Avoid steep wind-loaded, northeasterly alpine terrain, as a layer of buried surface hoar proved to be a major hazard today.
Wind slabs may overlay a layer of weak surface hoar in northeasterly alpine terrain. Avalanches have the potential to be large and destructive if triggered on this buried surface hoar. This layer has demonstrated the ability to propagate large distances.
Our Avalanche Canada field team remote triggered a large, wind slab avalanche on a Northeast, alpine slope. Check out more details and photos in their Mountain Information Network report. A few similarly sized natural avalanches were observed on nearby slopes of similar aspect and elevation.
In alpine terrain, recent winds have created a variety of wind-affected surfaces. Isolated wind slabs remain in steep, unsupported, lee terrain features. Below roughly 1700 m a widespread, breakable melt-freeze crust is present, with moist snow below.
A layer of surface hoar has been reported down 50 to 80 cm from the surface.
Friday night
Clear, no precipitation. Moderate northerly alpine winds, with stronger outflows in the valleys. Alpine temperatures -10 to -20 C.
Saturday
Sunny, no precipitation. Moderate northerly alpine winds, with stronger outflows in the valleys. Alpine temperatures -15 to -25 C.
Sunday
Mostly sunny, no precipitation. Light to moderate northwest alpine winds. Alpine temperatures -5 to -10 C with potential for a temperature inversion.
Monday
Cloudy, with isolated flurries. Light to moderate westerly alpine winds. Alpine temperatures -5 to -10 C.
More details can be found in the Mountain Weather Forecast.
