Avalanche hazard will rise today if forecast strong winds occur. Use caution in avalanche terrain during periods of heavy loading from new snow and wind.
Weather Forecast
Light snow is forecast today with alpine temperatures around -2 and the freezing level rising to 1400m. Expect ridge top winds to be SW 20 gusting to 80. This weather will continue through Sunday with a break in the precipitation forecast for Monday. Snow is expected to return Tuesday.
Snowpack Summary
45-55cm of storm snow sits over the December 8 surface hoar layer at lower elevations and over variable wind slabs up high. The storm snow is mainly low density with some soft slab developing as temps warm. The November 28 surface hoar layer is down around 60-75cm over a facetted mid-lower snowpack. The Nov 12 surface hoar layer is down 80-110cm.
Avalanche Summary
Yesterday natural avalanches with large powder components occurred. We observed avalanches up to size 2.5 east of Rogers Pass along the highway corridor. The public observed avalanches off the steep north facing terrain off Cheops. Sluffing of the low density surface snow was observed in unsupported terrain, steeper than 35 degrees.
Confidence
Intensity of incoming weather systems is uncertain
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.