Weather - Tornadoes

By: Jericho Dixon and Kory Tompkins

What Are Tornadoes?

Tornadoes are one of the most violent and powerful types of weather. They consist of a very fast rotating column of air that usually forms a funnel shape. They can be very dangerous as their high speed winds can break apart buildings, knock down trees, and even toss cars into the air

How Tornadoes FormTornadoes tend to form from very tall thunderstorm cloud called a cumulonimbus clouds. The typical steps to form a tornado are:1. A large thunder storm occurs in a cumulonimbus cloud2. Fast cold air at a high altitude is forced across warm air from the ground3. The air between the cold and warm air begins to swirl horizontally4. Warm air from the ground pushes up on the swirling air and tips it over 5. The funnel of swirling air begins to suck up more warm air from the ground 6. The funnel grows longer and stretches toward the ground 7. When the funnel touches the ground it becomes a tornado

. The funnel of swirling air begins to suck up more warm air from the ground

Characteristics Of A Tornado* Shape – Tornadoes typically look like a narrow reaching from the clouds down to the ground. Sometimes giant tornadoes can look more like a wedge.* Size – Tornadoes can vary widely in size. A typical tornado in the United States is around 500 feet across, but some may be as narrow as just a few feet across or as large as a mile wide.* Wind Speed – The wind speed of a tornado can vary from 65 to 250 miles per hour.* Color – Tornadoes may appear different colors depending on the local environment. Some may be nearly invisible, while others may appear white, gray, black, blue, red, or even green.* Rotation – When viewed from above, most tornadoes rotate counterclockwise in the northern hemispheres and clockwise in the southern hemisphere.

Types of Tornadoes Supercell - A supercell is large long -lived thunderstorm. It can produce some of the largest and most violent tornadoes. Waterspout- A waterspout forms over warm water. They usually dissipate when they hit land. Land Spout – A land spout is similar to a waterspout but on land. It is week and is not associated with a vortex of air from a thunderstorm.

Gustnado - A small tornado formed at a weather front by gust of wind. Multiple Vortex - A tornado with more then one spinning tube of

air.

Tornado Categories

Category Wind Speed Strength

EF-0 65-85 MPH WeakEF-1 86-110 MPH WeakEF-2 111-135 MPH StrongEF-3 136-165 MPH StrongEF-4 166-200 MPH ViolentEF-5 over 200 MPH Violent

Tornadoes are categorized by their wind speed and the amount of damage they cause using a scale called the “Enhanced Fujita” scale. It is usually abbreviated as the ”EF” scale.

Where Do Most Tornadoes Occur?

Tornadoes can form most anywhere, but most of the tornadoes in the United States occur in an area called Tornado Alley. Tornado Alley stretches from northern Texas to South Dakota and from Missouri to the Rocky Mountains.

Works Citedhttp://www.bing.com/images/search?q=cool+looking+tornado&FORM=HDRSC2&adlt=strict#view=detail&id=C2AD41C66A463158488BAB424AC1396B197F437C&selectedIndex=55

http://www.ducksters.com/science/earth_science/tornadoes.php