THIS AVALANCHE ADVISORY EXPIRED ON March 10, 2016 @ 6:52 am
Avalanche Advisory published on March 9, 2016 @ 6:52 am
Issued by Steve Reynaud - Tahoe National Forest

Moderate avalanche danger exists due to the possibility of wind slabs and loose wet avalanches.  Ongoing SW winds could continue to build wind slabs on NW-N-NE-E-SE aspects near and above treeline.  Loose wet avalanches will become possible throughout the day as temperatures warm and snow levels increase on all aspects below treeline.  Evaluate snow and terrain carefully, identify areas of concern.

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: Wind Slab
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Strong SW winds above 8000' through today will continue wind slab development on NW-N-NE-E-SE aspects near and above treeline on slopes steeper than 35 degrees.  There was plenty of snow yesterday available for transport on windward slopes for ongoing wind slabs to form.  In some areas, these winds slabs could form on top of existing wind slabs from the last couple days that have not fully bonded and gained strength. 

Identify and avoid steep wind loaded slopes.  Look for areas of blowing snow, cornice formation, wind scouring, and wind pillows to help determine where wind slabs exist.

Avalanche Problem 2: Loose Wet
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Loose wet avalanches will become possible on all aspects below treeline today as temperatures warm and snow levels rise.  Snow level is forecasted to rise to 7500' by 11am with light precipitation.  Most loose wet instabilities should be in the form of roller balls and pinwheels.  If we receive more rain than expected or rain levels go to higher elevations, loose wet avalanches could become more widespread and larger in size.

Avoid slopes that are steeper than 35 degrees or have terrain above that is 35 degrees as warming occurs in the late morning.  Active roller balls and pinwheels are indications that the snow surface is loosing strength and it's time to get off steeper terrain.

recent observations

We made or received observations yesterday from Castle Peak (Donner Summit area), Jakes Peak (West Shore area), NW of Estelle Bowl (Five Lakes area), Hell Hole (Luther Pass area), and Andesite Peak (Donner Summit area).  Most areas experienced rapid warming with increased solar radiation in the mid morning hours before cloud cover and SW winds increased by mid day.  Blowing snow was visible with active wind loading on Freel Peak, in the higher peaks of Desolation Wilderness, and in the Five Lakes area by mid day.  Light snow began to fall in most areas by 1pm.  Small wet point releases were observed on Jakes Peak on SE-S aspects during the morning hours with full sun.  Little other instabilities were observed as the recent storm snow continues to gain strength. 

Weather and CURRENT CONDITIONS
weather summary

A weak disturbance will bring light snow and rain to the forecast area today.  Snow levels will rise throughout the morning and should top out around 7500' by mid day.  Precipitation should diminish and begin to leave the area by mid afternoon.  SW winds will be strong above 8000' with gusts up to 60mph and increasing into tonight.  Periods of rain and snow will be possible through this weekend and into early next week.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 29 to 32 deg. F.
Max. temperature in the last 24 hours: 40 deg. F.
Average wind direction during the last 24 hours: SW
Average wind speed during the last 24 hours: 25 to 30 mph
Maximum wind gust in the last 24 hours: 56 mph
New snowfall in the last 24 hours: Trace to 2 inches
Total snow depth: 75 to 108 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Wednesday Wednesday Night Thursday
Weather: Cloudy then becoming mostly cloudy. Showers in the morning then isolated showers in the afternoon. Mostly cloudy. Slight chance of showers in the evening. Mostly cloudy then becoming cloudy. Slight chance of showers in the morning then chance of showers in the afternoon.
Temperatures: 39 to 46 deg. F. 28 to 35 deg. F. 40 to 47 deg. F.
Wind Direction: SW SW SW
Wind Speed: 15 to 25mph with gusts to 40mph. 25 to 30mph with gusts to 45mph increasing to 40 to 45mph with gusts to 70mph after midnight. 35 to 45mph with gusts to 70mph.
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Wednesday Wednesday Night Thursday
Weather: Cloudy then becoming mostly cloudy. Snow showers in the morning then isolated snow showers in the afternoon. Mostly cloudy. Mostly cloudy then becoming cloudy. Slight chance of snow showers in the morning then chance of snow in the afternoon.
Temperatures: 34 to 41 deg. F. 27 to 34 deg. F. 37 to 44 deg. F.
Wind Direction: W SW SW
Wind Speed: 25 to 35mph with gusts to 60mph. 30 to 35mph with gusts to 55mph increasing to 60 to 65mph with gusts to 95mph. 65 to 75mph with gusts to 110mph.
Expected snowfall: Up to 2 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.