Date of Observation: 03/08/2022
Name: Zach Guy
Zone: Southeast Mountains
Route Description: Traveled on flat or east facing terrain to 11,400 ft. in West Brush Creek
Observed avalanche activity: Yes
Avalanches: Good views of lots of terrain in West Brush up towards White Mtn, and I did not see any natural activity from this past storm. However, there were a handful of small soft slabs that ran recently near valley bottom near the confluence of Middle and West Brush Creek. One of them appeared to be remotely triggered today by a snowmobile. The rest ran naturally sometime in the past couple days on east and north aspects.
Weather: Mostly clear skies, calm winds where we traveled; occasional light drifting on high peaks like Teo. Cold day.
Snowpack: 12″ of settled storm snow in the Union Chutes area. We saw numerous shooting cracks while snowmobiling flat terrain in valley bottom, a couple of them shook willows or small tree branches. The most interesting one I triggered from across a creek; the failure must have crossed a snow bridge and collapsed the opposite slope (east facing). On skis, we produced two collapses on east facing slopes around 10,000 ft. Both collapses required some hard stomps to punch through the mid-slab crust first. Most of the steep terrain around here avalanched with the last cycle. The one bedsurface we traveled on did not appear to have enough slab to be problematic; it did not produce signs of instability on slope angles up to 40 degrees. I also tested a few south and west facing terrain features without any signs of instability. Obvious signs of instability also waned as we climbed to near treeline elevations on E/NE, although the structure is clearly poor from pole probing.
Photos:
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This slide appeared to be remotely triggered by a snowmobile today. The crown wasn’t there this morning.
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I triggered this shooting crack on an east facing slope from flat terrain on the opposite side of the creek.
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A natural slab that likely ran yesterday.
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One of two recent naturals on an east facing, wind drifted feature.
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Hasty profile at the site of a rumbling collapse triggered by stomping with skis.
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Same location, photo this time.
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THE SANDBOX LAYER! Why am I yelling? Because it’s ugly as sin. It literally falls out of the pit while shoveling, just like sand.
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Another collapse was on an east facing slope with a hint of south to it (ESE). The 3/5 crust was thick enough that getting a collapse seemed improbable, but I got one by jumping on an adjacent terrain feature that was slightly tilted to the northwest, thus no crust.
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Good views of the most suspect terrain and no recent avalanches, just lots of old crowns and debris from the 2/23 cycle.
Estimated avalanche date: 03/08/2022
Number of Avalanches: 1
Location
Location: Other: Add text
Location Specific: Strand Hill
Start Zone Elevation: BTL: Below Tree Line
Aspect: N
Characteristics
Trigger: Snowmobiler
Trigger modifier: Remote
Type: Soft Slab
Failure Plane: Old snow
Size
Relative Size: R2 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: This definitely ran today, it was not there this morning. There is a snowmobile track within a few hundred feet of the avalanche so I’m guessing it was remotely triggered.
Estimated avalanche date: 03/07/2022
Number of Avalanches: 2
Location
Location: Other: Add text
Location Specific: Strand Hill
Start Zone Elevation: BTL: Below Tree Line
Aspect: N
Characteristics
Trigger: Natural
Trigger modifier:
Type: Soft Slab
Failure Plane: Old snow
Size
Relative Size: R2 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:
Estimated avalanche date: 03/07/2022
Number of Avalanches: 2
Location
Location: West Brush Creek
Location Specific:
Start Zone Elevation: BTL: Below Tree Line
Aspect: E
Characteristics
Trigger: Natural
Trigger modifier:
Type: Soft Slab
Failure Plane: Unknown
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: Wind drifted feature from recent northwest winds. Could have failed within storm snow, interface, or old snow.
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