Avalanche Forecast
Regions: Tumbler.
Evaluate snow conditions as you transition into open terrain features, and be on the lookout for signs of instability like shooting cracks. Stiff, wind deposited snow can be expected to avalanche under the weight of a rider.
Avoid shallow, rocky snowpack areas where triggering the deep persistent weak layer is still possible
Confidence
Low
Avalanche Summary
No new avalanches have been reported, but field information is very limited in this region.
We suspect users who head to the backcountry will see evidence of a natural wind slab avalanche cycle from recent storm snow and strong southwest winds.
Snowpack Summary
20-25 cm of snow from early this week is being redistributed by southwest winds into lee terrain in wind-exposed areas and at upper elevations. This overlies previous wind slabs and, a melt-freeze crust found on sun-exposed slopes and everywhere below 1600 m.
Several crust/facet/surface hoar layers exist in the upper and middle portions of the snowpack. The most concerning persistent weak layer is at the base of the snowpack from large and weak facets formed in November. This layer is widespread and most likely problematic in steep, rocky alpine terrain.
In general, the snowpack is weak and shallow in this area with an average snowpack depth of 100 cm at treeline.
Weather Summary
Thursday Night
Clear. Ridge wind from the southwest 40-60 km/h. Alpine temperatures low of -5 C. Freezing level 700m.
Friday
Cloudy with sunny periods and isolated flurries, trace accumulation. Moderate ridge wind from the west gusting 60 km/h. Alpine temperatures rise to -3 C. Freezing level 1000m.
Saturday
Sunny with cloudy periods and isolated flurries, trace accumulation. Ridge wind from the west 60 km/h. Alpine temperatures rise to -4 C. Freezing level 1000m.
Sunday
Partly cloudy with isolated flurries, trace accumulation. Ridge wind from the southwest 60 km/h. Alpine temperatures rise to -2 C. Freezing level 1400m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Use ridges or ribs to avoid areas of wind loaded snow.
- Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
- Avalanche hazard may have improved, but be mindful that deep instabilities are still present.
Avalanche Problems
Wind Slabs
+20 cm of storm snow and southwest winds are building fresh wind slabs in treeline and alpine lees. Approach lee and cross-loaded terrain with caution.
Keep in mind that wind slabs have the potential to step down to deeper weak layers, resulting in large and consequential avalanches.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2
Deep Persistent Slabs
A layer of large and weak facets sits near the base of the snowpack. This layer is most prominent in upper treeline and alpine elevations. Riders are most likely to trigger an avalanche on this layer in steep, shallow terrain. Your best defence is to stay diligent in choosing low-consequence terrain away from overhead exposure. See more on the potential of triggering deeper weak layers in our latest Forecasters' Blog.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Unlikely - Possible
Expected Size: 2 - 3.5