[Happy Monkey]

I'm pretty sure the center of the rainbow is opposite the sun from the observer. To get two rainbow centers, you need two suns, like Tattooine. Or, as explained, a sun and its reflection off of a large body of water.

Multiple rain showers won't help, only the one that is in the right place relative to the sun and the observer will have a rainbow. If they overlap, you'll see more of it, crossing both showers.