write summary writing: Before a tornado hits, the wind may die down and the air may become very still. A cloud of de brbris can mark the location of a tornado even if a funnel is not visible . Tornadoes generally occur near the trailing edge of a thunderstorm. It is not uncommon to see clear , sunlit skies behind a tornado. They may strike quickly , with little or no warning. The average tornado moves southern to northeast , but they have been known to move in any direction. the average forward speed of a tornado is 30mph, but may vary from stationary to 70 mph . Tornadoes can accompany tropical storms and hurricanes as they move onto land( word limit -- 80 to 100
Answers
Tornadoes are vertical funnels of rapidly spinning air. Their winds may top 250 miles an hour and can clear a pathway a mile wide and 50 miles long.
Also known as twisters, tornadoes are born in thunderstorms and are often accompanied by hail. Giant, persistent thunderstorms called supercells spawn the most destructive tornadoes.
These violent storms occur around the world, but the United States is a major hotspot with about a thousand tornadoes every year.
"Tornado Alley," a region that includes the area in the eastern state of South Dakota, Nebraska, Kansas, Oklahoma, northern Texas, and eastern Colorado, is often home to the most powerful and destructive of these storms. U.S. tornadoes cause 80 deaths and more than 1,500 injuries per year.
What is a tornado?
A tornado is a violently rotating column of air that extends from a thunderstorm to the ground. It's often portended by a dark, greenish sky. Black storm clouds gather. Baseball-size hail may fall. A funnel suddenly appears, as though descending from a cloud. The funnel hits the ground and roars forward with a sound like that of a freight train approaching. The tornado tears up everything in its path.
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TORNADOES 101
Tornadoes are some of the most destructive forces of nature. Learn how tornadoes form, how they are rated, and the country where the most intense tornadoes occur.
Every U.S. state has experienced twisters, but Texas holds the record: an annual average of 120. Tornadoes have been reported in Great Britain, India, Argentina, and other countries, but they are most often seen in the United States.
Related to tornadoes, waterspouts are weak twisters that form over warm water. They sometimes move inland and become tornadoes.
Dust devils are small, rapidly rotating columns of air that are made visible by the dust and dirt they pick up. Dust devils are not associated with thunderstorms. Either are fire tornadoes, which can spawn from wildfires.
What causes tornadoes?
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The most violent tornadoes come from supercells, large thunderstorms that have winds already in rotation. About one in a thousand storms becomes a supercell, and one in five or six supercells spawns off a tornado.
Tornadoes can occur at any time of year, but they are more common during a distinct season that begins in early spring for the states along the Gulf of Mexico. The season follows the jet stream—as it swings farther north, so does tornado activity. May generally has more tornadoes than any other month, but April's twisters are sometimes more violent. Farther north, tornadoes tend to be more common later in summer.
Although they can occur at any time of the day or night, most tornadoes form in the late afternoon. By this time the sun has heated the ground and the atmosphere enough to produce thunderstorms.
Tornadoes form when warm, humid air collides with cold, dry air.
The denser cold air is pushed over the warm air, usually producing thunderstorms. The warm air rises through the colder air, causing an updraft. The updraft will begin to rotate if winds vary sharply in speed or direction.