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
2 · Moderato
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Non aggiornato — questo bollettino è scaduto 2 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Triggering avalanches in wind deposited snow will be likely and avalanches can be large. Triggering loose snow avalanches in the new storm snow will  be possible in areas where the wind has not scoured it away. Use terrain to your advantage, if you have uncertainty in the stability of the snowpack stick to slopes less than 30 degrees steep. 

Problemi valanghivi

  • Wind Slabs

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

    The incoming snow will be cold, light, and easily moved by the wind. The wind on Friday had a lot of variability in speed. Some areas experienced light winds while the wind was cranking in other areas. The weather forecast has wind speeds in the sustained 25 mph range and wind slabs will continue to build in some areas. 

    The bulk of the wind slab problem will be above treeline and near treeline but continue to look for signs of blowing snow and wind slabs below treeline, especially in clearings and areas with dead trees.  Wind slabs typically form below ridges and high points. The wind wrapping around north and south aspects can cause cross loading. Use visual clues such as wavy surface texture and pillowy drifits as an indicator of where this problem is present. Previous avalanches and cracking in wind deposited snow are indicators that wind slab avalanches can occur. 

    Wind can pile up snow many times deeper than the snow dropped by the storm. As wind slabs become deeper, avalanches can become larger.

    Archive photo.

    Cracking in wind slab is a good indicator that wind slab avalanches can happen.

  • Loose Dry

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

    The dry loose problem is related to the cold temperatures bringing low density snow. Dry cold powder will lack cohesion in the surface snow and can release in steep terrain. Sustained steep slopes will be the most concerning as the dry loose avalanches can entrain more snow as they move downslope.  With this problem, the terrain will play a big role in the size of these avalanches. Be cautious in steep terrain and constricted gully features. Be mindfull of terrain traps below you. Most dry loose avalanches will be small but isolated terrain may produce large avalanches.

    I am putting the distribution at all elevations and all aspects due the to the variability in recent wind speeds. In areas where the wind has scoured away some the new snow, this will be less of a problem. 

    Storm slabs will also be possible

Avalanche Discussion

Cornices will continue to build as the wind blows snow. Be cautious around ridge tops especially when you can't see over the other side. Cornices will be lurking above lee slopes. Stepping out onto a cornice can result in an unexpected fall down the slope below. 

Regioni coperte