Bollettino valanghe

Central Sierra Nevada

Sierra Avalanche Center
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Pericolo valanghe

Thu
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 5 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Strong winds have continued to create windblown slabs of unstable snow.  These wind slabs exist in many open areas and have been responsible for multiple avalanches over the past week.  Areas of accumulating snow, slopes below large cornice features, and places where previous wind slabs have already formed will be the concern for today.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    Strong to gale force winds continue.  These winds have shifted from the SW to the W yesterday, and will continue to shift to the NW later today.  Recent winds have been creating hard and soft wind slabs on many different aspects in near and above treeline areas with some wind slabs even forming in open below treeline terrain.  Natural and human triggered wind slab avalanches were reported yesterday throughout the forecast region and will remain a concern for today.  Snow surfaces are a patchwork of wind scoured conditions, wind slab, and a lot of wind affected snow.

    Look for blowing snow, snow surface scouring, cornice formation, and hollow drum like sounds over hard wind slabs.  These hard slabs could break further away and above you than expected.  Cross loaded gully features or anywhere wind drifted snow has accumulated will be potential for wind slab avalanches.  Avoid areas below large cornices and steep wind loaded terrain. 

    (1/4/2022)

    Natural hard wind slab avalanche triggered by cornice collapse.

    Photo: Steve Reynaud

Avalanche Discussion

* Isolated reports of buried surface hoar that formed after the large December storm and pre wind events have been seen in a few locations throughout the forecast area.  Multiple different wind events from different directions are thought to have destroyed most of this previous surface hoar.  No reported avalanches have been confirmed on this weak layer. 

* Freezing rain and surface rain crusts were found just below 7000' in the northern part of the forecast region and up to 8000' near Echo Pass yesterday.

Regioni coperte