30 likes | 177 Views
Tornadoes. Tornadoes Rapidly whirling, funnel-shaped cloud that touches earth’s surface Winds speeds approach 500 km/h Formation From cumulonimbus clouds Warm moist air flows in at the bottom of a cumulonimbus cloud and moves upward. A low pressure system form inside the cloud
E N D
Tornadoes • Tornadoes • Rapidly whirling, funnel-shaped cloud that touches earth’s surface • Winds speeds approach 500 km/h • Formation • From cumulonimbus clouds • Warm moist air flows in at the bottom of a cumulonimbus cloud and moves upward. • A low pressure system form inside the cloud • The warm air begins to rotate as it meets winds blowing in different directions at different altitudes • A tornado forms as part of the cloud descends to earth in a funnel
Tornadoes • Most tornadoes occur in the United States. • Supercells - large thunderstorms that have winds already in rotation. • Most tornadoes in the United States occur in Tornado Alley • from Texas to Nebraska
Tornadoes • The average twister • about 660 feet (200 meters) wide • moves about 30 mph (50 kmh) • Meteorologists at the U.S. National Weather Service watch the skies for severe storms and tornadic activity with: • Doppler radar • Satellites • weather balloons • computer modeling • http://www.nationalgeographic.com/forcesofnature/interactive/index.html