Clouds that look like a series of breaking waves are known as ‘Kelvin-Helmholtz’ formations. They can appear at the low, middle and high cloud levels. This video, filmed from Birmingham, Alabama, US, shows a particularly low example of Kelvin-Helmholtz clouds. So dramatic were the waves that they were featured in the local news, described by reporters as the ‘tsunami clouds’. We like dialogue between the cloudspotting couple. She want’s him to call the TV weather man to ask what they are. He seems to be too busy using his power tools to put up some shelves at the same time as he’s filming them…