A tornado watch (sometimes referred to as a red box by meteorologists and storm chasers) is issued when conditions are right for a tornado to form. Since any thunderstorm capable of producing a tornado is defined as severe, a tornado watch is also automatically a severe thunderstorm watch. In most cases, the potential exists for large hail and/or damaging winds in addition to the tornadoes.
From Toto to Twister, Storm Chasers to Greensburg, tornadoes have swept into our imaginations. And with good reason: Every year, tornadoes in the United States cause millions of dollars in damage and lead to several severe injuries and even fatalities. D