Bollettino valanghe

Central Sierra Nevada

Sierra Avalanche Center
Vedi sulla mappa

Pericolo valanghe

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

In sintesi

Avalanche danger remains LOW for all elevations and aspects. Small wet snow instabilities may form in isolated areas of direct sun exposure in response to daytime warming. Normal caution is advised.

Problemi valanghivi

  • Cornices

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

    Air temperatures were well above freezing last night at the mid and upper elevations. A decent overnight snow surface refreeze is expected to have occurred despite the warm air temperatures. This is due to radiational cooling under partly cloudy skies and aided by the longer night this time of year. As daytime warming progresses, isolated areas of minor wet snow instability may form on SE-S-SW aspects that receive fairly direct sun exposure. On northerly aspects, slab avalanche activity remains unlikely today. Weak snow that exists near the snow surface in many areas generally lacks a sufficient overlying slab. Exercise normal caution and keep an eye out for potential isolated areas of localized instability.

Avalanche Discussion

Observations made yesterday on Castle Peak (Donner Summit area) revealed areas of wet surface snow up to 2 inches deep forming on S aspects at 8,100' by late morning. Overall solar input remains limited by the low sun angles of early January. E and W aspects that had received fairly indirect sun angles by mid day remained mostly frozen. The low sun angle is also allowing for N aspects to remain shaded and colder. Below the variable snow surface conditions, a generally well bonded and stable mid and basal snowpack exists. Near crust facets associated with the uppermost rain crust in the snowpack continue to develop and weaken, but are not an instability concern at this time.

Regioni coperte