A flood watch remains in effect for Allegheny County and other Western Pennsylvania counties along the Allegheny River, the National Weather Service said.
Last week's deep freeze caused ice formation on the river; warmer weather has started to break it up. With rain expected today, ice could move downstream and jam, causing rapid flooding, the weather service said.
The flood watch area also includes Armstrong, Clarion, Forest, Westmoreland and Venango counties. The watch is in effect until 4 p.m. Tuesday.
Rain was expected to move into the area this afternoon, with a high temperature in the low 50s, well above normal.