Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Regions
Banff Yoho Kootenay.
A couple close calls recently with avalanches failing on the mid-pack facets highlight the need to use caution in steep terrain. There is some great skiing to be had above treeline but stick to moderate angled terrain with low consequences.
Weather Forecast
A cooling trend is expected to continue over the next two days with light West winds and occasional light flurries. The freezing level is expected to be around the surface overnight, rising to 1600m during the day.
Snowpack Summary
5-10 cm of new snow Monday, becoming moist below 1700m. Buried sun crusts on solar aspects. Recent moderate West winds have formed wind slabs in lee areas of the alpine. A firm upper snow pack sits over a generally weak mid-pack of facets and depth hoar. In shallow areas snowpack tests results are typically collapses near the ground.
Avalanche Summary
Monday a skier accidental size 2.5 on the Collie Glacier, at 2600m, approaching the Richard and Louise Guy Hut from Mt Collie. The avalanche failed on the Jan 6th mid-pack facets and was triggered when crossing below a steep rocky slope in poor visibility. 2 partial burials with minor injuries. Sunday a skier accidental size 2.5 near Bow Summit.
Confidence
Due to the number and quality of field observations
Problems
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.
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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.