

The severe thunderstorm watch, which is valid through 8 p.m. Wednesday, warns of frequent lightning, isolated hail and scattered wind gusts of up to 70 miles per hour.

Portions of Allegheny County -- including Monroeville, Plum and Bethel Park -- are under severe thunderstorm warnings until 2:15 p.m.