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Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

You can still trigger an avalanche in isolated pockets where stiff wind-drifted snow rests on a weak sugary base. Thin coverage remains the primary backcountry hazard with rocks, trees, and other exposed terrain increasing the potential consequence of avalanche involvements or slips and falls. A change in the weather pattern arrives this afternoon with a few inches of snowfall expected overnight into Saturday.

Avalanche problems

  • Persistent Slabs

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

    In isolated areas wind-drifted snow sits on weak layers of facets and depth hoar at the base of the snowpack. If triggered, the resulting avalanche could break unexpectedly involving the full depth of the snowpack, making it more difficult to escape the slab and increasing the likelihood of collisions with rocks, trees, and shallowly buried objects in the runout. Persistent slabs are slow to gain strength and can remain a concern over an extended period. Managing this problem may be more difficult for backcountry riders because poor snow coverage means that the few areas attractive for riding are generally the same slopes where the avalanche problem may exist. The best strategy is to remain patient and stick to lower-angle terrain.

     

     

    (12/24/2023)

    This avalanche failed on buried facets and likely ran on 12/21

    Photo: Clancy Nelson

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    Two days ago a pulse of strong SW winds combined with a dusting of new snow along the Sierra Crest to form thin wind slabs in some leeward terrain features at upper elevations. These wind slabs may be more likely in the northern part of the region which had measurable new snow accumulation (up to 2") in the past 48 hours. While not large enough to bury you these slabs could be a concern in steep or exposed terrain where a short ride or a tumbling fall may have serious consequences. Look out for stiff hollow feeling snow and shooting cracks in the upper snowpack, especially if you are transitioning to steep terrain around ridges at upper elevations.

    (12/28/2023)

    Hard wind slab in the Sherwins just below the ridge in North facing terrain.

    Photo: Steve Mace

Avalanche Discussion

Remember thin coverage is the main backcountry hazard at the moment. On a regional scale, continuous snow coverage is largely confined to upper elevations and areas closer to the Sierra crest. The exception to this is centered around the Mammoth area where some continuous coverage exists below treeline. If you venture out into the backcountry, be ready to contend with terrain riddled with rocks, fallen trees, exposed bushes, and open water.

We have a very weak snowpack structure. Our current snowpack structure more similar to a continental snowpack than what we typically see here in the Eastern Sierra. In a continental snowpack, avalanche hazard is slow to rise and slow to fall. There is still uncertainty about whether or not tomorrow's snowfall will be heavy enough to substantially increase the hazard. In the meantime, it is important to remember that we are in a tricky situation where travel options are extremely limited and areas with “enough” snow to travel are the same areas where an avalanche is more likely to occur.

Regions covered