Climate system models have typically been restricted to grid resolutions from a few hundred kilometers down to a few tens of kilometers owing to computational constraints, and a representation of subgrid physical processes by parameterization is required. The continuing advances of science and technology are allowing larger computations and higher horizontal resolution for weather forecasting and climate models toward the kilometer scale. However, at resolutions ranging from 1 to 10 km, several physical processes are partially but not fully represented by the resolved dynamics and therefore still need to be partly parameterized in an appropriate way. The traditional scale separation assumptions between resolved and unresolved subgrid processes break down for this intermediate range of resolutions, known as the “grey zone,” requiring the development of new parameterizations. To increase the knowledge and training of a new generation of researchers working on the development of climate models suitable for grey zone resolutions, the World Climate Research Programme (WCRP) promoted the Second WCRP Summer School1 on Climate Model Development: Scale-Aware Parameterization for Representing Subgrid-Scale Processes. A scientific committee evaluated a large number of applications and the potential relevance of each application to the summer school objectives was discussed. Throughout the selection process, the board considered the potential knowledge transfer as an important factor. In particular, improving and increasing climate modeling capabilities in developing countries was an additional aim of the summer school. Most of the 30 early career researchers (ECRs) selected came from the weather and climate communities in Argentina, Brazil, and Peru. Other selected participants came from Pakistan, India, and Japan. Full and partial financial support was offered to some candidates by WCRP and the Brazilian National Council for Scientific and Technological Development [Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)]. The participants were encouraged to visit the precourse web page, which included lectures from the First WCRP Summer School on Climate Model Development: The Representation of Atmospheric Moist Processes. A basic knowledge of the representation of cloud and convective processes in climate models was a requirement for the 2018 school. Through 11 lecturers and 9 keynote speakers from Europe, the United States, and Brazil, the school offered 35 hours of topical presentations, including 6 remote talks and 14 hours of interactive practical activities. Online livestream content allowed for remote viewing of all presentations and discussions. A poster session with students’ presentations brought together senior experts and ECRs and provided the opportunity to engage in scientific discussions around the ECR research topics. The school also included a presentation on the Young Earth System Scientists Community (YESS; www.yess-community.org) which illustrated possibilities and advantages for ECRs to become engaged in ECR networks.