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Questions on creating grids

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  • Subject: Questions on creating grids
  • Date: Tue, 13 May 2003 17:09:51 -0500
Hey there,

Last time I wrote I was trying to create the hourly surface LI from the
observed 12Z and 00Z 500 mb temps. Well, I have got that figured out and
running pretty good. I am now into the next phase of trying to update
the hourly surface LI's. I would like to use the ETA and the RUC to give
me 500 mb temp grids at different intervals and then use that in place
of the observed 500 mb temp grids . This should give me a a better
representation of the hourly surface LI.   As I said at first, the
script runs good in creating the hourly surface LI with the observed 500
mb temps. I doi have to create it as a vgf file because I am not sure
how  to go about incorporating the part of the script that does the
time/data calculations into a restore file (.nts).  So I am stuck with
the vgf format for now.

But I have gotten off course just a little bit. I used the program
GDCFIL to create a file(s) which I called "eta or ruc.grd".  This file
is the one in which I will store my 500 mb temperatures for that
particular model. and then run the calculation with that grid instead of
the observed temp grid.  Well, I have it mostly but I am having a
problem with the GDATTIM part.  for instance my eta grid is stored as
YYMMDDHH_eta_211.gem.  When I tried GDATTIM the first time I thought I
could just put in the date and time (ie; 12/11).  Then I realized it was
looking for the forecast time of the grid. So with the ETA when it is
asking me for a time I am putting in F06 for GDATTIM.  That worked and
the grid was created. However, the problem is in how the grid is
stored.  It says when I looked at the grid with GDINFO that the grid
(which I named ETMPC) was dated as 030511/12F006.  That is where my
problem is because of how the grid is dated. Is there a way to get
around this? I thought I could just create this grid and subsititute in
ETMPC for the TMPC in the regular script. But that doesn't seem to be
working. I am wondering if there is any "operator error" involved in
this whole process.

Also, is there a way to make this LI script a restore file?  I have
tried but it doesn't like the setting of the different variables(ie,
day, hour, etc).

Thanks.

Kevin Polston
Senior Instructor, NWSTC
Kansas City MO 64152

816-880-9314 ext 273