MET Online Tutorial

MET Online Tutorial for METv3.0

Point-Stat Tool: Configure

The behavior of Point-Stat is controlled by the contents of the configuration file passed to it on the command line. The default Point-Stat configuration file may be found in the METv3.0/data/config/PointStatConfig_default file. The configuration used by the test script may be found in the METv3.0/scripts/config/PointStatConfig file. Prior to modifying the configuration file, users are advised to make a copy of the default:

    cp data/config/PointStatConfig_default tutorial/config/PointStatConfig_tutorial

Open up the tutorial/config/PointStatConfig_tutorial file for editing with your preferred text editor.

The configurable items for Point-Stat are used to specify how the verification is to be performed. The configurable items include specifications for the following:

  • The forecast fields to be verified at the specified vertical levels.
  • The threshold values to be applied.
  • The matching time window for point observations.
  • The type of point observations to be matched to the forecasts.
  • The areas over which to aggregate statistics - as predefined grids, configurable lat/lon polylines, or individual stations.
  • The confidence interval methods to be used.
  • The interpolation methods to be used.
  • The types of verification methods to be used.

You may find a complete description of the configurable items in the MET Users Guide or in the comments of the configuration file itself. Please take some time to review them.

For this tutorial, we'll configure Point-Stat to verify the model temperature at two vertical levels and winds at the surface. However, Point-Stat may be configured to verify as many or as few model variables as you desire. The sample input forecast file is not on the NCEP Grid 212 domain. However, we'll use the NCEP Grid 212 domain to define a masking region for our data. Edit the tutorial/config/PointStatConfig_tutorial file as follows:

  • Set fcst_field[] = [ "TMP/Z2", "TMP/P750-850", "UGRD/Z10", "VGRD/Z10" ];
    To verify 2-meter temperature, 10-meter winds, and temperature fields between 750hPa and 850hPa.
  • Set obs_field[] = [];
    To use the settings from fcst_field above.
  • Set fcst_thresh[] = [ "gt278 gt283 gt288", "gt278", "ge5.0", "ge5.0" ];
    To indicate the thresholds to be applied to the fields listed above (TMP is in Kelvin and the U and V components of wind are in m/s).
  • Set obs_thresh[]= [];
  • Set fcst_wind_thresh[] = [ "gt0.0", "ge1.0", "ge5.0", "ge8.0" ];
    To indicate that we'd like VL1L2 lines computed using these thresholds on the wind speeds.
  • Set obs_wind_thresh[] = [];
  • Set message_type[] = [ "ADPUPA", "ADPSFC" ];
    To verify using these 2 observation types.
  • Set mask_grid[] = [ "G212" ];
    To accumulate statistics over NCEP Grid 212 domain.
  • Set mask_poly[] = [ "MET_BASE/data/poly/EAST.poly", "MET_BASE/data/poly/WEST.poly" ];
    To accumulate statistics over the regions defined by the EAST and WEST polyline files.
  • Set interp_width[] = [ 1, 5 ];
    To indicate that the forecast values should be interpolated to the observation locations using the nearest neighbor method and by averaging the forecast values over the 5 by 5 box surrounding the observation location.
  • Set output_flag[] = [ 0, 2, 2, 2, 2, 2, 2, 0, 2, 0, 0, 0, 0, 0, 0 ];
    To indicate that the contingency table counts (CTC), contingency table statistics (CTS), multi-category contingency table counts (MCTC), multi-category contingency table statistics (MCTS), continuous statistics (CNT), scalar partial sum (SL1L2), and vector partial sum (VL1L2) line types should be output.

Save and close this file.