Bulletin d’avalanche

Northwest Inland

Jan 27 – 28, 2016Avalanche Canada
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Archivé · expiré 11 years ago

Danger d’avalanche

Fri
Sat
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
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Points saillants

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

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    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

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    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

Up to 15mm of precipitation is forecast for Wednesday night with another 3-5cm of snow expected on Thursday. Ridgetop winds will remain extreme from the southwest while freezing levels will drop throughout the day from 1600m to about 1000m. On Friday and Saturday the region will see light flurries, significantly decreased winds and freezing levels around 700m.

Avalanche Summary

There are very few recent observations from the region. Light to locally moderate amounts of new snow and extreme southwest winds likely sparked a new round of wind slab activity. Rain may have also promoted loose wet avalanche activity at treeline and below.

Snowpack Summary

Since Monday night light amounts of new snow fell in the mountains around Smithers while closer to 25 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 surfaces at treeline and below 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 70 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 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.

Régions couvertes