main idea; Tornadoes have the strongest winds of any kind of weather. They can flip trains upside down. They can tear the roofs off of buildings. They can also pull huge trees out of the ground. Tornadoes are thin columns. They are strong, spinning air. They can form during thunderstorms. They go from the bottom of the storm all the way down to the ground. Tornadoes usually form out of very large thunderstorms. These storms are called supercells. Most tornadoes are less than 1/4 of a mile wide. They are rarely on the ground for more than half an hour. However, their winds can spin at 250 miles per hour or more. They can cause terrible damage. Tornadoes can happen almost anywhere on earth. However, more form in the United States than in any other place. They are most common in the flat area in the middle of the United States. This area has been given the nickname of Tornado Alley. Cool, dry air comes from Canada. Then it meets warm, moist air from the Gulf of Mexico. Warm, dry air also blows in from the Southwest. Each year, as many as 1,200 tornadoes form in the United States. Dary of Wimpy Kid DAYS Other countries get tornadoes, too. However, they happen much less than in the United States. Canada is second. It has about 120 tornadoes each year. England is third and has about 34 tornadoes each year. New Zealand and Japan are fourth and fifth. They each get about 20 per year. Most people hope to never see a tornado. However, some people try to get close to them. They try study them. These people are known as storm chasers. They wait for the right weather to form. Then they take special tools in their trucks. They take pictures and record information with special computers and machines. Their work helps weather scientists learn more. What they learn helps keep people safe from the earth's strongest weather. Jennife​