Bulletin d’avalanche

Central Sierra Nevada

Sierra Avalanche Center
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Danger d’avalanche

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

Points saillants

Avalanche danger is LOW for all elevations on snow covered NW-N-NE-E aspects. Encountering an isolated area of unstable snow has become unlikely, but may still be possible due to the variability that can exist on a regional scale. 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

    Any areas of instability that continue to exist are most likely to be found near treeline on NW-N-NE aspects were surface slabs sit on top of weaker faceted snow. Otherwise, generally stable snowpack conditions have been observed on a regional scale. Triggering an isolated wind slab or persistent slab avalanche is unlikely but not impossible. Recent field observations still show the occasional unstable snowpit test result mixed in among the vast 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

Observations made yesterday on Lincoln Ridge (Yuba Pass area) revealed lingering wind slabs. These wind slabs had formed near treeline on northerly aspects during the January 11 snowfall event and were deposited on top of faceted snow. These slabs proved difficult to trigger and evidence of instability was limited. Once sufficient force was applied to collapse the faceted weak layer, snowpit tests indicated that the resulting fracture could propagate through the snowpack. The general trend recently observed in other locations around the forecast area has been indicative of better snowpack stability. Either the weak layers have sufficient strength to support the overlying load or the surface slab is not strong enough to allow snowpack collapse to travel any significant distance through the snowpack.

Régions couvertes