Regions
Banff Yoho Kootenay.
With some careful route finding to avoid the problems described, you can find some great skiing! Expect less sluffing from cliffs tomorrow as the wind backs off.
Weather Forecast
Significant snow fall has subsided, temperatures will continue to cool and winds will taper. Cloudy skies and light flurries are forecast for the remainder of the week.
Snowpack Summary
The Dec 3rd interface is buried by 35 - 70 cm of snow (the greatest amount around Bow Summit). Lots of settlement of the new snow increasing it's slab like property. The Dec 3 layer is the key weakness and it consists of facets and large surface hoar below 2000m, wind effect in the alpine, and suncrusts on steep S & SW aspects.
Avalanche Summary
Size 1 wind slabs in immediate lees of alpine terrain ski cut and with explosive work in the Louise area. Size 1 sluffs off steep cliffs triggered by wind gusts today. Some cracking has been observed in a steep below treeline glades where the Dec. 3rd surface hoar is present. Again, limited observations in the alpine due to poor visibility.
Confidence
Due to the number of field observations
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.
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.