Quick report
- Cracking
- isolated
We observed isolated pockets of instability, with shooting cracks (6-15') observed when traversing above a skin track. Observed instability was primarily confined to the wind-loaded and warmer slopes on the SW aspect of Big Bowl. These regions had significantly more wind-transported snow and were fracturing ~6-8" below the snow surface on a new/old snow interface.
Weather
- Cloud Cover
- clear
- Wind Loading
- light
- Snow Avail For Transport
- small smounts
Significant NNW winds were observed at 11,500' and above. Within the 11,500-11,800, winds were in the 20-50 mph range throughout the day. At higher elevations, winds were increased and actively stripping windward slopes.
Snowpack
On N and NNW aspects, the November 17-20 storm snow has begun to facet and has developed a harder slab on top of it. The slab height was highly variable across space, ranging from ~6 to 18 inches of pencil-hard snow. The facets underneath this slab are not well developed, with a hardness of 4F, and remain small. I expect the faceting process to continue on the colder, sheltered, and shallow slopes, as they experience continued change with colder nights and limited sun. Test results were conducted on a 30-degree slope at 11,800 and as follows: CT15 (RP) , ECTP17, and PST50/100SF (x2). All failures occurred just below the slab due to a slight density change in the looser faceted snow ~30cm below the snow surface at this location. Overall, our findings identified a poor snowpack structure with moderate strength and propagation propensity.
The height and consistency of the slab on slopes with developed and developing facets should continue to be monitored, as this may be a significant concern with additional faceting and/or snow.