Efficiency of using meteorological forecasts in river runoff forecasting methods

A quantitative assessment of the efficiency of using meteorological forecasts in river runoff forecasting methods is proposed. Examples of such assessment are provided for long- and short-term forecasts of various water inflow characteristics for the Cheboksary Reservoir and river runoff of the Oka and Kama basins and the Black Sea coast of the Caucasus. These forecasts were generated using the ECOMAG, DWAT, and HBV hydrological models, an ensemble approach, and the COSMO-Ru operational system. It is shown how the efficiency of using meteorological forecasts depends on the reliability and representativeness of available hydrometeorological information, the adequacy of the river runoff formation model, the degree of influence of weather conditions and the accuracy of their prediction on the resulting forecast during the lead time period. A possibility of significantly reducing hydrological forecasting errors even when using low-accuracy meteorological forecasts is demonstrated.