Skill and relative economic value of the ECMWF ensemble prediction system
Article first published online: 15 DEC 2006
Copyright © 2000 Royal Meteorological Society
Quarterly Journal of the Royal Meteorological Society
Volume 126, Issue 563, pages 649–667, January 2000 Part B
How to Cite
Richardson, D. S. (2000), Skill and relative economic value of the ECMWF ensemble prediction system. Q.J.R. Meteorol. Soc., 126: 649–667. doi: 10.1002/qj.49712656313
- Issue published online: 15 DEC 2006
- Article first published online: 15 DEC 2006
- Manuscript Revised: 22 JUN 1999
- Manuscript Received: 8 OCT 1998
- Numerical weather prediction;
- Probability forecasts
The economic value of the European Centre for Medium-Range Weather Forecasts (ECMWF) operational ensemble prediction system (EPS) is assessed relative to the value of a perfect deterministic forecast. The EPS has substantial relative value throughout the medium range. Probability forecasts derived from the EPS are of greater benefit than a deterministic forecast produced by the same model. Indeed, for many users, the probability forecasts have more value than a shorter-range deterministic forecast. Based on the measures used here, the additional information in the EPS (reflecting the uncertainty in the initial conditions) provides a benefit to users equivalent to many years' development of the forecast model and assimilation system.
The impact of ensemble size on forecast value is considered. The difference in performance between ensembles with 10 and with 50 members may appear relatively small, based on standard skill measures, yet the larger ensembles have substantial benefit to a range of users. Further increases in ensemble size may be expected to provide additional value.