Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

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

Avalanche danger is CONSIDERABLE near treeline and above treeline. Avalanche danger is MODERATE below treeline. Wind slab and storm slab avalanche problems continue today. Backcountry travelers should not be surprised by human triggered avalanche activity at any elevation. Dangerous avalanche conditions exist in many areas. Cautious and conservative terrain decisions and route selection are warranted today. 9:50 am update to add Wet Loose avalanche problem.  

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2

    Continued SW winds and another 6 to 12 inches of new snow last night will have further developed wind slabs in near treeline and above treeline terrain on NW-N-NE-E-SE-S aspects. These new wind slabs sit on top of recently unstable wind slabs that formed during this storm cycle. Avalanches that occur today could be large and destructive. Large potentially dangerous cornices exist in many ridgeline areas.

    Use clues such as blowing snow, cornice formations, and wind pillows to help identify recently wind loaded slopes that may hold unstable wind slabs and should be avoided.

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    New snow from last night was deposited under the coldest air temperatures of this storm cycle. Weak layers within the new snow may remain reactive today and allow for storm slab avalanche activity near treeline and below treeline on all aspects. The vast majority of any storm slab avalanche activity today will be human triggered.

    Look for areas of snow surface cracking, especially while breaking trail and making fresh tracks either uphill or down. Avoid steep suspect slopes, especially in areas where snow surface cracking exists.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    9:50 am update - Cloud cover is significantly less than forecast. Loose wet avalanches are now possible on E-SE-S-SW-W aspects at all elevations. Avalanche size could range from small to large. Areas around rocks and trees will heat up quickly despite below freezing air temperatures. Avoid travel in areas where natural roll ball activity is occurring.  

Avalanche Discussion

Observations made yesterday on Hidden Peak (West Shore Tahoe area) and well below treeline on Brockway summit found density changes within the recent storm snow. These density changes did not show propagating results in snowpit tests. On Hidden Peak around 8,600' in near treeline terrain as well as near the summit, wind effects became much more pronounced with skier triggered cracking of wind slabs from ski cuts and kicks.

Regions covered