Observation: 10420

Observation Date
3/20/2017
Observer Name
Evelyn
Region
Salt Lake » Big Cottonwood Canyon » 10420
Location Name or Route
10,420'
Weather
Sky
Broken
Wind Direction
South
Wind Speed
Light
Weather Comments
Mostly cloudy, including spring like cumulus. When there were a few breaks...the full sun was intense. Winds were mostly calm, with occassional light gusts. Very warm. 46 °F at the Guardsman trailhead at 9 am.
Snow Characteristics
Snow Surface Conditions
Damp
Snow Characteristics Comments

Seemed to be no overnight refreeze on any of the aspects and elevations I traveled (8,900' to 10,420"). Snow was supportable however, and very good corn skiing on NW, N, NE and E facing slopes - anywhere you could find smooth surfaces. Southerly facing slopes were a bit punchy from the start, even at 9 am.

Red Flags
Red Flags
Rapid Warming
Poor Snowpack Structure
Red Flags Comments
More like continued warming than rapid warming. Temperatures on near by Jupiter Peak have only dropped to freezing for a few hours in the past week. I think wet snow, glide and cornice avalanche danger will be with us for several more days. Another warm night, a warm day tomorrow. Then even when temperatures finally cool and/or it snows, the old snow beneath the crusts and insulating new snow will stay wet and weak for several days.
Comments

Dug a pit on northwest facing slope, at 10,125'. I was expecting up to a foot of damp to wet snow, and maybe the dust layer beneath, then dry snow...nope. Way more interesting. Reminds me why I need to get out my shovel and dig or I won' t really know what's beneath my feet. There was a bit of variation in the layers just across the short distance of the snow pit wall, which to me means you may need to dig in a few spots to find the weakest and most concerning snow. I'm also wondering if there can be more spacial variation in wet snow than dry.

I dug down from the surface to just below the frozen third crust, where the snow become drier and was pencil hardness. The snow was moist from the surface all the way down to this third crust/layer, with two wet layers.

The upper wet layer was the weakest, "Very Wet" with free water, and it's a bit spooky to know that's what's beneath the supportable "corn". After seeing this, we avoided skiing the steepest slopes and roll overs on the way down.

Lower photo is a close up of the weak upper wet layer, dug out a bit.

The snow on the south to southwest facing slopes is really taking a hit along the ridge lines. The snow pack in that terrain is generally shallow to start with due to wind erosion, and now the warm temperatures and sun have melted it down to dirt.

Lower photo is looking over at Claytons - you can see where the snow sluffed earlier, down to the thin dust layer.

As always, a cornice shot or two. The upper cornice was at about 9,500', and water was dripping steadily off the upper face in several places.

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