Date of Observation: 03/08/2022
Name: Irwin Guides
Zone: Northwest Mountains
Route Description: Viewed from Irwin Tenure
Observed avalanche activity: Yes
Avalanches: E bowl anthracites observed what was most likely a natural WS from
Irwin in the AM D1 potentially?
E face Ruby/Owen ridge above green lake. There was a natural wind slab 100′
X 500 below the ridge observed in the AM, then sometime after 1400 it ran again failing higher on the slope.
2-3′ X 200′ X 800′ almost to green lake.
Weather:
Snowpack: 3″ of settlement since the storm ended. No signs of instability after testing the PS structure on the west wall.
Photos:
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Photo submitted via social media by a different user, who reported the wind slab in East Bowl was there this morning.
Estimated avalanche date: 03/07/2022
Number of Avalanches: 1
Location
Location: Lake Irwin (Robinson Basin, Owen, Ruby)
Location Specific:
Start Zone Elevation: ATL: Above Tree Line
Aspect: E
Characteristics
Trigger: Natural
Trigger modifier:
Type: Soft Slab
Failure Plane:
Size
Relative Size: R1
Destructive Size: D1.5
Avg. crown height (inches):
Avg. width (feet):
Avg. vertical run (feet):
Involvements
# of people caught:
# of partial burials:
# of full burials:
Additional comments:
Estimated avalanche date: 03/08/2022
Number of Avalanches: 1
Location
Location: Lake Irwin (Robinson Basin, Owen, Ruby)
Location Specific:
Start Zone Elevation: ATL: Above Tree Line
Aspect: E
Characteristics
Trigger: Natural
Trigger modifier:
Type: Soft Slab
Failure Plane:
Size
Relative Size: R2 small
Destructive Size: D2 – could bury, injure, or kill a person
Avg. crown height (inches):
Avg. width (feet):
Avg. vertical run (feet):
Involvements
# of people caught:
# of partial burials:
# of full burials:
Additional comments:
Estimated avalanche date: 03/08/2022
Number of Avalanches: 1
Location
Location: Anthracite Range
Location Specific:
Start Zone Elevation: NTL: Near Tree Line
Aspect: E
Characteristics
Trigger: Natural
Trigger modifier:
Type: Soft Slab
Failure Plane:
Size
Relative Size: R1 very small
Destructive Size: D1- Relatively harmless to people
Avg. crown height (inches):
Avg. width (feet):
Avg. vertical run (feet):
Involvements
# of people caught:
# of partial burials:
# of full burials:
Additional comments:
5469
