THIS AVALANCHE ADVISORY EXPIRED ON January 14, 2014 @ 7:00 am
Avalanche Advisory published on January 13, 2014 @ 7:00 am
Issued by Andy Anderson - Tahoe National Forest

The avalanche danger has returned to LOW on all snow covered slopes. Human triggered avalanches are unlikely today but not impossible. Some unstable snow may continue to lurk on isolated terrain features. The SE-S-SW-W aspects do not have enough snow cover on them to warrant a danger rating.

1. Low

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Above Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

1. Low

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Near Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

1. Low

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Below Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
    Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
Avalanche Problem 1: Normal Caution
  • Type ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Observations and data collected during and since the storm on Saturday, have indicated that the meager new snow accumulation did very little to change the overall avalanche conditions. The snowpack still contains buried persistent weak layers on the near and below treeline NW-N-NE aspects. In some areas a shrinking snowpack has caused the weak layers to fragment, and they no longer connect across large slopes. In other areas the loss of snow has simply decreased the weight on top of the persistent weak layers. In still other areas, the snow above the buried persistent weak layers has lost strength creating a snowpack with weak snow on top of weak snow with no slab above the weak layers. All of these factors combined have made triggering avalanches unlikely. Unlikely does not mean impossible. Some unstable snow may still lurk on isolated terrain features on NW-N-NE aspects. Use hand pits, pole probes, and other observations to look and feel for stronger higher density snow on top of lower density snow. If this stratigraphy exists, stop and evaluate the weak layer below the slab to see if it could still fracture.

Even though the avalanche danger has deceased, the barely covered rocks, logs, trees, stumps, and other obstacles including areas of bare ground on all aspects still make on-the-snow-recreation challenging. All of these things have become difficult to avoid, and collisions with these things could easily injure a person or break equipment. 

recent observations

Yesterday on Red Lake Peak, observations showed 1 to 3 inches of new snow sitting on top of the ground or a very shallow snowpack on lower elevation slopes. On the N-NE aspects above 8000 ft. the new snow rested on top of a 10 to 24 inch snowpack. The old weak layers still exist in the snowpack, and the whole pack continues to lose strength and facet. On more exposed near treeline N-NE aspects, small 4 to 7 inch deep wind slabs had formed in some areas. General observations, test slope cuts, and snowpit data did not yield unstable results concerning the small wind slabs. The data showed some variable results concerning the buried persistent weak layers; however, most data pointed to a weak but stable snowpack.

Weather and CURRENT CONDITIONS
weather summary

High pressure has returned to the region bringing clear, dry weather for the foreseeable future. The NE and E winds should remain strong today before decreasing overnight and tomorrow. The temperatures should also begin a warming trend with today's highs in the low to mid 40's above 7000 ft. Tomorrow temperatures should climb a little more reaching into the upper 40's and maybe even low 50's above 7000 ft.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 25 to 33 deg. F.
Max. temperature in the last 24 hours: 26 to 35 deg. F.
Average wind direction during the last 24 hours: East Northeast
Average wind speed during the last 24 hours: 25 to 35 mph
Maximum wind gust in the last 24 hours: 75 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 10 to 17 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Monday Monday Night Tuesday
Weather: Sunny Clear Sunny
Temperatures: 42 to 47 deg. F. 25 to 30 deg. F. 44 to 49 deg. F.
Wind Direction: East East East
Wind Speed: 10 to 20 mph with gusts to 30 mph decreasing to 10 to 15 mph in the afternoon 10 to 15 mph with gusts to 25 mph 10 to 15 mph with gusts to 25 mph in the morning
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Monday Monday Night Tuesday
Weather: Sunny Clear Sunny
Temperatures: 37 to 44 deg. F. 22 to 30 deg. F. 40 to 47 deg. F.
Wind Direction: Northeast Northeast East
Wind Speed: 20 to 30 mph with gusts to 50 mph in the morning decreasing to 10 to 20 mph with gusts to 35 mph in the afternoon 15 to 25 mph with gusts to 40 mph 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.