Cirrus Clouds

Cirrus is formed at higher levels. Although these clouds look windswept they change their shape very slowly by comparision with water clouds. Below is a wave cloud. In the distance is a more continuous layer of fibrous ice cloud called cirrostratus.

On the left is feather or leaf like cirrus. On the right is lines of cirrus along the wind. Across these and at a lower level are striations across the direction of the wind.

Contrails (aircraft condensation trails) may be spread over the sky to form a layer of artificial cirrus. Below, dust rising from a power station can be seen showing the artificial thermals.