Storm triggers flash floods in Pittsburgh; 3 inches of rain expected by day's end

Slow-moving thunderstorms are predicted to drop up to 3 inches of rain and trigger potential flash flooding in parts of several Southwestern Pennsylvania counties, a National Weather Service meteorologist said Tuesday.

By 11:30 a.m., first responders were reporting flooding on Allegheny River Boulevard in Pittsburgh; Freeport Road near UPMC St. Margaret hospital; and parts of Mifflin Road, which connects Pittsburgh’s New Homestead and Lincoln Place neighborhoods.

The section of Freeport Road, which straddles the border between Pittsburgh and Aspinwall, was “under several feet of water” before noon, dispatchers said.

Though part of that road is in Pittsburgh, Aspinwall Fire Department is handling the emergency response there, Pittsburgh public safety spokeswoman Eliza Durham told TribLive.

The storm dropped more than an inch of rain in some areas within a 30- to 45-minute span Tuesday morning, said meteorologist Jason Frazier, who works in the National Weather Service’s Moon station.

“Moderate to heavy rain” was expected to peak between noon and 1 p.m. and end around 5 p.m., Frazier said, adding that up to 3 inches of rain could hit parts of Apollo and Vandergrift. The storm will leave Western Pennsylvania altogether by around 7 p.m. tonight.

Flash-flood warnings are in effect through 1:45 p.m. in Pittsburgh and until 2:15 p.m. in eastern Allegheny County and parts of Westmoreland, Armstrong and Indiana counties, Frazier said.

Public safety officials in Aspinwall did not respond Tuesday morning to calls or emails seeking comment.