Avalanche Forecast
Regions: Bonnington, Crawford, Grohman, Kokanee, Kootenay Boundary, Kootenay Pass, Moyie, Norns, Rossland, St. Mary, Valhalla, Ymir.
⚠️Dangerous avalanche conditions⚠️
Stick to low-angle terrain and be mindful of overhead hazard. Large human-triggered and remote-triggered avalanches remain likely.
Confidence
Moderate
Avalanche Summary
Many very large persistent slab avalanches occurred in the Selkirks on Monday and Tuesday (size 3.5), including explosive-triggered avalanches and a notable size 3.5 avalanche triggered remotely from a ridgeline in the Bonningtons. A notable incident involving a persistent slab avalanche also occurred west of Cranbrook on Sunday.
Smaller storm slab avalanches also occurred over the past few days, but the persistent slab problem should dominate terrain choices.
Snowpack Summary
Storm snow is gradually settling and a thin crust is likely forming on sun-exposed slopes. A prominent crust is found 100 to 150 cm below the surface, with several potential weak layers above it including facets, surface hoar, and thin decomposing crusts. These layers continue to produce concerning avalanches across the region. The snow below the crust is generally strong and bonded.
Weather Summary
Wednesday Night
Clear skies. 20 km/h northwest ridgetop wind. Treeline temperature -14 °C.
Thursday
Sunny. 20 km/h west ridgetop wind. Treeline temperature -5 °C.
Friday
Mix of sun and cloud. 30 km/h southwest ridgetop wind. Treeline temperature -3 °C.
Saturday
Mostly cloudy with up to 5 cm of snow in the Monashees and Selkirks and a mix of sun and cloud in the Purcells. 45 km/h south ridgetop wind. Treeline temperature -3 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Use conservative route selection. Choose simple, low-angle, well-supported terrain with no overhead hazard.
- Remote triggering is a concern, watch out for adjacent and overhead slopes.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
- Keep in mind that human triggering potential persists as natural avalanching tapers off.
Avalanche Problems
Persistent Slabs
Buried weak layers remain sensitive to human triggering and could result in very large avalanches. It is possible to trigger these layers remotely and avalanches have the potential to run full path, so watch your overhead exposure.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 2.5 - 3.5
Storm Slabs
Heavy snowfall over the past week has left storm slabs at all elevations. If triggered, these storm slabs could trigger larger persistent slab avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1.5 - 2.5