Tornadoes

Wikipedia defines tornado as "a violent windstorm characterized by a twisting, funnel-shaped cloud." The word "tornado" comes from the Spanish or Portuguese verb "tornar," meaning "to turn." The United States has more tornadoes than any other country.

Tornadoes, also called twisters or cyclones, are one of the most deadly weather forces. They are also the most fascinating. Even though tornadoes are usually not more than one mile wide, they leave large areas of destruction and death when they pass.

Tornadoes are actually violent winds that swirl in a counter clockwise direction north of the equator and clockwise south of the equator. Most people think of them as towering black funnels dropping from a large cumulonimbus cloud. The rotation speeds can be up to three hundred miles per hour and sometimes even faster. The air pressure in the center of the tornado is low compared to air pressure on the outside.

The funnel shaped cloud travels in a skip like movement, and usually never lasts for more than a couple of minutes in any one given place. It is because of this skip movement that the tornado leaves some areas wrecked while others a few yards away almost untouched. Certain parts of the world (i.e. Australia, the Midwestern and Southern US) are more prone to have tornadoes. They also occur more frequently in the spring and summer months. Tornadoes usually occur as part of a severe thunderstorm and often come in advance of cold fronts. Sometimes they can also occur less frequently ahead or behind warm fronts.


Picture courtesy of Gene Moore

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