I am aware that I could simply graph them as three different series, however this solution scales terribly when trying to represent many such series on the same graph. Do I really need to pull the data out of splunk and use another graphing program?
you can easily show the lines you want with a line chart -- here's a blog post with examples and links to the commands for doing so. blogs.splunk.com/2012/11/04/predict-detect/
to visualize the data with something more advanced than a line chart you'll need to look into how to leverage other visualization libraries in Splunk; I know there are examples in some apps, but I can't talk to how they work.