Obs-Snow Profile: Circle Awl 1/30/2011

Observer Name:

Quino Gonzalez

Region:

Salt Lake
Big Cottonwood Canyon
Circle Awl

Observation Date:

01/30/2011

Location or Route:

All Circle Peak/BCC

Weather

Sky:

Broken

Wind Direction:

West

Wind Speed:

Moderate

Weather Comments:

Mild temperatures and a moderate breeze, was around 2 C at 9000 ft by 1300, with a scattered to broken transition in the early afternoon.

Snow Characteristics

Snow Surface Conditions:

Melt-Freeze Crust

Snow Characteristic Comments:

Surface was a 2 cm. melt-freeze crust in most areas on West aspect of All Circle Peak. The rain crust is 22 cms. under the surface and is 10 to 13 cms. thick. Height of the snowpack here is only 125 cms. Contrary to all the tests I have done in the past 10 days or so, the weak layer here was on top of the rain crust, not under it (103 cms from the bottom and 22 cms from the surface). The ECT, CT and ST exposed the same weakness, with a shear quality of Q2. There was no propagation in the ECT. I didnt really see facets in this weak layer but only a few DF particles. Also, I didnt really find any SH under the rain crust.

Red Flags

Collapsing

Red Flag Comments:

So the melt-freeze surface crust did collapse a few times. My skis went through it and into the 20 cm. layer of mostly rounded grains that separates this surface from the rain crust. Now this was quite supportable. But, as I said, the weakness is on top of the rain crust here. So we have 22 cms. on top of the weak layer including a melt freeze crust on the surface, and supposedly a storm coming. I am not sure how all this adds up. I will have to ask Mr. Kimbrough.

Primary Concern

Primary Concern:

Persistent Slabs

Aspect:

West

Elevation:

Mid

Trend:

Same

Primary Concern Comments:

I guess it will interesting to see how this weakness on top of the big rain crust reacts under a new load, if we get a lot of snow.

Elevation:

8500'

Aspect:

West

Slope Angle:

snow_profile_location:

Observed Danger Rating:

Moderate

Forecast Danger Rating:

Moderate