Biggest feature added in 0.13.0 is mega wedges: the game now supports tornadoes up to 6.4km / 4 miles wide.
The 1999 Bridge Creek scenario has been improved by cross-referencing with video footage and news coverage.
Finally, the tornadoes no longer rotate at mach 3! I added a minimum rotation rate to the funnels, but didn't realise this resulted in mile-wide tornadoes rotating at 3 times the speed of sound. That has been corrected and a nice side effect of this is the tornadoes visually look a lot better now.