THIS AVALANCHE ADVISORY EXPIRED ON April 11, 2013 @ 6:39 am
Avalanche Advisory published on April 10, 2013 @ 6:39 am
Issued by Andy Anderson - Tahoe National Forest

This morning the avalanche danger is LOW. As the day warms up, small pockets of MODERATE avalanche danger may form on E-SE-S-SW-W aspects on slopes 35 degrees and steeper due to daytime warming creating small shallow wet snow instabilities.

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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    Certain
    Very Likely
    Likely
    Possible
    Unlikely
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    Historic
    Very Large
    Large
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Warm sunny weather will create wet snow on the sun exposed E-SE-S-SW-W aspects today. Some wet snow instabilities like roller balls, pinwheels, and wet point releases may form on these aspects especially in areas near exposed rocks or trees. The continued northerly winds should help limit these wet snow instabilities. They should also remain shallow and only involve the new snow. Even though these loose wet avalanches should remain too small to bury a person, they could still push a person into an area with other consequences or could become more serious in areas where terrain traps exist. Wet slab avalanches remain unlikely today; however, they are not impossible. In the unlikely event a wet slab did occur, it should also remain shallow and only involve the new snow.

recent observations

Yesterday observations on Incline Lake Peak (photo, more info) revealed widespread wind scouring at all elevations on N-NE-E aspects. Even on the below treeline sheltered slopes the strong NE winds had exposed old crusts in some areas. In the most sheltered areas some patches of softer snow still remained. The winds had completely scoured the new snow away from the more exposed near and above treeline N-NE slopes. On the SW-S-SE aspects wind slabs that did not extend very far downslope did exist. Snowpit tests on these wind slabs did not reveal signs of instability.

Weather and CURRENT CONDITIONS
weather summary

As the high pressure ridge becomes more established over the region today, temperatures could climb into the the upper 40's and mid 50's above 7000 ft. The northerly winds should also begin to decrease. The warm sunny weather expected today should give way to a few clouds and a slight chance of some very light showers tomorrow morning as a small weak cold front passes near the area. The forecast calls for daytime highs a few degrees cooler tomorrow.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 26-33 deg. F.
Max. temperature in the last 24 hours: 29-39 deg. F.
Average wind direction during the last 24 hours: Northeast
Average wind speed during the last 24 hours: 30-45 mph
Maximum wind gust in the last 24 hours: 80 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 46-84 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Wednesday Wednesday Night Thursday
Weather: Sunny Partly cloudy becoming mostly cloudy Mostly cloudy with a slight chance of showers in the morning. Becoming partly cloudy in the afternoon
Temperatures: 50-57 deg. F. 32-36 deg. F. 44-52 deg. F.
Wind Direction: Northeast shifting to the north West West shifting to the east
Wind Speed: 15-25 mph with gusts to 35 mph decreasing to 10-20 mph in the afternoon 15-20 mph with gusts to 30 mph 15-20 mph with gusts to 30 mph
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Wednesday Wednesday Night Thursday
Weather: Sunny Partly cloudy becoming mostly cloudy Mostly cloudy with a slight chance of showers in the morning. Becoming partly cloudy in the afternoon
Temperatures: 45-50 deg. F. 28-33 deg. F. 39-44 deg. F.
Wind Direction: Northeast shifting to the north in the afternoon West West shifting to the east in the afternoon
Wind Speed: 35-40 mph with gusts to 60 mph decreasing to 15-25 mph with gusts to 40 mph in the afternoon 20-30 mph with gusts to 45 mph 25-30 mph with gusts to 50 mph decreasing to 15-20 mph with gusts to 30 mph in the afternoon
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.