User blog comment:Streamdapple/Some Questions/@comment-26074320-20170725224602

Hmm, interesting. M3 stands for Mach 33, which is 2301 mph, or 3704 km/h. As for tornado names, it varies between severak terms, usually tornado, whirlwinds or cyclones, although the latter is misleading, and is often confused with tropical cyclones, hency why it's a rare usage to describe a tornado these days