Australia Weather News

Hundreds of images captured by an orbiting weather satellite and stitched together by the ABC show the scale and destructive force of the Victorian bushfires.

More than 400,000 hectares of land has been burnt, hundreds of structures destroyed and a man killed since extreme heat and high winds fuelled catastrophic fire conditions.

At its peak, there were several major fires and data from Victorian emergency and fire authorities shows more than 100 separate burnt areas since January 5.

Some of those areas, hit by the huge Longwood and Walwa bushfires, are more than 100,000 hectares, while others are less than a hectare.

David Bowman, a professor of pyrogeography and fire science from the University of Tasmania, said the Victorian fires appeared to be a mirror image of the Black Summer fires.

"This is a different scenario than the previous fire disaster we had in 2019-20 when the eucalypt forests were bone dry and they were the things burning and there wasn't a lot of fuel in the rural landscape because it'd been a prolonged drought," he said.

"This seems to be, at the moment, more of a grassland story right now, where the rural lands are burning because we've had good wet years."

Professor Bowman, who looked over the satellite imagery collected by ABC News, said this could be seen in the image below of the Longwood fire. He said the "long tentacles of fire" were a sign this blaze was largely in rural landscapes.

"It's a strongly wind-driven fire and wind-driven fires often burn along corridors, and then they can coalesce on the flanks," he said.

The following sequence was captured by the Japan Meteorological Agency’s Himawari weather satellite. It maintains a fixed view over several countries, including Australia, and captures images every 10 minutes.

ABC News stitched together hundreds of these images to create a detailed, statewide view of how the fire emergency unfolded.

These first images show the Walwa fire near the Victoria and New South Wales border in its early stages on January 7. 

Weather records for the nearby town of Albury show temperatures peaking at 41.1 degrees Celsius. It was the 11th consecutive day above 30C.

By late afternoon, smoke can be seen from the Longwood fire, close to the Hume Highway.

The following day, as temperatures again soared into the 40s, the Walwa fire is emitting a white, fluffy cloud.

Jason Sharples, professor of bushfire dynamics at the University of NSW, said this was a sign the fire was generating pyrocumulus and, later, pyrocumulonimbus clouds — meaning the fire was creating its own weather system, the latter of which can cause lightning strikes.

On Friday, January 9, many areas were headed for a third day in a row of temperatures above 40C.

But as at least one weather station recorded wind gusts of more than 110 kilometres per hour in western Victoria, fires erupted across the state. Thick plumes of smoke poured from the fires near Walwa and Longwood, and from a new fire Big Desert Wilderness Park, near the South Australian border.

Smoke can also be seen near Mount Darling in the Alpine National Park and Harcourt in central Victoria. Other fires are shrouded in clouds. 

By the evening, thick plumes of smoke and ash blanketed Melbourne.

Through the clouds, the first sign of two large fires in the Great Otway National Park near Colac in the state’s west can be seen. 

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By Sunday, temperatures had eased and winds had dropped, but authorities continued to issue emergency alerts as fire crews battled to get on top of the statewide disaster.

Cattle farmer Max Hobson was identified as the first fatality. He was killed in the Longwood fire near Seymour.

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Twelve major fires continued to burn across the state on Monday.

By the following day, all emergency warnings for fires across the state had been downgraded.

Professor David Bowman said that, because many of the fires appeared to have burnt rapidly through grassland, it made for difficult firefighting conditions.

"You can't fight these things in the same way you fight a forest fire because they're travelling so quickly with high winds. Everything you're trying to do was being controlled by the wind," he said.

Professor Bowman said, if heatwave conditions continued in Victoria, the eucalyptus forests would dry out and could potentially ignite in February or March.

"That's what I would be worrying about," he said.