Using ECMWF's Forecasts (UEF2022)

ECMWF plans to introduce the next major upgrade of its seasonal forecasting system, SEAS6, in 2024. Increased computing resources will allow us to improve the range and structure of the forecasts and supporting re-forecasts. This can be done in various ways - increased ensemble sizes, more frequent issuing of forecasts, longer forecast ranges for ENSO outlooks, and an increased range of years for reforecasts. Since computational resources are limited, choices must be made as to the balance between these different enhancements. The costs of different options are known, some being relatively cheap and others very expensive. ECMWF can also estimate the benefits of different choices in terms of reduced sampling errors and increased precision in forecast pdfs. However, our decisions should also take account of the usefulness of the various options. To gain information on this we have run a User Consultation to understand the views and priorities of users and potential users of ECMWF seasonal forecasts. This talk will present the plans and options for SEAS6, and results from the User Consultation.