THIS AVALANCHE ADVISORY EXPIRED ON April 3, 2016 @ 6:47 am
Avalanche Advisory published on April 2, 2016 @ 6:47 am
Issued by Andy Anderson - Tahoe National Forest

MODERATE avalanche danger will quickly form on slopes steeper than 35 degrees on E-SE-S-SW-W aspects at all elevations and may form on some sun-exposed near and below treeline NW-N-NE aspects as daytime warming makes loose wet avalanches possible again today. Evaluate snow and terrain carefully. Identify and avoid the areas where wet snow deep enough for loose wet avalanches exists.

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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    Very Likely
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    Large
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Another day of warm temperatures, plentiful April sunshine, and light winds will quickly melt through the weak refreeze that may have occurred in some places last night. Once this refreeze melts, deep wet snow will exist on many slopes, and loose wet avalanches will become possible again today. While most of these loose wet avalanches should manifest as small point releases, roller balls, or pinwheels, some of the loose wet avalanches that occur today could entrain enough snow to cause problems for backcountry travelers especially in areas where the loose wet avalanches involve terrain traps. The size of loose wet snow instabilities will depend on the amount of recent snow that exists in a specific area. Expect to find deeper wet snow and larger more widespread wet snow issues in the Mt. Rose backcountry where the most snow fell during the recent storm. In areas along the Sierra Crest south of Highway 50 where less recent snow exists, most of the wet snow issues should remain smaller and entrain less snow. Wet snow instabilities in areas north of Highway 50 along the Sierra Crest and on the east side of Lake Tahoe south of Mt. Rose should fall somewhere between the other two zones. Slopes steeper than 35 degrees on sun-exposed E-SE-S-SW-W aspects at all elevations will hold the best potential for loose wet avalanches since they should experience the most warming, but some of the near and below treeline NW-N-NE aspects could also see enough sun for some wet snow instabilities to form. 

Sinking into wet snow above your boot tops and small surface instabilities like roller balls, pinwheels, or point releases can provide clues that enough wet snow has formed for larger loose wet avalanches to become an issue. Moving to more frozen slopes or onto lower angle slopes off and away from slopes 35 degrees or steeper before deep wet snow exists on a slope represents a wise choice today. Terrain traps like gullies, creeks, and cliffs can greatly increase the risk of any size loose wet avalanches.

recent observations

Yesterday 2-3 inches of wet corn snow existed on top of a supportable melt-freeze crust on the SW aspects of Castle Peak by 11 am. The SE-E aspects already held wet sticky snow on a barely supportable crust by that time, and small skier triggered loose wet instabilities had started to occur on steep previously-wind-loaded test slopes where more recent snow existed on the snow surface. Northerly aspects below 8000 ft. also held wet sticky snow on any sun-exposed slopes by 11 am in this area yesterday.  

Weather and CURRENT CONDITIONS
weather summary

Inversion conditions exist across the forecast area with lower elevation sensors reporting overnight lows in the upper 20's to low 30's and upper elevation sensors registering overnight temperatures in the upper 30's and low 40's. The forecast calls for more warm and dry weather across the region due to the high pressure ridge parked over the area. Some cloud cover may start to develop this afternoon as a small low pressure trough passes to the north of the forecast area, but skies should remain mostly sunny for much of the day today and tomorrow. This small system should also cause a light southwest wind across the region this afternoon through tomorrow. Daytime highs will remain well above normal with temperatures climbing into the upper 40's to mid 50's above 7000 ft. today and tomorrow. 

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 36 to 43 deg. F.
Max. temperature in the last 24 hours: 45 to 55 deg. F.
Average wind direction during the last 24 hours: Variable
Average wind speed during the last 24 hours: 5 to 10 mph
Maximum wind gust in the last 24 hours: 21 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 73 to 115 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Saturday Saturday Night Sunday
Weather: Sunny with some clouds in the afternoon Mostly clear with a few clouds after midnight Sunny becoming partly cloudy
Temperatures: 49 to 56 deg. F. 26 to 33 deg. F. 48 to 55 deg. F.
Wind Direction: Variable Southwest West
Wind Speed: Light 10 to 15 mph in the evening becoming light overnight Light winds in the morning increasing to 10 to 15 mph with gusts to 25 mph in the afternoon
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Saturday Saturday Night Sunday
Weather: Sunny with some clouds in the afternoon Mostly clear with a few clouds after midnight Sunny becoming partly cloudy
Temperatures: 44 to 51 deg. F. 25 to 32 deg. F. 43 to 50 deg. F.
Wind Direction: Southwest Southwest Southwest
Wind Speed: 10 to 15 mph 10 to 15 mph with gusts to 25 mph in the evening 15 to 20 mph with gusts to 30 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