20050713: Trouble Converting NCEP Reanalysis To Gempak


The maximum number of grid times in a GEMPAK grid file is defined by LLMXGT at build time (in $GEMPAK/include/GEMPRM.PRM and
gemprm.h) by default as 1000. It sounds like your grids are every
6 hours (eg 4 per day), so you are hitting 1000 grid times at September 8.

Decode to monthly files rather than a single yearly file.

Steve Chiswell
Unidata User Support

On Wed, 2005-07-13 at 12:13, mpborkow@xxxxxxxx wrote:

I'm trying to convert Daily Global NCEP/NCAR Reanalysis for 2002-2004 to
Gempak using files downloaded from ftp.cdc.noaa.gov.  I'm using a program
that calls DCREANAL to do this.  The trouble is with the surface data.

The data for each year through September 7 is converted fine and it is
useable.  But beginning September 8 of each year, I am not able to access
the grids.  If I take one of the surface files (for instance, pmsl_02.gem
has PMSL for each day/hour in 2002) and run GDINFO setting GDATTIM to any
date prior to September 8 (i.e. GDATTIM = 020625/0000) it will return 1
matching PMSL grid.  If I run it setting GDATTIM to September 8 or any
later date (i.e. GDATTIM = 021015/0000) GDINFO returns "The time
021015/0000 is not found in the data set."  But then I can run GDINFO with
GDATTIM = all, and will find that all the times/dates after September 8
are indeed listed, but for some reason I can just no longer call them
using GDATTIM.

Has anyone ever encountered such a problem or have any suggested
troubleshooting tips?


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