Sampling of Windward Conditions

Location Name: 
Frog Lake Ridge
Region: 
Carson Pass Area
Date and time of observation: 
Mon, 02/07/2011 - 11:30
Location Map: 
United States
38° 40' 53.724" N, 119° 59' 0.168" W
See map: Google Maps
US


Red Flags: 
Observation made by: Professional Observer
Snowpit Observations
More detailed information about the snowpack: 

Frog Lake Ridge provided a good sampling of the variety of windward surface conditions.

pic 1: Thin melt/freeze layer observed in both melt and freeze states at and below treeline on ~W aspects. On below treeline aspects well shaded by trees, ~15cm of unconsolidated DFs remain on surface.

pic 2: Breakable wind crust at and above treeline.

pic 3: Soft sastrugi at and above treeline. Mature, hard sastrugi and hard wind slab were also observed above treeline on windward aspects (lee aspects throughout previous week).

The one common theme among all these surface conditions was that the Light below treeline and Moderate above treeline SW winds failed to produce much wind transport. The least consolidated surface snow was also receiving the least wind, and vice versa.

pic 4: Lee aspect of Elephant's Back was Knife hard crust scoured by previous week's E winds. The very few grains observed being transported by SW winds weren't bonding, but were settling in depressions.

Snowpack photos: 
Weather Observations
Blowing Snow: 
No
Air temperature: 
Above Freezing
Wind Speed: 
Moderate
Precipitation: 
None
Air temperature trend: 
Static
Wind Direction: 
Southwest
Accumulation rate: 
None
More detailed information about the weather: 

SW winds appeared to be increasing, but never beyond Moderate above treeline through mid-day.