Regions
Banff Yoho Kootenay.
Now is an excellent time to put your snow profile skills to work - the Dec 3 surface hoar layer is widespread below 1800 m. Dig down, look for this layer, and test it - this has the potential to become a tricky persistent slab avalanche problem.
Weather Forecast
The main storm pulse is now over for the Rockies, but expect Friday to be overcast with flurries and accumulations of a few centimeters. Temperatures will range from -4 to -10 and winds will be light to moderate from the west.
Snowpack Summary
50-70 cm of storm snow has fallen over the past 7 days, now settled into a cohesive slab overlying a significant weak layer of surface hoar below treeline (and just into treeline). Distribution of this layer is still vague, but you should assume it's widespread below 1800 m. In the alpine, winds from the recent storm have left widespread windslabs.
Avalanche Summary
Avalanche control at the Sunshine ski resort produced small slab avalanches in leeward areas, but otherwise no significant avalanches have been reported - keep in mind that backcountry observations have been very limited over the past week.
Confidence
Due to the number of field observations
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.
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.