European Windstorm Risk Of Post-Tropical Cyclones And The Impact Of Climate Change

Sainsbury et al. (2020, https://doi.org/10.1029/2020GL089853) highlighted the fact that although post-tropical cyclones only consist of a small part of the cyclones impacting Northern Europe (similar to 1%) during the hurricane season, their contribution to storms with at least storm force (>25 m/s) is about 10 times larger and therefore pose a substantial windstorm risk for Northern Europe. Overall postTCs impacting Northern Europe are significantly more intense than midlatitude cyclones. This is related to their combined tropical (warm seawater) and midlatitude (baroclinic instability) energy source. A few studies have suggested that in a warmer climate the amount and intensity of post-tropical cyclones might increase due to stronger tropical cyclones (TCs), warmer oceans, and pole and eastward extension of TC genesis regions. This would further enhance the windstorm risk of post-TCs. Further high-resolution modeling research is required to delineate this risk.Plain Language Summary In the analyses of European windstorm risk, generally only winter storms that develop over the North Atlantic are considered. However, Sainsbury et al. (2020, https://doi. org/10.1029/2020GL089853) made clear that remnants of tropical cyclones (TCs) (hurricanes over the Atlantic), although being only a small fraction (similar to 1%) of the total storms reaching Europe during the hurricane season, need also to be taken into consideration. In terms of severe wind storms their fraction is about 10-fold (similar to 10%). Their average strength is also larger than that of other storms. A few studies have suggested that the amount and intensity of those remnants of TCs that reach Europe might increase due to climate change, thereby further increasing their windstorm risk. Further research with climate models is required to further investigate the potentially high windstorm risk for Europe in the future of those remnants of TCs.