Foreword

This User’s Guide describes the Advanced Research WRF (ARW) Version 2.2 modeling system, released in December 2006, and updated in November 2007. As the ARW is developed further, this document will be continuously enhanced and updated.

This version contains the documentation for the new WRF Preprocessing System (WPS), which replaces the old WRFSI system. The documentation for the WRFSI system is retained as Appendix A of this document. New documentation for the post-processing software NCL and ARWpost have been included. All functions and procedures under WRF_NCL have moved in under the NCL libraries. The ARWpost package replaces WRF2GrADS and WRF2VIS5D. Documentation for the old post-processing programs is retained in Appendix B.

Highlights of changes to WRFV2 include:

• New physics options: CAM radiation, Thompson microphysics, and urban canopy model coupled with Noah;
• Positive-definite advection for moisture, scalars, tke and chemical variables;
• Sixth order horizontal numerical diffusion;
• Vertical interpolation in real to work with WPS data;
• Analysis and observation nudging

For the latest version of this document, please visit the ARW User’s Web site at http://www2.mmm.ucar.edu/wrf/users/.

Please send feedback to wrfhelp@ucar.edu.

Contributors to this guide:

Wei Wang

Dale Barker

John Bray

Cindy Bruyère

Michael Duda

Jimy Dudhia

Dave Gill

John Michalakes