Future precipitation whiplash over Belgium from a high-resolution regional climate model

Abstract Precipitation whiplash events, characterized by rapid transitions between dry and wet extremes, are expected to intensify under climate change. However, current understanding of these events relies largely on coarse-scale climate models that cannot adequately resolve the physical processes driving abrupt hydroclimatic shifts. This study presents a high-resolution assessment of precipitation whiplash in Belgium using convection-permitting simulations from the ALARO regional climate model under three Representative Concentration Pathways scenarios (2.6, 4.5, and 8.5). We analyze both dry-to-wet and wet-to-dry transitions, focusing on projected changes in frequency, duration, transition speed, and seasonal timing. Results reveal increasing frequency and duration of both transition types, alongside shorter transition periods, indicating more abrupt shifts. Seasonal timing also changes, with a growing concentration of events, particularly dry-to-wet transitions, during spring and summer months. These projected changes pose heightened risks for climate-sensitive sectors, including agriculture, water management, and infrastructure, underscoring the need to consider the compound and abrupt nature of future hydroclimatic extremes in adaptation planning.