Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Sunshine, West Side 93N.
Ski quality has gone way up with the new snow, however, the persistent layer of weak facets from Jan has not changed much and continues to be a major concern. There is also potential for an increase in hazard with solar heating on Sunday.
Enjoy the fresh snow but continue to approach any steep terrain with caution.
Confidence
Low
Avalanche Summary
Visibility has been limited for a couple of days, but natural avalanche activity has slowed down due to cooling temperatures and light winds.
Local ski hills reported triggering small storm slabs up to size 1.5 with ski cutting and explosives. Loose-dry avalanches have been reported in steep gullies and on steep faces.
Large whumpfs on the weak Jan/Feb facets continue to be reported and this layer remains a major concern in many areas of the forecast region.
Snowpack Summary
15-35 cm of storm snow over the past two days with the most in the Banff/Kootenay areas of the forecast region. This new snow overlies rain and temperature crusts up to ~2500 m.
A 50-100+ cm dense slab now sits over a persistent weak layer of facets from Jan/Feb.
In Eastern areas with a thinner snowpack, these weak facets and depth hoar extend to the ground. In thicker snowpack regions west of the divide, the facet layer is not as pronounced and the lower snowpack is more settled.
Weather Summary
Saturday night: Cloudy with light flurries and a few cm's of new snow.
Sunday: A mix of sun and cloud. Nil to trace amounts of precipitation. Alpine temps: Low -9 °C, High -1 °C. Ridge wind light from the S/SE around 15 km/h. Freezing level: 2100 m. Possible alpine temperature inversion.
Terrain and Travel Advice
- Uncertainty is best managed through conservative terrain choices.
- Be mindful that deep instabilities are still present and have produced recent large avalanches.
- Give the new snow several days to settle and stabilize before pushing into bigger terrain.
- Avoid terrain traps such as gullies and cliffs where the consequence of any avalanche could be serious.
Avalanche Problems
Persistent Slabs
A 60-100+ cm slab of dense snow now sits atop the persistent mid-pack facet layer from Jan/Feb. In thin snowpack areas weak depth hoar extends to the ground. There has been a lot of large avalanche activity on this facet layer, and where it hasn't avalanched, triggering it remains a major concern.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1.5 - 3.5
Storm Slabs
15-35 cm of storm snow now buries previous crusts and winds slabs. This new snow could fail as a storm slab in steep terrain, and has potential to step down to deeper weak layers in the snowpack. Any significant solar inputs on Sunday will increase the likliehood of these slabs being triggered.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2
Loose Dry
The new snow from the past couple of days will sluff easily in steep terain, and will become more reactive with any significant solar heating inputs on Sunday. Minimize or avoid exposure to overhead hazard in any steep or gullied terrain and manage sluffs carefully while skiing.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2