Tasmanian wind and rain event one of Australia’s Climate Extremes in 2023

A weather event in Tasmania was so wild it made the nation’s top 10 extreme climate events for 2023 — ranking alongside cyclones and flooding. Why it stood out.

Professor Andy Pitman, leading climate change scientist, pictured in Sydney, is leaving Macquarie University to help form the biggest university-based climate research group in Australia at the University of New South Wales (UNSW).

A rain and wind compound event in Tasmania is one of Australia’s climate extremes of last year, a new report has found.

More than 30 Australia’s leading climate scientists collaborated on the Australia Research Centre (ARC) Centre of Excellence 2023 Climate Extremes Report, designed to help the public and decision makers understand the complexity of climate extremes.

Among the list includes Cyclone Ellie and Jasper, extreme rain in Queensland and Northern Territory and a compounded rain-wind event in Hobart.

It started with a slow-moving low-pressure system which intensified and brought heavy rains and a thunderstorm across the state, recording more than 40,000 lightning strikes on October 21 and 22.

A subsequent system developed and brought strong winds of nearly 100km/h in Hobart and 159km/h on kunanyi/Mt Wellington caused damage to the area a few days later.

Bureau of Meteorology rain radio of Hobart Oct 21, 2023.

Hobart Tasmania Weather Update on Sunday 22nd October 2023. Assistant Director of Operations with SES, Leon Smith talks to media about the weather event on Saturday evening. Picture: Linda Higginson

While winds of that speed aren’t uncommon for Tasmania, the effect of the gusts and the system which brought heavy rain and saturated the soil, was compounded.

When saturated by rain, tree roots are not held firmly in place by soil, leading to trees failing easily.

If just one of the systems occurred without the other, the widespread damage that resulted from falling trees and power outages would have been reduced.

ARC researchers found extreme wind and rain compound events wold occur more in regions across the country in the future if greenhouse gas emissions were not reduced.

“What was unusual about 2023 is how intense some of these events were and how they kept pushing records,” ARC Centre of Excellence for Climate Extremes director Professor Andy Pitman said.

Professor Andy Pitman, leading climate change scientist, pictured in Sydney, is leaving Macquarie University to help form the biggest university-based climate research group in Australia at the University of New South Wales (UNSW).

“There’s plenty of places around the world where events are becoming hard to survive.

“What scientists bring to the table is more and more evidence of what we already know. We need to act based upon observations and existing knowledge.

“The actions are straightforward: stop emitting carbon and invest heavily in adaptation.”

The report also showed there is an increasing trend of the hottest day of each year from 1910-2022, with strong warming over parts of Tasmania and Northern Australia.

The report said anthropogenic emissions of greenhouse gases have caused increases in temperature extremes across the country.

Originally published as Tasmanian wind and rain event one of Australia’s Climate Extremes in 2023