The next step after creating a forecast is to define the model linking for both the NoQPF and QPF forecasts.
Define the NoQPF Forecast Model Linking
From the Setup tab within the CAVI window, select Models → Model Linking...
Select the NoQPF Forecast Run and the MetVue-NoQPF option the Model Requiring Input.
All of the data that the HEC-MetVue model is expecting as inputs should be listed here. For the NoQPF forecast that includes observed & forecast temperature, observed precipitation and SWE grids.
Confirm that all of the expected inputs to the MetVue model are included in the model linking list.
Since the gridded data will be coming from outside of the CAVI (vs. from another model within the CAVI) it will be retrieved through an Extract List.
Verify that the model is expecting Input From the Extract List for all of the data and that each parameter pathname appears correct and looks like the screen shown above.
After verifying the MetVue-NoQPF model inputs, change the model model requiring input to HMS-Snow and review the list.
The HMS-Snow model linking list shows us that the HMS model is looking for gridded temperature, precipitation and SWE data as well as time series SWE data for the EG06_EauGalleLake subbasin.
HMS relies on MetVue to combine and process all of its gridded inputs as well as to generate the basin-average time series data (such as the SWE its looking for here). All of these inputs listed will come from the MetVue model, so the Input From selection must be updated.
Update the Input From Selection to the MetVue-NoQPF alternative and verify that the Location/Parameter list matches the one shown in the screen below.
Once the data has been verified, select Apply (if needed) to save any changes.
Define the QPF Forecast Model Linking
Next, select the QPF Forecast Run and the MetVue-QPF option as the Model Requiring Input.
The MetVue-QPF alternative has an additional dataset for forecast precipitation (FcstPrecip).
Confirm that all of the expected inputs to the MetVue model are included in the model linking list and the Input From is set to Extract List for each dataset. Select Apply (if necessary) to save any changes.
After verifying the MetVue-QPF model inputs, change the model model requiring input to HMS-Snow.
The following window (Select Model Linkages To Use) may appear:
The model linking editor recognizes that the HMS-Snow alternative within the QPF forecast is very similar (and in this case, identical) to the previous forecast (NoQPF) that was just updated and gives the user two options:
- Use Existing HMS Linkages: will apply the default assumptions and not consider any similar forecasts & their linking, or
- Use Linkages from a Forecast Run: gives the user the option to apply the linking from a similar forecast run to the current forecast.
Select the Use Linkages from a Forecast Run option, then select NoQPF from the list and OK.
Since the model linking was adopted from the NoQPF forecast, all inputs have been set to come from the MetVue alternative (MetVue-QPF) and the Location/Parameter fields also appear correct.
Model Linking has now been verified. Click Apply (if necessary) to save changes and OK to exit the Model Linking Editor.
Next, the gridded data inputs must be added to an Extract List from Cumulus in Part C, Task 3.