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
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Périmé — ce bulletin a expiré 11 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Areas of MODERATE avalanche danger will form today on slopes 37 degrees and steeper in response to daytime warming. Widespread loose wet instability in the form of roller balls, pinwheels, and loose wet avalanches not large enough to bury or injure a person are expected. Areas of MODERATE danger will be most widespread NW-N-NE-E aspects where snow cover existed prior to the last storm and may form in very isolated areas on SE-S-SW-W aspects.

Problèmes avalancheux

  • Loose Wet

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

    As daytime warming progresses, areas of loose wet instability will become widespread at all elevations today on slopes 37 degrees and steeper. Roller balls and pin wheels will be widespread today as snow falls off of rocks and trees. Loose wet avalanches not large enough to bury or injure a person are possible today. The vast majority of instability is expected to occur on NW-N-NE-E aspects today where significant snow cover existed prior to the most recent storm cycle. Due to the fact that most SE-S-SW-W aspect slopes were bare ground prior to the last storm cycle, loose wet avalanches will be very isolated on the most sun exposed aspects. Keep in mind that terrain traps such as gullies and cliffs below can greatly magnify the consequences of very small avalanches that would otherwise be too small to bury or injure a person. 

Avalanche Discussion

Observations made yesterday on Mt. Judah (Donner Summit area) indicated that avalanche problems had transitioned from wind slabs to loose wet instability. Intentional human triggered cornice collapses, ski cuts, and snowpit tests revealed no evidence of ongoing wind slab instability. Wind slabs up to 1.5 feet deep in near and above treeline on NW-N-NE-E aspects that had failed secondary to natural cornice collapse in the area on Monday were no longer unstable. Widespread human triggered roller balls and pin wheels up to 8 inches in diameter were noted on NW-N-NE-E aspects. No signs of actual loose wet avalanches were observed.

Régions couvertes