Read previewYou don't need to know a lot about tornadoes to understand the massive storms you'll see on screen in the new film "Twisters," debuting in US theaters Friday. 22 science terms to know before seeing 'Twisters'Cap: A layer of warm air thousands of feet high in the atmosphere that can slow or stop the formation of a thunderstorm. Sandwiched between warm, moist air and cold, dry air, the cap can also increase instability and cause a severe storm if it's removed. Eric Kurth/NOAADoppler radar: The National Weather Service's Doppler radars look like they have giant golf balls sitting on top of them. Recent research suggests severe storm activity is shifting to states like Alabama, Arkansas, Kentucky, Louisiana, Mississippi, and Tennessee.

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Persons: —, Eric Kurth, Ted Fujita, Paul Huffman, Sakuhei Fujiwhara, Matthew Cappucci, it's, Paul Markowski, Yvette Richardson, Joseph, Louis Lagrange, Sean Waugh Organizations: Service, Business, The Washington Post, NOAA, Tornadoes, NWS, FEMA, NASA, Federal Emergency Management Agency, National Aeronautics and Space Administration, Oceanic, Atmospheric Administration, National Weather Service, Library, Laboratory Locations: Elkhart , Indiana, Oklahoma, It's, Norman , Oklahoma, Kansas, Kansas , Nebraska , Oklahoma, Texas, Alabama , Arkansas , Kentucky, Louisiana , Mississippi, Tennessee