Jonathan Brown with Centre researchers.

A groundbreaking new study has found rapid rain bursts have intensified over Sydney by 40% in the last 2 decades.

The findings have major implications for Sydney’s preparedness for flash flooding and associated impacts in the future.

“Sydney has seen rapid rain bursts intensify at an alarming rate in the last two decades” says Dr Hooman Ayat, Research Fellow at the ARC Centre of Excellence for Climate Extremes.

“Our study utilises a new technique to give us more information on these rapid rain bursts than was previously possible. Using weather radar data, we identified thousands of rapid rain bursts in Sydney over two decades and saw a 40% increase in intensity. What’s particularly concerning is that we weren’t able to identify usual climate variability as driving this change, so climate change may be a factor in this shocking result”

Dr Hooman Ayat, Professor Steven Sherwood and Professor Jason Evans.

The study has major implications for Sydney and potentially cities all over the world.

“If this trend continues in Sydney, the city needs to be more prepared for rapid rain bursts and flash flooding into the future” says Professor Jason Evans, Chief Investigator at the ARC Centre of Excellence for Climate Extremes.

“This should factor into our city planning with buildings, roads and communities needing to prepare for the likelihood of more rapid rain bursts to test the short term capacity of our drainage, roads and flood plains” says Evans.

Professor Steven Sherwood and Dr Hooman Ayat

The study uses a groundbreaking new technique that uses weather radar data, rather than rain gauges, satellite data and climate models, which to this point have struggled to accurately  identifying rainfall on such short timeframes.

“We’ve been able to use this technique to gain insights into a possible extreme rain future for Sydney, but we think this technique can also help other cities assess recent trends and prepare for the future.” says Professor Steven Sherwood, Chief Investigator at the ARC Centre of Excellence for Climate Extremes.

“If what we saw over Sydney is occurring in other cities around the world, governments, councils, city planners and communities need to prepare for the possibility that rapid rain bursts will get more and more extreme. This is a concerning new phenomenon that needs more research.”

The research has been published in the prestigious Science journal: 10.1126/science.abn8657