Avalanche Tool (Terrain Layer)

Our Avalanche tool is one of several Terrain Layers designed to help you better understand the terrain you will be traveling through. All of the Terrain Layers are available on both FATMAP app and web platforms. For Explore members, they are available offline with any downloaded map, no need to download them separately, 

Unlike the Gradient layer, our Avalanche layer shows only the slope gradients where an avalanche is likely to release, from 25° (yellow) to 45°+ (dark red). Above 45°, avalanche release is less likely, however there are typically other hazards such as cliffs.

Note that the release point of an avalanche is not the same as the trigger point. A skier can be traveling across a gentle slope and remotely trigger an avalanche on a nearby steeper slope, which will travel towards them. It is therefore essential to consider not only the gradient of the path you will travel, but all of the slopes around you. Be aware also of any terrain traps or cliffs below your planned path of travel that could worsen the consequences of being caught in an avalanche. 

Colour bands and the Werner Munter reduction method

The gradient colour bands have been chosen to correlate with the Elementary Reduction Method developed by Werner Munter from avalanche statistics in Switzerland. This method provides simple rules that would have avoided the majority of historical avalanche fatalities if they had been followed. Using these rules in your route planning will help you stay safe without needing to be an avalanche expert. It does not eliminate the need to look out for warning signs in the terrain! Bear in mind that the statistics used to develop this method are for a European snowpack, in other parts of the world the method may not be applicable. 

The Elementary Reduction Method in its most basic form is as follows:

• low danger level (1): avoid slopes steeper than 40°
• moderate danger level (2): avoid slopes steeper than 35°.
• considerable danger level (3): avoid slopes steeper than 30°.
• high danger level (4): stay on marked and secured runs, or in very gentle terrain, well away from slopes >30°
• extreme danger level (5): not a good day for skiing!

More information can be found here. 

Avalanche safety advice 

FATMAP is designed to help the informed skier or boarder make decisions by providing detailed information about the terrain. This is only one part of your decision to cross a slope, other important factors include the snow pack, time of day, travel techniques, weather, human factors... We therefore strongly recommend that you take an avalanche safety course to educate yourself about avalanche risk if you have not already done so!