Date of Observation: 02/28/2022
Name: Eric Murrow
Zone: Southeast Mountains
Route Description: Standard Snodgrass up-track and descended 3rd bowl area.
Observed avalanche activity: Yes
Avalanches: Lots of natural activity from the cycle last week. Most ran early in the storm with crowns well filled in and a few that ran towards the end. Many slopes greater than 35 degrees ran naturally, but not all start zones had evidence of recent avalanche activity. I suspect some features endured the loading event due to previous skier traffic. I skier-triggered a tiny loose avalanche on a steep, below treeline feature on southeast aspect at 1pm. Numerous small wet loose avalanches were visible on the east side of Gothic Mountains. They all began from rocky features; I’m uncertain if they occurred today or yesterday.
Weather: Clear skies and warm temperatures. Calm winds below treeline.
Snowpack: Southerly slopes soften before noon and I was able to produce a small wet loose avalanche at 1 pm. The top few inches were wet with couple inches of moist snow before the old crust.
On northerly terrain, I experienced a few moderately-sized collapses in low angle meadows. The slab resting above the February near surface facets was around 18″ thick and up to 1 finger hard. Two test profiles produced moderate propagating test results (ECTP 14,16). The weak layer is about 6 inches thick of fist hard 2mm facets. Signs of instability were less common than expected, but many lower angled slopes I traveled across appeared to have shattered during the loading event so that may have reduced the signs of instability. Surfaces hoar was present on N and NE slopes around 3-5mm in size.
Photos:
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Wet Loose avalanche on Gothic Mountain. Might have ran on Sunday 2/27 or Monday 2/28. All appeared to start from rocky terrain features where the snow warmed more than open slopes.
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I was able to trigger this small wet avalanche around 1 pm on a southeast slope.
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Old, natural avalanches from last week on north and northeast aspects.
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More natural avalanches from last week on shady slopes below treeline.
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Another slope that avalanched during the natural cycle. The steep feature on the top left appeared to be intact.
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Test profile from a northeast slopes indicating human triggered avalanches remain a concern on shaded slopes.
Estimated avalanche date: 02/23/2022
Number of Avalanches: 6
Location
Location: Snodgrass
Location Specific:
Start Zone Elevation: BTL: Below Tree Line
Aspect: NE
Characteristics
Trigger: Natural
Trigger modifier:
Type: Soft Slab
Failure Plane: Old snow
Size
Relative Size: R1 very small
Destructive Size: D1.5
Avg. crown height (inches): 12
Avg. width (feet):
Avg. vertical run (feet):
Involvements
# of people caught:
# of partial burials:
# of full burials:
Additional comments: Early running slides.
Estimated avalanche date: 02/23/2022
Number of Avalanches: 3
Location
Location: Snodgrass
Location Specific:
Start Zone Elevation: BTL: Below Tree Line
Aspect: N
Characteristics
Trigger: Natural
Trigger modifier:
Type: Soft Slab
Failure Plane:
Size
Relative Size:
Destructive Size: D1.5
Avg. crown height (inches): 12
Avg. width (feet):
Avg. vertical run (feet):
Involvements
# of people caught:
# of partial burials:
# of full burials:
Additional comments: Early running avalanche during last cycle
Estimated avalanche date: 02/24/2022
Number of Avalanches: 1
Location
Location: Snodgrass
Location Specific:
Start Zone Elevation: BTL: Below Tree Line
Aspect: NE
Characteristics
Trigger: Natural
Trigger modifier:
Type: Soft Slab
Failure Plane: Old snow
Size
Relative Size: R1 very small
Destructive Size: D2 – could bury, injure, or kill a person
Avg. crown height (inches): 18
Avg. width (feet):
Avg. vertical run (feet):
Involvements
# of people caught:
# of partial burials:
# of full burials:
Additional comments: Later running avalanche
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