Regional Mountain Conference

In recent years, convection-permitting models have become a frequently used tool to study climate and climate change in regions with complex terrain. While convection-permitting models have been shown to add value for variables like wind and precipitation, temperature is rarely in the focus, despite being a key climate variable. In our research we evaluate the representation of minimum and maximum daily temperatures in the convection-permitting CORDEX-FPS Convection ensemble. Additionally, we compare the kilometer-scale, convection-permitting ensemble to its corresponding driving coarse-scale ensemble with grid spacings of 2.2-4 km and 12-15 km, respectively. We identify severe negative elevation-dependent biases ensemble at both resolutions, which become progressively worse at higher elevations. Further, both ensembles overestimate extremes like hot days and frost days, which is more pronounced in the convection-permitting ensemble. In our analysis, we found little to no added value of convection-permitting models in comparison to the convection-parameterizing regional climate models. This is underlined by the high spread across ensemble members which is present in both ensembles. Our results highlight that even at the convection-permitting scale, model tuning and adapting parameterizations remains crucial.