On the connection between the jet stream and high-impact, extreme storms in midlatitudes

Extreme storms are a major natural hazard in the extratropics. These storms can cause substantial economic damage due to strong winds and flooding, interrupt transportation networks and electricity supply and lead to casualties. Future climate projections predict an extension of the storm track further into Europe posing a potential for increased risk with climate change, especially in winter. However, despite its importance, the connection between extreme, high-impact extratropical storms in midlatitudes and changes in the jet stream remains uncertain. 

Using reanalysis data and multi-model ensemble of climate models under future socio-economic scenarios, we examine the variability of extreme and high-impact storms in the northern hemisphere midlatitude and investigate the connection between jet stream intensity and extreme storm impacts. For this purpose, extreme storm events are diagnosed using the wind field (defined as spatially organized clusters exceeding the 98th percentiles of wind speeds over a specific area for a specific duration). High-impact storms, on the other hand, are identified according to the Emergency Events Database, a global database on natural and technological disasters, for the period 1998 to 2023. This comparison provides insights on extreme storm damage variability in midlatitudes and allows us to explore regional differences in storm damage and future changes. Understanding and connecting the dynamical processes controlling the variability of the jet stream and extreme, high-impact storms in midlatitudes is essential for skillful prediction of these extreme hazards under climate change and for assessing their potentially devastating impacts.