Avalanche forecast

Northwest Coastal

Apr 6 – 7, 2015Avalanche Canada
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Avalanche danger

Wed
Thu
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
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Highlights

The forecast hazard may go higher on specific terrain features, especially in the afternoon with daytime heating

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–4
    The slab above the March 25th layer is still on the radar and should be treated with caution. It might be triggered by a small wind slab, or a loose wet avalanche on a solar aspect

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–4
    Clear warm days may present a hazard on sun exposed slopes. Small avalanches may produce enough force to trigger deeply buried weak layers and produce large destructive avalanches.

Confidence

Fair - Timing or intensity of solar radiation is uncertain

Weather Forecast

Clear and sunny for the next few days with the next Pacific frontal system forecast to arrive on the coast late Wednesday. Freezing levels will rise with daytime heating to 1300m and drop overnight to near valley bottoms.  Winds should be mostly light from the south

Avalanche Summary

Several large natural avalanches have been reported recently, with one of them being a cornice failure. Solar aspects are becoming active with daytime warming and producing point releases that grow up to size 2, and in one case triggered a slab on a weak layers to size 2.5

Snowpack Summary

Recent storm snow varies across the forecast area, with the biggest accumulations near the coast. With warm temperatures the storm snow is bonding to the variety of old snow surfaces including a layer of surface hoar and facets buried on March 25th. This weakness, now down approximately 40 to 60cm has the potential for propagating over large areas. The problems seems more touchy in the northern part of the region, but has been reported throughout the northwest coastal area. Weaknesses have also been found within the recent storm snow with tests producing easy to moderate sudden results in the top 20 to 40cm. The early March facet/crust persistent weakness is now down over a metre and produces hard, sudden planar results in snowpack tests.

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