Regions
South Coast Inland.
Beware of wind-loaded and sun-exposed slopes where the recent storm snow has settled into touchy slabs.
Confidence
Moderate - Wind effect is extremely variable
Weather Forecast
On Friday expect a mix of sun and cloud with moderate northerly winds and alpine temperatures around -15. Mainly cloudy for Saturday with moderate to strong northwesterly winds and alpine temperatures in the -10 to -15 range. Sunday should also be mainly cloudy with a chance of flurries late in the day. Ridgetop winds are expected to increase to strong westerlies and alpine temperatures increasing to -10.
Avalanche Summary
No new avalanches have been reported, but expect the recent storm snow to be reactive to light triggers in areas where it has settled into a cohesive slab, such as lee slopes near ridgecrests and terrain breaks and sun-exposed slopes.
Snowpack Summary
Surface hoar is growing and surface snow is faceting. 30-70 cm of low density snow recently buried the previous variable snow surface, including hard wind pressed or scoured areas, old wind slabs, weak faceted snow, or small surface hoar. Wind slabs that have formed in response to southwest winds during the storm, or subsequent northerly winds, are sensitive to light triggers with recent reports of easy hand shears and cracking around skis. In the Duffey Lake area, recent snowpack tests gave moderate sudden planar results down 36 cm on buried surface hoar. Weaknesses have also been found within the recent storm snow with reports of moderate snowpack test results on preserved stellars down 48cm in the Coquihalla Pass area. The widespread mid-November crust typically down around a metre. Recent snowpack tests have shown the crust to be unreactive, but it could become 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.