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
Non aggiornato — questo bollettino è scaduto 6 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Warm spring weather will quickly melt through whatever refreeze occurred last night and allow avalanches of loose wet snow to become possible before midday. Cornice fall is also a possibility. MODERATE avalanche danger will form at all elevations once the surface crust melts, exposing areas of deep wet snow.

Problemi valanghivi

  • Loose Wet

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

    Warm temperatures in most places combined with some cloud cover should have prevented much of an overnight refreeze. This morning, warm weather and strong sunshine will quickly destroy any refreeze that might have occurred exposing deep wet snow. This melting will occur on the E-SE-S aspects first and move to all other aspects during the day. The thin cloud cover forecasted for today may help spread the warming to aspects that usually receive less sun. Loose wet avalanches will become possible on steep slopes once the surface crust melts. Some of these could entrain enough snow to bury or injure a person on large steep slopes or in areas where terrain traps exist. 

    Starting early to try and catch the short window of supportable snow and finishing before the snow becomes deep and wet represents one way to avoid loose wet avalanche problems. Once the snow starts getting wet and deep, it is time to avoid avalanche terrain by recreating on lower angle terrain without steep slopes above.

  • Glide Cracks

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

    Cornices will continue to weaken due to the warm weather, strong sun, and another weak overnight refreeze. Large pieces could break off of these overhanging waves of snow as they melt. These blocks of snow could injure a person or may trigger loose wet avalanches or wet slab avalanches as they impact the slopes below them.

    A great deal of difficulty exists in predicting exactly where and when cornices will break. Often they break farther back from their edges than expected. Staying far away from the edge and avoiding spending any time underneath cornices can help avoid this problem. 

Avalanche Discussion

* Spring melt-freeze conditions exist on all aspects across the forecast area.

* Yesterday observations from Incline Lake Peak in the Mt. Rose Backcountry found shallow wet corn snow on supportable melt-freeze crusts before 10:00 am on SE-S aspects down to 8600 ft. By 10:45 these aspects had started to become unsupportable. Deep wet snow had formed on E before 10:45. Ski cuts on a small steep E facing test slope did trigger a small loose wet avalanche at 11:20. Wet sticky barely supportable snow existed on northerly aspects around 11 am. 

Regioni coperte