Foreword

This User’s Guide describes the Advanced Research WRF (ARW) Version 3.7 modeling system, released in April 2015. As the ARW is developed further, this document will be continuously enhanced and updated. Please send feedback to wrfhelp@ucar.edu.

This document is complementary to the ARW Tech Note (http://www.mmm.ucar.edu/wrf/users/docs/arw_v3.pdf), which describes the equations, numerics, boundary conditions, and nesting etc. in greater detail.

Highlights of updates to WRFV3.7 include:

· WRF model:

New physics:

o New Tiedtke cumulus scheme (contributed by Chunxi Zhang of Univ of Hawaii);

o Multi-scale Kain-Fritsch cumulus scheme (contributed by K. Alapaty and J. Herwehe of EPA);

o Shin-Hong scale-dependent PBL scheme (contributed by H. Shin (NCAR) and S-Y Hong of KIAPS, S. Korea);

o A computer-performance optimized version of (contributed by AER and NCEP);

o Radiative-cooling driven top-down mixing option in YSU PBL (contributed by T. Wilson and R. Fovell of UCLA)

o Impervious surface physics in PX LSM (contributed by EPA);

o New urban hydrological processes in single-layer UCM (contributed by J. Yang, Z. Wang of Arizona State University and S. Miao of IUM/CMA, China);

o A new cloud fraction calculation option (contributed by G. Thompson of NCAR).

Others:

o Improved SKEBs (contributed by J. Berner of NCAR);

o Improvement to NoahMP; RUC LSM, NSSL and Mibrandt microphysics;

o 9-sec impervious surface and canopy fraction dataset derived from NLCD (contributed by EPA);

o 9-seconds NLCD2006, 2011 landuse dataset (contributed by EPA).

· WRF-DA updates:

o New background error option CV7;

o Updated radar data assimilation with new options for reflectivity assimilation;

o A new microphysics option is available for 4DVAR;

o Added support for lat-lon map projection.

· WRF-Chemistry

o Improvement on existing code and packages.

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

Contributors to this guide:

Wei Wang, Cindy Bruyère, Michael Duda, Jimy Dudhia, Dave Gill, Michael Kavulich, Kelly Keene, Hui-Chuan Lin, John Michalakes, Syed Rizvi, Xin Zhang, Judith Berner and Kate Fossell

Contributors to WRF-Fire chapter:

Jonathan D. Beezley, Janice L. Coen, and Jan Mandel

Contributors to UPP section:

Hui-Ya Chuang, Nicole McKee, Tricia Slovacek, Jamie Wolff, and Kate Fossell

Special Acknowledgment:

We gratefully acknowledge the late Dr. Thomas T. Warner for his years of research, development, instruction, leadership, and motivation in the field of NWP modeling.