A statistical analysis is performed using the values obtained from each year's simulation in order to produce a probabilistic forecast for the streamflow variable.
This analysis can be recreated for different forecast periods and additional streamflow variables of interest.
Short-term quantitative forecasts of precipitation and temperature can be used to weight the years of simulated streamflow based on the similarity between the climatological conditions of each historical year and the current year.

ESP allows:

• flexibility in the streamflow variables which can be analyzed
• the capability to make forecasts over short and long time periods
• the ability to incorporate forecast meteorological data into the procedure

Because of the flexibility and conceptual basis of ESP, it has many applications including water supply and drought analysis.