METplus Use Case: QPF Ensemble
The QPF Ensemble use case utilizes the MET Pcp-Combine and Grid-Stat tools. This tutorial does not cover a use case that utilizes Ensemble-Stat. However, there are use case configuration files that do in the METplus repository here: https://github.com/NCAR/METplus/tree/master_v2.2/parm/use_cases/ensemble.
Optional: Refer to the MET Users Guide for a description of the MET tools used in this use case.
Optional: Refer to A-Z Config Glossary section of the METplus Users Guide for a reference to METplus variables used in this use case.
Setup
Create Custom Configuration File
Define a unique directory under output that you will use for this use case. Create a configuration file to override OUTPUT_BASE to that directory.
Set OUTPUT_BASE to contain a subdirectory specific to the QPF Ensemble use case. Make sure to put it under the [dir] section.
OUTPUT_BASE = {ENV[METPLUS_TUTORIAL_DIR]}/output/qpf-ensemble
Using this custom configuration file and the QPF use case configuration files that are distributed with METplus, you should be able to run the use case using the sample input data set without any other changes.
Review Use Case Configuration File
Open the file and look at all of the configuration variables that are defined.
Note that variables in hrefmean-vs-mrms-qpe.conf reference other config variables that have been defined in other configuration files. For example:
This references INPUT_BASE which is set in the METplus data configuration file (metplus_config/metplus_data.conf). METplus config variables can reference other config variables even if they are defined in a config file that is read afterwards.
Run METplus
Run the following command:
The will run Pcp-Combine to build a 6-hour forecast accumulation and then run Grid-Stat to compare it to a 6-hour observation accumulation. METplus is finished running when control returns to your terminal console and you see the following text:
Review the Output Files
You should have output files in the following directories:
- grid_stat_MEAN_HREF_MEAN_APCP_vs_MRMS_QPE_P06M_NONE_A06_000000L_20170622_000000V_eclv.txt
- grid_stat_MEAN_HREF_MEAN_APCP_vs_MRMS_QPE_P06M_NONE_A06_000000L_20170622_000000V_grad.txt
- grid_stat_MEAN_HREF_MEAN_APCP_vs_MRMS_QPE_P06M_NONE_A06_000000L_20170622_000000V.stat
Take a look at some of the files to see what was generated.
Review the Log Files
Log files for this run are found in $METPLUS_TUTORIAL_DIR/output/qpf-ensemble/logs. The filename contains a timestamp of the current day.
NOTE: If you ran METplus on a different day than today, the log file will correspond to the day you ran. Remove the date command and replace it with the date you ran if that is the case.
Review the Final Configuration File
The final configuration file is metplus_final.conf. It is found in the top level directory of your OUTPUT_BASE. This contains all of the configuration variables used in the run.
