Avalanche forecast

Northwest Coastal

Nov 30 – Dec 1, 2011Avalanche Canada
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Avalanche danger

Fri
Sat
Alpine
4 · High
Treeline
3 · Considerable
Below
3 · Considerable
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Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    2–5
    Expect to find deep and dense wind slabs in exposed terrain well below ridge crests.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2–5
    Recent storms have dumped well over 100cm in the past few days with more snow expected on Thursday. Storm snow instabilities may be triggered by a skier or snowmobile, or by additional loading from snow or wind.

Confidence

Fair - Due to limited field observations

Weather Forecast

A frontal system will spread light to moderate snowfall and strong SW winds on Thursday. Expect 20-30cm in coastal areas and 10-15cm near Terrace. The freezing level should be around 1000m. Conditions dry out and cool on Friday and Saturday under a NW flow. The freezing level should remain at valley bottom and upper level winds are moderate from the NW.

Avalanche Summary

Observations from Bear Pass include several natural avalanches up to Size 2.5, primarily in response to rising westerly winds on Tuesday. There are no new observations from other areas but I suspect natural avalanche activity continued on Tuesday as another storm dumped 30-50cm of new snow.

Snowpack Summary

Coastal areas are reporting a very deep and strong snowpack (+4m in some areas). Isolated wind slabs and lingering storm snow instabilities are likely over the next couple days. A buried surface hoar layer may be found down 100-150cm near Terrace, but there is no recent information on the presence and sensitivity of this layer.

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