Avalanche forecast

Central Sierra Nevada

Sierra Avalanche Center
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Avalanche danger

Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Out of date — this forecast expired 8 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

MODERATE avalanche danger still exists near and above treeline due to the potential for lingering wind slabs in some terrain. Below treeline the avalanche danger is LOW.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Strong and shifting winds have left a variety of firm and soft wind slabs, cornices, and wind scoured surfaces on exposed near and above treeline slopes. Most of the wind slabs should have become more difficult to trigger, but some human-triggered wind slabs may still remain possible today. Unsupported slopes, gullies, couloirs, cliffy areas, and other complex or extreme terrain represent the best places to find a lingering wind slab. Today's new snow and wind could form some new wind slabs as well, but these should remain small in most places due to the limited amount of new snow expected. 

    Identify the specific terrain where wind slabs may exist using clues like blowing snow, cornices above a slope, firm hollow sounding snow, and other wind created surface textures. Softer more consistent snow should still exist in most sheltered areas and could provide better recreation conditions with fewer chances for encountering wind slabs or firm wind scoured surfaces.

Avalanche Discussion

* Some small skier-triggered cracking was reported in firm wind slabs on W aspects in the Mt. Judah area and on upper elevation E aspects on Mt. Rose yesterday.

* Observers also saw ongoing wind transport near ridgelines on Deep Creek Peak, Ralston Peak, and on the peaks west of Luther Pass. Widespread signs of wind scouring including sastrugi, exposed rain crusts, and other firm surfaces existed in exposed near and above terrain and along ridgelines across the region.

* Observations from sheltered areas in the Donner Summit region, in Deep Creek, on Powderhouse Peak, on Flagpole Peak, and on Trimmer Peak all found soft snow with no signs of slab instabilities. Some surface hoar existed in the Mt Judah area, the Deep Creek area, and in the meadow near Powderhouse. 

* By the afternoon, some warming snow and thin sun crusts existed on southerly sun-exposed aspects on Mt Rose and Mt. Judah. Observers reported some small skier triggered loose wet instabilities in a steep SE facing gully on Mt. Rose. Some low elevation E aspects also had thin sun crusts on Mt. Judah.

Regions covered