Skiiers and snowboarders are being warned not to go out of bounds this weekend because of an extreme risk of avalanches — the most recent of which has killed a man near 100 Mile House.

That slide, which swept the snowmobiler down Mica Mountain on Wednesday, brought the death toll of people killed in British Columbia avalanches this winter to 19.

John Kelly, operations manager with the Canadian Avalanche Centre, told Metro Vancouver on Thursday that the storms hitting South Coast mountains have piled heavy snow on top of weaker layers.

“That is going to drive the avalanche danger right through the roof, so in the Sea-to-Sky corridor we’re calling the avalanche danger extreme,” Kelly said.

“We’re most concerned about backcountry activities … in uncontrolled areas,” he said, adding that the danger of slides can linger well past when storms have dissipated, and that’s when fatalities happen.