As part of my research, I have to create a precipitation grid using weather stations data. I'm using Geostatistical Analyst to interpolate these data. I tested different methods (IDW, SK, UNK, ORK, and OCK) with and without data trends removal, and after analyze the statistics of these methods I chose OCK. My precipitation grid looks pretty good, but when I export the data to create a raster file (GA Layer to Grid), this file looks awful. I've seen other people having this same issue, and when they ask similar question, the answer is normally that this is not an issue. Well, although I understand it may be "normal", I really want to have a precipitation that looks more professional rather than a messed image. Is there any way to make this grid look smoother? How these institutions create these nice grid (e.g. PRISM)? Do they use other technique that I'm not aware about?
Please see below two images of my precipitation grid, one is the contour file (OCK) and the other is the raster after conversion.
Thank you very much,