Avalanche forecast

Northwest Inland

Jan 29 – 30, 2016Avalanche Canada
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Avalanche danger

Sun
Mon
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

We're coming out of a dynamic weather pattern and snowpack observations have been extremely limited. Regional snowpack variably certainly exists. Make observations continually as you travel.

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. In some areas, recent rain may have destroyed the layer. In other areas, the overlying slab may be primed for human triggering.

Confidence

Low - Due to the number of field observations

Weather Forecast

On Saturday and Sunday expect generally overcast skies and isolated flurries. Freezing levels for the weekend should hover around 450m while ridgetop winds should be mainly light from the north. On Monday, the region may see 3-5cm of new snow. Winds on Monday may increase to moderate from the southwest while freezing levels should drop to valley bottom.

Avalanche Summary

There have been very few recent observations, although a report from the far west of the region indicated numerous avalanches to size 3 occurred in low elevation terrain in the far west of the region. These avalanches likely occurred on Tuesday or Wednesday and failed in response to rain and warming below treeline. With forecast cooling, this type of activity will surely taper-off. At higher elevations I'd still expect recently formed wind slabs to be sensitive to human triggering.

Snowpack Summary

Snowpack observations have been extremely limited from this region. Since Monday night generally light amounts of new snow fell in the mountains around Smithers while closer to 50 cm fell in areas further west. Strong winds have likely redistributed much of this new snow into reactive wind slabs at higher elevations. Rain fell below about 1200m. If cooling happens as forecast, surfaces at lower elevations will likely be sporting a hard crust. There is a notable persistent weakness of buried surface hoar in many places, generally found between 25 and 60 cm deep. Wind and milder temperatures may have helped to promote slab development in the snow overlying this interface. In other areas, rain may have destroyed the layer. Stay tuned to signs of instability like recent avalanches, whumpfing, and shooting cracks. The mid pack was reported to be well settled, although various levels of faceting can be certainly be expected in the lower snowpack.

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