Triggering large avalanches remains possible, especially on wind loaded slopes.
Summary
Confidence
Moderate -
Weather Forecast
SUNDAY NIGHT: A weak front passes overnight bringing 3-10 cm of snow, strong to extreme wind from the southwest, alpine temperatures around -2 C.MONDAY: Light flurries, strong wind from the southwest, freezing level rising to 1700 m, alpine high temperatures around -5 C.TUESDAY: 5-20 cm of snow, extreme wind from the southwest, freezing level around 1700 m.WEDNESDAY: Scattered flurries with 4-8 cm of snow, strong wind from the southwest, freezing level around 1500 m.
Avalanche Summary
Explosive control produced numerous large (size 2-3) wind slab and deep persistent slab avalanches on Friday and Saturday, primarily on north and east aspects above 2000 m.Natural activity was also reported on Friday, primarily size 1-2 wind slab avalanches on east-facing lee terrain in the alpine. Some appear to have stepped down to the deep persistent weak layer near the bottom of the snowpack.
See some photos of these from north of Crowsnest Pass. On Thursday, the storm snow was also very reactive to skier and snowmobilie traffic, producing widespread cracking, whumpfing, and some small avalanches.
Snowpack Summary
Strong winds have affected all open terrain, scouring windward slopes and forming wind deposits on lee slopes. Currently only 30-120 cm of snow can be found in alpine areas and much less at lower elevations.Roughly 20-30 cm of recent snow has buried old wind slabs and sun crusts. The lower snowpack has a weak structure composed of facets and crust that has been reactive to heavy triggers. Terrain features like smooth alpine bowls with variable snowpack depths are suspect for human triggering.
shorton,
Avalanche Canada
