As this past week's storm snow continues to settle it will still be important to evaluate the bond between the old snow surface and the new snow. There is still potential for a weak sliding layer in isolated sheltered areas.
Confidence
Moderate - Forecast snowfall amounts are uncertain
Weather Forecast
Thursday: Flurries, accumulation 5-10cm / Moderate southwest wind / Alpine temperature -4Friday: Mainly cloudy with isolated flurries / Light northeast wind / Alpine temperature -7Saturday: Sunny with cloudy periods/ Light north wind / Alpine temperature -10
Avalanche Summary
Recent reports from Monday and Tuesday indicate numerous explosive and a few skier triggered storm slab and wind slab avalanches to size 2 in the alpine and treeline at the storm snow/old snow interface . There were also reports of a few remotely triggered avalanches from thin wind scoured ridge crests into adjacent steeper loaded slopes. I would suspect there to be continued potential for skier and rider triggering with some recent very strong winds at upper elevations and a possible weak bond at the storm/old snow interface with buried surface hoar in isolated sheltered areas.
Snowpack Summary
30-50cm of new snow overlies the previous variable snow surface from last week, which includes hard wind pressed or scoured areas, old wind slabs, weak faceted snow, or surface hoar. Moderate to strong southwest wind has redistributed this new snow to form windslabs in the lee of terrain features in the alpine and treeline. The widespread mid-November crust is typically down 1-2m in the snowpack. Recent snowpack and explosive tests have shown the crust to be unreactive, but it could remain a problem in shallow alpine start zones.
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.
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.