MET Online Tutorial for METv8.0 | Grid-Stat > Run

Next, we'll run Grid-Stat twice on the command line using the following two commands:

With the bootstrap confidence intervals turned off (in boot dictionary, n_rep = 0;), these Grid-Stat commands should run very quickly - in a matter of seconds.

In the first command, which verifies a precipitation forecast, Grid-Stat performs 28 verification tasks. The 28 tasks are a result of: (1 field (APCP at 12-hours) * 4 masking regions) + (1 field * 2 neighborhood sizes * 3 raw thresholds * 4 masking regions)

In the second command, which verifies a probability of precipitation forecast, Grid-Stat performs only 4 verification tasks. The 4 tasks are a result of: (1 field (APCP at 12-hours) * 4 masking regions). Note that the neighborhood verification methods are not applied to probability forecasts.

In general, the MET tools check the output flag values to determine which verification methods to apply. Only those methods required to produce the output statistics requested are performed.

The output file names from these two commands are of the form:

• For the first command:

• For the second command:

Note how similar these output filenames are. Since they're both verified against the same observation file, the valid times listed (20050808_000000V) are the same. The only difference is in the forecast lead times, 24 hours for the first command and 108 hours for the second command. If you'd like to differentiate these output file names in a more descriptive way, you could set the output_prefix parameter in the configuration files. For example, setting the output_prefix parameter to APCP in the first configuration file and POP in the second configuration file would result in the following naming conventions:

The output_prefix configuration option may be used to generate unique output file names.