Confidence
Fair - Timing, track, or intensity of incoming weather system is uncertain on Sunday
Weather Forecast
Saturday: Light to moderate snowfall with moderate westerly ridgetop winds. Freezing level around 1400 m.Sunday: Moderate to locally heavy snowfall with strong westerly winds. Freezing level around 1400m.Monday: Light to moderate snowfall with light southwest winds. Freezing level dropping to 1000m
Avalanche Summary
No recent avalanche activity has been reported.
Snowpack Summary
Snowpack depths at treeline are approximately 70-100cm. On the surface light amounts of new snow override a variety of old surfaces which include: old wind slabs, melt-freeze crusts and surface hoar.Probably the most important layer we've heard about in this region is a crust near the base of the snowpack that has sugary facets associated with it. In mid November, several large avalanches were reported on this weakness. A recent snowpack test in the backcountry near Kicking Horse on a NW aspect gave moderate but "sudden" results, indicating this layer is likely still triggerable. While this layer is probably slowly gaining strength, it may 'wake-up' with the new snow load forecast for the weekend. The most likely place you'd trigger this layer is on smooth, planar, north facing slopes, especially if the snowpack is unusually shallow in that area.
Problems
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.
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.