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

Loose wet instability on Rubicon Peak.

Location Name: Rubicon Peak Region: West Shore Area Observation Date & Time: Friday, April 20, 2018 - 10:30
Location: 38.989073, -120.133320 See map: CalTopo	Is this an Avalanche Observation?: No Conditions Alerts: Avalanche Activity Rapid or Prolonged Warming Rapid or Prolonged Warming›Rollerballs / Pinwheels Rapid or Prolonged Warming›Strong Sunshine Rapid or Prolonged Warming›Warm Temperatures Terrain Alerts: Slopes Steeper than 30 degrees Terrain Matches the Advisory

Observation made by: Forecaster

Tabs

Observation

Description of Snow, Weather, and Avalanche Conditions:

Rapid warming conditions and signs of loose wet instability in the form of human triggered roller balls present in sun exposed areas on all aspects by 10 am. These roller balls were easy to create up to the highpoint of travel below the summit pinnacle at 9,040'. Loose wet avalanches involving the top 4 to 6 inches of the snowpack (the recent storm snow) were easy to skier trigger on all test slopes steeper than about 35 degrees on N-NE-E aspects at all elevations traveled from 10:30 am onwards.

Human triggered roller ball showing developing instability. N aspect, below treeline, ~7,900', 10 am.

Easily skier triggered loose wet avalanche on test slope. E aspect, at treeline, 9,040', 10:40 am.

Snowpack Details

Persistent Weak Layers:

Not observed

Terrain Details

Terrain: elevations:

Near Treeline

Below Treeline

Terrain: aspects:

Weather Details

Elevation of Observation:

7000 - 8000 ft.

8000 - 9000 ft.

Blowing Snow:

None

Wind Direction:

Northeast

Wind Speed:

Light

Sky Cover:

Clear

Precipitation:

None

Air temperature:

Above Freezing

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

Loose wet instability on Rubicon Peak.

Conditions Alerts:

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

Loose wet instability on Rubicon Peak.

Conditions Alerts:

Tabs

Search form

Follow Us

Sponsors: