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 being completed on Sunday is now dependent on the weather and daylight cooperating at Oakmont. NBC's Mike Tirico reported that the U.S. Open could withstand a two-hour weather delay and still finish the final round on Sunday. The delay ended up lasting less than two hours indicating the final round could be completed as scheduled.