Bollettino valanghe

Central Cascades

Central Oregon Avalanche Center
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Pericolo valanghe

Sat
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
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Non aggiornato — questo bollettino è scaduto 3 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Triggering a slab avalanche in wind deposted snow will be possible on Friday on west, north, and easterly aspects near and above treeline. It will be possible to trigger wet snow avalanches at lower and mid elevations on slopes in the direct sun, especially during the heat of the day. Avalanches will have more consequence on long sustained slopes and above terrain traps; anytime you have uncertainty about the stability of the snowpack consider moving to lower angle options and less complex terrain. 

Problemi valanghivi

  • Wind Slabs

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

    On Thursday, there was variability surrounding the wind slab problem. In some terrain, the wind slabs were not active at all, while in at least one location a wind slab was triggered on a NE aspect near treeline; size D1. Friday will be a classic high pressure day and as people travel into the high country, it will be wise to keep this problem in mind. Wind slab avalanches still have the potential to be large, although most will be small. Be cautious on slopes that have been previously wind loaded, especially in steep and committing terrain. 

    On Thursday, the wind was light and minimal amounts of blowing snow was observed. The wind is expected to be light on Friday and I don't expect much for new wind slab formation. However, in some pockets of terrain, the wind slabs created during the last storm seem to be hanging on a little longer that usual.  

    Monitor the depth of wind slabs. Deeper wind slabs can result in larger avalanches. This problem is commonly found below ridge tops, peaks, and around features that catch blowing snow from cross slope winds. Watch for signs of wind deposited snow in clearings and areas with sparse, or dead trees.

    (3/16/2023)

    Wind slab avalanche skier triggered on Thursday. NE aspect, near treeline, size D1

    Photo: Jonas Tarlen

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    This problem will be more of a concern at the lower elevations and on steep slopes in the direct sun. The sun is becoming more intense this time of year and will have a more pronounced effect on the surface snow.  There is an abundance of soft snow on the surface that can be affected by warming temperatures and direct sun exposure. As the surface snow becomes wet, it can loose cohesion bringing on the wet loose problem. Monitor the surface conditions; as you observe wet or slushy snow boot top or deeper, wet loose avalanches can become larger. Watch for roller balls and pinwheels as precursors to this problem. Be especially cautious of triggering a wet loose avalanche in sustained steep terrain, and above terrain traps. 

    Use visual clues on the snow surface and timing to avoid this problem. Recognize which aspects are in the direct sun, especially during the warmest time of the day. 

     

Avalanche Discussion

Continue to keep a watchfull eye on cornices at ridge tops. Be catious approaching ridges from behind. Stepping out onto a cornice can result in a air drop onto the slope below. On warm days, cornices can weaken and break naturally. When you are moving through the terrain, don't linger beneath cornices, especially the big ones.

Regioni coperte