Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

MODERATE avalanche danger exists at all elevations today. Wind slab and loose wet avalanche problems are possible. Either of these problems could have consequences for backcountry travelers.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Blowing snow and shifting winds mean that slabs of wind drifted snow could exist on almost any wind-exposed aspect. Newer wind slabs will exist on slopes loaded by the NE winds. Older more difficult to trigger wind slabs may still linger on slopes loaded by SW winds. Some human-triggered wind slab avalanches large enough to bury injure or kill a person may remain possible today. Complex or extreme terrain including couloirs, cliffy areas, unsupported slopes, and steep convex rollovers will be the most suspect. Large cornices also still exist along the ridgelines.

    Cornices, blowing snow, drifted snow, firm hollow sounding snow, and other wind created surface textures can help identify where wind slabs may exist. These areas will also have more challenging snow conditions including scoured surfaces, sastrugi, and firm wind-packed snow. Seeking out more sheltered terrain will provide softer more consistent snow with fewer avalanche concerns.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Strong March sunshine and warmer daytime temperatures may cause enough warming for wet snow to form on sun-exposed slopes despite the cool NE winds. Loose wet instabilities like roller balls, pinwheels, and loose wet avalanches will be possible today. Some of these will remain small. Some of them could entrain enough snow to have consequences for backcountry travelers especially on long, steep, sun-exposed slopes or in areas where terrain traps increase the severity of an avalanche.

    Wet surface snow, small pinwheels, and roller balls can foreshadow larger loose wet avalanches. Expect wet sticky snow and variable sun crusts in addition to more loose wet avalanche concerns on sun-exposed slopes. Moving to more shaded and sheltered northerly aspects can help find colder soft snow and reduce exposure to avalanche concerns.

Avalanche Discussion

* Yesterday plumes of blowing snow could be seen all along the Sierra Crest and in the Carson Range as the NE winds moved snow across the ridgelines. 

* Observations near Carson Pass found wind affected snow surfaces on all aspects near ridgelines with a mix of scoured surfaces, sastrugi, and firm wind slabs present. 

* Observations on sheltered northerly aspects near Carson Pass did not find any signs of instability. These areas still held soft cold snow as of yesterday. On the southerly aspects, a sun crust had formed.

* Snowpit data from near the crown of a recent avalanche in Davis Creek showed a layer of lighter snow under a layer of more dense snow on an E aspect. 

Regions covered