The Open Championship will use a two-tee start for the first time in the tournament's history on Saturday.
Tee times have been restructured after heavy storms were forecast to hit Royal Liverpool.
Play is scheduled to get underway at 9am from both the first and 10th tee, with the field split into groups of three rather than two.
A statement from the R&A said: "The Met Office's onsite forecasters believe that there is a significant risk of thunderstorms and heavy rain, which will interrupt play."
Rory McIlroy stretched his lead to four shots following a second consecutive 66 at Hoylake.
