Do Short-Duration Rainfall Extremes Intensify Faster? Evidence From CPM Simulations Over Europe

The climate change response from sub-hourly precipitation extremes remains poorly constrained because long, high-quality observational records at this resolution are scarce, and convection-permitting climate simulations at similarly high temporal resolution are computationally expensive. However, multiple recent observational analyses suggest that intensification with warming may be stronger for short accumulation periods than for longer events, with some regions exhibiting pronounced increases even when hourly or daily extremes show weak trends (for example, Utsumi et al., 2011; Ayat et al., 2022; Bauer and Scherrer, 2024). Given the relevance of short-duration rainfall for urban flash flooding and infrastructure design as described by Fowler et al. (2021), it is critical to assess whether an amplified intensification at sub-hourly scales is a robust feature.

Here, we investigate how extreme precipitation changes across accumulation periods from ten minutes to hours over an extended European domain, and how temperature scaling depends on event duration. We use the scClim convection-permitting simulations performed with COSMO at 2.2 km grid spacing, featuring 5-minute precipitation output over most of continental Europe (Cui et al., 2023). This unique combination of large spatial coverage and very high temporal resolution enables a consistent analysis of sub-hourly extremes across diverse climatic regimes.

We quantify changes in high percentiles of precipitation intensity for multiple accumulation periods (10 min to several hours) and relate them to near-surface temperature to diagnose scaling relative to Clausius–Clapeyron expectations.