According to the US Department of Energy, the main equipment used to predict tornadoes is the Doppler radar system. Doppler radar can measure wind velocity, direction of the wind inside the storm and the predicted rainfall.
Cause of thunderstorms
The intense spinning of a tornado is partly the result of the updrafts and downdrafts in the thunderstorm (caused by the unstable air) interacting with the wind shear, resulting in a tilting of the wind shear to form an upright tornado vortex.
Impact of tornadoes. Like all natural disasters such as hurricanes, earthquakes, floods and others, they end up with massive destruction to homes, property, infrastructure and cause many deaths as well. Each year, about 60 people are killed by tornadoes, mostly from airborne debris.
The "Tri-state tornado"
The most dangerous tornado in the U.S. Killed 695 people and injuring 2,027 people,traveling more than 300 miles through Missouri, Illinois and Indiana. On March 18, 1925 it was rated F5(fajita scale) at the top of the old fajita scale with winds of 260mph.
Preparing for a tornado
1.To begin preparing, you should build an emergency kit and make a family communications plan.
2.Listen to NOAA Weather Radio or to commercial radio or television newscasts for the latest information.
3. Be alert to changing weather conditions.
4Look for the following danger signs:
Dark, often greenish sky
A large, dark, low-lying cloud (particularly if rotating)
Loud roar, similar to a freight train.
5.If you see approaching storms or any of the danger signs, be prepared to take shelter immediately.
The EF Scale (below) is the standard way to measure tornadoes based on wind damage. The original Fujita Scale (or F Scale) was developed by Dr. Theodore Fujita. All tornadoes, and other severe local windstorms, were assigned a number according to the most intense damage caused by the storm.