Avalanche forecast

Kootenay Boundary

Jan 15 – 16, 2015Avalanche Canada
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Avalanche danger

Sat
Sun
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Snowfall will be highly variable across the region.  Forecast danger ratings are for areas that receive greater accumulations

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2–5
    The forecast snow will fall on a layer of surface hoar above a widespread crust. In areas that receive the greater snowfall amounts this could result in touchy avalanche conditions especially in wind loaded terrain.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    3–6
    Wind slab avalanches may be able to trigger deeper weak layers. Persistent slabs may also be triggered by the weight of a person or snowmobile in specific areas such as thin spots or convexities in the slope.

Weather Forecast

Synopsis: A fast moving cold front will bring precipitation to the interior of the province through tonight and Friday with the next system forecast to arrive Saturday night.  Overnight and Friday:  5-20cm new snow with the highest amounts forecast for Kootenay Pass, winds will be moderate to strong from the southwesterly with freezing levels at 1000m.  Saturday: clearing briefly with light northwesterly winds becoming southwesterly and freezing levels at valley bottom.  Sunday: moderate to heavy snowfall  becoming rain at lower elevations with light westerly winds and freezing levels at 1500m.

Avalanche Summary

Avalanche activity has slowed in recent days, but the occasional avalanches that are being reported suggest that there is still the potential for human-triggering of large avalanches.  Recent avalanche reports have described large slides ranging from size 2.5 to 3 .  Several of these were remotely triggered by ski touring groups from distances as far as 100m away.

Snowpack Summary

The forecast snow will burry a layer of Large surface hoar crystals on the old snow surface. Underneath this a thin frozen crust can be found up to about 1900m on N aspects and to ridgeline on south aspects. Deeper in the snow pack our main concern continues to be another crust/surface hoar combo buried in mid-December. This weak layer can be found between 60-120cm down and still has the potential to be triggered by people to produce surprisingly large avalanches. Avalanche professionals in the region are  treating this interface with suspicion. Near the base of the snowpack the facet/crust layer has mostly been dormant, however, isolated recent activity in the Bonnington Range suggests it may still be reactive in isolated terrain.

Confidence

Good - Forecast snowfall amounts are uncertain

Regions covered