Avalanche Forecast
Regions: South Columbia.
Avalanche activity related to last week's storm has slowed down but several buried weak layers remain active. Use caution when pushing out into more complex terrain.
Confidence
Moderate - Uncertainty is due to the complexity of the snowpack’s structure.
Weather Forecast
Monday Night: Scattered cloud, alpine low -10, moderate northwest wind.
Tuesday: Cloudy with sunny periods and isolated flurries, alpine high -4, moderate southwest wind.
Wednesday: Cloudy with flurries, alpine high -4, moderate southwest wind increasing to strong overnight.
Thursday: Periods of snow accumulating 5-10 cm, alpine high -4, strong southwest wind easing to moderate.
Avalanche Summary
Natural storm slab activity has slowed down since the end of the storm. Explosive control work producing avalanches up to size 3 have been reported along the Highway 1 corridor. Within the last week, there have been a few reports of persistent slab avalanches failing on a layer of surface hoar (down 60-100 cm) at treeline elevations.
Snowpack Summary
20-40 cm of new snow from the latter part of last week has covered a layer of feathery surface hoar that has been found at all elevations. A thick layer of faceted crystals, previously wind-affected surfaces, and/or surface hoar in sheltered areas (around treeline and below) is now 40-80 cm below the surface.
An additional layer of surface hoar may be found in sheltered areas around treeline down 60-100 cm. In some areas this may sitting on a thin crust. A variety of crusts from late October are buried deeper in the snowpack.
Avalanche Problems
Persistent Slabs
There is a lot of uncertainty associated with the reactivity and distribution of a surface hoar/crust layer buried 70-110 cm. This layer is most likely found in sheltered openings around treeline and below.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1.5 - 2.5
Wind Slabs
Recent periods of moderate wind have begun to build wind slabs in the alpine. Keep an eye out for these areas of firmer snow as you transition into exposed alpine terrain.
Aspects: North, North East, East, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2