WRF Release Information

Latest Releases

The latest WRF system major release is Version 3.9 (April 2017), and details on it may be found at WRF V3.9 Model Updates and WRF/WPS/WRFDA Downloads.  Some of V3.9's major improvements are as follows.

  • Dynamics: Hybrid vertical coordinate
  • Software: Physics suite selection mechanism, OpenMP updates, WENO advection speedups
  • Physics: New P3 microphysics scheme, updated Grell-Freitas cumulus scheme, NSSL microphysics updates, Noah-MP LSM coupled with urban models, updates to Thompson aerosol-aware microphysics scheme, and new LSM datasets (crop, groundwater, albedo)
  • WRFDA: 4D-EnVar capability, AMSR2 cloudy radiance obs assimilation, null-echo radar obs assimilation, updated CRTM (V2.2.3)
  • WRF-Chem: New TUV photolysis scheme, wet removal in MOZCART
  • WRF-Hydro: Multiple time scale capability, new level pool scheme, new bucket model, netcdf output for baseflow bucket model
  • HWRF: Addition of 2016 operational system changes, new scale-aware SAS scheme, idealized TC capability

The most recent WRF releases are minor releases V3.9.1 and V3.9.1.1.  These were issued in August 2017 and among other things provided a revised version of WPS and bugfixes to V3.9.

  • WRF-Chem: Added RACM_SOA_VBS_AQCHEM_KPP chemical mechanism to the call to the optical driver in order to calculate/output aerosol optical properties.

Upcoming Release— WRF V4.0

The next major WRF release will be Version 4.0 and is targeted for late Spring 2018. It will not be backward-compatible with all components of previous versions.  Version 4.0 will have the hybrid vertical coordinate as the default, and a list of candidate features for the release is given below.  As always, the ultimate inclusion of any candidate item is dependent on its timely preparation and acceptance.

  • Software: Hybrid vertical coordinate as default, shared physics schemes with MPAS, stochastic optimization of 2D forcing, full theta-m implementation, outputting of total fields as diagnostics, default compression and netCDF4
  • WRF-Chem: New heterogeneous gas chemistry option, diagnostics in radiation driver, new MOZART scheme
  • HWRF: 2017 operational configuration, updated schemes: Ferrier-Aligo microphysics, scale-aware SAS cumulus, Grell-Freitas cumulus
  • WRFDA: GOES imager radiance data assimilation, large-scale analysis constraint, divergence constraint, WRFPlus Chem and WRFDA Chem
  • LSM: Expanded soil data information, new crop model 
  • WRF-Hydro: Merger of Nat'l Water Center code into repository
  • Physics: Upgraded Goddard radiation and microphysics schemes, updated CLM4 land surface package

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 testing preparation and documentation requirements, and adhering to the release schedule. Prospective contributors may write to wrfhelp@ucar.edu 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). Both the Developers' Committee and the Release Committee are described in WRF Code Repository and Release Administration.

Timeline— 2018 WRF Major Release

The timeline for the next major WRF release, scheduled for late Spring 2018, is as follows. "RC" refers to the Release Committee; "DC" refers to the Developers' Committee.

September 2017

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

February 2018

Code accepted and admitted to the repository is eligible (but not guaranteed) to be included in the release. Code submissions must undergo all preliminary testing and acceptance by this time in order to be considered for the release. A release branch of the code designated and becomes the basis for the release code. While the WRF repository will remain open to submissions after this time (as the repository is open throughout the year), new additions will not be eligible for the release branch.

March-April 2018

Release code testing and first friendly-use release

  • Only bugfixes for preliminary release code permitted.
  • WRF repository remains open for code additions, which may be considered for releases after the 2017 major release.
  • First friendly-user release— preliminary code made available for testing.

April-May 2018

Continued release code testing and second friendly-use release

  • Remaining bug fixes implemented.
  • Full set of regression tests run on machines at NCAR.

May 2018

  • Final round of troubleshooting and large testing.
  • RC and DC meetings focus on remaining code needs and testing. Final necessary prepration and commit schedule determined.

Late May/Early June 2018

  • DC certifies code (final approval) for release. Code packaged and staged for release.
  • Release and notification to WRF users.

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 are listed below.

Jordan Powers, NCAR/MMM— Chairman
Ravan Ahmadov, NOAA/ESRL
Michael Barlage, NCAR/RAL
Laurie Carson, DTC
Jimy Dudhia, NCAR/MMM
Dave Gill, NCAR/MMM
Jake Liu, NCAR/MMM
Wei Wang, NCAR/MMM