This ICTP school will introduce the Copernicus climate services platform that now provides open access to state of the art reanalysis, real-time seasonal forecast and climate model products. Daily lectures will be given on reanalysis, subseasonal to seasonal forecasting, and predictability, including lectures on ENSO-driven variability and teleconnections. Each afternoon will be spent carrying out hands-on exercises using state-of-the-art products now available on the Copernicus climate data store hosted at ECMWF. These exercises will demonstrate how to access files through python scripts or perform analysis directly at ECMWF using the python-based toolbox. The aim would be to assess some aspect of the seasonal forecast skill in a participants’ projects during the ICTP school in week 1. Topics: • Analysis and Reanalysis products • Sub seasonal to Seasonal forecasting • Predictability, ENSO and teleconnections • Copernicus climate services and the data store