Current capabilities in Sub-seasonal to Seasonal Prediction

The main goals of this workshop are to establish current capabilities in sub-seasonal to seasonal prediction, to identify high-priority research topics and demonstration projects and to develop recommendations for the establishment of an international research project. Considerable progress has been made in improving the skill of medium range weather forecasts and in developing operational seasonal forecasting. Forecasting in the intermediate range between medium range and seasonal is difficult as the importance of the initial conditions wanes, and the importance of slower boundary conditions such as sea surface temperature increases but has only a modest influence on the weather and climate, especially away from the tropical regions. Tropical sea surface temperatures play an important role not only in controlling the weather/climate in the tropics but in the extra-tropics also, through various tele-connections. The El Nino Southern Oscillation (ENSO) is the best-known long-lived source of predictability in the tropics but changes in SST in the Indian Ocean are also significant, though the forecast horizon is likely to be shorter than for ENSO