Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

Alpine
1 · Low
Treeline
1 · Low
Below
1 · Low
Out of date — this forecast expired 13 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

The avalanche danger has returned to LOW on all snow covered slopes. Human triggered avalanches are unlikely today but not impossible. Some unstable snow may continue to lurk on isolated terrain features. The SE-S-SW-W aspects do not have enough snow cover on them to warrant a danger rating.

Avalanche problems

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    1

    Observations and data collected during and since the storm on Saturday, have indicated that the meager new snow accumulation did very little to change the overall avalanche conditions. The snowpack still contains buried persistent weak layers on the near and below treeline NW-N-NE aspects. In some areas a shrinking snowpack has caused the weak layers to fragment, and they no longer connect across large slopes. In other areas the loss of snow has simply decreased the weight on top of the persistent weak layers. In still other areas, the snow above the buried persistent weak layers has lost strength creating a snowpack with weak snow on top of weak snow with no slab above the weak layers. All of these factors combined have made triggering avalanches unlikely. Unlikely does not mean impossible. Some unstable snow may still lurk on isolated terrain features on NW-N-NE aspects. Use hand pits, pole probes, and other observations to look and feel for stronger higher density snow on top of lower density snow. If this stratigraphy exists, stop and evaluate the weak layer below the slab to see if it could still fracture.

    Even though the avalanche danger has deceased, the barely covered rocks, logs, trees, stumps, and other obstacles including areas of bare ground on all aspects still make on-the-snow-recreation challenging. All of these things have become difficult to avoid, and collisions with these things could easily injure a person or break equipment. 

Avalanche Discussion

Yesterday on Red Lake Peak, observations showed 1 to 3 inches of new snow sitting on top of the ground or a very shallow snowpack on lower elevation slopes. On the N-NE aspects above 8000 ft. the new snow rested on top of a 10 to 24 inch snowpack. The old weak layers still exist in the snowpack, and the whole pack continues to lose strength and facet. On more exposed near treeline N-NE aspects, small 4 to 7 inch deep wind slabs had formed in some areas. General observations, test slope cuts, and snowpit data did not yield unstable results concerning the small wind slabs. The data showed some variable results concerning the buried persistent weak layers; however, most data pointed to a weak but stable snowpack.

Regions covered