Touchy avalanche conditions are expected to persist for a couple more days due to a layer of buried surface hoar.
Confidence
Moderate - Intensity of incoming weather systems is uncertain on Saturday
Weather Forecast
Friday: Mainly clear, no precipitation is expected, light north easterly winds and a freezing level of 500m. Saturday: Snow starting overnight with 10-20cm expected by the end of the day, light southwesterly winds, and a freezing level between 1000 and 700m. Sunday: Snow forecast to continue overnight with another 20 to 30 by the end of the day, light to moderate southerly winds, and a freezing level of 1200m.
Avalanche Summary
There was wide spread avalanche activity on Thursday with numerous natural, explosive controlled, and skier accidental avalanches ranging from size 1-2. These avalanches failed on the layer of surface hoar down 30 to 40cm on all aspects at treeline and in the alpine.
Snowpack Summary
Between 20 and 50 cm of new snow continues to settle into a soft slab sitting above a widespread layer of surface hoar, facets, and/or sun crust on steep south aspects. 10-20 cm below this is a second buried weak layer of surface hoar and/or a crust. The mid and lower snowpack is generally strong, with the exception of shallower snowpack areas that may be more faceted. At lower treeline elevations recent rains have saturated the upper snowpack. At higher elevations moderate southerly winds have formed loaded lee features at treeline and in the alpine.
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.