Avalanche Forecast
Regions: Bonnington, Crawford, Goat, Grohman, Kokanee, Kootenay Boundary, Kootenay Pass, Moyie, Norns, Retallack, Rossland, St. Mary, Valhalla, Whatshan, Ymir.
Recent avalanches in the region indicate that the potential for rider triggering remains possible.Evaluate slopes individually before committing to the terrain.
Confidence
Moderate
Avalanche Summary
On Wednesday, several natural and skier-triggered avalanches were reported across the region. They were mostly small with a few large occurrences, (sizes 1-2) and released on a variety of aspects at treeline and the alpine. They all failed within the recent storm snow or on the persistent weak layers described in the snowpack summary.
This avalanche activity indicates that storm snow and persistent slabs may continue to be reactive to rider triggering.
Snowpack Summary
5 to 20 cm of recently fallen snow overlies previous wind wind-affected or crusty surfaces. A sun crust or moist snow exists on steep south and west faces.
Around Nelson, Kootenay Pass, and the Valhallas, a weak layer of surface hoar may be buried 20-40 cm below the snow surface.
A persistent weak layer of facets may be overlying a thick crust buried 30 to 50 cm.
The mid and lower snowpack is generally well settled.
Weather Summary
Thursday Night
Cloudy with a trace of new snow, 20 km/h south ridgetop wind, treeline temperature around -3 °C, freezing level dropping to 400 m.
Friday
A mix of sun and cloud with no new snow, 25 km/h southwest ridgetop wind, treeline temperature around 2 °C, freezing level rising to 1700 m.
Saturday
Mostly cloudy with 0 to 2 cm of snow, 25 km/h west ridgetop wind, treeline temperature around 1 °C, freezing level rising to 1700 m.
Sunday
Cloudy with a 5 to 20 cm, 45 km/h west ridgetop wind, treeline temperature around 0 °C, freezing level rising to 1500 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
- Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
- If triggered loose wet avalanches may step down to deeper layers resulting in larger avalanches.
Avalanche Problems
Storm Slabs
Storm slabs are likely to be more reactive on lee north and east facing terrain if recent wind effect is present.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 2
Persistent Slabs
Persistent slabs may be triggerable in areas where winds have formed a slab above a layer of facets overlying a crust. Avalanches on this layer could propagate wider and run farther than expected.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely
Expected Size: 1.5 - 2.5
Loose Wet
Aspects: South East, South, South West, West.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 1 - 1.5