Australian Weather Calendar

A squall line associated with a thunderstorm over Era Beach, south of Sydney.

Picture: Mr Bruce Cooper

July: From wildflowers to wild skies

Cover | Jan | Feb | Mar | Apr | May | June | July | Aug | Sept | Oct | Nov | Dec

Bruce Cooper's camera invariably carries a macro lens for targeting wildflowers in Royal National Park south of Sydney. The semi-retired financial consultant from Como and his wife Jean often spend a couple of days a week bushwalking there, intent on expanding their 4000-photograph collection covering more than 200 wildflower species. A member of the Australian Plants Society, he generally prefers photographing microstructures and orchids to weather and skies.

On 11 December 2011, after a 'poor morning's wildflower photography', Bruce and Jean raced back to their car to beat a storm front by a minute and avoid a drenching. 'There was a lot of thunder rumbling out to sea', Bruce recalls. 'We drove to the nearby ocean lookout above Era Beach to have a look, switched to the regular zoom lens I keep in the boot and started shooting in the rain. I got lucky with what we now call the 'elephant's foot' picture.'

A wall cloud normally indicates a highly organised and long-lived storm with a rotating updraft (a supercell). A wall cloud forms when rain cooled air from the downdraft of a thunderstorm is pulled into the updraft. This air becomes saturated more quickly than the initial updraft, causing the cloud base to lower.