Bulletin d’avalanche

Central Sierra Nevada

Sierra Avalanche Center
Voir sur la carte

Danger d’avalanche

Alpin
1 · Faible
Limite forestière
1 · Faible
Sous la limite
1 · Faible
Open full map
Périmé — ce bulletin a expiré 13 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Avalanche danger is LOW at all elevations on snow covered NW-N-NE-E aspects. Human triggered avalanches are unlikely but not impossible. Isolated areas of unstable snow may exist on isolated terrain features. Due to melt, avalanche danger on SE-S-SW-W aspects is generally nonexistent.

Problèmes avalancheux

  • Cornices

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

    Generally stable snowpack conditions exist on a regional scale. The unlikely possibility of triggering an isolated wind slab or persistent slab avalanche continues to linger on NW-N-NE aspects. Recent field observations still show the occasional unstable snowpit test result mixed in among a majority of stable snowpit test results. Continue to exercise caution and implement best travel practices while traveling in or below avalanche terrain in order to minimize risk.

Avalanche Discussion

The existing snowpack is generally stable, despite the presence of various weak layers and measuring in at just 20% of average depth for this time of year. Observations made yesterday on Rubicon Peak (West Shore Tahoe area) revealed stable slab conditions overlying various faceted weak layers on below treeline northerly aspects. In the big picture, the snowpack remains weak, but the facet layers have gained sufficient strength to support the overlying slab. In some areas, the surface slab has disintegrated through near surface faceting and no longer exists.

A guided group on the traditionally heavily wind loaded Wildflower Ridge, a N and NE aspect at 7,700' on Mt. Judah (Donner Summit area) reported ongoing propagation potential but significant difficulty in trigger collapse of the Dec 7 facet layer. Minor cracking was also observed in this area once surface wind slabs sitting on a buried graupel layer were undercut by ski tracks. These shallow wind slabs also proved difficult to trigger if not previously undercut.

Régions couvertes