Why does wind blow leaves in circles?

[Josh0768]

TL;DR Summary

Why does wind blow leaves in circles?

Earlier today I realized that, when a strong gust of wind would blow through my area, it would pick up leaves off the ground and typically blow them in circular patterns, and typically the leaves would go in at least several complete circles before coming to rest back down on the ground. Why is this? How come these leaves don’t move in a translational fashion?

 

[BvU]

How come these leaves don’t move in a translational fashion?

Because the wind doesn't.
Google 'eddies' and 'whirlwind'

 

[Baluncore]

How come these leaves don’t move in a translational fashion?

You do not notice the few leaves that blow by with the wind. It is the ones that accumulate in the eddy that you focus on. When air enters an eddy behind an obstacle, or at the corner of a building, it may spiral upwards to escape from behind that obstacle. Leaves that enter the eddy may be trapped because the air in the eddy rises slower than the leaves settle.

 

[sophiecentaur]

Summary:: Why does wind blow leaves in circles?

How come these leaves don’t move in a translational fashion?

On a perfectly flat Earth with no hills or smaller obstructions, you could imagine large regions in which the air flowed in a straight line. But absolutely anything can upset that. In the same way that your hand moving across the washing up bowl causes eddies in the suds on the top, trees, fences etc etc make the same thing happen.
There's a basic principle that the physical World is becoming more and more disorganised (taken as a whole) and turbulence is always likely to occur in moving fluids.