Bulletin d’avalanche

Central Sierra Nevada

Sierra Avalanche Center
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Danger d’avalanche

Mon
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

Areas of unstable wet snow will develop today as the snow surface melts in response to daytime warming. This will lead to the development of a wet loose avalanche problem at all elevations. MODERATE avalanche danger will exist today at all elevations.

Problèmes avalancheux

  • Loose Wet

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

    Despite the above freezing air temperatures last night, a decent but superficial snow surface refreeze is expected to have occurred on open slopes. This will have been driven by overnight radiational cooling of the snowpack that got started once cloud cover cleared around 11 pm. Snow surface refreeze will be relatively weaker and thinner in areas under forest canopy where radiational cooling was less efficient. Clear skies and above freezing air temperatures at sunrise will start right in on melting last night's superficial snow surface refreeze.

    Once the supportable but superficial crust on the surface has melted away, the deeper wet snow below it that did not refreeze last night will be exposed. This will open the door to a wet loose avalanche problem. Once the surface crust is no longer supportable, exercise caution in or below avalanche terrain. Utilizing terrain that is less steep than 30 to 35 degrees and without steeper slopes above minimizes exposure to potential wet snow avalanches.

Avalanche Discussion

* Spring melt-freeze conditions exist on most E-SE-S-SW-W aspects. Small wet snow instabilities like roller balls, pinwheels, and small sluffs of wet snow have been reported in several areas over the past few days. 

* NW-N-NE-E aspects still remain in between winter-like snow and spring melt-freeze conditions with a surface crust over colder dryer snow in some places, especially at higher elevations.

Régions couvertes