Avalanche Forecast

Fair - Due to variable snowpack conditions on Saturday

Overnight and Saturday: A ridge of High pressure is forecast to move into the interior regions during the night or early morning. Expect moderate Northwesterly winds as the ridge moves over the region and the alpine temperatures drop into the minus teens. There may be a few more cms of snow before the moisture is pushed to the east by the ridge. Broken skies with sunny periods in the afternoon.Sunday: Generally clear and cold in the morning, becoming high overcast in the afternoon. Some snow should begin to fall in the evening in the North of the region, and all areas should see some snow by morning. Moderate Northwesterly winds are expected to continue.Monday: A warm front with moderate precipitation and strong Westerly winds is forecast to move into the region from the coast.

Professionals working in the Southern Selkirks experienced a very large settlement that propagated a fracture about one kilometre (1000 metres) on Wednesday. The fracture was reported to have traveled through some forest and across several pieces of avalanche terrain without releasing an avalanche. The loud whumph was the result of a failure on the deeply buried early November rain crust. After this experience, some explosive control from a helicopter resulted in a size 3.0 avalanche releasing on the buried crust that was approximately 200 cms below the surface. There was also natural and explosives controlled avalanches on the November 28th surface hoar layer that is buried down 40-70 cms.

There are wind slabs of varying thickness and stiffness in the alpine and at treeline that were formed earlier in the week from very strong winds and warm temperatures during the storm. There is a surface hoar layer (November 28th) that is buried between 40-70 cms as the slab above has become more consolidated. This layer appears to be mostly between 1600-2000 metres in elevation, and may be very reactive in areas that experienced valley fog last week when it formed. The big unknown is the deep persistent weak layer (DPWL) of early November rain crust. This layer formed in early November when a warm rain event extended well up into the alpine and than froze into an ice layer. This layer is found where there was enough snow on the ground at the time of this event to become saturated and then freeze. Large scree slopes, areas where snow was still on the ground from last winter, and some smooth glaciers are the most suspect locations.