Avalanche Forecast
Regions: Bonnington, Crawford, Grohman, Kokanee, Kootenay Boundary, Kootenay Pass, Moyie, Norns, Retallack, Rossland, South Okanagan, St. Mary, Valhalla, Ymir.
6:30 AM Update: New snow and wind may form wind slabs. Use caution in lee terrain features.
Confidence
High
Avalanche Summary
A few small loose wet avalanches were naturally triggered on steep slopes Thursday. No recent persistent slab avalanche activity has been reported in the last week. If you go out in the backcountry, please consider sharing your observations on the Mountain Information Network (MIN).
Snowpack Summary
In sheltered locations at higher elevations, 10-20 cm of settled snow overlies a surface hoar layer. Surface snow is moist from 1900 m and below where a breakable crust is present near the surface. A prominent rain crust is found 40 to 70 cm deep, which is strong enough to cap another preserved layer of surface hoar found in most areas. Professionals are reporting that this weak layer is either decomposing or gaining strength, as there have not been significant results on this layer during tests recently. Typical snowpack depths at treeline are 70 to 110 cm, and taper rapidly below treeline.
Weather Summary
Friday Night
Cloudy with 5 to 15 cm of snow, alpine wind northwest 40 to 60 km/h, treeline temperature -6° C, freezing level dropping to valley bottom.
Saturday
Mix of sun and clouds with no precipitation, alpine wind northwest 30 to 40 km/h, treeline temperature -8° C.
Sunday
Cloudy with sunny periods with no precipitation, alpine wind west 20 to 30 km/h, treeline temperature -6° C.
Monday
Cloudy with sunny periods with no precipitation, alpine wind southwest 20 to 30 km/h, treeline temperature -7° C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Carefully evaluate bigger terrain features on an individual basis before committing to them.
- Early season avalanches at any elevation have the potential to be particularly dangerous due to obstacles that are exposed or just below the surface.
Avalanche Problems
Wind Slabs
Shifting wind and new snowfall will create fresh wind slabs on leeward terrain and cross-loaded features. Human-triggered are likely near ridge crests and roll-overs in the alpine.
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2
Persistent Slabs
A preserved layer of surface hoar is found down 40 to 70 cm. Although the likelihood of triggering it is unlikely, keep using caution at higher elevations, where the rain crust above the weak layer is thinner or breakable.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 1 - 2.5