Facing a growing avalanche threat, search crews were working Thursday to rescue three stranded skiers from the Mount Seymour area. It's a sure sign that anyone heading out into the back country should be extremely careful.

By late Thursday, one had returned to safety, while the other two were expected to make it out of the back country area by the end of the day.

Over a period of 24 hour another B.C. south coast mountain -- Cypress Mountain - was blanketed by more than 20 centimetres of new snow.

"In the last two weeks, we've just had snowfall every day or every second day, and significant snowfall too," said Kent Rideout, a Cypress Mountain employee.

But there is a dark side to the winter conditions, one search and rescue workers are familiar with as they headed out to find the two skiers stranded overnight in Mount Seymour's back country.

"They're in an area where our team was trapped a couple of years ago because of avalanche hazard,'' said Ron Royston of North Shore Search and Rescue.

And the avalanche danger on British Columbia's south Coast Mountains is expected to get much worse. The Canadian Avalanche Centre is issuing a special warning for this weekend.

"We had very little snow at the beginning of the year and then a long period of cold temperatures, and those cold temperatures worked away at the snow pack, making it weaker and weaker over time," said Peter Marshall of the Canadian Avalanche Centre.

A significant storm is expected to move into the region on Boxing Day, adding more layers on top of the unstable snow pack.

"It's unusual at this time of year, and it's unusual in general on the south coast. It's more typical in the Rocky Mountains," said Marshall.

All the snow we've been getting right now could also lead to problems beyond the Christmas holidays. The Canadian Avalanche Centre says the slide danger could extend into the New Year due to weak spots buried in the snow pack.

For experienced backcountry enthusiasts, the avalanche warning may simply mean adjusting their travel plans, Royston said. The inexperienced may want to cancel their plans altogether.

With a report by CTV British Columbia's Maria Weisgarber