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Cornice fall on Andesite Ridge

Location Name: Andesite Ridge Region: Donner Summit Area Observation Date & Time: Sunday, March 25, 2018 - 12:00
Location: 39.349166, -120.364838 See map: CalTopo	Is this an Avalanche Observation?: Yes Conditions Alerts: Avalanche Activity Other Signs of Instability (cracking, whumpfing, collapsing) Terrain Alerts: Slopes Steeper than 30 degrees Obvious Slide Path Trigger Points

Observation made by: Public

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Observation

Description of Snow, Weather, and Avalanche Conditions:

We intentionally triggered a couple of cornices on test slopes. They failed pretty easy with a light kicks from the ski tips. Cracks propagated up to ten feet and cornice chunks were up to the size of refrigerators.

Avalanche Details

Avalanche Type:

Cornice

Additional number of similar avalanches:

Trigger

Trigger:

Skier

Trigger Modifier:

Intentionally Triggered

Terrain

Start Zone Slope Angle:

35degrees

Aspect:

Northeast

Starting Elevation:

above-treeline

Size

Destructive Size:

D1 Relatively harmless to people.

Avalanche Width (Average width):

10ft.

Avalanche Length (Vertical Run):

50ft.

People Involved

Number of people caught:

Number of partial burials:

Number of full burials:

Weather Details

Elevation of Observation:

7000 - 8000 ft.

Blowing Snow:

Light

Wind Direction:

Southwest

Wind Speed:

Light

Sky Cover:

Broken - Mostly Cloudy - more than 4/8 and less than 8/8

Highest Precipitation Rate:

Very Light Snowfall (S-1 = up to .5cm /~.25 in per hour)

Precipitation:

None

Air temperature:

Below Freezing

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Cornice fall on Andesite Ridge

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Cornice fall on Andesite Ridge

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