20030905: McIDAS 144hr GFS Grids can be seen, but not accessed

>From: "Corcoran, William T" <address@hidden>
>Organization: SMSU
>Keywords: 200309051955.h85JtNLd015724 McIDAS-X v2003 GFS

Hi Bill,

>Aug. 18 was the last time our map-making programs were able to access
>the 144 hour forecast grids.

Hmm... This corresponds to my installation of McIDAS-X v2003.

>Messing around a bit, I try:
>GRDLIST RTGRIDS/GFS DAY=03248 TIME=0 LEV=500 PARAM=Z NUM=ALL
>and I can see them all the way out to 240 hours including 144 hours

I just verifie dthis.

>BUT
>GRDLIST RTGRIDS/GFS DAY=03248 TIME=0 FHOUR=144 LEV=500 PARAM=Z
>GRDLIST: No grid found matching search conditions

>Perhaps I missed an announcement about how these things are filed?

No.  I think you are the second person to uncover a bug related to
processing of an FHOUR= value being greater than 128.  This sounds
like a requested time is being stored in a char variable in
the server somewhere.  A char is a signed 8-bit quantity, so values
greater than 128 will be treated as negative numbers.

Access to the same GRID field through grid number works with no
problems:

GRDLIST RTGRIDS/GFS DAY=03248 TIME=0 LEV=500 PARAM=Z NUM=ALL
 ...
Dataset position 48     Directory Title= ALL  00Z GFS 96 HR< VT<=120HR
PAR    LEVEL       DAY        TIME    SRC FHOUR     FDAY       FTIME  GRID  PRO
---- --------- ------------ -------- ---- ----- ------------ -------- ----- ----
 ...
Z     500 MB   05 SEP 03248 00:00:00  GFS   144 11 SEP 03254 00:00:00  1034 PS
Z     500 MB   05 SEP 03248 00:00:00  GFS   144 11 SEP 03254 00:00:00  1035 PS
 ...


GRDLIST RTGRIDS/GFS.48 DAY=03248 TIME=0 LEV=500 PARAM=Z GRID=1035
Dataset position 48     Directory Title= ALL  00Z GFS 96 HR< VT<=120HR
PAR    LEVEL       DAY        TIME    SRC FHOUR     FDAY       FTIME  GRID  PRO
---- --------- ------------ -------- ---- ----- ------------ -------- ----- ----
Z     500 MB   05 SEP 03248 00:00:00  GFS   144 11 SEP 03254 00:00:00  1035 PS
Number of grids listed = 1
GRDLIST - done

It seems that my exploration work for the other problem that was
reported should cover yours.  I will let you know when I have found
the problem and implemented a fix.

>Bill
>Dr, William T. Corcoran
>Geography - SMSU
>901 S. National
>Springfield, Missouri 65804
>(417) 836-5781
>http://cirrus.smsu.edu

Tom