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

LOW avalanche danger will transition to MODERATE avalanche danger as the likelihood of loose wet and wind slab avalanche problems increase throughout the day.

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    For the second night in a row, conditions were not ideal for snow surface refreeze with cloud cover and above freezing air temperatures at about 8,200' and below. Snow surface melt rates are expected to be fairly slow today with loose wet avalanches eventually becoming a problem on all aspects and at all but the highest elevations. Avalanche size is generally expected at D1 with up to size D2 possible. How quickly this avalanche problem develops will be dependent on the strength of the surface refreeze and daytime melt rate. Rain below 7,500' may help get this avalanche problem going today.

    Continuously monitor snow surface supportability and surface crust strength and thickness. When the surface crust loses supportability or melts away exposing deeper wet snow, the loose wet avalanche problem is present and it is time to exercise options to adjust terrain choices accordingly.

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Following the onset of new snowfall, wind slabs will become an increasing avalanche problem late today, tonight, and into tomorrow morning. SW winds are expected to drift new snow onto NW-N-NE-E-SE aspects in near treeline and above treeline areas, creating unstable wind slabs in lee areas. Avalanche size is expected at D1 late today and increases to size D2 overnight.

    Identify the areas of concern where unstable wind slabs may exist. Use clues such as areas below cornices, wind pillows, and snow surface texture to identify the likely location of wind slabs. Move around these areas cautiously and with an increased margin for error.

Avalanche Discussion

* Observations made yesterday on Angora Peak (Desolation Wilderness area) and on Silver Peak (Pole Creek area) noted a weaker but still decent snow surface refreeze from the night before.

* Yesterday on Angora Peak, small (size D1) loose wet avalanches were skier triggered during the afternoon hours. After about 2:30 pm, snow surface supportability was lost.

* Snowpack instability is expected to occur near the surface, with the deeper snowpack generally well bonded. The exception might be glide cracks.

 

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