Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Little Yoho, Sunshine, West Side 93N.
Natural and human triggered avalanches are still occurring with large avalanches observed and multiple near misses. Avoiding avalanche terrain and overhead hazard is the only reliable way to deal with the current snowpack.
Avalanche control takes place March 4 on Vermillion Peak, Simpson Area, Mt Stephen and Cathedral Glades.
Confidence
High
Avalanche Summary
Natural and human triggered avalanche activity continues with numerous natural, human and explosive triggered avalanches up to size 3.5 with some avalanches running full path.
The potential for large natural avalanches is very real, and human triggering remains likely.
There have been some very close calls at Lipalian, Crowfoot Glades and HWY 93S. Thanks to those who shared about their incidents, the forecasting team and general public appreciate it!
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 at alpine and treeline elevations. The weak Feb 3 facet/crust layer is down 50-90 cm and exists up to 2500 m and higher on steep solar aspects. The lower snowpack consists of several facet layers and depth hoar. The basal layer is weaker in shallow snowpack areas.
Weather Summary
A mix of sun and clound with scattered flurries on Monday. 1-3 cm of snow is expected with higher amounts possible in convective flurries. Light to moderate westerly ridgetop winds. Alpine temperatures stay around -17°C and treeline temperatures hover between -8 and -12°C. Freezing levels remain at valley bottom though sunny breaks may heat up solar aspects.
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
Recent snow has settled into 35-60 cm deep wind and storm slabs. Lots of storm slab avalanches have occurred. Some of these have also stepped down to deeper layers resulting in large avalanches on the Feb 3 crust/facet interface, or even bigger avalanches on the weak facets near the ground.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1.5 - 3
Persistent Slabs
50-90 cm of snow overlies the weak Feb 3 crust/facet interface. Numerous natural and skier-triggered avalanches have occurred on this interface. Wide propagations and remote triggering remain likely on this layer. Avoiding avalanche terrain is the only reliable way to deal with this layer .
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1.5 - 3
Deep Persistent Slabs
Some recent avalanches are stepping down to the weak basal facet and depth hoar layers near the ground resulting in large avalanches. This seems to be most common in thin, steep, rocky terrain in the alpine. Recent snow loading has made this layer more sensitive to natural and human triggering.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 2 - 3.5