The Bureau of Meteorology is warning residents in northern Australia to be on alert for a greater possibility of cyclones developing and potential flooding in coming months, as the region enters its third La Niña wet season in a row.
The northern wet season officially began on Saturday and while it normally begins with a slow and steamy build-up, forecasts are showing more rain is on the way this week.
Last month the Bureau of Meteorology declared a La Niña in the Pacific Ocean, meaning much of the country can expect a rainy end to 2022.
“We have already seen that with some storms coming through across the Top End in the last week,” the weather bureau’s NT hazard preparedness and response manager Shenagh Gamble said.
“[La Niña], combined with the ongoing Indian Ocean Dipole, which has been affecting the Northern Territory since about June this year, definitely contributes to a warmer and wetter build-up period here.”
La Niña doesn’t just bring rain. Ms Gamble said that both the IOD and La Niña are also “associated with a higher number of tropical cyclones across the Australian region”.
“But it is not associated with the intensity of tropical cyclones.”
The BOM will launch its 2022–23 cyclone outlook next week, ahead of the start of the official cyclone season which runs from 1 November to 30 April.
In the outlook, the bureau is expected to provide an estimate for how many cyclones it believes could impact the Australian region in coming months.
Farmers brace for flooding
While cyclones are likely to get plenty of attention this year, Ms Gamble said a third La Niña in a row also brings a greater risk of flooding.
So-called “triple-dip La Niñas” are not unprecedented, but according to the bureau they have only occurred four times since 1900, including now.
And they typically coincide with major flooding events.
“Each year we’re experiencing higher than average rainfall and over the drier periods it doesn’t get as much time to dry out, so that is probably the risk that is enhanced with back-to-back La Niña events,” she said.
Last year supermarket shelves in Alice Springs and Darwin were left largely bare and cafes struggled to find fresh produce after vital transport links, including the Stuart Highway and the Adelaide to Darwin rail line, were cut by floodwaters.
NT Farmers spokesman Iain Forrest said that while rainfall benefitted producers, the organisation held concerns about whether more flooding could affect the export of crops interstate.
“We’ve got the mango season happening right now and if roads are cut, that’s potentially a huge amount of income lost for mango producers,” he said.
“It is a concern.”
Mr Forrest said the early arrival of rains this year could delay the ongoing mango harvest and upcoming planting of melon crops in the Northern Territory.
Stingers return to our shores
With the start of the wet season comes the start of stinger season, as heightened water temperatures bring more box jellyfish to the coastal waters.
Surf Life Saving NT chief executive Samantha Farrow said box jellyfish stings can have potentially deadly consequences.
“It can be from having a red welt show up for one to two weeks, to hospitalisation, to even potentially passing away,” she said.
“Our advice at the moment is just to stay out of the water for the next few months … through the wet season, it’s just too risky to be in there.”
She said surfers who brave the monsoonal swell are also at risk of being stung.
“The theory that some people operate under is because the water is so rough the jellyfish have moved out to sea, and that’s not always the case,” Ms Farrow said.
“The tentacles can break off and even if they’re a loose tentacle they can still sting you.”
