MET Version 3.1

What's New?

The majority of the changes for METv3.1 are internal restructuring and streamlining of how MET reads gridded data, which should be transparent to the user. However, there have been several enhancements the typical user may notice. Please refer to the MET User's Guide for more detail on these additions:

Major Upgrades

• Implemented a new data class hierarchy for reading gridded data files to enable future support of additional data formats, such as GRIB2.
• Incorporated a new logger class throughout MET causing all messages printed to the screen to be prefixed with a message type of ERROR, WARNING, or DEBUG(N), where N indicates the debug level (default is 2):
  • 0: Suppress all messages except WARNING and ERROR.
  • 1: List input and output files.
  • 2: List summary processing information.
  • 3: List detailed processing information.
  • 4+: List detailed debugging information.
• Added a -log command line option to all the MET tools to optionally write their output to a log file.
• Changed how MET is storing gridded data from using an integer scale and offset to a double. The integer scale and offset approach used in prior versions of MET caused individual gridded data values to be stored using only five significant digits.
  • Comparing previous versions to METv3.1, users should notice only slight differences in the continuous statistics MET produces (CNTand SL1L2 line types).
  • However, users may notice more significant differences in statistics that are based on defining a threshold. Due to these precision issues, the contingency tables counts and statistics (CTC and CTSline types) MET produces may change significantly in METv3.1.
  • METv3.1 has enhanced precision over earlier versions and more accurately represents the input data and resulting statistical measures.

New Tools

• Added new madis2nc tool to reformat MADIS NetCDF point observation files into a NetCDF format that MET can read. Currently supports METAR and RAOB types of MADIS files with additional MADIS data types to be added in future releases.
• Added new plot_data_plane utility to read any supported gridded data file, select a field from that file, and render it as a PostScript image.

Enhancements to Existing Tools

• Distributed latest set of bug fixes for METv3.0.1.
• Changed the default output directory for the MET statistics tools from MET_BASE/out/tool_name to the current directory.
• Enhanced plot_point_obs by adding a -data_file command line argument to specify the grid on which the points should be plotted. Included detailed DEBUG(4) information about the points being plotted.
• Enhanced stat_analysis to enable job command arguments on the command line to be used in conjunction with a configuration file. Included detailed DEBUG(4) information when deriving wind directions.
• Enhanced wwmca_regrid and wwmca_plot to specify the pixel age when processing the data.
• Enhanced mode to perform the convolution step more quickly.
• When using MET statistics tools (like grid_stat, point_stat, wavelet_stat, ensemble_stat, and mode) to verify the NetCDF output of other MET tools (like pcp_combine and ensemble_stat), added logic to look for the name and level NetCDF variable attributes. If present, write those values out into the FCST_VAR, OBS_VAR, FCST_LEV or OBS_LEV statistical output columns.
• In the mode_analysis -summary job, modified the computation of the standard deviations by dividing by N-1 rather than N which will have a slight impact on the output.

Enhancement to the Build Process

• Modified the configuration and build process for MET by grouping the parameters that the user needs to edit into a file named user_defs.mk in the top-level MET directory.
• Reorganized the MET directory structure to use src, include, and lib sub-directories for the source code, headers, and compiled libraries, respectively.