Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

Sat
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

High winds and new snow have created thick slabs of wind drifted snow.  Identifying and traveling around these areas of wind drifted snow will be crucial to avoiding todays avalanche problem.  Backcountry travelers could trigger large avalanches today.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2–3

    Gale force southwest winds yesterday and last night transported intense amounts of snow throughout and after our recent storm.  These SW winds have begun to decrease in speed early this morning and should get down into the moderate range today.  Most wind slabs will exist in near treeline and above treeline areas on NW-N-NE-E-SE aspects, but some could also extend to below treeline areas and other aspects due to the previous intense winds.  Wind slab avalanches are expected to be large to very large in size today with human triggering likely.  Huge cornices tower over many slopes along ridges and could remain fragile today.  These would be large wind slab avalanche triggers if they did collapse onto a slope.

    Look for wind pillows, large cornices above a slope, and wind textured snow surfaces as clues to where wind slabs have formed.  Wind slabs will be thick and dense and will not offer the same snow quality as in wind protected below treeline areas.  Plan routes around steep wind loaded terrain and avoid slopes below large cornices. 

    (1/5/2023)

    Large natural wind slab avalanche by Frog Lake, Donner Summit area.

Avalanche Discussion

  • Observations have been limited in the last 24 hours.  Natural avalanche activity along with other signs of instability have been reported.
  • Intense blowing snow was reported yesterday in exposed areas with very limited visibility. 
  • Recent winds have scoured away snow on exposed windward slopes exposing a firm icy rain crust, especially below 9000'.

Regions covered