Bulletin d’avalanche

Kootenay Boundary

Feb 7 – 8, 2020Avalanche Canada
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Archivé · expiré 7 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

Increasing westerly wind during the day might form fresh wind slabs sensitive to human triggering. A new snow storm is forecast to arrive in the late afternoon with strong wind from the southwest and increasing snowfall at the end of the day.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–1.5

    Wind has recently switched direction from northwest to southwest and back again. Westerly wind will increase in the afternoon and switch to southwest. At treeline elevations, wind slabs may overly a crust which may make for a favorable sliding surface.

    The west of the region received the highest snowfall amounts in the last days. Soft slab avalanches within the storm snow were observed in that area and might still be sensitive to human triggers.

Confidence

Moderate - Uncertainty is due to the timing of the incoming weather system.

Weather Forecast

Thursday Night: Flurries, accumulation up to 5 cm, light to moderate northwest wind, alpine high -5 C, freezing level 800 m.

Friday: Cloudy with flurries and sunny breaks, accumulation 5-10 cm, light to moderate westerly wind, alpine high -5 C, freezing level 1000 m.

Saturday: Snow, accumulation 10-20 cm, moderate to strong southwest wind, alpine high -3 C, freezing level 1100 m.

Sunday: Mix of sun and cloud, moderate northwest wind, alpine high -9 C, freezing level 800 m.

Avalanche Summary

On Wednesday several small (size 1) slab avalanches in the alpine were triggered by skiers. Several small (size 1) natural and skier triggered loose dry avalanches were reported in steep terrain at treeline and in the alpine. 

Snowpack Summary

Wind switching directions has redistributed recent new snow onto a variety of aspects. The recent storm snow seems to bond well with the crusts below. As high as 2000 m, the upper snowpack contains a series of crusts from recent warming and rain events.

A layer of surface hoar is buried 100-150 cm below the surface in sheltered areas around treeline but has not been associated with avalanche activity recently. Weak facet/crust layers near the base of the snowpack are particularly noteworthy in the western Boundary area.

Terrain and Travel

  • Be alert to conditions that change with elevation.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Watch your sluff: it may run faster and further than you expect.

Régions couvertes