Avalanche forecast

Eastside Region

Eastern Sierra Avalanche Center
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Avalanche danger

Wed
Alpine
4 · High
Treeline
4 · High
Below
4 · High
Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Rain and heavy snowfall driven by strong wind will create very dangerous avalanche conditions throughout the day. Avalanches starting in the alpine could step down to buried weak layers and run into lower elevations. Rain below 9,000 feet will make wet snow avalanches likely below treeline. Avoid traveling in and below avalanche terrain.

Avalanche problems

  • Wind Slabs

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

    Winds are gusting over 100 mph at ridgetops this morning. They are forecasted to stay at snow-blowing speeds throughout today. Blowing snow across ridges or gullies, and even downwind of trees at lower elevations will be common. Rapid wind loading means natural avalanches will be likely. Expect to trigger dense slabs in leeward terrain. These will increase in size and sensitivity at higher elevations. Avoid slopes steeper than 30 degrees with wind-blown snow. Avoid terrain beneath wind-loaded slopes.  

    (12/21/2022)

    Blowing snow Above Treeline in Rock Creek loading an E slope. 12/21/22

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3

    Sugary weak snow near the base of the snowpack has slowly been adjusting to the load of the last storm when very large avalanches broke around terrain features and below cliffs. Areas with a weak snowpack will be tested by over 2 inches of new water today. Persistent slab avalanches can propagate across terrain features that would otherwise confine surface instabilities. Rain percolating through the snowpack may mean wide-breaking avalanches near and below treeline. Wind slab avalanches may step down to buried weak layers. The resulting avalanche could break deeper and wider than expected. The consequences could be unsurvivable. 

    A storm slab avalanche that stepped down to deeper weak layers during the last storm 12/11/22

  • Loose Wet

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

    Rain on snow almost always produces wet snow avalanches. The rain-snow line could climb as high as 9,000 feet this morning. Avalanches running down to lower elevations may entrain wet snow. Wet debris is heavy and difficult to escape. Even small wet avalanches can be dangerous above terrain traps like cliffs or creek beds. 

    (12/25/2022)

Avalanche Discussion

A strong storm moved into the region early this morning. We expect rain-on-snow below treeline and heavy snowfall driven by strong winds near and above treeline. Snow levels are likely to fall by mid-morning. Rain on snow almost always produces natural avalanches. Dense, heavy snow will fall on a variety of surfaces including crusts and near-surface facets. New slabs will likely fail at these weak interfaces. Rapid new loading and water percolating into the snowpack will stress buried weak layers. Avalanches could break wider than expected and run to lower elevations. Watch your overhead hazards in the mountains, and in town.

Regions covered