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

MODERATE avalanche danger lingers near and above treeline. LOW avalanche danger exists below treeline. Blowing snow is expected today with the possibility of a wind slab avalanche problem. Air temperatures warming to near freezing today will allow for a very slight possibility of a loose wet avalanche problem.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Increasing SW to W winds today will create areas of blowing snow in near treeline and above treeline terrain. Redistribution of snow on the ground will allow for the possibility of new wind slab formation. New wind slabs may be difficult to trigger today (stubborn or possibly unreactive).  New wind slabs will likely be small with a potential avalanche size of D1 expected (not large enough to bury a person). Consequences would come from being pushed into rocks or trees, over a cliff, or into a terrain trap.

    Identify and avoid areas of potentially unstable wind slab by looking for newly wind drifted snow. Slopes that have cornice features or wind pillows across the upper portion of the slope are the most suspect. Areas of snow surface cracking in near treeline and above treeline terrain are an additional indication of unstable snow.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    1

    Loose wet is an unlikely avalanche problem today but cannot be ruled out if strong solar radiation occurs simultaneously with near freezing air temperatures during the mid day or afternoon hours. This will be fairly dependent on how rapidly and to what extent sun obscuring cloud cover develops today.

    Look for natural or human triggered roller balls occurring in sun exposed, wind protected areas near treeline and below treeline on SE-S-SW aspects as the first sign of the potential for small (size D1) loose wet avalanches to occur.

Avalanche Discussion

* Blowing snow with little in the way of problematic wind slab formation has been noted near and above treeline around the forecast area over the past two days. Winds have shifted back and forth between SW and NE.

* A few very small loose dry avalanches were observed yesterday on very steep slopes in the Ebbetts Pass area.

* Faceted snow either with or without an associated crust has been noted 1 to 1.5 feet below the snow surface in the Carson Pass and Ebbetts Pass areas. This layer warrants monitoring but has yet to become problematic due to the low density and lack of slab characteristics in the overlying snow.

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