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 12 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Pockets of MODERATE avalanche danger will form on the sun exposed E-SE-S-SW-W aspects on slopes 35 degrees and steeper today. Daytime warming and strong March sunshine will allow conditions conducive for loose wet avalanches to form on those aspects.

Problèmes avalancheux

  • Loose Wet

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

    Cold temperatures and clear skies should have allowed a strong refreeze to occur last night on all aspects. The strong March sunshine and daytime highs well above freezing may melt through this refreeze on the sun exposed E-SE-S-SW-W aspects today. Once the frozen surface melts loose wet snow instabilities will again become possible on these aspects. Most of these wet snow instabilities should remain limited to roller balls, pinwheels, and small wet snow sluffs, but some of them could entrain enough snow to cause problems for backcountry travelers. The shaded northerly aspects should remain frozen today.

Avalanche Discussion

Yesterday on Castle Peak, hard frozen rain crusts with 6-12 inches of wet snow below them existed on all aspects before 9 am. On any slopes that received sunshine the surface crust quickly melted leaving behind wet unconsolidated snow. Ski cuts and small cornice drops on the E-SE-S-SW aspects resulted in large pinwheels and loose wet snow sluffs by 10 am. On the more shaded NW-N-NE aspects the frozen surface crust remained frozen, and observations and tests did not reveal any signs of instability on these aspects. Above 8000 ft. on the northerly aspects, the frozen surface crust would support a skier. Below 8000 ft. its strength remained more variable: sometimes breaking under the weight of a skier and sometimes supporting the skier's weight.

Régions couvertes