Avalanche forecast

Eastside Region

Eastern Sierra Avalanche Center
View on map

Avalanche danger

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Out of date — this forecast expired 4 years ago.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

Highlights

It’s not impossible to trigger a large avalanche in extreme terrain today.  Steep, rocky, unsupported slopes that harbor buried weak layers or areas with wet surface snow are potential problem spots. Avalanches are unlikely until late tonight when a potent storm moves into the forecast area. Expect the danger to rise significantly into Tuesday.

Avalanche problems

  • Wind Slabs

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

    Winds will ramp up throughout the day. In most areas, there is little snow available for transport. Steep slopes below big plateaus are the most likely to develop new wind slabs. If you see blowing snow across ridges or gullies, you can expect to find stiff slabs on the downwind side. Watch for cracking in dense surface snow on small test slopes as a sign to avoid bigger terrain. As new snow falls overnight, strong winds will have new ammo to build bigger and more sensitive slabs.

    Blowing snow across an alpine ridgeline building wind slabs on leeward slopes

  • Persistent Slabs

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

    Sugary weak snow near the base of the snowpack has slowly been gaining strength. On a regional scale, the areas where you can trigger a persistent slab avalanche have become increasingly isolated. The weak layer is closer to the surface at the northern and southern tips of the forecast area. Steep, unsupported slopes, and areas with shallow trigger points are the most suspect. Persistent slab avalanches can propagate across terrain features and can be triggered from adjacent slopes. While triggering an avalanche breaking on old snow is unlikely, the consequences remain high. If you venture into extreme terrain, consider the added consequences of triggering a large avalanche. If in doubt, you can manage your uncertainty by increasing your margin for error and using terrain choice to limit your exposure.

  • Loose Wet

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

    Riders reported large pinwheels and deep ski penetration in wet snow yesterday. High hazy clouds prevented many areas from refreezing overnight. On slopes steeper than about 40 degrees, especially near vegetation or rocks, small wet loose avalanches are not out of the question. Wet debris is difficult to escape meaning that even small avalanches can be dangerous above terrain traps like cliffs or creek beds. Rain on snow tonight will increase the hazard. 

    Rollerballs or pinwheels are often the first warning sign of wet loose avalanches (12/25/2022)

Avalanche Discussion

Warm, but otherwise unexciting, weather will continue during daylight hours. 

It has been over a week since our last reported avalanche, and field observations have generally highlighted a healing trend in the lower layers of our snowpack. Riders reported a few isolated collapses near June Mountain on Sunday. Snowpack tests have given us mixed results, though targeted snowpack evaluations in potential problem areas continue to highlight poor structure. While they have been gaining some strength, you can still find places where these lower weak layers show the potential for propagation. When in doubt, give yourself a wider margin for error by avoiding complex, rocky terrain. 

A potent atmospheric river will move into the forecast area overnight and into Tuesday. Over the next 24 hours, we expect rain on snow into the middle elevations and heavy snowfall driven by strong winds near and above treeline. Rain on snow is almost certain to produce natural avalanches. Dense, heavy snow will fall on a variety of surfaces including crusts and near-surface facets. New slabs will likely fail at these weak interfaces. Rapid new loading and water percolating into the snowpack will stress buried weak layers. In short, big changes are on the horizon.

Regions covered