Jordan Spieth struggles as Royal Troon weather shows its teeth

The American teed off at 8.55 am local time and carded four early birdies to get back to level par but things then got ugly as he approached the turn with the weather deteriorating.

The wind had shifted overnight to out of the west, putting it from left to right on the inward nine.

The morning forecast was for 15 to 20 mile-per-hour winds with gusts up to 30 mph, and that may have been optimistic.

With the wind picking up, Spieth bogeyed nine and 10. He double-bogeyed 11 and then bogeyed 15. That left him at five over par, one worse than his score when the round began.

He was not alone. Danny Willett, this year's Masters champion, started in the group before Spieth and racked up four bogeys on the front nine and two more on the back. Three birdies were not enough to keep his score from ballooning to seven over.

Twice Masters champion Bubba Watson, playing alongside Willett, collected five birdies but also suffered three bogeys and a triple bogey. That took him to five over and, like compatriot Spieth, one shot worse off than his starting score.

Tournament leader American Phil Mickelson will be on 10 under par when he tees off at 3.20 pm. Playing with him will be Swede Henrik Stenson, who is one shot back. Whether they can hold onto those sort of scores could well depend on the weather.

The wind is forecast to pick up in the afternoon, and the temperature is expected to drop. The good news is that the rain is likely to hold off until early evening.