Alice Springs residents have a massive clean-up job ahead of them after the outback town was smashed by a powerful storm over the weekend.
In just a few moments, a chaotic downburst of wind and rain knocked over trees, blew off roofs and downed powerlines.
Eyewitnesses say they were "terrified" by the ferocity of the storm's wind and rain, which lasted only three minutes.
It's just one isolated incident in a deluge of damaging weather systems wreaking havoc on much of the Australian continent, with severe flooding in New South Wales and more massive storms in South Australia over the weekend.
In the aftermath, weather experts described the storm that struck Alice Springs as a 'microburst' — a massive blast of wind strong enough to cause tremendous damage in an incredibly short amount of time.
While the official weather station recorded a top wind speed of 76 kilometres per hour, the Bureau of Meteorology (BOM) estimated wind speeds likely exceeded 100 kilometres per hour during the storm.
What is a microburst?
To understand microbursts, you first have to know about downbursts — a concentrated downdraft of abnormally high speed, capable of causing damage on the ground.
This occurs when precipitation falls into the drier air within a thunderstorm, or below it, causing the water to immediately evaporate, cooling the surrounding air in the process.
This freshly cooled air then increases in density, pushing it downwards.
A microburst is basically a downburst on a smaller scale. The BOM uses the term microburst to describe a downburst that causes damage "over an area with horizontal dimensions of less than four kilometres".
For one to occur, BOM senior meteorologist Sally Cutter says you need three things: an "unstable atmosphere", a lot of moisture in the air and a trigger.
Conditions on Saturday were just right for such a weather event, she says, with tropical moisture moving in a band over the city.
"The set-up was so that it could just dump a lot of rain," she says.
University of New South Wales researcher Professor Steven Sherwood is currently investigating microbursts and how they form.
He says the unpredictable phenomena is the result of a mass of cold air building up in a storm, which subsequently "crashes down toward the ground, attaining velocities of tens of metres per second".
"When it hits the ground, it kind of blasts out for a short period of time."
Do they happen often in the desert?
Professor Sherwood says microbursts are rare events right across the country, and — apart from cyclones — generate the most destructive winds of any weather event.
But where they form, and what exactly drives their formation, is still up for debate.
What is known is that microbursts can happen right across the Northern Territory, including in the desert.
And it's not the first time Alice Springs has experienced one either.
In 2017, a microburst was responsible for flipping a light plane upside down and tearing the roof off a hangar at the Alice Springs Airport.
Ms Cutter says the storms are difficult to forecast, with Saturday's event only forming right on the edge of Alice Springs — giving forecasters little time to issue warnings.
"It moved very, very rapidly so it didn't last that long, but it did pack a massive punch."
Does La Niña make microbursts more common?
Much of Australia is already saturated after months of above-average rainfall.
The culprit behind this wet weather is La Niña — a global climate cycle that happens when warmer waters in the Pacific Ocean move closer to Australia, bringing with it an increased likelihood of rain.
The opposite of this is El Niño, which typically results in below-average rainfall and a greater chance of drought in Australia.
And while La Niña brings more rain, Professor Sherwood says research shows these cycles aren't associated with more dramatic weather events.
"I couldn't tell you about microbursts, but we've looked at whether other extreme phenomena are strongly related to El Niño [and La Niña] finding they're not really," he says.
"I would be surprised if that was too important."
The same isn't true of tropical cyclones — the BOM typically predicts more tropical cyclones to form during a declared La Niña cycle compared with a neutral or El Niño year.
What about climate change?
There's "a lot more to be done" in terms of studying microbursts and whether climate change is making them more common or severe, Professor Sherwood says.
He recently worked on a study that found 'rainbursts' are becoming more common in the Sydney area as a result of a warming climate.
But, again, he says the research of other extreme wind events showed they weren't becoming dramatically more common with man-made climate change.
"At the moment there's no evidence it's getting worse."
What can you do to keep safe during a microburst?
Microbursts are exceedingly rare, but at the same time they can cause tremendous damage.
And being prepared and knowing what to do during a severe storm can minimise the risk of property damage or injury from flying debris.
Ms Cutter says the best precautions people can take include making sure there aren't many loose items stored outside of the home.
"Because these storms can happen so quickly, it's a good idea to just have your yard basically tidied up anyway," she says.
"So all you have to do when a warning is issued is just pick up some loose objects that may be blown around, but more importantly, make sure you shelter in a secure location ... away from windows, not under trees, in a strong area."
