Taking advantage of a large ensemble of Convection Permitting-Regional Climate Models on a pan-Alpine domain and of an object-oriented dedicated analysis, this study aims to investigate future changes in the high-impact fall Mediterranean Heavy Precipitation Events at high warming levels. We identify a robust multi-model agreement for an increased frequency from central Italy to the northern Balkans combined with a substantial extension of the affected areas, a dominant influence of the driving Global Climate Models for projecting changes in the frequency, an increase in intensity, area, volume and severity over the French Mediterranean. However, large quantitative uncertainties persist despite the use of convection-permitting models, with no clear agreement in frequency changes over southeastern France and a large range of plausible changes in events’ properties, including for the most intense events. Model diversity and international coordination are still needed to provide policy-relevant climate information regarding precipitation extremes.

As global temperatures continue to rise, the impact of heatwaves (HWs) becomes increasingly striking. The increasing frequency and intensity of these events underscore the critical need to understand regional-scale mechanisms and feedback, exacerbating or mitigating HW magnitude. Here, we use an ensemble of convection-permitting regional climate models (CPRCMs) to elucidate future HW changes at these fine spatial scales. We explore whether the recently highlighted drier/warmer signal introduced by CPRCMs improves summer temperature extremes representation and if it modulates future HW changes compared to convection-parameterizing regional climate models (RCMs). In historical runs, CPRCMs show a more realistic representation of summer maximum temperature according to a ground-station-based evaluation. CPRCMs project substantially drier conditions than RCMs. This is associated with a modulation of HW temperature changes which show diversified spatial patterns, magnitudes, and signs. CPRCMs ensemble shows an overall reduction in HW metrics future changes inter-model spread compared to the RCMs ensemble.