making

[Jason Snyder]

I have a NetCDF data set that is a composite of wind data based on certain
phases of the Madden Julian Oscillation and I was interested in looking at
the backwards trajectories of air parcels coming into Lake Tahoe in such a
scenario.  I have been trying to work with the script traj.gs, but GrADS
said that TDEF is undefined.  I was then told that I need to use a .ctl
file, but how do I convert data in NetCDF format to that that can be used
in a .ctl file which I would need to run the script traj.gs.  Someone
suggested that I use Use xconv utility, which has the website:
http://badc.nerc.ac.uk/help/software/xconv/

However, I could not figure out how to use this program to convert a
NetCDF file to a .ctl file.  Can someone show me how to use this program,
or some other ways to obtained .ctl files that I could use in running the
traj.gs script?

Thanks,

Jason