THIS AVALANCHE ADVISORY EXPIRED ON March 17, 2014 @ 6:47 am
Avalanche Advisory published on March 16, 2014 @ 6:47 am
Issued by Brandon Schwartz - Tahoe National Forest

In response to daytime warming, MODERATE avalanche danger will form today on E-SE-S-SW-W aspects on slopes 35 degrees and steeper. Human triggered loose wet avalanches will become possible. 

2. Moderate

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Above Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

2. Moderate

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Near Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

2. Moderate

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Below Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
    Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
Avalanche Problem 1: Loose Wet
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    Very Likely
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Prior to sunrise this morning, air temperatures at the mid and upper elevations are well above freezing and some 10 to 12 degrees warmer than 24 hours ago. The snow surface refreeze that occurred last night will have been driven entirely by radiational cooling under clear skies. Following sunrise, air temperatures will warm quickly this morning. The window of supportable wet snow conditions is not expected to last nearly as long today as it did yesterday. This is due to a comparatively weaker overnight refreeze and air temperatures at the mid and upper elevations reaching the upper 40s to upper 50s more rapidly today. Human triggered loose wet avalanches will become possible as the day progresses on E-SE-S-SW-W aspects.

recent observations

Observations made yesterday on Tamarack Peak (Mount Rose Backcountry) revealed that areas of wet snow became widespread on E-SE-S-SW-W aspects all the way to the summit at 9,900' in response to daytime warming. Snow conditions remained supportable well into the afternoon hours due to the presence of either several inches of melt-freeze crust or higher density wet snow remaining below the 2 to 3 inches of soft wet snow on the surface. All observed evidence of wet snow instability remained limited to human triggered minor and inconsequential roller balls.

Snow surface conditions on NW-N-NE aspects in this area were a transitional mix of pockets of shallow unconsolidated snow unaffected by melt-freeze, pockets of wind compacted snow, and pockets of frozen melt-freeze crust.

Weather and CURRENT CONDITIONS
weather summary

Strong high pressure is in place over the forecast area. Air temperature inversion has kept overnight low air temperatures between 7,000' and 9,600' in the upper 30s to mid 40s. This is 10 to 12 degrees warmer than 24 hours ago. Maximum daytime air temperatures above 7,000' are forecast to reach the mid 40s to upper 50s by this afternoon under sunny skies. In response to a weather system passing to the north of the forecast area, ridgetop winds have shifted from east to southwest and are light to moderate in speed this morning. Moderate to strong ridgetop winds are expected this afternoon, further increasing to gale force tonight. A cold front passing through to region tonight will lower air temperatures above 7,000' to near to below freezing tonight and decreasing maximum daytime air temperatures for tomorrow by 14 to 18 degrees.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 40 to 46 deg. F.
Max. temperature in the last 24 hours: 48 to 56 deg. F.
Average wind direction during the last 24 hours: East
Average wind speed during the last 24 hours: 9 mph
Maximum wind gust in the last 24 hours: 22 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 43 to 53 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Sunday Sunday Night Monday
Weather: Sunny skies. Clear skies. Sunny skies.
Temperatures: 51 to 58 deg. F. 26 to 34 deg. F. 35 to 45 deg. F.
Wind Direction: Southwest Southwest Southwest
Wind Speed: Light winds increasing to 10 to 20 mph with gusts to 30 mph in the afternoon. 15 to 25 mph with gusts to 40 mph, increasing to 25 to 40 mph with gusts to 60 mph after midnight. 25 to 40 mph with gusts to 60 mph, decreasing to 15 to 20 mph with gusts to 30 mph in the afternoon.
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Sunday Sunday Night Monday
Weather: Sunny skies. Clear skies. Sunny skies.
Temperatures: 46 to 56 deg. F. 24 to 31 deg. F. 28 to 38 deg. F.
Wind Direction: Southwest Southwest Southwest
Wind Speed: 10 to 15 mph with gusts to 25 mph, increasing to 30 to 45 mph with gusts to 55 mph in the afternoon. 50 to 70 mph with gusts to 100 mph. 50 to 70 mph with gusts to 100 mph, decreasing to 20 to 30 mph with gusts to 40 mph 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.