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

Points saillants

Low avalanche danger will exist on all aspects and elevations in the early morning hours.  As daytime warming begins, pockets of Moderate avalanche danger will become possible on E-SE-S-SW aspects at all elevations due to loose wet avalanche instabilities.  On W-NW-N-NE aspects at all elevations, avalanche danger will remain Low throughout the day.

Problèmes avalancheux

  • Loose Wet

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

    Air temperatures above 7000' were well above freezing for another night with temps at 6am in the mid 30's to mid 40's.  Southwest winds will be in the light to moderate range above 7000' for today.  Under mostly clear skies last night, radiational cooling should have helped to marginally refreeze the snow surface.  Any refreeze is expected to be thin in most areas and melt quickly this morning.

    Human triggered loose wet avalanche activity will become possible on E-SE-S-SW aspects on slopes above 35 degrees as daytime warming occurs and the upper snowpack looses supportability.  Most of these loose wet avalanches will be in the form of human triggered pin wheels or roller balls.  In some cases, these loose wet avalanches could be large enough to injure or bury a backcountry user. 

    Timing will be important if you plan to travel on solar aspects today.  Avoid steep solar aspects and terrain traps as daytime warming occurs.  Current roller balls or pin wheels will be an indication that the snow surface has lost supportability and strength.  Hand pits and boot penetration may help give clues to upper snowpack strength.  

Avalanche Discussion

Observations from Caples Lake (Carson Pass area), Castle Peak (Donner Summit Area), and Incline Lake Peak (Mt. Rose area) all showed warm, spring like conditions.  Good snow travel was reported in the mid morning hours with conditions deteriorating quickly by noon.  On Incline Lake Peak, skier triggered loose wet avalanches were reported in the small size.  On Castle Peak, firm snow surfaces exist in exposed areas that were scoured by the recent East wind event.  North aspects on Incline Lake Peak, had pockets of unconsolidated snow mixed with variable and sticky snow at all elevations.  All locations reported punchy and unsupportable surface snow conditions on solar aspects by mid day.

Régions couvertes