Avalanche Forecast
Regions: Banff Yoho Kootenay.
Continue to expect natural avalanches with ongoing strong SW winds and snow forecasted.
Weather Forecast
For Friday - 5- 15 cm is forecasted with highs -4C and strong SW winds that will diminish over Friday afternoon. Temperatures will fall to -5 to -10C. Another 5- 10 cm expected Saturday with light to moderate wind. The avalanche hazard is expected to remain elevated with these continued inputs.
Snowpack Summary
Approximately 60 cm has fallen in the past week with strong to extreme Westerly winds creating widespread wind slabs. Watch for buried sun crust on steep solar aspects. In thin snow pack areas a dense mid-pack sits over a weak, faceted base. Isolated locations below 1900 m, the Feb 1 crust down may be starting to become reactive.
Avalanche Summary
Local ski hills report ski cutting & explosive controlled wind slabs 15-30 cm thick. One size 2.5 deep persistent release on an alpine solar aspect with explosives & a skier triggered slab on the Feb 1 crust near Sunshine (1700 m).
Several natural storm slabs up to sz 2.5 observed along highway 93S yesterday where intense wind loading was occurring.
Confidence
Avalanche Problems
Storm Slabs
Expect to find wind & storm slab formation on lee aspects and open areas from the alpine to below tree line. Loose dry sluffing from steep terrain is also a concern, especially in gulleys, terrain traps and above cliffs with ongoing wind & snowfall.
- Watch for fresh storm slabs on exposed lee slopes and open areas at all elevations.
- 1002
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely - Very Likely
Expected Size: 1 - 2.5
Deep Persistent Slabs
Avalanche activity on the basal facets has slowed down but the weakness in the snowpack remains a concern. These are hard to predict, but are most likely in areas with a thin snowpack (<130cm) where the basal facets and depth hoar are prominent.
- Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.
- Use caution in thin snowpack areas.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 2 - 3.5