Introduction: General

Introduction

Model Evaluation Tools (MET) is a highly configurable, state-of-the-art suite of verification tools designed for the verification and evaluation of numerical weather forecasts. Although MET was developed at the Developmental Testbed Center (DTC) to be used with the Weather Research and Forecasting (WRF) modeling system, the data formats and standards used allow MET to be run on the output of other modeling systems as well.

The current MET capabilities include traditional verification approaches for standard surface and upper air variables; confidence intervals for all verification measures; and spatial forecast verification methods. The MET package is designed to be modular and flexible. Each tool can be run individually without running the entire set of tools. New tools can easily be added to the MET package due to this modular design.

Future MET development will take into account the needs of the NWP community - including operational centers and the research and development community.

Software Requirements

The following are required to build and run MET:

• C, C++, and Fortran-77 compilers all from the same family (recommend GNU or PGI compilers)
• The UNIX make (GNU make) utility
• NCEP's BUFRLIB for decoding point observations in PrepBufr format
• Unidata's NetCDF library
• The GNU Scientific Library (GSL)
• The F2C (or G2C) library

Additional Recommended Software

Although none of the following utilities are required to run MET, they may be helpful in preparing data for use in MET:

• The WRF Post-Processor for users verifying WRF model data
• The copygb utility for regridding GRIB data
• The cwordsh utility for using PrepBufr data

Program Flow

MET consists of a set of verification tools run from the command line. The current MET tools perform the following verification techniques:

• Compare a gridded forecast to point observations using the PB2NC, ASCII2NC, and the Point-Stat tools.
• Compare a gridded forecast to a gridded analysis field using the PCP-Combine and Grid-Stat tools.
• Apply an object-based verification approach to a gridded forecast and gridded analysis field using the PCP-Combine and MODE tools.
• Aggregate results across many cases using the VSDB-Analysis and MODE-Analysis tools.

Documentation

MET Users Documentation consists of a detailed user's guide, slides from previous tutorials, and related white papers. Users are strongly encouraged to download and read the MET Users Guide before they start using MET.