The first round of the U.S. Open at Merion Golf Club was suspended due to threatening weather on Thursday at 8:36 a.m. (ET).
The suspension was not a surprise as a line of strong storms was expected this morning. There is more severe weather forecast later in the day as well.
Officials hope to resume play at 12:10 p.m. The second wave of players will have their tee times delayed three hours, 34 minutes. Sunset is slated for around 8:30 p.m. Play will continue as late as possible, if a later wave of storms stays clear of the area.
Tiger Woods and his playing partners are now scheduled for 4:48 p.m. with the final group slated for 6:31 p.m. off the 11th tee.
England's Ian Poulter had birdied his first three holes - Nos. 11, 12 and 13 - to grab an early 1-stroke lead over Nicolas Colsaerts, Charl Schwartzel, Tim Clark and Charley Hoffman.
Americans Dustin Johnson and Steve Stricker were among six players tied at minus-1.
Phil Mickelson was among a group of players at even-par. The five-time U.S. Open runner-up flew back overnight from his daughters 8th grade graduation and arrived at the course about 90 minutes before his scheduled 7:11 a.m. tee time.
Mickelson bogeyed his opening hole, No. 11, but came back with a birdie on the short par-3 13th.
Cliff Kresge, who hit the opening tee shot of the 113th U.S. Open, was 4-over through six holes.