Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

MODERATE avalanche danger exists in near and above treeline terrain due to wind slab avalanche problems. Human-triggered avalanches will remain possible today. Expect avalanche conditions to become more complex and dangerous as a winter storm arrives tomorrow.  

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2

    Wind slabs and cornices will grow in size and extent on near and above treeline NW-N-NE-E-SE aspects as the intense SW winds continue. New, firm, dense wind slabs now exist on top of older wind slabs. Some wind slabs may be stubborn (difficult to trigger) and some may be more sensitive. Human-triggered wind slab avalanche activity will remain possible today. Some of the wind slabs could break above the person on the slope. Areas with trigger points, where the wind slabs are thinner, and unsupported slopes represent terrain where triggering a wind slab could be easier.

    Identify where wind slabs may exist by using clues like blowing snow, cornices above a slope, firm hollow-sounding snow, and wind features on the snow surface. Use this information to manage your group and implement appropriate safety margins. Traveling in terrain sheltered from the winds could lead to softer more consistent snow conditions with less potential for wind slab problems.

Avalanche Discussion

* Yesterday observations from Tallac and Tamarack found windy conditions in exposed areas with intense blowing snow and dense wind slab formation near ridges. On Tamarack ski kicks on wind-loaded test slopes revealed stubborn firm wind slabs that would only crack if the slope was undercut. Cornices remained fragile and sensitive to skier triggering.

* In more sheltered areas on Tallac and Tamarack, observers did not report any signs of instability. Soft snow did exist in the sheltered areas. Snowpit data on different aspects of Tamarack showed a strengthening snowpack.

Regions covered