WRF-NMM Users Page

WRF Modeling System Updates

The WRF model tar file has been updated to Version 3.3.1 on September 22, 2011.

The WRF Pre-Processing System (WPS) has also been upgraded to Version 3.3.1.

WRF Version 3.3.1 improvements and bug fixes

WRF-NMM specific updates

  • Fixed uninitialized variables

HWRF specific updates

  • SAS scheme (namelist option 84): fixed an out-of-bounds bug. Impacts: This bug caused the code to crash on Linux with PGI compiler. It also cause the model outputs to be different on different platforms (such as IBM and Linux/Intel)
  • The CO2 transmission coefficient table now is calculated at runtime, instead of using a hardwired input.

General updates


  • Microphysics:
    • Thompson microphysics: modified fall speed; changed graupel size distribution (small effect); fixed processor-count-dependent results (thanks to A. Lenzen)
    • WDM5, WDM6: fixed missing density term in auto conversion from cloud to rain, resulted in reduction of cloud water mixing ration (thanks to M. Gilmore)
    • SBU scheme: unit correction (small effect)
    • Morrison scheme: fixed a number of issues (see detail in phys/module_mp_morrison.F
      • replaced kinematic with dynamic viscosity
      • replaced scaling by air density for cloud droplet sedimentation with viscosity-dependent Stokes expression
      • use Ikawa and Saito (1991) air-density scaling for cloud ice
      • corrected typo in 2nd digit of ventilation constant F2R
      • unit correction to use Kelvin (not Celsius) for temperature for accelerated melting due to collision of snow and grupel with rain (reported by K. Van Weverburg)
      • fix to not subtract NPRACS from snow number concentration since decrease in snow number is already accounted for by NSMLTS
      • fix in switch for running w/o graupel/hail (cloud ice and snow only)
  • Cumulus:
    • GD/G3 cumulus: fix for cloud water conservation (will result in reduction of surface rainfall)
    • GD cumulus: fix to prevent possible division by zero (no effect on results (thanks to E. Kemp)
    • NSAS cumulus: fix for cloud water and cloud ice tendency output for Ferrier and Kessler schemes
  • Planetary Boundary Layer:
    • YSU: minor change to allow the scheme to work with thin surface layer
    • ACM2: increased dimension for message
  • Surface Physics:
    • PX LSM: change to prevent use of landuse categories other than 24 cat USGS (modis support to come in next release)
    • RUC LSM: fixed uninitialized variable (reported by C. Chen); important correction to 2m T diagnstic when RUC LSM is used with MM5 surface layer option
    • sst_update: fixed a problem with two-way nesting when sst field itself is masked
    • Ocean mixed layer: added condition for tml < tmoml, then tml=tmoml
    • Wind-farm (drag): fixed a bug to find wind turbine location (thanks to Y. Ma)


  • grib1: fix to remove uninitialized variable (reported by C. Chen)
  • Add diagnostics for max/min, time of max/min, mean and standard deviation values of surface variables: T2, Q2, U10, V10, skin temperature, time-step rainc (raincv and rainncv). The option is controled by namelist output_diagnostics = 1, and output goes to auxiliary output stream 3 by default (thanks to L. Fita, J. Fernández, and M. García-Díez of Spain)


  • ESMF updated to 5.2.0r
  • p-netCDF support for io quilting: modified to reduce the size of storage needed. This helps to reduce the wrf executable size on some IBMs by a factor of 10 (thanks to A. Porter of UK).
  • bug fix for configuring on a ubuntu or openSUSE system
  • fix for serial build with nesting (revealed by gfortran)