New snow avalanche problems

New snow avalanche problems

Date
Activity
Snowmobiling

This afternoon we rode up to Henderson Bench, then up Lulu road to the Cabins below Scotch Bonnet. It was snowing lightly most of the day with light to moderate wind. Wind was steady moderate near Lulu Pass. Visibility was limited, but we got a brief look at some of Henderson Bench and Scotch Bonnet. 

We saw 3 avalanche that broke 6-10" deep within the recent snow, R1-D1s, 20-40' wide. 

For the next 1-2 days I expect any fresh drifts will be easy to trigger. There are some density changes within the recent snow that could cause storm slab avalanches to break easier on non-wind loaded slopes.

We dug on a northeast facing slope at 9,360' elevation. Below the dust layer that was deposited at the end of last week's storm there is a lower density layer of precipitation particles that was preserved. This produced an ECTN in our test, but seems like it could contribute to avalanches for the next few days at least. (profile attached).

Snow that fell since last weekend was settled to about 2.5-3 feet. We did find some small facets buried below the last week's snow, but they were not showing obvious signs of being a widespread problem. I am still cautious that larger, wider avalanches could break on this facet layer until the snowpack has 1-3 more days to adjust to the weight of recent snow, especially on wind-loaded slopes.

Practice cautious route finding and careful snowpack assessment as avalanches are likely within the recent snow, and possibly could break 2-4 feet deep below all the snow that fell over the last week.

Region
Cooke City
Location (from list)
Henderson Bench
Observer Name
Alex Marienthal