The European Centre for Medium-Range Weather Forecasts (ECMWF) is an international organization specializing in global numerical weather predictions and climate data services. Known for its advanced high-performance computing (HPC) facilities and vast data repository, ECMWF leads in producing high-quality weather forecasts and climate reanalysis for Europe and beyond. In the MeDiTwin project, ECMWF is leading the creation of the Mediterranean digital twin prototype, over the cloud/High-Performance Computing (HPC) to simulate climate extremes and enhance the current predictive accuracy.