Bulletin d’avalanche

Newberry

Central Oregon Avalanche Center
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Danger d’avalanche

Mon
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
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Périmé — ce bulletin a expiré 6 months ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

A buried layer of weak snow will make large slab avalanches possible in the Newberry zone on sheltered, shaded slopes. Additionally, strong south winds have transported recent storm snow onto leeward slopes. This will result in avalanches also being possible below ridgelines and on the margins of the lava flow where these wind drifts exist.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2

    In the Newberry zone, we have been finding a buried persistent weak layer of faceted snow on shaded, sheltered slopes. In the locations where we have more recently dug, it appears this layer is trending towards stabilizing. That being said, the poor structure of the snowpack still exists. I would expect that in isolated areas this layer will be more reactive to triggering. This PWL has been observed to be 1 to 1.5 feet beneath the snow surface, buried under the storm snow we received over the last couple of weeks. Persistant slab problems warrant conservative decision making when in pertinent terrain. I would recommend all riders avoid steep and unsupported slopes on these sheltered north aspects. 

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2

    Sustained cold temperatures and up to 1.5' of recent storm snow have resulted in ample snow available for wind transport. On Saturday, I observed snow blowing from the south off of ridges and depositing on to leeward slopes. With increased winds forecasted through Sunday, I would expect continued wind loading, with suspect trigger points being beneath leeward ridgelines, cornices, and convex rollovers. Look out for red flags such as shooting cracks and collapsing of the snow to understand where this problem exists. Smooth, pillowy and rippled snow surfaces are also a good indication of wind slab presence. If in doubt of the snow stability, seek more windward terrain or slopes less than 30 degrees.

Régions couvertes