Avalanche forecast

Kootenay Boundary

Feb 17, 2019Avalanche Canada
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Archived · expired 8 years ago

Avalanche danger

Mon
Tue
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

A cautious approach to backcountry travel is recommended as we come out of a period of active avalanche activity.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2
    Wind slabs can be found on a variety of aspects and all elevations.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1.5–2.5
    Two buried surface hoar layers are in the upper meter of the snowpack and may still be reactive to human triggering. The layers are most prominent at treeline and below.

Confidence

Moderate - Wind effect is extremely variable

Weather Forecast

SATURDAY NIGHT: Light flurries of low density snow with accumulations of 2-8 cm, light northeast wind, alpine temperatures drop to -15 C.SUNDAY: More spotty flurries of low density snow into the afternoon, accumulations up to 5 cm, light north wind, alpine temperatures around -15 C.MONDAY: Mix of sun and cloud, moderate northwest wind, alpine high temperatures around -15 C.TUESDAY: Cloudy with isolated flurries and trace accumulations, wind, alpine high temperatures around -15 C.

Avalanche Summary

Avalanche activity began to quite down on Saturday after four strait days of widespread storm slab and wind slab activity.On Friday, skiers triggered numerous size 1-1.5 storm slab avalanches and loose dry avalanches on all aspects in steep terrain (see this MIN report for an example here). On Thursday, strong wind formed fresh wind slabs that produced several size 1-2 natural avalanches. The wind slabs were very reactive to human triggering on all aspects. Two large (size 2) skier-triggered slab avalanches were reported at treeline elevations with crowns up to 80 cm thick.

Snowpack Summary

A total of 30 to 50 cm of snow has fallen over the past few days. The snow remains low density in some sheltered areas, but was dramatically affected by a wind event on Thursday that left hard wind slabs in exposed terrain. The new sits on a variety of old surfaces that include a sun crust on southerly aspects, variable wind-affected snow, and weak feathery surface hoar crystals at and below treeline. The snowpack hosts two buried surface hoar layers. The February 1st surface hoar is down 40 to 60 cm and has been recently reactive to human triggers. The mid-January surface hoar is 60 to 100 cm below the surface. This deeper layer of surface hoar is most prevalent below treeline on shady aspects, but it does not seem to be a widespread problem in the region. Below that, the snowpack is well settled.

Regions covered