Probabilistic seasonal forecasts of droughts with a simplified coupled hydrologic-atmospheric model for water resources planning

Because of the nonlinear processes and interactions of the hydroclimatic system, a given hydroclimatic event has an associated probability distribution of possible hydrologic response that changes in space and time. An initial approach in quantifying these evolving probability distributions for use in water resources planning utilizes a simplified climate model. The simplified climate model incorporates the salient physics of the hydroclimatic system for the midlatitudes of the Northern Hemisphere. Using a Monte Carlo format with random initial conditions for the model state variables, hydrologic system response associated with a selected hydroclimatic event is quantified. A case study is presented that utilizes results from the simplified climate model to provide probabilistic seasonal forecasts for water resources planning.