Bulletin d’avalanche

Central Sierra Nevada

Sierra Avalanche Center
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Danger d’avalanche

Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
Périmé — ce bulletin a expiré 10 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Moderate avalanche danger exists at all elevations due to wind slab and loose wet avalanche problems.  Human triggered wind slab avalanches remain possible today in near treeline and above treeline terrain.  Loose wet avalanches are possible in below treeline terrain.  Evaluate snow and terrain carefully and make a plan to avoid areas of concern.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1

    Wind slabs will continue to be possible today on NW-N-NE-E-SE aspects in near treeline and above treeline terrain.  Wind slabs will continue to grow with strong to gale force SW winds today.  Look for blowing snow, cornice formation, wind pillows, and snow surface clues to identify where wind slab development is occurring.  Avoid steep wind loaded terrain.

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1

    Loose wet avalanches are possible on all aspects in below treeline areas.  The possibility of light rain and varying cloud cover throughout the forecast area may increase the chances for loose wet avalanches today.  Most of these are expected to be in the form of roller balls but in some areas loose wet avalanches could be large enough to injure or bury a backcountry user.

    Look for wet surface snow, roller balls, rain on new snow, and any signs that rapid warming of the snow surface is occurring.  Small terrain traps, such as creeks or gullies, could have big consequences with a small loose wet avalanche.      

Avalanche Discussion

Observations were made and received yesterday from Stevens Peak (Carson Pass area), Elephants Graveyard (Carson Pass area), Frog Lake Cliffs (Carson Pass area), Granite Chief Peak (Squaw Valley area), Negro Canyon (Donner Summit area), and Mt. Rose.  Skier triggered avalanches were reported at Frog Lake Cliffs, Granite Chief Peak, and Negro Canyon.  An avalanche airbag was deployed to avoid a potential burial at Frog Lake Cliffs.  This avalanche was on a NE aspect, near 9000', 1' deep, on a 40 degree convex rollover.  Strong to gale force SW winds were reported area wide with snow transport occurring.  Most avalanches observed yesterday were wind slabs, but loose wet and storm slab avalanches were also reported.

Régions couvertes