The above 3D radar image shows a supercell thunderstorm near Abilene, Texas this evening as it reportedly produces hail up to the size of golf balls. The storm has a great structure — a long anvil extending towards the northeast away from the main convection, cloud tops that reach over 40,000 feet, and two cores (main areas of heavy rain and hail) that are split in half by the storm's updraft.
The heaviest rain and hail are located in the dark red and purple areas inside of the thunderstorm, where the dense precipitation is reflecting more of the beam back to the radar itself.
Here is another look at just the hail core with all of the other precipitation filtered out.
Radar software like this one — called GRLevel2 Analyst — are able to make these images by combining all of the different levels scanned by the radar and using algorithms to extrapolate between each level to create a three-dimensional radar image.
[Images via GR2Analyst]