Australians have been told to be prepared for wild weather, a La Nia that brings heavy rainfall, intense storms and major cyclones.
Australians are being warned of more storm damage in the coming months as the La Nia weather event begins.
Last summer was hit by major climate drivers, but weather experts fear the country could be forced to battle heavy rainfall, more intense storm systems, larger cyclones and severe flooding this season.
Former fire chief Greg Mullins told a Climate Council briefing on Friday that there was “great concern” among emergency management personnel about this summer’s La Nia weather event.
“The problem at the moment is the frequency of events and the amount of precipitation,” he said.
“We are now in a situation where, particularly in Queensland and New South Wales, the catchment and soil cannot take up as much moisture.
“Any more rain just pours over the top, fills creeks, rivers, dams, and they gain capacity and then you get a river flood.”
Mr. Mullins feared that the extra-moist soil would cause large trees to fall.
“That wet soil doesn’t know how to read big trees…the big crowns of trees are like sails and blown in the wind and the roots keep them there but if the soil is too moist the trees die, ” He said.
“It will cause huge damage in any type of thunderstorm so we are pushing for it.”
The Weather Bureau issued a La Nia “watch” on 14 September, which was later changed to a La Nia “alert” on 12 October – then the event was confirmed on 23 November.
Much of eastern Australia has already been swept by heavy rain and thunderstorms that flooded the Lachlan River catchment in the NSW central west last month.
On Thursday, Melbourne’s CBD was temporarily plunged into darkness as storm clouds rolled across the city and heavy rain lashed the eastern suburbs.
That night, on the second day of summer, thousands of homes spent hours off the grid.
The La Nia weather phenomenon, associated with the transfer pattern of sea surface temperature through the Pacific and Indian Oceans, affects precipitation and temperature variation in Australia.
It is generally associated with heavy rainfall in the eastern, northern and central parts of the country as well as a high probability of tropical cyclones.
Mr. Mullins anticipates stronger cyclone systems during this La Nia event.
“There are probably fewer cyclones under a warmer climate, but when they do come they’re going to be doozy,” he said.
“They’re not going to be category two and three, they’re going to be category four and five and you know, there’s also talk about adding a category around the world because they’re on the scale so far in the Northern Hemisphere. Huh. “
Dr Simon Bradshaw, the Climate Council’s head of research, said this season’s La Nia weather event was already underway in “dramatic terms”.
He warned of more intense rain, coastal flooding and erosion, and a higher-than-average number of cyclones crossing the coast.
Dr Bradshaw also warned of a longer summer in southern states, but some will be “more humid” and “not as intense”.
“We are seeing risks similar to what we might normally expect, although certainly elevated in some areas,” he said.
The Meteorological Bureau says that this La Nia event is likely to continue until at least the end of January 2022.