Every few years major tropical cyclone events extensively damage Australian communities and businesses with billions of dollars of insured and uninsured losses, coupled with significant infrastructure damage and social trauma. However, tropical cyclone impacts for any particular location are infrequent and so knowing the true risk faced by individual communities around the tropical coastline is a growing challenge to general insurers such as the Insurance Australia Group (IAG).

With a rapidly changing climate there are emerging signs that the historical climate of tropical cyclones may not be enough to define tropical cyclone risk looking forward. This leads to a collaboration project between IAG and NCAR C3WE to analyse the modelled tropical cyclones across eastern Australia using NCAR's Community Earth System Model (CESM) Decadal Prediction Large Ensemble (DPLE) dataset which comprises sixty-four distinct ensembles for initiation times each year between 1954 and 2017, with 40 model members per year running out a decade ahead. This provides over twenty-five thousand years of model data spanning past, current and near-future climates.

This project aims to identify persistent environments for tropical cyclone formation and intensification.

The DPLE dataset resolution is 1 degree. In phase 2, key tropical cyclones from the ensemble will be downscaled using NCAR's Hybrid Cyclone Model (HWCM). These targeted higher resolution runs will detail changing structures of tropical cyclones during coastal crossings.

 This project will highlight natural variability in the tropical cyclone climate for the east coast of Australia, as well as better defining the historical and near future spatial risks of tropical cyclone coastal impacts. The data will be analysed for signs of climate change related trends, including the projections spanning the coming decade.