Roll Cloud off Coast of Brazil
Tuesday, 06 March 2012 15:08
The photo above showing a sinister looking roll cloud was taken aboard ship while en route fromParanagua, 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 maturethunderstorm 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.