Regions
Banff Yoho Kootenay.
We will see a slow rise in hazard through the early part of this week. New wind slabs building over the November rain crust will be the layer to watch for as more snow arrives.
Weather Forecast
Light flurries, tree line temperatures between -7'C and -15'C, and Light to Moderate SW winds will continue through Tuesday. Wednesday we expect to see more significant snow throughout the forecast area.
Snowpack Summary
Below treeline there is not enough snow for avalanches. Above 1900m a buried rain crust that formed in early November lies 20-40cm above the ground. This along with surface hoar in some areas is being buried by light snow this weekend and may create a sliding layer. Some lee slopes will have thin wind slabs.
Avalanche Summary
One small skier triggered avalanche was reported in the Bow Summit Area a few days ago. Ski hills are seeing small (1.5) wind slabs 20-40cm thick being triggered in very steep terrain. These are not yet big enough to bury a skier or climber, but could push you off of a cliff or into a terrain trap.
Confidence
Timing, track, or intensity of incoming weather system is uncertain on Tuesday
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.