Regions
South Coast Inland.
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 week sliding layer in isolated sheltered areas.
Confidence
Moderate - Forecast snowfall amounts are uncertain on Thursday
Weather Forecast
Thursday: Flurries, accumulation 5-10cm / Moderate southwest wind / Alpine temperature -2Friday: Mainly cloudy with isolated flurries / Light northeast wind / Alpine temperature -5Saturday: Mix of sun and cloud/ Light north wind / Alpine temperature -8
Avalanche Summary
Recent reports in the Duffy Lake area indicate a few natural avalanches running to size 2 in the alpine. I would suspect there to be continued potential for skier and rider triggering with the recent new snow, strong winds at upper elevations and a possible weak bond at the storm/old snow interface the possibility of buried facets or surface hoar in isolated sheltered areas.
Snowpack Summary
30-60cm 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. New wind slabs that have formed in response to southwest winds. In the Duffey Lake area, recent snowpack tests gave hard sudden results down 60 cm at the interface between the recent storm snow and old snow on rounding faceted crystals. The widespread mid-November crust is typically down approximately 1-1.5m. Recent snowpack tests have shown the crust to be unreactive, but it could become a problem in shallow alpine start zones.
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.