Persistent Slab Avalanche Near Castle Peak

Location Name: DLI / Castle Region: Donner Summit Area Observation Date & Time: Monday, March 30, 2020 - 16:45
Location: 39.347001, -120.305632 See map: CalTopo	Is this an Avalanche Observation?: Yes Terrain Alerts: Slopes Steeper than 30 degrees Terrain Matches the Advisory

Observation made by: Public

Tabs

Observation

Description of Snow, Weather, and Avalanche Conditions:

This avalanche was triggered by another snowmobiler in my group. It broke below the sled.

The bed surface was sugary.

Ample hangfire was left above the crown. After cutting just a few feet of the hangfire with my hands and pulling on it a little bit, a crack propagated about 50 feet and an additional few feet of hangfire slid down.

After reading the observations from Frog Lake and Castle Peak this morning, this one surprised us.

Northwest aspect, 7500 feet.

Snowpack Details

Persistent Weak Layers:

Buried

Terrain Details

Terrain: elevations:

Near Treeline

Terrain: aspects:

Avalanche Details

Avalanche Type:

Persistent Slab

Failure Plane/Weak Layer:

Old Snow

Trigger

Trigger:

Snowmobiler

Trigger Modifier:

Accidentally Triggered

Terrain

Aspect:

Northwest

Starting Elevation:

near-treeline

Size

Destructive Size:

D2 Could bury, injure, or kill a person.

Relative Size:

R3 Medium

Crown Height:

1 ft

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

Sky Cover:

Overcast - Cloudy - 8/8 covered

Sponsors:

This website is owned and maintained by the non-profit arm of the Sierra Avalanche Center. Some of the content is updated by the USDA avalanche forecasters including the forecasts and some observational data. The USDA is not responsible for any advertising, fund-raising events/information, or sponsorship information, or other content not related to the forecasts and the data pertaining to the forecasts.

Forecast Links

Subscriptions

Forecast Tutorials

Observations

Incidents

Submit Observations

Subscriptions

Remote Weather Stations

National Weather Service

Model Forecasts

Local Resources

The SAC Daily Flow

Forecast Tutorials

Other Resources

Persistent Slab Avalanche Near Castle Peak

Tabs

Sponsors:

Forecast Links

Subscriptions

Forecast Tutorials

Observations

Incidents

Submit Observations

Subscriptions

Remote Weather Stations

National Weather Service

Model Forecasts

Local Resources

The SAC Daily Flow

Forecast Tutorials

Other Resources

Persistent Slab Avalanche Near Castle Peak

Tabs

Search form

Follow Us

Sponsors: