Storm Cycle Triggers Widespread Avalanches in Banff and Kananaskis

What’s Happening? Avalanche danger remains extremely high across Banff National Park and Kananaskis after days of heavy snow, rain, and strong winds. Officials are urging people to stay away from avalanche terrain entirely, with storm cycles now triggering slides on their own.

Why the Risk Is So High. A series of warm, wet storms has built a deep, heavy blanket of snow on top of older, weaker layers. That combination is now extremely unstable. In Banff, Parks Canada lists the danger as “High” at every elevation through at least Tuesday, with more snow and strong southwest winds continuing to load slopes.

The main issue is straightforward: new snow keeps stacking up, wind is moving it into deeper drifts, and all of that weight is sitting on top of older crusts that are failing easily. That means avalanches can be big, destructive, and triggered from a distance, or start naturally with no one around.

Even Kananaskis Safety is seeing this play out in real time. In a forecasting video recorded on December 13, a size 2 avalanche released naturally from across the valley while they were filming. A “size 2” is considered a medium avalanche, big enough to bury, injure, or kill a person, and powerful enough to snap small trees.

What Forecasters Are Seeing. Parks Canada says Sunshine Village triggered around 10 sizeable avalanches on Sunday while doing control work, most of them breaking on an older layer from mid-November. Lake Louise also brought down two large avalanches in terrain that had not yet been skied this season. On Highway 93S, steep slide paths near Mt. Wardle were visibly active.

Kananaskis teams are reporting similar conditions. New snow is sitting on top of a stiff wind-formed slab, which is failing easily in tests. Warm temperatures and extreme winds are expected to make that problem worse. Rescue crews noted a “long and loud” avalanche heard near Black Prince on Sunday, and some paths on Mt. Rundle have already run.

On-the-Ground Reports From Backcountry Users. Parks Canada reported notable avalanche activity over the weekend. In the Sunshine backcountry, control teams triggered up to 10 size 2 avalanches that broke on a weak layer from mid November. Lake Louise also brought down two size 2.5 avalanches in terrain that had not yet been skied this season, and steep chutes along Highway 93S near Mt. Wardle were observed to have cycled during the storm. In a separate Mountain Information Network report, backcountry user Michael S. noted recent slab avalanches in the backcountry Wawa Bowl area near Sunshine Village.

Impact on Travel. Parks Canada has fully closed the Icefields Parkway between Athatbasca Falls and Lake Louise until at least Wednesday, December 17 so crews can conduct avalanche control. Up to 70 centimetres of new snow is forecast for Jasper and northern Banff National Park. Officials emphasize they only close the road when conditions pose a risk to human life.

The Bottom Line. Conditions are about as touchy as they get. With natural avalanches already happening and more snow arriving, both Parks Canada and Kananaskis Public Safety are urging people to stay out of avalanche terrain and avoid any slopes with overhead hazard. Safe travel is limited to low-angle, sheltered areas well below treeline.