WRF-NMM Users Page

WRF Modeling System Updates

The WRF model tar file has been updated to Version 3.3 on April 6, 2011.

The WRF Pre-Processing System (WPS) has also been upgraded to Version 3.3.

WRF Version 3.3 new features, updates and bug fixes

WRF-NMM specific updates

  • Added DFI capability
  • Changed the default advection scheme to a newer, highly conservative option in the namelist.input (euler_adv=.true.). Note: This option only works with the Ferrier/Eta microphysics schemes. If you run with a different microphysics scheme you will need to change the advection scheme in your namelist.input (euler_adv=.false.).
  • Moved parameters controlling the strength of diffusion (coac) and divergence damping (codamp) from the code to the namelist.input file for easier adjustments
  • Modification made to the nonhydrostatic dynamics
  • Fixed ingest of binary WPS data into real_nmm
  • Other miscellaneous bug fixes

HWRF specific updates

  • Established 2011 opertional baseline capability
  • Improved computational performance
  • Updated surface fluxes
  • Revised coupler interface (to include HYCOM in addition to POM). Note: This change requires an update to the WPP Makefile which is described here.
  • Limit GWD computations to the parent only
  • Added real_nmm capability to read input files from a "prep-hybrid" preprocessor (used operationally to ingest spectral GFS data for IC/BC)
  • Added preliminary development for third moving nest capability
  • Added alternate experimental tracking algorithm for moving nest
  • Miscellaneous bug fixes

General updates


  • NEW:
    • A new trigger function based on Ma and Tan (2009, Atmospheric Research) is added to Kain-Fritsch scheme. The new trigger tends to trigger less convection in weakly forced environment.
  • Radiation:
    • RRTMG longwave: Improvement for temperature in stratosphere. This is similar to the improvement put in RRTM in V3.2. Reinstall fixes for clear-sky in v3.2 with consistant data files.
  • Microphysics:
    • Thompson microphysics: bug fix and updates (see notes released on 12/13/2010)
    • WDM5, WDM6: minor fixes
    • Eta scheme: allow for interaction with cumulus detrained cloud
  • Cumulus:
    • GD cumulus: minor fix for vertical shear calculation
  • Planetary Boundary Layer:
    • MYJ: TKE_MYJ and EL_MYJ are renamed to TKE_PBL and EL_PBL
  • Surface Physics:
    • Noah LSM: allow seasonal roughness length changes, fix underground run-off.
    • LANDUSE.TBL: correct some categories in MODIS part.


  • I/O associated with restart: there were a couple of problems / issues as a result of V3.2 updates:
    1. output frequencies for history (wrfout) and restart (wrfrst) after restart: if one would make the frequency longer, the first output it would write would have used the old frequency. This is due to the I/O alarms written to wrfrst file. This can be corrected by using namelist 'override_restart_timers = .true.' in &time_control
      • Care must be taken when using namelist 'override_restart_timers'. If you use fdda and sst_update, and if you restart at a time which is not a data time, then the restart run could be wrong because it may use the wrong data for fdda and sst_update.
    2. there is not a wrfout file at the start of a restart run - this is not an error, it is just a different behaviour from the new restart. Output can be forced by using namelist option 'write_restart_at_0h = .true.'.


  • p-netCDF support for io quilting (contributed by Porter of Daresbury Lab, UK)
  • Improved error messages when using runtime I/O