Bollettino valanghe

Central Sierra Nevada

Sierra Avalanche Center
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Pericolo valanghe

Sun
Alta quota
4 · Forte
Limite del bosco
4 · Forte
Sotto il limite
4 · Forte
Non aggiornato — questo bollettino è scaduto 5 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

A strong winter storm with heavy snow and gale-force winds will create widespread unstable and dangerous avalanche conditions. Large avalanches that slide long distances down slopes could occur. Avoid travel in, near, or below avalanche terrain.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Very Likely
    Dimensione
    2–3

    Gale force SW winds and heavy snow today will pile more wind-blown snow on top of previously wind-loaded slopes. The largest wind slabs will lurk on open slopes or near ridges in near and above treeline terrain. Some of them could also form in lower elevation areas or tree-covered slopes that typically remain sheltered due to the strength of the winds. Wind slab avalanches that fail under the weight of the new snow or a cornice failure (natural triggers) will likely occur. If a person ventures onto a wind-loaded slope, they would be very likely to cause a wind slab avalanche. These avalanches could break several feet deep in wind-drifted snow and could run long distances into below treeline locations. Large fragile cornices that may break several feet away from their edges also exist above many wind-loaded slopes.

    Blowing snow and poor visibility today make accidentally stumbling onto a dangerous wind-loaded slope or close to the edge of a cornice easier. If you do get out today, give yourself an even larger margin for error. Today is not a day for getting after it, today is a day to avoid all avalanche terrain.

  • Storm Slabs

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

    The forecast calls for multiple feet of new storm snow by tomorrow morning. This storm snow will likely accumulate faster than it can bond to itself and the snow below it. Avalanches involving slabs of storm snow failing on weaknesses within the new snow are likely. Storm slabs could exist on any aspect in wind-protected near and below treeline areas including steep slopes with nicely spaced trees where people like to recreate during storms. A storm slab avalanche could easily push a person into one of those trees.  Again, avoiding avalanche terrain is the best plan during this multiday storm. 

Avalanche Discussion

* Human-triggered and natural wind slab avalanches large enough to bury or injure a person occurred yesterday. Large cornice failures also occurred. 

* Signs of wind transport and wind-affected snow were widespread and extended into some below treeline areas and more typically sheltered areas yesterday. 

* Several feet of new snow have accumulated during this multiday storm. 

Regioni coperte