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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Highlights

For most of today, LOW avalanche danger is expected to continue for all elevations and aspects. Minor wind slabs not large enough to bury or injure a person remain an issue near and above treeline on NW-N-NE aspects. As additional snowfall accumulates, wind slab size will increase and avalanche danger is expected to increase to MODERATE danger sometime late today or tonight with a further increase in avalanche danger expected during the day tomorrow.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Small wind slabs not large enough to bury or injure a person linger near and above treeline on NW-N-NE aspects. These slabs formed Saturday from S winds transporting old snow on the ground and creating new wind loading in lee areas. These slabs were most reactive on Saturday, but tiny slabs 2 to 6 inches deep and up to 6 feet wide remained reactive to skier triggering in some areas yesterday.

    Wind slabs will become larger and more dangerous as new snow is wind loaded in lee areas today and tonight. At some point between late this afternoon and tomorrow morning these slabs are expected to become large enough to bury or injure a person. At that time, active measures beyond normal caution will be necessary to manage the hazard. Take a moment to discuss with your partner and identify in the immediate surroundings the areas where these wind slabs are most likely to exist. Make and execute a plan for specifically avoiding suspect areas.

Avalanche Discussion

Observations made and received yesterday from Mt. Tallac (Desolation Wilderness area), Silver Peak (Pole Creek area), and from Andesite Ridge and Red Mountain (Donner Summit area) indicated improved wind slab stability over the previous day with a small amount of lingering instability associated with tiny wind slabs. In the vast majority of wind loaded areas tested, no signs of instability were observed. In isolated areas, a few skier triggered cracks and wind slabs up to 6 feet wide and up to 6 inches deep were triggered, but only moved a few feet down slope. These slabs were enough to knock a person off balance, but too small to bury or injure a person (Size D1).

Snow surface warming was noted on all aspects yesterday in areas below 7,000-7,500'. Roller balls were observed on steep low elevation slopes, but nothing in the way of significant loose wet instability was observed.

Regions covered