Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

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Out of date — this forecast expired 3 years ago.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

Highlights

A weak snowpack continues to exist in higher elevation areas of our forecast region.  1 to 3 feet of snow sits on top of this weak snow near the ground.  Carefully assess the snowpack if traveling in areas where this avalanche problem exists.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2

    A weak snowpack structure continues to exist in higher elevation areas of the forecast region.  Areas above 8700' on the Sierra Crest and above 8300' in the mountains East of Lake Tahoe still have weak snowpack layering with consistent unstable snowpack test results reported daily.  Most, but not all, of these areas have weak faceted snow, even depth hoar, near the ground buried underneath 1 to 3 feet of snow.  No avalanches have been reported on these weak layers up to this point with decreasing signs of instabilities.  Additional future storms will reload and retest these weak layers.  Avalanches are unlikely at lower elevations below these general elevation bands where a stronger and more consolidated snowpack exists. 

    Obvious signs of instability are hard to come by these days without digging into the snow and looking at the layers.  To limit your exposure to this avalanche problem, you can recreate on non-avalanche terrain with no overhead hazard or pick areas and locations where this persistent slab avalanche problem does not exist.

Avalanche Discussion

Extended periods of clear weather and a shallow snowpack have left various weak layers on the cold, northerly aspects that do not see much sun this time of year. Facets exist near the bottom of the snowpack, on the surface, or near/between crusts. Recent warm weather has allowed the weak, faceted (sugary) snow to start clumping together in some areas. In other places, the weak layers remain dry and loose. In general, the snowpack gets weaker as elevation increases and you move east of the Sierra Crest. This persistent slab problem may linger for some time and could reactivate in future storms.

Warm weather and fog have left crusts on the snow surface up to around 8,300 ft, potentially higher in some areas.

The snowpack has become more usable, especially above 7,500 ft. There are still rocks to hit and open creeks to deal with, but not as many as there were before this last storm.

Regions covered