Bulletin d’avalanche

Northwest Inland

Mar 27 – 28, 2013Avalanche Canada
Voir sur la carte
Archivé · expiré 14 years ago

Danger d’avalanche

Fri
Sat
Alpin
3 · Marqué
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
Ouvrir la carte complète

Points saillants

Be aware of changing conditions with daytime warming and sunny skies. Watch solar slopes and overhead hazards.

Problèmes avalancheux

  • Cornices

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible - Likely
    Taille
    1–6
    Large developed cornices loom over slopes. Failure may initiate large avalanches failing on the March 09 persistent weak layer. Cornices will likely become weak if the sun is shining. Wind slabs may be found on lee slopes and behind terrain features.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–7
    A 30 - 60cm slab sits on the March 09 surface hoar/crust combo. The distribution of this layer seems to be variable. However if triggered, a large destructive avalanche may occur with consequences. Remote triggering from afar is possible

  • Loose Wet

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

Confidence

Fair - Due to limited field observations

Weather Forecast

Continued sunny skies and spring-like conditions will persist through to Friday. The next low pressure system is expected to arrive later Sunday night. Thursday: Sunny skies. Alpine temperatures -1.0 and freezing levels 1500 m. Ridgetop winds blowing light from the West. Friday/Saturday: Sunny skies, partial cloud later on Saturday. Alpine temperatures -1.0/ -4.0 and freezing levels 1300 m. Ridgetop winds blowing light from the West. 

Avalanche Summary

Numerous loose wet avalanches from steeper solar aspects up to size 2.0.

Snowpack Summary

Cornices have become well-developed and could easily become unstable during periods of warm weather or direct solar radiation. Most snow surfaces exist on solar aspects up to 2300 m, forming a melt-freeze crust overnight.Northern areas of the region have experienced strong winds that have redistributed storm snow on lee aspects creating stiff wind slabs. 35 - 65 cm of recent snow sits on a variety of old snow surfaces, including crusts, previous wind slabs and a buried surface hoar layer (March 9th). Last week, the March 9th surface hoar layer has been touchy in many areas and many large avalanches have released on it. Currently, this layer seems to be less reactive, but is still a concern (low probability-high consequence) . Recent snowpack tests are showing hard, resistent shears. This layer may be healing in some places, but I would remain conservative and continue to dig and test before diving into my line. The distribution of the surface hoar is variable and it may not exist, or be reactive, in every drainage. Where it does exist, it appears to be present at all elevations.

Régions couvertes