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

Phyiscs:

• 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:

• 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.'.

Software:

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