Avalanche Forecast

Moderate -

Sunday night: Mainly clear. Light north winds shifting northwest.Monday: A mix of sun and cloud, becoming increasingly cloudy. Light northwest winds. Alpine high temperatures around -13.Tuesday: Mainly cloudy with isolated flurries and a trace of new snow. Light southwest winds. Alpine high temperatures rising to -6 with a mild alpine temperature inversion.Wednesday: Cloudy with scattered flurries bringing up to 5 cm of new snow, continuing overnight. Alpine high temperatures around -2 or higher as freezing levels rise to 1500-2000 metres by Thursday morning.

Reports from Saturday show an active day for avalanches in the Columbias. A more notable MIN report describes a large (size 2) snowmobile remote (from a distance) triggered storm slab in the Clemina Creek area. (link here) Numerous other small (size 1-1.5) storm slabs were also triggered with ski cutting and skier traffic.Prior to the storm, the last reported persistent slab activity was last Sunday when a few large (size 3) persistent slab avalanches were observed on south facing alpine features. This was the final report from a widespread persistent slab avalanche cycle that was quite active last week, particularly in the Selkirks and the northern tip of the Monashees. Our recent storm loading and storm slab activity has failed to produce reports of avalanches stepping down to this layer, suggesting that it may finally have reached dormancy.Looking forward, expect a decrease in natural avalanche activity while the potential for human triggering sees a more gradual decline.

Saturday's storm brought about 30-40 cm of new snow to the region. Below the new snow interface, which appears for the most part to be free of any weak surface hoar crystals, 10 to 20 cm of older low density snow sits above old wind slabs in the alpine, and in some isolated areas above small surface hoar (feathery crystals). Avalanche activity on the 100-140 cm deep weak layer that formed during the dry spell in early December has greatly diminished over the last week. This layer is composed of weak facets, surface hoar, and a sun crust on steep south-facing slopes. It is believed to be trending toward a dormant state after the loading test brought by Saturday's storm failed to produce reports of any avalanches 'stepping down' to trigger it. Places that might still challenge this assumption of dormancy would be steep north and east facing slopes between 1900-2300 m and steep south-facing slopes in the alpine.The lower snowpack is generally strong and settled, with a crust that formed in late October near the bottom of the snowpack.