Avalanche Forecast
Regions: Brazeau, Churchill, Cirrus-Wilson, Fryatt, Icefields, Jasper, Maligne, Marmot, Miette Lake, Pyramid.
Solar input will increase the reactivity of wind slabs and persistent slabs. Human-triggered and remote-triggered avalanches remain likely.
Confidence
Moderate
Avalanche Summary
A widespread avalanche cycle occurred last week as a result of the Feb 29th storm. Natural avalanches upto size 3.5 have been observed on the Icefields Parkway - all aspects in the alpine & at tree line running to the end of avalanche paths. Avalanche control along the Icefields Parkway on Friday had several sympathetic avalanche releases from a single explosion.
No new avalanche activity observed on the Icefields Parkway or Malign Lake Road over the past 3 days.
Snowpack Summary
Up to 50 cm of new snow fell during last weeks storm with strong winds, creating wind slabs. Wind slabs sit over a layer of faceted snow above a 1-3cm thick crust that is down 35-60 cm. This persistent weak layer is consistently reactive in snowpit tests and is not going away anytime soon. The mid-pack is faceted with basal depth hoar and well developed facets near ground. HS ranges from 80 to 150cm.
Weather Summary
Mountain Weather Forecast is available @ Avalanche Canada https://avalanche.ca/weather/forecast
Thursday Mix of sun and cloud. Alpine High -10 °C. Wind 15 km/h
Friday Cloudy with sunny periods & isolated flurries. Trace precipitation. Alpine High -7. Wind SW 20 km/h
Saturday Cloudy with sunny periods & isolated flurries. Accumulation 4 cm. Alpine high -3. Wind W 20 km/h gusting to 60. Freezing level 1800m
Terrain and Travel Advice
- Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Avalanche Problems
Wind Slabs
Strong winds that accompanied the +50cm storm have produced wind slabs in the alpine and treeline. Wind direction has switched to North on Wednesday so be on the lookout for reverse loading and be aware that this problem exists on all slope aspects.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 2.5
Persistent Slabs
This problem layer is the crust and facets created by early February's warm spell. It is down 30-80 cm in the snowpack and is a 1-10 cm thick crust.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1.5 - 3
Deep Persistent Slabs
The base of the snowpack is inherently weak and untrustworthy. Tickling this deep layer would result in a high consequence avalanche. Any avalanche in the upper snowpack has the potential to step down to the base of the snowpack.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 2 - 4