Once the models have been linked the next step is to configure the extract groups. An extract group specifies the location of the gridded and time series data required for the different model alternatives. For example, this could be gridded precipitation data in a HEC-DSS file or observed flow data from the CWMS database. Once you have completed computing your forecast, you might want to post results back to the CWMS database. This task is completed by creating post groups that specify what time series data needs to be posted (saved) back to the CWMS database. Refer to Data Extract and Post Editors for additional information.