17. FAQ

17.1. How do I define an experiment name?

The name of the experiment is set in the workflow: section of the config.yaml file using the variable EXPT_SUBDIR. See Section and/or Section 11.3.2 for more details.

17.2. How do I change the Physics Suite Definition File (SDF)?

The SDF is set in the workflow: section of the config.yaml file using the variable CCPP_PHYS_SUITE. The four supported physics suites for the SRW Application as of the v2.1.0 release are:


When users run the generate_FV3LAM_wflow.py script, the SDF file is copied from its location in the forecast model directory to the experiment directory $EXPTDIR. For more information on the CCPP physics suite parameters, see Section 11.3.5.

17.3. How do I change the grid?

To change the predefined grid, modify the PREDEF_GRID_NAME variable in the task_run_fcst: section of the config.yaml script (see Section for details on creating and modifying the config.yaml file). The four supported predefined grids as of the SRW Application v2.1.0 release are:


However, users can choose from a variety of predefined grids listed in Section 11.12.5. An option also exists to create a user-defined grid, with information available in Chapter 10.2. However, the user-defined grid option is not fully supported as of the v2.1.0 release and is provided for informational purposes only.

17.4. How do I turn on/off the cycle-independent workflow tasks?

The first three pre-processing tasks make_grid, make_orog, and make_sfc_climo are cycle-independent, meaning that they only need to be run once per experiment. If the grid, orography, and surface climatology files that these tasks generate are already available (e.g., from a previous experiment that used the same grid as the current experiment), then these tasks can be skipped, and the workflow can use those pre-generated files. This can be done by adding the following parameters to the appropriate sections of the config.yaml script before running generate_FV3LAM_wflow.py:

   GRID_DIR: /path/to/directory/containing/grid/files
   OROG_DIR: /path/to/directory/containing/orography/files
   SFC_CLIMO_DIR: /path/to/directory/containing/surface/climatology/files

The RUN_TASK_MAKE_GRID, RUN_TASK_MAKE_OROG, and RUN_TASK_MAKE_SFC_CLIMO flags disable their respective tasks. GRID_DIR, OROG_DIR, and SFC_CLIMO_DIR specify the directories where pre-generated grid, orography, and surface climatology files are located (all three sets of files may be placed in the same directory location). By default, the RUN_TASK_MAKE_* flags are set to true in config_defaults.yaml. This means that the workflow will run the make_grid, make_orog, and make_sfc_climo tasks by default.

17.5. How do I restart a DEAD task?

On platforms that utilize Rocoto workflow software (such as NCAR’s Cheyenne machine), if something goes wrong with the workflow, a task may end up in the DEAD state:

rocotostat -w FV3SAR_wflow.xml -d FV3SAR_wflow.db -v 10
201906151800       make_grid      9443237   QUEUED              -      0      0.0
201906151800       make_orog            -        -              -      -        -
201906151800  make_sfc_climo            -        -              -      -        -
201906151800   get_extrn_ics      9443293     DEAD            256      3      5.0

This means that the dead task has not completed successfully, so the workflow has stopped. Once the issue has been identified and fixed (by referencing the log files in $EXPTDIR/log), users can re-run the failed task using the rocotorewind command:

rocotorewind -w FV3LAM_wflow.xml -d FV3LAM_wflow.db -v 10 -c 201906151800 -t get_extrn_ics

where -c specifies the cycle date (first column of rocotostat output) and -t represents the task name (second column of rocotostat output). After using rocotorewind, the next time rocotorun is used to advance the workflow, the job will be resubmitted.

17.6. How can I clean up the SRW App code if something went wrong?

The ufs-srweather-app repository contains a devclean.sh convenience script. This script can be used to clean up code if something goes wrong when checking out externals or building the application. To view usage instructions and to get help, run with the -h flag:

./devclean.sh -h

To remove the build directory, run:

./devclean.sh --remove

To remove all build artifacts (including build, exec, lib, and share), run:

./devclean.sh --clean
./devclean.sh -a

To remove external submodules, run:

./devclean.sh --sub-modules

Users will need to check out the external submodules again before building the application.

In addition to the options above, many standard terminal commands can be run to remove unwanted files and directories (e.g., rm -rf expt_dirs). A complete explanation of these options is beyond the scope of this User’s Guide.

17.7. How can I run a new experiment?

To run a new experiment at a later time, users need to rerun the commands in Section 5.3.1 that reactivate the regional workflow python environment:

source <path/to/etc/lmod-setup.sh/or/lmod-setup.csh> <platform>
module use <path/to/modulefiles>
module load wflow_<platform>

Follow any instructions output by the console.

Then, users can configure a new experiment by updating the environment variables in config.yaml to reflect the desired experiment configuration. Detailed instructions can be viewed in Section Parameters and valid values are listed in Chapter 11. After adjusting the configuration file, generate the new experiment by running ./generate_FV3LAM_wflow.py. Check progress by navigating to the $EXPTDIR and running rocotostat -w FV3LAM_wflow.xml -d FV3LAM_wflow.db -v 10.