Bulletin d’avalanche

Northwest Coastal

Feb 13 – 14, 2014Avalanche Canada
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Archivé · expiré 13 years ago

Danger d’avalanche

Sat
Sun
Alpin
4 · Fort
Limite forestière
3 · Marqué
Sous la limite
3 · Marqué
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Points saillants

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely - Very Likely
    Taille
    1–4
    A very touchy and destructive storm slab sits over weak surfaces which formed during the long cold snap. More snow in the forecast will add to the size and reactivity of the avalanche problem. Conservative terrain selection is now critical.

Confidence

Fair - Intensity of incoming weather systems is uncertain on Friday

Weather Forecast

Friday: Continued moderate snowfall / Strong southwest winds / Freezing level at 500mSaturday: Light snowfall becoming moderate to heavy overnight / Strong southwest winds / Freezing level at 800mSunday: Light snowfall / Strong southwest winds / Freezing level at surface

Avalanche Summary

Numerous size 2 natural storm slab avalanches were observed on Wednesday. As well, a few size 2.5 storm slab avalanches were remotely triggered from up to 200m away. This speaks to the highly touchy nature of the current instability. Due to the nature of the buried weak interface and forecast weather, ongoing destructive storm slab activity will continue.

Snowpack Summary

In many areas over 60cm of recent snowfall overlies a medley of old surfaces which include: weak surface facets, surface hoar, a scoured crust, or any combination thereof. Reports from the field indicate a very poor bond between the new snow and these old surfaces with accounts of whumphing and easy, sudden planar snowpack tests. Strong winds and slight warming have added cohesion to the new storm slab, and have shifted the new snow into deeper, destructive wind slabs in exposed terrain. The mid and lower snowpack are generally strong and well-settled. Basal facets and depth hoar are likely to exist in some parts of the region, but triggering has become unlikely.

Régions couvertes