Extreme Sub-Hourly Precipitation Intensities Scale Close to the Clausius-Clapeyron Rate Over Europe

Abstract

Over subhourly time scales, extreme precipitation events play a critical role for many sectors impacted by climate change; however, it is unclear how these events will evolve in a warmer climate. Here, we perform climate simulations using a regional climate model over the greater Alpine region at kilometer-scale resolution. By analyzing precipitation intensities with short accumulation times, we show that the model can capture the observed percentiles of extreme subhourly precipitation measured at surface rain-gauge stations. Then, by simulating the future climate, we show that the associated increases in intensity of subhourly extreme precipitation events grow with the intensity of the events but tends asymptotically toward 6.5% per degree warming. This suggests that the most extreme intensities scale with the Clausius-Clapeyron scaling rate that represents the ability of a warmer atmosphere to hold more water vapor. It should be expected that these changes will lead to increased risks of flash flooding, land-slides, and erosion over Europe in a warmer climate.