You may want to run the models individually to calibrate each model to observed data before doing a full compute of the forecast run. 

For HEC-HMS, you will need to compare model results to observed hydrographs to determine if you need to adjust model parameters (loss rate, baseflow, etc.) to better match observed data. 

In the case of HEC-ResSim, you are using the simulated releases as a guide. After reviewing the releases, you might decide that you need to adjust the releases to better simulate actual reservoir operations.

For HEC-RAS, you should check profile and hydrograph plots throughout the lookback period. If results are not satisfactory, you can calibrate HEC-RAS by modifying Manning's n values at selected cross sections.

In the case of HEC-FIA, you might need to adjust the levee failure stages to see the associated damage and impacts during an event.

Computing Individual Model Alternatives

To run a forecast through an individual model: 

  1. From the Forecast Runs Detail section of the Modeling module, right-click on a model alternative of a forecast run. From the shortcut menu, click Compute. Note that the models are computed in the same order as the Program Order you have set up for your watershed. For example, if you want to compute a forecast run through the HEC-ResSim model alternative, right-click on the HEC-ResSim model alternative and choose Compute from the shortcut menu.
  2. The Compute Progress dialog opens and CWMS begins execution of CWMS programs up to the model that you have chosen. 

After the compute is complete, you will need to review reports to help in your calibration. CWMS Results describes in detail the available reports for each individual model.

Editing Individual Model Parameters

After you have made your initial run and reviewed results, you might decide to edit parameters for an individual model. From the Forecast Runs Detail section, right-click on a model alternative and the shortcut menu will display a range of editing options depending on the model you selected. For example, if you right-click on the HEC-HMS model alternative, you will see options to edit baseflow, routing, and loss parameters. More details can be found in Model Alternatives and Forecast Runs.