THIS AVALANCHE ADVISORY EXPIRED ON January 30, 2017 @ 6:59 am
Avalanche Advisory published on January 29, 2017 @ 6:59 am
Issued by Andy Anderson - Tahoe National Forest

LOW avalanche danger exists at all elevations. LOW danger does not mean no danger and unstable snow may still linger on isolated terrain features. Small avalanches could still occur in isolated or extreme terrain. Evaluate the terrain and snowpack while traveling in the backcountry to identify where these isolated areas of unstable snow may still exist.

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 ?

Triggering an avalanche has become unlikely today. Unlikely does not mean impossible and some unstable snow may still exist on isolated terrain features especially in steep complex or extreme terrain including couloirs, hanging snowfields, and steep cliffy areas. Lingering cornices could also still collapse under the weight of a person, and these could become easier to break as the day warms up. Continue to pay attention to the snowpack and terrain and make observations to identify where those isolated areas of instability may linger. Practice safe backcountry travel techniques like using low angle slopes or ridgelines to approach terrain and only exposing one person at a time to avalanche terrain. Regroup in safe zones out of avalanche paths or runout zones. 

recent observations

Observations yesterday on Schellenberger Ridge (near Donner Lake), Lincoln Ridge (Yuba Pass), and Incline Lake Peak (Mt. Rose backcountry) found a mix of surface snow conditions ranging from soft, cold, unconsolidated snow on sheltered northerly aspects to warmer wet snow and thin breakable crusts on sun-exposed southerly aspects to firm scoured or wind packed surfaces on exposed near and above treeline slopes. Surface hoar also had formed on some open areas in all three of these places. Snowpit tests and observations from these areas showed a "right-side-up" snowpack with less dense snow resting on top of layers of more dense snow. On Lincoln Ridge, large cornice pieces dropped onto previously wind loaded slopes and tests targeting lingering wind slabs did not result in signs of instability.

Weather and CURRENT CONDITIONS
weather summary

The strong high-pressure ridge over the region will keep the weather calm and sunny through Monday. The lack of wind will allow cold air that has sunk into the valleys to remain trapped at the lower elevations while the upper elevations continue to see a significant warming trend. This morning temperatures at the upper elevations have already risen above freezing in many locations while lower elevation sensors are reporting temperatures in the teens and 20's. Expect these inversion conditions to persist through tomorrow. The forecast calls for continued sunny calm weather with warm temperatures through Monday. Expect daytime highs above 7000 ft. in the mid to upper 40's today and tomorrow.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 33 to 35 deg. F.
Max. temperature in the last 24 hours: 41 to 49 deg. F.
Average wind direction during the last 24 hours: East
Average wind speed during the last 24 hours: 10 mph
Maximum wind gust in the last 24 hours: 29 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 105 to 130 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 Clear becoming partly cloudy Partly cloudy becoming sunny
Temperatures: 42 to 48 deg. F. 19 to 29 deg. F. 44 to 50 deg. F.
Wind Direction: Variable Variable Variable becoming southwest in the afternoon
Wind Speed: Light Light Light increasing to 10 mph in the afternoon
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Sunday Sunday Night Monday
Weather: Sunny Clear becoming partly cloudy Partly cloudy becoming sunny
Temperatures: 43 to 49 deg. F. 27 to 33 deg. F. 44 to 50 deg. F.
Wind Direction: South to southeast Southwest to west Southwest to west
Wind Speed: up to 10 mph up to 10 mph 10 to 15 mph
Expected snowfall: 0 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