4.2.2 Snow redistribution by wind

New event: Wind

A windstorm sweeps through the area six days after the initial snowfall, with speeds up to 18 m/s (35 kt). Before we examine its impact on the snowpack, we'll take a general look at wind and snowpack.

Photograph of people being blown by strong winds during a snowstorm

The redistribution of snow by wind is a critical aspect of snowpack evolution. Even in relatively flat terrain, strong winds can cause widely varying snow depths in adjoining areas. While a flat, open, wind-blown area might be snow-free, deep snowdrifts can surround obstacles or form in small terrain depressions. (That's why it's important to choose a representative location when measuring snow depth, avoiding scoured areas or snowdrifts.)

Wind can transport snow when wind speeds are above ~5 m/s (~10 kt). This threshold depends on the characteristics of the snow surface though. Weaker winds can move low-density snow whereas older, hardened snow surfaces may only begin to move with much stronger winds.