Tornadoes

Outline

Tornadoes

I. Introduction

A. Facts

1. Definition

2. Wind Speeds

3. Damage

4. Number Of Tornadoes Per Year

5. Deaths And Injuries

B. Types Of Tornadoes

1. Weak

2. Strong

3. Violent

C. Average Tornado

1. Variation

a. Waterspout

2. Distance Moved

D. Frequency Of Tornadoes

1. Southern States

2. Northern States

II. Where Tornadoes Come From

A. Energy

1. Thunderstorm

III. Where And When Tornadoes Occur

A. North America

1. Rocky Mountains

2. Appalachian Mountains

B. Other Areas Of The World

C. Spring And Summer

1. When

IV. Damage

A. Wind

1. Materials

2. Animals

3. Explosions

V. Detection Of Tornadoes

A. Doppler Radar

1. SKYWARN

VI. Prediction

A. Atmospheric Conditions

B. Environmental Clues

VII. Staying Safe

A. Safety Rules To Follow

B. Where To Go

1. Storm Shelter

2. Basement

3. Bathroom

4. Closet

C. What To Avoid

1. Windows

2. Driving

Term Paper

Tornadoes

Introduction:

Facts. A tornado is defined as a violently rotating column extending from a thunderstorm to the ground. The most violent tornadoes are capable of tremendous destruction with wind speeds of two hundred and fifty miles per hour or more. Damage paths can be in excess of one mile wide and fifty miles long. In an average year, eight hundred tornadoes are reported nationwide, resulting in eighty deaths and over one thousand five hundred injuries.

Types Of Tornadoes. The average tornado is usually split up into categories based on the strength of the tornado. Most tornadoes, about sixty nine percent (69%), are considered weak, which means they usually last between one minute and ten minutes, have winds less that one hundred and ten miles per hour, and the percent of deaths that occur during these is less than five percent. Strong tornadoes, about twenty nine percent (29%), may last about twenty minutes, have winds between one hundred and ten and two hundred and five miles per hour, and the percent of deaths that are found are about thirty percent of all tornado deaths. The last category for tornadoes is violent ones. With these comes winds greater than two hundred and five miles per hour, they can last about an hour, and have seventy percent of all deaths from tornadoes.

Variations. Some variations of tornadoes are that they can be found in the early stages of rapidly developing thunderstorms. This type of tornado is most common along the range of the Rocky Mountains, the Plains, and the Western States. Tornadoes may appear nearly transparent until dust and debris are picked up. Occasionally, two or more tornadoes may occur at the same time.

Another type of tornado is known as a waterspout. This is a weak tornado that forms over warm water. They are most common along the Gulf Coast and southeastern states. In the western United States, they occur with cold late fall or late winter storms, during a time when you least expect it to develop. They occasionally move inland becoming tornadoes that can cause a great deal of damage and many injuries.

Average Tornado. The average tornado moves from southwest to northeast, but they have been known to move in any direction. The average forward speed is about thirty miles per hour but can vary from that to seventy before it really gets going.

Frequency Of Tornadoes. Tornadoes can occur at any time of the year. In the southeastern states, peak tornado occurrence is March through May, while peak months in the northern states are during the summer months. They are most likely to occur between three and nine o'clock p.m. but have been known to occur at all hours of the day or at night.

Where Tornadoes Come From:

Energy. Tornadoes come from the energy released in a thunderstorm. As powerful as they are, tornadoes account for only a tiny fraction of the energy in a thunderstorm. What makes them dangerous is that their energy is concentrated in a small area, perhaps only a hundred yards across. Not all tornadoes are the same, of course, and science does not yet completely understand how part of a thunderstorm's energy sometimes gets focused into something as small as a tornado.

Where And When Tornadoes Occur:

North America. Whenever and wherever conditions