Bulletin d’avalanche

Central Sierra Nevada

Sierra Avalanche Center
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Danger d’avalanche

Thu
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
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Périmé — ce bulletin a expiré 5 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Warm sunny weather with decreasing winds will make a loose wet avalanche problem possible as daytime warming occurs.  MODERATE avalanche danger will exist at all elevations today.

Problèmes avalancheux

  • Loose Wet

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

    Another good refreeze of the snow surface has occurred overnight at most locations throughout the forecast area.  Warmer temperatures today along with decreasing winds is expected to soften the snow surface much faster than yesterday.  While the majority of loose wet instabilities will be focused on E-SE-S-SW-W aspects, they could also occur on NW-N-NE aspects with the high sun angles, warm temperatures, and decreasing winds.  As these surface melt freeze crusts soften and break down from intense solar radiation and rapid warming this morning, loose wet avalanches will become possible at all elevations.

    Monitor snow surface softening while traveling in the backcountry.  The window for good corn snow is expected to be shorter and earlier than yesterday.  As the snow surface becomes deep and wet, it's time to change aspects or move to lower angle terrain.  Roller balls and pinwheels will indicate that the snow surface is loosing strength and larger loose wet avalanches could start to occur.  Downslope hazards and terrain traps could increase the consequences of involvement with even small loose wet avalanches. 

Avalanche Discussion

* Reports of well developed melt freeze crusts from multiple areas yesterday with a good overnight refreeze of the snow surface.  Depending on wind exposure, the corn window was slightly delayed or extended longer yesterday than previous days.  

* Melt freeze crusts exist or are forming on E-SE-S-SW-W aspects throughout the forecast area at most elevations.  Most NW-N-NE aspects are still transitional with a surface crust over recent storm snow.  

Régions couvertes