You know, it's a whole lot different than it used to be. The radar is so much better. You used to just have to turn on the radio and they relied on spotters. When a tornado is in a rain curtain, you can't always see it and at night, you have to look in the light of the lightning to see the tornado. It was a lot harder to know when to take shelter.
Now, with NOAA weather radios, dopler radar on tv etc, most of the time you know when to take shelter.