WRF_FCST_OSSE

A WRF-Based forecast system for OSSEs. Loosely based on HRRRv4.

Contents

• bin: Scripts used to run the various forecast system components (e.g., preprocesser, DA, forecast model, postprocessor).
• env: Lua files specifying the runtime environment on various HPC systems.
• exec: Directory holding executables. Currently empty except for a README describing the necessary executables.
• static: Subset of the static files needed to run the WRF_FCST_OSSE. Mainly just includes namelist files. Additional static files need to be downloaded.
• xml: Rocoto workflow for the forecast system

Running WRF_FCST_OSSE

All development is currently being done on Hercules. No other NOAA RDHPCS systems have been tested.

Steps to run WRF_FCST_OSSE:

1. Clone WRF_FCST_OSSE: git clone --recursive https://github.com/ShawnMurdzek-NOAA/WRF_FCST_OSSE.git.
2. cd WRF_FCST_OSSE.
3. If necessary, edit the top portion of setup_exp.sh so it has the correct machine and season.
4. Run setup_exp.sh, which does the following:
   1. Link necessary executables in exec. See exec/README.md for a list of necessary executables.
   2. Update environment lua files in env to match the environments used to compile the executables in exec.
   3. Download the additional static files. See static/README.md for additional information.
   4. Link static/GSI_HRRR or static/GSI_RRFS to static/GSI.
   5. Create empty run, log, and loghistory directories (on the same level as bin, env, etc.).
   6. Within run, create a subdirectory called surface and add surface data from a previous HRRR run to initialize the soil state. File naming convention is wrfout_sfc_HH, where HH is the hour.
5. Update the upper portion of xml/HRRR_retro.xml.<machine> to have the correct machine, directories, etc.
6. Link xml/HRRR_retro.xml.<machine> to xml/HRRR_retro.xml.
7. Run the workflow using xml/run_hrrr_retro.ksh.
8. NOTE: To start the initial spinup cycle, the wrf_arw_short, wrf_arw_long, and HRRR_soilsave_01 tasks for all initialization hours for that spinup period (i.e., 03-08 or 15-20 UTC) must be manually completed, because these tasks are dependencies for the gsi_hyb_spinup task.

Running a continuously cycled experiment

The instructions listed above are for a partially cycled experiment. To run a continuously cycled experiment, follow the same steps as for a partially cycled experiment, but change the times in the <cycledef></cycledef> tags so that the workflow only runs for 9-12 hours. This is needed to spin up the continuously cycled experiment. Once that spinup time has passed, use the xml/HRRR_retro.xml.<machine>.continuous file to run the rest of the experiment.

Input Data Formatting

Input data for WRF_FCST_OSSE should follow these naming conventions (first part of each path is defined in xml/HRRR_retro.xml):

• Conventional observations (prepBUFR format): OBS_DIR/YYYYMMDDHH.rap.tHHz.prepbufr.tm00
• Sea surface temperature analyses (GRIB2 format): SST_DIR/YYJJJHH000000
• GFS forecasts for ICs and LBCs (GRIB2 format): GFS_DIR/YYJJJHH0000FF
• GDAS forecasts for flow-dependent background error covariances (HDF5 format): ENKFFCST_DIR/YYJJJJHH00.gdas.tHHz.atmf0FF.memMMM.nc
• Commercial aircraft observation reject list (ASCII format): AIRCRAFT_REJECT/YYYYMMDD_rejects.txt
• Mesonet observation uselist (ASCII format): SFCOBS_USELIST/YYYY-MM-DD_meso_uselist.txt
• Snow and ice analyses (GRIB2 format): NCEPSNOW_DIR/YYJJJHH00000000

where...

• YYYY: 4-digit year (valid time for obs, init time for models)
• MM: 2-digit month (valid time for obs, init time for models)
• DD: 2-digit day (valid time for obs, init time for models)
• JJJ: 3-digit Julian day (valid time for obs, init time for models)
• HH: 2-digit hour (valid time for obs, init time for models)
• FF: 2-digit forecast hour
• MMM: 3-digit ensemble member number

Notes

In order to run WRF_FCST_OSSE, the following directories are also needed:

• log: An empty directory for WRF_FCST_OSSE logs.
• loghistory: An empty directory for WRF_FCST_OSSE logs.
• run: A mostly empty directory for WRF_FCST_OSSE output. Only output needed to start a forecast run is surface data (see "Steps to run WRF_FCST_OSSE" above).

Selecting a GSI Version

Two sets of GSI static files are provided: static/GSI_HRRR and static/GSI_RRFS. These include some of the input static files for running GSI using the HRRRv4-era version of GSI and the RRFS(FV3)-era of GSI. Choose the appropriate directory, then link it to the static/GSI directory (e.g., ln -sf GSI_HRRR GSI).