METplus Practical Session Guide (Version 4.0) | Session 2: Grid-to-Obs > MET Tool: PB2NC

IMPORTANT NOTE: If you are returning to the tutorial, you must source the tutorial setup script before running the following instructions. If you are unsure if you have done this step, please navigate to the Verify Environment is Set Correctly page.

PB2NC Tool: General

PB2NC Functionality

The PB2NC tool is used to stratify (i.e. subset) the contents of an input PrepBufr point observation file and reformat it into NetCDF format for use by the Point-Stat or Ensemble-Stat tool. In this session, we will run PB2NC on a PrepBufr point observation file prior to running Point-Stat. Observations may be stratified by variable type, PrepBufr message type, station identifier, a masking region, elevation, report type, vertical level category, quality mark threshold, and level of PrepBufr processing. Stratification is controlled by a configuration file and discussed on the next page.

The PB2NC tool may be run on both PrepBufr and Bufr observation files. As of met-6.1, support for Bufr is limited to files containing embedded tables. Support for Bufr files using external tables will be added in a future release.

For more information about the PrepBufr format, visit:

https://emc.ncep.noaa.gov/emc/pages/infrastructure/bufrlib.php

For information on where to download PrepBufr files, visit:

https://dtcenter.org/community-code/model-evaluation-tools-met/input-data

PB2NC Usage

View the usage statement for PB2NC by simply typing the following:
pb2nc
Usage: pb2nc  
  prepbufr_file input prepbufr path/filename
  netcdf_file output netcdf path/filename
  config_file configuration path/filename
  [-pbfile prepbufr_file] additional input files
  [-valid_beg time] Beginning of valid time window [YYYYMMDD_[HH[MMSS]]]
  [-valid_end time] End of valid time window [YYYYMMDD_[HH[MMSS]]]
  [-nmsg n] Number of PrepBufr messages to process
  [-index] List available observation variables by message type (no output file)
  [-dump path] Dump entire contents of PrepBufr file to directory
  [-obs_var var] Sets the variable list to be saved from input BUFR files
  [-log file] Outputs log messages to the specified file
  [-v level] Level of logging
  [-compression level] NetCDF file compression

At a minimum, the input prepbufr_file, the output netcdf_file, and the configuration config_file must be passed in on the command line. Also, you may use the -pbfile command line argument to run PB2NC using multiple input PrepBufr files, likely adjacent in time.

When running PB2NC on a new dataset, users are advised to run with the -index option to list the observation variables that are present in that file.