Introduction

The WRF Data Assimilation system (WRFDA) is a community data assimilation system for the Weather Research and Forecasting model. It is a community system in the sense that the model is kept open-source and released in the public domain. WRFDA currently has support for 3DVAR, 4DVAR, ETKF, and Hybrid ensemble/variational methods of data assimilation, and is undergoing constant improvements and additions. The system is maintained by the WRFDA Group of the Mesoscale and Microscale Meteorology (MMM; pronounced "em cubed") Laboratory of the National Center for Atmospheric Research (NCAR). However, we are constantly incorporating improvements proposed and designed by community users as well.

In addition to being open-source and public domain, WRFDA is designed and maintained to be as flexible as possible, keeping within the goals of the WRF model to be flexible for a wide range of uses (e.g. research, theory, modeling, and operational) and run on a wide range of platforms (e.g. several supported compilers, on single or multiple processors, on systems ranging from Mac/Linux PCs to the largest supercomputers, including NCAR's own Yellowstone).

The WRFDA system and its history are summarized in detail in the following journal article: Barker, D., X.-Y. Huang, Z. Liu, T. Auligné, X. Zhang, S. Rugg, R. Ajjaji, A. Bourgeois, J. Bray, Y. Chen, M. Demirtas, Y.-R. Guo, T. Henderson, W. Huang, H.-C. Lin, J. Michalakes, S. Rizvi, and X. Zhang, 2012: The Weather Research and Forecasting Model's Community Variational/Ensemble Data Assimilation System: WRFDA. Bull. Amer. Meteor. Soc., 93, 831–843.

• perl 5.04 or later
• netCDF libraries
• MPI libraries, if parallel runs are desired
• GNU zip (gzip), a free file-compression utility
• The following UNIX utilities: csh and Bourne shell, tar, make, M4, sed, awk, and the uname command
  

Note: WRFDA does not yet support netCDF4 features such as HDF5, and may fail if netCDF4 libraries are used. To avoid this problem, either install netCDF version 3.6.3 or earlier (not recommended) or configure a more recent version of netCDF with the option "--disable-netcdf-4". See the "netCDF Help Page" for more information.

Users' Guide
This Online Tutorial is complementary to the Users' Guide. The latest WRFDA, WRF and WPS codes are described in this document. Chapter 6 covers WRFDA specifically. The Users' Guide is updated for every Bi-Annual WRF Tutorial (typically January and July), in addition to every major release (typically in April), thus it is the most up-to-date guide for running WRFDA. It is highly recommended to download this guide before you start running the model.

Annual Tutorial Presentations
All the slide shows presented at the last Annual Tutorial Class, held at the NCAR Foothills Laboratory in Boulder, Colorado, USA.

Note: This website is currently under construction. If you notice any problems with the website, including but not limited to broken links, formatting errors, or incorrect information, please submit an email to the or wrfhelp@ucar.edu so that we can address the problem. We appreciate your feedback!

Getting started

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