VANCOUVER – Winter Olympics organisers were sweating over deteriorating weather and the host nation's homeground gold medal jinx, just 24 hours out from the start of the multi-billion dollar February 12-28 Games.

After a month of warm temperatures, which decimated snow stocks, officials were now looking at an opening weekend plagued by heavy rain and dense fog.

Despite the worries, John Furlong, the chief executive of organising committee VANOC, said on Thursday the Games, which have cost in the region of two billion US dollars, will be an occasion for all Canadians.

"We have a lot of tension in our stomachs just like you'd have before a big game," said Furlong. "Vancouver has a smile on its face. We have all worked so hard to get to where we are today."

But the mixed-bag of weather was causing frowns rather than smiles.

High up at Whistler Mountain, which will host the blue-riband skiing events, snow and poor visibility forced the cancellation of women's downhill training after just two skiers had left the starting gate.

One of those was America's Stacey Cook who crashed heavily into the side netting at speed before being airlifted to hospital.

The second training run of the men's downhill was completed with Austrian Michael Walchhofer topping the charts in a run which was brought forward because of low-lying cloud and snow.

Meanwhile, the problems at Cypress Mountain on the edge of the city, which will host the freestyle and snowboard events, piled up.

After a lack of snow meant helicopters and lorries had ferried in snow from the higher ground in a round-the-clock operation, the site was confronted by torrential rain and thick fog.

If the fog continues, it is possible that Saturday's women's moguls competition could be cancelled or delayed.

"The rain started last night and it hasn't stopped," Cypress venue manager Stephen Bourdeau told AFP.

"The weather men have indicated that the rain could keep falling into Friday night and Saturday and there is a 30-50 percent chance that it will rain during Saturday."

Fog is also causing problems.

"If there is a band of fog and we cannot see, then we cannot start the competition," said Joe Fitzgerald, director of freestyle competition with the International Skiing Federation.

Organisers insisted that there was room in the competition schedule to cater for delays.

"There are no plans to cancel or delay events on the first full day," said Cathy Priestner-Allinger, vice-president for sports services with VANOC.

"We are being prudent. We based our planning on the anticipation of delays."

Canada chef de mission Nathalie Lambert said the team would likely benefit from home advantage but denied the country was desperate to win their first gold at home after failing in Calgary (1988 Winter Olympics) and Montreal (1976 Summer Olympics).

"We know we're going to get gold medals, it's just a question of when," she said.

Meanwhile, Olympic chiefs announced that a female Russian ice hockey player had been reprimanded for an anti-doping rule violation - the first breach at the Games.

Svetlana Terenteva tested positive for tuaminoheptane after a pre-competition urine test. Tuaminoheptane is a prohibited substance "in competition" but not "out of competition."