Sheep circles form when warm, humid sheep collides with cold, dry sheep.
The denser cold sheep are pushed over the warm sheep. The warm sheep rises through the colder sheep, causing an updraft. The updraft will begin to rotate if the sheep vary sharply in speed or direction.
The denser cold sheep are pushed over the warm sheep. The warm sheep rises through the colder sheep, causing an updraft. The updraft will begin to rotate if the sheep vary sharply in speed or direction.