Namelist Variables

The following are descriptions of namelist.input settings.

Important

Not all namelist parameters are domain-depending (requiring an entry for each domain). Some parameters require only a single entry, and multiple entries will cause a runtime error. In the below tables, note whether variables are “single entry” or “max_dom” entries, where “max_dom” indicates a value is expected for each domain.

See the following resources for additional details and recommendations:

• WRF/Registry/ files

• WRF/run/README.namelist (or WRF/test/em_real/README.namelist)

• WRF/test/em_real/examples.namelist

&time_control

To use the options in this section, they must be set in the &time_control namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
run_days run_hours run_minutes run_seconds	0	Simulation length in days, hours, minutes, and seconds; Use any combination of run_* settings to obtain the desired simulation length. run_* parameters take precedence over start_* and end_* times during wrf.exe; real.exe does not use run_* settings	Single entry

In the following section:

• start_* times name the first wrfout file and control the start time for restarts.

• start_* and end_* times control the start and end time for all domains.

• start_* and end_* times are used by real.exe.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
start_year	2019	4 digit year of simulation start time	max_dom
start_month	9	2 digit month of simulation start time	max_dom
start_day	4	2 digit day of simulation start time	max_dom
start_hour	12	2 digit hour of simulation start time	max_dom
start_minute	0	2 digit minute of simulation start time	max_dom
start_second	0	2 digit second of simulation start time	max_dom
end_year	2019	4 digit year of simulation start time	max_dom
end_month	9	2 digit month of simulation start time	max_dom
end_day	6	2 digit day of simulation start time	max_dom
end_hour	0	2 digit hour of simulation start time	max_dom
end_minute	0	2 digit minute of simulation start time	max_dom
end_second	0	2 digit second of simulation start time	max_dom

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
interval_seconds	10800	time interval between input data from WPS, which will be the interval (in seconds) between times written to the lateral boundary condition file (wrfbdy_d01); em_real only	single entry
input_from_file	.true.	whether WPS input files (met_em.d0*) are used for nest domains; works when max_dom \(\geq\) 2, max_dom
fine_input_stream	0	option to select fields to use from nest input for initialization; = 0 : all fields are used = 2 : only input specified for input stream 2 (defined in Registry) are used for nests works when max_dom=2 or more and when io_form_auxinput2 is set	max_dom
history_interval	60	Frequency (in simulation minutes) that data are written/recorded to WRF historyoutput file(s) (wrfout_d0*); alternatively, use history_interval_d, history_interval_h, history_interval_m, history_interval_s to set the frequency in days, hours, mins, secs, respectfully	max_dom
history_begin	0	indicates the number of minutes, from the beginning of the simulation run, after which the WRF history/output file (wrfout.d0*) is generated; alternatively, use history_begin_d, history_begin_h, history_begin_m, history_begin_s to set the frequency in days, hours, mins, secs, respectfully	max_dom
frames_per_outfile	1	the number of history times bulked into each WRF history/output file (wrfout.d0*); used to split output files into smaller pieces	max_dom
restart	.false.	whether this run is a restart simulation if =.true., must have a wrfrst file for the simulation time start	single entry
restart_interval	1440	the interval (in mins) at which restart output files are written; works when restart_interval is within the simulation timeframe	single entry
override_restart_timers	.false.	the method used for restart output intervals; =.true. : uses restart_interval namelist setting for the restart output interval =.false. : uses all output intervals (including history) given by the wrfrst file works when restart=.true.	single entry
write_hist_at_0h_rst	.false.	=.false. = no WRF history/output file will be written at the restart initial time (prevents overwriting the initial WRF run’s history/output file for this time); =.true. = a WRF history/output file is written at the intial time of the restart; works when restart=.true.	single entry
output_ready_flag	.true.	tells the model to write out an empty file with the name wrfoutReady_d<domain>; useful for production runs in which post-processing code can use this file to check whether the run completed	single entry
force_use_old_data	.false.	=.false. = model stops when it detects input data prior to version 4; =.true. = allow input data prior to WRFv4.0	single entry
reset_simulation_start	.false.	whether to overwrite the simulation start date with the forecast start time	single entry
auxinput1_inname	met_em.d<domain>.<date>	name of the WPS input file used during real.exe; only necessary if not using default file names	single entry
auxinput4_inname	wrflowinp_d<domain>	name of the the lower boundary file created by real.exe; works when sst_update=1	single entry
auxinput4_interval	360	interval in mins for the lower boundary file (wrflowinp_d0*); works when sst_update=1	max_dom
io_form_auxinput4	2	I/O format for wrflowinp files (2 = netCDF format); works when sst_update=1	single entry
io_form_history	2	I/O format of WRF history/output file(s) (wrfout); =2 : netCDF =102 : split netCDF files, one per processor; must restart with same number of processors = 1 : binary format; no supported post-processing software available = 4 : PHDF5; no supported post-processing software available = 5 : GRIB1 = 10 : GRIB2 = 11 : parallel netCDF	single entry
io_form_restart	2	I/O format of restart output files (wrfrst); =2 : netCDF =11 : parallel netCDF =102 : split netCDF files, one per processor; must restart with the same number of processors	single entry
io_form_input	2	I/O format of WPS input files (met_em); =2 : netCDF =11 : parallel netCDF =102 : split netCDF files, allows real.exe to read-in split met_em files, and write split wrfinput files	single entry
io_form_boundary	2	I/O format of the wrfbdy file; =2 : netCDF =4 : PHDF5; no supported post-processing software available =5 : GRIB1 =10 : GRIB2 = 11 : parallel netCDF	single entry
ncd_nofill	.true.	when .true. only processes a single “write” as opposed to “write/read/write” sequence; could potentially improve I/O speed	single entry
io_form_auxinput2	2	IO format for input stream 2 data; =2 : netCDF =4 : PHD5 =5 : GRIB1 =10 : GRIB2 =11 : pnetCDF; works when using ndown and/or when sst_update=1	single entry
diag_print	0	option to print out time series of model diagnostics; =0 : no print =1 : domain-averaged 3-hourly hydrostatic surface pressure tendency (\(Dpsfc/Dt\)), and dry-hydrostatic column pressure tendency (\(Dmu/Dt\)) added to the standard wrfout file =2 : option 1, plus domain-averaged rainfall, sfc evaporation, and sensible and latent heat fluxes	single entry
debug_level	0	a larger value (50, 200, etc.) increases debugging print-outs when running; NOTE: this option is removed from default namelists - rarely provides useful info and adds extra junk to standard error/output files, making them difficult to read and sometimes too large to write - causing runtime crashes	single entry
auxhistX_outname	auxhistX_d<domain>_<date>	when using an option to output additional fields to a file other than wrfout, this is the name of the file that will contain the extra fields; X denotes the stream used (e.g., auxhist9_outname=”auxhist9_d<domain>_<date> for stream 9). Don’t modify the d<domain>_<date> syntax. If necessary, only modify the prefix (e.g., “rainfall_d<domain>_<date>”)	single entry
auxhistX_interval	10	when using an option to output additional fields to a file other than wrfout, this is the output interval (in mins); X denotes the stream used (e.g., auxhist9_interval for stream 9)	max_dom
io_form_auxhistX	2	when using an option to output additional fields to a file other than wrfout, this is the output file format; X denotes the stream used (e.g., io_form_auxhist9 for stream 9).; =2 : netCDF =4 : PHD5 =5 : GRIB1 =10 : GRIB2 =11 : pnetCDF	single entry
frames_per_auxhistX	1000	when using an option to output additional fields to a file other than wrfout, this is the number of WRF history/output times included in each auxhistX output file; X denotes the stream used (e.g., frames_per_auxhist9 for stream 9)	max_dom
auxinput11_interval	10	interval (mins) for observational nudging input; set to the same (or greater) frequency as obs_ionf (with the coarse domain time step); works when obs_nudge_opt=1	max_dom
auxinput11_end_h	6	end of the observation time (in hrs) when using observational nudging; works when obs_nudge_opt=1	max_dom
nocolons	.false.	set to .true. to replace colons with underscores in output file names	single entry
all_ic_times	.false.	set to .true. to instruct real.exe to output a wrfinput file for each time period	single entry
adjust_output_times	.false.	set to .true. to adjust output times to the nearest hour	single entry
output_diagnostics	0	set to 1 to add 48 sfc diagnostic arrays (max/min/mean/std) in the specified time interval; details	single entry
nwp_diagnostics	0	set to 1 to add diagnostic fields (10m wind sp, 2-5 km max helicity, max vert. velocity in updraft and downdraft below 400mb, 2-5 km mean vert. velocity, max column graupel to WRF history/output (wrfout); details; works when do_radar_ref-1	single entry

3DVAR Applications

The following &time_control record options are specific to the 3DVAR application.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
write_input	.false.	set to .true. to write input-formatted data as output for the 3DVAR application	single entry
inputout_interval	0	interval (in mins) when using the write_input option works when write_input=.true.	max_dom
input_outname	wrf_3dvar_input_d<domain>_<date>	output file name from 3DVAR	single entry
inputout_begin_y inputout_begin_d inputout_begin_h inputout_begin_m inputout_begin_s	0	beginning year, day, hour, minute, and second (respectively) to write 3DVAR data	max_dom
inputout_end_y inputout_end_d inputout_end_h inputout_end_m inputout_end_s	0	ending year, day, hour, minute, and second (respectively) to write 3DVAR data	max_dom

Vortex-following with High-resolution Terrain/Landuse Applications

The following &time_control record options are specific to the automatic moving nest application, and with WRF compiled for use with high-resolution terrain and landuse.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
input_from_hires	.false.	set to .true. to use high-resolution terrain and landuse in the nests; works when using special high-res input data and when WRF is compiled with environment variable setting *TERRAIN_AND_LANDUSE - see above link for details	max_dom
rsmas_data_path	path-to-high-res-data-directory	path of the directory where the high-res data is stored	single entry

Run-time I/O Application

The following &time_control record options are specific to the runtime I/O option.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
iofields_filename	my_iofields_list.txt	when this is set, WRF reads this file, which lists variables to add or remove to/from output; user must create this text file (e.g., my_iofields_list.txt) in which variables to add/remove are declared - see above link for details	max_dom
ignore_iofields_warning	.true.	if the file listed for iofields_filename contains an error, WRF continues without stopping; set to .false. to abort the model if an error is encountered	single entry

&domains

To use the options in this section, they must be set in the &domains namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
time_step		time step (in seconds) for model integration set to a value \(\leq\) 6*DX (in km); e.g., for DX=10, set time_step \(\leq\) 60	single entry
time_step_fract_num	0	fractional time step numerator	single entry
time_step_fract_den	1	fractional time step denominator; (e.g., for a 60.3 sec time step, set time_step=60; time_step_fract_num=3; and time_step_fract_den=10)	single entry
time_step_dfi		DFI time step (it’s ok to se to a value different than time_step) works when dfi_opt=1	single entry
max_dom	1	the number of domains to simulate	single entry
s_we s_sn s_vert	1	start index in x (east-west), y (south- north), and z (vertical) directions, respectively. DO NOT change these values	max_dom
e_we e_sn	32	end index in x (east-west), and y (south- north) direction, respectively; staggered dimension	max_dom
e_vert**	31	end index in z (vertical) direction; staggered dimension for full levels (most variables are on unstaggered levels); use the same value for all domains	max_dom
dx dy	200	grid length/resolution (in meters) in the x and y directions	single entry
ztop	15000	height (in meters) used to define the model top for idealized cases	max_dom
grid_id	1	domain identifier	max_dom
parent_id	1	domain ID of the domain’s parent; e.g., for 3 concentric domainsi, set to =1,1,2	max_dom
i_parent_start j_parent_start	1	the i-indice and j-indice where the lower left corner of the nest sits inside its parent domain	max_dom
parent_grid_ratio	1	parent-to-nest grid size (resoluton) ratio; recommend odd ratios (3:1 or 5:1); can be even if feedback=0	max_dom
parent_time_step_ratio	1	parent-to-nest time step ratio; typically set to the same value as parent_grid_ratio, but it doesn’t have to be	max_dom
feedback	1	feeds back data at corresponding points from the nest to its parent; set to 0 to turn off	single entry
smooth_option	2	parent domain smoothing option using feedback; =0 : turned off =1 : 1-2-1 smoothing =2 : smoothing-desmoothing works when feedback=1	single entry
hypsometric_opt	2	when set to 2, real.exe computes height and wrf.exe computes pressure using the hypsometric equation (less biased when compared against input data); set to 1 to use a hydrostatic equation that depends on air density	single entry
max_ts_locs	5	maximum number of time series locations when using the time series option (tslist) works when a ‘tslist’ text file is available in the running directory	single entry
max_ts_level	15	the profile output’s highest model level when using the time series option (tslist) works when a ‘tslist’ text file is available in the running directory	single entry
wif_input_opt	0	option to process additional data specific to aerosol-aware Thompson microphysics =1 : processes Water Ice Friendly Aerosol input from metgrid; see run/README.namelist for details =2 : (new since V4.4) use a black carbon aerosol category and its radiative effect works when file `QNWFA_QNIFA_QNBCA_SIGMA_MONTHLY.dat` is included during WPS, and when mp_physics=28	single entry
num_wif_levels	30	number of levels in the Thompson Water Ice Friendly Aerosols works with mp_physics=28 and wif_input_opt=1; see run/README.namelist for details	single entry

The following &domains record options are specific to running real.exe:

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
num_metgrid_levels	27	number of vertical levels in met_em files; to check, use command ncdump -h met_em.d0* (use the full name of one of the met_em files)	single entry
num_metgrid_soil_levels	4	number of soil levels/layers in met_em files; use command ncdump -h met_em.d0* (use the full name of one of the met_em files)	single entry
eta_levels	(for e.g.) 1.0, 0.99, …, 0.0	model eta levels from 1 to 0. If not specified real.exe provides a reasonable set of numbers	single entry
auto_levels_opt	2	determines how vertical levels are calculated; =1 : (older option) assumes a known first several layers, then generates equi-height spaced levels up to the model top =2 : set dzstretch_s, dzstretch_u, dzbot, and max_dz to stretch levels according to \(logP\), up to to level where max thickness is used (see max_dz), starting from thickness (dzbot)	single entry
max_dz	1000	the maximum thickness (in meters) a layer can be stretched works when auto_levels_opt=2	single entry
dzbot	50	the thickness (in meters) of the lowest layer works when auto_levels_opt=2	single entry
dzstretch_s	1.3	the surface stretch factor (see details)	single entry
dzstretch_u	1.1	the upper stretch factor (see details) works when auto_levels_opt=2	single entry
ideal_init_method	1	option to compute albedo for idealized cases (coded in WRF/dyn_em/start_em.F); =1 : albedo comes from the base state geopotential (phb) =2 : albedo comes from initial potential temp (t_init)	single entry
interp_method_type	2	coarse-to-fine grid horizontal interpolation method; all options (except 2) use the same horizontal scheme for fine-grid lateral boundary computations; =1 : bi-linear =2: Smolarkiewicz (SINT) method; note, can be problematic for large refinement ratios (e.g., 15:1) =3 : nearest-neighbor; only use for testing =4 : overlapping quadratic =12 : uses SINT; only use for testing	single entry

Vertical Interpolation

The following &domains record options are specific to vertical interpolation.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
p_top_requested	5000	pressure top (in Pa) used during simulation; data for this level must be included in met_em* files	single entry
smooth_cg_topo	.false.	set to .true. to smooth the outer rows and columns of the domain 1 topography, with respect to the input data	single entry
lagrange_order	2	the type of vertical interpolation order used during real.exe; =1 : linear =2 : quadratic =9 : cubic spline	single entry
force_sfc_in_vinterp	1	when set to \(\geq\) 1, this is the number of eta levels that are forced to use the surface during vertical interpolation; set to 0 to turn off and use traditional trapping interpolation	single entry
use_levels_below_ground	.true.	whether to use levels below input data’s sfc level during real.exe vertical interpolation; =.true. : use input isobaric levels below input surface =.false. : extrapolate when WRF location is below input surface level	single entry
use_surface	.true.	use input surface-level data during real.exe vertical interpolation	single entry
lowest_lev_from_sfc	.false.	the method used for eta level interpolation; =.true. : for u,v,t, and q, use the surface value for the lowest eta level =.false.: use traditional interpolation	single entry
sfcp_to_sfcp	.false.	when input data does not include sea-level pressure, set to .true. to compute model surface pressure when incoming data only has surface pressure and terrain	single entry
interp_theta	.false.	determines whether to vertically interpolate temperature and or potential temperature; =.false. : vertically interpolates temperature (may reduce bias when compared with input data) =.true. : vertically interpolates potential temperature	single entry
interp_type	2	type of vertical interpolation; =1 : vertical interpolation is linear in pressure =2 : vertical interpolation is linear in log(pressure)	single entry
extrap_type	2	type of vertical extrapolation for non-temperature variables; =1 : using the two lowest levels =2 : using the lowest level as a constant below ground	single entry
t_extrap_type	2	type of vertical extrapolation used for potential temperature; =1 : isothermal =2 : -6.5 K/km lapse rate for temp =3 : constant theta	single entry
use_maxw_level	0	when set to 1, real.exe uses input (from met_em* files) U, V, T, and GHT values at the level of max wind speed during vertical interpolation	single entry
maxw_horiz_pres_diff	5000	this value defines the maximum allowable pressure difference (in Pa) between adjacent values; when exceed use_maxw_level is set to 0 so that the level of maximum wind is not included in the column during real.exe vertical interpolation	single entry
maxw_above_this_level	30000	when use_maxw_level=1, max wind data will be used only for this pressure level, and those above (in height); e.g., if set to 3000 Pa, a max wind value at 5000 Pa is ignored; real-data simulations only	single entry
use_trop_level	0	when set to 1, real.exe uses input (from met_em* files) U, V, T, and GHT values at the tropopause level during vertical interpolation	single entry
trop_horiz_pres_diff	5000	this value defines the maximum allowable pressure difference (in Pa) between adjacent values; when exceeded, the tropopause level is excluded during real.exe vertical interpolation	single entry
use_tavg_for_tsk	.false.	when skin temperature is not present in input data, set this to .true. to use diurnally-averaged surface temperature (can be computed using WPS/util/avg_tsfc.exe) in place of skin temperature	single entry
use_sh_qv	.false.	when set to .true., real.exe uses specific humidity and mixing ratio from input data (met_em* files); this is recommended when input data have high vertical resolution	single entry
zap_close_levels	500	when \(\Delta p\) is less than this value, data from isobaric levels above the surface are ignored	single entry
rh2qv_wrt_liquid	.true.	computes qv with respect to liquid water; set to .false. to compute with respect to ice	single entry
rh2qv_method	1	the method used to compute mixing ratio from relative humidity (RH); =1 : old MM5 method =2 : WMO-recommended method (WMO- No. 49, corrigendum, August 2000)	single entry
vert_refine_method	0	the vertical refinement method used; =0 : no vertical refinement =1 : integer vertical refinement =2 : use specified or computed eta levels for vertical refinement	max_dom
vert_refine_fact	1	when using the ndown.exe program along with vertical refinement (vert_refine_method = 1 or 2), this is the vertical refinement factor used =1 : uses the same number of vertical levels as the coarse domain =2 : double the vertical resolution =3 : triple the vertical resolution =n : etc.	single entry

Specified Moving Nest Application

The following &domains record options are specific to the specified moving nest option, and can be used when WRF is configured/compiled with nesting option 2=preset-moves.

Note

Instead of a max_dom setting, some variables in this section use max_moves, which is set to 50 in the code. This can be modified in WRF/frame/module_driver_constants.F, and will be applied after WRF is recompiled to incorporate the change.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
num_moves	0	choose the total number of moves desired for the length of the simulation; each domain uses the same number of moves	single entry
move_id	(e.g.) 2, 2	this list of nested domain IDs sets the order for nests to move	max_moves
move_interval	(e.g.) 60, 120	the interval of time between the beginning of the simulation, to the time the nest moves	max_moves
move_cd_x move_cd_y	(e.g.) 1, -1	the i and j directions (respectively) that the parent domain moves for each move 1 : toward the east or north -1 : toward the west or south 0 : no move	max_moves

Vortex-following

The following &domains record options are specific to the Automatic Moving Nest (Vortex-following) option. To use these options, the model must be compiled with nesting option 3=vortex-following.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
vortex_interval	15	how often (in mins) a new vortex position is computed	max_dom
max_vortex_speed	40	used to compute the search radius for the new vortex position (in m/s)	max_dom
corral_dist	8	how close (in number of grid cells) the moving nest is allowed to get to the coarse grid boundary before the coarse grid moves	max_dom
track_level	50000	pressure level (in Pa) at which the tropical storm vortex is tracked	single entry
time_to_move	0	time (in mins from simulation start time) to start moving the nest	max_dom

Adaptive Time Step

The following &domains record options are specific to the Adaptive Time Step option.

Note

When use_adaptive_time_step=.true., the time_step setting in namelist.input is ignored and the below namelist options determine the time step.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
use_adaptive_time_step	.false.	set to .true. to turn on adaptive time step	single entry

The following options can be applied when use_adaptive_time_step=.true. :

step_to_output_time	.true.	as time_step adjusts, the time step and history write times don’t always align; set this to .true. to adjust the time and ensure they align	single entry
target_cfl	1.2	when vertical CFL \(\leq\) to this value, time step does not need to be reduced and is, instead, increased	max_dom
target_hcfl	0.84	when horizontal CFL \(\leq\) to this value, time step does not need to be reduced and is, instead, increased	max_dom
max_step_increase_pct	5	when time step is increased, this is the percent increase of the previous time step; use larger values for nests (e.g. = 5, 51, 51) time step increases when the max(vert CFL, horiz CFL) \(\leq\) target_cfl	max_dom
adaptation_domain	1	specifies the domain used to drive adaptive time stepping	single entry
starting_time_step	-1	any positive integer specifies the starting time step (in seconds); the default value (-1) sets the starting time step to \(4 \times DX\)	max_dom
starting_time_step_den	0	when a fractional time step is required, this is the starting_time_step denominator	max_dom
max_time_step	-1	any positive integer specifies the maximum time step (in seconds) that will be used; the default value (-1) sets the maximum time step to \(8 \times DX\)	max_dom
max_time_step_den	0	when a fractional time step is required, this is the max_time_step denominator	max_dom
min_time_step	-1	any positive integer specifies the minimum time step (in seconds) that will used; the default value (-1) sets the minimum time step to \(3 \times DX\)	max_dom
min_time_step_den	0	when a fractional time step is required, this is the min_time_step denominator	max_dom

Parallel Computing

The following &domains record options are specific to controlling parallel computing. WRF must have been compiled with a non-serial option for these options to be applicable.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
tile_sz_x tile_sz_y	0	number of points in the x and y directions to determine tile size for OpenMP processing	single entry
numtiles	1	number of tiles per patch for OpenMP processing; this is an alternative option to tile_sz_x and tile_sz_y	single entry
nproc_x nproc_y	-1	number of processors in the x and y directions for decomposition when using MPI processing; default value of -1 = off - code will use automatic decomposition	single entry

3D Ocean Model

The following &domains record options are specific to using the 3D Ocean Model, and can be applied when sf_ocean_physics=1 or 2.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
ocean_levels	30	number of ocean levels to use	single entry
ocean_z		the depth (in meters) of each ocean layer in its vertical profile; for e.g., if ocean_levels=30, ocean_z should have 30 settings; see WRF/run/README.namelist for details	max ocean_levels
ocean_t		the temperature (in K) for each ocean layer in its vertical profile; for e.g., if ocean_levels=30, ocean_t should have 30 settings; see WRF/run/README.namelist for details	max ocean_levels
ocean_s		the salinity for each ocean layer; for e.g., if ocean_levels=30, ocean_s should have 30 settings; see WRF/run/README.namelist for details	max ocean_levels

&physics

To use the options in this section, they must be set in the &physics namelist record.

Microphysics

See WRF Physics/Microphysics for details.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
mp_physics		microphysics scheme; set all domains to the same value; =0 : no microphysics =1 : Kessler scheme =2 : Purdue Lin scheme =3 : WSM 3-class ice scheme =4 : WSM 5-class scheme =5 : Ferrier (Eta) scheme =6 : WSM 6-class graupel scheme =7 : Goddard 4-ice scheme =8 : Thompson graupel scheme =9 : Milbrandt-Yau 2-moment scheme =10 : Morrison 2-moment =11 : CAM 5.1 5-class =13 : SBU_YLin 5-class =14 : WDM 5-class =15 : High-res Ferrier with advection =16 : WDM 6-class =18 : NSSL 2-moment 4-ice with predicted/unactivated or activated CCN; or “nssl_ccn_on=1”; also sets “ccn_conc” for mp_physics=18; see WRF/doc/README.NSSLmp for details =24 : WSM7; like WSM6, but with hail =26 : WDM7; like WDM6, but with hail =28 : aerosol-aware Thompson with water- and ice-friendly aerosol climatology; option to also set climatological aerosol input option “use_aero_icbs” - default is .false., (use constant values); set to .true. to use input from WPS =30 : HUJI spectral bin, fast version =38 : Thompson hail/graupel/aerosol =40 : Morrison double-moment with CESM aerosol (must be used with MSKF cumulus scheme) =50 : P3 1-ice category, 1-moment cloud water =51 : P3 1-ice category, 2-moment cloud water =52 : P3 2-ice categories, 2-moment cloud water =53 : P3 1-ice category, 3-moment ice, 2-moment cloud water; new since V4.3 =55 : Jensen ISHMAEL; new since V4.1 =56 : NTU multi-moment; new since V4.3	max_dom
do_radar_ref	0	set to 1 to compute radar reflectivity using mp-scheme-specific parameters works when mp_physics= 2,4,6,7,8,10,14,16,24, or 26; this option is automatically turned on when mp_physics=9 or 18, and when nwp_diagnostics=1	single input
mp_zero_out	0	set to 1 to keep moisture variables \(\geq\) 0; alternatively/recommended, use moist_adv_opt to maintain positive moisture variables;” =0 : no change to moisture fields =1 : all moisture arrays (except Qv) are set to zero if they fall below mp_zero_out_thresh (moist array only) =2 : all moisture arrays (including Qv) are set to zero if they fall below mp_zero_out_thresh (moist array only)	single input
mp_zero_out_thresh	1.e-8	the moisture variable threshold - moisture arrays are set to zero if they fall below this threshold; unit: kg/kg works when mp_zero_out >0	single input
mp_zero_out_all	0	set to 1 to reproduce old behavior and to extend the mp_zero_out_thresh to scalar, chem, and tracer arrays, in addition to moist arrays works when mp_zero_out >0	single entry
mp_tend_lim	10	the limitation (in K/s) of the temperature tendency computed by microphysics latent heating works when radar data assimilation is ued*	single input
ccn_conc	1.00E+08	the CCN concentration used; when mp_physics=18 this is automatically set to the nssl_ccn value works when mp_physics=14 or 16	single input
hail_opt	0	WSM6/WDM6 hail/graupel switch; =0 : graupel =1 : hail works when mp_physics=6 or 16	single input
morr_rimed_ice	1	Morrison hail/graupel switch; =0 : graupel =1 : hail works when mp_physics=10 or 40	single input
clean_atm_diag	0	set to 1 to turn on clean sky diagnostics works when using code compiled for WRF-chem	single input
acc_phy_tend	0	set to 1 to output 16 accumulated physics tendencies for potential temperature, water vapor mixing ratio, and u/v wind components works in WRFv4.4+	max_dom
progn	0	set to 1 to use a mix-activate scheme (see WRF/phys/module_mixactivate.F) works when mp_physics=10,14,16, or 18	max_dom
no_mp_heating	0	set to 1 to turn off microphysics latent heating	single entry
use_mp_re	1	option to use effective radii computed in the microphysics scheme works when ra_lw/sw_physics=4 and when mp_physics=3,4,6,7,8,10,14,16,18,24,26,28,50-53, or 55	single entry
dust_emis	0	set to 1 to use a surface dust emission scheme and add an ice-friendly aerosol variable (QNIFA) - see WRF/phys/module_dust_emis.F works when mp_physics=28	single entry
erosion_dim	3	set to 3 to include erodibility details; note that option 3 is the only available option works when dust_emis=1	single entry
write_thompson_mp38table	.false.	set to .true. to have the qr_acr_qg_mp38V1.dat file computed instead of using an existing version works when mp_physics=28	single entry
gsfcgce_hail	0	Goddard graupel/hail switch; =0 : graupel =1 : hail works when mp_physics=7	single input
gsfcgce_2ice	0	determines which frozen water particles are calculated by the Goddard microphysics scheme; =0 : snow, ice, and graupel/hail =1 : only ice and snow works when mp_physics=7	single input
nssl_cccn	0.5e9	the NSSL global base CCN concentration (#/m^3 at sea level pressure) works when mp_physics=18	single entry
nssl_ccn_on	-1	set to 1 to use NSSL CCN works when mp_physics=18	single entry

NSSL 1-moment scheme

The following &physics record settings are for the NSSL 1-moment microphysics scheme. Shape parameters can also be set for 1- and 2-moment schemes.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
nssl_alphah	0	shape parameter for graupel	max_dom
nssl_alphahl	1	shape parameter for hail	max_dom
nssl_cnoh	4.e5	graupel intercept	max_dom
nssl_cnohl	4.e4	hail intercept	max_dom
nssl_cnor	8.e5	rain intercept	max_dom
nssl_cnos	3.e6	snow intercept	max_dom
nssl_rho_qh	500	graupel density	max_dom
nssl_rho_ghl	900	hail density	max_dom
nssl_rho_qs	100	snow density	max_dom

Morrison-CESM Microphysics

The following &physics record options are specific to the Morrison+CESM microphysics scheme, and can be applied when mp_physics=40.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
aercu_opt	0	option to control aerosol interaction; =0 : no aerosol interaction =1 : aerosol interaction with only MSKF cumulus parameterization =2 : aerosol interaction with both MSKF cumulus parameterization and Morrison microphysics works when cu_physics=11 and when the CESM_RCP4.5_Aerosol_Data.dat file is available - once downloaded and unpacked, link or copy either of the two files to CESM_RCP4.5_Aerosol_Data.dat in the running directory prior to running wrf.exe	single entry
aercu_fct	1.0	the factor by which to multiply the aerosol amount	single entry
no_src_types_cu	1	an automatically-set number of aerosol species available in the global aerosol data being used (e.g., =10 for CESM input)	single entry
alevsiz_cu	1	an automatically-set number of levels available in the global aerosol data being used (e.g., =30 for CESM input)	single entry

Radiation Physics

The following options are set in the &physics namelist record. See Physics/Radiation for details.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
ra_lw_physics	-1	longwave radiation scheme; set all domains to the same value; =0 : no longwave radiation =1 : RRTM =3 : CAM; restarts must use 6-hourly intervals; works when using levsiz, paerlev, and cam_abs_dim1/2 namelist options =4 : RRTMG =5 : Goddard; updated in V4.1 =7 : FLG (UCLA) =14 : RRTMG-K; works when WRF is configured/compiled with -DBUILD_RRTMK = 1 (set in configure.wrf) =24 : fast RRTMG for GPU and MIC =31 : Earth Held-Suarez forcing =99 : GFDL (Eta); semi-supported; works when co2tf=1	max_dom
ra_sw_physics	-1	shortwave radiation scheme; set all domains to the same value; =0 : no shortwave radiation =1 : Dudhia; must use a ptop > 50mb =2 : old Goddard =3 : CAM; restarts must use 6-hourly intervals; works when using levsiz, paerlev, and cam_abs_dim1/2 namelist options =4 : RRTMG =5 : Goddard; updated in WRFv4.1 =7 : FLG (UCLA) =14 : RRTMG-K; works when WRF is configured/compiled with -DBUILD_RRTMK = 1 (set in configure.wrf) =24 : fast RRTMG for GPU and MIC =31 : Earth Held-Suarez forcing =99 : GFDL (Eta); semi-supported; works when co2tf=1	max_dom
radt	0	minutes between radiation physics calls; recommend 1 minute per km of dx (e.g., set to 10 for a 10 km grid); set all domains to the same value	max_dom
swint_opt	0	shortwave radiation interpolation option; =0 : off =1 : interpolate shortwave radiation based on the updated solar zenith angle between radiation calls =2 : activates FARMS to simulate the broadband solar radiation model every time step	single entry
couple_farms	.false.	set to .true. to drive the LSM using FARMS shortwave radiation; when .false., the ra_sw_physics scheme is used	single entry
ra_call_offset	0	option to offset the timing for radiation calls; =0 : no offset (radiation is called just after output) = -1 : calls radiation just before output time	single entry
co2tf	1	GFDL CO2 transmission function flag - CO2 function is generated internally works when ra_lw/sw_physics=99	single entry
cldovrlp	2	RRTMG cloud overlapping option; =1 : random =2 : maximum random =3 : maximum =4 : exponential =5 : exponential-random works when ra_lw/sw_physics=4 and with WRFv4.4+	single entry
idcor	0	decorrelation length calculation option; =0 : constant decorrelation length 2500 m =1 : latitude-varying decorrelation length works when cldovrlp=4 or 5 and with WRFv4.4+	single entry
ra_sw_eclipse	0	set to 1 to use an eclipse effect on shortwave radiation works when ra_sw_physics=1,2,4, or 5	single entry
ghg_input	1	option to read-in annual greenhouse gas values from CAMtr_volume_mixing_ratio files; =0 : no data read-in - use for backward compatibility in code prior to WRFv4.4 - uses constant values =1 : read in time-dependent data for CO2, N2O, CH4, CFC11, and CFC12; default is SSP 2 with RCP 4.5 -> SSP245; works when ra_lw_physics=1,2,4, or 24 and ra_sw_physics=3,4, or 24 and with WRFv4.4+	single entry
o3input	2	RRTMG ozone input option; =0 : use the profile from the RRTMG scheme =2 : use CAM ozone data (from the ozone.formatted” file found in WRFrun or WRF/test/em_real) works when ra_lw/sw_physics=4	single entry
aer_opt	0	RRTMG aerosol input option; =0 : off =1: use Tegen (1997) climatology =2 : use J. A. Ruiz-Arias method; see other aer_* options =3 : use Thompson water/ice-friendly climatological aerosol works when ra_lw/sw_physics=4	single entry
alevsiz	1	number of vertical levels in EC aerosol data; value is set automatically	single entry
no_src_types	1	number of aerosol species in Tegen global aerosol data; organic and black carbon, sea salt, sulfate, dust, and stratospheric aerosol (volcanic ash - currently 0); value is set automatically	single entry
use_rap_aero_icbc	.false.	set to .true. to read in real-time data containing aerosols works when mp_physics=28 and with WRFv4.4+	single entry
qna_update	0	set to 1 to update time-varying surface aerosol emissions from climatology or real-time data works when mp_physics=28, and when auxinput17_interval and io_form_auxinput17 are set in namelist.input; works with WRFv4.4+ must use input file wrfqnainp_d0*	single entry
wif_fire_emit	.false.	set to .true. to include organic and black carbon aerosols from biomass burning works when mp_physics=28 and with WRFv4.4+	single entry
wif_fire_inj	1	uses vertical distribution of emissions from biomass burning works when mp_physics=28 and with WRFv4.4+	max_dom
icloud	1	option for an optical depth cloud effect during radiation processing, where the option also determines cloud fraction options; =0 : no cloud effect =1 : Xu-Randall cloud effect; must use cloud fraction option 1 =2 : a 0/1 cloud effect, based on threshold; must use cloud fraction option 2 =3 : Sundqvist et al., 1989 cloud effect; must use cloud fraction option 3 works when ra_sw/lw_physics=1 or 4	single entry
insert_init_cloud	.false.	set to .true. to estimate the initial model cloud; cold start only works when icloud=3	single entry
swrad_scat	1	determines the amount of skattering; increase for more scattering works when ra_sw_physics=1	single entry
slope_rad	0	set to 1 to use slope effects for solar radiation	max_dom
topo_shading	0	set to 1 to use neighboring-point shadow solar radiation effects for shortwave radiation	max_dom
shadlen	25000	max length (in meters) of orographic shadows works when topo_shading=1	single entry

Aerosol Options

The following aerosol options are specific to RRTMG (ra_lw/sw_physics=4) and new Goddard (ra_lw/sw_physics=5) radiation to recognize the aerosol option setting, but the aerosols are constant during model integration. These options are set in the &physics namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
aer_aod550_opt	1	input option for aerosol optical depth (AOD) at 550 nm; =1 : input constant value from namelist option aer_aod550_val =2 : input value from auxiliary input 15 - a time-varying 2d grid in netCDF format	max_dom
aer_aod550_val	0.12	fixed value for aerosol optical depth at 550 nm works when aer_aod550_opt=1	max_dom
aer_angexp_opt	1	input option for aerosol Angstrom exponent; =1 : input constant value from namelist option aer_angexp_val =2 : input value from auxiliary input 5 - a time-varying 2d grid in netCDF format =3 : value estimated from the aerosol type defined in aer_type and modulated with RH in WRF	max_dom
aer_angexp_val	1.3	fixed value for aerosol Angstrom exponent works when aer_angexp_opt=1	max_dom
aer_ssa_opt	1	input option for aerosol single scattering albedo; =1 : input constant value from namelist option aer_ssa_val =2 : input value from auxiliary input 5 - a time-varying 2d grid in netCDF format =3 : value estimated from the aerosol type defined in aer_type and modulated with RH in WRF	max_dom
aer_ssa_val	0.85	fixed value for aerosol single scattering albedo works when aer_ssa_opt=1	max_dom
aer_asy_opt	1	input option for the aerosol asymmetry parameter; =1 : input constant value from namelist option aer_asy_val =2 : input value from auxiliary input 5 - a time-varying 2d grid in netCDF format =3 : value estimated from the aerosol type defined in aer_type and modulated with RH in WRF	max_dom
aer_asy_val	0.90	fixed value for the aerosol asymmetry parameter works when aer_asy_opt=1	max_dom
aer_type	1	aerosol type for the above aer* options; =1 : rural =2 : urban =3 : maritime	max_dom

CAM Radiation

The following CAM radiation options are automatically set by default, but for modifications, they should be set in the &physics namelist record. These options are applied when ra_lw/sw_physics=3.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
cam_abs_freq_s	21600	the frequency (in seconds) at which clear sky longwave absorption is calculated; 21600 is the recommend minimum to speed-up CAM processing	single entry
levsiz	1	the number of ozone data levels	single entry
paerlev	1	the numer of aerosol data levels	single entry
cam_abs_dim1	1	the dimension for the absorption save array (absnxt) variable found in the CAM code (see WRF/phys/module_ra_cam.F)	single entry
cam_abs_dim2	1	the dimension for the 2nd absorption save array (abstot) variable found in the CAM code (see WRF/phys/module_ra_cam.F)	single entry

Surface Physics

See WRF Physics/Surface Physics. for details. These options are set in the &physics namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
sf_sfclay_physics		surface layer physics scheme; set all domains to the same value; =0 : no surface layer physics =1 : revised MM5 Monin-Obukhov =2 : Monin-Obukhov (Janjic Eta Similarity) =4 : QNSE =5 : MYNN =7 : Pleim-Xiu; works with sf_surface_physics=7 and bl_pbl_physics=7 =10 : TEMF =91 : old MM5	max_dom
iz0tlnd	0	the method for determining land thermal roughness length; =0 : non-vegetation-dependent thermal roughness length over land =1 : vegetation dependent (see Chen and Zhang, 2009)	single entry
sf_surface_physics		land surface scheme option; note this setting is used during real.exe processing; set all domains to the same value; =0 : no surface temperature prediction =1 : 5-layer thermal diffusion (SLAB) =2 : unified Noah =3 : RUC =4 : NoahMP; see additional &noah_mp options =5 : CLM4 =7 : Pleim-Xiu; works when sf_sfclay_physics=7 and bl_pbl_physics=7 =8 : SSiB; works when ra_lw/sw_physics=1,3, or 4	max_dom
sf_urban_physics	0	activates and determines the urban canopy model scheme; set all domains to the same value; =0 : off =1 : single-layer, UCM =2 : multi-layer, building environment parameterization (BEP); works with bl_pbl_physics=1,2, or 8 =3 : multi-layer, building environment model (BEM); works with bl_pbl_physics=1,2, or 8 works when sf_surface_physics=2	max_dom
use_wudapt_lcz	0	set to 1 to use WUDAPT LCZ urban landuse categories (31-41) - instructions for creating LCZ data; when set to 0, the traditional (31-33) urban categories are used	single entry
slucm_distributed_drag	.false.	set to .true. to use spatially-varying 2D urban zero-plane displacement, roughness length for momentum, and frontal area index (see additional details and requirements) works when urban_physics=1 does not work when use_wudapt_lcz=1	single entry
distributed_ahe_opt	0	method used for anthropogenic surface heat flux (see additional details and requirements); =0 : do not use anthropogenic surface heat flux from the input data =1 : add to the first level temperature tendency =2 : add to surface sensible heat flux	single entry
ua_phys	.false.	set to .true. to activate UA Noah LSM changes for an alternate snow-cover that is aimed to improve treatment of snow as it relates to the vegetation canopy; also uses different VEGPARM.TBL columns	single entry
num_soil_layers	5	the number of soil layers available in land surface model used; this option is read by real.exe; =2 : Pleim-Xiu =3 : SSiB =4 : Noah =5 : thermal diffusion scheme for temperature only =6 or =9 : RUC =10 : CLM4	single entry
ideal_xland	1	determines whether land mask (XLAND) is set to land (=1) or water (=2) for idealized cases with no input land-use run-time switch during wrf.exe physics initialization; =1 : land =2 : water	single entry
ifsnow	1	turns on SLAB snow-cover effects (set to 0 to turn off) works when sf_surface_physics=1	single entry
surface_input_source	3	the source from which landuse and soil category originate; =1 : WPS/geogrid, but with dominant categories recomputed in real =2 : GRIB data from another model; only if VEGCAT/SOILCAT exist =3 : use dominant land and soil categories from WPS/geogrid	single entry
pxlsm_smois_init	1	Pleim-Xiu LSM soil moisture initialization method; =0 : from analysis =1 : from moisture availability (SLMO in the LANDUSE.TBL) works when sf_surface_physics=7	max_dom
num_land_cat	21	the number of land categories from geographical input data; =20 : MODIS =21 : MODIS with lake category included (default in WPS) =24 : USGS =28 : USGS with lake category included =40 : NLCD2006 - North America only	single entry
num_soil_cat	16	number of soil categories available from the input data	single entry
usemonalb	.false.	set to .true. to use a 2D climatological monthly albedo map instead of table values (.TBL files in WRF/test/em_real), which is recommended when sst_update=1	single entry
rdmaxalb	.true.	determines source for snow albedo; =.true. : from geogrid =.false. : from table values (.TBL files in WRF/test/em_real)	single entry
rdlai2d	.false.	set to .true. to use leaf area index (LAI) from input data, instead of from table values (.TBL files in WRF/test/em_real); when sst_udpate=1, LAI is included in the real.exe-generated wrflowinp_d0* file	single entry
sst_update	0	set to 1 to turn on time-varying sea-surface temperature, seaice, vegetation fraction, and albedo; set before running real.exe; real.exe creates wrflowinp_d0* file(s) that include SST, XICE, ALBEDO, and VEGFRA - during wrf.exe these are updated at the same interval as the wrfbdy_d01 file works when auxinput4_interval, auxinput4_end_h, io_form_auxinput4, and auxinput4_inname=”wrflowinp_d<domain>” are set in the &time_control namelist record*	single entry
tmn_update	0	set to 1 to update deep layer soil temperature; useful for long (multi-year) simulations	single entry
lagday	150	number of days over which TMN (deep layer soil temperature) is computed using skin temperature	single entry
sst_skin	0	set to 1 to calculate skin SST; useful for long (multi-year) simulations	single entry
shalwater_z0	0	set to 1 to turn on a shallow water roughness scheme works when sf_sfclay_physics=1 and when required bathymetry data has been computed in WPS works with WRFv4.4+	max_dom
shalwater_depth	-1.0	option to set constant depth (in meters) when shalwater_z0=1 and no bathymetry data is available; intended for depths between 10.0 and 100.0 m; depths outside this range are rounded to the nearest limit value works with WRFv4.4+	single entry

Surface Irrigation Parameterization

The following options are specific to surface irrigation parameteriation and are only applicable when sf_surf_irr_scheme>0 and in WRFv4.2+. These options are set in the &physics namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
sf_surf_irr_scheme	0	surface irrigation scheme option; =0 : off =1 : surface evapotranspiration; works when sf_surface_physics=2 =2 : leaves/canopy interception and surface evapotranspiration =3 : microphysics process, leaves/canopy interception and surface evapotranspiration	max_dom
irr_daily_amount	0	the amount per day (mm/day) of irrigation water applied	max_dom
irr_start_hour	0	the UTC start hour for irrigation	max_dom
irr_num_hours	0	the total number of hours to apply irrigation	max_dom
irr_start_julianday	0	the Julian day to start irrigation (this start time is included in the total time)	max_dom
irr_end_julianday	0	the Julian day to end irrigation (this end time is not included in the total time)	max_dom
irr_freq	1	irrigation frequency (in days)	max_dom
irr_ph	0	irrigation phase; =0 : in phase =1 : not in phase	max_dom

Planetary Boundary Layer Physics

See WRF Physics/PBL for details. These options are set in the &physics namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
bl_pbl_physics		boundary layer physics scheme; set all domains to the same value (except when running an LES simulation); =0 : no boundary layer =1 : YSU; works when sf_sfclay_physics=1 =2 : MYJ (Eta) TKE; works when sf_sfclay_physics=2 =4 : QNSE-EDMF; works when sf_sfclay_physics=4 =5 : MYNN 2.5 level TKE; works when sf_sfclay_physics=1,2, or 5 =6 : MYNN 3rd level TKE; works when sf_sfclay_physics=5 =7 : ACM2 (Pleim); works when sf_sfclay_physics=1 or 7 =8 : BouLac TKE; works when sf_sfclay_physics=1 or 2 =9 : Bretherton-Park/UW TKE; works when sf_sfclay_physics=1 or 2 =10 : TEMF; works when sf_sfclay_physics=10 =11 : Shin-Hong “scale-aware” =12 : GBM TKE; works when sf_sfclay_physics=1 =16 : EEPS; works when sf_sfclay_physics=1,5, or 91 =17 : KEPS =99 : MRF	max_dom
mfshconv	1	turns on the QNSE mass flux scheme; set to 0 to turn off	max_dom
bldt	0	minutes between boundary-layer physics calls & processing; 0 (call every time step) is recommended; set all domains to the same value	max_dom
topo_wind	0	YSU topographic surface wind correction option; these options work when bl_pbl_physics=1 =0 : off =1 : Jimenez method; requires extra input from geogrid; =2 : UW method	single entry
tke_budget	0	set to 1 to add MYNN TKE budget terms to output works when bl_pbl_physics=5 works with WRFv4.5+; use bl_mynn_tkebudget in WRF versions < v4.5	max_dom
bl_mynn_tkeadvect	.false.	set to .true. to use MYNN TKE advection to couple subgrid-scale clouds from the MYNN PBL scheme, to the longwave and shortwave radiation schemes works when bl_pbl_physics=5	max_dom
bl_mynn_cloudmix	1	turns on MYNN cloud water (qc) and cloud ice (qi) mixing; cloud water droplet number (qnd) and cloud ice number concentation (qni) are mixed when scalar_pblmix=1 works when bl_pbl_physics=5	max_dom
bl_mynn_mixlength	1	option to change the MYNN mixing length calculation; =0 : original; as in Nakanishi and Niino, 2009 =1 : RAP/HRRR; including BouLac in free atmosphere =2 : experimental; includes cloud-specific mixing length and a scale-aware mixing length; following Ito et al., 2015, BLM; this option is well-tested with EDMF options works when bl_pbl_physics=5	single entry
bl_mynn_cloudpdf	2	MYNN option to use alternate cloud PDFs to represent subgrid clouds; =0 : original; Sommeria and Deardorff, 1977 =1 : Kuwano et al., 2010; similar to option 0, but uses resolved scale gradients, as opposed to higher order moments =2 : Chaboureau and Bechtold, 2002, with mods works when bl_pbl_physics=5	single entry
bl_mynn_edmf	1	option to activate the MYNN mass-flux scheme; =0 : regular MYNN =1 : for StEM =2 : for TEMF works when bl_pbl_physics=5	max_dom
bl_mynn_edmf_mom	1	activates MYNN momentum transport (set to 0 to turn off) works when bl_pbl_physics=5 and bl_mynn_edmf>0	max_dom
bl_mynn_edmf_tke	0	set to 1 to activate MYNN TKE transport works when bl_pbl_physics=5 and bl_mynn_edmf>0	max_dom
scalar_pblmix	0	set to 1 to mix 4d scalar variables to be consistent with the PBL option (exch_h)	max_dom
tracer_pblmix	1	mixes tracer fields to be consistent with the PBL option (exch_h); set to 0 to turn off	max_dom
shinhong_tke_diag	1	activates Shin-Hong PBL diagnostic TKE and mixing length works when bl_pbl_physics=11	max_dom
opt_thcnd	1	how Noah LSM thermal conductivity is handled; =1 : original =2 : McCumber and Pielke for silt loam and sandy loam works when sf_surface_physics=2	single entry
sf_surface_mosaic	0	set to 1 to use Noah LSM mosaic landuse subtiling works when sf_surface_physics=2	single entry
mosaic_cat	3	number of mosaic landuse categories in a grid cell when sf_surface_mosaic=1	single entry
mosaic_lu	0	set to 1 to specify landuse parameters based on a mosaic approach works whensf_surface_physics=3	single entry
mosaic_soil	0	set to 1 to specify soil parameters based on a mosaic approach works whensf_surface_physics=3	single entry
grav_settling	0	gravitational settling of fog/cloud droplets; =0 : no settling =1 : Dyunkerke, 1991 atmospheric and surface settling =2 : use Fogdes vegetation and wind speed dependent (Katata et al., 2008) at the surface, and Dyunkerke for the atmosphere	max_dom
ysu_topdown_pblmix	1	turns on top-down radiation-driven mixing	single entry
isfflx	1	when bl_pbl_physics >0, this determines whether surface heat and moisture fluxes are used; =0 : fluxes not used =1 : fluxes used when bl_pbl_physics=0, diff_opt=2, and km_opt=3, this determines how surface fluxes are calculated =0 : constant fluxes defined by namelist options tke_drag_coefficient and tke_heat_flux =1 : uses heat and moisture fluxes, along with model-computed u* =2 : uses model-computed u*, along with heat flux specified by namelist option tke_heat_flux works for real-data cases when sf_sfclay_physics=1,5,7, or 11	single entry

Cumulus Parameterization

See WRF Physics/Cumulus Parameterization for details. These options are set in the &physics namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
cu_physics		cumulus parameterication scheme; set all domains to the same value, unless turning cumulus parameterization off for some domains; =0: no cumulus =1 : Kain-Fritsch (new Eta) =2 : BMJ =3 : Grell-Freitas ensemble =4 : Scale-aware GFS SAS =5 : Grell-3 =6 : Tiedtke =7 : CESM’s Zhang-McFarlane; works when bl_pbl_physics=2 or 9 =10 : KF-CuP; modified Kain-Fritsch with trigger function based on PDFs =11 : Multi-scale Kain-Fritsch (with momentum transport in WRFv4.2+) =14 : Scale-aware SAS; works when shcu_physics=4 =16 : Newer Tiedtke =93 : Grell-Devenyi ensemble =96 : GFS SAS from YSU (previously option 14) =99 : old Kain-Fritsch	max_dom
bmj_rad_feedback	.false.	set to .true. to use the BMJ radiative cloud effect - a convective precipitation-derived sub-grid cloud effect works with WRFv4.2+	max_dom
cudt	0	minutes between cumulus physics calls and processing; =0 (call every time step) is recommended with all cu_physics options except Kain-Fritsch (cu_physics=1,10,11, or 99); set all domains to the same value	max_dom
kfeta_trigger	1	Kain-Fritsch option that determine whether a grid point is convective; =1 : original =2 : moisture-advection-based trigger (Ma and Tan, 2009) =3 : relative humidity-dependent works when cu_physics=1	single entry
ishallow	0	set to 1 to turn on shallow convection; works when cu_physics=3 or 5	single entry
cu_diag	0	set to 1 to compute time-averaged surface rainfall and cloud water/ice works when WRF is built for use with WRF-Chem and when cu_physics=3,5, or 93	max_dom
shcu_physics	0	shallow cumulus scheme, independent of deep convection from cu_physics; =0 : no independent shallow cumulus =2 : Park and Bretherton, from CAM5 =3 : GRIMS 5 : Deng; works when bl_pbl_physics=2,5, or 6 and with WRFv4.1+	max_dom
cugd_avedx	1	number of grid boxes over which subsidence is spread; =1 : for large grid distances (low resolution) =3 : for small grid distances (DX < 5km) works when cu_physics=5	single entry
nsas_dx_factor	0	set to 1 to use the NSAS grid-distance-dependent option	single entry
kf_edrates	0	set to 1 to output entrainment/detrainment rates and convective timescale output variables for KF-based cumulus schemes works when cu_physics=1,11, or 99	max_dom
convtrans_avglen_m	30	averaging time (in mins) for convective transport output variables works when cu_physics=3,5, or 93	single entry
cu_rad_feedback	.false.	set to .true. to have the cumulus/sub-grid cloud effect fed back to the radiation scheme’s optical depth works when cu_physics=1,3,5,10,11,93, or 99 when cu_physics=3,5, or 93, then cu_diag=1 must also be set	max_dom

The following options related to cumulus parameterization show recommended values. Consult the code to use other values. These options are set in the &physics namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
maxiens	1	works when cu_physics=3,5,93	single entry
maxens	3	works when cu_physics=3,5,93	single entry
maxens2	3	works when cu_physics=3,5,93	single entry
maxens3	16	works when cu_physics=3,5,93	single entry
ensdim	144	works when cu_physics=3,5,93	single entry

KF-CuP Cumulus Parameterization

The following options are specific to the KF-CuP cumulus parameterization scheme (cu_physics=10). These options are set in the &physics namelist record.

Note

These options are recommended to be used with cu_rad_feedback=.true.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
shallowcu_forced_ra	.false.	set to .true. to force a radiative impact of shallow cumulus by a max cloud fraction of 0.36	max_dom
numbins	1	the number of potential temperature and mixing ratio bins/perturbations used in the CuP PDF; set to an odd number - the recommended value is 21	max_dom
thBinSize	1	the size of PDF theta (potential temperature perturbation increment - 0.01 K) bins	max_dom
minDeepFreq	1	minimum frequency required before deep convection is allowed (0.333)	max_dom
minShallowFreq	1	minimum frequency required before shallow convection is allowed (1.0e-2)	max_dom
shcu_aerosols_opt	0	set to 2 to include aerosols in the shallow cumulus scheme works when WRF is compiled with WRF-Chem capability	max_dom

Ocean Model Physics

The following options are specific to ocean model physics and are set in the &physics namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
sf_ocean_physics	0	option to use an ocean model physics scheme; =0 : off =1 : simple ocean mixed layer (OML) model =2 : 3D Price-Weller-Pinkel (PWP) ocean model	single entry
oml_hml0	50	the OML initial mixed layer depth; =0 : from climatology >0 : constant everywhere (in meters) <0 : use input from the ocean model works when sf_ocean_physics=1	single entry
oml_gamma	0.14	OML deep water (below the mixed layer) lapse rate (\(\frac {K}{m}\)) works when sf_ocean_physics=1	single entry
oml_relaxation_time	0	OML relaxation time (in seconds) back to original values; e.g., a setting of 259200 seconds = 3 days works when sf_ocean_physics=1	single entry
omdt	1	the PWP ocean model time step (in mins); can be the same as the WRF time step (time_step), but should be \(\geq\) 1.0 minute works when sf_ocean_physics=2	single entry
ocean_levels	30	PWP number of vertical levels works when sf_ocean_physics=2	single entry

Seaice

The following options are specific to seaice. These options are set in the &physics namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
seaice_threshold	100	in grids where skin temperature (TSK, in K)) is < this value, water points are changed to sea ice; a) if sf_surface_physics=1, those water points are changed to land points with permanent ice b) if sf_surface_physics=2, those water points are changed to land points with permanent ice, and 2m temperature values are used for surface temperature; soil moisture (smois) and soil liquid water (sh2o) are also applied works when sf_surface_physics=1,2,3,4, or 8	single entry
fractional_seaice	0	set to 1 to treat seaice as a fractional field when using fractional seaice data input (see details) works when sf_sfclay_physics=1,2,3,4,5,7, or 91 and when seaice_threshold=0	single entry
seaice_albedo_opt	0	determines how albedo is calculated over sea ice; =0 : a constant value from namelist option seaice_albedo_default =1 : a function of air temperature, skin temperature, and snow =2 : uses seaice albedo input variable (ALBSI)	single entry
seaice_albedo_default	0.65	seaice albedo value used when seaice_albedo_opt=0	single entry
seaice_snowdepth_opt	0	method for calculating snow depth (SNOWH) on seaice; =0 : bounded by seaice_snowdepth_min and seaice_snowdepth_max namelist settings; =1 : uses seaice snow depth input variable (SNOWSI), and is bounded by seaice_snowdepth_min and seaice_snowdepth_max namelist settings	single entry
seaice_snowdepth_min	0.001	minimum snow depth (in meters) on sea ice used for the terms specified for seaice_snowdepth_opt above	single entry
seaice_snowdepth_max	1.e10	maximum allowed snow depth (in meters) on sea ice used for the terms specified for seaice_snowdepth_opt above	single entry
seaice_thickness_opt	0	method for calculating seaice thickness; =0 : uniform value taken from namelist option seaice_thickness_default =1 : uses seaice thickness input variable (ICEDEPTH)	single entry
seaice_thickness_default	3.0	seaice thickness value used when seaice_thickness_opt=0	single entry

Lake Model

The following options are specific to the lake model (sf_lake_physics=1) and are set in the &physics namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
sf_lake_physics	0	set to 1 to turn on the lake model	max_dom

Note

The following options work when sf_lake_physics=1.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
lakedepth_default	50	lake depth (in meters); 50 m is the depth used when no lake depth data is included in the input data; otherwise, set according to input data	max_dom
lake_min_elev	5	minimum elevation of lakes; if the geographical static input do not include a lake category, this is used to determine whether a water point is should be set to a lake point	max_dom
use_lakedepth	1	option to use lake depth data generated by the geogrid program; set to 0 to turn off	max_dom

Lightning Parameterization

The following options are specific to lightning parameterization (when lightning_option \(\geq\) 1) These options are set in the &physics namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
lightning_option	0	lightning parameterization for predicting flash rate without chemistry; =0 : off =1 : PR92, based on maximum vertical motion (w) =2 : PR92, based on a 20 dBZ top - when dBZ > 20 flashes are redistributed (in convection-resolved simulations) =3 : uses the Yair et al., 2010 method to predict the potential for lightning activity =11 : PR92, based on neutral buoyancy derived from the convective parameterization scheme; intended for grid resolution 10 < dx < 50km works when do_radar_ref=1	max_dom
lightning_dt	0	time interval (in seconds) for how often lightning parameterization is called/processed; if left as =0, the standard time_step namelist setting is used	max_dom
lightning_start_seconds	0	the number of seconds from the simulation start time, until lightning parameterization is first processed; recommended to allow a model spin-up for at least 10 minutes	max_dom
flashrate_factor	1.0	factor used to adjust the predicted number of flashes; recommended values: a) when lightning_option=11 and \(10000 \leq dx \geq 50000\) b) when lightning_option=1,2, or 3, manual tuning is used	max_dom
cellcount_method	0	method used to count storm cells; =0 : model-determined method =1 : tile-wide; appropriate for large domains =2 : domain-wide; appropriate for single storm domains works when lightning_option=1 or 2	max_dom
cldtop_adjustment	0	cloud top adjustment from LNB (in km); recommended setting is =2 (2 km) works when lightning_option=11	max_dom
iccg_method	0	intra-cloud (IC) : cloud-to-ground (CG) partitioning method; =0 : if set to 0, this is automatically set to 2 (below) =1 : constant everywhere; works when *iccg_prescribed_num and iccg_prescribed_den namelist variables are set; all CG =2 : coarsely-prescribed 1995-1999 NLDN/OTD climatology, based on Boccippio et al., 2001 =3 : Price and Rind, 1993 method based on cold-cloud depth =4 : monthly mapped ratios are calculated using iccg_in_num and iccg_in_den from the wrfinput_d0* file; for points with 0/0 values, the ratio is defined by iccg_prescribed_num and iccg_prescribed_den namelist settings	max_dom
iccg_prescribed_num	0.0	numerator of the user-specified prescribed IC:CG	max_dom
iccg_prescribed_den	1.0	denominator of the user-specified prescribed IC:CG	max_dom

Wind Turbine Drag Parameterization

The following options are specific to the wind turbine drag parameterization (when windfarm_opt \(\geq\) 1). These options are set in the &physics namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
windfarm_opt	0	wind turbine drag parameterization; =0 : off =1 : activates Fitch et al., 2012 wind farm parameterization and simulates the effects of wind turbines in atmospheric evolution =2 : Activates the Ma et al., 2022 wind farm scheme, which is similar to option 1, but it also considers subgrid-scale wind turbine wake effects; works in combination with windfarm_wake_model and windfarm_overlap_method, as well as with a file “windturbines-ll.txt”	max_dom
windfarm_ij	0	the type of wind turbine location coordinate used; =0 : turbine coordinates are defined in terms of lat-lon =1 : turbine coordinates are defined in terms of grid points (i,j) =2 : turbine coordinates are defined in terms of lat-lon in a user-created file named windturbines-ll.txt; works when windfarm_wake_model=2	single entry
windfarm_wake_model	2	subgrid-scale wind turbine wake model; =1 : Jensen model =2 : XA model =3 : GM model (windfarm_method not used) =4 : Jensen and XA ensemble =5 : Jensen, XA, and GM ensemble works when windfarm_opt=2	max_dom
windfarm_overlap_method	4	wake superposition method for the Jensen and XA wind turbine wake model (windfarm_wake_model=4); works when windfarm_opt=2 =1 : linear superposition =2 : squared superposition =3 : modified squared superposition =4 : superposition of the hub-height wind speed (Ma et al., 2022)	max_dom
windfarm_deg	0	the wind farm layout’s degree of rotation works windfarm_opt=2 and windfarm_ij=1	max_dom

Hailcasting

The following options are specific to hailcasting (when hailcast_opt=1), and are set in the &physics namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
hailcast_opt	0	set to 1 to turn on hailcasting	max_dom
haildt	0	seconds between WRF-HAILCAST call(s) works when hailcast_opt=1	max_dom

Miscellaneous Physics Options

These options are set in the &physics namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
bucket_mm	-1	for accumulating water variables, this is the bucket capacity (in mm) before it is emptied and accumulation starts over; setting this may prevent significant digit computation issues when performing averaging on these variables; useful for long (months - multi-year) simulations; default value -1 means this option is not activated; (details)	single entry
bucket_j	-1	for accumulating energy variables, this is the bucket capacity (in Joules) before it is emptied and accumulation starts over; setting this may prevent significant digit computation issues when performing averaging on these variables; useful for long (months - multi-year) simulations; default value -1 means this option is not activated; (details)	single entry
isftcflx	0	option to use alternative (to the default) calculations for Ck (exchange coefficient for temperature and moisture) and Cd (drag coefficient for momentum) with tropical storm application; =0 : Ck is off =1 : Donelan Cd + constant Z0q for Ck =2 : Donelan Cd + Garratt Ck	single entry
traj_opt	0	set to 1 to activate forward trajectories, calculated as in Lee and Chen, 2013 single entry
num_traj	1000	the number of trajectories released when traj_opt=1	single entry

&stoch

The options in this section are set in the &stoch namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
nens	1	a seed for a random number stream; the seed is a function of the initial start time, ensuring different random number streams are generated when forecasts start at different times; changing this seed changes the random number streams for all activated stochastic parameterization schemes; the setting should be different for each member for ensemble forecasts	single entry

Stochastic Kinetic-energy Backscatter Scheme (SKEBS)

The following options are specific to the Stochastic Kinetic-energy Backscatter Scheme (SKEBS), and work when skebs=1. These options are set in the &stoch namelist record.

See also

See details about the SKEBS option

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
skebs	0	set to 1 to turn on the stochastic kinetic-energy backscatter scheme (SKEBS)	max_dom
tot_backscat_psi	1.0e -05	total backscattered dissipation rate for streamfunction; controls the amplitude of rotational wind perturbations (in m 2/s 2)	max_dom
tot_backscat_t	1.0e -06	total backscattered dissipation rate for potential temperature; controls the amplitude of potential temperature perturbations (in m 2/s 2)	max_dom
ztau_psi	10800.0	decorrelation time (in seconds) for streamfunction perturbations	single entry
ztau_t	10800.0	decorrelation time (in seconds) for potential temperature perturbations	single entry
rexponent_psi	-1.83	spectral slope for streamfunction perturbations; -1.83 is default for a kinetic-energy forcing spectrum with a slope of -5/3)	single entry
rexponent_t	-1.83	spectral slope for potential temperature perturbations; -1.83 is default for a potential energy forcing spectrum with a slope of -1.832)	single entry
kminforc	1	minimal forcing wavenumber in longitude for streamfunction (psi) perturbations	single entry
lminforc	1	minimal forcing wavenumber in latitude for streamfunction (psi) perturbations	single entry
kminforct	1	minimal forcing wavenumber in longitude for potential temperature (theta) perturbations	single entry
lminforct	1	minimal forcing wavenumber in latitude for potential temperature (theta) perturbations	single entry
kmaxforc	1000000	maximum forcing wavenumber in longitude for streamfunction (psi) perturbations; the default is the maximum possible wavenumbers, determined by the number of gridpoints in longitude	single entry
lmaxforc	1000000	maximum forcing wavenumber in latitude for streamfunction (psi) perturbations; the default is the maximum possible wavenumbers, determined by the number of gridpoints in latitude	single entry
kmaxforct	1000000	maximum forcing wavenumber in longitude for potential temperature (theta) perturbations; the default is the maximum possible wavenumbers, determined by the number of gridpoints in longitude	single entry
lmaxforct	1000000	maximum forcing wavenumber in latitude for potential temperature (theta) perturbations; the default is the maximum possible wavenumbers, determined by the number of gridpoints in latitude	single entry
zsigma2_eps	0.0833	noise variance in the autoregressive process that defines streamfunction perturbations	single entry
zsigma2_eta	0.0833	noise variance in the autoregressive process that defines potential temperature perturbations	single entry
skebs_vertstruc	0	defines the vertical structure of the random pattern generator; =0 : constant vertical structure of the random pattern generator =1 : random phase vertical structure with westward tilt	single entry
iseed_skebs	811	seed for the random number stream for skebs; this is combined with seed nens, signifying ensemble member number and initial start time to ensure different random number streams for forecasts starting from different times and for different ensemble members	single entry

Stochastic Kinetic-Energy Backscatter Scheme (SKEBS)

The following options are specific to the Stochastic Kinetic-Energy Backscatter Scheme (SKEBS) used to perturb a forecast, and work when skebs=1 and rand_perturb=1. These options are set in the &stoch namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
rand_perturb	0	set to 1 to create a random perturbation field	max_dom
lengthscale_rand_pert	500000	perturbation correlation lengthscale (in meters)	max_dom
timescale_rand_pert	21600.0	temporal decorrelation of the random field (in seconds)	max_dom
gridpt_stddev_rand_pert	0.03	standard deviation of the random perturbation field at each grid point	max_dom
stddev_cutoff_rand_pert	3.0	cutoff tails of the pdf perturbation pattern above this threshold standard deviation	max_dom
rand_pert_vertstruc	0	vertical structure type for the random perturbation field; =0 : constant =1 : random phase with tilt	single entry
iseed_rand_pert	17	seed for the random number stream; this is combined with seed nens, signifying ensemble member number and initial time to ensure different random number streams are created for forecasts starting from different times and for different ensemble members	single entry

Stochastically-perturbed Physical Tendencies (SPPT)

The following options are specific to the Stochastically-perturbed Physical Tendencies (SPPT), and work when sppt=1. These options are set in the &stoch namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
sppt	0	set to 1 to turn on stochastically-perturbed physics tendences (SPPT)	max_dom
lengthscale_sppt	150000	random perturbation lengthscale (in meters)	max_dom
timescale_sppt	21600	temporal decorrelation of the random field (in seconds)	max_dom
sppt_vertstruc	0	SPPT vertical structure type; =0 : constant =1 : random phase	single entry
gridpt_stddev_sppt	0.5	standard deviation of the random perturbation field at each grid point	max_dom
stddev_cutoff_sppt	2.0	cutoff tails of the pdf perturbation pattern above this threshold standard deviation	max_dom
iseed_sppt	53	seed for the SPPT random number stream; this is combined with parameter nens, signifying ensemble member number and initial time to ensure different random number streams for forecasts starting from different times and for different ensemble members	single entry

Stochastically-perturbed Parameter Scheme (SPP)

The following options are specific to the Stochastically-perturbed Parameter Scheme (SPP), and work when spp=1. These options are set in the &stoch namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
spp	0	set to 1 to turn on the stochastically-perturbed parameter scheme (SPP) works when cu_physics=3, bl_pbl_physics=5 or 6, and/or sf_surface_physics=3	max_dom

Note

The following subset of options are specific to Grell Freitas convective parameterization - they work when spp=1 and cu_physics=3.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
spp_conv	0	set to 1 to turn on perturbation of Grell Freitas (GF) convective parameters	max_dom
lengthscale_spp_conv	150000	perturbation length scale (in meters) for GF convection	max_dom
timescale_spp_conv	21600	temporal decorrelation of the random field (in seconds)	max_dom
gridpt_stddev_spp_conv	0.3	standard deviation of the random perturbation field at each grid point	max_dom
stddev_cutoff_spp_conv	3.0	cutoff tails of the pdf perturbation pattern above this threshold standard deviation	max_dom
vertstruc_spp_conv	1	vertical structure type for random perturbation; =0 : constant =1 : random phase	single entry
iseed_spp_conv	171	seed for the random number stream for spp_conv	single entry

Note

The following subset of options are specific to the MYNN PBL scheme - they work when spp=1 and bl_pbl_physics=5 or 6.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
spp_pbl	0	set to 1 to turn on perturbation of MYNN PBL parameters	max_dom
lengthscale_spp_pbl	700000.0	perturbation length scale (in meters)	max_dom
timescale_spp_pbl	21600.0	temporal decorrelation of the random field (in seconds)	max_dom
gridpt_stddev_spp_pbl	0.15	standard deviation of the random perturbation field at each grid point	max_dom
stddev_cutoff_spp_pbl	2.0	cutoff tails of the pdf perturbation pattern above this threshold standard deviation	max_dom
vertstruc_spp_pbl	1	vertical structure type for random perturbation; =0 : constant =1 : random phase	single entry
iseed_spp_pbl	217	seed for the random number stream for spp_pbl	single entry

Note

The following subset of options are specific to the RUC LSM scheme - they work when spp=1 and sf_surface_physics=3.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
spp_lsm	1	Turns on perturbation of RUC LSM parameters	max_dom
lengthscale_spp_lsm	50000	perturbation length scale (in meters)	max_dom
timescale_spp_lsm	86400	temporal decorrelation of the random field (in seconds)	max_dom
gridpt_stddev_spp_lsm	0.3	standard deviation of the random perturbation field at each grid point	max_dom
stddev_cutoff_spp_lsm	3.0	cutoff tails of the pdf perturbation pattern above this threshold standard deviation	max_dom
vertstruc_spp_lsm	1	vertical structure type for random perturbation; =0 : constant =1 : random phase	single entry
iseed_spp_lsm	317	seed for the random number stream for spp_lsm	single entry

WRF-Solar Stochastic Ensemble Prediction System (WRF-Solar EPS)

The following options are specific to the WRF-Solar Stochastic Ensemble Prediction System (WRF-Solar EPS) and work when multi_perturb=1 and with WRFv4.4+. These options are set in the &stoch namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
nens	1	seed for the random number stream; in ensemble forecasts this parameter must be different for each member; the seed is a function of the initial time to ensure different random number streams are created for forecasts starting from different times; changing this seed changes the random number streams for all activated stochastic parameterization schemes	single entry
multi_perturb	0	set to 1 to turn on stochastic perturbations tailored for solar energy applications	max_dom
spdt	-1.0	frequency (in minutes) at which stochastic perturbations are updated; a negative value results in updates every time_step	max_dom
num_pert_3d	15	Number of entries in STOCHPERT.TBL; no need to modify	single entry

Note

The following subset of options are specific to FARMS parameterization perturbations, and work when pert_farms=.true., multi_perturb=1, swint_opt=2, and with WRFv4.4+.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
pert_farms	.false.	set to .true. to turn on perturbations to FARMS parameterization	max_dom
pert_farms_albedo	0	set to 1 to perturb albedo	max_dom
pert_farms_aod	0	set to 1 to perturb aerosol optical depth (AOD)	max_dom
pert_farms_angexp	0	set to 1 to perturb aerosol Angstrom exponent (angexp)	max_dom
pert_farms_aerasy	0	set to 1 to perturb aerosol asymmetry factor (aerasy)	max_dom
pert_farms_qv	0	set to 1 to perturb water vapor mixing ratio (qv)	max_dom
pert_farms_qc	0	set to 1 to perturb cloud water mixing ratio (qc)	max_dom
pert_farms_qs	0	set to 1 to perturb snow mixing ratio (qs)	max_dom

Note

The following subset of options are specific to Deng’s shallow cumulus parameterization perturbations, and work when pert_deng=.true., multi_perturb=1, shcu_physics=5, and with WRFv4.4+.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
pert_deng	.false.	set to .true. to activate perturbations to Deng’s shallow cumulus parameterization scheme	max_dom
pert_deng_qv	0	set to 1 to perturb water vapor mixing ratio (qv)	max_dom
pert_deng_qc	0	set to 1 to perturb cloud water mixing ratio (qc)	max_dom
pert_deng_t	0	set to 1 to perturb temperature	max_dom
pert_deng_w	0	set to 1 to perturb vertical velocity (w)	max_dom

Note

The following subset of options are specific to MYNN PBL perturbations, and work when pert_mynn=.true., multi_perturb=1, bl_pbl_physicss=5 or 6, and with WRFv4.4+.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
pert_mynn	.false.	set to .true. to activate perturbations for MYNN PBL schemes	max_dom
pert_mynn_qv	0	set to 1 to perturb water vapor mixing ratio (qv)	max_dom
pert_mynn_qc	0	set to 1 to perturb cloud water mixing ratio (qc)	max_dom
pert_mynn_t	0	set to 1 to perturb temperature	max_dom
pert_mynn_qke	0	set to 1 to perturb vertical velocity (w)	max_dom

Note

The following subset of options are specific to Noah LSM perturbations, and work when pert_noah=.true., multi_perturb=1, sf_surface_physics=2, and with WRFv4.4+.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
pert_noah	.false.	set to .true. to activate perturbations to the Noah LSM scheme	max_dom
pert_noah_qv	0	set to 1 to perturb water vapor mixing ratio (qv)	max_dom
pert_noah_smois	0	set to 1 to perturb soil moisture (smois)	max_dom
pert_noah_t	0	set to 1 to perturb temperature	max_dom
pert_noah_tslb	0	set to 1 to perturb soil temperature (tslb)	max_dom

Note

The following subset of options are specific to Thompson microphysics perturbations, and work when pert_noah=.true., multi_perturb=1, mp_physics=8, and with WRFv4.4+.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
pert_thom	.false.	set to .true. to activate perturbations to Thompson microphysics	max_dom
pert_thom_qv	0	set to 1 to perturb water vapor mixing ratio (qv)	max_dom
pert_thom_qc	0	set to 1 to perturb cloud water mixing ratio (qc)	max_dom
pert_thom_qi	0	set to 1 to perturb ice mixing ratio (qi)	max_dom
pert_thom_qs	0	set to 1 to perturb snow mixing ratio (qs)	max_dom
pert_thom_ni	0	set to 1 to perturb ice number concentration (ni)	max_dom

Note

The following subset of options are specific to Sundqvist et al., 1989 optical depth cloud effect perturbations, and work when pert_noah=.true., multi_perturb=1, icloud=3, and with WRFv4.4+.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
pert_cld3	.false.	set to .true. to activate perturbations to clouds generated with icloud=3	max_dom
pert_cld3_qv	0	set to 1 to perturb water vapor mixing ratio (qv)	max_dom
pert_cld3_t	0	set to 1 to perturb temperature	max_dom

&dynamics

To use the options in this section, they must be set in the &dynamics namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
hybrid_opt	2	dynamical coordinate option; =0 : original WRF terrain-following coordinate (this option was default for WRFv3) =2 : Klemp cubic form for the critical eta level (etac) (default in WRFv4.0+))	single entry
etac	0.2	the critical eta level at which model layers become completely isobaric - when znw(k) < etac, eta surfaces become isobaric; 0.2 is a good default value; see WRF/doc/README.hybrid_vert_coord for details	single entry
rk_ord	3	time integration scheme used; =2 : Runge-Kutta 2nd order =3 : Runge-Kutta 3rd order; recommended setting	single entry
diff_opt	-1	turbulence and mixing option; =0 : no turbulence or explicit spatial numerical filters are used; km_opt is ignored =1 : evaluates the 2nd-order diffusion term on coordinate surfaces; uses kvdif for vertical diffusion unless the PBL option is used; may be used with km_opt=1, which is recommended for real-data cases, and km_opt=4 =2 : evaluates mixing terms in physical space (stress form; x,y,z); turbulence parameterization is chosen by specifying km_opt	max_dom
km_opt	-1	eddy coefficient option; =0 : turned off =1 : constant; use khdif and kvdif =2 : 1.5 order TKE closure (3D); not recommeded for DX > 2 km =3 : Smagorinsky first order closure (3D); not recommended for DX > 2 km =4 : horizontal Smagorinsky first-order closure; recommended for real-data cases =5 : Scale-aware 3DTKE LES/PBL scheme; works when diff_opt=2, bl_pbl_physics=0, and sf_sfclay_physics=1,5,91, and with WRFv4.2+	max_dom
diff_6th_opt	0	6th-order numerical diffusion option; =0 : no 6th-order diffusion =1 : 6th-order numerical diffusion =2 : 6th-order numerical diffusion, but prohibits up-gradient diffusion	max_dom
diff_6th_factor	0.12	6th-order numerical diffusion non-dimensional rate; max value 1.0 corresponds to complete removal of the 2*dx wave in one time_step	max_dom
diff_6th_slopeopt	0	set to 1 to turn on 6th-order numerical diffusion - terrain-slope tapering	max_dom
diff_6th_thresh	0.1	slope threshold (m/m) that, when reached, turns off 6th-order diffusion in steep terrain	max_dom
damp_opt	3	the type of upper-level damping to use; =0 : no damping =1 : diffusive damping; may be used for real-data cases; dampcoef nondimensional ~0.01-0.1 =2 : Rayleigh damping; dampcoef inverse time scale (1/s), for e.g., 0.003 =3 : Rayleigh damping; for real-data cases; dampcoef inverse time scale (1/s), for e.g., 0.2	single entry
use_theta_m	1	use moist theta [theta_m=theta(1+1.61Qv)]; set to 0 to turn off	single entry
use_q_diabatic	0	set to 1 to include water vapor mixing ratio (QV) and cloud water mixing ratio (QC) tendencies during advection; helps with solution accuracy in an idealized “moist benchmark” test case (Bryan, 2014); for real-data testing, reduce the time_step namelist option to maintain stability	single entry
dampcoef	0.2	damping coefficient; see damp_opt	max_dom
c_s	0.25	Smagorinsky coefficient	max_dom
c_k	0.15	TKE coefficient	max_dom
zdamp	5000	damping depth (in meters) from the model top	max_dom
w_damping	0	set to 1 to turn on vertical velocity damping; for operational use	single entry
w_crit_cfl	1	vertical courant number where vertical damping begins	single entry
zadvect_implicit	0	set to 1 to use the implicit/explicit vertical advection (IEVA) scheme, which allows for a larger time_step for grids with large aspect ratios (dx/dz >> 1) that permit explicit convection	single entry
base_pres	100000	the base state surface pressure (in Pa) works for real-data cases; it is not recommended to change the default value	single entry
base_temp	290	base state temperature (in K) works for real-data cases	single entry
base_lapse	50	lapse rate (in K); it is not recommended to change the default value works for real-data cases	single entry
iso_temp	200	isothermal temperature in the statosphere; enables the model to extend up to 5 mb works for real-data cases	single entry
base_pres_strat	0	base state pressure (in Pa) at the bottom of the stratosphere; US Standard atmosphere 55 hPa works for real-data cases	single entry
base_lapse_strat	-11	base state lapse rate (dT/d(lnP)) in the stratosphere; approximate to the -12K US standard atmosphere value works for real-data cases	single entry
use_baseparam_fr_nml	.false.	set to .true. to use base state parameters from the namelist; for backward compatibility to use with wrfinput files produced prior to WRFv3.4	single entry
use_input_w	.false.	set to .true. to use vertical velocity from the input file	single entry
khdif	0	horizontal diffusion constant (m 2/s)	max_dom
kvdif	0	vertical diffusion constant (m 2/s)	max_dom
smdiv	0.1	divergence damping; 0.1 is typical	max_dom
emdiv	0.01	external-mode filter coefficent for the mass coordinate model; 0.01 is typical for real-data cases	max_dom
epssm	0.1	time off-centering (slightly forward) for the vertical pressure gradient (or sound waves) in an effort to damp 3-d divergence; set \(\leq\) 0.5	max_dom
non-hydrostatic	.true.	instructs WRF to run in non-hydrostatic mode; set to .false. to run in hydrostatic mode	max_dom
pert_coriolis	.false.	when set to .true. coriolis only acts on wind perturbation works for idealized cases	max_dom
top_lid	.false.	set to .true. for zero vertical motion at the top of domain works for idealized cases	max_dom
mix_full_fields	.false.	recommended setting is .true. except for highly-idealized numerical tests; when set to .false. the 1D base-state profile is subtracted before mixing works when diff_opt=2 and when damp_opt \(\neq\) 1	max_dom
mix_isotropic	0	=0 : anistropic vertical/horizontal diffusion =1 : isotropic; works when km_opt=2 or 3	max_dom
mix_upper_bound	0.1	non-dimensional upper limit for diffusion coefficients works when km_opt=2 or 3	max_dom
h_mom_adv_order	5	horizontal momentum advection order; 5=5th, etc.	max_dom
v_mom_adv_order	3	vertical momentum advection order; 3=3rd, etc.	max_dom
h_sca_adv_order	5	horizontal scalar advection order; 5=5th, etc.	max_dom
v_sca_adv_order	3	vertical scalar advection order; 3=3rd, etc.	max_dom
time_step_sound	0	number of sound steps per timestep; if using a time_step much larger than 6xDX (in km), increase this setting	max_dom
moist_adv_opt	1	advection option for moisture; =0 : simple =1 : positive-definite =2 : monotonic =3 : 5th-order WENO (Weighted Essentially Non-Oscillatory) =4 : 5th-order WENO with positive definite	max_dom
scalar_adv_opt	1	advection option for scalars; =0 : simple =1 : positive-definite =2 : monotonic =3 : 5th-order WENO (Weighted Essentially Non-Oscillatory) =4 : 5th-order WENO with positive definite	max_dom
tke_adv_opt	1	advection option for TKE; =0 : simple =1 : positive-definite =2 : monotonic =3 : 5th-order WENO (Weighted Essentially Non-Oscillatory) =4 : 5th-order WENO with positive definite	max_dom
phi_adv_z	1	vertical advection option for geopotential; =1 : original =2 : avoid double staggering of omega	max_dom
chem_adv_opt	1	advection option for variables; =0 : simple =1 : positive-definite =2 : monotonic =3 : 5th-order WENO (Weighted Essentially Non-Oscillatory) =4 : 5th-order WENO with positive definite	max_dom
tracer_adv_opt	1	advection option for tracer variables; =0 : simple =1 : positive-definite =2 : monotonic =3 : 5th-order WENO (Weighted Essentially Non-Oscillatory) =4 : 5th-order WENO with positive definite	max_dom
momentum_adv_opt	1	advection option for momentum; =1 : standard =3 : 5th-order WENO (Weighted Essentially Non-Oscillatory)	max_dom
tke_drag_coefficient	0	surface drag coefficient (dimensionless) works when diff_opt=2	max_dom
tke_heat_flux	0	surface thermal flux \((H/rho \times cp)\); \((K m s^{-1})\) works when diff_opt=2	max_dom
fft_filter_lat	91	a latitude (degrees) where the polar filter starts; the filter is activated from this latitude, up/down to the nearest pole; 45 is a reasonable latitude to start using polar filters works when using a global domain	single entry
coupled_filtering	.true.	uses polar filters for MU coupled scalar arrays	single entry
pos_def	.false.	set to .true. to remove any negative scalar array values	single entry
swap_pole_with_next_j	.false.	set to .true. to replace the domain’s values at the pole, j=1 (jds-1), with the values from the next row, j=2 (jds-2)	single entry
actual_distance_average	.false.	set to .true. to average the field at each i location in the j-loop with a number of grid points based on a map-factor ratio	single entry
gwd_opt	0	option for sub-grid orographic gravity-wave vertical momentum transport (or drag); can be used for all grid sizes when appropriate geogrid input fields are included (details); =0 : off =1 : gravity wave drag and blocking =3 : gravity wave drag, blocking, small-scale gravity drag and turbulent orographic form drag	max_dom
do_avgflx_em	0	set to 1 to output time-averaged mass-coupled advective velocities	max_dom
do_avgflx_cugd	0	set to 1 to output time-averaged convective mass-fluxes calculated by the Grell-Devenyi ensemble scheme works when do_avgflx_em =1 and cu_physics=93	max_dom
sfs_opt	0	nonlinear backscatter and anisotrophy (NBA); =0 : off =1 : NBA, using diagnostic stress terms; works when km_opt=2 or 3 for scalars =2 : NBA, using TKE-based stress terms; works when km_opt=2 or 3	max_dom
m_opt	0	set to 1 to output Mij stress terms when NBA is not used (sfs_opt=0)	max_dom
tracer_opt	0	set to 2 to activate eight pre-defined tracers (found in the Registry file)	max_dom
rad_nudge	0	set to 1 to turn on nudging toward the initial sounding in the tropical cyclone idealized case works when WRF is compiled for the tropical cyclone idealized case	single entry

The following options are specific to deactivating 2nd and 6th order horizontal filters for specific scalar variable classes. These options are set in the &dynamics namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
moist_mix2_off	.false.	set to =.true. to deactivate 2nd-order horizontal mixing for moisture	max_dom
chem_mix2_off	.false.	set to =.true. to deactivate 2nd-order horizontal mixing for chem species	max_dom
tracer_mix2_off	.false.	set to =.true. to deactivate 2nd-order horizontal mixing for tracers	max_dom
scalar_mix2_off	.false.	set to =.true. to deactivate 2nd-order horizontal mixing for scalars	max_dom
tke_mix2_off	.false.	set to =.true. to deactivate 2nd-order horizontal mixing for TKE	max_dom
moist_mix6_off	.false.	set to =.true. to deactivate 6th-order horizontal mixing for moisture	max_dom
chem_mix6_off	.false.	set to =.true. to deactivate 6th-order horizontal mixing for chem species	max_dom
tracer_mix6_off	.false.	set to =.true. to deactivate 6th-order horizontal mixing for tracers	max_dom
scalar_mix6_off	.false.	set to =.true. to deactivate 6th-order horizontal mixing for scalars	max_dom
tke_mix6_off	.false.	set to =.true. to deactivate 6th-order horizontal mixing for TKE	max_dom

&bdy_control

To use the options in this section, they must be set in the &bdy_control namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
spec_bdy_width	5	total number of rows for specified boundary value nudging; only for real-data cases	single entry
spec_zone	1	number of points in specified zone when specified=.true.; only for real-data cases	single entry
relax_zone	4	number of points in relaxation zone when specified=.true.; only for real-data cases	single entry
specified	.false.	set to =.true. to use a specified boundary condition; can only be used for domain 1; only for real-data cases	max_dom
spec_exp	0	exponential multiplier for relaxation zone ramp when specified=.true.; 0 = linear ramp; 0.33 = ~3*DX exp decay factor; only for real-data cases	single entry
multi_bdy_files	.false.	set to =.true. to instruct real.exe to generate multiple wrfbdy files (one time period per file, using bdy_inname=wrfbdy_d01_<date>)	single entry
periodic_x	.false.	set to =.true. to use periodic boundary conditions in the x-direction	max_dom
symmetric_xs	.false.	set to =.true. to use symmetric boundary conditions on the x start side (west side)	max_dom
symmetric_xe	.false.	set to =.true. to use symmetric boundary conditions on the x end side (east side)	max_dom
open_xs	.false.	set to =.true. to use open boundary conditions on the x start side (west side)	max_dom
open_xe	.false.	set to =.true. to use open boundary conditions on the x end side (east side)	max_dom
periodic_y	.false.	set to =.true. to use periodic boundary conditions in the y-direction	max_dom
symmetric_ys	.false.	set to =.true. to use symmetric boundary conditions on the y start side (south side)	max_dom
symmetric_ye	.false.	set to =.true. to use symmetric boundary conditions on the y end side (north side)	max_dom
open_ys	.false.	set to =.true. to use open boundary conditions on the y start side (south side)	max_dom
open_ye	.false.	set to =.true. to use open boundary conditions on the y end side (north side)	max_dom
nested	.false.	set to =.true. to use nested boundary conditions; must be set to .true. for nests	max_dom
polar	.false.	set to =.true. to use a polar boundary condition (v=0 at polarward-most v-point); use for global application	max_dom
constant_bc	.false.	set to =.true. to use a constant boundary condition; for dfi_opt>0	single entry
have_bcs_moist	.false.	set to =.true. to use the microphysics variables from the wrfbdy file in wrf.exe after running ndown	max_dom
have_bcs_scalar	.false.	set to =.true. to use scalar variables from the wrfbdy file in wrf.exe after running ndown	max_dom

&fdda

The following options are specific to Grid Nudging and assume grid_fdda=1 for each domain.
To use the options in this section, they must be set in the &fdda namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
grid_fdda	0	option to turn on grid nudging; =0 : off =1 : grid analysis nudging on =2 : spectral analysis nudging on	max_dom
gfdda_inname	wrffdda_d<domain>	defined name of grid nudging input file that is produced when running real.exe	single entry
gfdda_interval_m	0	time interval (in mins) between analysis times	max_dom
gfdda_end_h	0	time (in hours) from the initial forecast time, to stop nudging	max_dom
io_form_gfdda	2	output format for grid analysis data; =2 : NetCDF =4 : PHD5 =5 : GRIB1 =10 : GRIB2 =11 : pNetCDF	single entry
fgdt	0	calculation frequency (in mins) for analysis nudging; 0=every time step, which is recommended	max_dom
if_no_pbl_nudging_uv	0	set to =1 to turn off nudging of u and v in the PBL	max_dom
if_no_pbl_nudging_t	0	set to =1 to turn off nudging of temperature in the PBL	max_dom
if_no_pbl_nudging_q	0	set to =1 to turn off nudging of qvapor in the PBL	max_dom
guv	0	nudging coefficient for u and v (s-1); a reasonable value is 0.0003	max_dom
gt	0	nudging coefficient for temperature (s-1); a reasonable value is 0.0003	max_dom
gq	0	nudging coefficient for qvapor (s-1); a reasonable value is 0.0003	max_dom
if_ramping	0	the method for ending nudging; =0 : nudging ends as a step function =1 : nudging ramps down at the end of the period	single entry
dtramp_min	0	timestep (in mins) for ramping function	single entry
grid_sfdda	0	type of surface grid nudging; =0 : none =1 : nudging for selected surface fields =2 : FASDAS (Flux-Adjusted Surface Data Assimilation System) nudging	max_dom
sgfdda_inname	wrfsfdda_d<domain>	defined name of surface nudging input file that comes from the OBSGRID program	single entry
sgfdda_interval_m	0	time interval (in mins) between surface analysis times	max_dom
sgfdda_end_h	0	time (in hours) from the initial forecast time, to stop surface nudging	max_dom
io_form_sgfdda	2	surface analysis output format; =2 : NetCDF	single entry
guv_sfc	0	surface nudging coefficient for u and v (s-1); a reasonable value is 0.0003	max_dom
gt_sfc	0	surface nudging coefficient for temperature (s-1); a reasonable value is 0.0003	max_dom
gq_sfc	0	surface nudging coefficient for qvapor (s-1); a reasonable value is 0.00001	max_dom
rinblw	0	radius of influence used to determine the confidence (or weights) for analysis, which is based on the distance between the grid point to the nearest observation; analysis for grid points without nearvy observations is used at a reduced weight	max_dom

Spectral Nudging

The following options are specific to Spectral Nudging and assume grid_fdda=2 for each domain. These options are set in the &fdda namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
fgdtzero	0	set to =1 to nudge tendencies to zero in between fdda calls	max_dom
if_no_pbl_nudging_ph	0	set to =1 to turn off nudging of perturbation geopotential (ph) in the PBL	max_dom
if_zfac_uv	0	determines which layers nudging will occur for u and v; =0 : nudge in all layers =1 : limit nudging to levels above k_zfac_uv	max_dom
k_zfac_uv	0	below this model level, nudging is turned off for u and v	max_dom
dk_zfac_uv	1	depth (in k dimension) between k_zfac_uv to dk_zfac_uv where nudging increases linearly to full strength	max_dom
if_zfac_t	0	determines which layers nudging will occur for temperature; =0 : nudge temperature in all layers =1 : limit nudging to levels above k_zfac_t	max_dom
k_zfac_t	0	below this model level, nudging is turned off for temperature	max_dom
dk_zfac_t	1	depth (in k dimension) between k_zfac_t to dk_zfac_t where nudging increases linearly to full strength	max_dom
if_zfac_ph	0	determines which layers nudging will occur for perturbation geopotential (ph); =0 : nudge ph in all layers =1 : limit nudging to levels above k_zfac_tph	max_dom
k_zfac_ph	0	below this model level, nudging is turned off for perturbation geopotential (ph)	max_dom
dk_zfac_ph	1	depth (in k dimension) between k_zfac_ph to dk_zfac_ph where nudging increases linearly to full strength	max_dom
if_zfac_q	0	determines which layers nudging will occur for qvapor; =0 : nudge qvapor in all layers =1 : limit nudging to levels above k_zfac_tq	max_dom
k_zfac_q	0	below this model level, nudging is turned off for qvapor	max_dom
dk_zfac_q	1	depth (in k dimension) between k_zfac_q to dk_zfac_q where nudging increases linearly to full strength	max_dom
gph	0	nudging coefficient for perturbation geopotential (ph); a reasonable value is 0.0003	max_dom
ktrop	0	option to cap spectral nudging of potential temperature and water vapor mixing ratio at a user-defined layer above the PBL; nominally selected to represent the tropopause	single entry
xwavenum	0	top wave number to nudge in the x-direction; a reasonable value is 3	max_dom
ywavenum	0	top wave number to nudge in the y-direction; a reasonable value is 3	max_dom

Observational Nudging

The following options are specific to Observational Nudging and assume obs_nudge_opt=1 for each domain. These options are set in the &fdda namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
obs_nudge_opt	0	set to =1 to turn on observational nudging; must also set auxinput11_invterval and auxinput11_end_h under &time_control in namelist.input	max_dom
max_obs	0	maximum number of observations used for a domain during any given time window	single entry
fdda_start	0	observational nudging start time (in mins)	max_dom
fdda_end	0	observational nudging end time (in mins)	max_dom
obs_nudge_wind	0	set to =1 to turn on wind nudging	max_dom
obs_coef_wind	0	nudging coefficient for wind (s-1)	max_dom
obs_nudge_temp	0	set to =1 to turn on temperature nudging	max_dom
obs_coef_temp	0	nudging coefficient for temperature (s-1)	max_dom
obs_nudge_mois	0	set to =1 to turn on vapor mixing ratio nudging	max_dom
obs_coef_mois	0	nudging coefficient for vapor mixing ratio (s-1)	max_dom
obs_rinxy	0	horizontal radius of influence (in km)	max_dom
obs_rinsig	0	vertical radius of influence (in eta)	single entry
obs_twindo	0	half-period time window over which an observation is used for nudging (in hours)	max_dom
obs_npfi	0	frequency in coarse grid timesteps for diagnostic prints	single entry
obs_ionf	1	frequency in coarse grid timesteps for observational input and error calculation	max_dom
obs_idynin	0	for dynamic initialization, turns on ramping-down function to gradually turn off FDDA before the pure forecast	single entry
obs_dtramp	0	time period (in mins) over which the nudging is ramped down from one to zero	single entry
obs_prt_max	1000	maximum allowed obs entries in diagnostic printout	single entry
obs_prt_freq	1000	frequency in observation index for diagnostic printout	max_dom
obs_ipf_in4dob	.false.	set to =.true. to print observational input diagnostics	single entry
obs_ipf_errob	.false.	set to =.true. to print observational error diagnostics	single entry
obs_ipf_nudob	.false.	set to =.true. to print observational nudging diagnostics	single entry
obs_ipf_init	.true.	enables observational printed warning messages	single entry
obs_no_pbl_nudge_uv	0	set to =1 to turn off wind nudging within the PBL	max_dom
obs_no_pbl_nudge_t	0	set to =1 to turn off temperature nudging within the PBL	max_dom
obs_no_pbl_nudge_q	0	set to =1 to turn off moisture nudging within the PBL	max_dom
obs_nudgezfullr1_uv obs_nudgezfullr1_t obs_nudgezfullr1_q	50	vertical influence of full weight height for lowest model level observations, PBL regime 1, winds (uv), temperature (t), and moisture (q)	single entry
obs_nudgezrampr1_uv obs_nudgezrampr1_t obs_nudgezrampr1_q	50	vertical influence of ramp-to-zero height for lowest model level observations, regime 1, winds (uv), temperature (t), and moisture (q)	single entry
obs_nudgezfullr2_uv obs_nudgezfullr2_t obs_nudgezfullr2_q	50	Vertical influence of full weight height for lowest model level observations, regime 2, winds (uv), temperature (t), and moisture (q)	single entry
obs_nudgezrampr2_uv obs_nudgezrampr2_t obs_nudgezrampr2_q	50	vertical influence of ramp-to-zero height for lowest model level observations, regime 2, winds (uv), temperature (t), and moisture (q)	single entry
obs_nudgezfullr4_uv obs_nudgezfullr4_t obs_nudgezfullr4_q	-5000	Vertical influence of full weight height for lowest model level observations, regime 4, winds (uv), temperature (t), and moisture (q)	single entry
obs_nudgezrampr4_uv obs_nudgezrampr4_t obs_nudgezrampr4_q	50	vertical influence of ramp-to-zero height for lowest model level observations, regime 4, winds (uv), temperature (t), and moisture (q)	single entry
obs_nudgezfullmin	50	minimum depth (in meters) through which the vertical influence function remains 1.0	single entry
obs_nudgezrampmin	50	minimum depth (in meters) through which the vertical influence function decreases from 1 to 0	single entry
obs_nudgezmax	3000	max depth (in meters) in which vertical influence function is non-zero	single entry
obs_sfcfact	1.0	scale factor applied to the time window for surface observations	single entry
obs_sfcfacr	1.0	scale factor applied to horizontal radius of influence for surface observations	single entry
obs_dpsmx	7.5	max pressure change ( in cb) allowed within the horizontal radius of influence	single entry
obs_sfc_scheme_horiz	0	horizontal spreading scheme for surface observations; =0 : WRF scheme =1 : MM5 scheme	single entry
obs_sfc_scheme_vert	0	vertical spreading scheme for surface observations; =0 : regime vif scheme =1 : original (simple) scheme	single entry
obs_max_sndng_gap	20	max allowed pressure gap (in cb) between soundings for interpolation	single entry
obs_scl_neg_qv_innov	0	set to =1 to prevent nudging toward negative Qv	single entry

&noah_mp

To use the options in this section, they must be set in the &noah_mp namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
dveg	4	dynamic vegetation option; for all options; LAI = leaf area index FVEG = vegetation fraction SHDFAC = model variable for veg fraction =1 : off; LAI from table; FVEG = SHDFAC =2 : on; LAI predicted; FVEG calculated =3 : off; LAI from table; FVEG calculated =4off; LAI from table; FVEG = max veg fraction =5 : on; LAI predicted; FVEG = max veg fraction =6 : on; use FVEG - SHDFAC from input =7 : off; use input LAI; use FVEG - SHDFAC from input =8 : off; use input LAI; calculate FVEG =9 : off; use input LAI; use max veg fraction =10 : crop model on; use max veg fraction	single entry
opt_crs	1	stomatal resistance option; =1 : Ball-Berry =2 : Jarvis	single entry
opt_sfc	1	surface layer drag coefficient calculation; =1 : Monin-Obukhov =2 : original Noah (Chen97)	single entry
opt_btr	1	soil moisture factor for stomatal resistance; =1 : Noah =2 : CLM =3 : SSiB	single entry
opt_run	3	runoff and groundwater option; =1 : TOPMODEL with groundwater =2 : TOPMODEL with equilibrium water table =3 : original surface and subsurface runoff (free drainage) =4 : BATS (Biosphere-Atmosphere Transfer Scheme) surface and subsurface runoff (free drainage) =5 : Miguez-Macho & Fan groundwater scheme (Miguez-Macho et al., 2007, Fan et al., 2007); geogrid must be run with GEOGRID.TBL.ARW.noahmp; use with caution! =6 : Variable Infiltration Capacity Model Surface Runoff scheme (Wood et al., 1992); works in V4.4+ =7 : Xiananjiang Infiltration and Surface Runoff scheme (Jayawardena and Zhou, 2000); works in V4.4+ =8 : Dynamic VIC Surface Runoff scheme (Liang and Xie, 2001); works in V4.4+	single entry
opt_infdv	0	infiltration option in dynamic VIC runoff scheme; only works when opt_run=8; works in V4.4+; =0 : off =1 : Philip scheme =2 : Green-Ampt scheme =3 : Smith-Parlange scheme	single entry
opt_frz	1	supercooled liquid water option; =1 : no iteration =2 : Koren’s iteration	single entry
opt_inf	1	soil permeability option; =1 : linear effect, more permeable =2 : non-linear effect; less permeable	single entry
opt_rad	3	radiative transfer option; =1 : modified two-stream; known to cause problems when vegetation fraction is small =2 : two-stream applied to grid cell =3 : two-stream applied to veg fraction	single entry
opt_alb	2	ground surface albedo option; =1 : BATS =2 : CLASS (Canadian Land Surface Scheme)	single entry
opt_snf	1	precipitation partitioning between snow and rain; =1 : Jordan, 1991 =2 : BATS; snow when SFCTMP<TFRZ+2.2 =3 : snow when SFCTMP<TFRZ =4 : use WRF precipitation partitioning =5 : use wetbulb temperature (Wang et al., 2019)	single entry
opt_tbot	2	soil temperature lower boundary condition; =1 : zero heat flux =2 : TBOT at 8 m from input file	single entry
opt_stc	1	snow/soil temperature time scheme; =1 : semi-implicit =2 : fully-implicit =3 : semi-implicit; where temperatures use snow cover fraction	single entry
opt_gla	1	glacier treatment option; =1 : includes phase change =2 : slab ice (Noah)	single entry
opt_rsf	1	surface evaporation resistence option; =1 : Sakaguchi and Zeng, 2009 =2 : Sellers, 1992 =3 : adjusted Sellers to decrease RSURF for wet soil =4 : option 1 for non-snow; rsurf=rsurf_snow for snow; set in MPTABLE	single entry
opt_soil	1	options for defining soil properties; geogrid must have been run with GEOGRID.TBL.ARW.noahmp; use with caution; =1 : use input dominant soil texture =2 : use input soil texture that varies with depth =3 : use soil composition (sand, clay, orgm) and pedotransfer functions (opt_pedo) =4 : use input foil properties (BEXP_3D, SMCMAX_3D, etc.); not valid in WRF	single entry
opt_pedo	1	option for pedotransfer functions; only works when opt_soil=3; geogrid must have been run with GEOGRID.TBL.ARW.noahmp; use with caution; =1 : Saxton and Rawls, 2006	single entry
opt_crop	0	options for crop model; =0 : no crop model; run default dynamic vegetation =1 : Liu et al., 2016 =2 : Gecros (Genotype-by-Environment interaction on CROp grown simulator; Yin and van Laar, 2005)	single entry
opt_irr	0	irrigation option; geogrid must have been run with GEOGRID.TBL.ARW.noahmp; use with caution; =0 : no irrigation =1 : irrigation on =2 : irrigation trigger based on crop season planting and harvesting dates =3 : irrigation trigger based on LAI (leaf area index) threshold	single entry
opt_irrm	0	options for irrigation method; only works when opt_irr>0; geogrid must have been run with GEOGRID.TBL.ARW.noahmp; use with caution; =0 : method based on geo_em fractions (all three methods are on) =1 : sprinkler method =2 : micro/drip irrigation =3 : surface flooding	single entry
opt_tdrn	0	tile drainage option; only confirmed to work with opt_run=3; geogrid must have been run with GEOGRID.TBL.ARW.noahmp; use with caution; new since V4.4; =0 : no tile drainage =1 : simple drainage =2 : Hooghoudt’s equation-based tile drainage	single entry
soiltstep	0.0	soil process timestep (in seconds) for solving soil water and temperature; new since V4.4; =0 : same as main NoahMP model timestep; = N*dt_noahmp : typically 15 or 30 mins	single entry
noahmp_output	1	Noah-MP output levels; new since V4.4; =1 : standard output =3 : standard output with additional water and energy budget term	single entry
noahmp_acc_dt	0.0	bucket reset time interval (mins) between outputs for accumulation; only works with noahmp_output=3	single entry

&dfi_control

The following options are specific to Digital Filter Initialization (DFI) and assume dfi_opt>0.
To use the options in this section, they must be set in the &dfi_control namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
dfi_opt	0	digital filter initialization option; supports nesting with no feedback; =0 : no DFI =1 : digital filter launch (DFL) =2 : diabatic DFI (DDFI) =3 : twice DFI (TDFI); recommended	single entry
dfi_nfilter	7	type of digital filter to use when dfi_opt>0; =0 : uniform =1 : Lanczos =2 : Hamming =3 : Blackman =4 : Kaiser =5 : Potter =6 : Dolph window =7 : Dolph; recommended =8 : recursive high-order	single entry
dfi_write_filtered_input	.true.	when set to =.true., writes a wrfinput file with a filtered model state before beginning a forecast	single entry
dfi_write_dfi_history	.false.	set to =.true. to write wrfout files during filtering integration	single entry
dfi_cutoff_seconds	3600	cutoff period (in seconds) for the filter; should not be longer than the filter window	single entry
dfi_time_dim	1000	maximum number of time steps for the filtering period; this value can be larger than necessary	single entry

The following settings show an example for 1 hour backward integration for a model simulation that starts at 2004-03-13_12:00:00. These options are set in the &dfi_control namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
dfi_bckstop_year	2004	4-digit year of stop time for backward DFI integration	single entry
dfi_bckstop_month	3	2-digit month of stop time for backward DFI integration	single entry
dfi_bckstop_day	13	2-digit day of stop time for backward DFI integration	single entry
dfi_bckstop_hour	11	2-digit hour of stop time for backward DFI integration	single entry
dfi_bckstop_minute	0	2-digit minute of stop time for backward DFI integration	single entry
dfi_bckstop_second	0	2-digit second of stop time for backward DFI integration	single entry

The following settings specify 30 minutes of forward integration for a model simulation that starts at 2004-03-13_12:00:00. These options are set in the &dfi_control namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
dfi_fwdstop_year	2004	4-digit year of stop time for forward DFI integration	single entry
dfi_fwdstop_month	3	2-digit month of stop time for forward DFI integration	single entry
dfi_fwdstop_day	13	2-digit day of stop time for forward DFI integration	single entry
dfi_fwdstop_hour	12	2-digit hour of stop time for forward DFI integration	single entry
dfi_fwdstop_minute	30	2-digit minute of stop time for forward DFI integration	single entry
dfi_fwdstop_second	0	2-digit second of stop time for forward DFI integration	single entry
dfi_savehydmeteors	0	Option for radar data assimilation: =0 : sets hydrometeors to 0 and lets them spin up in DFI =1 : keeps hydrometeors unchanged	single entry

&grib2

To use the options in this section, they must be set in the &grib2 namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
background_proc_id	255	background generating process identifier (typically defined by the originating data center) to identify background data used in creating the data; this is octet 13 of Section 4 in the grib2 message	single entry
forecast_proc_id	255	analysis or generating forecast process identifier (typically defined by the originating data center) to identify the forecast process used to generate the data; this is octet 14 of Section 4 in the grib2 message	single entry
production_status	255	production status of processed data in the grib2 message; see Code Table 1.3 of the grib2 manual; this is octect 20 of Section 1 in the grib2 record	single entry
compression	40	the compression method to encode the output grib2 message; only supported types are: =40 : jpeg2000 =41 : PNG	single entry

&scm

The Single Column Model (SCM) can only be run for a single domain. All options require only a single entry in the namelist. To use the options in this section, they must be set in the &scm namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
scm_force	0	set to =1 to turn on single column forcing
scm_force_dx	4000	DX for SCM forcing (in meters)
num_force_layers	8	number of SCM input forcing layers
scm_lu_index	2	SCM landuse category; 2= dryland, cropland, and pasture; others can be found in the LANDUSE.TBL file in the run/ or test/em_real/ directory
scm_isltyp	4	SCM soil category; 4= silt loam; others can be found in the SOILPARM.TBL file in the run/ or test/em_real/ directory
scm_vegfra	50	SCM vegetation fraction (%)
scm_canwat	0	SCM canopy water (kg m-2)
scm_lat	36.605	SCM latitude
scm_lon	-97.485	SCM longitude
scm_th_adv	.true.	turns on theta advection in SCM
scm_wind_adv	.true.	turns on wind advection in SCM
scm_qv_adv	.true.	turns on moisture advection in SCM
scm_vert_adv	.true.	turns on vertical advection in SCM
scm_ql_adv	.false.	set to =.true. to turn on liquid advection in SCM
scm_force_skintemp	0	set to =1 to turn on SCM forcing by skin temp
scm_force_flux	0	set to =1 to turn on SCM forcing by surface fluxes
num_force_soil_layers	5	number of SCM soil forcing layers
scm_soilt_force	.false.	set to =.true. to turn on soil temperature forcing in SCM
scm_soilq_force	.false.	set to =.true. to turn on moisture forcing in SCM
scm_force_th_largescale	.false.	set to =.true. to turn on large-scale theta forcing in SCM
scm_force_qv_largescale	.false.	set to =.true. to turn on large-scale qv forcing in SCM
scm_force_ql_largescale	.false.	set to =.true. to turn on large-scale ql forcing in SCM
scm_force_wind_largescale	.false.	set to =.true. to turn on large-scale wind forcing in SCM

&tc

To use the options in this section, they must be set in the &tc namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
insert_bogus_storm	.false.	set to =.true. to insert a bogus tropical cyclone	single entry
remove_storm	.false.	set to =.true. to remove the original tropical cyclone; does not work if a TC did not already exist	single entry
num_storm	1	the number of bogus TCs in the domain	single entry
latc_loc	-999	center latitude of the bogus TC	max_bogus
lonc_loc	-999	center longitude of the bogus TC	max_bogus
vmax_meters_per_second	-999	wind max of bogus storm (m s-1)	max_bogus
rmax	-999	maximum radius outward from storm center of bogus TC	max_bogus
vmax_ratio	-999	ratio for representative maximum winds; 0.75 for 45 km grid, and 0.9 for 15 km grid	max_bogus
rankine_lid	-999	top pressure limit for the TC bogus scheme	single entry

&diags

To output fields on pressure levels (p_lev_diags=1)
The following variables must be set in the &time_control record:

• auxhist23_outname='wrfpress_d<domain>_<date>' : modify output stream and file name accordingly

• io_form_auxhist23=2 : 2=netCDF file format

• auxhist23_interval=180,180 : interval in minutes for each domain

• frames_per_auxhist23=1,1 : number of files output per interval period

To vertically interpolate diagnostics to z-levels (z_lev_diags=1)
The following additional variables must set in the &time_control record (note the use of stream 22, instead of 23, as is used above):

• auxhist22_outname='wrfpress_d<domain>_<date>' : modify output stream and file name accordingly

• io_form_auxhist22=2 : 2=netCDF file format

• auxhist22_interval=180,180 : interval in minutes for each domain

• frames_per_auxhist22=1,1 : number of files output per interval period

To use the options in this section, they must be set in the &diags namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
p_lev_diags	0	set to =1 to output pressure level diagnostics	single entry
num_press_levels	0	number of pressure levels	single entry
press_levels	0	specifically state the desired pressure levels (in Pa); one per num_press_levels	max_plevs
use_tot_or_hyd_p	2	pressure option; 1 : use total pressure 2 : use hydrostatic pressure	single entry
p_lev_missing	-999	missing value below ground	single entry
z_lev_diags	0	set to =1 to vertically interpolate diagnostics to z-levels	single entry
num_z_levels	0	number of height levels to interpolate to	single entry
z_levels	0	list of height values (in meters) to interpolate data to; positive numbers are for heights above mean sea level (i.e., a flight level); negative numbers are for levels above ground	max_zlevs
z_lev_missing	-999	missing value below ground	single entry
extrap_below_grnd	1	method used for extrapolating below ground; =1 : no extrapolation =2 : extrapolate adiabatically	single entry
solar_diagnostics	0	set to =1 to turn on solar forecasting diagnostics for additional solar-related outputs; see full description in the “output diagnostics” section of the WRF Output chapter; new since V4.2	single entry

&afwa

The following options are specific to AFWA diagnostics, and assumes afwa_daig_opt=1. To use the options in this section, they must be set in the &afwa namelist record.

Note

These options cannot be used with an OpenMP configuration.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
afwa_diag_opt	0	set to =1 to turn on AFWA diagnostics	max_dom
afwa_ptype_opt	0	set to =1 to turn on precipitation type option	max_dom
afwa_vil_opt	0	set to =1 to turn on vertical int liquid option	max_dom
afwa_radar_opt	0	set to =1 to turn on radar option	max_dom
afwa_severe_opt	0	set to =1 to turn on severe weather option	max_dom
afwa_icing_opt	0	set to =1 to turn on icing option	max_dom
afwa_vis_opt	0	set to =1 to turn on visibility option	max_dom
afwa_cloud_opt	0	set to =1 to turn on cloud option	max_dom
afwa_therm_opt	0	set to =1 to turn on thermal indices option	max_dom
afwa_turb_opt	0	set to =1 to turn on turbulence option	max_dom
afwa_buoy_opt	0	set to =1 to turn on buoyancy option	max_dom
afwa_ptype_ccn_tmp	264.15	CCN temperature for precipitation type calculation	single entry
afwa_ptype_tot_melt	50	total melting energy for precipitation type calculation	single entry

&ideal

To use the options in this section, they must be set in the &ideal namelist record.

Namelist Parameter	Default Setting	Description	Set for 1 or Multiple Domains (max_dom)
ideal_case	0	set to =1 to indicate this is an idealized test case; mandatory for all idealized cases	single entry