V3.9.1.1

WRF Model Update
The WRF model tar file has been updated to Version 3.9.1.1 on August 28, 2017. For known problems in V3.9.1.1, please click here

There are no updates to the WRF Pre-Processing System (WPS).

If you are interested in seeing how V3.9 has been tested, click here.

Improvements and Bug fixes:

Dynamics:

• Diffusion option (diff_opt = 2):

• Fixed file dyn_em/module_diffusion_em.F where some undefined k indices were used outside k loops, instead of kts. This affects the v-wind component computation in the y-direction at the surface over sloped terrain.

V3.9.1

WRF Model Update
The WRF model tar file has been updated to Version 3.9.1 on August 17, 2017. For known problems in V3.9.1, please click here.

The WRF Pre-Processing System (WPS) has been updated to Version 3.9.1.

If you are interested in seeing how V3.9 has been tested, click here.

Improvements and Bug fixes:

Physics:

Atmospheric Radiation:

• swint_opt: This option interpolates solar radiation between radiation steps. At sunrise the method did not use cosine zenith angle information because it only used that when it had two times to interpolate from. This results in a flat shortwave value until the second radiation time after sunrise. The new method can use zenith angle with one time, so it improves the gradient at sunrise.
• Fixed a bug to allow Ferrier microphysics to work with GFDL radiation in WRF ARW..
• Fixed a bug in radiation driver so that KF-CuP (cu_physics=10) clouds impact radiation.

Microphysics:

• Thompson (mp_physics = 8,28) (Thanks to Greg Thompson of NCAR): Fixed uninitialized snow moment arrays, fixed rate_max calculation for frozen categories where density is missing, possible mass conservation voilation.

• P3 (mp_physics = 50,51): Fixed table calculation that results in bad values, and prevented overdepletion of supersaturation during condensation calculation if long time steps are used (~ 1 min). If you're using this scheme in V3.9, get a new table from V3.9.1 (p3_lookup_table_1.dat). Also, P3 is recommended to use ONLY with RRTMG radiation. (Thanks to Hugh Morrison)

Cumulus:

• Grell-Freitas: Fixed a bug that double counts convective ice cloud when cu_rad_feedback is on. (Thanks to Laura Fowler of NCAR)

• G3: Fixed a compile problem due to incorrect calling of 'random_seed when using some versions of gfortran.
  Land Surface and surface layer physics:

• NoahMP (sf_surface_physics=4): Fixed two sign errors in the initialization code for psisat. Also removes two unused arrays from the registry and initialization code and fixed FANGLE parameter calculation. (Thanks to Mike Barlage of NCAR and Gonzalo Miguez-Macho of U. Santiago de Compostela, Spain)

• RUC LSM (sf_surface_physics=3): Improved a problem with initializing this option with GFS/NAM soil data. Before this fix, surface and boundary layer could be significant cooler and wetter when RUC LSM is initialized with GFS/NAM data. This fix improves, but does not remove the biases completely. Use with caution.(Thanks to Tanya Smirnova of NOAA)

• PX surface layer: Changed T* calculation to use virtual potential temp at all time steps instead just the first (Thanks to Jon Pleim and Robert Gilliams of EPA).

• Revised MM5 surface layer: Fixed calculation of PSIT and PSIQ when COARE formula is used in this scheme to be consistent with the general revision made for this scheme. Water surface only.

Dynamics:

• Diffusion option (diff_opt = 2):

• Fixed two mapscale factors in horizontal diffusion for scalars, which affects lat-lon projection (Thanks to Katie Lundquist of LLNL).
• Fixed the slope term that should be outside the vertical derivative (Thanks to Pedro Jimenez of NCAR/RAL).

Initialization/Ndown:

• Program real: Fixed map scale factor assignmeent at the norther and southern edges of a regional rotated lat/lon domain.

• Program real: When using surface_input_source option other than 1, set urban parameters properly if they are generated from geogrid.

• Program ndown: Fixed the bug when physics suite is used in the coarse domain run.

Software:

• Fixed a dependency bug on a removed file (module_diag_afwa_hail.F)

Version 3.9

This is the version 3.9 release of the WRF code. The release includes all components of the system:

• WRF model (including ARW and NMM/HWRF)
• WRF-Chem
• WRFDA

WPS and WRFPLUS have also been updated, but these codes are kept separately from this repository. Click those respective links for further details.

The highlights of the new release are:

WRF ARW model:

• Hybrid sigma-pressure vertical coordinate as an alternative vertical coordinate
• P3 microphysics
• Stochastically perturbed parameter scheme and stochastically perturbed physics tendencies
• Improvement to RAP/HRRR physics and various other physics
• Runtime performance improvement through optimization of advection routines

See http://www2.mmm.ucar.edu/wrf/users/wrfv3.9/updates-3.9.html for full details

WRFDA:

• New assimilation capability: 4DEnVar
• Cloudy radiance assimilation capability for AMSR2
• Radar "null-echo" assimilation

See http://www2.mmm.ucar.edu/wrf/users/wrfda/updates-3.9.html for more information

WRF-Chem:

• TUV photolysis option
• Coupled WSM6 microphysics with MOZART gas wet scavenging
• Modified GOCART dust scheme for the SORGAM and MOSAIC chemistry options
• A new trajectory option that calculates meteorological and chemical properties
  along air trajectories

WRF-NMM-HWRF:

• The 2016 operational update, which includes surface layer and ocean coupling updates; the GFS EDMF PBL scheme, and a scale aware SAS cumulus scheme.

For detailed code changes, updates and to download the latest version of the code, please visit http://www2.mmm.ucar.edu/wrf/users/downloads.html and http://www.dtcenter.org/HurrWRF/users

We would like to thank many people who contributed to the v3.9 release:

Hugh Morrison, Jason Milbrandt, Judith Berner, Joe Olson, Tanya Smirnova,
Georg Grell, Francisco Salamanca, Yizhou Zhang, Xing Liu, Gonzalo Miguez-Macho,
Mike Barlage, Chunxi Zhang, Sebastien Masson, Jihyeon Jang, Kun Liu, Becky Adams-Selin,
Ted Mansell, Greg Thompson, Raquel Lorente, Pedro Jimenez, Jiachun Yang, Yu Gu,
Mei Xu, Tim Glotfelty, Kiran Alapaty, Josh Laughner, Brian Reen, Milan Curcic,
Negin Sobhani, Davide Del Vento, Samuel Elliot, Patricia Balle, Pete Johnsen,
Laura Fowler, Robert Gilliam, Katie Lundquist, William Gustafson, Jim Bresch,
Kevin Manning, Mark Seefeldt, Jose Renteria, Wei Yu, Saulo Freitas, John Cazes,
Balwinder Singh, Megan Bela, Chun Zhao, D. Lowe, K. Wang, P. Tuccella, Branko Kosovic,
S. McKeen, R. McVay, Mary Barth, P. Saide, M. Hirtl, Y. Zhang, G. Pfister, Y-H Ryu,
David Avisar, Hongli Wang, Yu-Shin Kim, Ki-Hong Min, Yuanbing Wang, Xiaowen Tang,
Thomas Schwitalla, Yuanbing Wang, Jeffrey Willison, Chun Yang, Heimo Truhetz,
Nils Gustafsson, Feng Gao, National Water team, NCEP HWRF team, Fujitsu Japan and Taiwan

Version 3.8.1

This is the version 3.8.1 release of the WRF modeling system.

Updates

The WRF model, WRF-DA and WRF Chemistry codes have been updated. Some of the bug fixes and improvements are:

WRF model:

• An important fix for MYNN PBL scheme with icloud_bl (default)
• Significant update for icloud=3 option
• Significant update for the new Tiedtke scheme
• Bug fixes and improvements for a number of physics options and diffusion option in physical space

For full details, see http://www2.mmm.ucar.edu/wrf/users/wrfv3.8/updates-3.8.1.html

WRFDA:

Several bugs have been fixed. For full details, see http://www2.mmm.ucar.edu/wrf/users/wrfda/updates-3.8.1.html

#Acknowledgements
We would like to thank everyone who contributed to this release, including:

A. Callado Pallarès, Laura Fowler, Xiaohui Zhong, Bonnie Brown, Glen Romine, Jared Lee, Tanya Smirnova, Joe Olson, Jin-Fang Yin, Hugh Morrison, Bill Gustafson, Chunxi Zhang, Mike Barlage, Greg Thompson, Brian Reen, Stefen Tulich, Chengguang Li