You can download the Slovakia 3D precipitation data from the
sample data page ("Slovakia 3D precipitation data set").
For instructions, read the related README file.
Vis5D data viewer
You can also use Vis5D or Vis5d+ to visualize your
3D data set (use r3.out.v5d to export into Vis5D format). VIS5D is a system
for interactive visualization of large 5-D gridded data sets such as those
produced by numerical weather models. One can make isosurfaces, contour line
slices, colored slices, volume renderings, etc of data in a 3-D grid, then
rotate and animate the images in real time. There's also a feature for wind
trajectory tracing, a way to make text anotations for publications, support
for interactive data analysis, etc. Example: 3D silt
distribution