“We’ve had threeLa Nina years in a row,which is quite rare,and what it means is the soils are already soaked. When it rains,there’s really nowhere left for the water to go. The rivers are already full,so the water moves along the surface.”
Like the bushfires of 2019-20,when droughts had primed the landscape to burn,now the state is primed to flood,said Professor Jason Evans of the Climate Change Research Centre at the University of NSW.
“It’s a very unusual year – you don’t have to look very far in terms of rainfall records to see records being broken,” he said.
“One of the things that’s making this really unusual is that we’re seeing extreme rainfall events in many different places in the same year,as well as repeated events in some places,such as northern NSW. Now that the ground is well and truly soaked it’s primed for flooding.”
TERN mapping system
When a series of low-pressure weather systems formed off Australia’s south-east coast last month,sucking up moisture from the Tasman Sea and carrying it over the land,rain fell on many districts that had already soaked up as much water as the ground could handle.