The tornado touched down around 5 p.m. Friday near Ligonier, about 50 miles southeast of Pittsburgh. The storm damaged at least three businesses and eight homes, and crews were still assessing the damage, said Sandy Smythe, a spokeswoman for Westmoreland County Department of Public Safety.
"We have no reports of injuries, which is a blessing," Smythe said.
Officials did a general survey of the damage Friday night and were planning to do a more detailed review on Saturday; officials did not have an immediate cost estimate for the damage. A shelter was set up at a nearby YMCA, but only a few people came through, Smythe said. About 6,000 residents were also still without power.
Elsewhere, the storms caused an inflatable dome at Robert Morris University, about 10 miles outside Pittsburgh, to collapse.
University spokeswoman Kyle Fisher said a microburst of high winds apparently tore the roof of the dome. About 10 people were inside at the time, Fisher said, but all escaped without injury. The dome is part of a larger sports complex that's located on an island in the middle of the Ohio River.
The dome was about 80 feet high and the size of two soccer fields, and about 12 years old, Fisher said. She said the school has not decided whether to rebuild it.
The intense weather moved eastward, bringing high winds and heavy rain. Tornado watches were in effect until 2 a.m. Saturday in parts of eastern and central Pennsylvania. Flash flood warnings were also in effect for parts of those areas.
