14. FAQ

14.1. 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 lines to the config.sh script before running the generate_FV3LAM_wflow.sh script:


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.sh. This means that the workflow will run the make_grid, make_orog, and make_sfc_climo tasks by default.

14.2. How do I define an experiment name?

The name of the experiment is set in the config.sh file using the variable EXPT_SUBDIR. See Section and/or Section 9.4 for more details.

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

The SDF is set in the config.sh file using the variable CCPP_PHYS_SUITE. When users run the generate_FV3LAM_wflow.sh 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 9.15

14.4. 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
201905200000       make_grid      9443237   QUEUED              -      0      0.0
201905200000       make_orog            -        -              -      -        -
201905200000  make_sfc_climo            -        -              -      -        -
201905200000   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), users can re-run the failed task using the rocotorewind command:

rocotorewind -w FV3LAM_wflow.xml -d FV3LAM_wflow.db -v 10 -c 201905200000 -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.

14.5. How do I change the grid?

To change the predefined grid, modify the PREDEF_GRID_NAME variable in the config.sh script (see Section for details on creating and modifying the config.sh file). Users can choose from one of four predefined grids for the SRW Application v2.0.0 release:


An option also exists to create a user-defined grid, with information available in Chapter 8.2. However, the user-defined grid option is not fully-supported for this release and is provided for informational purposes only.