We can navigate using both snow and the absence of snow, zones known as ‘snow shadows’.
There are two types of snow shadow, those caused by sun and shade and those caused by wind and shelter. Here we will focus on some of the patterns caused by the wind. (There is a page for more information about snow shadows compasses caused by sun and shade).
Snow can fall vertically, but most of the heaviest snow comes in with a frontal weather system and this is always accompanied by significant winds.
Typically these winds blow strongly from one direction and this leads to patterns forming as the snow reaches the ground. The snow will get plastered onto the side of any obstacles, like trees, forming snow strips that can be used to navigate.
But, logically, whenever snow sticks to the side of an object like a tree, it means there must be an area that that snow is not reaching. For every snow accumulation, there must be a ‘snow shadow’, a place that has light or no snow cover.
In the video above we can see how the snow sticks to the thin young tree stump. But we can also notice that there are large areas on the track where the snow couldn’t reach, these are snow shadows. They only exist because there is dense cover, in the form of yew trees and others, stopping the snow from reaching those areas.
Once we have tuned into the direction of the wind that brought the snow, we find both of these patterns can be used to navigate.
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