Faceted Snow and Whumpfing on Carson Pass

Location Name: 
Woods Lake
Region: 
Carson Pass Area
Date and time of observation: 
Fri, 12/29/2017 - 12:30
Location Map: 
United States
38° 40' 53.3568" N, 120° 1' 9.3432" W
See map: Google Maps
US


Red Flags: 
Whumphing noises, shooting cracks, or collapsing
Observation made by: Forecaster
Snowpit Observations
More detailed information about the snowpack: 

Variable snow surface conditions exist throughout this area.  On NW-N-NE aspects, weak faceted snow exists below the snow surface in many wind protected areas.  In near and above treeline terrain, many areas are wind scoured with areas of hard wind slabs.  In below treeline terrain, soft slabs exist in isolated areas above the weaker faceted snow.  A high degree of variability exists throughout the different elevation bands, with differing facet layer and slab thickness combinations.  We could not intentionally trigger any avalanches on small test slopes but we did observe whumpfing and collapsing in 3 different areas.  Snowpack tests also all showed results that the faceted layer is weak and that propagation is possible if initiated.  

Snowpit or crown profile photo or graph: 
Snowpack photos: 
Weather Observations
Blowing Snow: 
No
Cloud Cover: 
50% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Light
Precipitation: 
None
Air temperature trend: 
Warming
Wind Direction: 
Southwest
Accumulation rate: 
More detailed information about the weather: