The ECMWF ensemble prediction system: Looking back (more than) 25 years and projecting forward 25 years

Abstract

This paper has been written to mark 25 years of operational medium‐range ensemble forecasting. The origins of the ECMWF Ensemble Prediction System are outlined, including the development of the precursor real‐time Met Office monthly ensemble forecast system. In particular, the reasons for the development of singular vectors and stochastic physics – particular features of the ECMWF Ensemble Prediction System ‐ are discussed. The author speculates about the development and use of ensemble prediction in the next 25 years.