Phil Mickelson broke par for the 50th time at Augusta National on Thursday, overcoming the whipping winds for a one-under-par 71 in the opening round at the US Masters.

Augusta National's notoriously difficult course will be even tougher to play because of a heavy rainstorm which is expected to hit the local area on Wednesday, six-time U.S. Masters champion Jack Nicklaus said on Tuesday.

US Masters week got off to a stormy start as heavy rains swept across Augusta National Golf Club on Monday with tornado warnings forcing players and spectators off the course.