Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
Out of date — this forecast expired 10 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Considerable avalanche danger will continue throughout the forecast area as another storm impacts our region.  Wind slab and storm slab avalanche problems will be very likely at all elevations.  Natural triggered avalanches will be possible and human triggered avalanches will be likely.  Dangerous avalanche conditions exist.  Conservative decision making and terrain choices are critical today.

Avalanche problems

  • Wind Slabs

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

    Strong to gale force S/SW winds will form wind slabs on W-NW-N-NE-E-SE aspects near treeline and above treeline.  In some areas, these wind slabs will continue to build in size from yesterdays storm creating potential large and destructive wind slab avalanches.

    Avoid steep wind loaded terrain.  Look for blowing snow, cornice formation and wind pillows as clues to where wind slabs exist.

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1

    Storm slab avalanches will be likely on all aspects near treeline and below treeline today.  An additional 8 to 12'' of new storm snow is forecasted above 7000'.  This new storm snow will have difficulty bonding to our existing snowpack and there could also be weakness within the new storm snow.

    Signs of storm snow instabilities could be snow surface cracking, snow collapsing, and whumpfing.  Avoid slopes steeper than 30 degrees in areas where signs of unstable storm slabs are present.

Avalanche Discussion

Observations were made and received from Jakes Peak (West Shore area) and from Shirley Canyon (Squaw Valley area).  Reactive skier triggered storm slab avalanches occurred at both locations with many natural storm slab avalanches observed.  These storm slabs were in the 6 to 12'' range and grew larger throughout the day.  On Jakes Peak, snowpack tests showed additional weakness deeper within the storm snow but no avalanche activity was observed on these deeper layers.  Moderate to strong snowfall continued throughout the morning and into the afternoon on the West Shore with storm snow approaching 2 feet at the higher elevations. 

Regions covered