Regions
Kootenay Boundary.
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Weather Forecast
Little change in the overall pattern. Wednesday: Mostly clear skies, winds decreasing to light NW by lunch. No precipitation, freezing level rising to 1500m then returning to valley bottom. Thursday: Broken skies, light variable winds at all elevations, no significant precipitation, freezing level rising to 1400m then returning to valley bottom. Friday: Broken skies, light variable winds at all elevations, 1 to 2cm snow, freezing level rising to 1000m then returning to valley bottom.
Avalanche Summary
No new avalanche activity was reported on Monday.
Snowpack Summary
5 to 10 cm of snow that has seen some heat on solar aspects and faceting on cooler aspects rests on top of a widespread layer of surface hoar above a crust that extends all the way to ridge crest. This robust and supportive crust is effectively "capping" the snowpack keeping the weight of riders from interacting with any deeper weak layers. The mid-January surface hoar layer is down about 100cm in the alpine and down around 50 to 60cm at treeline. The mid-December crust/facet/surface hoar weakness may persist in the mid to lower snowpack at higher elevations. Both these layers have gone dormant for the time being, we would likely need significant warming to re-activate them.
Problems
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.