Kootenay Boundary

It's important to make conservative terrain choices even though the avalanche danger is slowly decreasing. The consequences of triggering a persistent slab remain high.

Fair - The weather pattern is stable

Synopsis: A strong ridge of high pressure should maintain dry conditions with possible valley cloud for at least the next few days. A slight temperature inversion should stick around through Saturday with mountaintop temperatures getting close to 0 degrees. A weak upper trough slides across the province on the weekend, but this might only result in a bit more mid-level cloud and a chance of flurries. By Sunday the inversion should disappear. Winds are light gusting to moderate from the W-NW throughout the period.

Most areas reported a fairly widespread and large natural avalanche cycle on Tuesday. Many of these slides stepped down to mid-December persistent weak layer and produced avalanches up to Size 3.5. There were also reports of skiers and machines triggering slab avalanches from a distance (remotely and sympathetically triggered). Most reported avalanches occurred above 1900-2000 m from a variety of aspects.

Warm temperatures and previous rain have probably created a surface crust on steep solar aspects and all slopes below around 1800 m. Dry powder can still be found at higher elevations. Around 30-60 cm of settling storm snow overlies a variety of old surfaces which include heavily wind-affected surfaces in exposed locations, faceted powder and buried surface hoar in sheltered terrain. Buried 80-100 cm deep, you'll likely find a touchy weak layer of surface hoar sitting on a thick rain crust. This widespread persistent weakness exists at all elevation bands, and continues to be the primary layer of concern for the region. With the recent load of storm snow, I expect this layer to remain active with the potential for large and destructive avalanches. At the base of the snowpack, a crust/facet combo appears to have gone dormant for the time being.