Improving Australia’s Tropical Cyclone forecasts

March 26, 2024

Climate Systems Hub researchers are working with the UK Met Office to evaluate global climate models used to predict tropical cyclones.

Tropical Cyclone (TC) Jasper was the first tropical cyclone in the Australian region for the 2023-2024 season.

It started as a tropical low east of the Solomon Islands and reached severe category 3 strength in the Coral Sea only 24 hours after formation.

Cyclone Jasper’s track and intensity. (Credit: Bureau of Meteorology)

According to the Bureau of Meteorology summary, TC Jasper crossed the far north tropical coast near the community of Wujal Wujal on 13 December with the region south of the centre extending to Port Douglas experiencing the strongest winds with wind gusts estimated to 130 km/h. But it was what ex-TC Jasper did over the next few days that had the biggest impact.

satellite image of a tropical cyclone

Credit: NASA Earth Observatory

Ex-TC Jasper then weakened and stalled over Cape York Peninsula for several days, dumping heavy rainfall over the north tropical coast area. This rainfall fell in river catchments already wet and produced widespread flooding in the region.

flooded road

After flood at Wujal. (Credit: Flickr/Ladymaggic)

Tropical cyclones are dramatic and devastating events. Planning for them is not only knowing when they will hit but predicting the wind speed, direction and amount of rain as the cyclones increase or decrease in intensity and move across the landscape.

Initial research underway by the Climate Systems Hub and the UK Met Office indicates that global climate models are getting better at predicting tropical cyclones.

As the climate changes, communities need to be able to plan not only their arrival but their impending force, direction and how much rain they will deliver.

Being able to accurately forecast tropical cyclone intensity, track and rainfall is key information for emergency management to limit the potential impacts to communities.

In Australia we use the Australian Community Climate and Earth System Simulator (ACCESS) models to forecast our weather and predict future climate. It is important that we continuously develop and evaluate these models and understand how well they perform for Australia.

Climate Systems Hub scientists from the Bureau of Meteorology are evaluating how well tropical cyclones are represented in models being considered for future operational weather prediction systems at the Bureau of Meteorology, and for use by the broader ACCESS community.

Results show that the models are improving in terms of tropical cyclone intensity, and a newly developed convection scheme, CoMorph, further improves tropical cyclone forecasts in terms of cyclone intensification, track and rainfall distribution. This work is being done in collaboration with the UK Met Office, contributing to the advancement of their future models and enhancing and benefiting our ACCESS model.

A key aim of this fundamental research is to improve Australia’s operational weather forecasts. It also influences decisions related to the choice of future operational models used by Bureau of Meteorology.

Andrew Burton, team leader for the Australian Tropical Cyclone Warning Centre at the Bureau of Meteorology’s Severe Weather Prediction Services, emphasises the importance of research emerging from the Climate Systems Hub.

“Research coming out of the Climate Systems Hub not only helps to improve the accuracy of the ACCESS suite of models, it also helps forecasters identify situations where models may exhibit systematic bias (in intensity forecasts for example),” he says.

“Knowledge of model biases enables forecasters to identify where they may be able to add skill by adjusting the raw outputs or placing greater weight on the predictions of one model over another.”

Back to News