We’ve been hearing about La Nina and the devastation heavy rain has caused in Australia. Flooding in the suburbs near rivers and low-lying areas of New South Wales have been damaging. 

Sydney was hit hard with rain in the late months of 2022. Are there any signs of these major weather events calming down for 2023?

What is La Nina?

Influenced by the interactions between the ocean and atmosphere of the Earth, a weather spectrum called the El Nino-Southern Oscillation (ENSO) occurs. It has three phases: El Nino, La Nina and neutral. This is a complex cycle lasts between one to eight years. 

Put simply, these phases are indicated by the coolness or warmth of the Pacific Ocean.

La Nina are often associated with a cooler Australian climate with much more rainfall. El Nino are often associate with heat and drought in eastern Australia areas.

What is the history of New South Wales weather events?

Because the ENSO greatly impacts the Pacific Ocean, the east coast of New South Wales can be hit hard by extreme weather.

This is our third La Nina in a row in three years, and this is the fourth time it has happened since 1900. 

"I've lived in Sydney for decades and seen two extended La Nina events, but this one has been the most devastating I've experienced.  As a plumber, the damage done to Sydney homes have been unprecedented, let alone what we've seen in places like Lismore," said Joe Rantino, a plumber working Sydney’s North Ryde catchment.

La Nina can be especially devasting to older suburbs of Sydney due to old plumbing systems that can’t handle extreme amount of water.

While this weather phenomenon is rare, does it seem to be getting worse?

What is different about the current weather events?

Climate change is a likely driving force in how El Ninos and La Ninas act today and in the future. With more emissions, the oceans are warming.

Warmer temperatures in the Pacific Ocean will lead to stronger El Ninos, which means hotter and drier conditions. Strong El Nino events often cause stronger and longer La Nina phases as a result of the extreme heat.

As we can see from the past, La Ninas are getting wetter and becoming more prolonged. With record-setting rainfall in the last few months, people are getting understandably worried for the future.

What are the predictions for the future?

Climate change has made weather a little more volatile, but are there any signs to things settling down?

While it is still too early to tell, four La Nina events in a row has never happened and is unlikely to occur. We won’t know if there will be another La Nina until the months between February and May, where more accurate predictions can be made.

Learn more about ENSO and the Australian climate on the Bureau of Meteorology website.

How can we prepare?

When it comes to protecting your home, you need to make sure that water can flow somewhere. Check and clear your drains, gutters and pipes. Your local plumber can help you prepare your home and upgrade your plumbing and drainage to deal with unexpected weather.