Professional Observation

Observation Details

Signs of Unstable Snow

Snow Stability

Key Points

Toured up to Sherwin ridge today from Mill city to see if I could find any soft snow in the sheltered north-facing trees near Mammoth rock.

• No signs of instability were observed on my tour today. I did note some breakable wind board resting on near-surface facets. The wind board measured 1-5″ deep that sheeted off in large chunks 1-4+’ in diameter. Nothing voluminous enough to be considered a stability concern. However, encountering this type of snow in a steep and committing location could be disconcerting and could be a fall hazard.
• Significant snow settlement has occurred over the past couple of weeks as evidenced by large cracks around trees and settlement cones upwards of 4′.
• Lots of Tree debris, gravel, and wind textures litter the slopes.
• I dug in at about 9800 ft On a NE Aspect. The total height of snow in this location was 255cm and I found the upper part of the snowpack to be mostly right side up and stable. See pit profile for more details
• Surface conditions would be best described as variable and proved to be the largest hazard of the day. I found substantial wind boards ranging from 1-3″ breakable to close to 10″ thick, fully supportable, and quite slick. Ski crampons were very useful for my ascent from Mammoth rock. I also found several areas of soft faceted surface snow that made for pleasant turns in the most sheltered and tightly treed areas.  Unfortunately, surface conditions often changed from one turn to the next.