Stochastic simulation and forecasting of hydroclimatic processes, such as precipitation and streamflow, are vital tools for risk-based management of water resources systems. Stochastic hydrology has a long and rich history in this area. The traditional approaches have been based on mathematical models with assumed or derived structure representing the underlying mechanisms and processes involved. The model generally includes several variables and a parameter set. Such "parametric models" have been quite useful in practice for analyzing and synthesizing hydrologic time series at various timescales. A lot of experience has been gained using such "traditional techniques" with