A reputable study was published in September this year which raises some concerns for communities in Northern NSW.
"Using large climate model ensembles to assess historical and future tropical cyclone activity along the Australian east coast" [Bruy`ere, C.L. et al, Sept 2022] is a collaborative effort supported by the National Center for Atmospheric Research (USA), Insurance Australia Group Limited (Aust), Cyclone Testing Station, James Cook University (Aust) and Environmental Sciences and Management, North-West University (South Africa).
The message bottom line is that Australian East Coast Tropical Cyclones (TCs) are now anticipated to extend their range into south-east Queensland and on into Northern NSW as far south as the Clarence Valley and possibly Coffs Harbour City local government area.
At the same time the frequency of strong tropical storms and cyclones are expected to increase, their heavy rainfall areas to widen, intensify and in some instances their wind fields to remain over locations for longer periods.
The following is an excerpt from the Introduction to the aforementioned study.
"Building codes can be highly effective at reducing TC losses (Done et al., 2018). They are commonly designed to safeguard people from injury caused by structural failures (e.g., the Australian Wind Loading Standards - ASNZS1170.2).......
A collection of recent work demonstrates that Australian TC statistics are non-stationary. Holland and Bruyère (2014) detected an increasing proportion of the strongest storms. Kossin et al. (2020) found that the absolute numbers of intense storms have increased. Not only are the peak wind speeds increasing, but the latitudes of storm-lifetime peak winds have likely shifted poleward in this region (Kossin et al., 2014). Cyclone forward motion has also slowed down over Australia (Kossin, 2018), meaning that locations experience strong winds for longer, all other things being equal.
TC rainfall is also changing. Studies show heavier TC rain rates in some regions (e.g., Risser and Wehner 2017; Emanuel 2017). Bruyère et al. (2019) showed that when changes in thermodynamical conditions alone are considered (i.e., thermodynamic climate change scenarios), TCs penetrated much further inland with a marked expansion of the heavy rainfall area. Should these wind and rainfall trends continue (as indicated by Knutson et al., 2020; Walsh et al., 2016a; Lavender and Walsh 2011), this raises the prospect that current wind loading codes and flood planning zones may not protect people and property as well as they have in the past and may severely underperform in the future.
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