Avalanche forecast

Kootenay Boundary

Dec 4 – 5, 2013Avalanche Canada
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Avalanche danger

Fri
Sat
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate

Highlights

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–4
    Northeast winds have created wind slabs at higher elevations. Wind slabs may have reverse loaded terrain features that were stripped by Westerly winds during the recent storm.
  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    2–5
    We expect the recent storm snow to continue to be reactive where it sits above surface hoar and crusts that were buried at the end of November.

Confidence

Fair - Due to the number of field observations

Weather Forecast

Mostly clear and cold for the forecast period. There is a chance of some cloud and very light flurries in the Southeast.

Avalanche Summary

No reports of natural avalanches releasing after the storm. Storm slab avalanches may continue to be triggered by light additional loads like skiing/riding. Storm slab avalanches that are released may be large and destructive. This storm needs some time to settle and bond, forecast cold temperatures may preserve recently buried weak layers and require more time to settle and bond than when the post storm temperatures are warm. This is a complex avalanche forecasting scenario; complicated by early season timing when we have few observations coming from the field.

Snowpack Summary

The new storm slab is about 40-70 cm deep depending on where you are in the region. Storm slabs are sitting above recently buried weak layers of surface hoar on North aspects and melt/freeze crusts on solar aspects. In some parts of the region, the storm slab may not be well consolidated and may not result in shears from snow-pit tests. There are some reports of a deeply buried early season crust that formed in October, this layer is more likely to be found in the high alpine on northerly aspects.

Regions covered