Relationship Between Circulation Types and Extreme Precipitation Over Scandinavia Is Stable Under Climate Change

The atmospheric large-scale environment determines the occurrence of local extreme precipitation, and it is unclear how climate change affects this relationship. Here we investigate the present-day relationship between large-scale circulation types (CTs) and daily precipitation extremes over Scandinavia and its future change. A 50-member EC-Earth3 large ensemble is used to assess future changes against internal variability. We show that CTs are related to extreme precipitation over the entire domain. The intensity of extreme daily precipitation increases in all seasons in the future climate, generally following the strength of warming in the six different future scenarios considered. However, no significant future change is found in the relationship between extreme precipitation and the CTs in any season or scenario. The results have important implications for applications that rely on the stability of this relationship, such as statistical and event-based dynamical downscaling of future weather and climate predictions and long-term climate projections. The occurrence of local devastating extreme precipitation events is influenced by the large-scale flow of the atmosphere, that is, high- or low-pressure systems and winds from different directions. Understanding this connection helps us to predict precipitation extremes using more readily available information about the large-scale flow. However, it is not known if the relationship that we observe in the present climate will hold under future climate conditions. Here we study the present-day relationship between the large-scale flow and local precipitation events over Scandinavia and analyze how it will change toward the end of the 21st century. We find that extreme precipitation events become more intense over entire Scandinavia in the future climate, but their connection to the large-scale environment remains unchanged. Large-scale circulation types (CTs) can be used as precursors of local extreme precipitation events over Scandinavia The intensity of extreme precipitation events over Scandinavia increases with the warming strength in the future climate The relationship between extreme precipitation and CTs remains unchanged over Scandinavia in the future climate