[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

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


NOTE: All email exchanges with Unidata User Support are recorded in the Unidata inquiry tracking system and then made publicly available through the web. If you do not want to have your interactions made available in this way, you must let us know in each email you send to us.