This is the case where one has run the model for some coarser grid(s), and would like to run the case again with a finer grid.

Work with any case you have previously run. In this exercise we are going to nest down to a second domain.
This exercise will overwrite a lot of your files, so keep copies of important files; specifically: wrfinput*, wrfbdy and wrfout*.
 

Below is a flow chart for a one-way nested run.

1. Before running ndown, make sure you have outfput files from a previous coarse domain run.
2. Run geogrid.exe and metgrid.exe for two domains
3. Run real.exe for two domains
4. ndown is run with output from 2 and 3 above
5. output from 4 above is input to wrf.exe (as if it was d01)