METplus Practical Session Guide (Version 5.0) | Session 5: MODE and MTD > MET Tool: MODE

MODE Tool: General

MODE Functionality

MODE, the Method for Object-Based Diagnostic Evaluation, provides an object-based verification for comparing gridded forecasts to gridded observations. MODE may be used in a generalized way to compare any two fields containing data from which objects may be well defined. It has most commonly been applied to precipitation fields and radar reflectivity. The steps performed in MODE consist of:

  • Define objects in the forecast and observation fields based on user-defined parameters.
  • Compute attributes for each of those objects: such as area, centroid, axis angle, and intensity.
  • For each forecast/observation object pair, compute differences between their attributes: such as area ratio, centroid distance, angle difference, and intensity ratio.
  • Use fuzzy logic to compute a total interest value for each forecast/observation object pair based on user-defined weights.
  • Based on the computed interest values, match objects across fields and merge objects within the same field.
  • Write output statistics summarizing the characteristics of the single objects, the pairs of objects, and the matched/merged objects.

MODE may be configured to use a few different sets of logic with which to perform matching and merging. In this tutorial, we'll use the most simple approach, but users are encouraged to read Chapter 14 of the MET User's Guide for a more thorough description of MODE's capabilities.

MODE Usage

View the usage statement for MODE by simply typing the following:
Usage: mode  
  fcst_file Input gridded forecast file containing the field to be verified
  obs_file Input gridded observation file containing the verifying field
  config_file MODEConfig file containing the desired configuration settings
  [-config_merge merge_config_file] Overrides the default fuzzy engine settings for merging within the fcst/obs fields (optional).
  [-outdir path] Overrides the default output directory (optional).
  [-log file] Outputs log messages to the specified file
  [-v level] Level of logging
  [-compress level] NetCDF compression level
The forecast and observation fields must be on the same grid. You can use copygb to regrid GRIB1 files, wgrib2 to regrid GRIB2 files, or use the automated regridding functionality within the MET config files.
The MODE tool usage statement also has instructions for verifying multivariables. These are the same as the MODE usage, only passing ASCII lists that contain multiple files instead of a single file.

At a minimum, the input gridded fcst_file, the input gridded obs_file, and the configuration config_file must be passed in on the command line.