The sky over the tree looks harmless, with no rain curtain and no storm overhead, when a blinding cloud-to-ground bolt slams into the ground about 200 to 250 metres away. Darwin storm photographer William Nguyen-Phuoc filmed this “clear-air” strike from inside his car and uploaded it to YouTube on 25 December 2010, at the height of the Top End’s storm season.
The Darwin clear-air lightning video
Nguyen-Phuoc captured the strike with a Canon 1D Mark IV fitted with a lightning trigger, a sensor that fires the shutter the instant it detects a flash. The bolt hit near the base of a tree and threw up a visible puff of dust. In his description he notes that in Darwin these bolts can strike 15 to 20 kilometres from the main storm, landing on dry ground well outside the rain.
Video: Close "clear-air" lightning bolt! - Darwin Australia, published by William Nguyen-Phuoc.
Why lightning strikes far from the storm
A thunderstorm’s electrical charge sits high in the cloud, often several kilometres above the ground. A discharge can travel sideways from the top of the storm before turning down to earth, so the channel reaches the ground in what looks like clear air. People call this a “bolt from the blue”. Because the strike lands outside the rain, it catches out anyone who judges the danger by whether it is raining yet.
The rule of thumb is simple: if you can hear thunder, you are close enough to be struck.
Darwin’s storm season and the build-up
Darwin sits in Australia’s tropical north, where the year divides into a dry season and a wet season. Australia’s Civil Aviation Safety Authority defines the wet season around Darwin as 1 October to 30 April. Its early part, the build-up, brings heat, humidity and towering afternoon storms before the first monsoon burst, which usually arrives after mid-December. Storms are most likely in the afternoon and early evening and in the early hours of the morning; during the monsoon they come more often at night.
In the build-up, organised lines of storms called squall lines can form far to the east over Arnhem Land and race west toward the city, bringing very strong wind gusts as well as frequent lightning. That spectacle makes Darwin a favourite city for lightning photographers.
Lightning safety outdoors
The U.S. National Weather Service puts it plainly: the only completely safe place in a thunderstorm is inside a substantial building or an enclosed, hard-topped vehicle, which is exactly where Nguyen-Phuoc filmed from.
- Go indoors as soon as you hear thunder, and wait 30 minutes after the last rumble before going back out.
- Open-sided shelters, tents and dugouts offer no protection.
- Keep away from isolated tall trees, high ground, open fields, water and metal fences.
- Check the forecast before heading out in storm season.
See practical lightning guidance and more lightning captured in still photographs.
Related reading
- Seven Lightning Photographs: Landmarks, Volcanoes and Exposure
- Lightning in Slow Motion: Branches and Bright Pulses
- Twenty Cloud Photographs: Shapes, Light and Atmospheric Features
- Lenticular Clouds: How a Still Shape Can Contain Moving Air
- Lake Hillier: The Landscape Behind the Pink-Lake Photograph
- A KiwiRail Train Clears Snow near Arthur’s Pass
No comments