ECMWF will celebrate 20 years of operational ensemble prediction at ECMWF on Monday, 3 December 2012. Twenty years ago, on 24 November 1992, the first ensemble predictions were produced under the operational suite.
At that time, the Ensemble Prediction System (EPS) was run three times a week, on Fri-Sat-Sun, with 33 members with a T63L19 resolution up to 10 days. Today, the EPS runs twice a day with 51 members at resolution T639L62 to day 10, and T319L62 from day 10 to 15. It uses a coupled ocean-atmosphere model and is extended to 32 days twice weekly. It is recognized as providing the best global medium-range and monthly probabilistic forecasts. 'Spaghetti' maps are now firmly on the table of most forecasters!
We have decided to celebrate 20 years of EPS with an afternoon of talks from people who contributed to our work, either developing the system that went operational, or contributing to the science on which it is based.