Obs from Tamarack Pk

Location Name: 
Tamarack Peak
Region: 
Mount Rose Area
Date and time of observation: 
Fri, 03/25/2011 - 14:30
Location Map: 
United States
39° 19' 0.7284" N, 119° 55' 10.0632" W
See map: Google Maps
US


Red Flags: 
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain
Observation made by: Forecaster
Snowpit Observations
More detailed information about the snowpack: 

Shooting cracks common in wind loaded and moderately wind affected areas above and below treeline. No evidence of instability in wind protected areas below treeline.

Photo 1: Test slope slab failure triggered by intentional cornice collapse at noted lat/long (9,800', NE aspect, 40 degree slope angle in near treeline terrain). Slab failed on thin weak layer of rimed crystals 10cm above a significant density change to lower density snow. Slab and bed surface were both 4F hard with no easily discernable difference. Slab thickness was 10 to 20 cm.

Photo 2: Shooting cracks along the far east ridge of Tamarack Peak, similar to skier triggered cracking observed elsewhere on the peak.

There seemed to be instability on both a layer of rimed crystals 10 to 20 cm below the snow surface as well as a slightly deeper instability on a density inversion 30 cm below the snow surface. Cracked occurred on one weak layer or the other in various locations with no real pattern to differentiate.

Significant graupel (2-3mm) observed falling from the sky and accumulating on the snow surface in this area from 1pm to 3:30pm today. Possibly a storm snow weak layer after more accumulation tonight/tomorrow.

Snowpack photos: 
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Moderate
Precipitation: 
Snow
Air temperature trend: 
Static
Wind Direction: 
Southwest
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: 

Significant ongoing blowing snow all afternoon.