Observations from S Carson Range

Location Name: 
Porcupine Ridge
Region: 
Luther Pass Area (including Job and Freel)
Date and time of observation: 
Thu, 03/17/2011 - 12:00
Location Map: 
United States
38° 55' 0.12" N, 119° 53' 11.4" W
See map: Google Maps
US


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

Pic 1: Wind slab was fragile along ridge tops, but decreased in depth very quickly away from ridge.

Pic 2: In the most heavily wind loaded areas, where slab thickness was greatest, slab needed to first be undercut to break. Note this didn't run any distance even though terrain remained steep.

Pic 3: Consistent light to moderate wind transport. Winds kept snow surface cool, and grains available for transport.

Less than 10m downslope from ridgetops, ECTs and PSTs showed a lack of propagation potential just below new wind slab. Although certain terrain features allowed wind loading farther downslope, no signs of propagation potential were observed below ridgetops.

Most snow within 50cm of surface showed riming, with very small graupel mixed with rimed DFs just below wind slab.

A thin layer of 4F rimed DFs remain beneath crust layer from previous wet event. This layer was reactive to RBs performed in the area on 3/16, but did not present a concern today.

Snowpack photos: 
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
Clear
Air temperature: 
Below Freezing
Wind Speed: 
Moderate
Precipitation: 
None
Air temperature trend: 
Static
Wind Direction: 
South
Accumulation rate: 
None
More detailed information about the weather: 

Winds shifted from SE in the morning to S/SW in the afternoon, and increased from light to moderate.