Date of Observation: 04/13/2022
Name: Eric Murrow
Zone: Northwest Mountains
Route Description: Slate River Corridor to Pittsburg. Skied into the basin on east side of Schuylkill Peak.
Observed avalanche activity: Yes
Avalanches: I observed a few small loose snow avalanches, two slab avalanches in wind-drifted terrain, and skier triggered two small wind slabs near treeline that were 12 to 18 inches deep. Poor visibility limited views into the Ruby Range.
Weather: Overcast skies, cool temperatures, and the constant westerly wind. Occasional light snowfall in the afternoon but no accumulations. During periods of improved visibility, there was a constant stream of blowing snow at upper elevations focusing on the easterly aspects.
Snowpack: At 10,500 feet I measured 12 inches of storm snow with 1.1″ SWE near Schuylkill Peak. In sheltered areas, I found storm snow without slab properties but a storm density change near the bottom of storm snow. Sheltered terrain could produce loose avalanches on very steep terrain. As soon as I found drifted terrain, I was able to produce shooting cracks up to 20 feet and easily triggered two small slabs on leeward rolls in the basin. Leeward features had drifts up to 2 feet thick. The triggered avalanches failed on the density change near the base of the storm snow.
Photos:
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Shovel Tilt Tests failed with easy taps near the bottom of the storm snow. Bonding between the new snow and old crust appeared decent.
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A small skier-triggered slab on a drifted roll.
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Another small, intentionally triggered avalanche in drifted snow.
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An example of the substantial loading going on at upper elevations on Whetstone in the evening.
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More blowing snow at upper elevations focusing on easterly aspects of Augusta and Mineral Point.
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I got one good glimpse of a Wind Slab on the east side of Schuylkill Peak. The brown crust below was quiet obvious in the bed surface. I couldn’t tell if it reached large size.
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A small natural avalanche on a cross-loaded feature below Schuylkill sub-peak.
Estimated avalanche date: 04/13/2022
Number of Avalanches: 2
Location
Location: Poverty Gulch (Pittsburg, Augusta, Baxter Basin)
Location Specific:
Start Zone Elevation: NTL: Near Tree Line
Aspect: NE
Characteristics
Trigger: Skier
Trigger modifier: Controlled
Type: Soft Slab
Failure Plane: Within storm snow
Size
Relative Size: R1 very small
Destructive Size: D1- Relatively harmless to people
Avg. crown height (inches): 16
Avg. width (feet):
Avg. vertical run (feet):
Involvements
# of people caught:
# of partial burials:
# of full burials:
Additional comments:
Estimated avalanche date: 04/13/2022
Number of Avalanches: 1
Location
Location: Poverty Gulch (Pittsburg, Augusta, Baxter 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: 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: Visibility was poor so uncertain if this reached D2 size. Brief view of crown and the obvious brown crust was exposed on the bed surface.
Estimated avalanche date: 04/12/2022
Number of Avalanches: 1
Location
Location: Poverty Gulch (Pittsburg, Augusta, Baxter Basin)
Location Specific:
Start Zone Elevation: NTL: Near Tree Line
Aspect: NE
Characteristics
Trigger: Natural
Trigger modifier:
Type: Soft Slab
Failure Plane: Within storm 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: Crown drifted in some so I coded for 4/12. Cross-loaded slope below Skooks sub-peak.
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