[GEMPAK #AZQ-203645]: GEMPAK Color Table

Hi Nick,

The image you attached shows holes for mixing ratio and theta-e, which makes me 
guess it may have to do with the pressure dependency:

from: http://www.unidata.ucar.edu/cgi-bin/gempak/manual/apxB_index

MIXR  Mixing ratio
      MIXR ( DWPC, PRES ) = PR_MIXR ( DWPC, PRES )

THTE  Equivalent potential temperature in Kelvin
      THTE (PRES, TMPC, DWPC) = PR_THTE (PRES, TMPC, DWPC)


Relative humidity would not be dependent on PRES, which is why you see a full 
field.

RELH  Relative humidity
      RELH  ( TEMP, DWPT ) = PR_RELH ( TEMP, DWPT )


Not sure I can provide an exact answer as to why these missing areas area 
present, but it's likely a result of how the grid was created and the 
quality/distribution of observations used to initialize the model (i.e. GEMPAK 
is performing as intended and is displaying what is available).

Without the grid file you're using for this case I can't say more, but would 
suggest you try a few different plots for theta-e, mixing ratio and pressure to 
see if you can view these "holes" in GDCNTR or GDPLOT3. (I'm especially 
interested in a cross-section plot of PRES contours layered on top of MIXR and 
THTE). If you see the holes then that would hint at missing data in the grid.  
If you don't see the holes in plan view or cross-section plots, then that hints 
the problem is isolated to GDCROSS.

Michael James
Unidata


> I am having problems plotting theta-e and mixing ratio using gdcross
> using archived GFS data. There are data holes that show up just for
> those two variables. Relative humidity seems to work as well as
> others, but those two parameters have gaps in the data. Have you seen
> this before? And is this due to the way GEMPAK calculates mixing ratio
> and theta-e. I have attached an example of what I am talking about.
> 
> Thanks
> Nick Nauslar
> 
> 
> 
> 
> 
> 
> 
> 
> 
> On Sep 7, 2010, at 5:27 PM, Unidata GEMPAK Support wrote:
> 
> > Hi Nick,
> >
> > in $GEMTBL/colors/ there is a white background version called
> > "coltbl.xwp_white" - simply copy this to coltbl.xwp (make a backup
> > of coltbl.xwp first) and you should be set.
> >
> > Michael
> > Unidata
> >
> >
> >> Is there a place I can retrieve the coltbl.xwp color table so I can
> >> have white backgrounds on my images?
> >>
> >> Thanks
> >> Nick
> >>
> >>
> >
> >
> > Ticket Details
> > ===================
> > Ticket ID: AZQ-203645
> > Department: Support GEMPAK
> > Priority: Normal
> > Status: Open
> >
> 
> 
> 


Ticket Details
===================
Ticket ID: AZQ-203645
Department: Support GEMPAK
Priority: Normal
Status: Open