Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain on Saturday
Weather Forecast
Thursday: Cloudy with light snow starting in the afternoon, freezing levels rising as high as 500m and moderate northwesterly winds becoming strong southwesterlies with the onset of precipitation. Friday: Snow easing throughout the day with 10-15cm total since Thursday, moderate northwesterly winds and freezing levels hovering around 500m. Saturday: Heavy snow, extreme southwesterly winds and freezing levels rising as high as 1000m.
Avalanche Summary
There have been reports of small human triggered wind slabs over the past few days. Most activity seems to be in high alpine start zones.
Snowpack Summary
Recent winds have been stiffening the low density storm snow and forming reactive slabs. Below these recent storm snow weaknesses, the snowpack is well settled and strong. A layer of surface hoar that formed during late November has been found intact or decomposing in some locations down a meter or more. The early November crust/facet combination near the base of the snowpack seems to be dormant, at least in deep snowpack areas where it is buried too deeply by a stiff snowpack to be affected by light triggers on the snow surface.
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.