Aussies are being warned to stay alert this summer with an increased risk of tropical cyclones expected to hit the Queenland coast, thanks to warmer sea temperatures caused by the La Nina weather system.
The Coral Sea, off the northeast coast of Australia, had its warmest spring on record, Weatherzone reported on Wednesday, with current temperatures sitting above 28 degrees.
Alarmingly, the rise in sea temperatures means there's a 74 per cent increased chance of cyclones in the eastern region between now and early autumn, the Bureau of Meteorology has forecast, and people should "be prepared", Weatherzone meteorologist James Rout told Yahoo News Australia.
Warmer water is "one of the key ingredients for tropical cyclones," he said. "For tropical cyclones, you need temperatures of the water to be at least above 27 degrees so we’re seeing that in the Coral Sea," he explained.
According to Weatherzone, the sea surface temperature in the Coral Sea during spring was +1.15ºC warmer than the 1961 to 1990 average, making this its first spring with an anomaly above 1ºC. The previous warmest spring in the Coral Sea was in 2016, which had an anomaly of +0.88ºC compared to the long-term average.
Higher risk of cyclones hitting land
The average number of cyclones detected off the Aussie coast is four a year, but this year more are expected. What's more, La Nina means there's more chance of one hitting land this year, compared to La Nino events where most stay out at sea, Mr Rout explained.
"Tropical cyclones are the most destructive type of weather, but thanks to modern technology, we can forecast them fairly accurately with good lead time," he said. "The most important thing [for people to do] is to stay up to date with the warnings and the forecasts."
Heightened beach safety this summer
Mr Rout also warned about rougher seas and stronger waves, warning "some of the most destructive aspects of the cyclone is the waves".
"It's called storm surge," he explained, which is when the cyclone pushes the ocean up against the land "like a tsunami". "That's the most destructive part," he added.
The expected weather conditions pose an additional risk for those swimming in the ocean this summer as rougher seas might be experienced, Mr Rout said — but that depends on the tide.
"If it’s high tide and the cyclone is pushing the water, then the wave will be very destructive. If it’s low tide it’ll be less of an issue," he said. Mr Rout said swimmers have to be "very careful of waves, even if the cyclone is off the coast and not on land". "It can still bring in some large waves," he added.
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