The National Weather Service in Pittsburgh issued a severe thunderstorm warning for northern Butler County and five other counties until 6:30 p.m. Thursday.

According to the warning, a severe thunderstorm was located 7 miles northeast of Slippery Rock, and it was estimated to be moving at about 45 mph southeast.

The weather service is warning of hazardous gusts up to 60 mph that could damage trees and power lines.

The thunderstorm warning comes after the weather service posted a hazardous weather outlook at 5 a.m. Thursday, warning of possible scattered severe storms with conditions that could possibly produce high winds, hail and tornadoes.