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
A mix of sun and cloud for Saturday with moderate northwesterly winds and alpine temperatures around -10. Sunday should be mainly cloudy with light flurries. Ridgetop winds are expected to increase to moderate to strong westerlies and alpine temperatures around -10. Expect to wake up Monday morning with 5-10 cm of fresh snow in the mountains with an additional 5-10 cm throughout the day, all falling under strong southwesterly winds. Freezing levels are expected to rise as high as 1300 m by Monday afternoon.
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
30-70 cm of faceted powder overlies the previous variable snow surface from last week, which includes 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.