Regional climate modeling has become an established and grwoing area of research in the last decades. Regional Climate Models (RCMs) are powerful and flexible tools which can be used for a wide variety of problems at regional scales, from the study of regional processes and the interactions between atmosphere, biosphere and chemosphere/aerosols to paleoclimate simulations and future climate projections. The resolution of RCMs varies from a few tens of km to convection-permitting scales (a few km) and the length of simulation has reached the multi-centennial scales. Different RCM intercomparison projects have been crried out in the past, culminating in the Coordinated Regional Downscaling EXperiment (CORDEX), an international program aimed at better understanding and improving regional downscaling techniques and producing large ensembles of projections for domains worldwide. The results from CORDEX and other RCM initiative have been extensively used for impact applications and provide the basis for many climate service activities. Following a tradition of very successful and well attended EGU sessions in the past, this session accepts frontier papers on all aspects of regional climate modeling science and application, and on the latest results from the CORDEX project.