Brian, The problem is an array size limitation on the number of tics being drawn in the terrain. As an immediate (eg no code change needed) fix, you can set IJSKIP=1, which will decrease the number of points by interpolation. I have fixed/improved the code and can provide you with a new binary or source code depending on what you need. Steve Chiswell Unidata user Support Ticket Details =================== Ticket ID: FYS-891494 Department: Support GEMPAK Priority: Normal Status: Closed