What is a tornado?  A tornado is defined as a violently rotating column of air that extends from the base of a cloud to the ground or water.  Not all tornadoes have a visible funnel extending to the ground, although the circulation may be at ground level.  Tornadoes are rated on a scale known as the Fujuta or "F" scale from its creator, Dr. Theordore Fujita from the University of Chicago.  Wind speeds in a tornado can be comparatively weak at less than 100 mph to devastating at over 300 mph giving them their characteristic "freight train" or "jet engine" sound.

Although tornadoes move in any direction, their preferred vector of motion is from southwest to northeast at speeds of 30-40 mph.  Again, there is the exception as tornadoes have been observed to be nearly stationary to moving at speeds in excess of 70 mph.  Tornadoes also occur in every part of the country and can occur at any time during the year.  They cross lakes, rivers, and occur in mountains.  One tornado occurred in the Wyoming mountains at an elevation in excess of 10,000 feet!


What to Do

TORNADO WATCH  A tornado watch is issued when conditions are favorable for the formation of tornadoes in and close to the watch area.  A watch does not mean that a tornado has been sighted.  It means to monitor the weather closely in case of a warning.  Check and review your plan of action should a warning be issued for your immediate area.  A tornado watch box is large rectangular area that covers hundreds or perhaps a few thousand square miles.  Watches are issued by the Storms Prediction Center in Norman, Oklahoma.

TORNADO WARNING  A tornado warning means that a tornado has been sighted, indicated by Doppler radar, or conditions favor tornado formation at any moment.  Warnings are issued by local National Weather Service offices and usually cover a few parishes or counties at a time.  If a tornado warning is issued for your local area, take action immediately!

1.  Move immediately to a small interior room or hallway of the lowest floor and cover yourself with a blanket or mattress if possible.  Contrary to popular belief - DO NOT OPEN WINDOWS!
2.  If an underground shelter is available, go there immediately.  In the deep south, the water table frequently prevents storm shelters from existing.

1.  GET OUT!  Move to a more sturdy form of shelter.  Unfortunately, tornadoes can strike with little or no warning giving the occupants little time to react.  If you are in a mobile home with a tornado in progress, take the same precautions as if you were in a frame home.

1.  Follow the school's plan of action for tornadoes.  In many cases, this action involves lining the edge of the hallways on your knees with your head against the wall and your hands covering the head.
2.  Do NOT take shelter under large spanned roofs such as in a gym or auditorium.  The roofs will likely collapse.
3.  As with the homes, do NOT open windows.

1.  Cars, like mobile homes, provide little or no shelter from tornadoes.  Many people try to outrun the storm in their automobiles only to be trapped in traffic.  Remember that many roads are curved, whereas the tornado will likely take the straight path.
2.  Abandon automobiles for safe shelter.  Lie flat in a ditch or ravine - be cautious of flood waters.
3.  Some people have taken shelter under overpasses.  People have been killed after taking shelter there.  However, as a last resort....

1.  As with the case of automobilies, take shelter in the nearest ditch or low-lying ravine.  Again, keep in mind that heavy rains have likely occurred prior to the tornado producing rapid water run-off.