Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Little Yoho, Sunshine, West Side 93N.
A natural avalanche cycle is ongoing, with numerous large avalanches being reported and multiple near misses. Avalanche terrain, as well as overhead hazard should be avoided.
Confidence
High
Avalanche Summary
There have been some very close calls from people getting out. One at Crowfoot Glades and one on HWY. 93S. Thanks to those who shared about their incidents, the forecasting team and general public appreciate it!
Additionally, we've seen numerous natural and explosive-triggered avalanches, up to size 3.5 with some avalanches running full path. The potential for large natural avalanches is very real.
Human triggering in avalanche terrain remains likely.
Snowpack Summary
50-90 cm of new snow fell from Feb 23 to March 2. This combined with strong winds has formed a 40-60 cm storm slab in many exposed areas at alpine and treeline elevations. The Feb 3 facets/crust layer is down 50-90 cm and exists up to 2500m. The base of the snowpack consists of facets and depth hoar. This basal layer is weaker in shallow snowpack areas.
Average snowpack depths at tree line range from 110 cm (to the east) to 170 cm (to the west).
Weather Summary
Scattered flurries across the range. Trace accumulations are expected however pay attention to convective snowfall bringing more snow than forecast. Light to moderate westerly ridgetop winds. Freezing levels at valley bottom, with an alpine high of -14C.
Click here for a more detailed weather forecast
Terrain and Travel Advice
- Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
- Remote triggering is a big concern, be aware of the potential for wide propagations and large, destructive avalanches at all elevations.
Avalanche Problems
Storm Slabs
Up to 90 cm of recent snow has formed reactive wind and storm slabs. Recent avalanches have stepped down to deeper layers resulting in large avalanches on the Feb 3 crust, or even bigger avalanches stepping down to weak facets near the ground.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Very Likely
Expected Size: 1.5 - 3
Persistent Slabs
50 - 90 cm of snow overlies the Feb. 3rd crust/facet combination. Numerous natural & skier-triggered avalanches have occurred on this interface. Wide propagations and remote triggering are likely on this layer. Stay clear of avalanche terrain.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Very Likely
Expected Size: 1.5 - 3
Deep Persistent Slabs
Some of the recent avalanches are stepping down to the basal layers near the ground. This seems to be most common in thin, steep, rocky terrain in the alpine. Recent loading has made this layer more sensitive.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 2 - 3.5