Emergency Online

TORNADO

A tornado is considered nature's most violent storm. It can be seen as a rotating column of air that is in contact with the ground and the clouds.  It appears more like a funnel-shaped cloud that extends to the ground. Tornadoes come in many sizes.  Most tornadoes have wind speeds between 40 and 110 miles per hour and about 250 feet across, traveling a few miles before dissipating.  Some tornadoes have wind speeds of more than 300 miles per hour, stretching more than a mile across.  In a matter of seconds, tornadoes can cause fatalities and destroy neighborhoods. 

Tornadoes mostly occur in the United States.  Other places where tornadoes commonly occur are in Southern Canada, South-Central and eastern Asia, East-Central South America, Southern Africa, northwestern and southwestern  Europe, western and southeastern Australia and New Zealand. Peak tornado season in the Southern States is March through may.  In the northern States, it is around late spring through early summer. They are most likely to occur between 3 p.m. and 9 a.m. but can also occur at any time.

Indications of an Approaching Tornado

Before a tornado hits, the wind may die down and the air may become very still. Even if a funnel is not actually visible, a cloud of debris can mark its location.  Tornadoes generally occur near the trailing edge of a thunderstorm. It is common to see clear, sunlit skies behind a tornado.

• Dark, often greenish sky
• Large hail
• A large, dark, low-lying cloud (particularly if rotating)
• Loud roar, similar to a freight train.

Types of Tornadoes

• Multiple Vortex - two or more columns of spinning air rotate around a common center. It is often observed in intense tornadoes.
  
• Satellite -  a weaker tornado which forms very near a large, strong tornado contained without the same mesocyclone.  It appears to orbit the larger tornado
  
• Waterspout is a tornado over water. 
  
• Landspout (or Dust-tube) is similar to that of a waterspout forming as the winds swirl at the surface.  Initially, it would appear in the form of a  debris cloud. As the tornado matures, the debris is pulled up into the cloud base. Only then it would be visible from the cloud base to the ground.
  
• Supercell - tornadoes that develop from supercell thunderstorms.  Supercell thunderstorm has a low-hanging, rotating layer of cloud known as a "wall cloud". It looks somewhat like a layer of a layer cake that hangs below the broader cloud base. One side of the wall cloud is often rain-free, while the other is neighbored by dense shafts of rain. The rotating updraft of the supercell is seen on radar as a “mesocyclone.”
  

• If your immediate area (geographic location) is under a tornado warning, you and your family should seek a safe shelter immediately!
• If you are in your home or any other structure such as a building or store for example, go to a pre-designated shelter area such as a safe room, basement, storm cellar, or the lowest building level. If there is no basement, go to the center of an interior room on the lowest level (closet, interior hallway) away from corners, windows, doors, and outside walls. Put as many walls as possible between you and the outside. Get under a sturdy table and use your arms to protect your head and neck. Do not open windows.
• If you are in a vehicle, trailer, or mobile home -  Get out immediately and go to the lowest floor of a sturdy, nearby building or a storm shelter. Mobile homes, even if tied down, offer little protection from tornadoes.
• If you are outside, lie flat in a nearby ditch or depression and cover your head with your hands. Be aware of the potential for flooding.
• Do not get under an overpass or bridge. You are safer in a low, flat location.
• Never try to outrun a tornado in urban or congested areas in a car or truck. Instead, leave the vehicle immediately for safe shelter.  Watch out for flying debris. Flying debris from tornadoes causes most fatalities and injuries.