Australian Weather Calendar - February 2014

February photograph by Geoff Wheeler

Cumulonimbus framed by gold and blue

This thunderstorm was generated by a low pressure trough—often known as an easterly, or inland, trough— extending through central Queensland and central New South Wales. This area of low pressure marks the boundary between warm, moist air and cool, dry air. The cool air can push under the warm air and lift it, causing water vapour to condense and form clouds. While capturing the 'weather' is essential for a photograph to have any chance of appearing in the Bureau calendar, Geoff Wheeler of Dubbo had greater artistic ambitions when he spotted a 'spectacular' cloud near Gunnedah: he waited until he could frame it in a canola field, a hill and a windmill.

Diagram