Bollettino valanghe

Central Sierra Nevada

Sierra Avalanche Center
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Pericolo valanghe

Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
2 · Moderato
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Non aggiornato — questo bollettino è scaduto 7 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

MODERATE avalanche danger will exist at all elevations today as daytime warming and potential rain on snow allow loose wet avalanches to become possible. Small wind slab problems may also exist on some exposed slopes in near and above treeline terrain. 

Problemi valanghivi

  • Loose Wet

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

    Warm daytime temperatures, new snow, and potential rain showers will allow loose wet avalanches to become possible again today. The potential for this problem could be more widespread across aspects and reach higher in elevation. In areas where enough warming occurs to melt through the thin crust under the new snow, these avalanches would entrain the few inches of new snow as well as some of the wet snow below.

    Signs foreshadowing larger loose wet avalanches an include wet, sticky surface snow, roller balls, and pinwheels. These signs also herald deteriorating riding conditions. As soon as you notice them, it is time to look for aspects/elevations where colder more frozen conditions still exist.

  • Wind Slabs

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

    Strong SW winds have drifted snow onto the leeward aspects. The wind slabs that have formed on these aspects should remain small and not extend very far away from the ridgelines due to the meager amounts of new snow. Most of these wind slabs would be unlikely to cause significant problems for backcountry travelers. However, some of them could be large enough to be problematic especially in areas with terrain traps or where getting knocked off balance would have serious consequences.

Avalanche Discussion

* Yesterday on Mt. Tallac small wind slabs up to 10 inches deep had formed along exposed ridgelines by noon. These did not break in response to ski cut and tests did not show signs of instability even though they rested on a layer of less dense snow on top of a crust. They also did not extend very far down slope.

* In sheltered areas 1 to 2 inches of new snow had accumulated on top of a crust above 7800 ft. with a dusting of new snow on the crust below 7800 ft. The crust was breakable at low elevations and supportable at higher elevations.

Regioni coperte