Avalanche: Toledo Bowl 2/19/2010

Observer Name:

Hardesty and Wagner

Observation Date:

02/20/2010

Occurrence Date:

02/19/2010

Occurrence Time:

Unknown

Region:

Salt Lake
Little Cottonwood Canyon
Toledo Bowl

Location

40° 35' 47.0076" N, 111° 38' 33.4932" W

Avalanche Characteristics

Elevation:

9700'

Aspect:

South

Southwest

Slope Angle:

Trigger:

Skier

Trigger: additional info:

Unintentionally Triggered

Avalanche Type:

Soft Slab

Weak Layer:

Facets Above Crust

Depth (avg):

12"

Depth Range:

10" to

16"

Width:

70'

Vertical:

Unknown

Snow Profile

Snow Profile Comments:

Unintentional skier triggered release Friday. Timing is unknown. Wagner and I walked up Toledo to confirm that it collapsed the Feb 14 mf crust in order to fail on the faceted snow layering from Feb 8-10. Unusual to see skier triggered slides on south/southwest that collapse a stout melt freeze crust. Similarly layering responsible for naturals on Hellgate and Cottonwood draw from the 16th.

General Comments

Weaknesses found across the range from the Feb 8-10th period of high pressure, high RHs, and little wind. The late Wed/early Thurs light snowfall well preserved both surface hoar and surface facets. This has been the culprit in the bazillions of human triggered slides since the 11th or so.

It is debatable whether the number of slides triggered have been related to surface hoar. Many are confirmed, many are not - and failed at the diurnal or radiation recrystallized snow. Many have been triggered remotely. Regardless, the weaknesses formed at the same time period and will be somewhat slow to stabilize.

General Comments 2

Here's another shot looking across the bed surface to see weaknesses above the newer crust and then of course the older one.

General Comments 3

Route continued into Cardiff with no cracking or collapsing.

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