THIS AVALANCHE ADVISORY EXPIRED ON March 9, 2016 @ 6:56 am
Avalanche Advisory published on March 8, 2016 @ 6:56 am
Issued by Steve Reynaud - Tahoe National Forest

Early this morning, moderate avalanche danger exists on all aspects and elevations due to the continuing possibility of wind slabs and storm slabs.  As sunny skies and solar radiation affect the snowpack later this morning, avalanche danger will rise to considerable on E-SE-S-SW-W aspects due to loose wet avalanches and the possibility of wet slabs.  Increasing SW-W winds throughout the day will form new wind slabs on NW-N-NE-E-SE-S aspects near and above treeline. 

3. Considerable

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Above Treeline
Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.

3. Considerable

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Near Treeline
Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.

3. Considerable

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Below Treeline
Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
    Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
Avalanche Problem 1: Wind Slab
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Winds switched to the NE overnight and are now back to the SW and increasing in speed.  Winds are forecasted to be from the SW/W in the 30 to 35mph range with gusts to 50mph in the afternoon.  With significant amounts of snow available for transport, wind slabs could form on NW-N-NE-E-SE and maybe even S aspects near and above treeline during the day.  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.

In the areas of direct wind loading later today, natural avalanches could become possible and human triggered wind slabs could become likely.  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 likely today on E-SE-S-SW-W aspects as daytime warming occurs with intense solar radiation.  Most loose wet instabilities will be in the form of roller balls and pinwheels.  Though larger loose wet avalanches that are large enough to injure or bury a backcountry user will become possible today.

Avoid slopes that are steeper than 35 degrees or have terrain above that is 35 degrees as solar radiation increases.  Timing is critical on solar aspects as danger can increase quickly.  Wet surface snow, active roller balls and pinwheels are indications that the snow surface is loosing strength and it's time to get off steeper terrain and change aspects.  

Avalanche Problem 3: Wet Slab
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Wet slabs will become possible today on E-SE-S-SW-W aspects at all elevations.  Most wet instabilities today are expected to be in the form of loose wet avalanches but there is the possibility that wet slabs could occur.  These wet slabs could fail on previous wind slabs and storm slabs that have not fully bonded and gained strength or new wind slabs that are forming today.

Today will be the first significant melt on our new storm snow.  Cloud cover could play a part this afternoon by limiting or increasing the amount of solar radiation slopes receive.  Avoid steep slopes on solar aspects.  Loose wet avalanches could occur just prior to wet slab activity. 

recent observations

A skier triggered avalanche was reported above the Red Lake Road (Carson Pass area) yesterday around 12pm.  Crown was 1' deep and failed within the recent storm snow.  Other details are not available at this time.

Other observations from Rubicon Peak (West Shore area), Angora Peak (Echo Summit area), Echo Peak (Echo Summit area), and Elephants Hump (Carson Pass area) reported 2-4' of recent storm snow with additional snowfall in the afternoon.  In many locations shooting cracks and some snowpack tests indicated that there is still weakness within the recent storm snow.  Humid conditions with wet sticky snow below 7000' was reported. 

Weather and CURRENT CONDITIONS
weather summary

A shortwave ridge will bring dry and sunny conditions to our forecast area today before another chance of rain/snow showers possible starting tonight.  Clouds are forecasted to increase into this afternoon with winds swifting to the W at 30 to 35mph with gusts to 50mph above 8000'.  Remote sensors reporting temperatures at 6am this morning in the high teens to low 20's.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 16 to 21 deg. F.
Max. temperature in the last 24 hours: 37 deg. F.
Average wind direction during the last 24 hours: NE shifting to SW
Average wind speed during the last 24 hours: 20 to 25 mph
Maximum wind gust in the last 24 hours: 38 mph
New snowfall in the last 24 hours: 2 to 4 inches
Total snow depth: 78 to 110 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Tuesday Tuesday Night Wednesday
Weather: Sunny then becoming mostly cloudy. Cloudy. Slight chance of snow in the evening then chance of snow after midnight. Cloudy. Chance of rain and snow in the morning, then slight chance of rain and snow in the afternoon.
Temperatures: 33 to 40 deg. F. 23 to 30 deg. F. 39 to 46 deg. F.
Wind Direction: SW SW SW
Wind Speed: 15 to 25mph with gusts to 35mph. 20 to 30mph with gusts to 50mph. 25 to 35mph with gusts to 50mph.
Expected snowfall: 0 in. Up to 1 in. Up to 2 in.
For 8000 ft. to 9000 ft.
Tuesday Tuesday Night Wednesday
Weather: Sunny then becoming mostly cloudy. Cloudy. Slight chance of snow this evening then chance of snow after midnight. Cloudy. Chance of snow in the morning then slight chance of rain and snow in the afternoon.
Temperatures: 30 to 37 deg. F. 22 to 29 deg. F. 36 to 43 deg. F.
Wind Direction: SW to W W W
Wind Speed: 20 to 25mph with gusts to 40mph increasing to West 30 to 35mph with gusts to 50mph. 40 to 50mph with gusts to 75mph. 35 to 45mph with gusts to 60mph increasing to 70mph in the afternoon.
Expected snowfall: 0 in. Up to 1 in. Up to 3 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.