Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Moderate Avalanche danger will exist throughout the forecast region today due to a persistent slab avalanche problem.  Widespread surface hoar has been reported throughout the area this past week.  Light amounts of new snow occurred overnight and are expected into tomorrow.  Most avalanches associated with this buried surface hoar are expected to be small, but even small avalanches can have severe consequences with our early season snow coverage.  Evaluate snow and terrain carefully today, identify areas of concern.    

Avalanche problems

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Widespread surface hoar has been observed in many areas throughout our forecast region.  This surface hoar today has up to 4'' of new storm snow on top of it with another 1 to 3'' expected today.  This small amount of new snow should not be enough today to bury a backcountry user, but could be enough to take someone on a ride into low snow covered obstacles.  You should not be surprise to see small avalanches today.  These avalanches will mostly be in the form of small loose dry (sluffing) avalanches due to no cohesion of the new storm snow.  In areas that receive the most snow, small persistent slabs could occur.

    Identify where the surface hoar exists throughout the terrain.  Quick hand pits should aid in seeing the surface hoar layer.  This will be important for today and potentially the future when our next storm arrives.  Please let us know what you see.  If your field observations show either more storm snow than forecasted or a potential wind slab on top of the buried surface hoar-you should reevaluate your plan and choose safer terrain options.     

Avalanche Discussion

*  Large widespread surface hoar reported on Silver Peak (Pole Creek area,)  Mt. Judah (Donner Summit area), and on Rubicon Peak (West Shore area) over the last 2 days.  Reports of surface hoar came in from Carson Pass and Mt. Rose over the last 4 days.

*  Signs of previous storm slab instabilities have diminished over the last 2 days.  No additional avalanches reported. 

*  Decent snow coverage exists above 7000-7500' along the Sierra Crest with slightly more coverage in the northern Sierra Crest part of the forecast area.  Snow coverage declines as you move east.  Early season conditions still exist.  Many obstacles are present including; rocks, logs, stumps, and open water.

Regions covered