Shooting cracks and snowpit observations from near Frog Lake

Location Name: 
Frog Lake
Region: 
Carson Pass Area
Date and time of observation: 
Tue, 03/02/2010 - 14:00
Location Map: 
United States
38° 41' 24.4788" N, 119° 59' 1.3416" W
US


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

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

Winds transporting snow onto the N-NE-E aspects all day near ridglines in this area. 1-2 inches of new snow had accumulated above 8000' by 3pm near Carson Pass today. This new snow and wind transport had started to from small soft wind slabs on the N-NE-E aspects near and above treeline by 1pm. Some small skier triggered cracks occurred on N-NE facing, 35-38 degree, wind-loaded test slopes at 8900' by 2pm. The soft slabs on these test slopes ranged from 2-6 inches thick (see photo # 1). Snowpits on a NE facing wind loaded slope near treeline (pit #1) and a N facing non-wind-loaded slope below treeline (pit #2 and photos #2 and #3) both showed a thin crust with some small weak sugary snow grains below it at the Feb. 19th interface. In both of these pits this interface had gained enough strength to support the current snowpack. Propagation tests also indicated that fracture propagation along this interface is less likely now than on previous days. However, layer bonding tests on this layer indicated that it could still fail if enough force is applied. with more snow forecasted tomorrow this layer could reactivate. The upper snowpit was dug in a safe spot near a rock outcrop (a common trigger point). The upper snowpit is at on the 8800 ft contour due west of the coordinates attached to this observation and the lower pit is at the intersection of the road and the 8400' contour due north of the observation coordinates. Each pit has more specific coordinates in its header.

Snowpit or crown profile photo or graph: 
Snowpack photos: 
Any other comments about the observation or links to outside pages that have more info on the observation: 

 

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: 
Cooling
Wind Direction: 
Southwest
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: 

Snowing about .5 inches per hour starting at 1pm today.