A forecast run is the set of model alternatives that run sequentially during a forecast. As the with model alternatives, forecast runs exist independent of time. Therefore, you can use a forecast run for any forecast time window.
You create a forecast run by selecting a model alternative for each HEC-RTS software application. There are five standard software applications in HEC-RTS, a typical forecast run will include a combination of the five model alternatives. When you execute a forecast, HEC-RTS executes the software applications in a sequential order (program order).

The table shows three suggested forecast runs. The codes are the names HEC-RTS automatically assigns to each forecast run based on the one-character Model Alternative Keys you have assigned to the model alternatives. This coding is program order dependent.

In the following example, the forecast alternative named Two times QPF has the code SWRBE. Each character in this code is the ID of a specific model alternative for each of the five standard software applications in HEC-RTS. The code translates as follows:

Creating Forecast Run

Before this step can be done, you must have created model alternatives.

Creating forecast runs:

1. From the HEC-RTS main window, click on the Setup tab, from the Models menu, click Forecast Runs, and the Forecast Run Editor (Figure 1) opens.
   
2. Click New Run (Figure 1), enter a new forecast run name in the Name field (required), and a description in the Description field (optional).
3. Select program order from the Program Order list (Figure 1). See Chapter 16 for information on program order.
4. From each program list (Figure 1), select the model alternatives for the forecast run.
5. From the File menu, click Save. The new forecast alternative displays in the table on the Forecast Run Editor (Figure 1).
6. Click OK, and the Forecast Run Editor closes. Be sure to save your HEC-RTS study.

Delete a Forecast Run

Delete a forecast run:

1. From the HEC-RTS main window, click on the Setup tab, from the Models menu, click Forecast Runs, and the Forecast Run Editor (Figure 1) opens.
2. From the table, select the forecast run you want to delete. From the Forecast Run menu, click Delete. A Delete Forecast Runs window will open, asking do you really want to delete the selected forecast run.
3. Click Yes, the Delete Forecast Runs window will close, and the forecast run will be removed from the table on the Forecast Run Editor.
4. Click OK and the Forecast Run Editor closes. Be sure to save your HEC-RTS study.