We thank Andrew Dowdy, Charlie Lok, Chis Landsea, and two anonymous reviewers for their valuable insight. We acknowledge the Pacific Australia Climate Change Science and Adaptation Planning program (PACCSAP) project for supporting this work. PACCSAP is funded by AusAID, in collaboration with the Australian Government Department of Climate Change and Energy Efficiency, and delivered by the Australian Bureau of Meteorology and the Commonwealth Scientific and Industrial Research Organisation (CSIRO).
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The OWZP method was developed using data spaced 24 h apart. For valid comparison, the observed data used were also 24 h apart. In this paper we continue to use model data at 24 h intervals, despite CMIP5 data being available at 6-hourly intervals. This decision was made for two reasons: (i) to reduce the very considerable processing time and (ii) to avoid revalidation of the OWZP technique at the higher time frequency. We note that the OWZP is being run in real time at 12-hourly intervals with very promising results, but the results are yet to be objectively verified.
The SH950 threshold of 12.3 g kg−1 [used in Tory et al. (2013a,b)] had been lowered from a preliminary value of about 15.0 g kg−1 in order to increase the number of detections of observed TCs in the North Atlantic that we now classify as subtropical. The 12.3 g kg−1 value was the best compromise between detecting as many observed North Atlantic TCs as possible while minimizing the number of false detections at higher latitudes in all basins.