Why doesn animation work?
The GRIB Viewer is capable of animating data where the same information is repeated for a number of different time intervals, e.g. for pressure or rainfall forecast for the next 0, 6, 12, 18, 24 etc. hours. To enable the program to animate the data, you need to use the “Sort by” box, to sort the data by time, rather than unsorted. The display will change to show a set of times in the left part of the display, and you can click a time slot to show data for that time. Now, the right-click Animate, and the File=>Save animation menus will be enabled.