Re: [idvusers] Problem using NARR-A as aggregated GRIB files in IDV

• To: taxelrod@xxxxxxxx
• Subject: Re: [idvusers] Problem using NARR-A as aggregated GRIB files in IDV
• From: Don Murray <dmurray@xxxxxxxxxxxxxxxx>
• Date: Wed, 26 Sep 2007 13:38:14 -0600

Hi Tim-

Tim Axelrod wrote:

I'd like to be able to use a set of NARR-A grb files as a data source to
IDV and be able to display them as an animation and/or use the data
probe/time series tool.   I'm able to do this with NAM grb files by
selecting "aggregated GRIB files" as the data source type.   This fails
with the NARR-A grb files, however.   Only a single time gets shown in the
field selector/times window - and that time seems to be randomly selected
from the set of files.

This is not possible at present but a solution is being worked on
in the underlying netCDF-Java layer.  But that won't be available
for a few months.

The NAM works because they all have the same model run time and each
file has an offset forecast hour.  Each NARR file has a different
base ("model run") time with a forecast hour of 0, so the aggregation
doesn't know what to use as a "model run" time.

I'm using IDV 2.3, build data 2007-08-15.  Any advice?

If you are daring, you could run the nightly build which has
formula in it for making a time sequence from a set of single time
images or grids.  What you would do is select all the NARR files you
want to "aggregate" and use the I'm Feeling lucky option in the

allows you to select the individual grids. This will be time consuming
if you have a lot of files.  It's a a new feature (multiple parameter
selection), so feedback is welcome.

The nightly build is available at:

http://www.unidata.ucar.edu/software/idv/release/nightly

Don Murray
*************************************************************
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:
  • [idvusers] Problem using NARR-A as aggregated GRIB files in IDV
    • From: Tim Axelrod