THIS AVALANCHE ADVISORY EXPIRED ON February 3, 2016 @ 6:55 am
Avalanche Advisory published on February 2, 2016 @ 6:55 am
Issued by Steve Reynaud - Tahoe National Forest

Moderate avalanche danger exists on all aspects near treeline and above treeline due to existing wind slabs and new wind slab development due to shifting winds.  Low avalanche danger exists on all aspects below treeline.  Evaluate snow and terrain carefully, identify features of concern.

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.

1. Low

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Below Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
    Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
Avalanche Problem 1: Wind Slab
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    Certain
    Very Likely
    Likely
    Possible
    Unlikely
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    Historic
    Very Large
    Large
    Small

Winds slabs will remain possible today on SE-S-SW-W aspects near treeline and above treeline from yesterdays NE wind event.  Wind have shifted to the SW-W last night and are in the moderate to strong range.  Newly formed wind slabs will be possible on NW-N-NE-E-SE aspects near treeline and above treeline.  In near and above treeline terrain a mix of scoured snow surfaces and wind slabs will likely coexist on all aspects.  Look for wind scouring, cornice formation, wind pillows and snow surface clues to help identify suspect slopes. 

Areas of exposed rain crust on the snow surface are likely on windward aspects above treeline. The potential exists for long sliding falls with very difficult self arrest conditions.

recent observations

2 separate human triggered wind slab avalanches were reported from the Mt. Rose area yesterday.  On the East Ridge of Relay Peak, 9500', E/NE aspect, a dense wind slab with a crown line up to 12'' deep was skier triggered in an open area near treeline.  This avalanche was reported to be 100' wide and ran 150' downslope.  West of Incline Lake Peak on a S/SE aspect, 37 degree slope, a wind slab was boarder triggeredAvalanche was 35' wide and ran 125' downslope with an 8'' crown.

Other observations from Tamarack Peak (Mt. Rose area) and Carpenter Peak (Independence Lake area) also showed large amounts of wind transport.  Stiff wind slabs were observed on SE-S-SW-W aspects near and above treeline from the NE wind event.  These areas hold up to 1-2' of available snow for transport as the winds change direction.  Exposed terrain to the NE winds were typically scoured down to the previous rain crust, dense wind effect, or breakable crust.  Protected areas below treeline provided unconsolidated snow with good travel conditions.



 

Weather and CURRENT CONDITIONS
weather summary

Increasing clouds throughout the day with a slight chance of snow showers and flurries possible by late morning into early afternoon.  Little to no accumulation expected with below average temperatures.  Highs in the teens to low 20's with West winds 20 to 30mph and gusts to 40mph above 8000'.  Another small disturbance is expected to push through our area Wednesday night which may have a better chance of bringing light accumulations.  A quiet weather pattern will develop with drier conditions and warming temperatures into the weekend.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 9 to 11 deg. F.
Max. temperature in the last 24 hours: 24 deg. F.
Average wind direction during the last 24 hours: SW
Average wind speed during the last 24 hours: 20 to 30 mph
Maximum wind gust in the last 24 hours: 61 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 72 to 85 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Tuesday Tuesday Night Wednesday
Weather: Mostly cloudy. Chance of snow showers. Mostly cloudy. Mostly cloudy. Chance of snow in the afternoon.
Temperatures: 20 to 27 deg. F. 6 to 16 deg. F. 27 to 34 deg. F.
Wind Direction: W NW SW
Wind Speed: 10 to 15mph with gusts to 25mph in the morning. NW 10 to 15 mph shifting to the SE after midnight. Light winds becoming SW 20 to 25mph with gusts to 35mph.
Expected snowfall: Trace in. 0 in. 1 in.
For 8000 ft. to 9000 ft.
Tuesday Tuesday Night Wednesday
Weather: Mostly cloudy. Chance of snow showers. Mostly cloudy. Mostly cloudy. Chance of snow showers in the afternoon.
Temperatures: 16 to 23 deg. F. 4 to 11 deg. F. 24 to 31 deg. F.
Wind Direction: W SW W
Wind Speed: 20 to 30mph with gusts to 40mph. 15 to 20mph with gusts to 35mph. 20 to 25mph with gusts to 35mph increasing to 35 to 40mph with gusts to 60mph in the afternoon.
Expected snowfall: Trace in. 0 in. 1 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.