Date of Observation: 03/02/2023
Name: Zach Guy
Zone: Northwest Mountains
Route Description: West Elk Air flight covering most of the forecast zone. This ob highlights activity in the Northwest Mountains.
Observed avalanche activity: Yes
Avalanches: The Tuesday/Wednesday storm produced numerous wind slab avalanches, D1.5 to D2, see photos. Most of these appeared to run on Tuesday as well as a handful on Wednesday. The last pulse of the storm on Wednesday also produced many small loose avalanches and a handful of thin storm slabs involving just Wednesday’s storm snow. I spotted two fresh persistent slab avalanches that failed on old weak layers, one was a wind slab that stepped down a few feet on an east facing, windloaded ATL slope near Coffee Pot Pass, in the Southeast Mountains. The other was on a steep, shallow east facing slope near treeline on East Beckwith in the Northwest Mountains. That slope has slab avalanched at least twice this year, so it has an unusually shallow snowpack.
Weather: Clear, light winds.
Photos:
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Persistent slab on a shallow slope on East Beckwith
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Thin storm slabs on East Beckwith
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Wind slabs Robinson Basin
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Wind slab / cornice fall on Hancock
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Wind slab / cornice fall near Richmond
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Wind slab on Mineral Pt.
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Wind slabs on Purple Mountain
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Quigley Basin, Mt. Baldy
Estimated avalanche date: 03/01/2023
Number of Avalanches: 1
Location
Location: Beckwith Range
Location Specific:
Start Zone Elevation: NTL: Near Tree Line
Aspect: E
Characteristics
Trigger: Natural
Trigger modifier:
Type: Soft Slab
Failure Plane: Old snow
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: East Beckwith. Failed on old snow near the ground on a slope that is unusually shallow.
Estimated avalanche date: 02/28/2023
Number of Avalanches: 3
Location
Location: Upper Slate (Purple, Yule Pass, Paradise Divide)
Location Specific:
Start Zone Elevation: ATL: Above Tree Line
Aspect: NE
Characteristics
Trigger: Natural
Trigger modifier:
Type: Soft Slab
Failure Plane:
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: Purple Mtn. Looked D1.5, one maybe a D2.
Estimated avalanche date: 02/28/2023
Number of Avalanches: 2
Location
Location: Oh-Be-Joyful Basin
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: Richmond x 1, Hancock x 1. Both triggered by cornice fall.
Estimated avalanche date: 02/28/2023
Number of Avalanches: 1
Location
Location: Poverty Gulch (Pittsburg, Augusta, Baxter Basin)
Location Specific:
Start Zone Elevation: ATL: Above Tree Line
Aspect: N
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: Mineral / Augusta saddle
Estimated avalanche date: 03/01/2023
Number of Avalanches: 1
Location
Location: Mount Baldy
Location Specific:
Start Zone Elevation: ATL: Above Tree Line
Aspect: E
Characteristics
Trigger:
Trigger modifier:
Type: Soft Slab
Failure Plane:
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: Quiqley Basin
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