Avalanche forecast

Eastside Region

Eastern Sierra Avalanche Center
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Avalanche danger

Sat
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Recent warming is adding uncertainty to the likelihood of triggering an avalanche. Be wary of steep leeward slopes with shallow and variable snow depth, especially those ending in terrain traps. 

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3

    Despite the lack of recent avalanche activity, whumpfs and stability test results continue to indicate that a persistent slab avalanche is possible.  Persistent slab avalanches are most likely today in drainages where the average snow depth is less than 3 ft. In these areas, the 12/01 facet layer is within 50 to 80cm of the snow surface and human-triggering is more likely. After a cold December, the transition to above-normal temperatures over the last 48 hours may increase the likelihood of human-triggering in the short term. You can increase your margin for error by avoiding shallow rocky start zones on northerly aspects with evidence of recent wind loading. Avoiding these kinds of slopes, especially if they end in a terrain traps. 

  • Wind Slabs

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

    Strong southwest winds may have formed fresh wind slabs overnight. These will be mostly small and in isolated areas, as there is very little snow available for transport on windward slopes. Wind slabs will be most problematic in extreme terrain, or around terrain features where an avalanche could step down into older layers, triggering a persistent slab. Take note of changes in the surface snow around terrain features that block or re-direct winds. Shooting cracks in the upper snowpack and small thin slabs on test slopes may mean you can trigger a wind slab in your area.

Avalanche Discussion

In the backcountry around Mammoth Lakes, the snowpack is deeper and therefore stronger than in the rest of the region. In other areas, the snowpack feels very different.  These are also the drainages that have seen fewer visits from backcountry travelers since the last storm so there are fewer data points and lower forecaster confidence. If you have been riding primarily around Mammoth Lakes, but are planning to push into terrain south of the Sherwin Ridge, or north of June Mountain, approach your trip with an assessment mindset and slowly build up before committing to challenging or complex terrain.  

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