THIS AVALANCHE ADVISORY EXPIRED ON March 4, 2017 @ 6:59 am
Avalanche Advisory published on March 3, 2017 @ 6:59 am
Issued by Andy Anderson - Tahoe National Forest

Loose wet avalanches will become possible at all elevations as the day warms up. The avalanche danger will rise to MODERATE at all elevations today. Other lingering avalanche problems may also still exist like the large cornices above many slopes or instabilities on isolated terrain features in complex or extreme terrain. Identify terrain where avalanche problems may exist and use this information to plan a travel route that avoids the problematic terrain.

2. Moderate

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

2. Moderate

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

2. Moderate

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Below Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
    Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
Avalanche Problem 1: Loose Wet
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Continued warmth and sunshine today will keep loose wet avalanches as an avalanche problem on slopes where the snow becomes warm and wet especially on sun-exposed E-SE-S-SW-W aspects. As cloud cover increases this afternoon, loose wet instability may become less widespread. However, the clouds could act as a blanket to distribute the warmth to the northerly aspects where some small loose wet instabilities may begin to form on slopes below 8000 ft.  Roller balls, pinwheels, and wet point release avalanches could occur today. Many of these should remain small, but some of them could entrain enough snow to knock a person or machine off balance or push them off course into more consequential terrain. 

As the day warms up, pay attention to where small loose wet instabilities occur and where wet snow forms and avoid steep slopes on those aspects.

Avalanche Problem 2: Cornice
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Large cornices that could break well away from their edges under the weight of a person on top of them exist along many ridgelines across the forecast area. While their failure is unlikely to trigger a wind slab avalanche below them except in isolated areas in complex or extreme terrain, they are large enough to cause problems on their own. Give these cornices a wide berth and stay well away from their edges. 

recent observations

Yesterday a small skier-triggered avalanche occurred in the complex terrain in the north bowl of Castle Peak. This 6-inch deep slab avalanche was likely a leftover wind slab from the recent storm. It buried the skier who triggered it waist deep but did not injure him. In other areas including Secret Peak on the West Shore, Becker/Talking Mountain on Echo Summit, and Rose Knob Peak no signs of lingering wind slab instability existed on northerly aspects. On the E-SE-S-SW aspects in these areas, numerous small loose wet avalanches occurred both naturally near rocks and cliffs as well as in response to ski cuts on steep slopes. In the Echo summit area and on Genoa Peak near Spooner Summit widespread surface hoar existed on many slopes. 

Weather and CURRENT CONDITIONS
weather summary

The forecast calls for another warm day across the forecast area with daytime highs in the upper 40's above 7000 ft. again today. Some high thin clouds have already made their way into the region and the southwest winds have started to increase. Cloud cover should become more widespread and the winds should continue to increase today ahead of a storm system expected to arrive over the forecast area tomorrow afternoon/evening. The forecast calls for much colder temperatures tomorrow and up to 2 inches of snow in the afternoon. The bulk of this storm should impact the region tomorrow night and into Sunday. For more information on the upcoming storm check in with the Reno NWS. 

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 27 to 37 deg. F.
Max. temperature in the last 24 hours: 44 to 51 deg. F.
Average wind direction during the last 24 hours: Southwest
Average wind speed during the last 24 hours: 5 to 15 mph
Maximum wind gust in the last 24 hours: 25 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 132 to 181 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Friday Friday Night Saturday
Weather: Partly cloudy becoming mostly cloudy Mostly cloudy Mostly cloudy with snow likely in the afternoon
Temperatures: 44 to 49 deg. F. 27 to 31 deg. F. 34 to 40 deg. F.
Wind Direction: Southwest Southwest Southwest
Wind Speed: Light in the morning increasing to 10 to 15 mph with gusts to 35 mph in the afternoon 10 to 15 mph with gusts to 35 mph increasing to gusts to 50 mph after midnight 15 to 25 mph with gusts to 50 mph increasing to 20 to 35 mph with gusts to 65 mph in the afternoon
Expected snowfall: 0 in. 0 in. up to 1 in.
For 8000 ft. to 9000 ft.
Friday Friday Night Saturday
Weather: Partly cloudy becoming mostly cloudy Mostly cloudy Mostly cloudy with snow likely in the afternoon
Temperatures: 37 to 44 deg. F. 23 to 27 deg. F. 28 to 34 deg. F.
Wind Direction: Southwest Southwest Southwest
Wind Speed: 10 to 15 mph with gusts to 30 mph increasing to 20 to 30 mph with gusts to 65 mph in the afternoon 30 to 45 mph with gusts to 85 mph 30 to 50 mph with gusts to 90 mph
Expected snowfall: 0 in. 0 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