Apr 10, 2015 1 min read

PITTSBURGH (AP) – A flash flood watch is in effect for six Western Pennsylvania counties and forecasters say a rising Ohio River will flood parts of Pittsburgh’s North Shore Riverwalk.

The National Weather Service says as little as a half-inch of rain on saturated ground could cause creek and stream flooding Friday morning in Allegheny, Beaver, Fayette, Greene, Washington and Westmoreland counties.

Forecasters expect the Ohio River to reach 20 feet by Saturday morning, putting about a foot of water on lower areas of the river walk.

The Pittsburgh Parking Authority closed the Monongahela River Parking Wharf. It starts flooding once the river reaches 18 feet.

The river was at 17.46 feet as of 7 a.m. Friday. It’s projected to rise steadily and stay above the 18-foot flood stage mark until Sunday afternoon.