Yesterday we had a small snow blizzard. I photographed the trails of the snow as it was blown past a street light near my home. It is amazing to see the turbulence patterns in the wind. Normally these would be invisible.

Using the size of the lamp, the shutter speed and the trail length I can make an estimate of the wind speed:

slow = 1 m/s = 3.6 km/h

fast = 4.8 m/s = 17.2 km/s

This is Beaufort scale 1-3. This is much less than I would expect, it looked much more stormy yesterday. But it also matches yesterdays weather forecasts.