Bulletin d’avalanche

Kootenay Boundary

Mar 21 – 22, 2014Avalanche Canada
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Archivé · expiré 13 years ago

Danger d’avalanche

Sun
Mon
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
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Points saillants

Watch the temperature and solar warming this weekend, heat and/or direct sun could quickly initiate cornice fall and natural slab avalanche activity.

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–3
    Up to 35cm of new snow fell on Thursday adding to an existing storm slab which may be touchy in wind exposed terrain.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–3
    Watch for loose wet avalanches in steep, sun-exposed terrain. Loose wet avalanches can be pushy and entrain mass quickly.

  • Deep Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    3–5
    The deeply buried weak layers still show "sudden" results in snowpack tests. Triggers for large avalanches on these layers include cornice falls, solar warming, or hitting the wrong place in a thin snowpack area.

Confidence

Fair

Weather Forecast

Synopsis: A ridge builds into the interior this weekend making for a fairly unexciting weather weekend. Look for high cloud, moderate freezing levels and no significant precipitation.Saturday: Freezing Level: 500m - 1100m; Precipitation: Nil; Treeline Wind: Light, SE | Ridgetop Wind: Light, W/SWSunday: Freezing Level: 600m - 1400m; Precipitation: Nil; Treeline Wind: Light, SW | Ridgetop Wind: Light, W/NWMonday: Freezing Level: 1500m; Precipitation: Nil; Treeline Wind: Calm | Ridgetop Wind: Light, W

Avalanche Summary

On Thursday a widespread natural avalanche cycle to size 2.5, averaging size 1.5 was reported. Activity was most prevalent above 1800m on all aspects. It sounds like the majority of the action was on the March 17th crust. There were no reports of anything stepping down to the deeper buried weak layers.

Snowpack Summary

In general about 35cm of new snow fell on Thursday adding to an existing storm slab which formed last weekend. Wind data was scarce on Thursday, although I suspect the new snow exists as a wind slab in exposed lee terrain. Below the recent storm snow you may find weak surface hoar in shaded terrain and a crust on previously sun-exposed slopes. About 60cm below the surface you'll find a strong rain crust which exists on all aspects below 2000m. This crust is widespread in the south of the region where heavy rain fell on March 10. As you head north in the region where the mountains are higher and colder temperatures persisted, this crust is less likely to exist.A facet/crust persistent weakness buried at the beginning of February, now down 70 to 160cm, has been highly variable in terms of reactivity but still shows 'sudden' results in some snowpack tests. In areas where the strong and supportive near surface crust exists, triggering this layer has become unlikely. That said, this layer is still difficult to trust and any avalanche at these deeper, persistent interfaces would be large and destructive.,

Régions couvertes