Avalanche Forecast
Regions: Bonnington, Grohman, Kootenay Boundary, Kootenay Pass, Moyie, Norns, Rossland, South Okanagan, St. Mary, Ymir.
Use extra caution on wind-loaded slopes and near ridgetops. Southwest wind is forming the recent snow into reactive wind slabs.
Confidence
High
Avalanche Summary
Riders and explosive avalanche control have recently caused several small (size 1 to 1.5) loose dry and wind slab avalanches within the recent storm snow.
West of Kimberly, a large (size 2) avalanche was reported that was remotely triggered by a rider from 50 m away. See the MIN report for more information.
Expect these types of avalanches to continue occuring in steep, leeward, and cross-loaded terrain in the alpine and at treeline.
Snowpack Summary
15 to 30 cm of recent soft snow has been blown into wind slabs in cross-loaded and lee terrain features from sustained southwest wind. In terrain sheltered from the wind, the recent snow overlies small surface hoar crystals. The surface hoar rests on previously wind-affected snow at higher elevations, faceted soft snow in wind-sheltered terrain, and a melt-freeze crust on sun-exposed slopes and below approximately 1800 m.
Deeper weak layers in the snowpack have not recently produced avalanches, but they may become reactive again if there is a rapid change in the weather.
A surface hoar layer buried in early January is 40 to 80 cm deep. Its distribution is spotty, but it can still be found in wind-sheltered and shaded terrain features.
The lower snowpack contains weak and faceted grains.
Weather Summary
Sunday Night
Cloudy. 0-2 cm of snow expected. Light to moderate west or northwest ridgetop wind. Freezing level 1250-1500 m.
Monday
Cloudy with a possible sunny period in the morning. Possible trace of snow expected. Moderate west or southwest ridgetop wind. Possibly stronger and more northwesterly at very high elevations. Freezing level 1250-1500 m.
Tuesday
Mostly cloudy. 4-8 cm of snow expected. Moderate west or southwest ridgetop wind, possibly strong at high elevations. Freezing level around 1250 m.
Wednesday
Mix of sun and cloud. 4-12 cm of snow expected overnight and through the day. Moderate to light west or northwest ridgetop wind. Freezing level dropping to valley bottom.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Approach lee and cross-loaded slopes with caution.
- Wind slabs are most reactive during their formation.
- Start on smaller terrain features and gather information before committing to bigger terrain.
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
Avalanche Problems
Wind Slabs
Riders could trigger wind slabs in leeward and cross-loaded terrain features near ridgetops due to recent snow and variable wind.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2