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

In sintesi

Pockets of MODERATE danger will form on all aspects at all elevations on slopes 37 degrees and steeper as daytime warming and sunshine melt through the overnight refreeze that holds the snowpack together. Human triggered loose wet avalanches will become possible. Natural avalanches remain unlikely but not impossible.

Problemi valanghivi

  • Loose Wet

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

    Most of the cloud cover cleared out of the skies after 1-2 am last night, and temperatures dropped into the mid to upper 30's. This period of clear skies and cooler overnight lows should have allowed a slightly stronger overnight refreeze. While the intense April sun and daytime highs well above freezing should still melt through this refreeze today, it may last longer due to slightly cooler daytime highs, some expected cloud cover, and the fact that it was a slightly stronger refreeze. Once the refreeze melts, enough unconsolidated wet snow will exist for human triggered loose wet avalanches including pinwheels, roller balls, and loose wet snow point release avalanches to become possible on all aspects at all elevations. Most of these loose wet avalanches should remain small, and they should remain more isolated in distribution today due to the cooler weather and expected cloud cover.

    Getting out early and leaving the slopes before last night's refreeze completely melts represents a good way to avoid dealing with unsupportable wet snow. Once the refreeze does melt the recreation conditions deteriorate and the avalanche hazard increases. At that point finding a different afternoon activity that does not involve steep snow covered slopes is a great idea.

Avalanche Discussion

The snowpack continues to shrink. Remote sensors are reporting about 5 cm of melting each day. Bare ground and rocks that were once snow covered have reappeared. In areas where snow cover remains, deep wet unsupportable snow forms each day as the thin overnight refreezes melt. Yesterday on Becker Peak observations supported these general trends as well. Snow cover has become patchy on the SE-S-SW aspects. By 11:30 am 20 to 30 cm of wet snow existed on the N-NE-E aspects and 15 to 20 cm of wet snow existed on the slightly more supportable SE-S-SW aspects. Ski cuts on steep north facing test slopes did trigger small loose wet snow sluffs that did not entrain very much snow.

Regioni coperte