The scope of this session is recent developments in the coupling between meteorological and hydrological models. As computational power increases and models become more detailed, the data flow between meteorological and hydrological models intensifies, creating new challenges in hydrometeorology and the structure of forecasting systems. At the same time, expectations from decision makers and the general public are increasing, raising demands for accurate and well-presented forecasts. This session welcomes contributions from modellers with experience of operational short-term real-time forecasting, as well as modellers with experience of long-term seasonal or climatic forecasting.

Major questions to be addressed include:
(i) can hydrological models currently utilise all information provided by meteorological models and remotely sensed data, including uncertainties and spatially distributed information?
(ii) how can updating procedures, including data assimilation, be optimised in operational forecasting?
(iii) what are the needs for post-processing when going from meteorological ensembles to hydrological ensembles?
(iv) how can benefits of ensemble hydrological forecasting be fully realised, including educating practitioners, communicating uncertainty and using probabilistic forecasts?
(v) how can the uncertainty represented by meteorological ensemble forecasts be distinguished from the uncertainty in the parameters and state variables of the hydrological model itself?
(vi) can hydrologic extreme events be forecasted satisfactory today? Case studies with positive/negative experiences.
(vii) how can seasonal or climatic meteorological forecasts be used as input to long-term hydrological forecasts?
what type of risk analysis can be used to provide support for decision makers?