Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

Sat
Alpine
4 · High
Treeline
4 · High
Below
4 · High
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Highlights

Blizzard-like conditions with gale-force winds and more snow will lead to widespread avalanche activity over the next few days. Avalanches could be large and slide long distances down slopes. It's best not to take a chance and ruin your holidays, avoid travel in, near, or below avalanche terrain.

Avalanche problems

  • Storm Slabs

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

    Multiple feet of new storm snow has accumulated over the last 24 hours with more snow expected today. Changing conditions during the storm have created weaknesses within the new snow. Avalanches involving slabs of storm snow failing on these weaknesses will remain likely today. These storm slabs could exist on any aspect in wind-protected near and below treeline areas. Storm slabs often exist in places where people go to recreate during a storm like steep slopes with nicely spaced trees. A storm slab avalanche in one of those areas could easily push a person into one of those trees.  Again, avoiding avalanche terrain is the best plan during this multiday storm. 

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    2–3

    Large slabs of wind-blown snow already exist in near and above treeline terrain especially on open slopes or near ridges. More snow and gale force SW winds that gust over 100 mph will cause these wind slabs to grow in size and extent today. Due to the blizzard-like conditions, wind slabs may extend into areas at lower elevations or onto more tree-covered slopes that typically remain sheltered. Natural wind slab avalanches will likely occur and human-triggered wind slab avalanches are very likely if a person ventures onto a wind-loaded slope. Large wind slab avalanches could run long distances into below treeline locations.

    Blowing snow and poor visibility will make stumbling into a dangerous spot easier since seeing what terrain exists above or around you will be difficult. If you do get out today, give yourself an even larger margin for error. Traveling in, below, or near avalanche terrain is not recommended.

    (12/23/2021)

    This wind slab was triggered by a backpack size piece of cornice kicked onto the slope.

    Photo: Andy Anderson

Avalanche Discussion

* Human-triggered wind slab avalanches occurred on several test slopes yesterday. 

* Ski cuts on small test slopes and micro features in sheltered terrain started to produce cracking and movement indicative of storm slabs by yesterday afternoon. 

* Below 8000 ft, a layer of rain-soaked snow exists below the new snow. 

Regions covered