Avalanche forecast

Kootenay Boundary

Dec 9 – 10, 2019Avalanche Canada
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Avalanche danger

Wed
Thu
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low

Highlights

Triggering storm slab avalanches is possible. Watch out for signs of instability as you approach avalanche terrain.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    Triggering storm slab avalanches is possible, especially in steep and convex terrain and near ridgetops that have been loaded by blowing snow during the recent storm.

Confidence

Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength. Uncertainty is due to the complexity of the snowpack’s structure.

Weather Forecast

SUNDAY NIGHT: Cloudy with clear periods, 30 km/h wind from northwest, alpine temperatures around -6 C, freezing level lowering to valley bottom.

MONDAY: Mainly sunny, 30 km/h wind from the northwest, alpine high temperatures around -5 C, freezing level at 900 m.

TUESDAY: Cloudy, light wind from the southwest, alpine high temperatures around -3 C, freezing level at 900 m.

WEDNESDAY: Cloudy with some flurries, light wind from the west, alpine high temperatures around -5 C, freezing level at 900 m. 

Avalanche Summary

A few skier triggered avalanches of size 1 and one size 2 were observed on Saturday and Sunday. Two artificially controlled avalanches of size 1.5 and size 2 were reported on Saturday. The slabs were up to 50 cm thick, occurred on all aspects and released on a crust.

Several small (size 1) human triggered slab avalanches were reported on Tuesday and Wednesday. These slabs were between 10 to 30 cm thick and occurred on all aspects.

Snowpack Summary

The past week delivered about 15-45 cm of snow, with the highest accumulations around Kootenay Pass. This snow has been blown around by southwest wind and sits above hard layers of wind pressed snow and crusts. There are reports of several layers 30-70 cm below the surface that could develop into avalanche problems in the future. These layers could be composed of facet/crust layers or surface hoar depending on aspect and elevation. Several notable snowpack test results were reported on these layers as well as a few avalanches. Snowpack depths are about 120 cm at treeline and below treeline is just reaching threshold depths.

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