For more info on the fdda options, see this
36/12-km namelist and 4-km namelist

36/12-km Domain

 &time_control
 run_days                            = 0,
 run_hours                           = 0,
 run_minutes                         = 0,
 run_seconds                         = 0,
 start_year                          = 2008, 2008, 2008,
 start_month                         = 08,   08,   08,
 start_day                           = 29,   29,   29,
 start_hour                          = 12,   12,   12,
 start_minute                        = 00,   00,   00,
 start_second                        = 00,   00,   00,
 end_year                            = 2008, 2008, 2008,
 end_month                           = 09,   09,   09,
 end_day                             = 01,   01,   01,
 end_hour                            = 12,   12,   12,
 end_minute                          = 00,   00,   00,
 end_second                          = 00,   00,   00,
 interval_seconds                    = 10800
 input_from_file                     = .true.,.true.,.true.,
 history_interval                    = 60,  60,   60,
 frames_per_outfile                  = 1, 1, 1,
 restart                             = .false.,
 restart_interval                    = 1440,
 io_form_history                     = 2
 io_form_restart                     = 2
 io_form_input                       = 2
 io_form_boundary                    = 2
 debug_level                         = 0
 /

 &domains
 time_step                           = 216,
 time_step_fract_num                 = 0,
 time_step_fract_den                 = 1,
 max_dom                             = 2,
 s_we                                = 1,     1,     1,
 e_we                                = 151,   169,   346
 s_sn                                = 1,     1,     1,
 e_sn                                = 127,   142,   265
 s_vert                              = 1,     1,     1,
 e_vert                              = 38,    38,    38,	
 eta_levels                          = 1.000, 0.995, 0.990, 0.985, 0.980, 
	0.970, 0.960, 0.950, 0.940, 0.930, 
	0.920, 0.910, 0.900, 0.880, 0.860, 
	0.830, 0.800, 0.770, 0.740, 0.710, 
	0.680, 0.640, 0.600, 0.560, 0.520, 
	0.480, 0.440, 0.400, 0.360, 0.320, 
	0.280, 0.240, 0.200, 0.160, 0.120, 
	0.080, 0.040, 0.000
 num_metgrid_levels                  = 27
 dx                                  = 36000, 12000, 4000
 dy                                  = 36000, 12000, 4000
 grid_id                             = 1, 2, 3
 parent_id                           = 0, 1, 2
 i_parent_start                      = 1, 80, 40
 j_parent_start                      = 1, 36, 28
 parent_grid_ratio                   = 1, 3, 3
 parent_time_step_ratio              = 1, 3, 3
 feedback                            = 0,
 smooth_option                       = 0
 p_top_requested                     = 10000
 tile_sz_x                           = 0,
 tile_sz_y                           = 0,
 numtiles                            = 1,
 nproc_x                             = -1,
 nproc_y                             = -1,
 /

 &physics
 mp_physics                          = 8,     8,     8,  
 ra_lw_physics                       = 3,     3,     3,
 ra_sw_physics                       = 3,     3,     3,
 cam_abs_freq_s                      = 21600
 levsiz                              = 59
 paerlev                             = 29
 cam_abs_dim1                        = 4
 cam_abs_dim2                        = 38
 radt                                = 30,    30,    30,
 sf_sfclay_physics                   = 1,     1,     1,
 sf_surface_physics                  = 2,     2,     2,
 bl_pbl_physics                      = 1,     1,     1,
 bldt                                = 0,     0,     0,
 cu_physics                          = 1,     1,     1,
 cudt                                = 5,     5,     5,
 isfflx                              = 1,
 ifsnow                              = 1,
 icloud                              = 1,
 surface_input_source                = 1,
 num_soil_layers                     = 4,
 ucmcall                             = 1,
 mp_zero_out                         = 0,
 maxiens                             = 1,
 maxens                              = 3,
 maxens2                             = 3,
 maxens3                             = 16,
 ensdim                              = 144,
 /

 &fdda
 grid_fdda                           = 1, 0, 0
 gfdda_inname                        = 'wrffdda_d'
 gfdda_interval_m                    = 180, 0, 0,
 gfdda_end_h                         = 180, 0, 0,
 io_form_gfdda                       = 2
 fgdt                                = 0, 0, 0,
 if_no_pbl_nudging_uv                = 0, 0, 0,
 if_no_pbl_nudging_t                 = 1, 1, 1,
 if_no_pbl_nudging_q                 = 1, 1, 1
 if_zfac_uv                          = 0, 0, 0,
  k_zfac_uv                          = 10, 10, 10
 if_zfac_t                           = 1, 0, 0,
  k_zfac_t                           = 10, 10, 10
 if_zfac_q                           = 1, 0, 0,
  k_zfac_q                           = 10, 10, 10,
 guv                                 = 0.0001, 0.0001, 0.0001,
 gt                                  = 0.0001, 0.0001, 0.0001,
 gq                                  = 0.000001, 0.000001, 0.000001,
 if_ramping                          = 0
 dtramp_min                          = 0.0
 /

 &dynamics
 w_damping                           = 1,
 diff_opt                            = 1,
 km_opt                              = 4,
 diff_6th_opt                        = 0,
 diff_6th_factor                     = 0.12,
 base_temp                           = 290.
 damp_opt                            = 0,
 zdamp                               = 5000.,  5000.,  5000.,
 dampcoef                            = 0.01,   0.01,   0.01
 khdif                               = 0,      0,      0,
 kvdif                               = 0,      0,      0,
 non_hydrostatic                     = .true., .true., .true.,
 pd_moist                            = .true., .true., .true.,
 pd_scalar                           = .true., .true., .true.,
 /

 &bdy_control
 spec_bdy_width                      = 5,
 spec_zone                           = 1,
 relax_zone                          = 4,
 specified                           = .true., .false.,.false.,
 nested                              = .false., .true., .true.,
 /

 &grib2
 /

 &namelist_quilt
 nio_tasks_per_group = 0,
 nio_groups = 1,
 /

36/12-km namelist and 4-km namelist

4-km Domain

 &time_control
 run_days                            = 0,
 run_hours                           = 0,
 run_minutes                         = 0,
 run_seconds                         = 0,
 start_year                          = 2008, 2008, 2008,
 start_month                         = 05,   05,   05,
 start_day                           = 19,   19,   19,
 start_hour                          = 12,   12,   12,
 start_minute                        = 00,   00,   00,
 start_second                        = 00,   00,   00,
 end_year                            = 2008, 2008, 2008,
 end_month                           = 05,   05,   05,
 end_day                             = 22,   22,   22,
 end_hour                            = 12,   12,   12,
 end_minute                          = 00,   00,   00,
 end_second                          = 00,   00,   00,
 interval_seconds                    = 3600
 input_from_file                     = .true.,.true.,.true.,
 history_interval                    = 60,  60,   60,
 frames_per_outfile                  = 1, 1, 1,
 restart                             = .false.,
 restart_interval                    = 1440,
 io_form_history                     = 2
 io_form_restart                     = 2
 io_form_input                       = 2
 io_form_boundary                    = 2
 debug_level                         = 0
 /

 &domains
 time_step                           = 24,
 time_step_fract_num                 = 0,
 time_step_fract_den                 = 1,
 max_dom                             = 1,
 s_we                                = 1,     1,     1,
 e_we                                = 346,   ,   
 s_sn                                = 1,     1,     1,
 e_sn                                = 265,   ,   
 s_vert                              = 1,     1,     1,
 e_vert                              = 38,    38,    38,	
 eta_levels                          = 1.000, 0.995, 0.990, 0.985, 0.980, 
	0.970, 0.960, 0.950, 0.940, 0.930, 
	0.920, 0.910, 0.900, 0.880, 0.860, 
	0.830, 0.800, 0.770, 0.740, 0.710, 
	0.680, 0.640, 0.600, 0.560, 0.520, 
	0.480, 0.440, 0.400, 0.360, 0.320, 
	0.280, 0.240, 0.200, 0.160, 0.120, 
	0.080, 0.040, 0.000
 num_metgrid_levels                  = 27
 dx                                  = 4000, , 
 dy                                  = 4000, , 
 grid_id                             = 3, , 
 parent_id                           = 2, , 
 i_parent_start                      = 40, , 
 j_parent_start                      = 28, , 
 parent_grid_ratio                   = 3, , 
 parent_time_step_ratio              = 3, , 
 feedback                            = 0,
 smooth_option                       = 0
 p_top_requested                     = 10000
 /

 &physics
 mp_physics                          = 8,     8,     8,  
 ra_lw_physics                       = 3,     3,     3,
 ra_sw_physics                       = 3,     3,     3,
 cam_abs_freq_s                      = 21600
 levsiz                              = 59
 paerlev                             = 29
 cam_abs_dim1                        = 4
 cam_abs_dim2                        = 38
 radt                                = 30,    30,    30,
 sf_sfclay_physics                   = 1,     1,     1,
 sf_surface_physics                  = 2,     2,     2,
 bl_pbl_physics                      = 1,     1,     1,
 bldt                                = 0,     0,     0,
 cu_physics                          = 1,     1,     1,
 cudt                                = 5,     5,     5,
 isfflx                              = 1,
 ifsnow                              = 1,
 icloud                              = 1,
 surface_input_source                = 1,
 num_soil_layers                     = 4,
 ucmcall                             = 1,
 mp_zero_out                         = 0,
 maxiens                             = 1,
 maxens                              = 3,
 maxens2                             = 3,
 maxens3                             = 16,
 ensdim                              = 144,
 /

 &fdda
 grid_fdda                           = 0, , 
 gfdda_inname                        = 'wrffdda_d'
 gfdda_interval_m                    = 180, 0, 0,
 gfdda_end_h                         = 180, 0, 0,
 io_form_gfdda                       = 2
 fgdt                                = 0, 0, 0,
 if_no_pbl_nudging_uv                = 0, 0, 0,
 if_no_pbl_nudging_t                 = 1, 1, 1,
 if_no_pbl_nudging_q                 = 1, 1, 1
 if_zfac_uv                          = 0, 0, 0,
  k_zfac_uv                          = 10, 10, 10
 if_zfac_t                           = 1, 0, 0,
  k_zfac_t                           = 10, 10, 10
 if_zfac_q                           = 1, 0, 0,
  k_zfac_q                           = 10, 10, 10,
 guv                                 = 0.0001, 0.0001, 0.0001,
 gt                                  = 0.0001, 0.0001, 0.0001,
 gq                                  = 0.000001, 0.000001, 0.000001,
 if_ramping                          = 0
 dtramp_min                          = 0.0
 /

 &dynamics
 w_damping                           = 1,
 diff_opt                            = 1,
 km_opt                              = 4,
 diff_6th_opt                        = 0,
 diff_6th_factor                     = 0.12,
 base_temp                           = 290.
 damp_opt                            = 0,
 zdamp                               = 5000.,  5000.,  5000.,
 dampcoef                            = 0.01,   0.01,   0.01
 khdif                               = 0,      0,      0,
 kvdif                               = 0,      0,      0,
 non_hydrostatic                     = .true., .true., .true.,
 pd_moist                            = .true., .true., .true.,
 pd_scalar                           = .true., .true., .true.,
 /

 &bdy_control
 spec_bdy_width                      = 5,
 spec_zone                           = 1,
 relax_zone                          = 4,
 specified                           = .true., .false.,.false.,
 nested                              = .false., .true., .true.,
 /

 &grib2
 /

 &namelist_quilt
 nio_tasks_per_group = 0,
 nio_groups = 1,
 /