Expect the avalanche danger to rise over the next few days with increasing temperatures, snowfall and strong winds
Confidence
Moderate - Forecast snowfall amounts are uncertain on Sunday
Weather Forecast
Sunday: Flurries, accumulations 10-15cm / Moderate to strong southwest wind / Alpine temperature -7Monday: Snow, accumulations 20-30cm / Moderate to strong southwest wind / Alpine temperature -7Tuesday: Cloudy with flurries, accumulations 5-10cm / Moderate to strong wind / Alpine temperature of -6
Avalanche Summary
No significant new avalanche activity has been reported.
Snowpack Summary
Up to 10cm of new snow overlies the previous variable snow surface from late last week, which includes hard wind pressed or scoured areas, old wind slabs, weak faceted snow, or small surface hoar. The cold temperatures appear to be preserving the old (now buried) wind slabs from the end of last week and they still may be reactive to human triggering in isolated areas. Recent snowpack tests near Whistler gave hard but sudden results in faceted snow under the old hard wind slab. Moderate southwest winds over the weekend and more recent northerly winds have formed soft wind slabs in immediate leeward features. 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.