Bollettino valanghe

Central Sierra Nevada

Sierra Avalanche Center
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Pericolo valanghe

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

In sintesi

Anticipate areas of developing wet snow instability by late morning on sun exposed slopes in response to daytime warming. Recently formed slabs of wind drifted snow remain a lingering avalanche concern at the mid to upper elevations. Identify slopes of concern and move around them with caution.

Problemi valanghivi

  • Loose Wet

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

    Following the cold start to this morning, wet loose avalanches will become possible again today. This problem is expected mainly in areas below about 8,500'. Prior to the expected increase in cloud cover, the strong April sunshine will warm the snow surface, leading to instability. Expect wet snow instability to develop first on slopes with direct sun exposure. This avalanche problem may spread to other slopes as the day progresses depending on the extent of building cloud cover. The sun angle is high enough this time of year to allow incoming solar radiation to affect northerly aspects.

    The development of roller balls and pinwheels, whether natural or human triggered, indicates that wet loose avalanches are possible. Once signs of wet snow instability develop, you can move to low angle terrain to avoid this avalanche problem. Keep in mind the potential for long running wet loose avalanches on longer slopes with sustained slope angles steeper than about 35 degrees.

    (4/6/2024)

    Skiers triggered these wet snow sluffs on SE aspect terrain near 7,600' around midday. The terrain wasn't quite steep enough to produce wet loose avalanches, but the snowpack was prime to do so. Silver Peak, Pole Creek, CA

    Photo: Sierra Avalanche Center

  • Wind Slabs

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

    Slabs of recently wind drifted snow exist on the downwind side of ridges, in gullies, and on open wind exposed slopes. Isolated areas where wind slabs remain unstable are a lingering concern today. The largest wind slabs exist in the areas that received the most new snow Thursday/Friday. This includes the areas around Emerald Bay, Echo Summit, Carson Pass, and Ebbetts Pass. Smaller wind slabs have been observed in other areas that received lesser amounts of recent snowfall.

    You are most likely to encounter a lingering unstable wind slab above about 8,000' where less warming has occurred. Signs of unstable wind slabs may not be obvious today. Use clues such as recent or older avalanches, cracks in the snow surface, cornices above a slope, snow drifts, and/or ripples in the snow surface to identify slopes of concern. Move around these areas with caution.

    (4/6/2024)

    A backcountry traveler unintentionally triggered this wind slab avalanche yesterday on their third turn down the slope. They were caught and carried with no burial or injury. NE aspect terrain, Carson Pass area, CA

    Photo: Public

    Additionally, a smaller wind slab avalanche was triggered yesterday by a snowmobiler near Mt. Lola, CA (photos below).

Regioni coperte