This images sweeping cloud affect was achieved using a special Lee filter called a ten stop to slow the shutter speed of the camera.
Now for those of you that understand the technical side of photography, this is how it was achieved.

The first thing you have to do is set your exposure, shutter speed, manual focus and set camera on Colour Temperature of (10000 Kelvin) before inserting the Lee special ten stop filter in the Lee Filter holder mounted on the front of the lens and pressing the shutter.
Shutter set at 6.6min @ f16 iso 200

Ref: DP_MG_9072

Location: Arundel, West Sussex

Photographer: Derek Payne