Added value of convection-permitting models for precipitation in the CORDEX FPS-Convection ensemble

The CORDEX Flagship Pilot study on Convective phenomena at high resolution over Europe and the Mediterranean, comprises a set of high- and very-high kilometre-scale resolution simulations over central Europe. This unprecedented multi-model ensemble, driven by the ERA-Interim reanalysis, constitutes a benchmark and reflects the growth in computational resources in recent years. The present study applies the Distribution Added Value (DAV) metric to assess and evaluate the quality of the precipitation distribution from convection-permitting regional climate models (CPRCM) relative to both their driving simulations counterparts and coarser-resolution ERA-Interim. The gains associated to CPRCMs are substantial, particularly when evaluated against higher-resolution observational products and station measurements. Widespread gains exceeding 10 % are obtained throughout the domain, with the coastal mediterranean demonstrating higher values. The benefits are also evident for precipitation extremes relevant to convective processes, for values above the observational 95^th and 99^th daily percentiles at both resolutions, with gains well above a DAV of 40 % for most situations. However, limitations in the observational datasets, which are unable to adequately capture the high-intensity events, may favour the evaluation of lower-resolution simulations and hinder a robust assessment for both precipitation full distribution and precipitation extremes. Furthermore, the improvements of CPRCMs relative to intermediate-resolution simulations are more limited for all cases, as the former depend on information inherited from the latter and the performance of the regional climate models is already comparatively high. The analysis also focuses on hourly precipitation, enabling a direct evaluation of the added value from high-resolution modelling in representing the short-duration precipitation characteristics and extremes.

 

 

This work is supported by FCT, I.P./MCTES through national funds (PIDDAC): LA/P/0068/2020 - https://doi.org/10.54499/LA/P/0068/2020, UID/50019/2025, https://doi.org /10.54499/UID/PRR/50019/2025, UID/PRR2/50019/2025. The authors would like also to acknowledge the project “Elaboração do Plano Municipal de Ação Climática de Barcelos (PMACB).