There's a 50 percent chance of storms from 3 p.m. to 6 p.m. ET on Sunday, according to WTAE in Pittsburgh, and radar predictions indicate that the heaviest rain will fall around 4 p.m. The showers will likely be spotty, though, with intermittent sunshine between.

The U.S. Open final round was halted at 4:05 p.m. after torrential rain soaked Oakmont, leaving standing water on the greens and in fairways.