A touchy surface hoar layer below the recent storm snow has heightened the chance of skier triggered slides. It is a good time for conservative terrain choices.
Weather Forecast
Sunny with cloudy periods, a trace of snow and alpine temperatures in the -12C range. Thursday should give us light flurries, moderate westerly wind and alpine temperatures of -10C.
Snowpack Summary
40cm of storm snow sits on top of the Dec 15 surface hoar/persistent weak layer. On steeper solar aspects this layer is a crust and/or a crust with small surface hoar on top. The crust runs well up into the alpine on steep south aspects. Deeper in the pack there are a series of crust layers that are currently well bonded to neighboring layers.
Avalanche Summary
A natural avalanche cycle has been continuing over the last 48hrs with over 40 avalanches up to size 3 recorded in the highway corridor. Most slides have been in the size 1.5 to 2 range failing on the Dec 15th surface hoar layer. Avalanches have been on all aspects and elevations including numerous below treeline events.
Confidence
Forecast snowfall amounts are uncertain on Thursday
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.