Development of a stochastic hydrological modeling system for improving ensemble streamflow prediction

•A stochastic hydrological modeling system (SHMS) is proposed for improving streamflow prediction.•Interactions of error parameters have significant contributions to model performance.•The SHMS improves upon the EnKF through a more accurate convergence of model parameters.•The SHMS improves upon the conditional vine copula model for probabilistic streamflow prediction.•Temporal dynamics of parameter sensitivity are examined using the time-varying sensitivity analysis.