Avalanche Forecast
Regions: Brazeau, Churchill, Cirrus-Wilson, Fryatt, Icefields, Jasper, Maligne, Marmot, Miette Lake, Pyramid.
Happy New Year! The deeper weak layer has potential to be human-triggered. A special avalanche warning has been issued which includes our region.
Be extra cautious in wind affected areas where a stiffer slab can propagate widely.
Confidence
Moderate
Avalanche Summary
There was no field patrol on Saturday. Wednesday to Thursday's avalanche control on some low targets along the Icefields Parkway produced several large slab avalanches in wind loaded tree line slopes. They triggered as the persistent slab and stepped down to the deep persistent slab near ground. Below tree line slopes produced small slab avalanches. Numerous natural avalanches up to size 2.5 were also observed in the alpine along the Icefields Parkway on these same days.
Snowpack Summary
20-30 cm of surface snow has developed into a slab over the December 17th facets. Alpine and tree line slopes are heavily wind affected. Facets and depth hoar make a weak base in most areas. Snow height ranges from 50-120cm.
Weather Summary
New Year's Eve will be cloudy, clear periods, isolated flurries, -10 °C, and light West winds. New Year's day is cloudy with sunny periods and -10 °C. Monday and Tuesday is very similar with sun and cloud, light winds, -16°C overnight and -6 °C during the day.
Terrain and Travel Advice
- Make conservative terrain choices and avoid overhead hazard.
Avalanche Problems
Persistent Slabs
Surface snow and strong winds have formed a slab over the December 17th facet layer 25-50cm down. This is most significant at tree line and in the alpine in exposed locations and exists in some areas below tree line. If triggered, it can step down and initiate a deep persistent slab on the basal facets near ground.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1.5 - 2.5
Deep Persistent Slabs
The bottom of the snow pack is inherently weak with well developed Facets and Depth Hoar.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1.5 - 3