Forecasters say a severe storm system moving through B.C.’s south coast will likely usher in avalanches on the North Shore mountains this weekend. 

Ski patrollers at Cypress Mountain say the avalanche risk is the worst they’ve seen in 20 years.

The Canadian Avalanche Centre predicts a high danger risk for slides at or below the tree line starting Friday. 

The CAC advises people using the mountains to avoid avalanche terrain and stay out of the backcountry – or face being buried. 

“Intense loading by new snow and wind will make avalanches almost certain,” a message on its website read Friday.

Up to 45 centimeters of new snow is expected to hit the North Shore Friday, with winds reaching up to 70 kilometers an hour.  The weather is expected to stabilize Saturday before another storm will usher in another 20 centimeters of snow on Sunday.

“Avalanche activity has been already been observed on this layer and the potential size of avalanches is likely to increase through Friday as the storm progress,” the CAC said.

The warning comes just a day after two out-of-bounds skiers were rescued after becoming stranded on Cypress Mountain.

Spokesman North Shore Search and Rescue members had to use a long line to rappel down to save the stranded men, who had been on the icy slope for six hours.

Tim Jones said the pair is lucky to be alive.

“This incident…could have turned out to two fatalities, it was that close."