Tornadoes usually are fast and furious and are over rather quickly so Lois and Clark wouldn't be hiding long - if they even had time to hide. Sometimes there are warnings but it's a rare event when you can actually say a tornado is specifically coming your way. That's unlike a hurricane where you almost always have more of a warning, and, of course, they last much longer. If someone were to write a story, I'd think a hurricane would give a greater opportunity for Lois and Clark to be together longer. Tornadoes are less likely in the northeast US, also, but that doesn't mean they don't happen in those less likely areas. The one that hit Salt Lake City a few years ago is proof of that. (And, oh yes, I know SLC isn't in the northeast US - giggles.)
