In this example, while running wrf.exe you will increase the frequency of certain output variables using the Runtime I/O option.

There is no data pre-processing necessary. As long as you still have wrfinput_d01 and wrfbdy_d01 files from a previous case, you can continue. If not, please return to the Single Domain case and generate these again.

1. Edit the namelist.input file to add the variables listed below.
   
   

   Note The namelist for the standard case is perfect for this example. You just need to make a few changes (see below). To ensure the model runs fast, make sure max_dom=1. Setting io_form_auxhist24=2 will produce output in NetCDF format.

   
   
   
   

   &time_control iofields_filename = "myoutfields_d01.txt", io_form_auxhist24 = 2, auxhist24_interval = 30,

   
   
   



2. Now you need to make a .txt file called "myoutfields_d01.txt". Inside that file, you will declare the variables you wish to be output more frequently. For this exercise, you will request the output of RAINC, RAINNC, T2, and Q2 at an interval of every 30 mins. Inside the "myoutfields_d01.txt" file, simply type the following:

   +:h:24:RAINC,RAINNC,T2,Q2

   Notes Make sure there are no spaces in the text file, and then save it in the running directory. Note that if you are running a nested simulation, you will need to create a "myoutfields_*" file for each domain.




3. No need to run real.exe again, just run wrf.exe.
   
   If successful, in addition to your history and restart file, this will generate the following output file:
    
         auxhist24_d01_2019-11-25_12:00:00
         
    
   which will have the variables RAINC, RAINNC, T2, and Q2 at 30 minute intervals. You can view these variables by using 'ncview.'
   
   

Continue to More Exercises If you plan to attempt more exercises right now, you can access the cases studies menu by clicking here.