THIS AVALANCHE FORECAST EXPIRED ON December 18, 2017 @ 6:50 am
Avalanche Forecast published on December 17, 2017 @ 6:50 am
Issued by Steve Reynaud - Tahoe National Forest

Low avalanche danger continues throughout the forecast region.  Normal caution is advised.  Watch for unstable snow on isolated terrain features at all elevations .

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
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  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
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    Very Large
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    Small

Snowpack tests continue to point to isolated areas of instabilities throughout the forecast region.  Hard wind slabs on top of weak faceted snow remain a concern in near and above treeline terrain on NW-N-NE aspects.  Below treeline on NW-N-NE aspects, soft slabs on top of weak faceted snow have been observed on the southern half of the forecast area.  Our shallow and variable snowpack continues to weaken and facet with the current weather of mostly clear skies and no additional storms. 

Strong to gale force NE winds will continue to transport minor amounts of snow today before decreasing in speed later this afternoon.  With limited amounts of snow available for transport, wind slab development is expected to be small.

Firm and variable snow surfaces exist in most areas near and above treeline.  Use normal caution when traveling in or near avalanche terrain.

recent observations

* Snowpack tests continue to point to isolated areas of instabilities throughout the forecast region.  Hard wind slabs over weak faceted snow in near treeline and above treeline terrain and soft slabs over weak faceted snow in below treeline terrain.

* Widespread firm, wind scoured snow surfaces exist on most aspects near and above treeline.

* Variable snow surfaces with some areas of softer snow exist near and below treeline in shaded, wind protected areas.

* Areas north of Emerald Bay above 8,000', hold decent snow coverage. Below 8,000' snow coverage remains patchy and shallow. South of Emerald Bay, less snow exists with areas below 8,500' holding very little snow.

* Snow coverage on southerly aspects has decreased due to melt throughout the forecast area.

Weather and CURRENT CONDITIONS
weather summary

NE wind gusts have been over 100mph on area ridges and peaks during the last 24 hours.  These winds will begin to decrease today as ridging builds into the area.  Warming temperatures with sunny to partly cloudy skies are forecasted for the early part of this week.  A cold front is expected for Wednesday with light snow possible and increasing winds.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 12 to 23 deg. F.
Max. temperature in the last 24 hours: 28 deg. F.
Average wind direction during the last 24 hours: NE
Average wind speed during the last 24 hours: 40 to 80 mph
Maximum wind gust in the last 24 hours: 112 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 15 to 32 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Sunday Sunday Night Monday
Weather: Sunny Clear then becoming partly cloudy. Partly cloudy.
Temperatures: 33 to 38 deg. F. 22 to 28 deg. F. 40 to 45 deg. F.
Winds: E NE
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Sunday Sunday Night Monday
Weather: Sunny Clear then becoming partly cloudy. Partly cloudy.
Temperatures: 31 to 36 deg. F. 23 to 28 deg. F. 37 to 42 deg. F.
Winds: E NE N
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