This cool time-lapse clip showcases the amazing way cumulonimbus clouds form, shift, grow, and move across the sky, proving that even "ordinary" fluffy clouds are anything but placid.

She explained that what occurred was not a hurricane in the conventional sense, but rather the result of a cumulonimbus thundercloud formation that produced what is scientifically known as a ...

On the anniversary of D-Day, and a time of historic combat, Washington witnessed a day of peace in the atmosphere, on the road from spring to summer.