Tempest

Tempest! is a audio and video thunderstorm experience generator that can optionally be installed as a screensaver.

Run as a stand-alone application, it plays back footage of lightning strikes in various settings, accompanied by the sounds of rain and thunder.

The three elements of lightning, rain, and thunder can be controlled in different ways. While it's not explicitly stated what factors these controls influence, it seems that adjusting the slider controls for "Lighting [sic] Intensity", "Thunder Ferocity", and "Rain Frequency" changes the frequency of video and sound snippet playback. Volume can be adjusted for rain and thunder independently, making it possible to eliminate one or the other if desired. It's also possible to omit the video while still using your computer, since closing the Tempest! window alone does not halt sound playback.

The program was a bit buggy for me, quitting unexpectedly on launch every so often. The thunder doesn't seem line up to the lightning at all, and I also don't like the way scene changes frequently - both in terms of the lightning vantage point and rainfall sound. Putting these under user control would improve things vastly.