EUROBRISA emerged from the 2001-2005 Ph. D work of Caio Coelho at the Department of Meteorology of the University of Reading. The aim was to develop statistical methods for improving the quality of probabilistic South American rainfall seasonal forecasts. Caio Coelho was supervised by Dr. David B. Stephenson and Dr. Francisco J. Doblas-Reyes and also worked in collaboration with Dr. Magdalena A. Balmaseda. They jointly developed a Bayesian framework known as FORECAST ASSIMILATION for calibrating and combining predictions. This framework allows the integration of empirical and coupled ocean-atmosphere model forecasts to produce a single well-calibrated probabilistic forecast.

The approach was developed and tested in three stages:

First, the approach was developed and applied to forecasts of an ENSO index (Nino-3.4) obtained from the European Centre for Medium-Range Weather Forecasts (ECMWF) coupled model (Coelho et al. 2004). The same method was used by Coelho et al. (2003) to assess the skill of Nino-3.4 index forecasts produced by four versions of the ECMWF seasonal forecasting system.

Next, the method was extended for the calibration and combination of equatorial Pacific sea surface temperature forecasts produced by seven DEMETER coupled models (Stephenson et al. 2005). The approach is now able to treat multi-model gridded forecasts.

Finally, the Bayesian forecast assimilation approach was applied to spatial field multi-model forecasts of rainfall over South America (Coelho et al. 2005a, Coelho et al. 2005b and Coelho et al. 2006a).

Coelho et al. (2005a,b) and (2006a) applied forecast assimilation to South American rainfall seasonal forecasts produced by an empirical model and three DEMETER coupled models (ECMWF, Met Office and Meteo-France). These three models are now used at ECMWF to compose the European real-time multi-model seasonal forecasting system. Combined and calibrated South American rainfall forecasts obtained with forecast assimilation have been shown to have improved skill when compared to either empirical or coupled multi-model forecasts alone. Coelho et al. 2006b successfully applied forecast assimilation for multi-model seasonal forecast downscaling of regional rainfall and river flows in South America.

These encouraging results stimulated the establishment of EUROBRISA, which will implement the Bayesian forecast assimilation procedure at the Centre for Weather Prediction and Climate Studies (CPTEC). EUROBRISA will use forecast assimilation to calibrate and combine real-time South American seasonal forecasts produced by both the operational European multi-model seasonal forecasting system and the CPTEC coupled model. EUROBRISA activities are scheduled to start in July 2006. The use of seasonal forecasts for non-profitable governmental applications is planned within EUROBRISA. Additional information is available in the EUROBRISA proposal, which was approved by ECMWF council in June 2005.