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The Difference Between Hurricanes, Cyclones And Typhoons

Typhoon Hagibis is currently slamming into Japan, Hurricane Dorian devastated the Bahamas last month, and Cyclones Trevor and Veronica caused havoc Down Under in March.

All these weather systems left a trail of destruction, yet all had different titles.

Why?

Typhoons, hurricanes and cyclones are basically the same thing. All three form over warm tropical or subtropical waters where the sea's surface temperature is above 26 degrees. They use the warm, moist air as fuel.

The storms are typically hundreds of kilometres in diameter and pack strong winds and heavy rain that can lead to flooding and large, powerful surf.

Japan has just endured its worst Typhoon in decades. At least 35 people have been killed.. Image: Yohei Kanasashi via AAP

When a weather system reaches maximum sustained winds of at least 116 km/h it is classified as a hurricane, typhoon, or cyclone, depending on where the storm originates in the world.

Scientists often use tropical cyclone as the generic term.

But whatever they are called, tropical cyclones generally become weaker after they make landfall because they're no longer being fed by the energy of the warm ocean waters, according to the Bureau of Meteorology.

Which areas use which terms?

The term 'hurricane' is used in the North Atlantic Ocean and the northeast Pacific. The same weather event in the northwest Pacific Ocean is called a ‘typhoon’ and usually affects Asia.

Anything in the southern Indian Ocean or the South Pacific is known as a 'tropical cyclone'.

Those that form north of the equator spin counterclockwise, those in the south, clockwise.

Much like cyclones here in Australia, hurricanes are defined by a five-category system based on maximum sustained wind speed. Typhoons, however, are classified as "typhoon", "very strong typhoon", or "violent typhoon" by the Japan Meteorological Agency.

Destruction following Hurricane Dorian. Image: Twitter/Travis C-Carroll
Why and how are they named?

As soon a tropical cyclone is formed it's named, partly to provide ease of communication between forecasters and the public when it comes to watches and warnings, and partly to raise the profile of the cyclone to increase public awareness.

Because the storms can often last longer than a week, it's common for more than one to be clocked in any particular area at any one time. Naming them can, therefore, also reduce confusion.

READ MORE: Devastating Images Show 'Historic Tragedy' In Bahamas

There is a list of names that are arranged alphabetically and alternate between male and female. Each one needs to receive the final tick of approval from the World Meteorological Organization Regional Tropical Cyclone Committee before it is assigned.

If a tropical cyclone causes significant damage such as Cyclone Tracy or Cyclone Larry, the name is retired indefinitely. But if the storm dies down without damage, the name will be re-added to the bottom of the list and will be recycled in roughly a decade.

Super Typhoon Hagibis smashed into Japan over the weekend. Photo: NOAA Satellites via Twitter

In Australia, the convention began back in 1964. The first-ever cyclone named on the west coast was called Bessie. There are a lot of rules when it comes to naming -- you can read them and the full list from the Weather Bureau here.

READ MORE: In Pictures: Typhoon Hagibis Is Japan's Worst Storm In Decades

READ MORE: Cyclone Sandwich: State Of Emergency Declared In The NT

CYCLONE SEASON IS ON THE WAY FOR AUSTRALIA

The cyclone season in Australia is between November 1 and April 30. On average, there are between nine and 13 cyclones throughout the season, four of which typically cross the coast, the first in December.

This year there are expected to be fewer cyclones than normal, according to the Bureau of Meteorology.

According to the Tropical Cyclone Season Outlook released on Monday, it is because of the current state of Australia's climate drivers, particularly the neutral state of the El Nino-Southern Oscillation and a positive Indian Ocean Dipole.

Cyclone Trevor
Cyclone Trevor lashed the Northern Territory in March as Cyclone Beronica hurtled towards the Pilbara Image: Bureau of Meteorology

However,  the Bureau warns the risk is always high.

"We've never had a tropical cyclone season without at least one cyclone crossing the coast. This means that despite a reduced risk this season, all communities in northern Australia must be ready," Dr Andrew Watkins said.

"Even if cyclones stay well out to sea, they can still pose a significant risk to property and lives through strong winds, intense rain and flooding, and storm surges."

As intense and destructive as the storms can be, they help to regulate the global climate by moving heat energy towards the poles.