Marine heatwaves can occur all year round as they are defined as conditions in the top 10% of the historical record for that location and time of year. 

El Niño events tend to peak in December and decay in the summer months, and can result in sustained, higher than usual ocean temperatures in certain regions around Australia, which can lead to marine heatwaves occurring. Some of the impacts might include mass coral bleaching, altered aquaculture yields, and changes in wild fish migration patterns. 

Physics-based atmosphere-ocean forecast models have increased in resolution and accuracy, as has our understanding of how these events develop and persist. There are ocean observing facilities that target marine heatwaves and other extreme events which can further this understanding and provide rich datasets for verification of forecasts. Machine learning techniques also have great potential to produce useful marine heatwave forecasts directly or to assist with calibration and downscaling of seasonal prediction model output.

The marine heatwave forecasting that we are now able to do is truly cutting edge. 

Since the last El Niño in 2015-16, we’ve learned a lot and we’re now in the unique position of being able to provide forecasting on two- or three-month timescales. That advance warning gives stakeholders a lot more time to prepare and hopefully mitigate some of the risks of MHWs. 

The forecasting we can now do means that we take away some of your ability to be surprised. Having access to that information so far in advance means there’s a whole spectrum of things that can be done – starting when the risk is likely but not certain, and moving all the way through to when the risk is emerging. 

Australia’s efforts around identifying bushfire risks - preparing for those events and planning for the recovery stage – have improved greatly in recent years. Now we need to see the same level of co-ordination around extreme events in the ocean.  With more information available, we have the opportunity to provide much better support for our marine industries and the blue economy.