Avalanche Forecast
Regions: South Columbia.
Confidence
Fair
Weather Forecast
Snowfall is expected to increase overnight and into Friday (5-10 cm by Friday afternoon). Winds are forecast to be moderate from the SW to NW. Freezing level at valley bottom. Snowfall becomes light on Saturday before a second pulse of snow arrives late on Sunday.
Avalanche Summary
Persistent slabs continue to be triggered by skiers, vehicles and remote triggers (from a distance away). These have been up to size 2.5 and failing 50-70 cm down on the mid-December crust/surface hoar layer. Many of these have been around treeline elevation, although some smaller sized avalanches were triggered as low as 1750 m. Several size 1-1.5 wind slabs also failed naturally or with skier triggers following strong northerly winds.
Snowpack Summary
New snow may hide wind slabs which formed recently in response to strong northerly winds. The primary concern is the persistent weak layer of mid-December surface hoar. Below 2100 m this surface hoar sits on a thick, solid crust and has been acting as a perfect sliding layer. Fractures have been propagating long distances and have allowed for remote triggering from adjacent terrain. A hard rain crust with facets from early November is buried more than a metre down and is currently unreactive. However, triggering from shallow rocky and unsupported terrain remains a concern.
Avalanche Problems
Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 2 - 5
Wind Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 4