Stiff wind slabs may continue to be reactive to human triggers at upper elevations. Steep, unsupported terrain and wind-loaded features are most suspect.
Weather Forecast
FRIDAY NIGHT: Cloudy with clear periods. Alpine temperatures near -26C. Ridgetop winds strong from the northeast.SATURDAY: Mostly sunny. Alpine temperatures near -15C. Ridgetop winds strong decreasing to moderate from the northeast.SUNDAY: Sunny with cloudy periods. Alpine temperatures near -15C. Ridgetop winds light to moderate from the northeast.MONDAY: Cloudy with clear periods. Alpine temperatures near -14C. Ridgetop winds light from the east.
Avalanche Summary
Pockets of wind slab were reactive to skier traffic this week, resulting in avalanches up to size 2 in the alpine.
Snowpack Summary
Alpine terrain is heavily wind affected to varying degrees on all aspects. The 40-50 cm of new snow from last weekend has been redistributed initially by strong southwesterly winds and now northerly outflow winds forming reactive pockets of wind slab. This recent snow sits on a crust on all aspects below 2000m and solar aspects into the alpine. In isolated sheltered terrain and treeline and below, a layer of weak feathery surface hoar or sugary facets may be identified, but with little reactivity. Current cold temperatures are promoting surface faceting and may be breaking down the buried crust.The remainder of the snowpack is generally well-settled.
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.