Avalanche: Whitney Basin 1/19/2011

Observer Name:

Grant Helgeson / Ted Scroggin

Observation Date:

01/21/2011

Occurrence Date:

01/19/2011

Occurrence Time:

Morning

Region:

Whitney Basin
Uintas

Location Name:

Double Hill, Super Bowl, Thousand Peaks

Location

40° 50' 19.4964" N, 111° 0' 51.9912" W

Avalanche Characteristics

Elevation:

Unknown

Elevation Range Maximum:

10800'

Elevation Range Minimum:

10000'

Aspect:

Northeast

East

Southeast

and steeper

Slope Angle:

Trigger:

Natural

Avalanche Type:

Soft Slab

Weak Layer:

New Snow/Old Snow Interface

Depth (avg):

10"

Depth Range:

8" to

14"

Width:

Unknown

Width Range:

200' to

500'

Vertical:

Unknown

Vertical Range:

200' to

600'

General Comments

Very early Wednesday morning we received about 8" of new snow accompanied by vigorous winds out of the W, sustained at 40 mph gusting as high as 60 mph. These winds quickly formed sensitive wind slabs which led to a natural avalanche cycle above treeline on E, SE & NE facing slopes shortly thereafter. Ted & I found three different avalanches associated with this cycle. Our investigation revealed that the slabs were running on the previous snow surface, the rain crust/rime combo. We were able to consistently indentify intact surface hoar a few inches below the bed surface. The surface hoar was not involved in this avalanche cycle.

Here Ted works his way up the Double Hill avalanche: Size 1.5, 200' x 200' x 8" Terminus: Mid track

General Comments 2

Video 2:

General Comments 3

Size 2, 500' x 600' x 1' Terminus: Top of Runout. Super Bowl area, just below Windy Peak.

General Comments 4

E - SE pocket 100' x 200' x 8" Terminus: Upper Track.

Javascript is required to view this map.