Exploring extreme event attribution by using long-running meteorological observations

Despite a growing interest in extreme event attribution, attributing individual weather events remains difficult and uncertain. We have explored extreme event attribution by comparing a widely adopted method for probabilistic extreme event attribution to a more analogue approach utilising the extensive, and long-running, network of meteorological observations available in Sweden. The long observational records enabled us to calculate the change in probability for two recent extreme events in Sweden without relying on the correlation to the global mean surface temperature, as is usually done in the reference method. Our results indicate that the two methods generally agree on the sign of attribution for an event based on daily maximum temperatures. However, the reference method results in a weaker indication of attribution compared to the observations, where 12 out of 15 stations indicate a stronger attribution than found by the reference method. On the other hand, for a recent extreme precipitation event, the reference method results in a stronger indication of attribution compared to the observations. For this event, only two out of ten stations exhibited results similar to the reference method.