Avalanche Forecast
Regions: Churchill, Cirrus-Wilson, Fryatt, Icefields, Jasper, Miette Lake.
Natural cornice failure and wind slabs have been triggering large avalanches in the Deep Persistent Weak Layers. Natural activity is tapering, but the likely hood of human triggered avalanches still remains high.
Confidence
Moderate
Avalanche Summary
Friday there was evidence of a Na cycle up to Size 3. Better visibility on Saturday showed continued evidence of this cycle. The avalanches are initiating with cornice fall or in the Wind Slab and stepping down to the basal facets.
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Snowpack Summary
5cm of new snow with strong to extreme SW winds in the alpine on Friday. Freezing levels have dropped since Friday and left a new crust below 2200m. A layer of surface hoar and facets is down 20-40cm in sheltered areas. Large facets and depth hoar comprise the bottom portion of the snowpack. Snowpack depths vary from 50-100cm.
Weather Summary
Sunday
Mainly cloudy with isolated flurries.
Precipitation: Trace.
Alpine temperature: High -4 °C.
Ridge wind light to 15 km/h.
Freezing level: 1600 metres.
Monday
Cloudy with sunny periods and isolated flurries.
Precipitation: Trace.
Alpine temperature: Low -8 °C, High -6 °C.
Ridge wind southwest: 15-25 km/h.
Freezing level at valley bottom.
Tuesday
Cloudy with sunny periods and isolated flurries.
Precipitation: Trace.
Alpine temperature: Low -12 °C, High -8 °C.
Ridge wind southwest: 15-35 km/h.
Freezing level at valley bottom.
Detailed weather forecasts from Avalanche Canada: https://avalanche.ca/weather/forecast
Terrain and Travel Advice
- Make conservative terrain choices and avoid overhead hazard.
- Caution around slopes that are exposed to cornices overhead.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Avalanche Problems
Deep Persistent Slabs
The bottom of the snow pack is inherently weak with well developed Facets and Depth Hoar. Avalanches initiating in the upper snowpack are likely to step down to this layer and gain significant mass.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1.5 - 3
Wind Slabs
Winds and new snow creating wind slabs in lee features
Aspects: North, North East, East, North West.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 2
Cornices
Rising freezing levels were resulting in cornice failures on Friday. These cornices were triggering large avalanches.
Aspects: North East, East, South East.
Elevations: Alpine.
Likelihood: Possible - Likely
Expected Size: 1.5 - 2.5