JB Holmes and his fellow US PGA Championship contenders could face another rough and rain-interrupted day with thunderstorms and gusting winds forecast during the third round at Oakland Hills.

Holmes is due to tee off in the last pairing with Charlie Wi at 7.40pm Irish time, with the forecast issued by tournament officials at the PGA of America predicting numerous showers and thunderstorms across the region and gusting winds of 20-25 miles per hour.

Play was suspended for 85 minutes late on Thursday as the opening round came to a temporary halt due to rain and the threat of lightning.

The third round got under way under mostly sunny skies this morning with very little movement up the leaderboard from the early-starting back-markers. With the cut coming last night at eight over par, 73 golfers remain in the championship.

England's Paul Casey, though, insisted last night anyone surviving the cut had a chance of victory. Casey, seven strokes off the halfway lead, believes the severity of the par-70, 7,395-yard course and the forecast gusting winds leave the contest wide open.

And Graeme McDowell, among the early starters almost four hours into the day's play, was putting Casey's theory to the test. McDowell began well with birdies at the par-five second and the par-four sixth, which tournament officials shortened from 387 yards following the second round, with it now measuring 285 yards to the front of the green and 318 yards to the hole.

McDowell was at four over par for the week and two under for the round having played six holes.