New snow has pushed the snowpack past it's tipping point, leaving it primed for human triggering. Conservative terrain choices are recommended.
Summary
Confidence
Moderate -
Weather Forecast
TUESDAY NIGHT: Lingering flurries could produce another 5cm of snow, strong wind from the west, freezing level dropping to 1100m, alpine temperatures drop to -8c. WEDNESDAY: Mix of sun and cloud with isolated flurries, strong wind from the west, freezing level up to 1400m, alpine high temperatures around -5c. THURSDAY: Increasing cloud with stormy weather starting in the evening, moderate wind from the west increasing throughout the day, freezing level climbs to 1500 m throughout the day, alpine high temperature around -5c. FRIDAY: 5-10cm of snow by the morning then cooling and clearing throughout the day, moderate to strong wind from the northwest, freezing level drops to valley bottom, alpine high temperatures around -10c.
Avalanche Summary
Widespread natural activity was observed around Elkford and Sparwood on Tuesday. Many avalanches failed on deep persistent weak layers in the alpine.Snowmobiles remotely triggered several small avalanches on cutbanks north of Sparwood. Although these avalanches were small, they involved the entire depth snowpack and failed weak layers at the bottom of the snowpack.
See this MIN report. Deep persistent slabs were also reactive over the past few days. On Monday, a skier triggered a large slab avalanche (size 2) on a east aspect around 1800 m. The avalanche failed on a persistent weak layer 40 cm below the surface. On Friday and Saturday, explosive control produced numerous large (size 2-3) wind slab and deep persistent slab avalanches on north and east aspects above 2000 m.
Snowpack Summary
Tuesday's storm hit the region with 20-40 cm of new snow, forming fresh storm slabs at upper elevations. This substantially increases snowpack depths throughout the region, which prior to the storm range from 30-120 cm in the alpine and much less at lower elevations.The lower snowpack has a weak structure composed of facets and crusts, and the additional load of the new snow has pushed these weak layers past the tipping point. Any avalanche could step down to the bottom of the snowpack.
shorton,
Avalanche Canada
