North Columbia

Maintain caution around wind slabs at higher elevations. Slabs in steep terrain and on unsupported slopes are likely to remain reactive to human triggering.

Moderate -

Sunday: Mainly cloudy with isolated flurries and a trace of new snow. Winds light from the southwest. Alpine temperatures to -7.Monday: Cloudy with scattered flurries and a possible 5-10 cm of new snow. Winds moderate from the south. Freezing level rising to 1000 metres and alpine temperatures to -5Tuesday: Heavy snowfall with 20-40 cm of accumulation. Winds moderate to strong from the south. Freezing levels rising to 1400 metres with alpine temperatures of 0.

Wind slabs have remained reactive to human and natural triggers over the past week. Friday's reports included natural and ski cut Size 1-1.5 wind slabs releasing from steeper convex features in north to northeast-facing terrain at treeline and above. On Thursday, numerous skier-triggered wind slabs in the size 1-2 range were triggered on a wide range of aspects at treeline. Natural size 1.5-2 wind slabs were also observed in alpine terrain. Wind slabs will likely remain reactive over the short term. In shallow areas like Clemina Creek, it could be possible to trigger a layer of facets buried around 60 cm below the surface.

Cold and clear weather has promoted both faceting of surface snow as well as the growth of surface hoar that has been reported to be up to 10mm in size in protected areas. Below this surface, our recent new snow was shifted first by southwesterly winds and then by northerly winds. As a result, wind slabs exist on a variety of aspects at upper elevations. These accumulations have covered old, thicker wind slabs from previous wind events. A layer of faceted "sugar snow" and spotty surface hoar which formed during December's cold snap now lies roughly 1 metre below the surface. This layer is now dormant in many areas, but may still be a concern in shallow snowpack parts of the region, particularly around Clemina Creek. I'd continue to investigate this layer before committing to any large, unsupported features. The lower snowpack seems to be generally strong and well settled.