Date of Observation: 03/12/2022
Name: Irwin Guides
Zone: Northwest Mountains
Route Description: Irwin Tenure: Upper Upper West Wall
Observed avalanche activity: Yes
Avalanches: These were largely unreactive to ski cuts but reactive to AE, most failing on the suncrust beneath this last storm cycle.
Field of Screams HS-AE-R1-D1.5-O FC (30cm x 30m x 200m)
Castle Valley Left HS-AB-R1-D1-O FC (70cm x 10m x 100m)
Castle Valley Right HS-ASc-R1-D1-O FC (20cm x 10m x 220m) ski cut at the top.
Photos:
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Estimated avalanche date: 03/12/2022
Number of Avalanches: 2
Location
Location: Lake Irwin (Robinson Basin, Owen, Ruby)
Location Specific:
Start Zone Elevation: NTL: Near Tree Line
Aspect: W
Characteristics
Trigger: Explosive
Trigger modifier:
Type: Hard Slab
Failure Plane: Old snow
Size
Relative Size: R1 very small
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: 03/12/2022
Number of Avalanches: 1
Location
Location: Lake Irwin (Robinson Basin, Owen, Ruby)
Location Specific:
Start Zone Elevation: NTL: Near Tree Line
Aspect: W
Characteristics
Trigger: Skier
Trigger modifier: Controlled
Type: Hard Slab
Failure Plane: Old snow
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:
5485
