Weather bureau expects extreme heatwave across northern Western Australia and Top End in next week, with severe conditions in NSW, Queensland and South Australia
Last modified on Tue 14 Dec 2021 18.34 EST
Australia will have a summer of extreme weather as heatwave conditions settle in much of the country over the next week while storms on the east coast may mean more floods in coming months.
The Bureau of Meteorology has forecast an extreme heatwave across northern Western Australia and the Top End in the next week, with severe conditions in Queensland and parts of New South Wales and South Australia.
Capital cities on the east coast will escape the worst of it through the week before getting hotter on the weekend.
Melbourne is expected to stay in the 20s for the rest of the week before rising to 35C over the weekend. Going into Saturday, Brisbane, Sydney and Canberra are forecast to brush 30C, while temperatures are expected to spike to 37C on Friday in Adelaide.
With a heat dome forming over the centre of the continent, those inland are likely to experience even higher temperatures.
Dubbo is expected to reach 38C by next Saturday, while Broken Hill is forecast to reach 40C. In the Northern Territory, Katherine is predicted to hover around 41C for most of the week, with Alice Springs to reach 42C on Friday.
Temperatures may be pleasant in Perth, which is not expected to reach 30C this week, but Port Hedland in the Pilbara is predicted to hover at 40C all week before climbing as high as 45C on Sunday.
As the mercury climbs in regional areas, La Niña is expected to bring storms to the south-east in Canberra and parts of regional Victoria and New South Wales.
These are expected to continue through a hot, wet summer as scientists warn the ongoing flood risk means there is a “pretty high” chance dams and catchments may overflow under heavy rain.
Dr Ashish Sharma from UNSW’s School of Civil and Environmental Engineering said climate change was making floods less common on average but rainfall was more intense when it arrives.
Under normal conditions or following periods of drought, floods are unlikely to form. But in the wet conditions brought by La Niña the soil is already soaked, meaning rainfall has a 68% chance to form a flood.
“Big rainfalls are coming down but because La Niña is creating wetter ground conditions, they are creating bigger and bigger floods,” Sharma said.
Sharma said with dams and catchments already at capacity there was a risk they would make flooding worse.
“Since our dams are in the roughly 90% mark across much of the east coast, the possibility of spills is pretty high,” Sharma said. “Dam spills add to river flow so they compound the flood risks downstream.”
While Sharma said there was little to be done in the short term, on Tuesday the New South Wales government released a new planning guide to help local councils prepare for natural disasters caused by climate change.
The minister for planning and public spaces, Rob Stokes, said the plan would encourage councils to consider the risk posed by natural disasters early in the planning process.
“The impacts of climate change are already being felt in Australia with fire, drought and floods having devastating impacts on people, homes and businesses,” Stokes said.
“This new guide will help make sure NSW homes and businesses are built in the right places, to help protect against the destruction of natural disasters.
Dr Amy Peden from UNSW’s Beach Safety Research Group said events such as La Niña also bring an increased risk of drowning with 294 people died in the last year – an increase on the average of 273 people.
The majority of these deaths occur in rivers, with half involving people who attempted to drive across rivers and become trapped.
Six people have died since the La Niña event was declared.
“The six drowning deaths we have all seen so far has involved driving into floodwaters, but the others we see are playing in floodwaters,” Peden said.
