Regions
Banff Yoho Kootenay.
Recent snow has improved the skiing dramatically, however there is a poor bond at the storm snow interface. Avoid larger features, and steeper terrain. There is lots of good riding on low angled terrain.
Weather Forecast
Christmas day will be cloudy with isolated flurries and an alpine temperature high of minus nine. Friday's forecast is for mixed sun and cloud, and light winds. Only flurries forecasted for the weekend.
Snowpack Summary
At treeline between 10 and 30 cm of snow has fallen since Tues, with the heaviest snowfall occurring in Yoho Park. The new snow overlays the Dec 18 layer which consists of crust, facets and/or surface hoar depending on location. A poor bond exists on this storm snow interface.
Avalanche Summary
In Yoho backcountry several avalanches up to Class 2.5 (with propagations up to 200 m) were observed running in recent storm snow. Lake Louise ski hill reported several natural and skier controlled avalanches running in the storm snow.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.