Deadly winter tornadoes not rare: NOAA
| Reuters: "Winter tornadoes that ripped across parts of the American South this week were unusually lethal but not particularly rare, a .government meteorologist said on Wednesday as the death toll mounted."
Tornados are a very very localized type of disaster mostly effecting a long but very narrow area. But they are also fairly sudden, now much warning is given if you are not watching the news or have a weather radio. A basement is a good idea if you can.
Severe Weather Safety from NOAA.