Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Out of date — this forecast expired 12 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Areas 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 thin overnight refreeze holding the snowpack together. Human triggered loose wet avalanches will become possible. Natural avalanches remain unlikely but not impossible.

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Clear skies last night should have allow the snow to radiate enough heat out into the night for a thin refreeze to have occurred even though temperatures stayed well above freezing. This thin refreeze will melt quickly as the strong April sunshine hits the slopes and daytime temperatures rise towards the mid to upper 50's above 7000 ft. 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. 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

Observations continue to show a snowpack consisting mostly of melt-freeze conditions on all aspects. Each day the snowpack has become unsupportable wet snow once the overnight refreeze melts. Yesterday on Andesite Peak this change occurred in a span of 20 minutes around 11 am. The supportable crust topped with 2 to 3 cm of wet snow quickly became deep wet snow with ski pen to 20 cm at that time. In areas where the snowpack cannot radiate heat out into the night sky (like tree covered areas) little to no refreeze occurred.

Regions covered