Bollettino valanghe

Central Cascades

Central Oregon Avalanche Center
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Pericolo valanghe

Sun
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
3 · Marcato
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In sintesi

We are in the midst of a major storm pattern and avalanche danger is elevated at all elevations. Triggering avalanches will be likely on terrain features that have accumulated wind drifted snow near treeline and above treeline. Triggering avalanches in recent storm snow will be likely anwhere the wind has not stripped snow away. Avalanches have the potential to be large. Recognize where terrain traps such as rocks, trees, cliffs, and constricted features are in relation to where you are travelling; this type of terrain can greatly increase the consequence of getting caught in an avalanche. If you are unsure about the stability of the snowpack, stick to lower angle slopes less than 30 degrees steep to minimize your exposure to avalanches. 

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2.5

    Wind slabs have the potential to be larger than normal. The winds will be cranking at times and will be moving a lot of snow. We may see wind slabs in unusual places and farther down slopes than what we typically see. Wind slabs are most sensitive to triggering when they are fresh.

    Steep and convex terrain at and below ridge tops are the suspect places to trigger a wind slab but be cautious on any terrain feature that has accumulated blowing snow. As wind moves snow across open slopes, gully features in particular can become 'cross loaded' and filled in with new wind slabs.

    Cracking in the wind deposited snow and recent avalanches are good indicators that you can trigger an avalanche, but remember we don't always get that feedback even when unstable snow exists. Wind slabs can be avoided by sticking to sheltered areas or slopes that have been scoured by the wind. 

    Use carefull evaluation in areas of sparse trees, clearings, and sections of dead forests. Open areas 'below treeline' can get enough blowing snow to create wind slabs.

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2

    The high side of the snow forecast calls for 2 ft  of new snow by end of day Saturday. The low end is still calling for significant accumulation. That much rapid snowfall combined with temperatures rising during the day is the classic setup for storm slab avalanches. This will be a good day to steer around steep, convex, and unsupported terrain features. These are the places where you are more likely to trigger a storm slab avalanche. Utilizing small steep test slopes to check for cracking or small slabs releasing is a good way to check on reactivity of the storm slab. Avoiding slopes with obvious terrain traps such steep constrictions or runouts into trees and rocks will be a good strategy. 

Avalanche Discussion

Blowing snow will be prevalent at ridge tops and cornices have the chance to grow out over lee slopes. New cornices are very fragile and easily broken. Avoid stepping out onto a cornice and breaking through to the slope below. 

Regioni coperte