This guide walks you through the steps to edit an HEC-MetVue alternative within your HEC-RTS watershed. 

Step 1: Access the MetVue Alternative Editor Dialog

  1. Launch HEC-RTS and open your watershed.
  2. Navigate to the Setup module.
  3. In the Watershed Tree, expand the MetVue node.
  4. Right-click an existing HEC-MetVue alternative and select Edit MetVue Alternative.
  5. The MetVue Alternative Editor dialog will open.

Step 2: Configure Input Settings

  1. Click the Input Settings tab.
  2. Set the Lookback and Forecast checkboxes for each Map Panel:
    1. Check Lookback for observed data (e.g., QPE, Observed Temperature).
    2. Check Forecast for forecasted data (e.g., QPF, Forecast Temperature).

  3. Set Start of Simulation (SoS) Offsets and End of Forecast (EoF) Offsets:
    1. Choose the interval from the Interval column.
    2. Enter offset values in the corresponding columns.

      If using the Gridded Hamon ET method in your HEC-HMS model, set the Observed Temperature SoS offset to -1 days and the Forecast Temperature EoF offset to 1 days. See the HEC-HMS Users Manual for more information.

  4.  Ensure the Basin Average Maps shapefile is visible: 
    1. Select a Map Panel from the top of the window.
    2. Click each panel individually to display/set the Basin Average Map.
    3. If no map displays, open the HEC-MetVue model and assign a Basin Average Map (see step 3 of Creating an HEC-Metvue Project).
  5. From the TIN/Grid Input dropdown, choose DSS.

  6. Confirm the correct pathname is set for the selected Map Panel:
    1. You can type the pathname in the individual part or click Browse to select from a HEC-DSS file.
    2. Using Browse will automatically set the correct duration.
  7.  Click Apply to save your input settings.

Step 3: Configure Output Settings

  1. Go to the Output Settings tab.
  2.  Click Add to create a new dataset.
  3. Configure the dataset:
    1. Dataset Name: use a descriptive name (e.g., QPF_Precipitation).

    2. Parameters and Units: 
      1. Precipitation: Parameter = Precip, units = mm (unless using a non-standard project).
      2. Temperature: Parameter = AirTemp, units = deg C (unless using a non-standard project).
        1. Temperature datasets must use the parameter AirTemp for compatibility with HEC-HMS.
  4. Select maps for the dataset:
    1. Lookback Map: Choose from a Lookback dataset (marked on the Input Settings tab).
    2. Forecast Map: Choose from a Forecast dataset (marked on the Input Settings tab).
    3. If maps are missing, return to the Input Settings tab and ensure the data is marked as Lookback or Forecast. 
  5. Set the Time Zone:
    1. Click the ellipsis (...) in the Time Zone box to choose an option. 
    2. Common options are UTC or GMT.

  6. Choose the Output Time Interval and Parameter Type:
    1. Precipitation: Time Interval = 1Hour, Parameter Type = PER-CUM.
    2. Temperature: Time Interval = 1Hour, Parameter Type = INST-VAL. 
  7. Choose an Output Extents shapefile:
    1. Select from those listed in the From Map dropdown (linked previously in HEC-MetVue).
    2. If needed, load additional shapefiles (see step 3 in Creating an HEC-Metvue Project).
  8. Enable Save Modified TINs to DSS:
    1. The DSS pathname and parts auto-fill, except for the B Part. 
    2. Enter a B Part that matches what HEC-HMS expects (or adjust it in model linking).
    3. Alternatively, use Browse to select an existing path from the forecast.dss file.

  9. Optionally, enable Time Series Generation:
    1. Check Generate Time Series.
    2. Select a sub-basin name from the dropdown.
      1. Using sub-basin names allows for closer inspection and calibration.
  10. Click Apply to save your output settings.

Step 3: Final Review

  1. Review the Warnings box in both tabs:
    1. Ensure no errors or missing settings are listed.
    2. If needed, make edits until all errors disappear.
  2. Click Apply to save changes and OK to close the dialog.