Counterfactual Analyses of European Windstorms with the CoreLogic® Eurowind™ Model
The intention of this white paper is to better understand European windstorm risk using CoreLogic’s European Windstorm Model (Eurowind™) and a style of analysis known as “counterfactual analysis” to understand how small changes in storm parameters or meteorological conditions could have resulted in monumental loss changes, relative to what occurred in history.
European windstorm is regarded as a peak peril. Nevertheless, its contribution to total insured losses has decreased over recent decades (Figure 1), and there is some expectation in the industry that losses are set to remain relatively low.
Figure 1: Share of insured losses by decade. Source: Swiss Re Institute, 2023
The decreased contribution to decadal insured losses by European windstorm raises important questions: is this reduction driven by a climate change or is it a consequence of climate’s natural variability and therefore, should we expect losses to increase once again soon?
This white paper uses three counterfactual approaches to answer these questions. A counterfactual analysis answers the question of “what-if?” assuming input data different from what actually occurred.
The first two analyses use CoreLogic’s Eurowind™ Model. The third and final approach draws upon one of the input data sets used to build Eurowind™: a synthetic storm footprint catalogue created in partnership with the School of Geography, Earth and Environmental Sciences at the University of Birmingham, which is available exclusively to CoreLogic.
The results of the studies in this report indicate that losses of recent history could have been higher under altered weather conditions and that the threat of an imminent significant European event remains.