Storms and massive temperature swings across Western Canada in recent weeks are causing instability in the snowpack in the Rocky Mountains.
The dangerous conditions prompted officials to issue avalanche advisories in popular backcountry areas earlier this week.
A special avalanche warning, which is in place until Monday, now includes Banff, Yoho, Kootenay and Jasper national parks.
It extends from the southern boundaries of the Purcell Wilderness Conservancy and Kokanee and Valhalla provincial parks to Williston Lake north of Pine Pass and Mackenzie, B.C.
Avalanche Canada says “storm cycles that hit Western Canada over the past weekend added significant snow on top of an exceptionally weak lower snowpack.”
“This has brought the conditions to a tipping point where dangerous avalanches are likely.”
Avalanche Canada says making conservative terrain choices can help manage risk.
“Sticking to lower angle slopes and choosing smaller objectives that minimize the consequences of an avalanche are examples of how to reduce the risk,” it says in the warning.
Human-triggered avalanches are very likely, and Parks Canada says reports of those slides are coming in almost daily.
Parks Canada is managing some of the risk by blasting near Banff and along Highway 93 — south into B.C. — in an effort to make highways safer.
But skiers looking for fresh lines are being warned to plan ahead and avoid unnecessary risk.
READ MORE: Parks Canada responds to distress calls from backcountry skiers in Banff area
Dave Stark with Yamnuska Mountain Adventures says this year’s snowpack is unusual, and it’s not likely to change any time soon.
“This year there’s a more complicated snowpack with two to three layers that many of us are worried about,” he said.
“They’re deep layers and it’s a bit more of a concern this year because they’re going to lurk there for quite a while, I think.”
Those layers are causing the instability in the mountains and creating challenging conditions, even for seasoned skiers.
Stark says there has been a surge of interest in avalanche skills training (AST) over the past two years. He adds that such skills can mean the difference between life and death.
“People are starting to get the message out that if you want to go backcountry skiing, your minimum requirement is an AST 1 course,” he said.
“People who go into the backcountry have to understand the complexity of the snowpack, otherwise they can get caught up.”
Stark says people should always have a back-up plan and not be afraid to turn around if things don’t seem right.
–with files from Meghan Cobb, Global News, and The Canadian Press