20030625: problem with GRDCOPY (cont.)

>From: Owen Cooper <address@hidden>
>Organization: Aeronomy Laboratory/NOAA
>Keywords: 200306251740.h5PHeMLd017765 McIDAS-X GRDCOPY

Hi Owen,

Sorry I couldn't get to this inquiry yesterday, but I was in a workshop
all afternoon.

>Your quick fix worked just fine, but now I've run into one more problem 
>that I hope you can help me solve if it won't take too much time.
>
>Running the following commands I can not derive ABV:
>
>GRDCOPY RTGRIDS/AVN MYDATA/GRIDS.1 PAR=U V Z T DAY=176 TIME=12 FHOUR=6 
>GPRO=MERC LEV=400 300 250  NUM=ALL SUBSECT=0 90 DEL=YES MAX=1065
>Total grids copied=12                                                         
>                                                               
>GRDCOPY - done
>
>GRDCOPY RTGRIDS/AVN MYDATA/GRIDS.1 DERIVE=ABV DAY=176 TIME=12 FHOUR=6
>GPRO=MERC LEV=300 SUBSECT=0 90
>GRDCOPY: No grid found matching search conditions
>
>GRDCOPY - done

I tried the same thing and got the same result.  I also tried being explicit
with the fields to get use of MATH= and got the same thing:

GRDCOPY RTGRIDS/AVN MYDATA/GRIDS.1 G1='PARAM U;LEV 300;DAY 176;TIME 12;FHOUR 
6;GPRO MERC' G2='PARAM V' MATH='DDX(G2)-DDY(G1)+COR' NEWPAR=ABV SUBSECT=0 90 
TRACE=1
GRDCOPY: Set of grids to make grid is incomplete
GRDCOPY - done
GRDCOPY failed, RC=1

I added the tracing so I could see what is happening on the server side.
The problem appears to be that the server loses track of the second grid
to be used just before it is to be read.  That is why the message is
coming back that the set of grids is incomplete.

Exactly why this is happeing, I don't know.  I will be searching the
McIDAS User Group archives for any other reports of this failure to
see if a fix has been developed.  It it has, it will be on the server
side, so the mod(s) will need to be made there.  What ADDE server are
you accessing for the RTGRIDS dataset?

>I don't understand why this fails becuase the u and v wind components
>are there:

You are right.  This is a bug.

>GRDLIST MYDATA/GRIDS.1 NUM=ALL
>
>Dataset position 1      Directory Title= IPV work grid
>PAR    LEVEL       DAY        TIME    SRC FHOUR     FDAY       FTIME GRID  PRO
>---- --------- ------------ -------- ---- ----- ------------ -------- ----- --
> --
>T     400 MB   25 JUN 03176 12:00:00  AVN     6 25 JUN 03176 18:00:00     1 ME
> RC
>T     300 MB   25 JUN 03176 12:00:00  AVN     6 25 JUN 03176 18:00:00     2 ME
> RC
>T     250 MB   25 JUN 03176 12:00:00  AVN     6 25 JUN 03176 18:00:00     3 ME
> RC
>U     400 MB   25 JUN 03176 12:00:00  AVN     6 25 JUN 03176 18:00:00     4 ME
> RC
>U     300 MB   25 JUN 03176 12:00:00  AVN     6 25 JUN 03176 18:00:00     5 ME
> RC
>U     250 MB   25 JUN 03176 12:00:00  AVN     6 25 JUN 03176 18:00:00     6 ME
> RC
>V     400 MB   25 JUN 03176 12:00:00  AVN     6 25 JUN 03176 18:00:00     7 ME
> RC
>V     300 MB   25 JUN 03176 12:00:00  AVN     6 25 JUN 03176 18:00:00     8 ME
> RC
>V     250 MB   25 JUN 03176 12:00:00  AVN     6 25 JUN 03176 18:00:00     9 ME
> RC
>Z     400 MB   25 JUN 03176 12:00:00  AVN     6 25 JUN 03176 18:00:00    10 ME
> RC
>Z     300 MB   25 JUN 03176 12:00:00  AVN     6 25 JUN 03176 18:00:00    11 ME
> RC
>Z     250 MB   25 JUN 03176 12:00:00  AVN     6 25 JUN 03176 18:00:00    12 ME
> RC
>Number of grids listed = 12
>
>GRDLIST - done
>
>Notice that I was using the 6 hour forecast data.  If I use the 0 hour
>forecast data then I can successfully derive ABV.

I didn't thry this, so I will take your word for it.

>Any ideas on this puzzling scenario?

It is a bug, and I will look to see if there is a fix for it.

>thanks again

Sorry about the delay.

Tom