Avalanche forecast

Northwest Inland

Mar 9, 2017Avalanche Canada
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Avalanche danger

Thu
Fri
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Several days of cold benign weather ahead. Concerns include wind slabs at higher elevations and the ongoing potential to trigger deep persistent slabs in shallow snowpack areas.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–3
    Gusty southwest winds at upper elevations have formed fresh wind slabs on leeward slopes and behind terrain features.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–3
    A lingering weakness at the bottom of the snowpack may remain sensitive to human triggering, especially in shallow snowpack areas. Smaller avalanches in motion also have the potential to step down and trigger deep persistent slabs.

Confidence

Low - Due to the number of field observations

Weather Forecast

Expect a mix of sun and cloud for the forecast period. Ridgetop winds should remain generally light to moderate from the east with alpine temperatures sitting at about -20.

Avalanche Summary

No new avalanches have been reported in the past few days.

Snowpack Summary

Generally light accumulations of low density snow have occurred in recent days. In some areas wind effect at higher elevations has resulted in wind slabs on east and north aspects. About 25cm below the surface, you may find a variety of old snow surfaces including stiff wind slabs, facets, crusts and surface hoar. The new snow may have a poor bond to these interfaces, especially in places where the slab is stiffer and more cohesive due to winds. At treeline, the average snowpack depths are 120-190 cm and a well consolidated mid-pack of approximately up to 100 cm sits above weak basal facets (sugary snow) near the ground. Recent snowpack testing has shown sudden easy results down 25 cm on a surface hoar layer and sudden hard results down 100 cm within the faceted snow.The deeper basal weakness remain a concern, especially in thin rocky start zones and shallow snowpack locations.

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