More rain on the way

A CLIMATE expert has warned that a forecast third consecutive La Nina could bring a repeat of the heavy rainfall that devastated parts of the Darling Downs and Lockyer Valley earlier this year.

The warning comes as Toowoomba records the wettest start to a year since the early 1990s, with more than a year’s worth of rain falling in just six months.

University of Southern Queensland climate scientist Professor Roger Stone said the drenchings had been a result of a La Nina climate driver, delivering wetter-than-average conditions across much of the country the past two years.

Professor Stone said UniSQ modelling suggested that a third consecutive La Nina could be on the cards this spring and summer, drenching already soaked landscapes, increasing the likelihood of more flooding.

“The forecasts are pretty well unanimous that there will be above average rainfall over the new year and into 2023, which will be a repeat of what we’ve been having the past couple of years,” he said.

“The risk of flooding is always there with a La Nina, it’s the period of highest risk. While we have a La Nina the risk of flooding is always there.

“As we get closer to summer we will monitor to see if the situation gets more intense, but from this early stage there is an increased risk of flooding with this sort of pattern.”

Professor Stone said it was rare to see three consecutive La Nina weather systems.

“It happens about four times a century, it’s not impossible but it doesn’t happen often,” he said.

“The best examples are in the 1970s from 1973 to 1975, as well as what we saw in 2011, 2012 and 2013.

“This will be our wettest period from autumn to autumn.”

The latest Bureau of Meteorology Climate Driver Update indicates there is a 50 per cent chance of La Nina forming later in 2022, about double the normal likelihood.

“La Nina events increase the chance of above average winter – spring rainfall across much of northern and eastern Australia,” the statement said.

“All climate model outlooks surveyed indicate a negative Indian Ocean Dipole event is likely for the coming months. A negative IOD increases the chances of above average winter – spring rainfall for much of Australia.

“Sea surface temperatures are currently warmer than average around much of the Australian coastline.”