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[GEMPAK #TUL-228048]: error in gdinfo

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  • Subject: [GEMPAK #TUL-228048]: error in gdinfo
  • Date: Tue, 15 Aug 2006 10:15:59 -0600
The scan mode flags in the GRIB data are supposed to tell teh decoder which 
direction the grid is oriented
(eg, points from top to bottom N/S or bottom to top).

The Grid #002 is a WMO standard definition that the decoder decodes many 
real-time feeds in, so it sounds 
like the scan mode flags of your grib are not as expected.
If needed, I can look at the grid to see if the decoder is behaving properly.

Steve Chiswell
Unidata User Support


> > Dear Mr Chiswell,
> >
> > I found the error. If I plot the temperature conturs on a global scale I see
> > that the grid is upside down. North and South on the map are at different
> > places compared to North and South on my grid which are the temperatures on.
> > That explains why my temperatures are too cold. I was looking at the 
> > northern
> > hemisphere on the map but at the same time looking at temperature values of
> > the southern hemisphere.
> > When could that have happend? During converting .grb to .grd with dcgrib2?
> > Could this be a problem with the header of my grib file?
> >
> > Kathrin
> >
> > Am Mittwoch, 9. August 2006 00:25 schrieb Unidata GEMPAK Support:
> > > Kathrin,
> > >
> > > IU'd have to see your input to gdinfo and its output listing to know what
> > > the GDU error is referring to. It might be that the GFUNC isn't present to
> > > a time or specified level.
> > >
> > > If you want to post your decoded GEMPAK file, I'll take a look at that 
> > > too.
> > >
> > > Any information about what the temperature field is "off" would be useful.
> > > If it is a scaling issue, eg 10**scale, then it may just be a units
> > > conversion, otherwise, I can't say yet.
> > >
> > > Steve Chiswell
> > > Unidata User Support
> > >
> > > > Dear Gempak support team,
> > > >
> > > > I am using nsharp with ERA40 datasets. I have 6 parameters (TMPK, RELH,
> > > > geopotential hight, u wind component, v wind  component and w wind
> > > > component) on 15 pressure level on a global grid. Nsharp seems to work
> > > > perfectly. My only problem is the temperature. It is too cold. Much too
> > > > cold. gdinfo gives me two error messages:
> > > > [GDU 2]  Did not find any matching grids.
> > > > and
> > > > GRID ANALYSIS BLOCK:
> > > > UNKNOWN ANALYSIS TYPE
> > > > Could these have something to do with my cold temperatures?
> > > >
> > > > Any help would be appreciated,
> > > > Kathrin Riemann
> > >
> > > Ticket Details
> > > ===================
> > > Ticket ID: TUL-228048
> > > Department: Support GEMPAK
> > > Priority: Normal
> > > Status: Closed
> >
> >
> 


Ticket Details
===================
Ticket ID: TUL-228048
Department: Support GEMPAK
Priority: Urgent
Status: Closed