Three cyclones may form, converge off north Australian coastline

Three tropical cyclones are expected to converge off the north coast of Australia at the weekend, with climate experts predicting a rare clash of systems that could lead to dangerous weather.

THREE tropical cyclones are expected to converge off the north coast of Australia at the weekend, with climate experts predicting a rare clash of systems that could lead to dangerous weather.

Tropical Cyclone Seroja, the system that wreaked havoc across East Timor this week, will close in on two other tropical systems — one of which has now formed into Tropical Cyclone Odette — brewing in the Indian Ocean.

The rare and potentially dramatic convergence of systems known as the Fujiwhara Effect is likely to lead to a brief but intense window of wild weather along much of the West Australian coast.

People on WA's coast should prepare for intense wind, rain & possible flash flooding over the weekend & Monday. The first impacts to WA are expected Sat night around Exmouth. Late Sun/Mon TC Seroja is expected to cross coast between Carnarvon & Jurien Bay https://t.co/XHYXuHrieCpic.twitter.com/noukmT1XpK

— Bureau of Meteorology, Western Australia (@BOM_WA) April 8, 2021

Locals and residents along a 1000km stretch of coast have been advised to “prepare now” as tropical cyclones Seroja and Odette edge closer to land.

Wind gusts of up to 150 km/h could push inland and rain will come “hard and fast,” the Bureau of Meteorology (BoM) has warned.

Seroja could be the most southerly cyclone to make landfall in two decades. That could lead to hectic weather associated with the system as far south as Perth.

“Now is the time to prepare as the impact from these cyclones will be felt in the next 24 to 28 hours, “ said BoM meteorologist Jonathan How on Friday.

Three powerful systems are developing at the same time. Picture: Supplied

RELATED: Rare Fujiwhara effect weather phenomenon could hit coastline

Another tropical low is also looming near the Cocos Islands.

Tourists holidaying in Western Australia’s north have been warned to leave the area as the storm systems converge.

BoM senior meteorologist James Ashley said three powerful systems developing at the same time was “extremely uncommon”.

“I’ve been working here in Perth for over 20 years and I’ve never seen us have three systems so close to being cyclones or being cyclones at the one time,” he said.

“Generally, cyclones tend to need a bit of space between them so they don’t mess each other’s inflow and winds and moisture feeds and things like that.”

Rare Fujiwhara Effect could turbo charge cyclone

Tropical cyclone Seroja, currently a category 1 system, is sitting more than 500kms northwest of Exmouth and 760km northwest of Carnarvon, but is gradually shifting southwest.

Tropical cyclone Odette, also at category 1, is moving south east from a position 940 km northwest of Exmouth and 620 km south east of Christmas Island.

The pair are expected to begin interacting with one another on Saturday in what is knows as the Fujiwhara Effect.

“This rare meteorological phenomenon is taking place with Seroja and Odette engaging in a bit of a rotating dance where cyclones orbit one another,” said Sky News Weather meteorologist Alison Osborne.

Tropical Cyclone Seroja is heading towards the WA coast

Seroja, the stronger of the two, is likely to build up its power at the expense of Odette that could weaken to a tropical low.

Nonetheless, Odette could still pack a punch during its brief life bringing gale force winds and rain to Exmouth on Saturday afternoon.

Tropical Cyclone Seroja is expected to cross the coast as a Category 2 system late on Sunday or early Monday.

“Seroja is expected to bring dangerous weather conditions to the west coast during Sunday or Monday … this is a rare event for people on the west coast of Western Australia with potential impacts in the area between Coral Bay and Jurien Bay, including Carnarvon, Denham, Kalbarri and Geraldton,” the Bureau said.

RELATED: ‘Extraordinary’ conditions as polar air hits southern states

Tropical Cyclone Seroja expected to bring dangerous weather conditions to the west coast during Sunday or Monday.The track map shows #CycloneSeroja intensifying to category 3 on Saturday and reaching the coast as a category 2 system late Sunday or Monday. https://t.co/B1MVXBYXhhpic.twitter.com/v2D5slFCij

— Bureau of Meteorology, Western Australia (@BOM_WA) April 9, 2021

Perth warning: Cyclone could be most southerly in more than two decades

It is almost unheard of for cyclones to make landfall south of Carnarvon with the last such event in 1999. Cyclones need warm water for fuel and the further south these systems go, the cooler the water gets.

“Winds this strong are rarely felt this far south. While most winds will be roughly equivalent to the strongest winds experienced in an intense winter storm in the south west there is a chance that near the coast winds may be slightly stronger,” the BoM stated.

“Heavy rain is expected to fall hard and fast at rates typically only having 10 per cent to 2 per cent chance of occurring in a year.”

RELATED: Australia’s autumn weather outlook – wet conditions sent to linger until May

🗣️Attention parents! What are you doing for the school holidays? Campers ⛺ pack tent pegs as central Australia will be windy this weekend. In the north, it will be quite warm so stay cool with a dip. Check Bureau's weather app for weekend forecasts https://t.co/m1aRm1Hec9pic.twitter.com/rF4gJ4RgRR

— Bureau of Meteorology, Northern Territory (@BOM_NT) April 9, 2021

Mixed weather bag for the Territory this weekend

Heading out and about for the first weekend of the school holidays?

The BoM says to expect a mixed weather bag with warm to hot temperatures for northern NT and cooler conditions for southern parts of the Territory.

While it was warm to hot in central areas on Friday, a cooler change will be pushing through the southern border overnight bringing cooler conditions for the south on Saturday, extending to Tennant Creek on Sunday.

A windy southeasterly change will have the potential for raised dust. With the windy conditions, a reminder to not forget to take your tent pegs if you have plan to camp in central Australia this weekend!

If you’re planning to head to the coast, expect humid conditions for coastal areas with the potential for a few showers and the odd thunderstorm. Isolated coastal thunderstorms are likely to bring gusty winds.

For those heading out on the waters, lady luck is smiling at you this weekend. Winds will be on the lighter side, generally about 10 knots, increasing to 10-15 knots over west coastal waters. Inshore sea breezes will get to 10-15 knots in the afternoon.

For all NT forecasts, check the BoM website.