Bulletin d’avalanche

Central Sierra Nevada

Sierra Avalanche Center
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Danger d’avalanche

Wed
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
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Périmé — ce bulletin a expiré 2 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

People may still trigger avalanches where slabs of wind-blown snow exist on open slopes, near ridges, or in gullies. In some places, enough warming may occur for sluffs of wet snow. Watch out for any signs of unstable snow, like recent avalanches, cracking, or wet snow. You can reduce your chance of triggering an avalanche by using less steep slopes and sticking to areas without wind-blown snow. 

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2

    Despite a lack of new snow, intense wind yesterday managed to scour existing snow from the windward-facing slopes and deposit it onto the leeward-facing slopes. People triggered small wind slab avalanches yesterday afternoon. These wind slabs will still exist near ridges, in gullies, and on open slopes exposed to the wind today. Most of them should remain small since very little new snow fell, but some may be large enough to cause problems for people. If fresh slabs of wind-drifted snow rest on surface hoar, wind slab avalanches could be wider than expected. If this combination does exist, it would most likely be in near treeline, NW-N-NE facing terrain. Wind slabs could shift locations later today if the N winds grow stronger than forecast. 

    Look for drifting snow, wind drifts, cornices above a slope, and snow surface texture to identify where wind slabs may exist. Recent avalanches or cracking in the snow can indicate that these wind slabs remain unstable. Travel plans that focus on terrain sheltered from the wind can reduce the chances of triggering a wind slab avalanche and may help find more consistent snow. 

     

    (2/26/2024) This skier-triggered wind slab occurred yesterday afternoon. 

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–1.5

    Sunny skies today could provide enough warmth for some wet snow to form on the most sun-exposed aspects. In most cases, today's warming will only result in small wet snow instabilities like pinwheels and roller balls. Still, enough wet snow could form on the most sun-exposed slopes that a small sluff of wet snow may become possible. If the winds shift to the north this afternoon, it could help limit the amount of wet snow that forms. 

    Pay attention to changing conditions, and if you start to encounter wet surface snow, consider changing aspects or moving to lower-angle slopes. 

Avalanche Discussion

Across open E-S-W aspects, surface hoar was destroyed by melt. A melt-freeze crust now exists at the old snow surface across these aspects. Some surface hoar may have survived on NW-N-NE aspects in near and below treeline terrain. If so yesterday's light snow may have covered it in some places. Today and tomorrow will provide a window to see where that surface hoar may linger before the next large storm.

Régions couvertes