California Avalanche Map Layers

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"What's the danger?" Here are autogenerated DEM Shading rules for each advisory zone that allow for quickly adding avalanche danger, problems, and sun angle layers to CalTopo maps. Reports sourced from avalanche.org.

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Digital Elevation Model (DEM) shading let's you create custom shading schemes based on elevation, slope, aspect and tree cover.

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Avalanche Report

The selected elevation bands are not meant to be exact, but represent a characteristic of the terrain which varies locally.

The highest band, ATL (Above Tree Line), typically includes alpine areas beginning as the treeline transitions into open slopes extending to ridges and peaks.

The middle band, NTL (Near Tree Line), is typically a narrow transition zone between dense forests and treeless alpine areas.

The lowest band, BTL (Below Tree Line), typically extends from valley floors or snowline to near treeline.

Adjusting bands

The default elevation bands may not be accurate for the current zone, you can adjust the bands by dragging the sliders.

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Usage

You'll find that Terrain Modeling in the left pane will show layers that can be turned on and edited. The right pane will show Custom Layers that can be toggled on or off.

Select A Zone: Bridgeport Avalanche Center Eastside Region Mount Shasta Central Sierra Nevada

Avalanche Report

Report not available. See BAC for more information.

Avalanche Report

Pre-populated CalTopo Map

2025-01-21 Avalanche Danger

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• Low danger (above 10001')
• Low danger (7801' to 10000')
• Low danger (below 7800')

Issued at: Monday, January 20, 2025 7:00AM
Issued by: ESAC

Avalanche Report

Pre-populated CalTopo Map

2025-01-21 Avalanche Danger

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• Low danger (above 8701')
• Low danger (6201' to 8700')
• Low danger (below 6200')

Issued at: Monday, January 20, 2025 6:30AM
Issued by: MSAC

Avalanche Report

Pre-populated CalTopo Map

2025-01-21 Avalanche Danger

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• Low danger (above 8701')
• Low danger (6201' to 8700')
• Low danger (below 6200')

Issued at: Monday, January 20, 2025 6:45AM
Issued by: SAC

Zone

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