Bob Harig and Michael Collins demonstrate the tight quarters at The Open in keeping with old traditions. (1:19)

PORTRUSH, Northern Ireland -- With weather forecasts calling for heavy rain and very strong wind gusts on Sunday, the R&A has moved up the tee times by an hour for the final round of the 148th Open Championship at Royal Portrush Golf Club.

The R&A moved up the first tee times to 2:32 a.m. ET, with the leaders going off at 8:47 a.m. ET.

Players battled inclement weather earlier in the week, but the conditions for Saturday's third round were largely benign, with 30 of the 73 players in the field shooting under par.

"Weather looks pretty poor from about 9 a.m. onward [on Sunday]," said Englishman Danny Willett, who shot 6-under 65 on Saturday to move into the top 10. "Then this place will grow some teeth again. ...

"If [the weather] is what is forecast tomorrow -- 10-, 15-mph winds and raining -- this place will be a completely different kettle of fish. Just have to go to bed and wake up and see."

The forecast from the Met Office, the national weather service in Northern Ireland, on Sunday calls for "persistent and occasionally heavy rain during the afternoon and evening" with winds at 15 mph and gusts at 25 mph. There's a 40% chance of gusts as strong as 35 mph after 11 a.m. ET.

"It will be hard," said Xander Schauffele, who sits at 5-under after firing a 2-under 69 on Saturday. "If it's normal wind, the hard holes play really difficult. There's about six birdie holes, and everything else is holding on for dear life."

In the first major of the season, at the Masters in April, Augusta National Golf Club officials moved up the Sunday tee times and had players tee off on Nos. 1 and 10 in threesomes because of the threat of severe thunderstorms.