Thunderstorms, Tornadoes, and Hurricanes Different names for Hurricanes Hurricane – Atlantic Ocean and eastern Pacific Ocean Typhoon – Western Pacific Ocean Cyclone – Indian Ocean or off the coast of Australia Where is it likely to form? Tornado – Tornadoes often form in “Tornado Alley,” an area of the Central Plains between the Rocky Mountains and the Mississippi River. Hurricane – A hurricane forms over warm waters, including the Pacific Ocean, Atlantic Ocean, and Indian Ocean. What causes it to form? Tornado – One way a tornado forms is when moist, warm air meets cool, dry air head on. Hurricane – A hurricane forms when warm, moist air rises over tropical waters and wind speeds reach beyond 118 kph (73 mph). How big is it? Tornado – The diameter is usually between 100 and 600 m; some are a few meters wide; others are more than 1600 m (1 mile) wide. Hurricane – It is usually 550km (342 miles) in diameter. How fast does it move? Tornado – Some stand nearly still; others move faster than 100 kph (62 mph) Hurricane – A hurricane can move at speeds of 8 to 24 kph (5 to 15 mph). How fast do its winds rotate? Tornado – Its winds can move up to 350 kph (217 mph). Hurricane – A hurricane’s wind speeds can range from 119 to 250 kph (74 to 155 mph) or more. With what scale can you measure its damage? Tornado – The Fujita Scale Hurricane – The Saffir/Simpson Hurricane Scale