Obs-Snow Profile: Mineral Fork 2/9/2011

Observer Name:

Greg Gagne

Region:

Salt Lake
Big Cottonwood Canyon
Mineral Fork

Observation Date:

02/09/2011

Location or Route:

Mineral Fork

Weather

Sky:

Scattered

Weather Comments:

Sky was clear, but quickly grew more obscured and even had a few very light instability showers. Temp was -10C on a N-facing study pit at 8400'

Snow Characteristics

Snow Surface Conditions:

Powder

Faceted Loose

Snow Characteristic Comments:

Monday night storm snow has settled to 20-30 cm. In many quick pits I did notice 1 cm thick graupel layer interfacing new and old snow surface with really large (5mm - 1 cm) graupel pellets.

Primary Concern

Primary Concern:

Persistent Slabs

Probability:

Moderate

Aspect:

North

Northeast

East

Southeast

Elevation:

High

Mid

Trend:

Same

Primary Concern Comments:

Primary concern in this area was the faceted snow sitting above and below the MLK crust. In this area, the crust is only buried about 35 cm deeply at 8400' on N/NE aspect, but I suspect strong NE winds last week scoured away much of the snow surface which explains why the crust isn't buried too deeply from the surface. Aspects are really a best guess as they all have an Easterly component to them.

Elevation:

8400'

Aspect:

North

Slope Angle:

snow_profile_location:

United States

40° 37' 11.8056" N, 111° 41' 31.164" W

Comments - Photos - Videos (group 1)

I was in this area about 2 weeks ago and the layers above and below the MLK crust have weakened as they continue to facet. The crusts are also continuing to deteriorate. Have attached a pit profile which illustrates the slight temperature gradient both above and below the crust. Stability tests were of no concern (STM above the crust, CT 28 PC below the crust.) However, this is more of a function that there wasn't much of a slab on top of these buried weak layers. What is more of a concern is that this pit shows a poor structure and that the faceted layers are continuing to grow weaker. My pit at 8400' showed a 3-5mm rain crust. A quick pit on a NE-aspect at 9400' showed a 1 cm crust, with weak faceted snow quite obvious below the crust. A slab seems to be the missing ingredient. However, it is worth mentioning I did not get any collapses today.

Overall the pattern I have noticed since the rime/rain event over MLK weekend is that upper LCC seems to have a crust 5-10 cm thick and the crust seems to effectively bridge any weaknesses below the crust. In mid and upper BCC, the crust seems to be thinner and also seems to be deteriorating more quickly.

Observed Danger Rating:

Low

Forecast Danger Rating:

Low

Snow Profile Location

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