Mammatus clouds are strange, pouchlike protrusions that can form on the underside of a thunderstorm's anvil-shaped cloud-top. They are caused by cold air sinking downwards and are often a sign of strong storms. This image is part of a sequence I was able to shoot after following a squall-line over the Cambrian Mountains late on a May evening in 2003.
Product number 2000-2009855. Email me to enquire about this image: click HERE.