Re: 20021226: GRD* programs troubles with WINDB (cont.)

Hi Brian and Tom,
Sorry about the late response. I mistakenly filed the messages on this
thread in the wrong folder and didn't get back to them until today. :-(

Anyway, I wanted to say thanks for the bug report. Tom's first GRDLIST
example below shows it clearly. I have filed it as inquiry 11966. As you
said, a workaround would be to run separate GRDCOPYs to grab the 10 M u-
and v-components individually.

Another possible workaround might be to try PAR=U V (instead of
PAR=WINDB) with LEV=10[M]. I wanted to test it here so I could verify
the bug and see if that workaround does the trick, but I can't find any
10 MB grids (or any "above" 100 MB) on our servers so I was unable to
find grids with the same level but different units (M and MB). Not sure
why we don't have those grids (maybe something set in our -XCD config
files?).

I also noticed that the dataset Brian was using is named RTNEW/GFS.
We've had trouble figuring out when the NWS will "officially" rename the
MRF and AVN as the GFS. Please let us know if you guys have any inside
info on such a date, and also if you have suggestions for what -XCD
changes should be made and when. For example, at some point in the near
future I would think it would be best to change dataset names like
RTGRIDS/MRF and RTGRIDS/AVN to RTGRIDS/GFS, and at the same time change
the individual grids' SRC field from AVN or MRF to GFS.

We intend to meet about these upcoming changes sometime soon. But any
help/suggestions we can get from sites is appreciated!

Thanks,
Barry Roth
McIDAS Help Desk
address@hidden

On 12/28/02 09:18 PM, Unidata Support wrote:
>
>>From: "HOETH, BRIAN R. (JSC-ZS) (LM)" <address@hidden>
>>Organization: JSFC
>>Keywords: 200212262131.gBQLVft04686 McIDAS-X GRD*
> 
> Hi,
> 
> I just wanted to expand a little on Brian's note.
> 
> What I found is that GRDDISP/GRDCOPY do not correctly pick out both
> components of 10 meter winds.  The 10 meter U component does correctly
> get chosen, but the 10 mb V wind is used with the 10 m U componet to
> create WINDB.  A GRDLIST from a dataset that contains both 10 m and 10 mb
> winds shows what is going on:
> 
> GRDLIST MYDATA/GRIDS.6010 TIME=0 FHOUR=15 PAR=WINDB LEV=10[M] NUM=ALL
> Dataset position 6010   Directory Title=
> PAR    LEVEL       DAY        TIME    SRC FHOUR     FDAY       FTIME  GRID  
> PRO
> ---- --------- ------------ -------- ---- ----- ------------ -------- ----- 
> ----
> U      10 M    26 NOV 02330 00:00:00  AVN    15 26 NOV 02330 15:00:00   293 
> MERC
> V      10 MB   26 NOV 02330 00:00:00  AVN    15 26 NOV 02330 15:00:00   200 
> MERC
> Number of grids listed = 2
> GRDLIST - done
> 
> The workaround that I sent Brian was to use two invocations
> of GRDCOPY to copy each individual component to a scratch GRID file
> and then run GRDDISP using it.  Individual GRDCOPYs work fine:
> 
> DSSERVE ADD G/G GRID 1 9999 TYPE=GRID "ALL LOCAL GRID FILES
> Adding the group G as a local dataset
> 
> Group/Descriptor         Type  Format & Range     RT Comment
> ------------------------ ----- ------------------ -- --------------------
> G/G                      GRID  GRID 1-9999           ALL LOCAL GRID FILES
> DSSERVE: done
>  
> GRDCOPY MYDATA/GRIDS.6010 G/G.1 PAR=U LEV=10[M]
> Total grids copied=1
> GRDCOPY - done
>  
> GRDCOPY MYDATA/GRIDS.6010 G/G.1 PAR=V LEV=10[M]
> Total grids copied=1
> GRDCOPY - done
> 
> GRDLIST G/G.1 NUM=ALL
> Dataset position 1      Directory Title=
> PAR    LEVEL       DAY        TIME    SRC FHOUR     FDAY       FTIME  GRID  
> PRO
> ---- --------- ------------ -------- ---- ----- ------------ -------- ----- 
> ----
> U      10 M    26 NOV 02330 00:00:00  AVN    15 26 NOV 02330 15:00:00     1 
> MERC
> V      10 M    26 NOV 02330 00:00:00  AVN    15 26 NOV 02330 15:00:00     2 
> MERC
> Number of grids listed = 2
> GRDLIST - done
> 
> GRDDISP G/G.1 PAR=WINDB LEV=10[M] NAV=C PINT=2
> GRDDISP: Done with graphic frame 11
> 
> So, there is a problem with GRDDISP that needs to be attended to.
> 
> Tom
> 
> -------------------- original email from Brian ---------------------------
> 
>>Hello MUG,
>>
>>I have run into an interesting problem with trying to plot the 10 meter
>>winds from the AVN Global GRID data.  I get very intriguing results if I try
>>to do a:
>>GRDDISP RTNEW/GFS TIME=12 FHOUR=6 PAR=WINDB LEV=10[M] DAY=#Y
>>
>>The wind barbs don't look realistic, with values much too large.  Too make a
>>long story short, we (Tom Yoksas) and I have figured out that the problem
>>lies within the GRD* programs not being able to properly distinguish the 10
>>meter winds versus the 10 mb winds for some reason?  It's rather odd.  Check
>>out the attached TFILE (should be able to open with Notepad or Wordpad) that
>>I captured with a bunch of GRDLIST commands.
>>
>>Any thoughts?
>>
>>---------------
>>Brian Hoeth
>>Spaceflight Meteorology Group
>>Johnson Space Center   
>>Ph: 281-483-3246
>>Ops:  281-483-1051