WRF Restart Files

File type abbreviation: wrfrst

Restart files for re-running the LES simulations from an arbitrary point during the simulation are available every 30 minutes. Restart files were not output for the mesoscale simulations since they run sufficiently fast that users can rerun the entire mesoscale simulation in less than a day.

Performing a restart simulation requires two different downloads. The first is the input files that contain the run directory and boundary forcings, described above. The second is the restart file for the D3 and, optionally, D4 domain(s) for the desired restart time. It is possible to run D3 without D4, but not the other way around—rerunning D4 will require running D3 at the same time since they are nested together online.

Note that the filenames of the restart files will need to be changed from what is used when archiving the files versus what WRF expects for using them. Specifically, the archived filename will be similar to corlasso.wrfrst.2019012900gefs05d4.base.M1.m0.20190129.173000.nc, where the case date is encoded toward the left-hand side of the filename, 29-Jan-2019 00 UTC in this example, and the restart time is encoded toward the right-hand side of the filename, 29-Jan-2019 17:30 UTC. The equivalent WRF filename for this file is wrfrst_d02_2019-01-29_17_30_00. Note that the domain number, D4, is mapped to d02 for the online nesting (D3 would become d01), and the convention used for LASSO is to have underscores instead of colons in the filenames (no_colons=.true. in namelist.input). Full details regarding the file naming convention used for LASSO-CACTI files are in the File Naming Convention section.

With the restart files properly named and placed in the run directory provided with the input suite of files, the user should be able to proceed with the restart following the typical WRF workflow for doing restarts. The restart time will need to be updated in namelist.input, any other desired changes can be made to the code or configuration parameters, such as changing the output frequency, and a properly compiled wrf.exe executable will be required.

Note that many of the input tar files contain pre-compiled wrf.exe executable files that were originally used to run the simulations. However, some simulations were done on an earlier ARM computer that no longer exists. So, the executables may or may not work on the current ARM Cumulus cluster. Users can obtain copies of the WRF source code used for LASSO-CACTI from https://code.arm.gov/lasso/lasso-cacti/lasso-wrf-cacti, which can then be compiled for the machine where the restart will take place.