Avalanche Forecast
Regions: Bonnington, Crawford, Grohman, Kokanee, Kootenay Boundary, Kootenay Pass, Norns, North Okanagan, Retallack, Rossland, Shuswap, South Okanagan, Valhalla, Ymir.
Storm snow may take time to bond with the crust or surface hoar below.
Be cautious on steep slopes -wind slabs may form at higher elevations, and loose snow sluffs easily in sheltered areas
Confidence
Moderate
Avalanche Summary
On Sunday explosive and rider triggered avalanches were reported to size 1.5. Storm snow was generally less reactive to rider traffic, with widespread loose dry sluffing reported on the buried rain crust in sheltered areas, see below.
Snowpack Summary
Storm totals vary from 15-35 cm throughout the region, with wind effect found at higher elevations.
A widespread rain crust (shown in the photo below) sits below the storm snow, observed at treeline and below treeline elevations. The crust has formed a bed surface for slab avalanche activity and sluffing; it likely extends to mountain top but observations are limited.
Surface hoar may still be present at this interface, in areas that received minimal rainfall early in the storm which is more likely in the far north of the region.
The mid and lower snowpack is well-settled, dense, and generally strong. Treeline snow depths range from 100 to 150 cm.
Weather Summary
Monday Night
Mostly clear skies. 20 to 40 km/h northwest ridgetop wind. Treeline temperatures around -10 °C.
Tuesday
Sunny with increasing afternoon cloud. 20 to 40 km/h northwest ridgetop wind. Treeline temperature -4 °C.
Wednesday
Partly cloudy. 20 to 30 km/h west ridgetop wind. Treeline temperature -4 °C.
Thursday
Cloudy with 3-6 cm of snow. 30 to 40 km/h southwest ridgetop wind. Treeline temperature -5 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be careful with wind-loaded pockets, especially near ridge crests and rollovers.
- Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
- Make observations and continually assess conditions as you travel.
Avalanche Problems
Wind Slabs
Storm snow will be most reactive in wind affected terrain where slab quality exists (cohesion within the storm snow). As slabs rest on a crust or surface hoar we have uncertainty over when this bond will improve.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2