Scaling of Short‐Duration, Summer Rainfall Event Temporal Profiles With Warming Over Great Britain

The relationship between extreme rainfall and temperature, known as temperature scaling, is widely used to understand changes in rainfall characteristics under a warming climate. While most previous studies have focussed on fixed-duration intensities or event totals, this study examines how different aspects of the rainfall temporal profile respond to temperature. Specifically, we focus on temperature scaling of total event depth, maximum sub-hourly intensity and measures of profile concentration and loading. Using both sub-hourly rain gauge data across Britain and 10-min output from a convection-permitting climate model (CPM) for present and future climates over southern England and Wales, we analyse short-duration, summer rainstorms. Results show that total rainfall depth increases with temperature, with higher quantiles approaching Clausius-Clapeyron (CC) scaling rates of 6–7%°C$^{−1}$. However, changes are unevenly distributed within the rainfall event temporal structure. Maximum sub-hourly intensities scale more strongly than total event depth, with upper quantiles reaching 7–11%°C$^{−1}$, indicating pronounced intensification of short-duration rainfall extremes at high temperatures. ... mehrAccumulation of 50% of the rainfall event volume was found to occur over a shorter fraction of the storm duration and earlier in the storm duration, indicating rainfall events are more concentrated and more front-loaded at higher temperatures, with both scaling at rates of 1–2%°C$^{−1}$. These results suggest that future summer rainstorms will not only deliver greater overall rainfall in a warming climate, but also produce more intense and earlier bursts of precipitation, heightening flash flood risk. Disregarding these temporal shifts may lead to underestimation of flood hazards and misrepresentation of climate change impacts in hydrological modelling and infrastructure design.