Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

Fri
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Strong winds and new snow last night mean avalanches are likely today where wind-blown snow has piled up on open slopes, near ridges, or in gullies. Avalanches may also happen in sheltered areas where the new snow slides down steep slopes. Watch out for signs of unstable snow like recent avalanches, blowing snow, cracking snow, and snow sluffs. Move to gentler terrain if signs of unstable snow exist or if you have any uncertainty about a slope.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    Expect to find new and unstable wind slabs near ridges, in gullies, and on open wind-exposed slopes today. The largest wind slabs will exist on leeward-facing slopes in near and above treeline terrain, but some wind slabs could also lurk in open areas below treeline due to the strength of the winds. The wind should remain strong enough to keep piling snow onto the wind-loaded slopes today. Human-triggered wind slab avalanches are likely today and could be large enough to bury people.

    Recent avalanches, cornices above a slope, blowing snow, snow drifts, and wind-created surface textures can all help identify places where unstable wind slabs exist. Use this information to reduce your risk of triggering a wind slab by giving wind-loaded areas a wide berth. Travel plans focusing on terrain sheltered from the wind will also likely lead to more consistent and less wind-affected snow.

    (2/12/2021) An example of a skier-triggered wind slab avalanche on Mt. Judah from a previous winter.

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    This storm should have deposited lighter snow on top of heavier snow (right-side up) since temperatures decreased as the snow fell. Still, varying snowfall intensities and other changes during the storm may have produced weaknesses in the storm snow. People will likely trigger sluffs of loose snow on steep, sheltered slopes due to poor bonding within the new snow or between the old snow surfaces and the new snow. Some soft slab avalanches may also be possible in areas where the storm snow has more cohesion or where wind-affected snow exists.

    Small loose snow avalanches could knock a person over or push them into areas that magnify the consequences of small avalanches. Long, steep slopes can produce larger loose snow avalanches since they entrain more snow as they slide downhill. Recent avalanches, snow sluffs, spindrift, or cracks in the snow can indicate storm snow weaknesses. If any signs of instability exist, you can move to terrain less steep than 30° to reduce your exposure and enjoy the snow. 

    (2/2/2024)

    This is an example of a long-running, loose, dry avalanche on Cathedral Peak in the Fallen Leaf Lake area from an earlier storm this year.

Regions covered