THIS AVALANCHE ADVISORY EXPIRED ON December 5, 2016 @ 6:48 am
Avalanche Advisory published on December 4, 2016 @ 6:48 am
Issued by Andy Anderson - Tahoe National Forest

LOW avalanche danger exists on all aspects and elevations. LOW danger does not mean "no danger" and small avalanches could still occur in isolated areas or extreme terrain. Practice safe backcountry travel habits like moving one at a time from safe zone to safe zone to reduce your risk while traveling through avalanche terrain. Early season conditions exist with numerous exposed and shallowly buried obstacles in most areas.

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
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Avalanche activity remains unlikely today; however, some unstable snow could still exist on isolated terrain features especially in complex or extreme terrain. Small avalanches can have big consequences especially when the snowpack remains shallow. Even though the avalanche danger remains LOW continue to practice safe back-country travel habits. Make a travel plan, discuss it with your group, and share it with someone who will not be on your trip. Continue to evaluate the snowpack and terrain and watch out for those isolated terrain features where unstable snow may remain. When moving into or through potential avalanche terrain, only expose one member of your group at a time. Identify safe zones out of avalanche terrain and re-group in those areas. Practicing these techniques now will make them habits that will serve you well when increased avalanche danger exists.

While LOW avalanche danger means less avalanche hazard, the shallow snowpack means more exposed and shallowly buried obstacles to hit. Collisions with these exposed or barely covered rocks, logs, stumps, trees, and other hard immovable objects can break equipment and people. Enjoy the snow, but be careful so that the enjoyment will last all season long.

advisory discussion

The Sierra Crest north of Tahoe City and the Mt. Rose backcountry harbor the deepest and most usable snowpack within the forecast area. Even in these more snow covered areas early season conditions still persist and many obstacles remain. Along the Sierra Crest south of Tahoe City, the snowpack becomes more shallow with many more exposed and barely covered obstacles even at the upper elevations.

We greatly appreciate all of the recent avalanche and snowpack observations submitted by local users. This data helps us craft better advisories. Please continue to submit observations through the "submit observations" buttons found throughout this website. Remember any information you have can help. Simple weather and snowpack observations like how deep do you sink in the snow,  have you seen any avalanches or signs of instability, did you see snow blowing at the ridgelines are all helpful. Of course, we will take more detailed observations like snowpit data, videos, or photos as well. 

recent observations

Yesterday observations from Grouse Rocks and Red Lake Peak showed widespread wind scouring on the exposed near and above treeline slopes. Wind created surfaces like wind crusts, sastrugi, ripples, etc. existed across a wide variety of aspects and extended into some traditionally sheltered areas. Observations from these areas did not reveal any signs of instability. A snowpit submitted by a Level 1 avalanche class from a lower elevation E facing aspect on Donner Summit showed a shallow snowpack consisting of mostly consolidated snow. 

On a N aspect on Red Lake Peak snowpit data showed a persistent weak layer buried near the base of the snowpack, but tests on this layer indicated that triggering it has become unlikley. While it may not represent a current avalanche problem, it still warrants monitoring to see if it could re-awaken during a future loading event. Persistent weak layers have been found on N aspects along the Sierra Crest above 8300' and in the Mt. Rose area above 9300'. There have been no avalanches associated with these layers.

Weather and CURRENT CONDITIONS
weather summary

This morning temperatures remain colder in the valleys than at the higher elevations due to cold air trapped at the lower elevations. As the southwest winds increase today, expect this inversion to lift. The sunny to partly cloudy skies and warm air moving into the region should allow temperatures to climb into the mid to upper 40's above 7000 ft. today. By tomorrow a dry cold front should impact the region bringing some clouds and a slight chance of isolated snow showers. Tomorrow's highs should fall back into the 30's above 7000 ft.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 31 to 42 deg. F.
Max. temperature in the last 24 hours: 40 to 46 deg. F.
Average wind direction during the last 24 hours: East shifting to WSW after midnight
Average wind speed during the last 24 hours: 15 mph
Maximum wind gust in the last 24 hours: 45 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 9 to 21 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Sunday Sunday Night Monday
Weather: Partly cloudy Mostly cloudy Mostly cloudy with a slight chance of snow showers in the morning becoming partly cloudy in the afternoon
Temperatures: 42 to 48 deg. F. 21 to 26 deg. F. 35 to 41 deg. F.
Wind Direction: Southwest Southwest West
Wind Speed: 10 to 15 mph increasing to 15 to 25 mph with gusts to 45 mph in the afternoon 15 to 20 mph with gusts to 45 mph 10 to 15 mph with gusts to 40 mph
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Sunday Sunday Night Monday
Weather: Partly cloudy Mostly cloudy Mostly cloudy with a slight chance of snow showers in the morning becoming partly cloudy in the afternoon
Temperatures: 41 to 47 deg. F. 19 to 24 deg. F. 32 to 38 deg. F.
Wind Direction: West West West
Wind Speed: 20 to 30 mph with gusts to 50 mph increasing to 70 mph in the afternoon 20 to 35 mph with gusts to 85 mph decreasing to 65 mph after midnight 20 to 30 mph with gusts to 70 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