/** @namespace scripts
@brief High-level logic of the HWRF Python scripts.

@section scripting_layer Scripting Layer

The scripts package contains the high-level logic of the HWRF
system.  These are command line executable scripts that can be run
manually, or by the workflow layer (such as the wrappers, Rocoto or
the J-Jobs via ecFlow).  Their job is to pass control on to the hwrf
and pom packages to actually do the work of running the HWRF system.

Generally, these are all simple Python scripts which load the
hwrf_expt module, import some of its objects and tell them to
execute part of the workflow.  All of these scripts will log an
initial message and a final success or failure message to the main
log stream, the jlogfile.

Most of the Python scripts in this directory follow a standard
pattern:
  1. Initialize the produtil.setup and hwrf_expt Python modules.
  2. Log a message to the produtil.log.jlogger saying that the
     script is starting.
  3. Import one or more hwrf.hwrftask.HWRFTask objects and call
     their run() methods.
  4. Log a message to the produtil.log.jlogger saying the script has
     succeeded or failed.

The actual logic of how to run the HWRF system is in the hwrf
package, and the connections between the various HWRF components is
made in the hwrf_expt module, and its various helper modules (such
as hwrf.init and hwrf.hwrfsystem).

In some cases, the Scripting Layer has to do significant extra
processing in order to glue everything together.  For example, the
exhwrf_output has to copy many Tasks' outputs to the COM directory
or elsewhere.  The exhwrf_post has to run several Tasks at the same
time and does so with a sophisticated loop.  The exhwrf_products has
a similar problem which it solves by running multiple scripts at the
same time in different MPI ranks.

@section script_overview Scripting Layer Contents

This section describes the relationships between the various
scripts, and references useful pages of documentation.  Pages in
parentheses are hwrf and pom package documentation.

@subsection launcher_scripts HWRF Launching Script

There is one script that must be run first:

* exhwrf_launch --- sets up the workflow for a particular forecast cycle

That launcher job creates the directory structure, database files
and other critical initial files needed by the HWRF system.  It will
also run sanity checks to see if the system will be able to run the
requested configuration.

@subsection pulling_pushing Data Pulling/Pushing Scripts

These scripts pull data from tape or over the internet to serve as
input to the HWRF, or they push the data to tape for storage.  This
is needed because a full-scale test of the HWRF system cannot
generally fit on disk.  The needed input from four years of GFS,
GDAS and GFS ENKF runs also will not fit on disk.  Instead, it is
placed on tape, and pulled to disk as needed.

* exhwrf_input --- pulls data for input (hwrf.input) to HWRF
* exhwrf_bufrprep --- turns data tanks into bufr files for
  exhwrf_gsi's consumption (hwrf.bufrprep, hwrf.gsi)
* exhwrf_para_archive --- pushes data to tape after HWRF has finished
* exhwrf_wrfout_archive --- special extra archiving job for native wrfout files

@subsection initialization_scripts Initialization Scripts

After the parent model and observational data has been pulled from
tape (or wherever) it must then be processed to create initial and
boundary conditions.  Here are the initialization jobs in
approximate order they appear in the workflow:

* exhwrf_ocean_init --- generates ocean initial and boundary
  conditions (hwrf.mpipomtc, pom) from data pulled by the
  exhwrf_input script.

* exhwrf_init --- spectral processing (hwrf.prep), interpolation and
  creation of wrfanl, ghost, wrfinput, wrfbdy and other input files
  (hwrf.fcsttask) from inputs obtained by the exhwrf_input script.
  The high-level description of this workflow is created in the
  hwrf.init module.

* exhwrf_relocate --- takes input from the exhwrf_init job, and
  relocates the vortex, resizing it and changing its intensity if
  needed (hwrf.relocate)

* exhwrf_gsi --- runs the GSI data assimilation system (hwrf.gsi) on
  the relocated vortex

* exhwrf_merge --- merges (hwrf.relocate) the relocated vortex and
  GSI output to create the final input to WRF

@subsection forecast_scripts Forecast and Post-Processing

After the initial and boundary conditions are available, the
forecast starts, and its output must be converted to forms usable by
forecasters.

* exhwrf_gsi_post --- post-processes (hwrf.gsipost, hwrf.hwrfsystem)
  the inputs and outputs of GSI (hwrf.gsi) to create lat-lon GRIB2
  files suitable for study.  This is for examining the effect of
  data assimilation on the input conditions to the forecast.

* exhwrf_forecast --- runs the full-length forecast, either with
  (hwrf.mpipomtc.WRFCoupledPOM) or without (hwrf.fcsttask.WRFAtmos)
  ocean coupling.  Takes inputs from the exhwrf_ocean_init,
  exhwrf_init, exhwrf_relocate and exhwrf_merge jobs.

* exhwrf_unpost --- deletes the output of the exhwrf_post,
  exhwrf_products and some of exhwrf_output, allowing the
  post-processing to be redone.

* exhwrf_post --- runs the Unified Post Processor (hwrf.post,
  hwrf.hwrfsystem) on the output of the exhwrf_forecast to create
  native grid GRIB files.

* exhwrf_products --- runs GRIB regridding utilities (hwrf.gribtask,
  hwrf.regrib) on the output of the exhwrf_post to create lat-lon
  GRIB2 output files suitable for use by forecasters.  Runs the GFDL
  vortex tracker (hwrf.tracker) to create a hurricane track file

* exhwrf_output --- delivers the output of the exhwrf_products and
  exhwrf_forecast to their destination.  In the operational HWRF,
  this job also emails the NOAA Senior Duty Meteorologist the AFOS
  file, which contains the HWRF track.

@subsection scripts_ensda Data Assimilation Ensemble 

The HWRF system is capable of running a 6hr forecast ensemble based
on the output of the GFS ENKF.  The output of this ensemble is fed
into the next HWRF cycle's exhwrf_gsi to be used by hwrf.gsi for
generating forecast error covariances.

* exhwrf_ensda_pre --- determines if the ensemble should be run

* exhwrf_ensda --- runs one member of the forecast ensemble (hwrf.ensda)

* exhwrf_ensda_output --- checks to see if the exhwrf_ensda scripts
  all completed
*/