Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
Out of date — this forecast expired 8 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

The avalanche danger will remain LOW and avalanche activity will remain unlikely until it starts snowing this evening. Continue to use normal caution when traveling in the backcountry especially in areas where old firm wind slabs may linger. The avalanche danger will increase quickly as snow starts to accumulate tonight and could reach CONSIDERABLE during the night.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1

    Avalanche activity large enough to bury or injure a person will remain unlikely until it starts to snow tonight. Some isolated areas of unstable snow may still linger in wind-exposed terrain around the forecast area in the form of small, firm, and difficult-to-trigger wind slabs. Even though avalanches remain unlikely today, continue to practice responsible backcountry travel by creating good safety margins, stopping to talk to your partners, traveling through avalanche terrain one at a time, regrouping out of avalanche terrain, and constantly reassessing terrain and conditions. 

    Choosing to avoid areas with lingering firm wind slabs where unlikely but not impossible instabilities could exist and planning to recreate on the less exposed slopes represents one way to create a great safety margin that would also lead to finding the remaining areas of soft surface snow. 

    Once the storm arrives this evening, the avalanche danger will increase quickly as new fragile wind slabs become larger and more widespread during the night.

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    As stated above, avalanche activity remains unlikely today. However, once new snow starts to accumulate tonight, storm slab avalanches may become possible.

Avalanche Discussion

* Observations from Trimmer Peak found some small firm wind slabs resting on top of softer weaker snow in isolated areas. Ski kicks on these isolated drifts did result in some shooting cracks. The largest of these wind slabs still only extended about 40 ft. downslope. Smaller firm wind slabs also existed in a few areas around Ginny Lake and Slab Cliffs, but none of these were more than a few inches deep and did not extend more than a few feet downslope.

* Variable wind-affected snow surface conditions ranging from firm wind scoured surfaces to firm wind packed snow have been reported in wind exposed areas.  In less exposed areas, a mix of variable crusts exists on sun-exposed aspects with some areas of soft unconsolidated snow (near surface facets) still lingering on sheltered northerly aspects.

* In many areas on NW-N-NE-ENE aspects, weak snow exists on or near the top of the snowpack and new loading could result in instability. 

* Observations and snowpit data from Castle Peak, Johnson Canyon, and the Slab Cliffs area yesterday all indicated that the lower snowpack consists of well-bonded snow.

Regions covered