Regions
Banff Yoho Kootenay.
The great skiing continues...but make sure you stop, dig down and test for the Dec 3 surface hoar layer that is present below 2000m in many locations. This is particularly relevant in areas near the divide with a deeper snowpack.
Weather Forecast
We expect to see a few cm's of snow and increasing SW winds on Saturday night and into Sunday. Temperatures will be slightly warmer ranging from -2 to -10'C.
Snowpack Summary
In sheltered terrain below 2000m, a 30-40 cm soft slab sits over the December 3rd surface hoar. This layer continues to produce whumphs and easy shears in many locations, especially in areas to the West with more snow. No other significant shears have been observed. In the alpine isolated wind slabs exist in immediate lee areas.
Avalanche Summary
No new avalanches observed today in our forecast area. Ski cutting produced some small slabs on the Dec 3 SH in steep terrain below tree line near Bow Summit. Kananaskis Country reported one size 2.5 natural avalanche out of steep wind loaded alpine terrain in the Hero's Knob area.
Confidence
Due to the number of field observations
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.
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.