Tornadoes!

A tornado is a rapidly whirling, funnel-shaped cloud that reaches down from a storm cloud to touch Earth’s surface.

Animations http://www.suu.edu/faculty/colberg/Hazards/Hurricanes_Noreasters/Hurricanes_Anim_1.html http://www.classzone.com/books/earth_science/terc/content/visualizations/es2006/es2006page01.cfm?chapter_no=visualization

How tornadoes form. 1. there must be a high heat level and warm low pressure air rises up into a thundercloud (cumulonimbus) that has formed 2. Cold, dry (continental polar) air masses meet warm, humid (maritime tropical) air masses (usually from the Gulf of Mexico). 3. As the more dense cold air meets the less dense dry air, spiraling air forms the vortex of the tornado.

Tornado facts: most tornadoes form in our country more than any other in the world. “Tornado Alley” in the Great Plains area is where cold polar air from Canada meets warm Gulf of Mexico air. usually occur in spring and summer. only last about 15 minutes and only cover a few hundred meters high wind speeds- close to 480 kph

How tornadoes are measured. The Fujita Scale measures the strength and amount of damage of a tornado.(Fujita-Pearson Tornado Intensity Scale) http://news.bbc.co.uk/1/hi/world/5328524.stm http://profhorn.meteor.wisc.edu/wxwise/tornado/t.html

safety measures: Go to an area in a well-built building that is in the basement or a window-less room. If you are outside, find a low area. http://www.usatoday.com/weather/graphics/tornadoes/flash.htm

Review videos. http://weeklyreader.com/currentscienceanimations/twisted.html http://science.howstuffworks.com/tornado.htm/printable