Regional climate models (RCMs) are widely used tools to produce high resolution climate information at regional scales, and can be run at resolutions of a few km which allow explicit description of convection processes. The ICTP regional climate modeling system, RegCM, is one of the most used RCMs worldwide. Its latest version, RegCM4, has been recently augmented in several aspects, in particular towards the application of the model to very high resolution, convection permitting, simulations. Among the main model improvements in this direction are the implementation of non-hydrostatic dynamics, the refinement of an advanced explicit cloud microphysics scheme and the full coupling with the MIT ocean model, the CHYM hydrological model, the CLM4.5 land-surface model including interactive vegetation and an augmented version of a chemistry/aerosol module. As in previous workshops of this series, this event will provide lectures and extensive hands-on sessions on the theory of regional climate change and regional climate modeling as well as on the use of the RegCM4 modeling system. The focus of the present workshop will be on the application of the RegCM4 to high resolution experiments, in particular within the framework of the international program CORDEX (COordinated Regional Downscaling EXperiment). During the workshop, the new features of the model will be described and tested, and a new version of the model will be released. In addition, the contribution of the RegCM community to the next phase of the CORDEX program will be discussed. The workshop will also include a special session on the interactions between air quality, climate processes and climate change in diverse region of the world under the framework of the EU REQUA (Regional climate-air quality interactions) project. The workshop is also aimed at providing a forum for current and future model users to discuss relevant issues and formulate needs and priorities for further model development and dissemination. A limited number of participants are envisioned, with proven experience in climate modeling and a strong interest in using the RegCM4 system for regional climate studies.