THIS AVALANCHE ADVISORY EXPIRED ON February 12, 2018 @ 6:57 am
Avalanche Advisory published on February 11, 2018 @ 6:57 am
Issued by Andy Anderson - Tahoe National Forest

The avalanche danger will remain LOW for all elevations today and avalanche activity will remain unlikely. Other hazards still exist in the backcountry. Continue to use normal caution during backcountry travel. 

1. Low

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Above Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

1. Low

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Near Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

1. Low

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Below Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
    Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
Avalanche Problem 1: Normal Caution
  • Type ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Cold temperatures and increasing clouds and winds should keep crusts frozen and firm. While avalanche activity will remain unlikely today, other dangers like long sliding falls on the frozen crusts, collisions with some of the numerous exposed obstacles, or both still exist. Continue to plan travel in the backcountry to minimize risks. 

The new snow expected tonight combined with increased SW winds may start to form small isolated wind slabs near exposed ridgelines. These wind slabs should not grow large enough to pose much of a hazard to backcountry travelers tonight due to the limited amount of new snow accumulation expected. 

recent observations

* Snow surfaces remained frozen and firm on sun-exposed E-SE-S-SW-W aspects all day yesterday on Castle Peak (Donner Summit area) and on Tamarack Peak (Mt. Rose backcountry).

* Snow coverage on E-SE-S-SW-W aspects varies significantly by location and elevation. In some areas, little to no continuous snow cover exists on these aspects below 8,200' to 9,000'. In some cases, these aspects are mostly bare ground up to elevations above 10,000'.

* Snowpit data and observations from N aspects on Tamarack Peak (Mt. Rose backcountry) and Becker Peak (Echo Summit area) showed a well-consolidated snowpack with no signs of instability. 

* Some soft, cold, unconsolidated snow still lingers on sheltered untracked N aspects. Snow surface conditions elsewhere on NW-N-NE aspects range from breakable crust to heavily tracked to firm wind scoured. Snow coverage becomes less consistent and more limited on northerly aspects below 7500 ft. in most areas.

Weather and CURRENT CONDITIONS
weather summary

Strong NE winds during the night have given way to moderate SW winds this morning. These SW winds should increase today as a small cold front approaches the area. The forecast calls for colder temperatures and a chance of snow starting tonight as the system arrives. Snow showers and clouds could linger over the area through tomorrow. This system does not have much moisture associated with it so snow accumulations may remain light with only up to 2 inches expected overnight and another possibility for up to 2 inches during the day tomorrow in some areas. By tomorrow afternoon the winds should shift back to the NE.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 31 to 37 deg. F.
Max. temperature in the last 24 hours: 37 to 42 deg. F.
Average wind direction during the last 24 hours: NE shifting to the SW after midnight
Average wind speed during the last 24 hours: 45 mph
Maximum wind gust in the last 24 hours: 105 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 27 to 48 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Sunday Sunday Night Monday
Weather: Sunny then becoming mostly cloudy. Cloudy then becoming partly cloudy. Snow likely. Mostly cloudy with scattered snow showers in the morning and widespread showers in the afternoon.
Temperatures: 37 to 42 deg. F. 17 to 22 deg. F. 23 to 29 deg. F.
Wind Direction: Southwest Southwest shifting to the west after midnight Northeast
Wind Speed: 10 to 15 mph with gusts to 30 mph increasing to 15 to 25 mph with gusts to 45 mph in the afternoon 20 to 30 mph with gusts to 50 mph decreasing to 10 to 15 mph with gusts to 25 mph after midnight Light in the morning increasing to 10 to 15 mph with gusts to 25 mph in the afternoon
Expected snowfall: 0 in. up to 2 in. up to 2 in.
For 8000 ft. to 9000 ft.
Sunday Sunday Night Monday
Weather: Sunny then becoming mostly cloudy. Cloudy then becoming partly cloudy. Snow likely. Mostly cloudy with widespread snow showers.
Temperatures: 32 to 38 deg. F. 13 to 19 deg. F. 17 to 23 deg. F.
Wind Direction: Southwest Southwest shifting to the west after midnight Northwest shifting to the northeast in the afternoon
Wind Speed: 15 to 20 mph with gusts to 45 mph increasing to 30 to 40 mph with gusts to 80 mph in the afternoon 30 to 45 mph with gusts to 85 mph decreasing to 15 to 20 mph with gusts to 40 mph after midnight 10 to 15 mph with gusts to 25 mph in the afternoon
Expected snowfall: 0 in. up to 2 in. up to 2 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