Obs-Snow Profile: Skyline 12/30/2010

Observer Name:

Darce Trotter Steve Cote

Region:

Skyline

Observation Date:

12/30/2010

Location or Route:

Lower Electric Lake

Weather

Sky:

Overcast

Precipitation:

Light Snowfall

Wind Direction:

West

Wind Speed:

Moderate

Weather Comments:

Big relentless wind standard for the plateau, cold temps moving in, was -14 C at 1000, and temps continued to drop. Visibility was very poor, as expected, anywhere near summit ridges. We did have good enough vis to ski lower slopes, but deteriorated later in the day. Snowfall light and sideways, transport obvious driving over the top.

Snow Characteristics

New Snow Depth:

18"

New Snow Density:

Medium

Snow Surface Conditions:

Wind Crust

Snow Characteristic Comments:

45 cm of new at Miller Flat, total depth now 155cm, has settled significant amount. Winds have formed highly variable wind slabs, big cornices, and hard slabs, and feel very confident that a natural cycle has occurred on N through E aspects. Cold temps will slow healing of new load, suspect density inversions and MF crust approx 50 cm down as most probable failure zones, still feel very good about deeper pack.

Red Flags

Recent Avalanches

Heavy Snowfall

Wind Loading

Collapsing

Red Flag Comments:

Only felt one collapse today, did notice natural activity down canyon on Fairview side on steep slopes about creek, NW facing and just below thicker conifers.

2.20 water at Mammoth /Cottonwood, temps remained around 26 degrees, snow cleared off interval board at Miller Flat was consistent throughtout.

Even though we did not trigger anything, and visibility did not allow view of higher more extreme terrain, we were happy with staying on low angle slopes and not tangle with big windloaded terrain.

Primary Concern

Primary Concern:

Wind Slabs

Probability:

Considerable

Aspect:

North

Northeast

East

Northwest

Elevation:

High

Mid

Trend:

Same

Primary Concern Comments:

Cold temps will slow healing

Secondary Concern

Secondary Concern:

Cornice Fall

Probability:

Considerable

Aspect:

North

Northeast

East

Southeast

Northwest

Elevation:

High

Trend:

Same

Secondary Concern Comments:

Again, cold temps will do little to stablize.

Elevation:

9000'

Aspect:

Northeast

Slope Angle:

snow_profile_location:

United States

39° 38' 20.9076" N, 111° 14' 45.0312" W

Comments - Photos - Videos (group 1)

More snow than we have seen in a long time, especially in December

Comments - Photos - Videos (group 2)

Levered this clean shear on density inversion, did not fail on ECT

Comments - Photos - Videos (group 3)

MF crust, no failure on ECT

Comments - Photos - Videos (group 4)

No Parking

Observed Danger Rating:

Considerable

Forecast Danger Rating:

Considerable

Snow Profile Location

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