Small Wind Slabs on Tamarack

Location Name: 
Tamarack Peak
Mount Rose Area
Date and time of observation: 
Tue, 01/09/2018 - 11:30
Location Map: 
United States
39° 19' 17.8176" N, 119° 55' 36.4044" W

Red Flags: 
Recent avalanche activity
Recent loading by new snow, wind, or rain
Obvious avalanche path

Observation made by: Forecaster
Snowpit Observations
More detailed information about the snowpack: 

5 to 8 cm (2 to 3 inches) of new snow had fallen in the Tamarack Peak area since yesterday. Below 9300 ft. the new snow rested on top of wet snow and a small rain crust. The new snow was wet and sticky in some areas at these lower elevations and fast and supportable in other areas. Above 9300 ft. the new snow was drier and colder. We dug test pits on N and NE aspects at 9500 ft and 9800 ft. on Tamarack Peak and at 10200 ft. on Mt. Houghton looking for signs of instability related to facet layers. We probed and dug hand pits on several other N-NE aspects between 9500 ft. and 10200 ft. on Tamarack Peak and Mt. Houghton. In all but one of those areas we did not find any signs of instabilities related to the old facet layer. At our test pits we got ECTN results and PST's with cut lengths longer than 50% of the column. The facet layer was not well developed and it was consistently 1F in hardness. One shallow spot near the ridge at 10200 ft. on Mt Houghton did have well developed facets around some rocks, but we could not find a spot where these were continuous enough to do a snowpack test. 

Ski cuts on wind loaded test slopes did trigger some cracking and one ski cut on a small wind-loaded slope near the ridge on Tamarack Peak released a small wind slab. This slab was about 15 to 20 cm (6 to 8 inches) deep and about 2m (6 ft.) wide and extended downslope ~1-1.5m (3 to 4 ft). This test slope was a steep wind-loaded rolloverr. 

Warm temperatures and wet surface snow also allowed some small loose wet instabilities like roller balls and pinwheels especially in areas below 9500 ft. 

Photo 1: Small wind slab failure resulting from a ski cut on a small wind-loaded test slope near the ridge at 9700 ft. on a NE aspect.

Photo 2: ECTN on a N aspect at 10200 ft. on My Houghton. This test was representative of the other snowpit tests we performed today. 

Snowpack photos: 
Weather Observations
Blowing Snow: 
Cloud Cover: 
75% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Air temperature trend: 
Wind Direction: 
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: 

Air temperatures hovered close to freezing even at the highest elevations during our tour. 

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