Re: WRF grib2 data

• To: Anthony P Praino <apraino@xxxxxxxxxx>
• Subject: Re: WRF grib2 data
• From: Don Murray <dmurray@xxxxxxxxxxxxxxxx>
• Date: Mon, 14 May 2007 13:18:49 -0600

Hi Anthony-

Don Murray wrote:

What is not clear from your comments is whether this will or will not work with netCDF,

Probably not the WRF netCDF files, but you can try. ;-)  I don't have
any sample WRF netCDF datasets where the times are in separate files.

Thanks to Don Morton at the Arctic Region Supercomputing Center
for providing me some sample netCDF WRF files with one file per
timestep.

The on-the-fly aggregation in IDV 2.2 will not work with these
files because it assumes that the time variable is named "time".
In the netCDF files that Don has, it is called "Time".  However,
you can manually generate an NcML file that looks like:

<netcdf xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2";>
<aggregation type="joinExisting" dimName="Time">
<netcdf location="wrfout_d01_2007-05-14_00-00-00" />
<netcdf location="wrfout_d01_2007-05-14_03-00-00" />
<netcdf location="wrfout_d01_2007-05-14_06-00-00" />
</aggregation>
</netcdf>

which will aggregate the files.

One note about the WRF netCDF files.  We encourage people to use the
WRF-POST program to convert these to GRIB.  The overhead of the
grid staggering is quite substantial in the IDV in terms of memory
and computation.  You also get many more derived parameters than
from the raw netCDF output.  But, we understand that some want to
look at the data in the grid coordinates.

Don
*************************************************************
Don Murray                               UCAR Unidata Program
dmurray@xxxxxxxxxxxxxxxx                        P.O. Box 3000
(303) 497-8628                              Boulder, CO 80307
http://www.unidata.ucar.edu/staff/donm
*************************************************************

• References:
  • Re: WRF grib2 data
    • From: Anthony P Praino
  • Re: WRF grib2 data
    • From: Don Murray