Bulletin d’avalanche

Blues

Wallowa Avalanche Center
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Danger d’avalanche

Sun
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
3 · Marqué
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Périmé — ce bulletin a expiré 6 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Fast and long running dry loose avalanches will easily be triggered in terrain steeper than 35 degrees today.  If you trigger one of these avalanches, it could easily knock you around or push you into consequential terrain traps such as into a gully, over a cliff, or into bands of dense trees.   The new storm snow is sitting upon a thick rain crust/surface hoar combination that is now 2 feet from the surface.  This is a dangerous combination, and may lead to easily triggered avalanches.  With additional snow, wind, and settlement throughout the day- the storm snow may start to form more of a cohesive slab, likely becoming even more reactive. 

Problèmes avalancheux

  • Persistent Slabs

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

    The 6-8" of new storm snow that has fallen since Thursday has added weight to the upper snowpack that sits upon a Weak Snow/Crust sandwich from 1/12.  Surface Hoar (Hoar Frost) has been observed on this rain crust, and is a very dangerous combo.  This can be found 2 feet down and recent snowpack observations from forecasters have found reactive test results.  Use hand pits and small test slopes to test the reactiveness of this layer.  Avoid terrain steeper than 30 degrees if seeing red flags such as recent avalanche activity, collapsing of the snowpack, or shooting cracks in the new snow.  

  • Loose Dry

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

    This type of avalanche problem type is predictable.  Manage this problem through your terrain selection.  It will be found on all aspects and elevations in terrain approaching or exceeding 35 degrees.  If you trigger a dry loose avalanche in the wrong location (top of a cliff, above a gully, or in dense trees)- a rider could easily be injured, buried, or killed.   The light density storm snow provides excellent riding on lower angle slopes.  Utilize small, safe, but steep test slopes to test the reactiveness of the new snow.   

    These long running "sluffs" are going to be especially sensitive in the Blues today as they will start to dig down to the 1/12 Rain Crust that is now likely 1.5-2 feet deep.

Avalanche Discussion

Since Thursday, we have added 1" of Snow Water Equivelant to the snowpack.  Although it came in over some time- which normally allows the snowpack to adjust to this weight-  It is falling onto a dangerous combination of a thick rain crust with weak snow above.   Dial back your terrain selection to reflect the elevated avalanche hazard.  A likely scenario could be a person or machine triggering a large sluff that could easily step down into the weak snow sitting above the crust- resulting in a much larger avalanche.  

Régions couvertes