The WRF model tar file has been updated to Version 3.4.1 on August 16, 2012.

The WRF Pre-Processing System (WPS) has also been upgraded to Version 3.4.1.

WRF Version 3.4.1 new features, improvements and bug fixes

HWRF specific updates

• New Capabilities:
• Capability of running 2012 operational Hurricane WRF (HWRF) configuration, which uses three telescopic domains with 27-9-3 km grid spacing
• Additional nest tracking methods for HWRF
• Miscellaneous bug fixes:
• Fixes for Tiedke cumulus and RRTMG radiation parameterizations to work with HWRF

General updates

Improvements and bug fixes

Phyiscs:

• Resetting cudt = 0 for BMJ, all SAS schemees, and Tiedtke since the time-step rain is not correctly calculated when adaptive time is used. The time-step rain is used in LSM.
• Bug fix for cumulus calls if adaptive time stepping is used with OpenMP, either by setting numtiles to > 1 or OMP_NUM_THREADS > 1. The bug caused cumulus calls to only happen in the first tile (Thanks to Todd Hutchinson of WSI).
• Glacier ice treatment has been moved out of Noah code and replaced by a call from surface driver to seaice_noah
• NoahMP: bug fixes and its namelists have been changed to single value or non-domain-dependent
• MYNN surface layer: added iz0tlnd option, modified isftcflx options (see README.namelist for details)
• MYNN PBL: added option to output diagnostics (bl_mynn_tkebudget = 1), some tuning of the scheme
• YSU: fix for stable surface conditions (Thanks to Basu) and consistency with thermal roughness length. The change may result in an improvement in surface wind forecasts at night.
• YSU: bug fix for nesting starting at a later time due to introduction of 'topo_wind' option, even if the option is not used
• QNSE/EDMF: bug fix for EDMF (day-time) (Thanks to Steven Decker of Rutgers)
• SSiB: activate seaice function
• isftcflx = 2: Cd and Ck changed to 2012 ARW RT runs (not yet in revised surface scheme, sf_sfclay_physics = 11)
• Thompson MP: update to graupel intercept parameter and others
• GD and G3 schemes: correct the bug that several extra fields did not have values when cu_diag is on (Thanks to Bart Brashers of Environ)
• Add feedback to surface diagnostic fields: T2, TH2, Q2, U10, V10 and PSFC (Thanks to Robert Fovell of UCLA)
• SKEB option: fixed a problem allocating arrays before de-allocating them first (Thanks to Glenn Creighton of AFWA)
• Variable description changed for 'climate diagnostic' output variables

Others:

• Input sounding for idealized two-fire example updated. Previous one did not work
• Program ndown: fix to use default hypsometric_opt = 2 option (posted 5/4/2012)
• Program real: since V3.3, the top half-level of Qv coming out of the real program (ARW only) has been zero. This is fixed in this release.
• Bug fix associated with writing history file after restart: History output will not be written out at the time of restart. If one would like to have it, use namelist option 'write_hist_at_0h_rst = .t.' . The bug caused this unpredictable behavior. Using 'override_restart_timers' option will also work if one would like to change the output interval to a larger value. However, using the option 'override_restart_timers' may not work correctly if fdda and sst_update options are used, unless the restart time is also the time when data is available.

Experimental features:

• netCDF4 compression and chunking features: with this option and current parameter setting, the file size can be reduced up to 45%. However, it is a bit clumsy to use this option in this release, unless you are running on bluefire at NCAR. It will require installation of serial version of HDF and then netCDF4. The option is activated at compile time by adding these additional macros in configure.wrf file just above the line "DMPARALLEL = 1"
  
  NETCDFPATH = /your-netcdf4-path/lib/netcdf/4.1.3_seq
  HDFPATH = /your-hdf-path/lib/hdf5/1.8.7_seq
  ZLIBPATH = /your-zlib-path/lib/zlib/1.2.5
  NETCDF4_IO_OPTS = -DUSE_NETCDF4_FEATURES \
  -DWRFIO_NCD_LARGE_FILE_SUPPORT
  
  # Modify existing WRF Makefile macros
  
  LIB_LOCAL = -L$(NETCDFPATH)/lib -lnetcdf -lnetcdff -lgpfs \
  -L$(HDFPATH)/lib -lhdf5 -lhdf5_hl \
  -L$(ZLIBPATH)/lib -lz
• Adding in-code radar reflectivity calculations for the following schemes: WSM5/6, WDM5/6, Thompson, Morrison, Goddard, and Lin
  
  The calculation is done only at output time and can be activated via namelist option do_radar_ref = 1 in &physics. Whether you use this option or not, a new array refl_10cm will appear in wrfout file.
• Pressure level diagnostics, controlled by new namelist record &diags:
  
  &diags
  p_lev_diags = 0
  num_press_levels = 4
  press_levels = 85000, 70000, 50000, 25000
  use_tot_or_hyd_p = 2
  /
  
  Variables available are: U, V, Temp, RH, geop height, wind speed and dew point temp. Output goes to auxhist23 by default. Other relevant namelists can be found in test/em_real/examples.namelist.