Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

Fri
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Out of date — this forecast expired 5 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Slabs of wind drifted snow may still be a concern today in open areas.  Full sun and warming temperatures may also deteriorate some of these wind slabs and cornices that have formed on sun exposed terrain.  Identify areas where recent windblown snow has accumulated and cornice features have formed.  

Avalanche problems

  • Wind Slabs

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

    The last week of strong to gale force wind events from many different directions have created hard and soft wind slabs on multiple aspects in near and above treeline areas.  Lingering avalanche instabilities continue to be possible today as these wind slabs gain more strength.  Additional solar radiation and warmer temperatures today may also weaken some of these wind slabs and cornices on aspects that receive full sun.  Snow surface conditions are a mix of wind affected snow, hard wind slab, and punchy wind crusts.

    Look for areas that have accumulated recent windblown snow.  Slopes below cornices, gully features that have been cross loaded, and hollow sounding hard wind slabs, are the most likely areas for a hard wind slab to fail.  These hard slabs could break further above you and wider than expected.  Cornices could become weaker today and fail as rapid warming occurs.        

Avalanche Discussion

* A natural avalanche ( thought to be a cornice collapse) hit Hwy Old 40 in the Donner Summit area yesterday.

* Evidence of freezing rain and rain crusts were found up to and over 8000' along the Sierra Crest. 

* As warming occurred yesterday, small roller ball activity was observed in many areas.

Regions covered