The WRF model tar file has been updated to Version 3.5.1 on September 23, 2013. In order to upgrade to version 3.5.1, users can obtain a new copy of the code from the download page.

The WRF Pre-Processing System (WPS) has also been upgraded to Version 3.5.1.

Note: WRF V3.5 and V3.5.1 can use WRFV3 wrfinput and wrfbdy only if iso_temp is set to 0 K in namelist &dynamics. If this option already used, please leave it in. This is important as the default value for iso_temp has been changed from 0 to 200 K in V3.5. Rerunning the new programs is always recommended. Be cautious when using new options.

Also see 'Known Problems' in this release. If you are interested in seeing how V3 has been tested, click here.

WRF Version 3.5.1 improvements and bug fixes

General Updates

Physics Updates
Land surface models and surface layer physics:

• CLM4: fix for 2 m water vapor diagnostics; fix for use of this option with CAM radiation option
• RUC LSM: improved 2 m Qv
• Noah: fix for a sudden jump in 2 m Qv due to abrupt change in exchange coefficient
• Noah-MP: correct a problem with warm air or warm soil temp on permanent ice grid point. MPTABLE.TBL is updated to make stem area index (SAI) consistent with leaf area index (LAI). This could result some improvement in simulated surface temp (e.g., over cropland).
• Surface layer physics option 1 and 11 (MM5 scheme): re-coded Garratt formula; the formula gives nearly identical results (Thanks to B. Green of PSU)
• Surface layer physics option 11 (revised MM5 scheme): match Donelan formula for drag coefficient to that in option 1
• Extend fractional seaice option to QNSE surface layer scheme (Thanks to E. Tastula of Univ of Southern Florida)
• MYNN surface layer option: improved 2 m temp in unstable regime

Deep and shallow cumulus options:

• Grell-Freitas ensemble scheme: fixes and improvements
• NSAS (cu_physics=14): fix for shallow ice clouds
• Tiedtke: index fix (no impact)
• Global/Regional Integrated Modeling System (GRIMS) shallow scheme: reduced mixing

PBL options:

• ACM2 PBL: scheme is now coupled with WRF-Chem
• YSU PBL: now prevents large negative Ri in unstable regime (which could potentially cause model blowup over high terrain)
• TEMF: fix for surface heat and moisture conservation, robustness improvement, and code clean-up
• MYNN PBL: added a new fog scheme provided by Genki Katata of Japan, which is controlled by option grav_settling = 2

Microphysics:

• Thompson: coupling to RRTMG radiation scheme and modifying cloud optical path to use information from Thompson scheme. There is no switch for this change, and it is the default behavior if these options are used together.
• Morrison:
  • Added output for snow+cloud ice and graupel time step and accumulated surface precipitation
  • Bug fix to option without graupel/hail (IGRAUP = 1), include PRACI, PGSACW, and PGRACS as sources for snow instead of graupel/hail (bug reported by Hailong Wang, PNNL)
  • Minor fix to immersion freezing rate formulation (negligible impact)
  • Clarifications to code comments
  • Minor change to shedding of rain, remove limit so that the number of collected drops can smaller than number of shed drops
  • Change of specific heat of liquid water from 4218 to 4187 J/kg/K
  Radiation:
  • Interpolation of short-wave radiation added based on the updated solar zenith angle between SW calls. It must be activated in the namelist with the new physics option swint_opt. This option is being included as a global attribute of the wrfout, so the user knows whether it was used or not. This change applies to all short-wave options.
  • Computation of cosine of solar zenith angle (sza) was wrapped in a single function, so it will make easy to centralize and homogeneize all these computations in future updates. Equation of time correction was included in the sza computations.
  • Three additional variables are now output from all shortwave radiation options (note the output from RRTMG, new Goddard are directly from the routine, and hence more accurate; output from other options are estimates):
    • swddir: All-sky broadband surface direct horizontal irradiance
    • swddni: All-sky broadband surface direct normal irradiance
    • swddif: All-sky braodband surface diffuse irradiance
    (Thanks to Jose Ruiz-Arias, U Jaen, Spain for the above)
  Nudging
  
  • obs_nudging: regime calculation depends on surface layer option rather than PBL option
  Initialization/IO:
  • real: if one uses smooth_cg_topo option, the effect is now extended to all boundary conditions
  • ndown: model run after ndown is now able to use microphysics and scalar variables in boundary condition file which was added in V3.5. One needs to use these options in &bdy_control to turn it on: have_bcs_moist and have_bcs_scalar = .true. It is recommended that the same microphysics options in both model runs are used so that correct boundary conditions for the same variables can be applied.
  • restart: if one wants to change IO frequencies in a restart run, one must use additional namelist override_restart_timers = .true.
  Software:
  New Features
  • Now there is only a single masked interpolation scheme that is used: interp_mask_field. This single scheme makes maintenance easier and insures consistency with land and water fields. The original interpolation subroutines were not removed from share/interp_fcn.F. The iswater or isice flag is supplied in the call from the Registry.EM_COMMON, so there are no problems with trying to internally determine what field is being interpolated, and whether the mask should be based on ice or water.
  • Fixes for compile problem associated with IBM compilers
  • Minor changes for FX10 support (Thanks to Fujitsu)
  • Cray/PGI option added back
  • Fix for errors (seg faults) traversing linked list of statevars in frame/module_domain.F. Errors occur occasionally because of uninitialized data in the head of the linked-list, which should not be part of the traversal. This is a bug in the WRF code in general and would affect any users who use the "Run time control of IO stream variable sets" facility described in README.io_config (posted since 5/29/2013).