A tornadoes energy per unit of volume is 6 times greater than that of a hurricane. These violent rotating columns of air which develop from thunderstorms are the most violent and deadly storms on earth occurring more often in the United States than anywhere else in the world.
The winds of an F4 or F5 tornado are significantly stronger than the highest category of hurricane with some tornado wind speeds reaching 300+ miles per hour. Some of these monsters can stay on the ground for dozens of miles and cut a path of destruction more than a mile wide. In an average year 800-1000 tornadoes are reported in the United States with at least 20 of those being destructive F4 or F5.
The deadliest long track tornado in history occurred in 1925. The Tri-State tornado touched down on March 18, 1925, at 1:01 p.m. 3 miles NNW of Ellington, Missouri. For 3 1/2 hours this tornado cut a swath of continuous destruction a mile wide across 3 states with average wind speeds of over 300 miles per hour and ground speeds of 62-73 miles per hour. This F5 destroyed 15,000 homes, injured 2,027, and killed 695 before dissipating about 3 miles SW of Petersburg, Indiana at 4:30 p.m.
The sporadic nature and frequency of tornadoes is what makes them so deadly to human life, often touching down with little or no warning. The lead time for a tornado warning is only 11 minutes compared to a 36 hour lead time for a hurricane with roughly 5 hurricanes striking the United States coast in an average 3 year period. Although structural damage is likely, the loss of life can be greatly reduced or avoided with individuals implementing emergency plans and practicing them on a regular basis. Know your safe places and be ready.
Keep an eye on the sky and monitor the National Weather Service broadcasts. If the storms are becoming tornadic before they cross your state line, chances are good they will do the same when entering your state especially if an unstable air mass is in place. Be prepared, when a Tornado WATCH is issued, do not decide to go do some last minute shopping; this could be a serious mistake. Learn the Doppler Radar, when storms are active watch a good meteorologist and learn how to see rotation in a storm. Take storm spotter classes, these classes are free, they only last a couple of hours and the National Weather Service only provides these classes in the spring and fall, you can check out the noaa.gov site to get information. This site also provides many learning tools on the weather and what makes a thunderstorm work, basic storm spotter knowledge and many Flood, Hurricane, and Tornado preparedness publications that can be downloaded.
http://www.education.noaa.gov/cweather.html
http://www.weather.gov/os/brochures.shtml#storm
http://www.nssl.noaa.gov/primer/tornado/tor_faq.shtml
http://www.crh.noaa.gov/pah/?n=1925_tor_ss
