Observation Date
12/13/2016
Observer Name
Mark Staples
Region
Salt Lake » Big Cottonwood Canyon » Brighton Perimeter » Lacawaxan
Location Name or Route
Near Lake Lackawaxen
Red Flags
Red Flags
Recent Avalanches
Red Flags Comments
We went to the area to look at 2 recent avalanches. One was triggered on Monday by 2 snowboarders on Peak 10420. The other was on Clayton Peak and occurred on Sunday.
Snow Profile
Aspect
East
Elevation
10,200'
Slope Angle
30°
Comments

See a photo/ob from the 10420 slide HERE

See a photo/ob from the Lackawaxen slide HERE

We looked at the flank from the slide on Lackawaxen. It broke on a thin layer of facets just under an ice crust at 47 cm above the ground, about the middle of the snowpack. What surprised me is how wide and how far downhill this slide fractured. The bottom edge of the slab that released was almost at the toe of the slope. The width of the slide was at least 200ft wide. The slide on Pk 10420 was triggered by two snowboarders mid slope. Both of these features of these two slides are characteristics of faceted layers.

Today, there seemed to be less sensitivity in the snowpack. Based on other snowpits and small test slopes, triggering a slide has gotten harder to do. Spatial variability tends to increase through time until there is some unifying event like a big storm. The odds of triggering a persistent slab avalanche have gone down, unfortunately I don't know exactly how far down they've dropped. This and the spatial variability make for tricky conditions.

Video

Lastly, I dug on a south facing slope at 9200 feet and the snowpack was strong and stable and surprisingly deep.

Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate
Coordinates