North Columbia

Stability is on an improving trend for Wednesday but the conditions still require conservative terrain selection. Wind exposed areas are the most concerning.

Moderate - Forecast snowfall amounts are uncertain on Thursday

Wednesday: A mix of sun and cloud. Winds light from the south. Alpine temperatures of -12. Thursday: Periods of snow delivering 15-25 cm of new snow. Winds moderate to strong from the south. Freezing level rising to around 1000 metres with alpine temperatures of -3.Friday: Flurries bringing another 5-10 cm of new snow. Winds strong from the southwest. Freezing level to around 800 metres with alpine temperatures of -5.

Reports from Monday are a continuation of what we've seen over Saturday and Sunday, with ample observations of storm slabs running both naturally and with ski cutting, generally from Size 1-1.5. A couple of natural Size 2.5 slides were observed in Glacier National Park while Saturday and Sunday saw a small number of remote triggers and slides stepping down to involve old wind slabs. Most avalanches have been described as very soft slab and several have been noted running fast and entraining large amounts of loose snow. A mid-storm interface observed at approximately half the depth of the new snow was particularly reactive over the past few days.As for Wednesday's outlook, fresh storm slabs should be expected to remain sensitive to skier and rider triggers, especially where they overlie weak layers present at our previous surface and where winds have promoted slab formation.

While the northern tip of the region has received very little from the recent stormy weather, most of the region saw around 25-40cm of new, low-density snow burying a range of surface conditions that developed last week. These previous surfaces include older wind slabs on a wide range of aspects, sun crust on steep solar aspects, faceted snow, as well as surface hoar found on sheltered open slopes in the days before the storm. The new snow is beginning to form a bond to these surfaces, but touchy conditions at this interface as well as at mid-storm interfaces should still be expected over the short term. Recent reports identify buried sun crust as a particular problem. A persistent weakness buried mid January is now down 50-80 cm and consists of buried surface hoar in sheltered areas, and/or widespread faceted old snow. It has generally stabilized but may be sensitive to triggering in isolated areas where buried surface hoar is preserved. Another surface hoar/facet persistent weakness that was buried mid-December can now be found down roughly 110-130 cm. While activity at this layer has declined, professionals in the north of the region are still treating it with caution.