Number of tornadoes in Australia much higher than people think as experts suggest most go unnoticed

The word “hurricane” often conjures images of flying cows and storm chasers in the movie Twister or families hiding in basement shelters in the American Midwest.

For many Australians this is a weather event They engage with their own backyard.

But cyclones are actually much more common in Australia than most people think.

30 to 80 hurricanes Tornadoes are recorded every year in Australia, and weather experts say the number is likely much higher because cyclones in more remote areas often go unnoticed.

Australia has a long history of hurricanes; The reports date back to 1795, to October last year.

Tornadoes, also called volitional, dust devils, or tornadoes, are all characterized by a violently rotating column of air that forms in a cloud; The pillar must touch the ground to be considered a proper tornado.

They can last from less than a minute to more than an hour and vary in size from meters to more than 1 km wide.

The Bureau of Meteorology said winds within the hurricane could exceed 300km per hour, making them “some of the most destructive events in nature”.

“Hurricanes form when weakly rotating air near the surface is rapidly pulled upward into a cumulus or cumulonimbus cloud,” BOM said.

“As the air column rises, it stretches, increasing the speed of rotation, just like an ice skater spins faster as he pulls his arms.”

There are two main types of tornadoes in Australia: Supercell tornadoes, which form during severe storms, and non-supercell tornadoes, which form during major changes in weather conditions such as strong cold fronts.

Supercell tornadoes are most common in central and eastern NSW, southeastern Queensland and northeastern Victoria.

“This is more likely in late spring and early summer, when conditions are best for intense storms,” BOM said.

Several major tornado outbreaks have already hit the United States this year, including 10 tornadoes that damaged more than 100 homes in the Midwest in April.

Tornado outbreaks can also occur in Australia, although more rarely.

At least on September 28, 2016 Seven tornadoes cause statewide power outages in South Australia.

Why are cyclones in Australia so difficult to measure?

“The destructive nature of a hurricane makes measuring the winds involved extremely difficult,” BOM said.

“So we estimate wind speeds based on the amount of damage to trees, buildings and other structures built by humans.

“It is likely that tornado intensity will be underestimated in areas with low damage indicators, such as open fields or grasslands.”

This means that the majority of cyclones outside populated areas of Australia will go completely unnoticed or cannot be measured accurately.

“We can’t get a tornado report if there’s no one around to see it,” BOM said.

“They cannot be detected from satellite images because they are under the clouds.”

The United States, hit by an estimated 1,200 hurricanes each year, has different atmospheric conditions as well as a much larger human population to record and report them.

Tornadoes are measured using the Advanced Fujita scale, which ranges from EF0 (minor damage) to EF5 (incredible damage). It replaced the Fujita scale (F0 to F5) in 2007.

Australia has never recorded a tornado stronger than EF4.

However, America has been subject to several extremely destructive EF5 tornadoes, such as the Joplin tornado on May 24, 2011, which killed at least 116 people.

Tornadoes rated EF2 and above are called major tornadoes.

The strongest cyclones ever recorded in Australia

Although harder to track and record in Australia, many extremely powerful hurricanes have been confirmed since records began in the 1800s.

Hurricane Bucca — Queensland 1992

Hurricane Bucca made landfall in Bundaberg and The strongest recorded in Australia and the first and only local tornado officially rated F4 on the old scale.

On November 29, 1992, severe storms in the area soon turned into cricket ball-sized hail, forming a short-lived but devastating tornado around 3:30 p.m.

It is estimated that the hurricane destroyed nine houses and killed more than 20 cattle in its 10-minute lifetime.

Weather experts also recorded wind speeds of approximately 267 km/h to 322 km/h, with stones embedded in trees, tree saplings stuck in the walls of houses, and a 3-ton truck being thrown more than 300 meters away.

Cyclone Mulwala — NSW/Victoria 2013

A strong EF3 tornado was recorded at the NSW-Victorian border at Mulwala on 21 March 2013.

More than 20 people were injured, two seriously, and many houses and other structures were damaged or destroyed.

Wind speeds were recorded between 218 km/h and 266 km/h.

Balta Creek Hurricane — Victoria 2019

A powerful non-supercell occurred on June 29, 2019. Tornado formed in Ax Creekapproximately 12 km south-east of the regional Victorian town of Bendigo.

It almost completely destroyed one family’s double-brick home and carved a 750-metre-long path of damage through the property and nearby hardwood bushes.

Experts said the level of damage was consistent with an EF3 tornado.