~65cm of snow overlies surface hoar or a sun crust; both problematic persistent layers that promote poor bonding, remote triggering, and easy sliding.
Human triggered avalanches are possible to likely on slopes that did not previously avalanche during the storm, especially where the surface feels "slabby".
65cm of snow and strong SW winds formed a slab that sits on a surface hoar layer in sheltered zones, and overlies a sun crust on steep, solar aspects. This slab may be triggered by riders where it is cohesive and stiff enough to slide on the weak layers.
Natural avalanche activity has curtailed in the last 24hrs, with a few loose/dry sz 1-1.5 avalanches observed in the highway corridor in steep/extreme.
Artillery control produced excellent results on Tupper and Macdonald Sat night, with most shots producing sz 2 to sz 3 avalanches from steep start zones, running out onto valley bottom fans. Debris moved fast, likely picking up speed and mass on the buried surface hoar.
Up to 65cm of new snow sits on a sun crust on steep solar aspects. In sheltered locations, this new snow sits atop large surface hoar. Strong SW winds at the end of the storm created surface slab conditions on exposed Treeline and Alpine slopes.
There is a dense, well-settled mid-pack without any significant weak layers.
The Nov 9 crust is down 1-1.5m. The base of the snowpack is comprised of several dense, melt-freeze rain crusts formed in October.
The ridge of high pressure continues, with no significant change in the weather.
Tonight: Mainly cloudy, Alp low -11°C, light W winds, Freezing Level (FZL) 500m.
Tues: Cloudy with sunny periods, Alp high -7°C, light W winds, FZL 800m.
Wed: Clouds, isolated flurries, Alp high -4°C, light SW winds, FZL 1500m.
Thurs: Cloudy, isolated flurries, Alp high -4°C, light S winds, FZL 1300m.
