Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

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

HIGH avalanche danger will continue as the next storm impacts the forecast region today and through tonight.  Very dangerous avalanche conditions will exist.  Travel in or near avalanche terrain is not recommended.

Avalanche problems

  • Wind Slabs

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

    Wind slabs will be very likely on NW-N-NE-E-SE aspects in near and above treeline terrain due to strong to gale force SW winds and additional snowfall.  Existing wind slabs and cornices will remain fragile from yesterday and will continue to grow in size today and tonight.  Some wind slabs could form on other aspects or in below treeline terrain as wind speeds reach in excess of 100mph later today.  Large destructive wind slab avalanches could run down into below treeline terrain.  Travel in or near avalanche terrain is not recommended.

  • Loose Dry

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

    Storm slab avalanches will be very likely today and through the night on all aspects in near and below treeline terrain.  Increasing snowfall intensity throughout the day along with fluctuations in temperatures will create weaknesses within the storm snow.  Areas that have buried surface hoar below the recent storm snow could produce large avalanches that involve all the recent storm snow.  These avalanches could have wide propagation, be remotely triggered, and could occur below traditional ridgeline start zones.  Avoid avalanche run out zones and areas below steeper connected terrain.  

Avalanche Discussion

*  2 small skier triggered storm slab avalanches were reported on Incline Lake Peak (Mt. Rose area) yesterday in near treeline terrain.  Snowpack tests also showed weakness within the new storm snow just above the old snow/new snow interface.

*  Small test slope wind slab avalanches were intentionally triggered by snowmobile near Jackson Meadows.  Wind loaded test slope was NE aspect at 7600'.  Heavy snow and wind transport was reported.

*  Observations on Hidden Peak (West Shore area) reported wet heavy snow at lower elevations below 8000' with much more snow, 12'' +, above 8000'.  Signs of instabilities were limited to above 8000' where wind transport was occurring.

*  Up to 2' of snow was reported in Hope Valley with S5 snowfall rates in the morning.  The buried surface hoar layer was found but was non-reactive at this location. 

Regions covered