`ungrib`

Note

The uwtools drivers are idempotent, meaning that actions they successfully complete during one invocation are not repeated in subsequent invocations. For example, an asset like a configuration file will not be recreated when the driver is run again, even if its UW YAML configuration changes. To force recreation, remove the asset(s) in question – up to and including the entire provisioned run directory – then re-run the driver, which will recreate any missing assets based on the current configuration.

The uw mode for configuring and running the WRF preprocessing component ungrib. Documentation for this component is here.

uw ungrib --help

usage: uw ungrib [-h] [--version] [--show-schema] TASK ...

Execute ungrib tasks

Optional arguments:
  -h, --help
      Show help and exit
  --version
      Show version info and exit
  --show-schema
      Show driver schema and exit

Positional arguments:
  TASK
    gribfiles
      Symlinks to all the GRIB files
    namelist_file
      The namelist file
    provisioned_rundir
      Run directory provisioned with all required content
    run
      A run
    runscript
      The runscript
    show_output
      Show the output to be created by this component
    validate
      Validate the UW driver config
    vtable
      A symlink to the Vtable file

All tasks take the same arguments. For example:

uw ungrib run --help

usage: uw ungrib run --cycle CYCLE [-h] [--version] [--config-file PATH]
                     [--batch] [--dry-run] [--graph-file PATH]
                     [--key-path KEY[.KEY...]] [--schema-file PATH] [--quiet]
                     [--verbose]

A run

Required arguments:
  --cycle CYCLE
      The cycle in ISO8601 format (e.g. yyyy-mm-ddThh)

Optional arguments:
  -h, --help
      Show help and exit
  --version
      Show version info and exit
  --config-file PATH, -c PATH
      Path to UW YAML config file (default: read from stdin)
  --batch
      Submit job to batch scheduler
  --dry-run
      Only log info, making no changes
  --graph-file PATH
      Path to Graphviz DOT output [experimental]
  --key-path KEY[.KEY...]
      Dot-separated path of keys to driver config block
  --schema-file PATH
      Path to schema file to use for validation
  --quiet, -q
      Print no logging messages
  --verbose, -v
      Print all logging messages

Examples

The examples use a configuration file named config.yaml with contents similar to:

ungrib:
  execution:
    batchargs:
      cores: 1
      walltime: "00:01:00"
    executable: /path/to/ungrib.exe
  gribfiles:
    - /path/to/dir/rap.t00z.wrfnatf00.grib2
    - /path/to/dir/rap.t00z.wrfnatf06.grib2
    - /path/to/dir/rap.t00z.wrfnatf12.grib2
  rundir: /path/to/run/dir
  start: 2025-07-31T00:00:00
  step: 6
  stop: 2025-07-31T12:00:00
  vtable: /path/to/Vtable.GFS
platform:
  account: me
  scheduler: slurm

Its contents are described in depth in section ungrib.

Run ungrib on an interactive node
```
$ uw ungrib run --config-file config.yaml --cycle 2021-04-01T12
```
The driver creates a runscript.ungrib file in the directory specified by rundir: in the config and runs it, executing ungrib.
Run ungrib via a batch job
```
$ uw ungrib run --config-file config.yaml --cycle 2021-04-01T12 --batch
```
The driver creates a runscript.ungrib file in the directory specified by rundir: in the config and submits it to the batch system. Running with --batch requires a correctly configured platform: block in config.yaml, as well as appropriate settings in the execution: block under ungrib:.
Specifying the --dry-run flag results in the driver logging messages about actions it would have taken, without actually taking any.
```
$ uw ungrib run --config-file config.yaml --cycle 2021-04-01T12 --batch --dry-run
```

The --key-path option can be used to navigate from the top of the config to the driver’s configuration block. For example, specifying --key-path foo.bar with config
```
foo:
  bar:
    driver:
      # driver config block
```
is equivalent to using config
```
driver:
  # driver config block
```
without specifying --key-path.

The run task depends on the other available tasks and executes them as prerequisites. It is possible to execute any task directly, which entails execution of any of its dependencies. For example, to create an ungrib run directory provisioned with all the files, directories, symlinks, etc. required per the configuration file:
```
$ uw ungrib provisioned_rundir --config-file config.yaml --cycle 2021-04-01T12 --batch
```

Specifying the --show-schema flag, with no other options, prints the driver’s schema:

uw ungrib --show-schema >schema
head -n20 schema

{
  "$defs": {
    "iso8601": {
      "pattern": "^[0-9]{4}-[0-9]{2}-[0-9]{2}[T ][0-9]{2}:[0-9]{2}:[0-9]{2}$",
      "type": [
        "datetime",
        "string"
      ]
    }
  },
  "properties": {
    "ungrib": {
      "additionalProperties": false,
      "properties": {
        "execution": {
          "additionalProperties": false,
          "properties": {
            "batchargs": {
              "additionalProperties": true,
              "properties": {

Use the --schema-file option to specify a custom JSON Schema file with which to validate the driver config. A custom schema could range in complexity from the simplest, most permissive schema, {}, to one based on the internal schema shown by --show-schema.

ungrib

Examples

`ungrib`