Emergency Management Director Glenn Cannon said Monday that 40 mile-per-hour winds expected for much of the state will uproot trees once the ground is saturated.
Gov. Tom Corbett says gusts of up to 75 miles per hour are possible. He says 24 counties have issued emergency declarations, while 58 evacuation centers are on standby and can shelter 31,000 people. Most areas will get three to five inches of rain, and some could see six to 10 inches.
High-water surges on the Delaware River and flooding in low-lying areas are expected.
Public Utility Commission chairman Robert Powelson says Pennsylvania's nuclear power plants are remaining online.