Avalanche forecast

Northwest Coastal

Mar 20 – 21, 2012Avalanche Canada
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Avalanche danger

Thu
Fri
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
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Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1–4
    New wind slabs may form in exposed lee and cross-loaded terrain.

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–6
    Cornices are reported to be very large and potentially unstable at this time. A cornice fall could be destructive by itself, and may also act as a trigger on the slope below.

Confidence

Fair - Forecast snowfall amounts are uncertain

Weather Forecast

Wednesday: Light convective snowfall - 5-15cm. The freezing level rises to 400-500m during the day. Winds are moderate from the SW. Thursday: Isolated flurries with possible sunny breaks in the afternoon. Freezing level rising to 600m. Winds are light from the SE. Friday: A mix of sun and cloud. Freezing level rising to 600-800m during the day.

Avalanche Summary

There has been very little recent avalanche activity aside from a few cornice failures, most of which did not trigger a slab below. Expect to find small pockets of wind slab in steep exposed terrain that could be triggered.

Snowpack Summary

5-15cm of new snow sits on the previous snow surface which included a sun crust on southerly aspects, surface facets or surface hoar in cool shady areas, and pockets of wind slab in exposed terrain. A variety of potential weak layers exist between 60 and 120cm deep. These include surface hoar or facets. There has been no recent activity on these layers but they could wake up with heavy triggers like a large cornice chunk or a snowmobile digging its track in. Cornices in the region are reported to be very large and potentially unstable.

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