Avalanche forecast

Eastside Region

Eastern Sierra Avalanche Center
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Avalanche danger

Sun
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Increasing winds and new snow will lead to fresh wind slab development near and above treeline today, with peak instability expected overnight.  When in doubt, choosing travel routes with lower slope angles in sheltered terrain will limit your exposure.

Avalanche problems

  • Wind Slabs

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

    Increasing winds and loose surface snow may lead to some fresh windslab development during daylight hours.  A quick-moving storm system may bring up to 10” of new snow overnight. You can expect slabs of unstable snow to increase in size and sensitivity quickly as this storm moves into the region. Blowing snow, recent drifting, hollow drum-like snow surfaces, and shooting cracks in surface snow are all signs that indicate nearby wind deposits. Be suspect of terrain features that encourage drifting, such as the leeward sides of ridgelines, alpine couloirs, gully features, and cross-loaded depressions. Sheltered terrain with lower slope angles will offer safer riding opportunities.

    (2/7/2024)

    Skier triggered windslab, June BC

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    1.5–3

    It has been 9 days since our last confirmed slab avalanche breaking near the ground, and signs of instability have decreased in frequency throughout the region. In areas with a deeper snowpack (near the crest from Mammoth to June), basal facets are buried more deeply, and human triggers are less likely. In areas both to the north and south, basal facets are more shallowly buried and have shown more recent signs of instability, but the distribution of concerning areas is more isolated in nature. While triggering a persistent slab avalanche has become unlikely today, it will not be impossible. If triggered, a resulting avalanche is likely to involve the full depth of the snowpack and may be unsurvivable. Areas of greatest concern can be found in regions with a generally shallow snowpack and on slopes with shallowly buried rocks, trees, and convex rollovers that will act as good trigger points. We expect substantial snow over the next few days, which will further test these buried weak layers, increasing the size potential and reactivity. In the meantime, choosing lower-angle terrain with deep and uniform snow coverage will limit your exposure.

    Photo: Steve Mace

Avalanche Discussion

Rising hazard will largely be driven by the timing of our incoming storm today.  Peak instability is expected overnight, but it will be important to conduct your own localized assessments and be ready for avalanche hazard to increase quickly as new snow and increasing winds are added to the equation. While the focus of the forecast team has largely shifted to surface instabilities over the past week, it is important to remember that we still have a generally shallow snowpack and a concerning structure. Conservative terrain choice remains the most effective tool to limit your exposure.

Regions covered