CDO

Dear all,

I was trying to regrid the data that I have from WRF outputs.
However, I met following warning and an error:

Warning (cdfScanVarAttr): NetCDF: Variable not found - >XLONG_U<
Warning (cdfScanVarAttr): NetCDF: Variable not found - >XLAT_U<
Warning (cdfScanVarAttr): NetCDF: Variable not found - >XTIME<
Warning (cdfScanVarAttr): NetCDF: Variable not found - >XLONG_V<
Warning (cdfScanVarAttr): NetCDF: Variable not found - >XLAT_V<
Warning (cdfScanVarAttr): NetCDF: Variable not found - >XLONG<
Warning (cdfScanVarAttr): NetCDF: Variable not found - >XLAT<
cdo remapbil (Abort): Unsupported generic coordinates (Variable: U)!

I am aware that the warning can be ignored, but I do not know why this error occurred.

The NetCDF information is:

dimensions:
Time = UNLIMITED ; // (1 currently)
DateStrLen = 19 ;
west_east_stag = 2050 ;
south_north = 1749 ;
bottom_top = 48 ;
west_east = 2049 ;
south_north_stag = 1750 ;
bottom_top_stag = 49 ;
variables:
char Times(Time, DateStrLen) ;
float U(Time, bottom_top, south_north, west_east_stag) ;
U:FieldType = 104 ;
U:MemoryOrder = "XYZ" ;
U:description = "x-wind component" ;
U:units = "m s-1" ;
U:stagger = "X" ;
U:coordinates = "XLONG_U XLAT_U XTIME" ;

....
// global attributes:
:TITLE = " OUTPUT FROM WRF V4.2.1 MODEL" ;
:START_DATE = "2018-05-25_12:00:00" ;
:WEST-EAST_GRID_DIMENSION = 2050 ;
:SOUTH-NORTH_GRID_DIMENSION = 1750 ;
:BOTTOM-TOP_GRID_DIMENSION = 49 ;
:DX = 4000.f ;
:DY = 4000.f ;
:AERCU_OPT = 0 ;
:AERCU_FCT = 1.f ;
:IDEAL_CASE = 0 ;
:DIFF_6TH_SLOPEOPT = 0 ;
:AUTO_LEVELS_OPT = 2 ;
:DIFF_6TH_THRESH = 0.1f ;
:DZBOT = 50.f ;
:DZSTRETCH_S = 1.3f ;
:DZSTRETCH_U = 1.1f ;
:GRIDTYPE = "C" ;
:DIFF_OPT = 1 ;
:KM_OPT = 4 ;
:DAMP_OPT = 0 ;
:DAMPCOEF = 0.2f ;
:KHDIF = 0.f ;
:KVDIF = 0.f ;
:MP_PHYSICS = 10 ;
:RA_LW_PHYSICS = 4 ;
:RA_SW_PHYSICS = 4 ;
:SF_SFCLAY_PHYSICS = 1 ;
:SF_SURFACE_PHYSICS = 2 ;
:BL_PBL_PHYSICS = 1 ;
:CU_PHYSICS = 0 ;
:SF_LAKE_PHYSICS = 0 ;
:SURFACE_INPUT_SOURCE = 1 ;
:SST_UPDATE = 1 ;
:GRID_FDDA = 0 ;
:GFDDA_INTERVAL_M = 0 ;
:GFDDA_END_H = 0 ;
:GRID_SFDDA = 0 ;
:SGFDDA_INTERVAL_M = 0 ;
:SGFDDA_END_H = 0 ;
:HYPSOMETRIC_OPT = 2 ;
:USE_THETA_M = 1 ;
:GWD_OPT = 0 ;
:SF_URBAN_PHYSICS = 0 ;
:SF_SURFACE_MOSAIC = 0 ;
:SF_OCEAN_PHYSICS = 0 ;
:WEST-EAST_PATCH_START_UNSTAG = 1 ;
:WEST-EAST_PATCH_END_UNSTAG = 2049 ;
:WEST-EAST_PATCH_START_STAG = 1 ;
:WEST-EAST_PATCH_END_STAG = 2050 ;
:SOUTH-NORTH_PATCH_START_UNSTAG = 1 ;
:SOUTH-NORTH_PATCH_END_UNSTAG = 1749 ;
:SOUTH-NORTH_PATCH_START_STAG = 1 ;
:SOUTH-NORTH_PATCH_END_STAG = 1750 ;
:BOTTOM-TOP_PATCH_START_UNSTAG = 1 ;
:BOTTOM-TOP_PATCH_END_UNSTAG = 48 ;
:BOTTOM-TOP_PATCH_START_STAG = 1 ;
:BOTTOM-TOP_PATCH_END_STAG = 49 ;
:GRID_ID = 1 ;
:PARENT_ID = 0 ;
:I_PARENT_START = 1 ;
:J_PARENT_START = 1 ;
:PARENT_GRID_RATIO = 1 ;
:DT = 16.f ;
:CEN_LAT = 48.00001f ;
:CEN_LON = -98.f ;
:TRUELAT1 = 30.f ;
:TRUELAT2 = 60.f ;
:MOAD_CEN_LAT = 48.00001f ;
:STAND_LON = -107.f ;
:POLE_LAT = 90.f ;
:POLE_LON = 0.f ;
:GMT = 12.f ;
:JULYR = 2018 ;
:JULDAY = 145 ;
:MAP_PROJ = 1 ;
:MAP_PROJ_CHAR = "Lambert Conformal" ;
:MMINLU = "MODIFIED_IGBP_MODIS_NOAH" ;
:NUM_LAND_CAT = 21 ;
:ISWATER = 17 ;
:ISLAKE = 21 ;
:ISICE = 15 ;
:ISURBAN = 13 ;
:ISOILWATER = 14 ;
:HYBRID_OPT = 2 ;
:ETAC = 0.2f ;
}

I used " cdo remapbil,lonlat cstm_d01_2018-05-25_12_00_00 test.nc" to do the remap.

the info for lonlat file is:
gridtype = lonlat
xsize = 9486
ysize = 3940
xfirst = 172.89740
xinc = 0.01801802
yfirst = 7.57129
yinc = 0.01801802

I am not sure why it shows a generic coordinate since the projection is Lambert. Any suggestions are much appreciated.

Thanks,
Hao