Bulletin d’avalanche

Lizard-Flathead

Jan 8, 2017Avalanche Canada
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Archivé · expiré 10 years ago

Danger d’avalanche

Sun
Mon
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Points saillants

Our wind slabs are becoming less reactive but can't be totally trusted. Keep a healthy respect in suspect areas where wind loading has occurred.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    1–2
    Recent strong winds have created wind slabs on a wide range of aspects. Analyze each slope for patterns of wind loading and be especially cautious of thin trigger points. A small wind slab avalanche can trigger deeper weaknesses.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–3
    Where denser snow overlies weak, sugary snow, there is the potential to trigger large, dangerous avalanches. Dig down and test for weak layers before committing to any steep slope.

Confidence

High -

Weather Forecast

Sunday: Mainly cloudy with scattered flurries and 5cm of new snow. Winds light from the southeast. Alpine temperatures to -9, with a possible inversion increasing temperatures to -4.Monday: Flurries delivering 5-10cm of new snow. Winds light gusting to strong from the southwest. Alpine temperatures to -5.Tuesday: Cloudy with sunny periods and isolated flurries bringing a trace of new snow. Winds light to moderate from the west. Alpine temperatures to -14.

Avalanche Summary

A spooky size 3 natural avalanche was spotted in the Liverwurst bowl on a north aspect at 1800m on Friday. See the MIN report for details and an image that will help to keep deep persistent weaknesses on your mind. The crown is approximately 150cms high and the failure may have been on basal facets, which are large, sugary, and weak.

Snowpack Summary

A trace of new snow over Thursday night has covered a variable snow surface that includes wind slabs as well as sastrugi and hard slabs. Surface hoar up to 20mm was reported to be growing on the surface in some areas before the light snowfall. The aforementioned wind slabs formed in the alpine after recent arctic outbreak winds scoured snow from a wide range of aspects, forming touchy deposits on the lee side of exposed features. These wind slabs sit on a variety of older wind-affected surfaces at treeline and in the alpine and have given easy test results in the top 15-20cms of the snowpack and remain the primary stability concern in our snowpack. Deeper in the snowpack, the mid-December persistent layer (facet interface) has been more prominent and reactive in the Corbin zone than closer to Fernie. Take extra caution in thinner snowpack areas and areas of crossloaded snow where a smaller wind slab avalanche could step down to trigger this layer.

Régions couvertes