WRF Version

The WRF model has been update to Version v.4.8.0 on June 8, 2026

Acknowledgements: We would like to thank

• Alexander Ukhov (KAUST)
• Anders Jensen NOAA/GSL
• Balthazar Sengers, Fraunhofer IWES, Germany
• Barry H Lynn (Weather It Is, LTD and Hebrew University of Jerusalem)
• Tzu-Shun Lin (NCAR)
• Yuqi Huang (University of Oklahoma)
• Chenghao Wang (University of Oklahoma)
• Cenlin He (NCAR)
• Haiqing SONG (宋海清) Ecological and Agricultural Meteorology
• Haiqin Li ([email protected], CIRES/CU Boulder at NOAA/GSL)
• Jack Bartlett (Imperial College London)
• Joseph Olson (NOAA/GSL)
• Xia Sun (NOAA-GSL)
• Lluís Fita Centro de Investigaciones del Mar y la Atmósfera
• Massimo D'Isidoro (ENEA - Italian National Agency for New Technologies, Energy and Sustainable Economic Development)
• Menda Chasteen
• Miroslaw Andrejczuk (HPE)
• Pedro Jimenez (NCAR/RAL)
• Masih Eghdami (NCAR)
• Sylwester Arabas (@slayoo)
• Songyou Hong (NCAR)
• Wen-Pu Ho (National Central University, Taiwan)
• Yuxuan Xie (IGSNRR, CAS)
• Will Hatheway

for their contributions to this release.

Physics

• A new dynamic lightning scheme is added. The scheme of Lynn et al. (2012) is a prognostic lightning parameterization and it predicts the temporal evolution of a bulk potential electric energy associated with deep convection. Activated by dyn_lightning_option = 1. The DLS includes a simple scale-aware formulation that adjusts charging intensity relative to the original 4 km configuration. (#2276) Details

• New version of Shin-Hong PBL that combines YSU scheme replaces bl_pbl_physics =11. Other new options are: shinhong_scu_mixing (top-down mixing, default off), shinhong_nonlocal_flux (gamma (f) or mass flux (t), default on), shinhong_ke_dissipation (tke dissipation heating, default off). The code is moved to shared MMM-physics repository, and available in phys/physics_mmm after compilation. (#2286) Details

• Orographic gravity drag option gwd_opt = 1 is updated. Other added options are gwd_dx_factor = 2 (effective grid size) and gwd_if_nonhyd = .true. (nonhydrostatic effect option). Requires the use of orographic fields from WPS code updates (wrf-model/WPS#281) when using this option. (#2285) Details

• Added a scale-aware turbulent orographic form drag option (kim_tofd) in revised MM5 surface layer scheme. The default value for the option is off and it would increase surface drag. Use this new option with care. Requires the use of var2 field from WPS code updates (wrf-model/WPS#281) when using this option. (#2284) Details

• Coupling with refactored Noah-MP v5.1.2. This new version of NoahMP has a few new options and improvements compared to the previous Noah-MP v4.7 in WRF v4.7.1. (#2268) Details

• New elements for single-layer urban canopy model (UCM): addition of urban ground vegetation and street trees into the single-layer UCM.
  This extension is based on the following two manuscripts in development.
  Huang, Y., Wang, C., & He, C: Integrating nature-based solutions into the WRF-urban modeling system (in preparation).
  Wang, C., Huang, Y., Miller, D. L., Katz, D., & Ghosh, A. K: Analytical view factors for urban canopy models with trees: model development and case study in New York City (in preparation). (#2272) Details

• The MYNN-EDMF submodule has been updated to be consistent with the updated NOAA Tech Note

  • revised subgrid clouds option (bl_mynn_cloudpdf = 2) improves the low-level clouds.
  • improve the scale-awareness as well as the underlying physical representation of downdrafts.
  • a handful of related revisions/tunings was made to improve low level jet structures in stable conditions for several WFIP3 cases.
  • update to mixing of anthropogenic aerosols

  Beware of the new MYNN-EDMF-specific options (bl_mynn_mixaerosols, bl_mynn_mixnumcon, and bl_mynn_mixscalars). Their defaults may not be suitable for your research/applications, but in general, we suggest to use this options and set scalar_pblmix=0 and tracer_pblmix=0, since the MYNN can perform the associated nonlocal mixing.
  (#2267) (#2336) (#2291) (#2319) Details

• The MYNN surface layer scheme has been updated to the new modularized submodule version. It has been decomposed into 3 different modules for land, water, and ice. New MYNN-specific options (sf_mynnsfc_sfcflux_land and sf_mynnsfc_sfcflux_water) have been added to replace the shared options (iz0tlnd and isftcflx) that carried different meaning for different surface layer schemes. (#2277) (#2290) (#2311) Details

• Coupling the Community Fire Behavior model (Jimenez et al., 2024): https://gmd.copernicus.org/preprints/gmd-2024-124/gmd-2024-124.pdf (#2279) (#2315) Details

• The Grell–Freitas (GF) cumulus convection scheme has been further developed as the Grell–Freitas–Li (GFL) submodule, which is implemented consistently across WRF, MPAS, and CCPP. Major updates include improved aerosol–convection interactions, several simplified approaches for cold-pool parameterization, and a new scale-awareness feature with subsidence spreading. References: Li, H., G. Grell, and Freitas, S. (2026): Aerosol-dependence of cumulus convection in the United Forecast System (UFS) Weather Model, to be submitted. Grell, G., S., Freitas, and Li, H. (2026): A New Scale Aware Technique for Convective Parameterizations, to be submitted. (#2269) (#2314) Details

• TEMPO is the Thompson-Eidhammer Microphysics Parameterization for Operations. (#2270) (#2293) (#2302) Details

  TEMPO lives here: https://github.com/NCAR/TEMPO and technical documentation lives here: https://ncar.github.io/TEMPO/.

  TEMPO specific release notes are here:
  https://github.com/NCAR/TEMPO/releases/tag/tempo_v3.0.0
  TEMPO version 3.0.0 is the current release version.

  In WRF, supported namelist options include tempo_aerosolaware==1 to use the aerosol-aware version, and tempo_hailaware==1 to use the hail-aware version. Both options are off by default.

  Info on table building can be found here: https://ncar.github.io/TEMPO/program/build_tables.html

  Prebuilt tables are available from from the TEMPO/tables directory (permalink) (this table is already in the WRF/run directory, it needs to be named in lower case ccn_activate.bin):
  TEMPO/tables/ccn_activate.bin

  The larger tables are available via a NOAA server, and can be obtained with wget:

  wget -q https://gsl.noaa.gov/thredds/fileServer/retro/jensen/qr_acr_qg_data_tempo_v3
  wget -q https://gsl.noaa.gov/thredds/fileServer/retro/jensen/qr_acr_qs_data_tempo_v3
  wget -q https://gsl.noaa.gov/thredds/fileServer/retro/jensen/freeze_water_data_tempo_v3
  

Diagnostics

• CORDEX WRF First version (v1.3) of the module was accompanied by an article in GMD: (#2245) (#2322) Details
  Lluís Fita, Jan Polcher, Theodore M. Giannaros, Torge Lorenz, Josipa Milovac, Giannis Sofiadis, Eleni Katragkou and Sophie Bastin, 2019: CORDEX-WRF v1.3: development of a module for the Weather Research and Forecasting (WRF) model to support the CORDEX community, Geosci. Model Dev., 12, 1029-1066, 2019, doi 10.5194/gmd-12-1029-2019

  Current version of the module is v.3 and it provides about 150 new diagnostics a new section in the namelist.input labelled &cdxwrf with new parameters. Outputs are grouped in 3 files:

  • wrfcdx_d<domain>_<date>: main output file at auxhist19 with most of the variables
  • wrfhfcdx_d<domain>_<date>: high-frequency (e,g, 10 minutes) output file at auxhist18 only for RAIN and COLMAX implemented to assist the tracking convective systems
  • wrfpress_d<domain>_<date>: p-level interpolated variables at auxhist23 with the additional variables

  You can find more details in the CDXWRF WIKI

• Corrected a bug in the WRF time series output, when solar_diagnostics is activated, where the last variable (ts_swddnic2) was written in a separate record. TS files now correctly includes all the 55 variables on the same record. (#2265) Details

Chemistry

• Fix calculation of dry air density in module_chem_utilities.F. The bug had a very minor effect. (#2185) Details

Hydro

• Hydro bug fixes plus modifications to add initial support for gage-assisted diversions in channel routing, which requires a new optional Diversion netCDF parameter file. This adds a C compiler dependency (#2263) Details

Software

• Critical bug fix of core uninitialized values causing undefined behavior. Common manifestation of bug was model hangs during first restart write. (#2300) Details
• Critical bug fix to ensure clearing of data handle upon freeing. Common manifestation of bug was sudden model crash when reading auxinput data. (#2292) Details
• Add MMM-physics as a git subm...

The WRF model has been update to Version on June 2, 2025

Acknowledgements: We would like to thank

• Einara Zahn, Princeton University
• Max Balsmeier

for their contributions to this release.

Physics

• Corrected evaporation rate calculation for water budget over impervious surfaces in SLUCM when IMP_SCHEME == 2. Affects available water in impervious surfaces and latent heat flux output in urban simulations with impervious scheme enabled. (#2227) Details

Software

• Fix compilation with GCC 15 by correcting function declaration syntax to explicitly list function arguments. (#2228) Details
• Add dependent files to custom command call to enable recompilation timestamp check (#2221) Details
• CMake bug fix to ensure ideal cases compile correctly again. (#2229) Details
• Bugfix: CMake confcheck result variables passed correctly to main CMakeLists.txt. (#2219) Details
• Fix in KPP compilation during integration edit to use correct make variable (#2222) Details
• Fix errant line contiuation syntax in chem code (#2223) Details
• In collect_on_comm.c, use a temporary pass through errhandler to allow MPI_Type_match_size to fail correctly with error code rather than fully abort the program. (#2231) Details

Miscellaneous

• Modify MYNN PBL descriptions (#2230) Details
• Fix and clarify the README.namelist regarding MYNN PBL scheme. (#2220) Details

NOTE!!!! : If downloading the files from the section below, please choose either the v4.7.1.tar.gz file, or the v4.7.1.zip file. DO NOT choose those named "Source Code." They do not include the mandatory NoahMP, MYNN-EDMF, and MMM-physics submodules - needed for compiling WRF.

The WRF model has been update to Version v4.7.0 on April 25, 2025

Acknowledgements: We would like to thank

• Adam Dury (WeatherQuest)
• Andrea Zonato, Royal Netherlands Meteorological Institute (KNMI)
• Benjamin Kirk & Negin Sobhani (NSF NCAR / CISL)
• Cenlin He @cenlinhe and Tzu-Shun Lin (NCAR)
• Charlie Li, software developer from lakes environmental, Canada
• Jakub Lewandowski (University of Leeds)
• James Ruppert (University of Oklahoma)
• Joseph Olson (NOAA/GSL)
• Alexander Ukhov (KAUST)
• L. Fita (UBA/CIMA/IFAECI)
• Lukas Pilz (Heidelberg University)
• Martilli, Alberto (CIEMAT)
• Mathieu Landreau (Centrale Nantes)
• Min Chen of IUM/CMA
• Robert Conrick (U. of Washington)
• Robert Gilliam & Jon Pleim, US EPA
• Sergey Osipov (KAUST)
• Song-You Hong
• Tanya Spero (U.S. EPA)
• Ted Mansell (NOAA/NSSL) (@MicroTed )

for their contributions to this release.

Physics

• Fix an error associated with using LCZ categories in NoahMP. Prior to this fix, the LCZs were not correctly referenced, hence ignored in the NoahMP code. (#2202) Details
• NSSL-mp bug fix for (obsolete) droplet nucleation (#2195) Details
• NSSL microphysics scheme updates include 1. An explicit rain breakup for 3-moment rain (addresses issue of cold pools being too warm and drops being too large in rain cores), 2. Improved reflectivity conservation for graupel->hail conversion and drop freezing, 3. More accurate saturation mixing ratio calculation, 4. New default droplet nucleation that controls excess supersaturation much better than previously (and default is to always predict the number of activated CCN). The update has been submitted to CCPP repository as well. (#2170) Details
• An new microphysics, UFS Double Moment (UDM), 7-class microphysics from Songyou Hong is added (mp_physics=27). UDM mp largely adopts microphysical processes in WDM7, but with bug fixes or revisions based on literature and accumulated realism. UDM mp utilizes the in-cloud microphysics concept (Kim and Hong 2018), with the addition of water-friendly aerosols for CCN initialization. Semi-lagrangian sedimentation of Juang and Hong (2010) is also re-configured for computational efficiency and numerical accuracy. All production terms are optimized by introducing a cloud-top definition for hydrometeors. (#2147) Details
• Release of the RCON Microphysics package into WRF, which improves upon the warm rain representation of the Thompson-Eidhammer scheme. RCON is based heavily on the Thompson-Eidhammer scheme with a couple significant changes that improve upon the code in module_mp_rcon.F to generate more realistic rainfall during warm rain events with additional benefits for cold rain, especially warm processes during cold rain events. Among the most significant changes for rain productions are 1) the use of a wider cloud water DSD of lognormal shape instead of the gamma DSD used by the Thompson-Eidhammer parameterization and 2) enhancement of the cloud-to-rain autoconversion parameterization to accommodate the new shape. The changes here also allow for sedimentation of cloud water within the lowest model layer, which effectively creates a drizzle mode in the scheme. Accompanying published reference: Conrick, R., C. F. Mass, and L. McMurdie, 2023: Improving Simulations of Warm Rain in a Bulk Microphysics Scheme. Mon. Wea. Rev., 152, 169-185, https://doi.org/10.1175/MWR-D-23-0035.1. (#2144) Details
• Submodule implementation of the MYNN-EDMF (https://github.com/NCAR/MYNN-EDMF). The module names changed from mynn to mynnedmf to resolve a version conflict in MPAS. This version was originally developed within FV3/CCPP for RRFSv1, but has been refactored (to a k-only scheme) resulting in a speed-up of about 10-15% and it has since been tuned to better perform in MPAS and WRF compared to previous versions which were primarily developed for use in FV3. (#2148) Details
• Fix an erroneous print for using ghg_input when no radiation option is selected, mostly from idealized cases. (#2199) Details
• Fix a loop index error in bep_bem urban code. (#2196) Details
• Noah-MP bug fixes for (1) allowing BATS snow albedo scheme for nighttime snow aging, (2) the potential leakage caused by calculate_soil variable during parallelized run, (3) the missing of HCPCT output for glacier points. (#2160) Details
• The similarity stability functions phim and phieps, necessary for calculating the surface values of tke and dissipation rate in the tke-epsilon-tpe PBL scheme Zonato et al., 2022 have been updated considering the correction term accounting for the roughness length z0. No relevant differences are found in temperature, wind speed, and humidity. Regarding turbulence variables, the stable case has just negligible differences, while the unstable case shows higher values of TKE and dissipation rate and lower values of temperature variance. (#2120) Details
• Pleim-Xiu LSM is now compatible with 61 category MODIS LCZ landuse dataset. A mode of latent heat effects on Tg from vegetated parts and from wet leaves is added to Pleim-Xiu LSM. (#2023) Details

Software

• Determine MPI Data Types in col_on_comm() & dst_on_comm() to prevent displacements overflow. (#2157) Details
• CMake README documentation on _ROOT variables (#2190) Details
• CMake README documentation typo fixes (#2189) Details
• Fix aarch64 GCC build when DM configuration selected (#2192) Details
• Fixed failed compilation with Intel oneAPI by reworking the dependency linking of hydro CMake compilation (#2178) Details
• Fix compilation of grib2 IO in make build (#2191) Details
• Fix uncontrollable building of external/io_netcdfpar folder for all stanzas (#2181) Details
• Suppress MYNN-EDMF verify checkout command (#2188) Details
• Fix typo in confcheck CMakeLists.txt for FSEEKO (#2179) Details
• Add quotes to optimization flags exceptions in CMake (#2180) Details
• CMake Chem and Chem+KPP Build (#2018) Details
• Consistent double precision definitions (#2099) Details
• CMake Fix split command flags to be correctly populated (#2108) Details
• CMake WRFPLUS (#2089) Details
• Override CMake-injected optimization flags in favor of the flags set by the build system and provided stanza information. (#2138) Details
• Fixed CMake dev warning project() should be called prior to this enable_language() call appearing when using configure_new script with some newer versions of Cmake. (#2125) Details
• Add documentation to custom properties in CMake to fix compatibility with older versions. (#2131) Details
• Remove leading -D on defines during stanza reading to allow older versions of CMake to configure properly. (#2130) Details
• Bug fix in CMake FindnetCDF.cmake for empty --has-* nc-config fields (#2135) Details
• CMake confcheck switch to try_* functions (#2090) Details
• Bug fix in landread.c to address undefined behavior by adding an explicit return statement in GET_LANDUSE() function (#2197) Details
• Fix memory leaks related to arrays being allocated without being deallocated in start_em and time series calculation subroutines. (#2139) Details
• Fix an access violation error when a PGI compiler is used with urban variables in module_bl_ysu.F when urban option is turned off and the memories of those arrays are not available. (#2137) Details
• Updated grav_settling code to better recognize the land use type so it doesn't crash. Also update the error message if it does crash to go into the rsl.error files rather than rsl.out files. (#2110) Details
• Bug fix for wrfinput where LCZ urban cells in LU_INDEX were overwritten with default USGS urban category. (#2153) Details
• Add manage_externals tool to access physics modules in MMM-physics git repository. (#2126) Details
• When the namelist option write_hist_at_0h_rst is set to .true. under &time_control, history write-out will now be conducted for the first time step fo...

The WRF model has been update to Version v4.6.1 on October 16, 2024.

Acknowledgements: We would like to thank Jeronimo Bande (IDING SAS), Jesus Fernandez, Andrés Simón-Moral and Josipa Milovac (Instituto de Física de Cantabria, CSIC-Universidad de Cantabria, Spain), Parag Joshi (Brookhaven National Lab), Katia Lamer (Brookhaven National Lab), Tanya Spero and Jeff Willison (U.S. EPA), and Ted Mansell (NOAA/NSSL) for their contributions to this release.

This is a bug fix release. Following are fixes associated with this release.

Physics

• Correct the shortwave radiation balance at the wall, particularly the reflected direct and diffuse radiation reaching the wall which leads to underestimation of SW radiation at the wall. (#2101) Details
• Fix non-initialized 3D moisture field in pressure- and height-level diagnostic interpolation. (#2104) Details
• Fixes for the calculations for PSIM in the mos subroutine and the temperature used in surface energy balance for the green roof. The later follows the OSU1DPBL document located at: [https://ftp.emc.ncep.noaa.gov/mmb/gcp/ldas/nceplsm/OSU1DPBL/OSU1DPBL-userguide.pdf] (#2038) Details
• Lech's stability functions are corrected following the original formulation in the single layer urban canopy model. (#2032) Details
• Fix for rare undefined zol in sfclayrev. (#2105) Details
• Bug fixes for parameters associated with the heat transfer coefficient for the upward heat flow over PV panels. (#2049) Details
• Fixed the bug of missing radar reflectivity in WSM6 scheme when do_radar_ref is set to 1. This bug was introduced when WSM6 scheme was moved to physics_mmm/ directory, and shared with other MMM models in v4.6. (#2098) Details

Data Assimilation

• Bugfix for duplicated allocation and file closing for radar_rhv_opt = 2 (#2078) Details

Chemistry

• Expanded global attributes to the full suite for auxiliary history files. Also added two global attributes when the WRF-CMAQ model is invoked (WRF_CMAQ_OPTION and DIRECT_SW_FEEDBACK). (#2044) Details

Software

• Compilation Tests for ARW (#2115) Details
• CMake compilation flags as categorical properties (#2088) Details
• CMake improve configure_reader.py script (#2087) Details
• Fix fseek test (#2055) Details
• Restructure netCDF find modules to use modern import target (#2054) Details
• CMake Prepare for alternate core selections (#2086) Details
• Change internal flag organization in CMake build to not be global (#2053) Details
• Breakout deallocation calls into simpler smaller files (#2070) Details
• CMake build no longer uses generator expressions in defines (#2056) Details
• Break out module_dm external subroutines into separate files (#2069) Details
• Restructure alloc space calls into simpler smaller files (#2068) Details
• Introduce a modularized testing framework that allows testing locally and natively on HPC systems that lives within the WRF repository (#2095) Details
• Add explicit casts to mismatched pointer types in rsl_lite (#2062) Details
• Replace nonstandard isnan() call with value input checks instead (#2061) Details
• Fix line continuation syntax causing problems with certain compilers (#2060) Details
• Remove unsupported -auto C flag from Intel oneAPI stanza (#2059) Details
• Fixed a compile problem with .F90 source files on case-insensitive file systems. (#2057) Details

Miscellaneous

• The documentation of a few namelists is updated in this PR. (#2074) Details
• Corrected end date for em_b_wave test case (#2107) Details

NOTE!!!! : If downloading the files from the section below, please choose either the v4.6.1.tar.gz file, or the v4.6.1.zip file. DO NOT choose those named "Source Code." They do not include the mandatory NoahMP submodule - needed for compiling WRF.

This is the Version 4.6 release of the WRF Model. This release includes all components of the system: WRF-ARW, WRF-Chem, and WRFDA.

Acknowledgements: We would like to thank Kasra Shamsaei (University of Nevada, Reno), Tim Juliano, Domingo Munoz-Esparza, Branko Kosovic (NCAR/RAL), Jun Tang (Amazon), RenChuanhua and Huangxin (Nanjing University), David Robertson (Rutgers University), Kasra Shamsaei (University of Nevada, Reno), Tim Juliano, Branko Kosovic (NCAR/RAL), Cristina Archer (UDEL), Yulong Ma(UDEL;GWA-MWF), Ahmad Vasel-Be-Hagh(Tennessee Technological University), Zhixiong Chen (Fujian Normal University, China),JJ Guerrette (NCAR/MMM, now at tomorrow.io), Deqin Li (Liaoning Meteorological Bureau of CMA), Cenlin He (NCAR), Joseph Olson (NOAA), Laura Fowler (NCAR), Sergey Osipov (KAUST), Daniel Wesloh (Penn State), Do Ngoc Khanh (Tokyo Institute of Technology), Jordan Schnell (NOAA), Soren Rasmussen and Ryan Cabell (NCAR),Parag Joshi and Katia Lamer (Brookhaven National Lab), and Ted Mansell (NOAA) for their contributions to this release.

New features in WRFV4.6

Physics

• Add revised MM5 surface layer scheme from the future shared MMM-physics repository. Detail
• Add new Tiedtke cumulus scheme from the future shared MMM-physics repository. Detail
• Add WSM6 microphysics scheme from the future shared MMM-physics repository. detail
• Add YSU PBL scheme from the future shared MMM-physics repository. Detail
• Add GWDO (gwd_opt=1) code from the future shared MMM-physics repository. Detail
• Add two options (slucm_distributed_drag and distributed_ahe_opt) to WRF SLUCM (sf_urban_physics = 1) so that spatially varying urban morphological parameters (building height, plan area index, frontal area index, roughness length for momentum, and displacement height) can be considered. Detail
• Add salinity effect in MM5 and revised MM5 surface layer schemes. The effect is lower the saturation vapor pressure over ocean by about 2%. Detail
• Add options for three new wind farm parameterizations and their ensembles to account for the individual and overlapping sub-grid wakes of wind turbines within a wind farm. It is recommended to use the new wind farm parameterizations, particularly for coarse resolution, high turbine density, and wind directions aligned with the turbine columns. Detail
• Add 3-moment option to NSSL microphysics scheme (for rain, graupel, and hail) (mp_physics=18). Changes to snow aggregation parameters reduce stratiform reflectivity bias. Also add namelist options to enable/disable bulk CCN prediction and graupel/hail density prediction, and deprecate old mp_physics options (17, 19, 21, 22). Main default parameter changes are for graupel/hail fall speed options (icdx, icdxhl; changed from 3 to 6), and default maximum gr/hail droplet collection efficiencies (ehw0/ehlw0 changed from 0.5/0.75 to 0.9/0.9) See doc/README.NSSLmp for details. A problem is fixed for high resolution vertical domains with nz > 128, where hydrometeor sedimentation did not work at k > 128 (this bug affected most or all previous releases). Detail

Real-Data initialization

• Add a new namelist option "use_sh_qv = T" to allow for choosing to use SH or Qv data directly. If water mixing ratio or specific humidity is available in the metgrid output, they can be used directly in vertical interpolation. Previously these fields are first converted to RH, interpolated vertically, and the water vapor mixing ratio is computed at model levels.Detail

Data assimilation

• Add the capability for assimilating GOES-ABI radiance data. Detail
• Add a lightning data assimilation scheme to assimilate pseudo vertical velocity, divergence fields, or water vapor retrievals from lightning flash rate data. Detail
• Add a background-dependent hydrometeor retrieval scheme for indirect radar reflectivity assimilation. Detail

WRF-FIRE

• Add Scott and Burgan (2005) 40 fuel models for WRF-Fire. Detail
• Add a new Truncated Gaussian scheme to distribute fire heat and smoke in the atmosphere. Detail.

Chemistry

• Add WRF-SoilN-chem, a dynamic ammonia emission model capable of calculating NH3 emission rate interactively with time- and spatial-varying meteorological and soil conditions. Detail

Compiling

• Introduce a CMake build system for em_real and em_ideal as an optional compilation method. Detail. Users are welcome to try and provide feedback.
• Add CMake build option to WRF-Hydro. General bug fixes and code cleanup are also done. MPI routine is more efficient. All hydro file suffixes are now .F90. Detail

Bug fixes and enhancement in WRFV4.6

Physics

• Correct net long wave fluxes for application in modeling urban climate using Single Layer Urban Canopy Model (SLUCM). It slightly improved 2-m temperature in urban area. Details
• Change the behavior of the mp_zero_out flag so that it affects only the 'moist' array, whereas previously it also caused the scalar/chem/tracer arrays to also be set to zero for values below threshold. Now there is a separate flag (mp_zero_out_all) if one wishes to reproduce the old behavior. Details
• Move the call to shalwater_init from module_sf_sfclayrev.F to module_physics_init.F. This is in preparation to make sfclayrev module ccpp-compliant, and potentially make the initialization and physics available to other surface layer modules. Detail
• Fix a bug in Noah-MP for uninitialized leaf mass when LCZ is used. Detail
• Update urban LCZ parameter table (URBPARM_LCZ.TBL) with more reasonable values. Detail
• Update MYNN-EDMF . Detail
• Fix bugs in Noah-MP for snow combination, vegetation fraction scaling, and urban ground heat flux sign. Detail
• Remove zero negative latent heat flux limit (atmosphere to water) in the revised MM5 and original MM5 surface layer schemes. Detail
• Make the Pleim-Xiu LSM compatible with MODIS LCZ. Also, effects of evaporation from transpiration, soil in both vegetated and non-veg parts and wet leaves on ground temperature all are considered. Previously only the effect from transpiration and evaporation from non-veg soil are considered. Detail
• Modify the RUC LSM to add options to the snow model, use real-time vegetation fraction as an indicator for irrigation scheme, and change soil diffusional and hydraulic conductivities. Detail
• Correct diffusion coefficients for tke in LES. Detail

Chemistry

• A building issues with Intel compilers (ifx/icx) for WRF/WRF-chem is addressed. Detail
• Add KPP configure option for alternative libfl name, libfl.so, in addition to libfl.a. Detail
• Fix n2o5 heterogenous namelist option for MADE schemes. Detail
• A bug was introduced after splitting chem_opt 100 and 106. Currently, the chemistry initialization always calls for module_aerosol_soa_vbs routine, leaving the module_aerosol_soa_vbs_HET and corresponding data constants unitialized. As a result, aerosol concentrations are set to 0 after the first time integration (10**-16). This bug is fixed by Differentiate between module_aerosol_soa_vbs and module_aerosol_soa_vbs_het initialization routines. Detail
• Update the registry description for settling velocity of bin 5...

The WRF model has been updated to Version 4.5.2 on December 22, 2023.

Acknowledgements: We would like to thank Mathieu Landreau (LHEEA, Centrale Nantes, France), Marc Imberger (Technical University of Denmark), Alexander Knyazev (Intel), Wei-keng Liao (Northwestern University), Jun Tang (Amazon), Zhixiao Zhang (University of Oxford), Jacob Shpund (Pacific Northwest National Lab), Timothy Brown (AWS), Songyou Hong (PSL/NOAA), Dan Li (Boston University), David Robertson (Rutgers University), Cenlin He (NCAR RAL) for their contributions to this release.

This is a bug fix release. Following are fixes associated with this release.

Physics

• Fix two errors in the WDM6 and WDM7 that have been in the code since V4.0: (1) uninitialized cloud number concentration when cloud is present at the start, and (2) The cloud autoconversion rate was off by a factor of 600. The effect of the first error isn't large, but the effect of the wrong autoconversion rate has resulted in doubling the surface rainfall in some tests (warm rain processes). Details
• Fix a typo in computing saturated specific humidity in the single-layer urban canopy model. The effect is likely small since the calculation is relevant only in the case of rain and on impervious surfaces when using default evaporation scheme (which is set in URBPARM.TBL). Details
• Fix the calculation order in the immediate melting, which was erroneous and based on the hydrometeor state after melting in previous version. In addtion, the calculation method in the supersaturation dynamical tendency is changed to avoid high values of total mass imbalance.Details
• Fix a bug in the code related to trigger condition for CAPE calculation. Details
• Add missing wrf_dm_bcast_real for stc2 in fitch parameterization scheme, which affects standing thrust coefficients for wind speeds at turbine hub-heights above cut-out. Details
• Fix an issue in which time series for a parent domain were re-initialized when a child domain started later than the initial time for a simulation. Details

Compiling

• Add build configuration for new Intel oneAPI LLVM ifx/icx compilers, which is available on NCAR's new computer (Derecho). Details. Note that the option does not yet work for WRFDA and WRF-Chem compilation.
• The fortran library can be either hdf5_hl_fortran or hdf5hl_fortran for HDF5, which is now checked in Config.pl. Details
• Improve the detection and linking with shared and static configurations of the NetCDF-4 libraries (split or unified) inside and outside Spack-Stack to avoid issues when NetCDF-C and NetCDF-Fortran reside in different directories Details
• Add compile defaults for Arm Compiler (armclang/armflang) for Linux. Details
• Resolves building issues with Intel compilers (ifx/icx). Details
• Fixed an error in Makefile to check if USENETCDFPAR is set first. Details

Dynamics

• Fix loop ranges in advect_w for lat-long map projection. This fix only affects polar boundary condition. Details

NOTE!!!! : If downloading the files from the section below, please choose either the v4.5.2.tar.gz file, or the v4.5.2.zip file. DO NOT choose those named "Source Code." They do not include the mandatory NoahMP submodule - needed for compiling WRF.

The WRF model has been updated to Version 4.5.1 on July 25, 2023.

Acknowledgements: We would like to thank Stephen Sachs (AWS), Greg Thompson (NCAR RAL), Michael Laufer (Israel), Andrea Zonato (Koninklijk Nederlands Meteorologisch Instituut), Cenlin He (NCAR RAL), Becky Adams-Selin (Atmospheric and Environmental Research),Samm Elliott (TempoQuest Inc.) for their contribution to this release.

This is a bug fix release. Following are fixes associated with this release.

Physics

• Correct the counter-gradient term for temperature equation at the first level in the KEPS scheme (bl_pbl_physics=17), which causes instabilities and large biases at the first model level over water surfaces. Details
• Make Minor changes to Thompson-MP to align with changes made in CCPP for use in UFS. Details
• Fix a bug related to FVEG scaling of canopy heat storage in Noah-MP canopy energy balance calculations. Details
• Fix problems in HAILCAST quilted processes/tiling and some incorrect SI/non-SI unit conversions. Details
• Fix a bug in building height specification in the LCZ urban parameter table. Details
• Fix an issue in the revised MM5 (sf_sfclay_physics=1) scheme, where the model could potentially encounter an infinite loop. In specific conditions floating point roundoff errors were preventing a convergence condition from ever being met. Details

Compiling

• Make configure script more portable. Details
• Fix the ADIOS2 init API to support ADIOS2 v2.9.0. Details
• Apply type-mismatch for gcc-10 to all gcc targets. Details

Miscellaneous

• Replace a few wrf_messages and wrf_error_fatal calls by macros defined at the top of modules for urban schemes so that the code maintains consistency with those in MPAS. Details
• Update references and remove obsolete contact information related to lightning options (lightning_option = 1 and 2). Details
• Add User-friendly fatal error messages if the optional CESM aerosol data files required for the MSKF cumulus/Morrison microphysics aerosol interaction option (aercu_opt = 1 or 2) are missing. Details
• Remove the file "test/em_real/namelist.input_default", which is more confusing than helpful for users. [Details] (b552930)

NOTE!!!! : If downloading the files from the section below, please choose either the v4.5.1.tar.gz file, or the v4.5.1.zip file. DO NOT choose those named "Source Code." They do not include the mandatory NoahMP submodule - needed for compiling WRF.

This is the Version 4.5 release of the WRF Model. This release includes all components of the system: WRF-ARW, WRF-Chem, and WRFDA.

Acknowledgements: We would like to thank Cenlin He (NCAR RAL), Greg Thompson (JCSDA, UCAR), Anders Jensen (RAL, NCAR), Dylan Reynolds (SLF), Joseph Olson (NOAA-GSL), Wayne Angevine (NOAA-CSL), Andrea Zonato (Department of Environmental, Civil and Mechanical Engineering, University of Trento, Trento, Italy), Jun Tang (Amazon), Jeff Adie (NVIDIA Corporation), Hugh Morrison (NCAR-MMM), Brian Vanderwende (NCAR), Jordan Schnell (NOAA), Kengo Miyamoto (RIST), Zhang Chunxi, Maria Frediani (NCAR RAL), Michael Laufer (Toga Networks, a Huawei Company), Erick Fredj(The Jerusalem College of Technology, Rutgers University, Toga Networks, a Huawei Company), Joseph Brodie (Rutgers University), Lori Garzio (Rutgers University), Sen YANG, Deqin LI, Liqiang CHEN (Institute of Atmospheric Environment, China Meteorological Administration, Shenyang) for their contributions to this release.

New features in WRFV4.5

Physics

• A new package to compute two-moment prognostics for graupel/hail and a predicted density graupel category is added in the Thompson scheme (mp_physics=38). Other updates to the scheme include a change to the Y-intercept relationship for one-moment graupel and replacement of air temperature for wet-bulb temperature in riming and mixed phase processes (Jensen et al., in review). This code requires the datafile "qr_acr_qg_mp38V1.dat" to run, which can be found on the file system for the NCAR community HPC "Cheyenne" under /glade/work/wrfhelp/WRF_files/ and online at http://www2.mmm.ucar.edu/wrf/src/wrf_files/. Details
• A scale-aware or grid-distance-dependent option is added to the new Tiedtke scheme. The code is based on the paper by Wang (2022) with two minor changes removed. The option becomes active automatically when grid sizes is less than 15 km. PR1806 and PR1840
• A new k-epsilon-theta^2 PBL scheme, including two additional prognostic equations for dissipation rate and temperature variance, has been included in the WRF model (see Zonato et al.,2022:A New K–ε Turbulence Parameterization for Mesoscale Meteorological Models. Monthly Weather Review, DOI: https://doi.org/10.1175/MWR-D-21-0299.1). This scheme is designed for finer grids. It works with sfclay=2(time step = 90), sfclay=1(time step = 60), diff_opt=1 km_opt=4). Details

Compiling

• Add support to build WRF on ARM64 (aarch64) architecture systems with the NVIDIA HPC SDK Compilers (nvfortran,nvc). Details
• Provided AMD AOCC Compiler support at the time of configuring WRF for AMD Architectures including Zen1, Zen2 and Zen3. Details

Bug fixes and enhancement in WRFV4.5

Physics

• Substantial updates are added to the MYNN-EDMF, including a reorganization of the subroutines as part of the “universalization efforts”, which are meant to keep the scheme similar in all dycores. The major physics changes include (1) improved conservation of scalars which improves performance in medium-range global forecasting, (2) revised subgrid clouds which leverages the prognostic q’2, (3) vacate bl_pbl_physics = 6 (now only run with bl_pbl_physics = 5); will instead regulate the closure level with new namelist variable “bl_mynn_closure” set to 2.5, 2.6, or 3.0, (4) important bug fixes for the TKE budget and the bl_mynn_tkebudget flag is not renamed to tke_budget for use in other schemes (although may not be hooked up for other schemes yet), (5) new downdraft option (hidden hard-coded flag in module_bl_mynn.F) but still under development to best fit within the MYNN-EDMF, (6) and many miscellaneous tuning/minor bug fixes.Details
• Fix an error with O31D exceeding vertical dimension kte. In WRFV4.4, we introduced ozone output o3rad when o3input = 0, that is to use ozone profile provided by the RRTMG code. But the use of output array accessed memory with the vertical dimension > kte. This can cause segmentation fault on some systems. Details
• Update P3 microphysics. Details
• Bug fix for the vertical levels of TKE in the EEPS scheme and more features are added in this scheme. Details
• Fixed a bug for lightning diagnostic option 3, an option for lightning potential index calculation. The bug prevented nested case to run, and may produce NaNs in the diagnostics. Details
• Fix an issue in roof longwave calculation in the bep_bem urban scheme (module_sf_bep_bem.F), in which a misplaced parenthesis is corrected. Details
• The hard-coded tunable canopy heat capacity parameter in Noah-MP is added to MPTABLE for the convenience of tuning. Details
• Fixed a dimension error for arrays refl, t and z in module_ltng_crmpr92.F.Details
• Update hydro directory to match WRF-Hydro v5.3.0. Details
• NoahMP submodule is updated to its v4.5 branch.Details

Compiling

• Stop intentionally removing OpenMP flags when compiling certain listed source program files, which causes problems with a Fujitsu Fortran compiler. Details
• Change configure to test for RPC package instead of checking hardcoded paths, so that non-standard RPC installs can still be found. Details
• Fix numerical divergence on x86 and arm64. It is recommended to use armclang for best performance of WRF on arm64. Details
• Correct string test in configure to avoid 'Unexpected Operator' error. Details

Data assimilation

• Add a regularized version of WSM6 and its TL/AD for 4DVar with ice-phase hydrometeor analysis variables.Details
• Enhance AHI radiance DA, including all-sky observation error model, Level-2 AHI product read, and more diagnostic output. Details

Chemistry

• Address a bug introduced in WRF v4.3 that affects users using chem_opts = 201 (MOZART_MOSAIC_4BIN_KPP) and 202 (MOZART_MOSAIC_4BIN_AQ_KPP). Users experienced a stalled simulation upon writing history files. This was caused by the pH diagnostics added in v4.3 (#1342) not being activated with the namelist option mozart_ph_diag = 1. Details
• Add an option to use GFS total ozone (2D) in the TUV photolysis (phot_opt=4) to scale the simulated column to the GFS total column in the calculation of photolysis rates. Details
• chem_opt=100 is separated from chem_opt=108 and 109. This is because species in chem_opt=100 (HCL, CLNO2, MG, K, CA) are referenced by the aerosol module for chem_opt=108, 109 leading to memory mapping errors. Details

WRF-Fire

• Update the firebrand spotting parameterization to (1) allow likelihood of spotting on short grass and (2) fix the location and height of ember release. Details

###Miscellaneous

• Fix two numeric operators that are consecutive. Details
• Change the exponent letters of the constants those are compared to double precision variables in SUBROUTINE FIND_RC0 from ‘E’ to ‘D’. Details
• Remove excessive print statements in CLM. Details
• Fix small indexing error in ISHMAEL MP scheme. Details
• Check the existence of WRF_CMAQ. Details
• Update REAME.namelist to include new options and missed pre-existing options.

NOTE!!!! : If downloading the files from the section below, please choose either the v4.5.tar.gz file, or the v4.5.zip file. DO NOT choose those named "Source Code." They do not include the mandatory NoahMP submodule - needed for compiling WRF.

The WRF model has been updated to Version 4.4.2 on December 19, 2022.

Acknowledgements: We would like to thank Cenlin He (NCAR/RAL), Florian Sammüller (Universität Bayreuth), Adam Dury(WeatherQuest)) and Zhang Zhixiao (University of Oxford and University of Utah) for their contributions to this release.

This is a bug fix release. Following are fixes associated with this release.

Physics

• Fix a bug for mixing ratio calculation in Jarvis stomatal conductance scheme in Noah-MP. This fix affects NoahMP option OPT_CRS=2. Details
• Update urban local climate zone (LCZ) numbers in parameter tables to avoid overlap with existing NLCD land types. This update affects VEGPARM.TBL, LANDUSE.TBL, and MPTABLE.TBL. The LCZ numbers in WRF-urban are changed from 31-41 to 51-61. Details
• Fix the units and unit conversions of several variables in subroutines CARBON and CARBON_CROP (NoahMP scheme); update urban pixel identification by including LCZ urban types in module_sf_noahmpdrv.F for surface variable initialization. Details
• Refine CAPE and CIN calculations to be consistent with AMS definitions; improve LFC identification for adapting to multi-inversion layers profiles. Details
• Change the declaration of several variables in subroutine TWOSTREAM from OUT to INOUT, change the soil ice treatment in subroutine COMBINE, correct the units of three accumulated flux variables in Registry, removed the hard-coded 4 soil layers and replace it by the parameter "NSOIL". These changes only affect NoahMP land surface scheme. Details
• Change the declaration of QSFC from OUT to INOUT in sfclay and sfclayrev modules. This is because QSFC is calculated conditionally and at some grid points, it takes the input value. Details

WRFDA

• Update the VAR namelist readme to include change of use_clddet option since V4.2. Details
• Update bufrseviri.inc so that if seviri is turned on in WRFDA after Feb 2018, many error messages in the log file will be suppressed and meteosat 11 data is ingested into WRFDA to be used by the CRTM; correct the CRTM sensor information, add the HIRS4 information file to recognize NOAA 19 and not just NOAA 18 in HIRS4 and AMSUS files; update VARBC.in to include templates of NOAA 15-17 HIRS3 and NOAA 18-19 HIRS4. Details

Compiling

• Fix undefined behavior in RSL_LITE.Detail

Miscellaneous

• Add check to prevent CLM land surface scheme from being used with any urban scheme. Details

If downloading the files from the section below, please choose either the v4.4.2.tar.gz file, or the v4.4.2.zip file. DO NOT choose those named "Source Code." They do not include the mandatory NoahMP submodule - needed for compiling WRF.

The WRF model was updated to Version 4.4.1 on August 25, 2021.

Acknowledgements: We would like to thank Jatin Kala (Murdoch Univeristy, Australia), Louis Marelle (LATMOS, CNRS; Paris, France), J. Shpund (PNNL), Jordan Schnell (NOAA), Robert Gilliam (US EPA), Tim Juliano and Maria Frediani (NCAR/RAL) for their contributions to this release.

This is a bug fix release. Following are fixes associated with this release.

Compiling

• A modification addresses an issue that prevented WRF from compiling when choosing either the specified move (option 2) or vortex-following (option 3) nesting options, while using an Intel compiler. This issue began with WRFV4.4. Details
• Remove duplicate reference to use module_dm in module_stoch.F (added in v4.4), which causes a compilation error when using an older version of the Intel compiler (12.1.3). Details
• Add a check for status code -4001 from Cray CCE Fortran compiler related to reading CAMtr file. Details

Physics

• Fix a minor bug for logical checking of time-varying aerosol option when climatological aerosol option selected. Details.
• Recommend not to use the full spectral bin microphysics until it is updated. Use the fast version instead. Details
• Update VEGPARM.TBL for NLCD40 landuse case to work with recent updates of the LSM initialization that reads the file. Details
• Fix a bug associated with ozone input option o3input = 0. When o3input is set to 0, ozone is effectively not used in the RRTMG radiation option before this fix. Details.

Chemistry

• Add gocart_dust dependency to mosaic_addemiss, which is necessary for WRF-CHEM to compile succeessfully. Details

If downloading the files from the section below, please choose either the v4.4.1.tar.gz file, or the v4.4.1.zip file. DO NOT choose those named "Source Code." They do not include the mandatory NoahMP submodule - needed for compiling WRF.