Obs-Snow Profile: Skyline 1/20/2012

Observer Name:

Matt Selman

Region:

Skyline

Observation Date:

01/20/2012

Location or Route:

The Wall, East Face

Weather

Sky:

Scattered

Wind Direction:

Southwest

Wind Speed:

Light

Weather Comments:

Mostly cloudy skies clearing to partly cloudy, light winds out of the southwest with gusts to 10 mph.

Snow Characteristics

New Snow Depth:

New Snow Density:

Medium

Snow Surface Conditions:

Dense Loose

Snow Characteristic Comments:

Five centimeters of new, light-to-medium-density snow found in areas sheltered from wind.

Red Flags

Recent Avalanches

Wind Loading

Collapsing

Red Flag Comments:

Observed recent (< 1 day) avalanche activity on nearby Lineer Ridge/GE Hill. Full report by Darce Trotter and Steve Cote: http://utahavalanchecenter.org/avalanche_ge_hill_proper_1202012

Primary Concern

Primary Concern:

Wind Slabs

Probability:

High

Aspect:

Northeast

East

Elevation:

High

Trend:

More Dangerous

Primary Concern Comments:

Winds accompanying the ongoing storm system are moving the new snow as quickly as it falls. Underlying layers (faceted snow) have proven to be unsupportable. The weight of a skier will easily start and propagate cracks in deposited layers. In a wind-loaded area, an attempted ECT failed on depth hoar (almost to the ground) while cutting the back wall of the column.

Elevation:

9400'

Aspect:

Northeast

East

Slope Angle:

snow_profile_location:

United States

39° 38' 58.9776" N, 111° 20' 7.0008" W

Comments - Photos - Videos (group 1)

Profile of snowpack in an undisturbed, wind-sheltered area. If the storm forecasted for 1/21/2012 pulls through, this gives you an idea what kind of lurking demons will be buried.

Comments - Photos - Videos (group 2)

Walking out onto a short wind-loaded test slope, a fracture started, propagated, and slid a short distance under my skis.

Comments - Photos - Videos (group 3)

Close-up of weak layer (buried facets). Crystal size <0.5 cm.

Comments - Photos - Videos (group 4)

Attempted ECT in wind-loaded pack. Column sheared cleanly on facets near the ground when the back wall was cut away.

Observed Danger Rating:

High

Snow Profile Location

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