Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
View on map

Avalanche danger

Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
Open full map
Out of date — this forecast expired 10 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Moderate avalanche danger exists in near treeline and above treeline terrain due to a continuing wind slab avalanche problem.  Low avalanche danger exists in below treeline terrain.  Human triggered wind slab avalanches remain possible for today.  Avalanche danger will rise tonight and through Monday as the first in a series of storms impact our region this week.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2

    Wind slabs will continue to be a problem on NW-N-NE-E-SE aspects in near treeline and above treeline terrain.  Wind slabs will continue to grow as SW winds increase to strong to gale force this afternoon.  Human triggered wind slab avalanches remain possible today.  Existing wind slabs have grown throughout this storm cycle and could be well over 3 to 4' deep.  Avalanches associated with these deeper wind slabs would have large consequences.

    Look for blowing snow, cornice formation, wind pillows, and snow surface scouring as clues to where wind slab development is occurring or has occurred.  Avoid steep wind loaded terrain.  

Avalanche Discussion

Observations were received from Silver Peak (Pole Creek area), Andesite Peak (Donner Summit area), and Round Valley (Donner Summit area).  All areas showed continued settlement of the recent storm snow with around 2 feet of new settled snow since the storm began on Wednesday.  Rain levels were reported up to 7000' in the morning hours with generally heavy and dense surface snow.  On Silver Peak and in Round Valley,  ECT's were propagating on wind slab failures up to 1' deep in the snowpack.  Active wind loading was occurring at all locations throughout the day.

Regions covered