>> Fascinating indeed! Wonder if this contributed to the Tri-State Tornado of 1925 in terms of how the vortex was structured and it's ability to persist for so long. >>

That's a possibility. One contributing factor for it's exceedingly long track was it's forward speed of 70mph. Actually, if you want to see a modern analog to the 1925 setup, look at March 2nd, 2012.

Sweet will have to check that out about the March 2nd one. I've been interested in the 1925 event as far as the weather conditions and the various research going into it. One thing that surprised me was that the damage track is longer than 219 miles and was readjusted recently to 234 miles after some new leads came up and that it was actually in the warm sector for the duration of it's life.

Could recommend some further reading? I'd interested to know more!

This is a rather neat vid.