Wind slab on Red Lake Peak

Location Name: 
Red Lake Peak
Region: 
Carson Pass Area
Date and time of observation: 
Mon, 12/03/2012 - 13:00
Location Map: 
United States
38° 43' 14.16" N, 119° 58' 30" 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: Supportable wind slab well below ridgetops. Supportable conditions on N/NE aspects all the way down to Crater Lake, and on hwy 88 side of Red Lake Peak all the way down to exit meadow.

Pic 2: Most steep and/or corniced start zones in Crater Lake drainage had partially buried crowns (may have to click on full size image to see this) indicating a natural avalanche cycle early in the recent storms.

Pic 3: Most avalanche paths both on Crater Lake side and hwy 88 side of Red Lake Peak had buried debris indicating earlier full-path-length natural cycle.

Pic 4: Widespread settlement cracks/cones at trees.

Pit: Dug at provided lat/long on one of the few steep slopes that was not involved in previous natural cycle. Although wind slab was reactive to ECTs, it was not deep enough to be of concern, and ski cuts and several ski tracks in Crater Lake drainage failed to produce even localized failures. Surface rain crust previous to recent storm cycle at 72cm from ground, with HS of 219cm.

Video: 2nd of 2x moderate ECTPs on lower density snow just below wind slab. On 1st test wind slab fell off column cleanly, but was still SP, not SC.

Snowpit or crown profile photo or graph: 
Snowpack photos: 
Weather Observations
Blowing Snow: 
Yes
Air temperature: 
Above Freezing
Wind Speed: 
Light
Precipitation: 
None
Air temperature trend: 
Static
Wind Direction: 
Southwest
Accumulation rate: 
None
More detailed information about the weather: 

Light winds below ridgetops, moderate winds at ridgetops with light snow transport throughout day.