Australian Weather Calendar: September 2018

September photograph by Peter Nunn

Peter Nunn was returning to Alice Springs from Simpsons Gap late on 22 January 2017. He spotted a storm cell to the south–triggered by daytime heating, moisture in the air and instability associated with a low pressure trough across the centre of Australia. He stopped at a favourite vantage point to watch the storm develop in the light of the setting sun.

Thunderstorms form when converging surface winds cause warm, humid air to rise rapidly through the atmosphere.