Bulletin d’avalanche

Northwest Inland

Mar 29 – 30, 2013Avalanche Canada
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Archivé · expiré 14 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

Be alert to conditions that change with daytime warming. Danger ratings may exceed posted levels when solar radiation is strong.

Problèmes avalancheux

  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–6
    Large cornices will likely become weak if the sun is shining. Cornice failures may be destructive by themselves and may also initiate avalanches on the slope below.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely - Possible
    Taille
    2–5
    Spotty surface hoar buried on March 9th may be reactive in some drainages. Dig down and test layers before committing to big lines. Deep weakness that formed early season may also resurface as an issue with forecast warming.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely - Very Likely
    Taille
    1–4
    Clear sunny skies and warmer afternoon temperatures will promote deterioration within the upper snowpack. If surface snow becomes moist or wet, loose wet avalanches are likely.

Weather Forecast

No precipitation is expected for the forecast period. Although high cloud is forecast on Saturday, generally clear skies are expected on Sunday and Monday.Winds will be light from the west on Saturday, generally calm on Sunday, then switching to light and southwesterly Monday.Freezing levels will hover at about 1300m on Saturday, 2400m on Sunday and then 1900m on Monday.

Avalanche Summary

Numerous loose wet avalanches have occurred from steeper solar aspects up to size 2.0. Size 2 cornice releases have also been noted. A size 2 natural was also reported in Morning Bowl in the Hankin area. It reportedly failed down to rocks in shallow places on a convex roll. I would expect more of this activity with forecast warming.

Confidence

Fair - Due to variable snowpack conditions

Snowpack Summary

Surface snow has settled with the influence of warm temperatures and surface hoar is growing on shaded slopes. Solar aspects and lower elevation terrain are now well into a daily melt-freeze cycle. 30 - 60 cm of snow overlies a crust, old wind slabs or surface hoar layer buried on March 9th. Reports suggest this layer is less reactive, but may still be a concern in some areas. The distribution of the surface hoar is also highly variable and it may not exist in every drainage. I would still remain conservative and continue to dig and test before diving into my line. Deeper in the snowpack, basal facets may resurface as a concern with forecast warming.Cornices have become well-developed and could easily become unstable during periods of warm weather or direct solar radiation.

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