Bollettino valanghe

Central Sierra Nevada

Sierra Avalanche Center
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Pericolo valanghe

Alta quota
1 · Debole
Limite del bosco
1 · Debole
Sotto il limite
1 · Debole
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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.

Normal caution is advised.

Problemi valanghivi

  • Cornices

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

    Snowpack instability concerns for today are minimal. NE ridgetop winds that increased last night have very little snow available for wind transport following the NE wind event on Jan 28. Windward areas above treeline are already scoured back down to rain crust, so no new wind slabs of significance are expected to form in lee areas. These same winds will slow the rate of snow surface melt in areas exposed to both wind and sun. Sun exposed areas protected from the NE winds will experience more snow surface melt today, but only minimal wet snow instability is expected. Isolated areas of human triggered roller balls, pinwheels, and loose wet sluffs are not impossible today, but the expected small size should not present a significant hazard to backcountry travelers. Exercise normal caution while traveling in the backcountry and reevaluate terrain choice if signs of instability are observed. 

Avalanche Discussion

Observations made yesterday on Incline Lake Peak (Mount Rose area) revealed recent new snow amounts of 5 inches in wind protected areas below treeline. On northerly aspects, this snow remained unconsolidated. In sun exposed areas on SE-S aspects, melt-freeze had begun to influence the snow surface. Snowpit data collected in below treeline terrain on a N aspect, 32 degree slope at 9,140' revealed a snowpack that is clearly well into the stages of rounding, but still retains residual faceted properties more so than other locations around the forecast area. Snowpit tests indicated very good stability with propagation unlikely along any of the relative weak layers below the near surface rain crust. No informal signs of instability were observed in this area. Wet surface snow up to 0.5 inches deep was observed on SE aspects at 8,600' at 11:30 am. By 1:15 pm, these same areas were beginning to refreeze under cloudy skies.

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