Regions
Kootenay Boundary.
Avoid thin snowpack areas where a deep persistent layer has been more reactive. See the snowpack discussion for more information.
Weather Forecast
Thursday night and Friday: The ridge of high pressure that has been blocking the weather patterns is beginning to weaken and an upper trough will move in. Cloudy skies and light flurries are expected for the day with moderate winds from the Northwest and cooler more seasonal temperatures in the alpine (-5 C).Saturday: A surface ridge centered over the region will bring a bit of a clearing with few to scattered skies and valley clouds, no precipitation forecasted and moderate Southwesterly winds. Temperatures stay similar.Sunday: A front should move across the region bringing moderate precipitation with light Southwesterly winds and cooler temperatures.
Avalanche Summary
Small loose dry avalanches have been reported in steep terrain and also loose moist avalanches on steep solar aspects.
Snowpack Summary
A variety of surfaces exist on the snowpack including windslabs that were formed by recent NW winds below ridgetops on lee aspects, 15-20 cm of facets due to overnight cooling, surface hoar in shaded aspects at treeline and below treeline and a sun crust on solar aspects. Although size should remain small, I suspect it is possible to trigger windslabs under the weight of a skier below ridgetops and also loose dry snow in steep sheltered terrain. A generally settled upper snowpack overlies the late November surface hoar, buried down 115-130 cm. This layer seems particularly reactive in the Rossland Range and in the central part of the region. A deeply buried crust/facet layer near the base of the snowpack is considered dormant. Although unlikely, there is a lingering possibility of triggering a persistent slab in isolated areas.
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.