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. Loose wet avalanche problems will become increasingly widespread today. A wind slab avalanche problem may linger in isolated areas. Timing is important to avoid unstable wet snow as the loose wet problem will increase in response to daytime warming. Terrain with potential wind slabs will need evaluation on a slope by slope basis as signs of instability prior to an avalanche event will likely be very limited.

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1

    As the daily warming trend continues, natural and human triggered loose wet avalanche activity will be become increasingly widespread. Expect loose wet instability to form on E-SE-S-SW-W aspects at all elevations. Loose wet instability is also expected on NW-N-NE aspects at the low and mid elevations and potentially higher depending on sun exposure. Avalanche size could be large enough to bury a person, especially if a terrain trap is involved.

    Avoid traveling on or under slopes 37 degrees and steeper where roller ball activity exists. Instability will increase as daytime warming progresses.

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    1

    Numerous areas of blowing snow were observed yesterday near and above treeline but signs of unstable wind slabs were very limited. Lingering wind slab instability could still exist in isolated areas near and above treeline on NW-N-NE-E-SE-S aspects. Slopes directly below or adjacent to cornice features are the most suspect.

    Any areas of instability will exist within greater surrounding areas of stable snow. Evaluate terrain on a slope by slope basis. Use accepted best practices for travel in or below avalanche terrain. Expose only one person at a time to slopes steeper than 35 degrees. Avoid relying on marginal islands of safety or regrouping in avalanche runout zones.

Avalanche Discussion

Observations were made yesterday on Incline Lake Peak (Mount Rose area) and received from Shirley Canyon (near Squaw Valley). On Incline Lake Peak, blowing snow existed at treeline and plumes of blowing snow were visible off of the summits of surrounding above treeline peaks. Signs of wind slab instability were difficult to find in the snowpack with very limited and minor skier triggered cracking of surface wind slabs. Snowpit tests in a recently wind loaded area did not reveal signs of instability. In Shirley Canyon, significant warming and roller ball activity was reported on all aspects including true N below 7,700'. This was with moderate winds and significant cloud cover. Glide cracks up to 15 feet deep were noted as an additional hazard in the area.

Regions covered