Obs-Snow Profile: upper Days 2/6/2011

Observer Name:

Quino Gonzalez

Region:

Salt Lake
Big Cottonwood Canyon
Days Fork
upper Days

Observation Date:

02/06/2011

Location or Route:

Upper Days Cirque, Days Fork, BCC

Weather

Sky:

Broken

Precipitation:

Light Snowfall

Wind Direction:

Northwest

Wind Speed:

Light

Weather Comments:

Ta was -9.1 C at 9900, 1145 local time. Precip. was S-1 and wind was light (stronger on the ridge).

Snow Characteristics

New Snow Depth:

New Snow Density:

High

Snow Surface Conditions:

Dense Loose

Snow Characteristic Comments:

Surface was a dense, moist 6-7 cm. layer, 4F, very small grains, on top of a harder (1F) layer of mostly 0.3 mm grains. There was some graupel near the surface. This layer seemed quite compact and collapsed fast with a CT, so it ocurred to me that there was some potential for a soft slab release, even if we didnt see one. We saw much SH some 200 ft lower in the bowl, with crystals up to 3 mm.

Red Flags

Wind Loading

Red Flag Comments:

Maybe the wind loading with a moderate rating. The crystals are very small and there is good cohesion within the 10-15 cms of new snow on the surface. A soft release doesn't seem terribly improbable, if it gets warmer.

Primary Concern

Primary Concern:

Persistent Slabs

Probability:

Moderate

Aspect:

North

Northeast

East

Northwest

Elevation:

High

Mid

Trend:

Same

Primary Concern Comments:

The SH buried under the MLK rain crust is still reacting but with less speed and more stress in this location. However, the tests always showed a shear quality score of Q1 (and of Q2 in other pits with a slightly different aspect). We obtained CTH, ECTP (30), STH and PST 67 cm and 80 cm on 100 cm., with a clear, mostly planar shear. The MLK crust is 15 cms. thick on average here, and very strong. It didn't fail below or above in these tests. There is also a 2 cm thick ice crust 100 cms under the surface, but didnt react.

Elevation:

9900'

Aspect:

East

Slope Angle:

snow_profile_location:

Observed Danger Rating:

Moderate

Forecast Danger Rating:

Moderate