The National Weather Service Pittsburgh issued a severe thunderstorm warning for a region that includes northern Butler County that is in effect until 5:15 p.m. Thursday.

Additionally, there is a severe thunderstorm watch in effect for western Pennsylvania, eastern Ohio and the northern panhandle of West Virginia that is in effect until 9 p.m. tonight.

According to a Twitter post from the weather service, more than 9 million people in the affected region could see “a couple tornadoes,” hail the size of ping pong balls and winds up to 70 miles per hour.

According to the warning post for northern Butler County, winds could reach up to 60 miles per hour and bring with it hail the size of ping pong balls.