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
1 · Faible
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Périmé — ce bulletin a expiré 9 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

In most areas along the Sierra Crest, the avalanche danger will remain LOW today due to cooler temperatures, cold NE winds, and a lack of significant new snow accumulation. Across the Lake in the Mt. Rose area and in other high-elevation areas across the region where more snow fell, areas of MODERATE avalanche danger will exist in near and above treeline terrain where wind slabs may exist. If more warming occurs today than forecasted, some loose wet instabilities may form. 

Problèmes avalancheux

  • Wind Slabs

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

    In the Mt. Rose area and in other isolated high-elevation areas across the region where the most snow accumulated during the storm, some human triggered wind slabs may remain possible today. Most of these should remain small and not extend very far away from the ridgelines, but a few larger wind slabs could exist in isolated areas where the most snow fell. The wind slabs will most likely exist where the NE winds have wind-loaded W-SW-S aspects and cross-loaded NW and SE aspects in near and above treeline terrain. Sun on these aspects this afternoon could also weaken the wind slabs. Along the Sierra Crest where less than 3 inches of new snow accumulated, wind slabs should remain too small to represent a significant avalanche problem due to the minimal amounts of new snow. 

    The cooler temperatures, continued cloud cover, and cold NE winds should prevent loose wet instabilities from becoming widespread. If more warming occurs than forecasted today, loose wet instabilities could form on slopes where new snow exists. 

Avalanche Discussion

Yesterday observations on the far east ridge of Tamarack Peak found 4 to 5 inches of new snow and wind slabs up to 8 inches in depth. Ski kicks produced cracking and some small wind slab failures on test slopes in this area. Across the Lake on Andesite Ridge less than an inch of new snow existed. This dusting of new snow rested on top of a breakable rain crust above a few feet of wet unsupportable snow. This crust was quickly refreezing. Observations revealed no signs of instability in this area. In both places strong to gale force winds scoured slopes and transported snow all day exposing firm icy surfaces and creating some wind slabs in the Mt. Rose area. 

Régions couvertes