Snowpack Observations Mt. Rose

Location Name: 
East Ridge Tamarack Peak
Region: 
Mount Rose Area
Date and time of observation: 
Tue, 02/28/2012 - 13:00
Location Map: 
United States
39° 18' 50.4468" N, 119° 54' 48.96" W
See map: Google Maps
US


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

2 main instabilities existed within the new storm snow today.  The first was 5cm above the old snow/new snow interface on a rimed crystal layer, the 2nd was on the newly forming wind slab.  There was a good bond between the old snow/new snow interface.  In wind loaded areas this forming wind slab was well over 1' by afternoon.  These layers were reactive today with natural avalanche activity and easy human triggered activity on NE-NW aspects in heavily wind loaded terrain.  These layers were found with CT's on NE-NW aspects between 9100-9400' with easy to moderate shears in wind loaded terrain.  On East aspects of Prolitariate Bowl there were small sluffs in the steeper terrain from ski turns.

CT's also revealed sudden collape failure on a facted layer just below the 2 crust combo within the old snow surface.  The 2 crust combo consists of a melt freeze crust and the late January rain crust that had faceted grains above, in between and below the crusts.  Failures were consistent below the 2 crust combo with the CTM, 4 ECTP in the Moderate range, and PST 25/100 END down 45cm on facets below the 2 crusts-9400' NE aspect, 30 degrees.  Additional PST on video.

No avalanche activity was related to the persistent buried faceted layer that we observed today.  This layer did show very consistent results with all of the stability tests.   

Photo:  Shooting cracks and small wind slab release on convex rollover.  9400', N aspect, 35 degree slope in wind loaded terrain.

Video:  PST 27/100 END down 60cm on faceted grains below the 2 crust combo.  9100', N aspect 32 degree slope. 

Snowpack photos: 
Snowpit videos (tests, etc): 

mtrose2012-2-28 007.avi

Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
50% 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: 

Some brief clearing in the morning hours before the clouds came back in.  Moderate SW winds moving snow on exposed areas, winds increasing into the afternoon.  Light snow started around 3pm.