Bollettino valanghe

Central Sierra Nevada

Sierra Avalanche Center
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Pericolo valanghe

Wed
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
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Non aggiornato — questo bollettino è scaduto 4 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

New snow and strong wind will create potentially dangerous avalanche conditions today. Watch out for fragile slabs of wind-blown snow on slopes near ridges or in gullies and unstable storm snow on open slopes in sheltered areas. Travel plans that focus on terrain not steep enough to avalanche can help avoid today's avalanche problems.

Problemi valanghivi

  • Wind Slabs

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

    Gale force SW winds and new snow will create fragile wind slabs on the leeward side of ridges, in gullies, and on open slopes exposed to the wind today. These wind slabs will quickly become large enough to produce avalanches capable of burying or injuring a person as snow accumulates. Human-triggered wind slab avalanches will become likely today. Natural wind slab avalanches may also be possible in some areas. The largest wind slabs will exist in near and above treeline terrain on NW-N-NE-E-SE aspects. Any breaks in cloud cover this afternoon could make these wind slabs easier to trigger.

    Watch out for signs of wind-loading like blowing snow, cornices above a slope, snowdrifts, and wind-created surface textures. Avoiding areas where fragile wind slabs might exist represents a good plan. Traveling on lower-angle slopes in wind-sheltered areas can help avoid potential wind slab issues and may provide softer, more consistent snow conditions.

  • Storm Slabs

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

    Intense snowfall rates and dense snow this morning could create unstable slabs of storm snow on steep slopes in wind-protected areas near and below treeline. Storm slab avalanches could grow large enough to cause problems for backcountry travelers, especially in areas with terrain traps like creeks, gullies, or cliffs that magnify the consequences of an avalanche.

    Look for cracking in the snow or signs of cohesion within the new storm snow to help identify where unstable storm slabs may exist. Keep evaluating conditions as you travel and be willing to move to lower angle terrain whenever you encounter signs of instability. If the sun breaks through the clouds later today, the new snow will warm up quickly and wet snow instabilities could occur. 

Avalanche Discussion

  • Many NW-N-NE-E aspects have good snow coverage. Snow cover on most SE-S-SW-W aspects is limited to the snow that has fallen since April 10. Prior to this recent snow, most of those aspects had large areas of bare ground on them. 
  • Snowfall since April 10 has greatly favored the Sierra Crest in the northern half of the forecast area. Substantial improvements in snow cover have occurred in this portion of the forecast area.

Regioni coperte