[gembud] gdgrib - setting subcenter = 0

• To: gembud@xxxxxxxxxxxxxxxx
• Subject: [gembud] gdgrib - setting subcenter = 0
• From: Mike.Hardiman@xxxxxxxx
• Date: Sat, 08 Mar 2008 15:20:57 -0600 (GMT)

Hey all,

I'm trying to create a GRIB file using GDGRIB, which calculates the 3-hr
QPF from the Canadian GEM (Regional) model's run-accumulated precip
fields.  Everything looks good, but for some reason, I can't get gdgrib
to set PDS byte 26 (subcenter) to zero.  

If I set VERCEN = 2/54/36/0  ... I still get subcenter=5 when running wgrib.
If I set byte 26 to anything else, say "3," then the subcenter appears
as indicated when running wgrib.

Here's the 'wgrib -V' output from one of the original GRIB files, which
in this case contains 0-21hr QPF:

rec 6:69416:date 2008030700 APCP kpds5=61 kpds6=1 kpds7=0 levels=(0,0)
grid=255 sfc 0-21hr acc:
  APCP=Total precipitation [kg/m^2]
  timerange 4 P1 0 P2 21 TimeU 1  nx 135 ny 95 GDS grid 5 num_in_ave 0
missing 0
  center 54 subcenter 0 process 36 Table 2 scan: WE:SN winds(grid)
  polar stereo: Lat1 27.203000 Long1 -135.213000 Orient 249.000000
     north pole (135 x 95) Dx 60000 Dy 60000 scan 64 mode 136
  min/max data 0 151.5  num bits 9  BDS_Ref 0  DecScale 0 BinScale -1



Here's output from my GDGRIB-generated grib file, with VERCEN=2/54/36/0
Note that the center, process, and table all match the original GRIB,
but not the subcenter.  

rec 2:24130:date 2008030712 APCP kpds5=61 kpds6=1 kpds7=0 levels=(0,0)
grid=255 sfc 45-48hr acc:
  APCP=Total precipitation [kg/m^2]
  timerange 4 P1 45 P2 48 TimeU 1  nx 135 ny 95 GDS grid 5 num_in_ave 0
missing 0
  center 54 subcenter 5 process 36 Table 2 scan: WE:SN winds(grid)
  polar stereo: Lat1 27.203000 Long1 -135.213000 Orient 249.000000
     north pole (135 x 95) Dx 60000 Dy 60000 scan 64 mode 8
  min/max data 0 23  num bits 15  BDS_Ref 0  DecScale 3 BinScale 0



And for just for grins, here's my input into GDGRIB:

 GDFILE   = precip48.gem + precip45.gem
 GFUNC    = SUB(P48M,P45M+2^f045)
 GDATTIM  = last
 GLEVEL   = 0
 GVCORD   = none
 GBTBLS   = GEMTBL/grid/wmogrib2.tbl
 GBFILE   = qpf48.grb
 VERCEN   = 2/54/36/0
 PDSVAL   = P03M
 PRECSN   =
 WMOHDR   =
 CPYFIL   =
 PROJ     =
 GRDAREA  =
 KXKY     =

Note: I have also tried using one of the original GRIB
files-converted-to-GEMPAK as a "CPYFIL" ... but this did not affect the
PDS parameters.

Anyone know how to force GDGRIB to accept "0" as a subcenter?

Thanks,
-Mike Hardiman