THIS AVALANCHE ADVISORY EXPIRED ON March 27, 2016 @ 7:00 am
Avalanche Advisory published on March 26, 2016 @ 7:00 am
Issued by Andy Anderson - Tahoe National Forest

MODERATE avalanche danger will form on slopes steeper than 35 degrees on E-SE-S-SW-W aspects at all elevations and may form on some near and below treeline NW-N-NE aspects as loose wet avalanches become possible today. Some loose wet snow avalanches could entrain enough snow to pose a threat to backcountry travelers. Once deep wet snow exists on a slope, it is time to move to more frozen aspects, onto lower angle slopes, or to switch to a different afternoon activity.

2. Moderate

?

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

2. Moderate

?

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

2. Moderate

?

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
  • Type ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Several loose wet avalanches that entrained enough snow to carry a person down slope and maybe bury or injure a person have occurred in the last few days. These kind of loose wet avalanches will become possible again today as the strong March sunshine and warm daytime temperatures melt through last night's refreeze. Since temperatures remained well below freezing last night, a stronger refreeze that may take slightly longer to melt should have occurred. Most of the loose wet instabilities that do occur today should consist of small roller balls, pinwheels, and point releases, but some larger loose wet avalanches similar to those in the recent observations that entrain enough snow to cause problems for backcountry travelers could still occur. 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 mid to lower elevation 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 loose wet avalanches to become an issue. When the last night's refreeze melts and the snowpack becomes unsupportable, it is time to move to more frozen slopes or onto lower angle slopes off and away from slopes 35 degrees or steeper. Terrain traps like gullies, creeks, and cliffs can greatly increase the risk of any size loose wet avalanches.

recent observations

At least 2 skier triggered loose wet avalanches that entrained enough snow to carry a person down slope occurred in the backcountry around Emerald Bay before 1pm yesterday. One of them occurred on a E-ENE facing aspect west of Emerald Bay, and one occurred on the E facing path on Jake's. We observed these slides from the road and do not have any other details on them. Another larger loose wet avalanche that likely occurred on March 24 had occurred in one of the S facing chutes on Jakes. This slide looked to have released naturally on a 37 degree slope, and it slid about 400 ft. down slope.

Yesterday 2 to 4 inches of wet snow had formed above a thin melt freeze crust on the south side of Jake's Peak by 11 am. This crust remained supportable until around noon and it appeared that it would soon melt all the way through at that time. Skier triggered loose wet roller balls occurred on E facing slopes. North facing upper elevation slopes held a mix of softer snow and thin crusts. 

Weather and CURRENT CONDITIONS
weather summary

After a cold clear night with overnight lows in the 20's at most elevations, the forecast calls for more sunny skies and warm weather today. Expect daytime highs in the upper 40's above 7000 ft. today. Light east winds should persist through the day before decreasing and shifting to the west tonight. Temperatures tomorrow should be slightly cooler than today, and cloud cover and winds should start to increase tomorrow ahead of a small cold storm moving towards the region.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 23 to 28 deg. F.
Max. temperature in the last 24 hours: 43 to 48 deg. F.
Average wind direction during the last 24 hours: Southwest to northeast
Average wind speed during the last 24 hours: 10 to 20 mph
Maximum wind gust in the last 24 hours: 30 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 78 to 118 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 Partly cloudy Partly cloudy becoming mostly cloudy
Temperatures: 43 to 50 deg. F. 26 to 31 deg. F. 41 to 48 deg. F.
Wind Direction: East Variable Southwest
Wind Speed: 10 to 15 mph with gusts to 25 mph becoming light in the afternoon Light 10 to 15 mph increasing to 20 to 25 mph with gusts to 40 mph in the afternoon
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Saturday Saturday Night Sunday
Weather: Sunny Partly cloudy Partly cloudy becoming mostly cloudy
Temperatures: 39 to 44 deg. F. 24 to 31 deg. F. 35 to 42 deg. F.
Wind Direction: Southeast West Southwest
Wind Speed: 15 to 20 mph with gusts to 30 mph in the morning 10 to 15 mph with gusts to 25 mph after midnight 15 to 20 mph with gusts to 30 mph increasing to 35 to 40 mph with gusts to 55 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.

For a recorded version of the Avalanche Advisory call (530) 587-3558 x258