The last avalanche forecast for the 2023-2024 season will post on April 21st. Thank you to all who contributed to the avalanche center this season through observations, volunteer time, and/or financial contributions.

Persistent Weak Layer Cold Stream

Location Name: Cold Stream Region: Cabin Creek, Deep Creek, or Pole Creek Area Observation Date & Time: Sunday, February 26, 2023 - 10:25
Location: 39.279035, -120.262481 See map: CalTopo	Is this an Avalanche Observation?: Yes Conditions Alerts: Avalanche Activity Persistent Problem Recent Loading Recent Loading›More Than a Foot of New Snow Recent Loading›Snowfall Rates of More Than 1 in/hr Terrain Alerts: Slopes Steeper than 30 degrees Obvious Slide Path Trigger Points Terrain Traps Terrain Matches the Advisory

Observation made by: Public

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Observation

Description of Snow, Weather, and Avalanche Conditions:

While ski cutting an unsupported test slope I trigged a small but deep persistent slab release on a layer of facets underlying a melt freeze from the dry period last week. The new snow over lying this layer was about 70cm in depth and propagated 20 feet on either side of me and carried me down on to the snowcat road below.

Snowpack Details

Total Snow Depth:

350cm

Persistent Weak Layers:

Buried

Terrain Details

Terrain: elevations:

Below Treeline

Terrain: aspects:

Avalanche Details

Avalanche Type:

Persistent Slab

Failure Plane/Weak Layer:

Old Snow

Trigger

Trigger:

Skier

Trigger Modifier:

Intentionally Triggered

Terrain

Start Zone Slope Angle:

35degrees

Aspect:

North

Starting Elevation:

below-treeline

7000ft

Size

Destructive Size:

D1 Relatively harmless to people.

Relative Size:

R1 Very Small

Crown Height:

3 ft

Avalanche Width (Average width):

40ft.

Avalanche Length (Vertical Run):

5ft.

People Involved

Number of people caught:

Number of partial burials:

Number of full burials:

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Persistent Weak Layer Cold Stream

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