Nested Runs - Ndown (ndown.exe and wrf.exe)

Run ndown.exe: STEP 3

1. Input

wrfout_d01_<date> from original single domain run, and
wrfndi_d02 from STEP 2
 

2. Add the following into your namelist.input file (under &time_control):

io_form_auxinput2 = 2

3. Run ndown.exe 
     

Output from this run: wrfinput_d02 and wrfbdy_d02

 

---

Run wrf.exe: STEP 4

1. RENAME wrfinput_d02 and wrfbdy_d02 to wrfinput_d01 and wrfbdy_d01, respectively.

2. RENAME (or move) the original wrfout_d01_<date>* files to a new file name, or to another directory (to prevent them from being overwritten)
 

2. Edit namelist.input, moving all of the fine-grid domain data from column 2 to column 1 so that this run will be for the fine-grid domain only. It may be beneficial to save namelist.input to something else prior to this step in case you need to repeat this process in the future. Save the newly-edited namelist as namelist.input .
 

3. Edit this namelist.input file for all other options you would like to use. Since this will be a single domain run, edit all options in column 1 only.

Two commonly forgotten variables to change are:
- max_dom (=1), and
- time_step (make sure this is set appropriately for this domain, i.e. 6 x the grid distance in km of this domain)
 

4. Run wrf.exe

Output: wrfout_d01_<date>
B: This is d02 output, even though the file name says d01
 

5. Check the contents of this file:

a. Use the ncdump utility:
    ncdump -h wrfout_d01_2016-10-06_00:00:00
b. Use the ncview utility.
c. This file can also be view with any of the supported graphical tools.

Run another case study