THIS AVALANCHE ADVISORY EXPIRED ON December 7, 2015 @ 6:59 am
Avalanche Advisory published on December 6, 2015 @ 6:59 am
Issued by Brandon Schwartz - Tahoe National Forest

LOW avalanche danger continues for all elevations and aspects. Small isolated pockets of unstable snow may exist. Normal caution is advised. It is still early season with generally shallow snow coverage and numerous poorly covered obstacles to hit.

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

Overall good snowpack stability has been observed around the forecast area. Any instability issues are most likely to be associated with lower density snow that lingers at the base of the snowpack near treeline and below treeline on NW-N-NE aspects. In areas where this snow has been observed at its weakest over the past few days it has been on slopes that are well anchored. There is lots of micro terrain within the forecast area so the possibility of finding that one spot where all of the factors of weak snow, poor anchoring, and sufficiently steep terrain all coexist remains within the realm of possibility. Stack the odds in the favor of best possible outcomes by using normal caution. Expose only one person at a time when in or below avalanche terrain, don't rely on marginal quality islands of safety, and avoid grouping up in avalanche runout zones.

Minimal amounts of new snow today over the northern portion of the forecast area is not expected to create new avalanche problems.

recent observations

Overall the snowpack has shown indications of increasing stability over the past few days in observations and recent snowpit data gathered from the Carson Pass, West Shore Tahoe, Pole Creek, and Mount Rose areas. Warming before the last storm helped to settle and increase bonding within the deeper snow layers. Post storm the recent new snow has appeared to bond well to the old snow layers. Isolated areas where the snowpack structure remains concerning with a lower density layer at the base of the snowpack near treeline and below treeline on NW-N-NE aspects are generally well anchored. In the vast majority of areas this lower density layer that was once well developed facets is now fairly well rounded. In isolated pockets, this lower density layer has retained some loose grained, faceted characteristics.

Weather and CURRENT CONDITIONS
weather summary

A weather system passing by to the north of the forecast area has increased winds overnight. Strong to gale force SW winds are blowing over the ridgetops this morning and are forecast to continue through this evening. Wind will be the big weather story today with most of the significant precipitation well to the north of the forecast area. Light precipitation is possible mainly north of I-80 with generally a trace to a remote possibly of up to 2 inches of snowfall expected. Snow levels are forecast to begin around 5,000' and then rise as the day progresses. In the big picture, the overall warming trend is expected to continue for the next few days with westerly atmospheric flow and maximum daytime air temperatures above 7,000' in the mid 30s to mid 40s today and low to upper 40s tomorrow. Confidence is increasing that a series of storm systems will impact the forecast area later this week.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 27 to 36 deg. F.
Max. temperature in the last 24 hours: 36 to 41 deg. F.
Average wind direction during the last 24 hours: SW
Average wind speed during the last 24 hours: 36 mph
Maximum wind gust in the last 24 hours: 74 mph
New snowfall in the last 24 hours: 0 to trace inches
Total snow depth: 17 to 23 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Sunday Sunday Night Monday
Weather: Mostly cloudy skies with scattered snow showers. Partly cloudy skies, becoming mostly cloudy. Mostly cloudy skies.
Temperatures: 37 to 44 deg. F. 25 to 33 deg. F. 42 to 49 deg. F.
Wind Direction: SW SW SW
Wind Speed: 30 to 40 mph with gusts to 60 mph. 20 to 30 mph with gusts to 45 mph. Gusts decreasing to 35 mph after midnight. 15 to 25 mph with gusts to 35 mph.
Expected snowfall: 0 to 2 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Sunday Sunday Night Monday
Weather: Mostly cloudy skies with scattered snow showers. Partly cloudy skies, becoming mostly cloudy. Mostly cloudy skies.
Temperatures: 34 to 41 deg. F. 27 to 33 deg. F. 40 to 47 deg. F.
Wind Direction: SW SW SW
Wind Speed: 55 to 60 mph with gusts to 90 mph, decreasing to 45 to 50 mph with gusts to 70 mph in the afternoon. 30 to 40 mph with gusts to 60 mph. 25 to 35 mph with gust to 50 mph. Gusts decreasing to 40 mph in the afternoon.
Expected snowfall: 0 to 2 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.