Continued loose snow avalanches on steep alpine and tree line slopes. Be prepared for these sloughing on or under slopes and ice climbs .
Weather Forecast
Light NW winds with the possibility of some light snow flurries can be expected on Saturday. Cool overnight temperatures will warm to above seasonal values by the afternoon with sunny breaks.
Snowpack Summary
Moderate to strong SW winds have created slab conditions on open tree line slopes and along ridge lines in the alpine. The mid-pack is facetting but remains strong where it is deeper than a meter. In shallow areas, facetting has weakened it significantly.
Avalanche Summary
In the past 2 days, surface facets have created numerous small loose avalanches at tree line and above in the Icefields area. These slides have little mass and have not as yet triggered the wind slabs beneath them. No natural slab avalanches were observed today.
Confidence
Due to the number and quality of field observations on Saturday
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.