UPDATED: National Weather Service Issues Flash Flood Warning

UPDATED: The National Weather Service's flash flood warning has been extended to 7:30 p.m. Saturday for central Allegheny County and east central Beaver County.

"At 4:25 p.m. EDT, National Weather Service Doppler Radar showed a line of thunderstorms with repeating heavy downpours capable of producing flash flooding," the service's website states.

The storms extend from near Monaca in Beaver County to Bellevue and Franklin Park in northwest Allegheny County, NWS states.

Radar estimates more than 2 inches of rain has fallen and 1-2 inches more may fall before 6 p.m, causing flash flooding, according to the weather service.

"The hardest hit area so far appears to be Little Sewickley and Fern Hollow Creek areas in northwestern Allegheny County, north of Sewickley and Economy Borough," the National Weather Service website states.

The service cautions motorists not to drive vehicles into areas where water covers the road because the depth might be too deep for safe passage.

"Do not underestimate the power of flood water. Only a few inches of rapidly flowing water can hold car doors shut and carry away your vehicle," the NWS warns.