Re: [gembud] max grids

• To: "'Kevin Lux'" <stormpilgrim@xxxxxxxxx>, <gembud@xxxxxxxxxxxxxxxx>
• Subject: Re: [gembud] max grids
• From: "Evan Lowery" <elowery@xxxxxxxxxxxx>
• Date: Tue, 1 Mar 2011 12:21:14 -0500

Kevin,

 

After a GEMPAK grid file is created using nagrib2 or dcgrib2, it's fixed to
that number of grids.  So in your process, you're probably creating a GEMPAK
grid file with 6344 grids using dcgrib2.  You're trying to change the number
of grids using GDDIAG (MAXGRD) which won't work and eventually running out
of grids after a certain number of calculations are done.

 

I'm not completely sure how to increase the number of grids in a grid file
using dcgrib2
(http://www.unidata.ucar.edu/cgi-bin/gempak/manual/decoders_index?dcgrib2),
however I am familiar with doing it in nagrib2
(http://www.unidata.ucar.edu/cgi-bin/gempak/manual/programs_index?nagrib2).
You would set maxgrd=29999 and you'd get a GEMPAK grid file that large.

 

i.e. (converting gfs grib2 data -> GEMPAK grid data)

 

GEMPAK-NAGRIB2>l

GBFILE   = gfs.t00z.pgrbf2011030172.grib2

GDOUTF   = test.grd

PROJ     =

GRDAREA  =

KXKY     =

MAXGRD   = 29999

CPYFIL   = gds

GAREA    = grid

OUTPUT   =

G2TBLS   =

G2DIAG   =

OVERWR   = NO

 

The same logic holds true if you're using nagrib to convert a grib -> GEMPAK
grid file.

 

Regards,

Evan

 

From: Kevin Lux [mailto:stormpilgrim@xxxxxxxxx] 
Sent: Tuesday, March 01, 2011 12:00 PM
To: Evan Lowery
Subject: Re: [gembud] max grids

 

There's a multistep process in the ems_post script that converts from grib1
to grib2 and then to gempak, so I think it's using dcgrib2 for the first and
then nagrib or nagrib2 for the second.  The error mentions nagrib.





On Tue, Mar 1, 2011 at 9:31 AM, Evan Lowery <elowery@xxxxxxxxxxxx> wrote:

Hey Kevin,

 

When you generate the wrf-ems files, how are you converting them to GEMPAK
grid files?  I'm assuming they are originally in a grib or grib2 format and
you're converting them to GEMPAK grid files using nagrib(2) or dcgrib(2). 

 

Evan

 

From: gembud-bounces@xxxxxxxxxxxxxxxx
[mailto:gembud-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Kevin Lux
Sent: Monday, February 28, 2011 4:53 PM
To: gembud@xxxxxxxxxxxxxxxx
Subject: [gembud] max grids

 

I'm running wrf-ems and processing my data to gempak.  I'm also adding some
fields with gddiag, but I'm running into an annoying problem.  The maximum
number of grids gempak can do is about 30,000, but something is setting the
max grids in my file to 6344, so my gddiag script blows up while adding new
grids.  I have no idea where 6344 is being set.  The postprocessing perl
script in the wrf-ems package says 29999, so I'm stumped.  Is 6344 buried
somewhere in the source code?  Changing maxgrd in gddiag doesn't work,
either.

Kevin

 

• References:
  • [gembud] max grids
    • From: Kevin Lux