Avalanche Forecast
Regions: Bonnington, Crawford, Grohman, Kokanee, Kootenay Boundary, Kootenay Pass, Moyie, Norns, Rossland, St. Mary, Valhalla, Ymir.
Don't let your guard down as storm snow begins to stack up. Buried weak layers remain possible to trigger.
Avoid exposing yourself to large slopes or avalanche paths.
Confidence
Moderate
Avalanche Summary
No avalanches have been reported since Thursday. Recent human and naturally triggered avalanches have been destructive, running full path. Check out the photos below for an explosive triggered avalanche near Nelson, and a rider triggered avalanche in the Bonningtons.
On Monday we expect small slabs within the storm snow. Human triggering of deeper weak layers is still a concern and will likely produce a high consequence avalanche.
Snowpack Summary
Storm totals are expected to reach 20-40 cm by Monday afternoon, falling on a variety of weak surfaces - a crust on sun affected slopes, surface hoar in sheltered terrain, and wind affected snow in exposed areas. The bond between the old snow surface and new snow is expected to be poor.
A widespread crust with weak facets above is buried 80-150 cm deep and remains a concern for human triggering. While reports suggest this layer is becoming harder to trigger, it has produced very large avalanche activity this week.
The snowpack below the crust is generally strong.
Weather Summary
Sunday Night
Cloudy with 5 to 15 cm of snow. 30 km/h southwest ridgetop wind, gusting to 70 km/h. Freezing levels remain around 1000 m.
Monday
Cloudy with 5 cm of snow. 20-30 km/h southwest ridgetop wind. Freezing levels rise to 1500 m, with treeline temperatures around -3 °C.
Tuesday
5-15 cm of snow overnight in the Selkirks.
Cloudy with another 5-15 cm of snow for the Selkirks. 30-40 km/h southwest ridgetop wind. Freezing levels rise to 1500 m, with treeline temperatures around -3 °C.
Wednesday
Mostly clear skies. 10 km/h northwest ridgetop wind. Freezing levels rise to 1500 m, with treeline temperatures around -3 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be aware of the potential for large, destructive avalanches due to the presence of deeply buried weak layers.
- Use increased caution at all elevations. Storm snow is forming touchy slabs.
- Be careful to keep storm day fever from luring you out into bigger terrain features.
- Remote triggering is a concern, watch out for adjacent and overhead slopes.
Avalanche Problems
Persistent Slabs
Significant uncertainty exists about the likelihood of triggering this layer moving forward. Avoid areas where the snowpack thins, like steep, rocky start zones where weak layers are more easily triggered.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 2 - 3.5
Storm Slabs
Storm snow is likely not bonding well with the snow below producing small but reactive slabs. Small avalanches could step down to deeper weak layers.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1 - 2