Avalanche Forecast
Regions: Bonnington, Crawford, Flathead, Grohman, Kokanee, Kootenay Boundary, Kootenay Pass, Lizard-Flathead, Moyie, Norns, Retallack, Rossland, St. Mary, Valhalla, Ymir.
Avoid all avalanche terrain.
If the sun comes out in the afternoon expect another natural avalanche cycle.
Confidence
High
Avalanche Summary
Numerous large (size 2) slab and wet loose avalanches were reported on Sunday.
On Tuesday and Wednesday, there were also human-triggered persistent slab avalanches getting remotely triggered on the buried facets.
Snowpack Summary
The snowpack is losing strength and becoming soaked by rain and high temperatures.
The snowpack has two buried weak layers of concern:
A layer of facets and surface hoar buried 30 to 60 cm deep, covered by a thin crust at lower elevations but remaining active higher up.
A crust and facet combo from the new year down 80 to 100 cm. This layer seems to be becoming active now that it has a significant load over it from the continued trickle of snow.
Currently, the mid and lower snowpack is generally well-bonded, featuring a thick crust near its base.
Weather Summary
Sunday Night
Cloudy with no new snow, southwest alpine wind 30 km/h, treeline temperature 1 °C, freezing level 2250 m.
Monday
Cloudy with a trace of snow or rain, south alpine wind 35 to 50 km/h, treeline temperature 2 °C, freezing level 3000 m.
Tuesday
Mostly cloudy with 5 cm of snow, south alpine wind 45 to 60 km/h, treeline temperature 2 °C, freezing level 2000 m.
Wednesday
A mix of sun and cloud with no snow, south alpine wind 35 to 45 km/h, treeline temperature 4 °C, freezing level 2250 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Make conservative terrain choices and avoid overhead hazard.
- Avoid steep convex slopes.
- The more the snow feels like a slurpy, the more likely loose wet avalanches will become.
Avalanche Problems
Wet Slabs
Expect wet slabs to be most reactive in areas where it rained a lot or when the sun comes out.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely - Very Likely
Expected Size: 1.5 - 3
Persistent Slabs
There are two layers of concern: Surface hoar and facets buried 30 to 60 cm deep, and facets over a crust 70 to 100 cm down. These MIN reports, one and two, perfectly capture the problem.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 2 - 3
Loose Wet
If the sun comes out in the afternoon expect another avalanche cycle.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Very Likely
Expected Size: 1.5 - 2.5