The Ensemble Prediction System (EPS)

• The rationale behind the EPS
• The computation of the EPS
• EPS at different lead times
• Basic EPS products

The value of deterministic NWP forecasts would be greatly enhanced, if the quality of the forecasts could be assessed a priori; consequently, in parallel with improving the observational network, the data assimilation system and the models, methods of providing advance knowledge on how certain (or uncertain) a particular forecast is and what possible alternative developments might occur are being developed.