<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Hi George,<div class=""><br class=""></div><div class="">I don’t know whether what Alex mentioned below helped, but I think you just need to get your indices right within the loop. See the attached script and the resulting output file. Compare the script to your original script. I hope that’s the kind of output you are looking for. It is just what Will Hobbs and Karin suggested earlier.</div><div class=""><br class=""></div><div class="">Please, as mentioned elsewhere, the most efficient way of using ncl is to, first try and understand the content of your data file and always read the documentation of the available functions.</div><div class=""><br class=""></div><div class="">Jack.</div><div class=""><br class=""></div><div class=""></div></body></html>