Small avalanche in the Hourglass

Location Name: 
Tamarack Peak
Region: 
Mount Rose Area
Date and time of avalanche (best estimate if unknown): 
Sat, 02/19/2011 - 11:35
Location Map: 
United States
39° 19' 7.5396" N, 119° 55' 18.2532" W
See map: Google Maps
US


Red Flags: 
Recent loading by new snow, wind, or rain
Obvious avalanche path
Observation made by: Forecaster
Avalanche Observations
Avalanche Type: 
dry,slab,
Slope: 
36degrees
Trigger type: 
Other - explain below
Crown Height: 
1 ft
Aspect: 
North
Weak Layer: 
Storm Snow
Avalanche Width: 
50ft.
Terrain: 
Near Treeline
Elevation: 
9 840ft.
Bed Surface: 
Storm Snow
Avalanche Length: 
25ft.
More detailed information about the avalanche: 

Photos 1 through 3: Small hard slab avalanche in Hourglass Bowl intentionally triggered by kicking a small cornice section onto the slope below.

Photo 4: Wind transport refilling the skin track over the summit of Tamarack Peak after 20 minutes.

The slab involved in this avalanche was easily identifiable top to bottom on the peak on N-NE-E aspects. A testpit dug just to the SE of the summit on wind loaded test slopes with similar aspect and elevation to Hourglass Bowl yielded ECTN results on a wind slab of very similar characteristics (30cm deep 1F hard slab over 4F storm snow). Slab is likely a mix of wind effect and higher density snow that fell last night.

Avalanche Photos: 
Weather Observations
Blowing Snow: 
Yes
Air temperature: 
Below Freezing
Wind Speed: 
Moderate
Precipitation: 
None
Air temperature trend: 
Warming
Wind Direction: 
Southwest
Accumulation rate: 
More detailed information about the weather: