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 6 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Avoid wind loaded slopes in avalanche terrain (slopes steeper than 30 degrees). In specific terrain, wind slab avalanches could be large. It has been a while since storm slabs have made an appearance on the problem list, and here they are. Ease into the terrain and check out how the storm snow is reacting before committing to steep and/or convex terrain. Remember, anytime you feel unsure about the snow stability, just keep your terrain choice to slopes less than 30 degrees.

Problemi valanghivi

  • Wind Slabs

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

    On Friday afternoon, blowing snow was visible in wind exposed areas. In near treeline terrain there were drifts double to triple the depth of new snow. I expect that trend to continue throughout Friday night and into Saturday. Even on the low side of the forecast, we could see 5+ inches of new snow by Saturday morning which could translate into winds slabs up to several feet thick. Expect wind slabs to be in forming on lee slopes.

    Wind slabs are easiest to trigger while they are actively being formed and while they are still new. Saturday fits that description. Take loaded slopes seriously. In much of the terrain wind slabs will be small, but in specific pockets they will be large.

    Watch for signs of blowing snow, fresh cornices, pillow drifts, and wavy surface texture as signs that slopes are wind loaded.

  • Storm Slabs

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

    Storm snow totals could reach the 8-10" mark by Saturday morning. If we hit the upper end of the snow forecast we could see another 5" or more by midday Saturday. If you see cracking in the storm snow as you move through the terrain, avoid steep slopes and pay special attention to the convex terrain features. Conexities are common places where storm slabs tend to initiate.

    If the new snow is showing little or no cohesion, storm slabs will be less of a concern. Best to keep it on the radar for now.

     

     

Avalanche Discussion

Skiing and riding condtions will be good in wind protected areas as more soft snow piles up. The wind will be moving a lot of snow Friday night and Saturday. Windward slopes will likely be scoured to the 12/22 rain crust while lee slopes could see quite substantial wind loading. When snow gets stripped from one slope, it has to go somewhere. 

As you move through the terrain, keep an eye on how the snow is behaving under your skis. Anytime you see cracking as you move over small rollers or onto steeper slopes, recognize this as a sign of unstable snow and stick to lower angle terrain (<30 degrees) . Ease into terrain and get a feel for the how the storm snow is responding.

There have been no reports of recent avalanches.

Although layers of softer/weaker old snow have been found in the upper/mid pack, we are not currently dealing with any persitent weak layers. In the near future, triggering an avalanche will mostly be related to recent snow condtions in the upper pack.

Regioni coperte