Spaun shot a front-nine 40 but came home in 32, punctuated by a 64-foot putt, to break away from a pack of challengers and claim his first major.

According to Weather.com, there's a better than 50 percent chance of rain through 5:15 p.m. in Oakmont before the percentages begin to drop precipitously to less than 15 percent by 7 p.m. Play should resume on time as long as there are no other delays.

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.

A line of storms that rolled through Oakmont between the second and third rounds hardly seemed to make an impact at the U.S. Open

Play has been suspended in the final round of the U.S. Open due to heavy rain falling at Oakmont Country Club. The horn sounded at 4:01 p.m. ET Sunday — the signal for players to get off the golf course as torrential downpour ensued. The leaders have played seven holes.

Severe weather warnings suspended play before the end of Round 2 on Friday and brought delays during Saturday's Round 3. Round 4 appears destined for a similar fate.

Today's forecast calls for about a 50% chance rain throughout the morning, according to AccuWeather, with a slight break about the time the final pairings are scheduled to tee off in the afternoon. But that gives way to a 60% chance of rain starting about 5 p.m. through close to sunset.

OAKMONT, Pa.—Rain and lightning have halted the U.S. Open on its final day. Sam Burns (-2) and Adam Scott (-1) are atop a leaderboard that's suffering through a wickedly difficult Oakmont course, and the wind and rain rolling in over the course of the afternoon made play even trickier.