Avalanche Forecast
Regions: Bonnington, Crawford, Grohman, Kokanee, Kootenay Boundary, Kootenay Pass, Moyie, Norns, Retallack, Rossland, Valhalla, Whatshan, Ymir.
New snow and wind will make dangerous avalanche conditions.
Avalanches are expected.
Confidence
Moderate
Avalanche Summary
On Monday: A few natural and skier triggered storm slab and wind slab avalanches were reported up to size 2.5 (very large). They happened on north and east aspects in the alpine and at treeline.
Some of these avalanches stepped down to weak layers that are buried in the snowpack.
Snowpack Summary
Snow continues through the day which could add up to 40cm on top of 20 cm of recent snow. This snow sits on a crust on solar aspects and all aspects below 1800 m. Above the crust, surface hoar or facets exist in sheltered areas and on north aspects.
Two concerning weak layers are present in the mid snowpack: facets/surface hoar or a crust from mid-February buried 50-90 cm, and facet/surface hoar/crust from late January buried 80-120 cm.
Weather Summary
Wednesday Night
Cloudy with 5 to 15 cm of snow. 20 to 50 km/h southeast ridgetop wind. Treeline temperature -3 °C.
Thursday
Mainly cloudy with 15 to 25 cm of snow. 30 to 60 km/h west ridgetop wind. Treeline temperature -4 °C.
Friday
Mix of sun and cloud with up to 3 cm of snow. 10 to 20 km/h southwest ridgetop wind. Treeline temperature -3 °C.
Saturday
Mainly cloudy with up to 7 cm of snow. 10 to 30 km/h southwest ridgetop wind. Treeline temperature -1 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be alert to conditions that change with elevation, aspect, and exposure to wind.
- Be aware of the potential for large, destructive avalanches due to deeply buried weak layers.
- Storm slab size and sensitivity to triggering will likely increase through the day.
Avalanche Problems
Storm Slabs
New snow arrives with moderate to strong southwest wind.
This will make deeper and more reactive deposits in lee features.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Very Likely
Expected Size: 1 - 2.5
Persistent Slabs
Weak layers exist 40 to 100 cm deep. These layers remain a concern where there is no thick, supportive crust under the recent snow.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1.5 - 3