THIS AVALANCHE ADVISORY EXPIRED ON February 21, 2014 @ 6:56 am
Avalanche Advisory published on February 20, 2014 @ 6:56 am
Issued by Brandon Schwartz - Tahoe National Forest

Avalanche danger is LOW for all elevations and aspects. Isolated areas of unstable wind slab may exist above treeline on N-NE aspects in complex or extreme 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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    Certain
    Very Likely
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Isolated areas of unstable wind slab may exist above treeline on N-NE aspects in complex or extreme terrain including unsupported slopes above cliff bands. Isolated areas of blowing snow yesterday may have allowed for isolated areas of new wind slab less than 1 foot thick to form above treeline on N-NE aspects. Human triggered avalanches are unlikely but not impossible today. Exercise normal caution and accepted best practice backcountry travel techniques in order to minimize risk.

recent observations

Observations made yesterday on Tamarack Peak (Mount Rose backcountry), Rubicon Peak (West Shore Tahoe area), and on Thunder Mountain (Carson Pass area) all gave indications of good stability for the overall snowpack and wind slabs that formed last Saturday night and Sunday morning. A relative weak layer of lower density snow remains prominent just below the wind slab, but formal and informal tests indicate that propagation following a collapse of this weak layer is unlikely.

A new round of blowing snow was observed mid day yesterday on isolated above treeline peaks such as Dick's Peak in the Desolation Wilderness. This will have created some amount of new wind slab in isolated areas above treeline.

Weather and CURRENT CONDITIONS
weather summary

Yesterday morning's snow showers brought a quick trace to two inches of new snow to the forecast area. Cloud cover cleared out yesterday morning and high pressure continues to build over the forecast area. Ridgetop winds shifted from west to east yesterday evening and are moderate in speed this morning. Thin high level cloud cover will increase this afternoon as a weather system passes to the north of the forecast area. In association with the passing weather system, winds are forecast to shift to southwest this afternoon and remain moderate in speed. A gradual warming trend is expected over the next several days. Maximum daytime air temperatures today for areas above 7,000' are forecast to reach the mid 30s to mid 40s.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 26 to 30 deg. F.
Max. temperature in the last 24 hours: 34 to 42 deg. F.
Average wind direction during the last 24 hours: West shifting to east
Average wind speed during the last 24 hours: W 30 mph | E 14 mph
Maximum wind gust in the last 24 hours: W 66 mph | E 26 mph
New snowfall in the last 24 hours: trace to 2 inches
Total snow depth: 37 to 49 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Thursday Thursday Night Friday
Weather: Partly cloudy skies becoming mostly cloudy. High level cloud cover. Partly cloudy skies becoming clear. Partly cloudy skies becoming sunny.
Temperatures: 40 to 46 deg. F. 20 to 28 deg. F. 41 to 47 deg. F.
Wind Direction: Northeast shifting to west West Southwest
Wind Speed: 10 to 15 mph. 10 to 15 mph. 10 to 20 mph.
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Thursday Thursday Night Friday
Weather: Partly cloudy skies becoming mostly cloudy. High level cloud cover. Partly cloudy skies becoming clear. Partly cloudy skies becoming sunny.
Temperatures: 33 to 39 deg. F. 21 to 26 deg. F. 34 to 40 deg. F.
Wind Direction: Northeast shifting to southwest West West
Wind Speed: 15 to 20 mph with gusts to 40 mph. 15 to 25 mph with gusts to 45 mph. 15 to 20 mph with gusts to 35 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.