Bollettino valanghe

Central Sierra Nevada

Sierra Avalanche Center
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Pericolo valanghe

Tue
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 5 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Triggering avalanches may be possible in areas where wind-blown snow piles up today. These would mainly be small, but a few might grow large enough to cause problems, especially in places with the most new snow. Watch out for open slopes where wind-drifted snow exists. In areas without new snow, there is less avalanche danger. 

New snow and wind tonight and tomorrow will cause the avalanche danger to increase.

Problemi valanghivi

  • Wind Slabs

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

    Even though new snow amounts may seem small, the wind can increase snow depths by piling wind-blown snow onto leeward slopes. Some wind slabs may form on open NW-N-NE-E-SE aspects in near and above treeline terrain today. Most of these should remain small and not extend very far from the ridges due to the small amount of new snow. A few of them may grow large enough to cause problems for backcountry travelers in the most wind-loaded areas or in areas that receive the most new snow. In areas that did not get new snow or receive less snow, wind slabs will be smaller, more isolated, or may not exist. 

    Look for clues like blowing snow, drifted snow, cornices above a slope, and wind-created surface textures to help identify where wind slabs might exist. Recent avalanches or cracking represent sure signs that wind slabs are unstable. Identify areas where triggering a wind slab may be possible before committing to a slope. Areas sheltered from the winds will hold more consistent and less wind-affected snow. 

    As more snow and wind impact the forecast area tonight and tomorrow, wind slabs will grow larger and become more widespread. Other avalanche problems could also develop in more sheltered areas. 

Avalanche Discussion

  • Snowmelt has sped up since the beginning of February. Many more obstacles (rocks, bushes, etc) and areas of bare ground have melted out on SE-S-SW aspects.
  • The light snowfall from Feb 15 helped to smooth the previously rough snow surfaces in some areas. Variable snow surface conditions ranging from firm ice to soft snow remain widespread.
  • Gradual near-surface faceting during the long dry spell created weak snow in the top portion of the snowpack on many sheltered NW-N-NE aspects. Recent snow has not added enough load to create slab avalanche problems in most places, but this layer could become problematic as more snow and wind impact the area. 

Regioni coperte