Observations from Carson Pass

Location Name: 
Frog Lake Ridge
Region: 
Carson Pass Area
Date and time of observation: 
Tue, 03/13/2012 - 16:00
Location Map: 
United States
38° 41' 23.8128" N, 119° 59' 12.5736" W
See map: Google Maps
US


Red Flags: 
Recent loading by new snow, wind, or rain
Observation made by: Professional Observer
Snowpit Observations
More detailed information about the snowpack: 

Minimal new snowfall coupled with significant winds led to new snow distribution almost entirely isolated to windloaded terrain features.

Within the new snowfall (20 to 40cm on windloaded features), 2 layers of concern were observed:

  • A lighter density layer just beneath the surface that did not present a hazard today, but may once loaded by more snow
  • A lighter density layer at the base of the new snow, that is comprised of graupel and rimed precip. This layer failed easily on several hand shears throughout the area, but did not show propogation potential on ECTs. Not enough slab developed on top of it yet. Ski cuts on test slopes produced loose dry results on this layer.

Just under the new snow lies either old DFs on top of a MFcr, or just the MFcr. Where the new snow lies on top of just the MFcr, facets are beginning to develop under the MFcr and are clearly angular to the naked eye. Where the new snow lies on top of DFs and the MFcr, the facets did not appear to be as angular, but still resulted in easy, planar hand shears.

ECT results were mixed on this newest faceted layer, with 2x ECTP and 3xECTN in various locations. I believe the slab was not well enough developed yet for consistent results.

PST results were much more consistent, with 5x PST (END) results at 30/100 or less - again in various windloaded locations. All PSTs were performed just under the MFcr nearest the surface.

Video: results consistent with other PSTs. Note the layering in the storm slab as I remove it after propogation.

 

Weather Observations
Blowing Snow: 
Yes
Air temperature: 
Below Freezing
Wind Speed: 
Strong
Precipitation: 
Snow
Air temperature trend: 
Static
Wind Direction: 
West
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: 

Strong winds with Extreme gusts - within a mile of the road, 2 full-sized live trees were recently blown down.