Encore - Roll Cloud off Coast of Brazil

May 05, 2018


Today and every Saturday Earth Science Picture of the Day invites you to rediscover favorites from the past. Saturday posts feature an EPOD that was chosen by viewers like you in our monthly Viewers' Choice polls. Join us as we look back at these intriguing and captivating images.

Photographer: Capt. Andreas M. van der Wurff
Summary Authors: Capt. Andreas M. van der Wurff; Jim Foster

February 2012 Earth Science Picture of the Day Viewer's Choice The photo above showing a sinister looking roll cloud was taken aboard ship while en route from Paranagua, Brazil to Montevideo, Uruguay. A cloud feature like this isn't something you would want to run into on the open sea or on a crowded highway, but roll clouds (arcus cloud) aren't necessarily a presage of severe weather. They most often form along the leading edge of a mature thunderstorm in the relatively cool air associated with the storm's downdraft; however, they're detached from the storm itself and may be seen to roll or tumble along their horizontal axis. Photo taken on February 6, 2012.