“ECMWF is the European Centre for Medium-Range Weather Forecasts. We are both a research institute and a 24/7 operational service, producing global numerical weather predictions and other data for our Member and Co-operating States and the broader community. The Centre has one of the largest supercomputer facilities and meteorological data archives in the world. Other strategic activities include delivering advanced training and assisting the WMO in implementing its programmes. We are a key player in Copernicus, the Earth Observation component of the European Union’s Space programme, offering quality-assured information on climate change (Copernicus Climate Change Service), atmospheric composition (Copernicus Atmosphere Monitoring Service), flooding and fire danger (Copernicus Emergency Management Service), and through the EU’s Destination Earth initiative, we are developing prototype digital twins of the Earth. We provide global forecasts, climate reanalyses and specific datasets, designed to meet different user requirements. These are available via the web, point-to-point dissemination, data servers and broadcasting. ECMWF’s operational forecasts aim to show how the weather is most likely to evolve. To do this, the Centre produces an ensemble of predictions. Individually they are full descriptions of the evolution of the weather. Collectively they indicate the likelihood of a range of future weather scenarios.”