Basics: WRF

The WRF model has 2 steps:

real.exe
This program vertically interpolates the met_em* files (generated by metgrid.exe), creates boundary and initial condition files, and does some consistency checks.

wrf.exe
Generates the model forecast.

 

STEPS to Run WRF

1. Move to the directory in which you plan to run the code (either WRF/test/em_real or WRF/run).
       -Both the run/ and test/em_real/ directories will have all the files you need linked in,
       so it does not matter which one you choose to run the code in.
 
2. Link or copy (with the UNIX command ln or cp ) the met_em files to this directory.
       ln -sf path_to_met_em_files/met_em.d0* .
 
3. Edit the namelist.input file for your particular run. For descriptions of the namelist parameters, as well as suggestions for best practices, see our Best Practices WRF Namelist page.
 
4. Run real.exe (verify that the program runs correctly)
       -You should have the following output files (default setup): wrfinput_d01 & wrfbdy_d01
       -This is true for single domain and default nested runs.
       -If you plan to use a nested domain, you will have a wrfinput_dxx file for each domain.
       (more on this in 'nested case studies').
 
5. Run wrf.exe (verify that the program runs correctly)
       -You should have the following output files (default setup): wrfout_dxx_[initial_date] (one for each domain)
       -Each file (by default) will contain all the forecast output times.
 
6. Use a post-processing tool to view the output.

Do I need to re-run real.exe if a change to the namelist.input has been made? -Generally, you only need to run wrf.exe again; however, if you have changed the LSM packages you are running with, or have changed anything about the date/times or input data, then you must re-run real.exe again. real.exe runs very fast - so if in doubt, just go ahead and run real.exe again.

Let's run a real case study!!

Case Studies