[Wrf-users] different problems with nesting in WRF-NMM

[Eduardo Penabad Ramos]

Dear users,
 
In my institution, we are testing NMM core of WRF in order to use it in some
of our operational tasks. In this early stage of implementation in our
computing environment we are facing with some troubles. Here they come a
couple of them:
 
 (1) Static fields resolution at nested grids:
     WRF static fields in nested grid outputs (i.e. LU_INDEX, LANDMASK, etc
in wrfout_d02 file) look like they have the coarser (d01) resolution. I
mean, this fields have values with d02 resolution, but this values are
diamond-shaped seeming to be just a downscaling of d01 fields. The question
is.... does WRF model use those fields written in the wrfout file or does it
use those written in the geo_nmm.nest.l01.nc file? if this were the case,
why WRF model doesn't dump the high-resolution fields in wrfout file?
 
 (2) Nested domain too close to the boundary of parent (WRF says):
    We are running  (let's say, trying to run) a 3 nests configuration (d01
@ 36km, d02 @ 12 km and d03 @ 4 km) with the namelist.input domains data
attached below. With i,j_parent_start values for d03 (56,76) and d02 e_we
and e_sn values  (121,196) one should expect that a d03 grid with e_we=82
and e_sn=182 will run, but I'm getting this error. Am I doing something
wrong? 
 
 -------------- FATAL CALLED ---------------
 FATAL CALLED FROM FILE:  NMM_NEST_UTILS1.b  LINE:     779
 1H:NESTED DOMAIN TOO CLOSE TO THE BOUNDARY OF PARENT
 -------------------------------------------
 
namelist.input details:
 
 &domains
 time_step                           = 90,
 time_step_fract_num                 = 0,
 time_step_fract_den                 = 7,
 max_dom                             = 3,
 e_we                                = 84,      121, 82
 e_sn                                = 150,     196, 182
 e_vert                              = 28,       28, 28
 num_metgrid_levels                  = 27,
 dx                                  = .233211
 dy                                  = .228236
 p_top_requested                     = 5000.
 ptsgm                               = 42000.,
 grid_id                             = 1,        2, 3
 parent_id                           = 0,        1, 2
 i_parent_start                      = 1,        32, 56
 j_parent_start                      = 1,        38, 76
 parent_grid_ratio                   = 1,        3, 3
 parent_time_step_ratio              = 1,        3, 3
 /
 
 
Thanks in advance for your help!
 
Eduardo Penabad
NWP Department. MeteoGalicia
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