THIS AVALANCHE ADVISORY EXPIRED ON February 20, 2014 @ 6:52 am
Avalanche Advisory published on February 19, 2014 @ 6:52 am
Issued by Brandon Schwartz - Tahoe National Forest

Avalanche danger is LOW for all elevations and aspects. Isolated areas of lingering unstable wind slab may remain 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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  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
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    Very Large
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Isolated areas of lingering unstable wind slab may remain above treeline on N-NE aspects in complex or extreme terrain including unsupported slopes above cliff bands. Existing wind slabs up to 1 to 2 feet thick have been observed above treeline in areas of previous wind loading. Variable rates of stabilization have occurred over the past two days. Human triggered avalanches are unlikely but not impossible at this time. Exercise normal caution and accepted best practice backcountry travel techniques in order to minimize risk.

recent observations

Observations made yesterday on Mt. Judah (Donner Summit area) and on Maggies Peak (Desolation Wilderness area) gave indications of stable snowpack conditions. Areas of lingering wind slab were shallower, smaller, and more stable than what was observed over the past few days in the Carson Pass area. Melt-freeze conditions were widespread on all aspects below 7,800'. At 8,100 to 8,200', previous deeper wet layers were in variable states of refreeze ranging from high density ice to unfrozen wet layers. Any relative weak layers in the snowpack were unreactive in snowpit tests.

Weather and CURRENT CONDITIONS
weather summary

A cold front passing through the region this morning is creating strong west winds. Ridgetop gusts have recorded at 66 mph this morning. Winds are forecast to decrease to moderate speed and shift to the northwest through the afternoon hours post frontal passage. New snow amounts of less than 1 inch fell above 6,500' to 7,000' last night over the northern third of the forecast area. To the south, no measurable amounts of precipitation were observed. Areas of lingering cloud cover are expected to clear as the day progresses. A weather system passing to the north of the forecast area tomorrow will cause increasing high level cloud cover over the region.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 25 to 30 deg. F.
Max. temperature in the last 24 hours: 37 to 45 deg. F.
Average wind direction during the last 24 hours: West
Average wind speed during the last 24 hours: 31 mph
Maximum wind gust in the last 24 hours: 66 mph
New snowfall in the last 24 hours: 0 to 1 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.
Wednesday Wednesday Night Thursday
Weather: Mostly cloudy skies with isolated snow showers early this morning, becoming partly cloudy. Partly cloudy skies. High level cloud cover. Partly cloudy skies becoming mostly cloudy.
Temperatures: 34 to 41 deg. F. 22 to 27 deg. F. 38 to 45 deg. F.
Wind Direction: West shifting to northwest in the afternoon. North West
Wind Speed: 25 to 35 mph with gusts to 55 mph, decreasing to 10 to 20 mph with gusts to 30 mph in the afternoon. Light winds Light winds increasing to 10 to 15 mph with gusts to 25 mph in the afternoon.
Expected snowfall: 0 to trace in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Wednesday Wednesday Night Thursday
Weather: Mostly cloudy skies with isolated snow showers early this morning, becoming partly cloudy. Partly cloudy skies. High level cloud cover. Partly cloudy skies becoming mostly cloudy.
Temperatures: 28 to 34 deg. F. 15 to 22 deg. F. 31 to 41 deg. F.
Wind Direction: West shifting to northwest North West to northwest
Wind Speed: 40 to 60 mph with gusts 60 to 80 mph, decreasing to 25 to 45 mph with gusts 50 to 70 mph in the afternoon. 20 to 30 mph with gusts to 50 mph. 15 to 25 mph with gusts to 35 mph.
Expected snowfall: 0 to trace 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.