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 will exist at all elevations due to loose wet avalanche problems becoming possible again today. Rain on snow and warm temperatures will allow this problem to continue through the night. Expect the avalanche danger to increase on Friday and Saturday as a strong storm impacts the area through Saturday.  

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Little to no freeze may have occurred last night due to above freezing overnight temperatures and overnight cloud cover. Warm weather today and a chance for light rain this afternoon should melt whatever refreeze did occur and loose wet avalanche activity will become possible again today.  Loose wet instability should continue through the night as rain continues to fall. Rising snow levels may also allow rain to fall on small amounts of new snow in areas above 8000 ft. Wet snow instabilities could include pinwheels, rollerballs, and loose wet avalanches. Some of the loose wet avalanches could involve enough snow to injure a person. Loose wet instabilities could form on any aspect today and tonight.

    Rain on snow (especially new snow), boot-top-deep wet snow, active roller balls or pinwheels, and other loose wet avalanches can indicate increasing wet snow instability.  Once signs of wet snow exist, move lower angle slopes or call it a day.

Avalanche Discussion

* Spring snow conditions with 2 to 3 inches of wet corn snow resting on top of a supportable melt-freeze crust existed on E aspects of Mt. Houghton below 10000 ft and on NW-N-NE-E aspects of Elephants Hump between 7600 and 8300 ft. by 11 am. yesterday. 

* Observations targetting the Feb. facet layer on Silver Peak, Jakes Peak, and on Elephants Hump this week have shown that this layer remains loose and that fractures could still travel along the layer if it breaks. Data has also indicated that it would take a very large trigger to get enough force through the strong snow above it to break this layer. A large loading event like the forecasted atmospheric river type storm could overload this layer. This layer was responsible for the widespread deep slab avalanche cycles in March.

Regions covered