Australian Weather Calendar: November 2020

November photgraph by Will Eades

Having a crack

For Will Eades, it was the volatile nature of the storms rolling through his hometown of Port Macquarie that sparked a passion for weather photography—particularly lightning. Beginning as a wildlife photographer before turning his attention to stormscapes, Will says the beauty of storms is that you never know what you're going to get. 'Some of the cells that form off the coast are just spectacular; we get waterspouts, shelf clouds, and the most incredible lightning. I've photographed the storms in the US and while the scale of them is like nothing else, I'd still say here in Australia we have some of the best lightning in the world.' Will says he uses the Bureau ‘s satellite viewer to see the height of a storm— 'In Port Macquarie the higher the storm, the colder it is, the more chance of lightning and hail'—which helped him capture this particular shot, recalling that the storm caused a lot of hail and damage in Sydney. With a young child at home and demands at work, Will says these days he's not out there photographing the weather as often as he'd like, but says 'if there’s a big squall line with a lot of lightning embedded in it tracking towards Port Macquarie, I’ll be there, I’ll find a way.'

The science

A shelf cloud is a low wedge-shaped cloud formation which is usually attached to a cumulonimbus, or thunderstorm, cloud – as shown in this photograph. These clouds are formed by the interaction between a downdraft of cool air coming out of the storm, and an updraft of warm air rising into the storm. As the cool air moves away from the storm, it undercuts the warm air and the shelf cloud is formed at the boundary of the two air masses. The reason for the eerie green glow visible within some thunderstorms, including this one, is still the subject of debate. It seems that the green component of sunlight is scattered preferentially in stronger thunderstorms that contain large amounts of hail and/or larger hailstones—and perhaps also water droplets.