Date of Observation: 03/11/2023
Name: Eric Murrow
Zone: Southeast Mountains
Route Description: Lower Anthracite Mesa from Washington Gulch Trailhead.
Observed avalanche activity: Yes
Avalanches: A few natural storm slab avalanches on east and northeast aspects, D1 – D1.5. Intentionally skier triggered a moist Loose avalanche on a southeast slope below treeline.
Weather: Mostly cloudy skies, about 20 inches of storm snow, light to moderate winds, and mild air temps. Just afternoon there was a period of ‘green housing’ from the sun poking through thin clouds that quickly warmed, settled, and wet snow surfaces on the south half of the compass.
Snowpack: While moving through northeast, east, and southeast aspects below treeline we experienced few signs of instability outside of the natural Storm Slabs that ran during a period of intense snowfall earlier in the morning. On east-facing terrain, we produced a few muffled collapses during a period of strong ‘green-housing’ while surfaces were moist (nearly wet). If I skinned above my partner’s skin track, I was able to produce some ski-length cracks above the established skin track. Test results on an east slope produced an ECTP 28 +1 result and ECTN within the storm snow (see photo). While traveling over a southeast slope, the storm snow had settled and moistened/wetted to a dense, manky 10 inches ( see photo).
Photos:
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Test profile from an east-facing slope below treeline.
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Moist/wetting manky snow on slopes with any southerly component below treeline in this area.
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Minor cracking on a mid-storm layer.
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A wet/moist loose avalanche on a southeast slope. The 20 inches of storm snow settled to a very dense 10 inches by 130pm from mild temps and some solar.
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An example of a Storm Slab avalanche that ran early in the morning near the Washington Gulch Trailhead.
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Another Storm Slab avalanche that ran early in the morning by Meridian Lake.
Avalanche Report #1
Estimated avalanche date: 03/11/2023
Number of Avalanches: 2
Location
Location: Washington Gulch (Elkton, Coneys, Meridian Lake)
Location Specific:
Start Zone Elevation: BTL: Below Tree Line
Aspect: NE
Characteristics
Trigger: Natural
Trigger modifier:
Type: Soft Slab
Failure Plane: Within storm 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:
Avalanche Report #2
Estimated avalanche date: 03/11/2023
Number of Avalanches: 1
Location
Location: Washington Gulch (Elkton, Coneys, Meridian Lake)
Location Specific:
Start Zone Elevation: BTL: Below Tree Line
Aspect: E
Characteristics
Trigger: Natural
Trigger modifier:
Type: Soft Slab
Failure Plane: New/Old interface
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:
Avalanche Report #3
Estimated avalanche date: 03/11/2023
Number of Avalanches: 1
Location
Location: Washington Gulch (Elkton, Coneys, Meridian Lake)
Location Specific:
Start Zone Elevation: BTL: Below Tree Line
Aspect: SE
Characteristics
Trigger: Skier
Trigger modifier: Controlled
Type: Wet Loose
Failure Plane: New/Old interface
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:
6090