Pileus Clouds Over Paris

July 18, 2016

PileusOverParis_IMG_9469p (3)
Photographer: Bertrand Kulik
Summary Authors: Bertrand Kulik; Jim Foster
The pileus clouds shown above atop a developing thunderstorm were photographed over Paris, France, on June 22, 2016. These smooth and often rounded clouds form above columns of rapidly rising air -- at velocities of 40 feet (about 12 m) per second or more. When the air in the updraft is close to saturation, any additional lifting may cause the air to reach the saturation point, resulting in clouds that look nothing like the cauliflower clouds below them.
Photo Details: Camera Model: Canon EOS 7D; Lens: EF100-400mm f/4.5-5.6L IS USM; Focal Length: 310mm; Aperture: ƒ/14.0; Exposure Time: 0.0050 s (1/200); ISO equiv: 100; Software: Adobe Photoshop CC 2015 (Windows).