Hi Ravi, Your questions are beyond the scope of the type of support that Unidata supplies, these are questions for you to discuss with a Meteorologist or to research yourself. Ethan has supplied urls to references to the ruc data providers below so you can ask questions there. There is a wealth of information on the internet too, including on line courses. Unidata has very limited resources so we concentrate more on the data manipulation level. Robb... Ticket Details =================== Ticket ID: QDJ-903556 Department: Support netCDF Java Priority: Normal Status: Open