WRF restart setting

[sd16121]

Dear Office,

I ran WRF without the settings below:
restart = .true.,
restart_interval = 1440,

If I modify this as
restart = .false.,
restart_interval = 1440,
during the running period (the wrfout file has not been output for 24 hours), is that ok?

I saw your guide at ARW Online Tutorial and ARW Online Tutorial, my understanding is that I should set
restart = .false.,
restart_interval = 1440,
then, after the restart file is generated, I could set
restart = .true.,
restart_interval = 1440,
So, the running process could be continued as usual. Could you please kindly confirm whether my understanding is correct?

Best wishes,
Stella

 

[Ming Chen]

Stella,
if you set
restart = .false.,
restart_interval = 1440,
It indicates this is an initial run and the model will output wrfrst files every 24-hr.

if you set
restart = .true.,
restart_interval = 1440,
It indicates this is a continuous run (restart run) and the model still will output wrfrst st 24-hr intervals.

You are right that after the restart file is generated, you can set
restart = .true.,
restart_interval = 1440,

and the the running process will continue as usual.

 

[sd16121]

Stella,
if you set
restart = .false.,
restart_interval = 1440,
It indicates this is an initial run and the model will output wrfrst files every 24-hr.

if you set
restart = .true.,
restart_interval = 1440,
It indicates this is a continuous run (restart run) and the model still will output wrfrst st 24-hr intervals.

You are right that after the restart file is generated, you can set
restart = .true.,
restart_interval = 1440,

and the the running process will continue as usual.

Hi Ming,

Could you please kindly explain the differences of "It indicates this is an initial run and the model will output wrfrst files every 24-hr" and "
It indicates this is a continuous run (restart run) and the model still will output wrfrst 24-hr intervals"? My WRF output file is hourly, do you mean WRF restart file here?

Because the time limit on my HPC is 14 days, and I need 33 days for my simulation, I hereby set the restart interval as 11 days:
restart = .false.,
restart_interval = 15840,
After I get the restart file, I will change the restart as "true".
Do I need to repeat running real.exe and wrf.exe again by myself? Or the only thing is to submit my job again? Do I need to modify other items in namelist file, such as start_year, start_month, start_day, start_hour, etc.?

Best wishes,
Stella

 

[sd16121]

Looking forward to hearing from you. Many thanks.

 

[Ming Chen]

Stella,
By 'initial run', I mean WRF simulation starts from the initial time of your integration period. For example, if you run a case over the period from 2021-09-01_00 to 2012-09-20_00 (a 20-day integration), you have wrfinput file at the time 2021-09-01_00. The initial run refers to the simulation starting from 2021-09-20_00, and data are read from wrfinput. A 'restart run' or 'continuous run' refers to the case that, for example, you have finished the first 10-day simulation, and you save wrfrst file at the end of the 10th day. Then you continue for the next 10-day simulation. The simulation period will be from 2021-09-11_00 to Y2021-09-20_00, you read data from wrfrst file at the time of 2021-09-11_00.

 

[wavy_turbines]

Hi @Ming Chen, I do not have a wrfrst file, instead I have a wrfout file with values at written out every 5 mins. So do i just change the namelist.input options restart = .true. and changing the simulation start date to the last stored time step in the wrfout file?

UPDATE: This does not work!

 

[Ming Chen]

@wavy_turbines
For a 'restart" WRF run (i.e., a continuous run), you must have wrfrst files saved. Otherwise, WRF cannot obtain enough information to continue the simulation from the previous run. For detailed description of 'restarting' WRF, please take a look at the WRF User's Guide:

Running WRF — WRF Users Guide documentation