Australian Weather Calendar: September 2016

September photograph by Kurt Ams

Kurt Ams often takes photos from the top of his apartment building in Mascot, New South Wales (south of Sydney’s CBD), but had never seen a cloud like the bubbling formation overhead on 16 September 2014. He called a friend at nearby Sydney Airport, who confirmed it was a mammatus cloud.

Mammatus, which indicates vertical motion and instability in the atmosphere, is most commonly seen at the base of cumulonimbus (thunderstorm) clouds. In this case, though, Kurt didn’t see any rain or lightning. ‘The cloud was there for about half an hour,’ he recalls, ‘and it sort of changed shapes and then moved out to the east, off the coast, and sort of disappeared… I actually don’t even think we even got a storm from it.’

Kurt used a Canon 7D with a Sigma 8–16 mm lens.