Brendon, I've attached two source files with changes that should fix this problem. Both of these should be placed in $GEMPAK/source/programs/gui/nwx/ then follow my lead: > cd $GEMPAK/source/programs/gui/nwx/ > make all > ar -r $OS_LIB/nwx.a nwxp_dir.o > ar -r $OS_LIB/nwx.a nwxp_srcho.o > make install then cd out of that dir and run nwx again, let me know if this works for you. FYI surface hourly obs were being handled differently because of the underscore in the filenames (20091031_sao.gem), and a call to split what nwx thought was a string of integers into an array was failing because the string being passed ("20091031_sao") as an integer wasn't. Michael Unidata User Support Ticket Details =================== Ticket ID: QDB-367266 Department: Support GEMPAK Priority: Emergency Status: Open