THIS AVALANCHE FORECAST EXPIRED ON December 30, 2018 @ 6:46 am
Avalanche Forecast published on December 29, 2018 @ 6:46 am
Issued by Brandon Schwartz - Tahoe National Forest

Avalanche danger is LOW for all elevations. Difficult to trigger wind slabs exist in recently wind loaded areas, mainly near treeline and above treeline. Human triggered avalanches are unlikely today but not impossible.

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: Wind Slab
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Drifting snow has diminished. NE wind speeds have decreased and snow available for transport has become limited. Difficult to trigger wind slabs exist in a variety of areas. The majority of wind slabs exist near treeline and above treeline on S-SW-W-NW aspects, but look for them in other wind exposed areas. Firm wind slabs that sit on top of weak, faceted snow are the most suspect. Avalanche size up to D2 is possible (large enough to bury or injure a person).

Look for unstable snow in isolated areas. Identify suspect areas where recently wind drifted snow has deposited using clues such as wind pillows and firm, textured snow surfaces. The unlikely human triggered avalanche could be a bit of a surprise today, so avoid being lulled into a sense of security and complacency. Keep a substantial margin of safety by employing best practices for travel in avalanche terrain (see Bruce Tremper's "Ten Commandments of Low-Risk Travel").

recent observations
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* NE winds were observed to create areas of drifting snow yesterday morning in near treeline and above treeline areas.

* Small wind slabs have been observed on numerous aspects in wind exposed areas, mainly near treeline and above treeline. In some areas these wind slabs sit on top of weak faceted snow.

* The snowpack continues to facet in many locations, especially on northerly aspects that hold a shallow snowpack. This remains a monitoring concern up to the next new snow loading event.

Weather and CURRENT CONDITIONS
weather summary

Air temperature inversion conditions set up early this morning with the coldest air temperatures on the mountain valley floors. NE winds remained moderate to strong in speed for the past 24 hours and are expected to continue at moderate speed through today. Ridgetop winds are forecast to shift to the NW tonight. This wind shift may mix out the inversion and allow for a short lived bit of warming tomorrow. Another cold front will impact the forecast area Sunday night with a dusting of snow possible.

CONDITIONS ALONG THE SIERRA CREST BETWEEN 8200 FT. AND 9200 FT. IN THE LAST 24 HOURS
Weather Station Map
Weather Station Table
6am temperature: 18 to 27 deg. F.
Max. temperature: 21 to 27 deg. F.
Average ridgetop wind direction: NE
Average ridgetop wind speed: 49 mph
Maximum ridgetop wind gust: 86 mph
New snowfall: 0 inches
Total snow depth: 31 to 37 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. Snow levels below 7000 feet. Chance of precipitation is 0%. Partly cloudy. Snow levels below 7000 feet. Chance of precipitation is 5%. Partly cloudy. Snow levels below 7000 feet. Chance of precipitation is 5%.
Temperatures: 37 to 42 deg. F. 22 to 28 deg. F. 41 to 46 deg. F.
Mid Slope Winds: Light winds. Gusts up to 25 mph in the morning. Light winds becoming west 10 to 15 mph with gusts to 30 mph after midnight. West 10 to 15 mph with gusts to 35 mph in the morning becoming light.
Expected snowfall: No accumulation. | SWE = none. No accumulation. | SWE = none. No accumulation. | SWE = none.
For 8000 ft. to 9000 ft.
Saturday Saturday Night Sunday
Weather: Sunny. Snow levels below 7000 feet. Chance of precipitation is 0%. Partly cloudy. Snow levels below 7000 feet. Chance of precipitation is 5%. Partly cloudy. Snow levels below 7000 feet. Chance of precipitation is 5%.
Temperatures: 35 to 40 deg. F. 21 to 26 deg. F. 35 to 40 deg. F.
Ridge Top Winds: Northeast 15 to 30 mph with gusts to 60 mph. Northwest 15 to 25 mph with gusts to 50 mph. Northwest 20 to 30 mph with gusts to 60 mph.
Expected snowfall: No accumulation. | SWE = none. No accumulation. | SWE = none. No accumulation. | SWE = none.
Disclaimer

This avalanche forecast is provided through a partnership between the Tahoe National Forest and the Sierra Avalanche Center. This forecast 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 forecast applies only to backcountry areas outside established ski area boundaries. This forecast describes general avalanche conditions and local variations always occur. This forecast expires 24 hours after the posted time unless otherwise noted. The information in this forecast is provided by the USDA Forest Service who is solely responsible for its content.

For a recorded version of the avalanche forecast call (530) 587-3558 x258