Taken on May 26th, 2013, this was a dissipating low precipitation thunderstorm near Broken Bow, Nebraska, that produced one of the best lightning shows I have ever witnessed in my storm chasing career. Even more beautiful was when the lightning lit up these incredible mammatus clouds in the night sky. These type of clouds are often associated with severe thunderstorms, and their ominous and foreboding appearance is a message to all that severe weather may be on its way.
Photo credit: © Anne Goforth/National Geographic Photo Contest
Cave diver Dave Bunnel, 61, captured these stunning images of him diving into Mexico’s El Sotano de las Golodrinas, The Basement of Swallows — - a 1,200-foot-deep hole in Mexico that is so deep, clouds form inside. The pit was first descended in December of 1967 by a trio of Americans. Its total depth is 1,638ft although the final few hundred feet accessible are only accessible through a pit series called The Crevice. It gets its name, the Basement of Swallows, thanks to the birds that fly above its opening.
Photo credit: Dave Bunnel