Avalanche forecast

Northwest Coastal

Apr 6 – 7, 2013Avalanche Canada
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Archived · expired 13 years ago

Avalanche danger

Mon
Tue
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–3
    New winds slabs may form in exposed lee terrain and cross-loaded features. Triggering may be possible in steep terrain.

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–6
    Large developed cornices loom over slopes. A cornice fall has the potential to initiate large avalanches.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    1–5
    Recent reports of remote triggering suggest the March 9th surface hoar layer is still touchy in some areas. Where it is still reactive, avalanches can be large and potentially destructive.

Confidence

Fair - Freezing levels are uncertain on Sunday

Weather Forecast

Overnight and Sunday: Moderate precipitation is expected to continue this evening, becoming light convective showers by morning. Temperatures should cool down a few degrees as the precipitation ends.Monday: A ridge of High pressure is expected to start to dry up the region on Monday. There is a chance that a low pressure system that is tracking South of the U.S. border may alter its course and cause enhanced precipitation for the Southeast regions.Tuesday: High pressure is expected to bring mostly clear skies and light winds during the day.

Avalanche Summary

No new reports of avalanches.

Snowpack Summary

10-15 cm of new snow sits on a variety of old snow surfaces including a melt-freeze crust, moist snow, sugary facets, and wind affected snow. Pockets of wind slab could develop in exposed lee terrain over the next several days. Between 50-75cm below the surface is layer of surface hoar buried on March 9th which is variably reactive. In some areas it is stubborn and requires a significant trigger. In other areas the layer is still well preserved showing sudden planar or sudden collapse test results, and remains a primary concern among some professional operators.The mid snowpack is generally well settled and strong. Having said that, basal facets may resurface as a concern with spring warming, particularly in the north of the region. Cornices are large and untrustworthy.

Regions covered