Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
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Highlights

Rapid warming caused by April sun and warm temperatures will cause the avalanche danger to rise to CONSIDERABLE today. Large human-triggered loose wet avalanches will be likely today if people venture onto slopes where wet snow exists. Natural loose wet avalanches will be possible. This warming will also weaken the lingering wind slabs making human-triggered wind slab avalanches possible. Avoid slopes where signs of warming or wet snow exist and slopes where wind slabs remain especially if they receive sunshine.   

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1

    Strong April sunshine and much warmer daytime temperatures will cause rapid warming to occur in the new snow today. This rapid warming will weaken the new snow and human-triggered loose wet avalanche activity will become likely on any slopes that receive sunshine today. Some natural loose wet activity will be possible as well. These loose wet avalanches could entrain all of the new snow and could involve enough snow to pose problems for backcountry travelers. While loose wet avalanches should comprise most of the wet snow instabilities, some isolated wet slab avalanches are not impossible on the most sun-exposed slopes where the most new snow exists. 

    Avoid slopes where signs of rapid warming like sticky wet surface snow, roller balls, pinwheels, or other signs of wet snow exist. Once the sun hits the slopes today, the snow will quickly become unstable and less fun to recreate on. Seek out shaded sheltered slopes where the snow remains cold and non-wind-affected for better and safer recreation. 

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Human-triggered wind slabs will remain possible on wind-loaded slopes where wind slabs formed during the storm. Today's rapid warming caused by a combination of sunshine and warming temperatures could also weaken the bonds holding these wind slabs to the slopes and make them more fragile and easier to trigger as the day warms up. Wind slabs could exist on wind-loaded N-NE-E aspects as well as on cross-loaded NW and SE aspects. Any wind slab avalanches that occur today could involve enough snow to bury or injure a person. The largest and most fragile wind slabs will exist in near and above treeline terrain in areas where the most new snow has accumulated on slopes that receive sunshine.

    Clues like cornices above slopes, drifted snow, ripples in the snow surface, and other wind created textures can help identify where fragile wind slabs may exist. Use this information to avoid the wind slabs and to find sheltered non-wind-affected snow to travel on.

Avalanche Discussion

Observations yesterday on Carson Pass, Echo Peak, Shirley Canyon, Silver Peak, and Incline Lake Peak all found 8 to 12 inches of new snow resting on top of wet rain crusts with wet snow beneath them. Some skier triggered loose wet avalanche activity was reported on lower elevation slopes in some areas. At the upper elevations, active wind-loading was widespread, but signs of wind slab instability were limited. Observers did report some small skier triggered loose dry sluffs. Skiers on Incline Lake Peak also triggered a small slab avalanche on a steep E facing slope. This slab was only 3 to 4 inches deep but did propagate across a slope.

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