Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

Fri
Alpine
4 · High
Treeline
4 · High
Below
4 · High
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Highlights

A large storm brings multiple feet of heavy snow to our area with very strong winds.  Large and destructive avalanches are expected today.  Travel in, near, or below avalanche terrain is NOT recommended.

Avalanche problems

  • Wind Slabs

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

    Multiple feet of heavy snow is forecasted today with gale force SW winds and wind gusts well over 100mph over the upper ridges and peaks.  Large wind slabs and cornices are expected to continue to build out today as rapid loading occurs in near and above treeline areas.  Large destructive wind slab avalanches could run long distances into below treeline locations.  Travel in, below, or near avalanche terrain is not recommended.

  • Storm Slabs

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

    Rapid snow loading is forecasted for today with 2-3''/hour snowfall rates.  Multiple feet of snow expected today and tonight along with rapid snowfall rates will lead to unstable storm slabs.  Storm slabs avalanches could fail at the new snow-old snow interface or within the new storm snow due to rapid snow loading or changes in snow levels.  If snow levels rise more than forecasted, storm slab avalanches could have wet slab characteristics.  These storm slabs could exist on all aspects in wind protected near and below treeline areas.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    1–2

    Rain on snow will cause more wet loose avalanche activity today.  In many areas, the snow surface is wetted up to 7500-8000', which caused some wet loose avalanche activity yesterday.  A much larger and powerful storm is expected today with more rain causing the bonds in the upper snowpack to further deteriorate.  If snow levels rise more than forecasted, this problem could become much more widespread with larger and deeper wet loose avalanches.

Avalanche Discussion

* Gale force SW winds were building out wind slabs and cornices throughout the day at near and above treeline locations.  Small reactive wind slab avalanches were reported along with multiple signs of instabilities.

Regions covered