Snow amounts are gradually accumulating over a variety of potential weak layers.
Confidence
Moderate - Intensity of incoming weather systems is uncertain on Monday
Weather Forecast
MONDAY: Mainly cloudy with isolated flurries / Light to moderate west wind / Alpine temperature -9 TUESDAY: Cloudy with sunny periods / Light to moderate east wind / Alpine temperature -10 WEDNESDAY: Cloudy with sunny periods / Light north wind / Alpine temperature -15
Avalanche Summary
No new avalanches were reported within this region on Saturday. If you have any observations, please submit them to the Mountain Information Network (MIN).
Snowpack Summary
10-20cm of new snow accumulating Friday through Sunday evening sits on a wide variety of old surfaces including large surface hoar (weak, feather-like crystals), hard crusts formed by sun or wind, and sugary facets. As the snow load builds and slab properties develop, it will be important to monitor how the new snow is bonding to the old surfaces. Most concerning would be areas that have surface hoar sitting on top of a hard crust. A crust which was formed by rain in late November is a major feature in the snowpack and is down approximately 60-80cm at tree line elevations. Snowpack tests suggest the snow above is currently bonding well to it. Snowpack depth decreases rapidly below tree line. Look out for early season hazards such as rocks, stumps, and open creeks.
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.