Avalanche forecast

Northwest Inland

Jan 26 – 27, 2016Avalanche Canada
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Avalanche danger

Thu
Fri
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

In the west of the region where recent accumulations were the greatest, new wind slabs are expected to be deeper and more reactive.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–3
    Continued strong winds and new snow have likely formed reactive wind slabs at treeline and in the alpine. New winds slabs are expected to be larger on the west side of the region where recent accumulations were the greatest.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–3
    New snow has been slowly accumulating over a layer of facets and surface hoar and may now be primed for triggering in some areas.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Warm, wet and windy conditions will persist for Wednesday and Wednesday night. Expect between 5-8mm of precipitation, extreme southerly winds and freezing levels at about 1700m. On Thursday, the region should see generally light flurries, strong southwest winds and freezing levels dropping to about 1200m. By Friday, a pattern shift should bring generally overcast skies, decreased winds and freezing levels closer to 600m.

Avalanche Summary

There are very few recent observations from the region. A couple natural size 2 slab avalanches were observed in wind-loaded terrain (N-NE aspects) at around 1800 m last Friday. Light to locally moderate amounts of new snow and extreme southwest winds likely sparked a new round of wind slab activity on Tuesday.

Snowpack Summary

On Monday night a few centimetres of new snow fell in the mountains around Smithers while closer to 15 cm fell in areas further west. Strong to extreme winds have likely redistributed much of this new snow into reactive wind slabs at higher elevations while lower elevation surfaces are likely now moist due to rising freezing levels during the system.  There is a notable persistent weakness of buried surface hoar in many places, generally found between 30 and 60 cm deep. Wind, sunshine, and milder temperatures could help promote slab development in the snow overlying this interface. Stay tuned to signs of instability like recent avalanches, whumpfing, and shooting cracks. The mid pack that was reported to be well settled may have now facetted in the shallower areas, and the deeper basal layers are almost certainly facetted and weak.

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