- 1Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland (anamaria.vicedo@unibe.ch)
- 2Oeschger Center for Climate Change research, University of Bern, Bern, Switzerland (anamaria.vicedo@unibe.ch)
- 3Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland (samuel.luethi@usys.ethz.ch)
- 4Doñana Biological Station, Spanish National Research Council (CSIC), Sevilla, Spain (veronika.huber@ebd.csic.es)
- 5Institute of Epidemiology, Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- 6Santé Publique France, French National Public Health Agency, Department of Environmental and Occupational Health, Saint-Maurice, France
- 7Université de Lausanne, Lausanne, Switzerland
- 8Center for Climate Systems Modeling (C2SM), Zurich, Switzerland
- 9European Centre for Medium-Range Weather Forecasts (ECMWF), Bonn, Germany
Countless heat records were broken in recent years, leading to thousands of heat-related deaths. This raises the question of how much worse heat-related mortality could become in coming years if a potential worst-case heatwave lasts for several weeks or reaches unprecedented intensity. Here, we develop impact storylines for worst-case heatwaves and associated heat-related mortality in France, Germany, and Switzerland.
We compare several physical climate storyline approaches to quantify plausible extreme heatwaves and combine these with empirical heat-mortality relationships. The storylines are based on (a) using a Single-Model Initial Condition Large Ensemble (SMILE), (b) ensemble boosting, and by looking for the most extreme events (UNSEEN approach) in the initialized (c) 45-day sub-seasonal re-forecast and (d) 7-months seasonal forecasting system using the ECMWF Integrated Forecast System (IFS).
In all four approaches we find physically consistent week-long heatwaves possible in the climate of 2020 that exceed the observed 7-day record temperatures by more than 5°C and associated mortality impacts exceeding the observed maximum by 30-90%. Even more severe consequences would arise from possible five-week heat periods of unprecedented intensity, which would lead to more than a doubling of impacts. Developing these impact storylines can inform the stress-testing of socio-economic systems for preparing appropriate emergency response capacities.
How to cite: Vicedo Cabrera, A. M., Luthi, S., Huber, V., Pascal, M., Beyerle, U., Pyrina, M., Domeisen, D., and Fischer, E.: Storylines for month-long heatwaves and associated heat-related mortality impacts over Western Europe, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20537, https://doi.org/10.5194/egusphere-egu25-20537, 2025.
