Bollettino valanghe

Central Sierra Nevada

Sierra Avalanche Center
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Pericolo valanghe

Alta quota
1 · Debole
Limite del bosco
1 · Debole
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 12 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Avalanche danger is LOW for all elevations and aspects.

Normal caution is advised.

Problemi valanghivi

  • Cornices

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely
    Dimensione
    1

    With decreasing cloud cover, greater amounts of incoming long wave solar radiation are expected to create a few inches of surface wet snow today. Any areas of wet snow instability that form are expected to remain minimal and not pose a significant threat to backcountry travelers. Areas around exposed rocks and bushes may become full depth wet snow today. These areas already have well established free water drainage and are not expected to pose much of an instability issue.

    On northerly aspects a weak layer of generally poorly developed near crust facets that exist below the uppermost rain crust within the snowpack warrants continued monitoring. Finding an area where this weak layer is capped by a slab with the proper characteristics for a slab avalanche to occur remains highly unlikely. As evidenced by the recent small avalanche on Castle Peak, it is not an impossibility. Do not allow this dry spell to generate complacency for best practice travel techniques in and around avalanche terrain.

Avalanche Discussion

Observations made yesterday on Rubicon Peak (West Shore Tahoe area) and on Castle Peak (Donner Summit area) revealed a mix of snowpack conditions. Snowpit tests targeting near crust facets in the upper snowpack showed further decreases in strength on northerly aspects both on Rubicon Peak and on some areas of Castle Peak. On other northerly aspects on Castle Peak, this weak layer was nonexistent. Evidence of a several day old small slab avalanche with a crown depth of 6 to 8 inches was noted on Castle Peak in a NW aspect gully at 8,500'. The trigger is unknown with a multitude of ski and snowmobile tracks in the area. Cornice collapse is also a possibility. Based on recent observations from the area, the avalanche is believed to have occurred sometime within the past seven days.

Snow surface conditions were noted to remain frozen all day on northerly aspects in most areas with minor amounts of wet snow formation on southerly aspects.

Regioni coperte