U.S. 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.

For the first time in 11 years, opening practice at the Masters was suspended and the merchandise shop can expect a run on umbrellas with more rain forecast for later in the week.

Mother Nature is expected to throw a little bit of everything at the year's first major.

Monday's rain will be followed by hot, humid conditions on Tuesday with more thunderstorms on Wednesday, while high winds and cool temperatures, which could dip close to freezing, are forecast for the opening two rounds of the tournament on Thursday and Friday.

"I wasn't planning on doing really anything today," said American Rickie Fowler, the world's eighth-ranked player. "Mondays for me at a normal tournament are typically rest days. So this has just kind of been rest, recover and get ready for the week."

The only major held at the same venue every year, experience counts at Augusta National where the learning curve, particularly through Amen Corner, on a gusty afternoon can be cruel to the extreme.

Whether in the opening round or final round, a Green Jacket can be won or lost through holes 11, 12 and 13 as Jordan Spieth learned last year when he carded a seven at the par three 12th.

"It's a really good stretch of golf, especially with the way the forecast is looking for Thursday and Friday, the winds look like they're going to be pretty gnarly," said U.S. PGA champion Jimmy Walker.

"That's a section of the course that gets really tough, especially if the wind swirls. I think if you get through there at even par, you're doing really well.

"Everybody thinks 13 is such a cake walk. It's really not.

"It's kind of one of those trick holes. You think you should birdie it every time and then you walk away with a five."

Briton Tommy Fleetwood was among those able to squeeze in a few holes before play was halted but it was enough to learn that Augusta National is not your average championship layout.

"We play a lot of courses where it's kind of simple to wander around and go, 'Well, you can't hit it there or over there is a good miss and that will be fine'," said the Masters rookie.

"Sometimes it only takes one practice round but this place is very, very different.

"The course can work in your favour as much as it can harm you."