WRF Release Information

Latest Release— WRF V4.2.2

The WRF model has been updated to Version 4.2.2 on January 15, 2021. This is a bug fix release. Following are fixes associated with this release:

  • Compiling
  • Dynamics
  • Physics
  • Data Assimilation
  • Chemistry
  • Diagnostics
  • Registry
  • Miscellaneous

Visit the WRF Model GitHub releases page for more information

Release— WRF V4.1

The latest WRF system major release is Version 4.1 (April 2019).  While details on it may be found at WRF V4.1: Updates and WRF Downloads, some of V4.1's improvements are as follows.

  • Dynamics: Hybrid vertical coordinate previously introduced as an option now the WRF default coordinate. Theta-m prognostic temperature variable now the default.
  • Software: Default build now netCDF4 with compression, if netCDF4 is built with the HDF5 library. Capability added to determine x- and y-direction computational patch sizes based on the full domain size and the number of MPI ranks used to guard against too-small patches (<10 grid cells).
  • Physics: P3 microphysics: Added option for including a second free array for ice. Thompson-Eidhammer microphysics: Added surface dust emissions scheme to link with the ice-friendly aerosol variable. KSAS cumulus scheme, a scale-aware version of NSAS, added. MYNN PBL and MYNN surface layer schemes: Enhancements of mass-flux scheme and of mixing length and stratus component of subgrid clouds. RUC LSM: Changed empirical formulation of frozen precipitation density to better match observed snow accumulation on the ground and now apply snow mosaic approach only when temperature at the first atmospheric level is >271K.
  • Program Real: New option to compute vertical level distribution, offering a smooth variation of dz.
  • WRFDA: RTTOV and CRTM interfaces upgraded to latest versions. Himawari-AHI radiance observations added.
  • HWRF: Addition of 2018 operational system modifications.

Fixes for issues identified in V4.1 will be provided via WRF minor releases in the WRF repository on Github.

Future Release— WRF V4.2

The next major WRF release will be Version 4.2 and is targeted for Spring 2020.  A list of candidate features will be posted after the release preparation begins and will appear here in Fall 2020. 

  • Software: Resolution of reported issues in V4.1.
  • Physics: Resolution of reported issues in V4.1.

Developers seeking to propose code for new or improved capabilities for the WRF system must review Information for Code Contributors. The consideration of any code for inclusion in the WRF repository or a release depends on the developer's following the physics review procedures, meeting code testing and documentation requirements, and adhering to the release schedule. Prospective contributors may post to the WRF & MPAS-A Support Forum http://forum.mmm.ucar.edu/phpBB3/ for information and for contacting the Developers' Committee (which oversees WRF contributions and manages the repository) or the Release Committee (which oversees the major release process). The WRF Developers' Committee and the WRF Release Committee are described in WRF Code Repository and Release Administration.


2020 WRF Major Release Timeline

The general timeline for the next major WRF release, Version 4.2, scheduled for Spring 2020, is as follows. "RC" refers to the Release Committee; "DC" refers to the Developers' Committee.

September 2019

  • RC begins meetings for major release cycle.
  • Initial release picture compiled.

January 2020

  • Code accepted and admitted to the repository is eligible to be included in the release. A release branch of the repository code is designated. While the WRF repository will remain open to new submissions, such additions will not be eligible for the release branch.

February-March 2020

  • Release code testing and friendly-user releases: preliminary code made available to developers/users.
  • Only bugfixes for release code permitted.
  • WRF repository remains open for code additions, which may be considered for releases after the major release.

March-April 2020

  • Continued release code testing by friendly users.
  • Full set of regression tests run at NCAR.

April 2020

  • RC and DC meetings focus on remaining code needs and testing issues. Final round of large testing and code commits.
  • DC certifies code for release.
  • Release of V4.2 and user notification.

Release Committee

The WRF Release Committee oversees the major releases of WRF. It is described in the policies for NCAR's administration of the WRF code in WRF Code Repository and Release Administration. The members for the V4.1 release cycle are listed below.

Jordan Powers, NCAR/MMM— Chairman
Ravan Ahmadov, NOAA/ESRL
Michael Barlage, NCAR/RAL
Laurie Carson, DTC
Ming Chen, NCAR/MMM
Jimy Dudhia, NCAR/MMM
Jerome Fast, PNNL
Katelyn FitzGerald, NCAR/RAL
Brian Gaudet, PNNL
Dave Gill, NCAR/MMM
Jake Liu, NCAR/MMM
Wei Wang, NCAR/MMM
Kelly Werner, NCAR/MMM