Bollettino valanghe

Central Sierra Nevada

Sierra Avalanche Center
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Pericolo valanghe

Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
3 · Marcato
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Non aggiornato — questo bollettino è scaduto 9 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

CONSIDERABLE avalanche danger exists at all elevations today. Human triggered wind slab avalanches are likely on wind-loaded slopes and storm slab avalanches are possible in more sheltered locations. Dangerous avalanche conditions exist. Plan travel routes to avoid steep slopes where avalanche problems may exist. Evaluate snow and terrain carefully. If areas receive more snow and higher snowfall rates than forecasted, more avalanche danger could exist. 

Problemi valanghivi

  • Wind Slabs

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

    Large, deep, and fragile wind slabs will exist on wind-loaded slopes, and avalanches involving these wind slabs could have serious consequences. Continued wind and snow in the last 24 hours have formed additional wind slabs on top of the previous wind slabs. As more snow and wind impact the forecast area today, these wind slabs will continue to grow. Human triggered wind slab avalanches will be likely today and natural wind slab avalanche will be possible. The largest and most fragile wind slabs will exist on the wind loaded N-NE-E aspects and on cross-loaded NW and SE aspects in near and above treeline terrain, but wind slabs could also exist in some below treeline areas due to the strength of the winds. 

    Identify where wind slabs might exist by using clues like blowing snow, wind drifts, cornices above slopes, wind-created ripples, and other wind created features. Use this information to avoid the wind slabs and to find sheltered non-wind-affected snow for better and safer recreation.

  • Loose Dry

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

    Changing conditions during the storm have created softer weaker layers and stronger more slab-like layers within the storm snow. Some human triggered storm slab avalanches may be possible today in areas where the stronger slab-like layers exist above the softer weaker layers of storm snow. Storm slabs could exist on steep slopes in non-wind-affected terrain and could involve enough snow to bury or injure a person. The areas that receive the most new snow and highest snowfall rates will represent the best places to find storm slabs.

    Recent avalanche activity, shooting cracks, snowpits, and probing can all help identify where storm slabs may exist. Use this information to avoid steep slopes where storm slabs may exist. 

Avalanche Discussion

Yesterday observations on Powderhouse Peak, Incline Lake Peak, and Andesite Peak all found new snow sitting on top of refreezing rain crusts. New snow amounts varied from 10 to 18 inches. Strong winds and dense snow had formed stubborn wind slabs that would crack under repeated ski kicks on wind-loaded test slopes. Snowpit tests on Incline Lake Peak indicated that storm slab instability existed in some areas as well. 

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