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 6 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Triggering an avalanche is becoming increasingly unlikely but not an impossibility. Do not underestimate potential avalanche size even though LOW avalanche danger exists for all elevations. Continue to exercise caution and guard against the potential for isolated instability by using proper travel techniques in avalanche terrain.

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely
    Dimensione
    2

    The odds of triggering a persistent slab avalanche continue to decrease. The areas holding a weaker shallower snowpack and greatest lingering concern are in the Carson Pass and Ebbetts Pass areas, especially to the east of the Sierra Crest. In many locations within the northern 2/3rds of the forecast area, the Dec 11 faceted PWL has gone dormant. 

    Continue to exercise caution and be wary of potential trigger points such as areas near exposed rocks. Signs of any isolated instability are not likely to readily present themselves. If you happen to encounter the isolated collapse, crack, or unstable snowpit test, scale back terrain choices to sub 30 degree angle slopes without steeper slopes above.

Avalanche Discussion

* Recent observations from around the forecast area are showing continued improving stability associated with the Dec 11 faceted PWL in the lower portion of the snowpack. Stability improvements have occurred more rapidly in the northern 2/3rds of the forecast area where the snowpack is deeper. In the southern 1/3rd of the forecast area, especially to the east of the Sierra Crest the snowpack remains shallower and weaker.

* Faceting is beginning to form around the recently formed rain crust that exists in the upper snowpack in areas below about 7,800' to 8,200'. 

* Large surface hoar was reported yesterday from low and mid elevation areas. This is expected to form and become destroyed numerous times before the next snowfall.

* A variety of snow surface conditions exist. Some soft snow remains on sun and wind sheltered upper elevation slopes. In wind exposed areas wind-scoured, wind-packed, and/or rain crusted surfaces are present.  Very superficial surface melt-freeze is occurring on slopes with direct sun exposure. The above noted rain crust is widespread and sometimes breakable, sometimes supportable.

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