Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

Sat
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Strong March sunshine with warmer temperatures will cause wet snow to form on sun exposed slopes.  Wet loose avalanches will become possible as daytime warming occurs today.  Be prepared for changing conditions and watch for any signs of unstable snow.

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    Strong solar radiation from intense March sunshine will cause wet snow to form on sun exposed slopes.  Slightly warmer temperatures with light East winds will be more favorable in forming wet snow today.  Wet loose instabilities such as roller balls and pinwheels are expected to occur today with larger wet loose avalanches possible. 

    If the snow surface becomes wet and deep, it's time to change aspects or move away from avalanche terrain.  Terrain traps such as: cliffs, rocks, trees, or gully features, could have increased consequences even with small wet loose avalanches.  Sun exposed slopes could become increasingly unstable as daytime warming occurs today.

Avalanche Discussion

  • A large and widespread avalanche cycle occurred on Tuesday March 14 during a wet and warm Atmospheric River storm.  Widespread wind and wet slab avalanches have been reported with large cornice collapses throughout the forecast region.  Many of these avalanches were up to size D3 with potentially a size D4.  See the media gallery below or our observation page for more details.
  • Rain on Tuesday March 14 went up to 9000' and potentially higher in some areas.
  • A cornice collapse shed cycle started to occur on Tuesday March 14 during the warm and wet AR storm with high elevation rain.  Large cornices continue to exist throughout the forecast region and some could weaken and collapse over the next couple days with intense solar radiation and warmer temperatures.  With the current weather conditions, widespread cornice collapses like what was seen on Tuesday are unlikely.
  • The heavy wet snow and rain during Tuesdays storm fell on less dense snow creating a large density change in the upper snowpack.  This layer has been gaining strength over time, even though snowpack tests in some areas continue to show unstable test results.  No avalanches have been reported or thought to have occurred since the end of the last storm cycle on Tuesday night.
  • Supportable melt freeze conditions have formed quickly on southerly aspects in low to mid elevation areas.  Cold overnight below freezing temperatures have made for firm snow conditions in the morning with snow surface softening by the late morning in these specific areas. 

Regions covered