THIS AVALANCHE ADVISORY EXPIRED ON December 19, 2017 @ 6:50 am
Avalanche Advisory published on December 18, 2017 @ 6:50 am
Issued by Steve Reynaud - Tahoe National Forest

Low avalanche danger continues throughout the forecast area at all elevations.  While triggering an avalanche is unlikely, you should still follow safe travel protocols when in and around avalanche terrain.  Normal caution is advised.

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

Triggering an avalanche is unlikely today, but there are a couple things to be aware of.  Hard wind slabs on top of weaker, faceted snow exist in some isolated areas on NW-N-NE aspects in near and above treeline terrain.  Soft slabs on top of weaker faceted snow could exist in isolated areas on NW-N-NE aspects in below treeline terrain and have been found in the southern part of the forecast region.

Firm snow surfaces exist in many wind exposed areas.  A fall or a slip could be hard to arrest in steeper terrain.  Early season snowpack conditions continue in most areas with many obstacles and hazards present.  Normal caution is advised while traveling in the backcountry.

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

Calm weather is expected today and into Tuesday.  A fast moving cold front is forecasted for Tuesday night into Wednesday with increasing winds and snow to all elevations.  Limited moisture with this cold storm is forecasted to produce around 3 to 6'' for the mountains.  SW wind gusts over ridges are forecasted to be in excess of 100mph Tuesday night.  A high wind watch is in effect for Tuesday night through Wednesday morning for our forecast area.  Dry and cold conditions will return after this storm with a NE flow on Thursday and Friday. 

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: 43 deg. F.
Average wind direction during the last 24 hours: NE
Average wind speed during the last 24 hours: 15 to 40 mph
Maximum wind gust in the last 24 hours: 84 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 16 to 32 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Monday Monday Night Tuesday
Weather: Partly cloudy Partly cloudy Partly cloudy
Temperatures: 40 to 45 deg. F. 21 to 27 deg. F. 45 to 50 deg. F.
Wind Direction: SW
Wind Speed: Light winds Light winds 10 to 15mph with gusts to 30mph increasing to 20 to 30mph with gusts to 60mph in the afternoon.
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Monday Monday Night Tuesday
Weather: Partly cloudy Partly cloudy Partly cloudy
Temperatures: 37 to 42 deg. F. 22 to 27 deg. F. 42 to 47 deg. F.
Wind Direction: N N shifting to W W shifting to SW
Wind Speed: 10 to 15mph with gusts to 25mph in the morning becoming light. 10 to 15mph with gusts to 30mph shifting to the W with gusts up to 40mph after midnight. 20 to 30mph with gusts to 50mph increasing to SW 30 to 45mph with gusts to 90mph 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