New Hampshire Avalanche Map Layers

---

"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.

Show Instructions

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

---

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.

---

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: Presidential Range

Avalanche Report

Pre-populated CalTopo Map

2025-01-21 Avalanche Danger

Copy to clipboard

• Moderate danger (above 5101')
• Moderate danger (3001' to 5100')
• No rating (below 3000')

2025-01-21 Wind Slab

Copy to clipboard

• N to S aspects (above 5101')
• N to S aspects (3001' to 5100')

Issued at: Monday, January 20, 2025 6:53AM
Issued by: MWAC

Zone

Download GeoJSON

---

Change Regions: California Idaho Wyoming Oregon Alaska Montana Arizona New Hampshire Washington New Mexico Utah Colorado Canada

If you enjoyed this or found it helpful, please consider buying an espresso to keep the flow going.

Show Known Issues