Avalanche Advisory published on January 24, 2017 @ 6:34 am
This Avalanche Advisory expires in 21 hours, 33 minutes
This advisory is valid for 24 hours
Issued by Brandon Schwartz - Tahoe National Forest
bottom line

MODERATE avalanche danger exists near treeline and above treeline due to wind slabs. Below treeline LOW avalanche danger exists in wind protected areas. Areas of instability will exist within greater surrounding areas of seemingly good stability. This could create a false sense of security. Avoid relying on marginal islands of safety or grouping up in runout zones. Evaluate slopes and terrain carefully, especially when changing elevation bands or changing from one aspect to another.

How to read the advisory


  • Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

2. Moderate

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Above Treeline

2. Moderate

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Near Treeline

1. Low

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Below Treeline

MODERATE avalanche danger exists near treeline and above treeline due to wind slabs. Below treeline LOW avalanche danger exists in wind protected areas. Areas of instability will exist within greater surrounding areas of seemingly good stability. This could create a false sense of security. Avoid relying on marginal islands of safety or grouping up in runout zones. Evaluate slopes and terrain carefully, especially when changing elevation bands or changing from one aspect to another.

  • Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
Avalanche Problem 1: Wind Slab
  • Character ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Ongoing areas of blowing snow yesterday combined with shifting winds today will keep the concern for unstable wind slabs ongoing. The vast majority of wind slabs will exist near treeline and above treeline on NW-N-NE-E-SE aspects. Smaller new wind slabs may form today near treeline and above treeline on S-SW-W aspects. If today's NE winds are stronger than forecast, new wind slabs will be larger and more widespread.

Look for areas of blowing snow, recent cornice formation, and wind pillows to determine specific slopes where wind slabs likely exist. Avoid travel on slopes with terrain traps below such as cliffs, creek beds, and deep gullies.

CURRENT CONDITIONS Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 6 to 14 deg. F.
Max. temperature in the last 24 hours: 19 to 25 deg. F.
Average wind direction during the last 24 hours: SW
Average wind speed during the last 24 hours: 15 mph
Maximum wind gust in the last 24 hours: 29 mph
New snowfall in the last 24 hours: Trace to 2 inches
Total snow depth: 122 to 148 inches
weather

A mix of sun breaks and light snow showers is expected today as unstable air remains in place over the region. Air temperatures remain on the colder side with air temperatures this morning above 8,000' in the single digits and teens. Ridgetop winds are shifting to the NE this morning. Wind speeds are forecast to remain in the light to moderate speed range today and tonight. Winds are expected to shift back to the W tomorrow ahead of an approaching weak weather disturbance.

 

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
  Today Tonight Wednesday
Weather: Mostly cloudy skies. A slight chance of snow showers throughout the day. Partly cloudy skies. Partly cloudy skies, becoming mostly cloudy.
Temperatures: 21 to 26 deg. F. 3 to 13 deg. F. 24 to 29 deg. F.
Wind direction: Variable Variable W
Wind speed: Light winds Light winds Light winds. Gusts up to 25 mph in the morning.
Expected snowfall: Trace in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
  Today Tonight Wednesday
Weather: Mostly cloudy skies. A slight chance of snow showers throughout the day. Partly cloudy skies. Partly cloudy skies, becoming mostly cloudy.
Temperatures: 17 to 22 deg. F. 7 to 13 deg. F. 22 to 28 deg. F.
Wind direction: NE N W
Wind speed: 10 to 15 mph with gusts to 30 mph. 10 to 15 mph with gusts to 30 mph. 15 to 20 mph with gusts to 40 mph.
Expected snowfall: Trace in. 0 in. 0 in.
Disclaimer

This avalanche advisory is provided through a partnership between the Tahoe National Forest and the Sierra Avalanche Center. This advisory covers the Central Sierra Nevada Mountains between Yuba Pass on the north and Ebbetts Pass on the south. Click here for a map of the forecast area. This advisory applies only to backcountry areas outside established ski area boundaries. This advisory describes general avalanche conditions and local variations always occur. This advisory expires 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.

For a recorded version of the Avalanche Advisory call (530) 587-3558 x258

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