Natural Avalanche on Round Top

Location Name: 
Cresent Coular
Region: 
Carson Pass Area
Date and time of avalanche (best estimate if unknown): 
Tue, 02/22/2011 - 00:00
Location Map: 
United States
38° 39' 53.5356" N, 119° 59' 37.9572" W
See map: Google Maps
US


Red Flags: 
Recent avalanche activity
Recent loading by new snow, wind, or rain
Obvious avalanche path
Observation made by: Public
Avalanche Observations
Avalanche Type: 
dry,slab,
Slope: 
40degrees
Trigger type: 
Natural
Crown Height: 
3 ft
Aspect: 
Northeast
Weak Layer: 
Storm Snow
Avalanche Width: 
400ft.
Terrain: 
Above Treeline
Elevation: 
9 300ft.
Bed Surface: 
Storm Snow
Avalanche Length: 
800ft.
Number of similar avalanches: 
2
More detailed information about the avalanche: 

 On a tour along the Carson Range we noticed seriously high ridgetop winds blowing inches of snow N-NE-E.  Once we dropped into Winnemuca Lake we observed a fairly large debris pile, including a few refridgerator size blocks, sitting on top of the majority of the debris, covered in wind load.  A hundred yards lookers right from that we noticed another slide which again traveled to the lake.  Our obsevations of particularly strong NE wind Loading, would be our estimate for the cause of failure, as the high rate of windloading could be seen all day long.  We assume the slide happened over night in response to the continuous windloading.  We also noticed sizeable cornice blocks sitting midslope on the Lookers Right slopes on the E face of Elephants Back.  The cornice failure did not cause any further complications.

Avalanche Photos: 
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
25% of the sky covered by clouds
Air temperature: 
Wind Speed: 
Strong
Precipitation: 
None
Air temperature trend: 
Wind Direction: 
Northeast
Accumulation rate: 
More detailed information about the weather: 

 Cloud Cover began to appear over the area yesterday with increasing winds, as the forcasted storm entered the area.  Observed clouds in the increasing cover were cumulonimbus, wind born snow, and lenticular clouds.  Looks like this storm is shapping up to be a doozie.