The destructive energy of a tornado is generated by the clash of volatile, lightning storms and “soupy” moisture from the Mexican Gulf.  Then, it’s topped off by funneling warm air. That’s Josh Wurman’s explanation of how the swirling devastation is formed on the Great Plains.  He said there are more than 1,000 disruptions across the United States in a single year, and most are seen in the spring months. Wurman revealed these and other facts to attendees following the IMAX film premier of “Tornado Alley” at Reuben H. Fleet’s Science Center in Balboa Park on March 15. Narrated by Bill Paxton, the film follows “Storm Chasers” star Sean Casey and the scientists of VORTEX2, the largest tornado-research project ever assembled.  Wurman, a storm researcher and president of the Center for Severe Weather Research, stars in the film along with colleagues Karen Kosiba and Don Burgess. The documentary features a mobile armada that penetrates a tornado’s inner workings in an attempt to dissect information that will benefit many.  Recently, the Downtown News caught up with the meteorologist/scientist from Boulder, Colo., to discuss his role with the research team. “Thunderstorms develop in warm, moist air in advance of eastward-moving cold fronts,” he explained. “These thunderstorms often produce large hail and strong winds. Tornadoes in the winter and early spring are often associated with frontal systems that form in the central states and move east.    “Statistically, each decade has more tornadoes recorded because there are more technological means to communicate, not because there are more [tornadoes]. Now, local farmers have video cameras and e-mail it to the nearest TV station. If a tornado happened in west Kansas in 1920, few would have seen it and there was less chance of warning.”   Wurman explained that, with current technology, people have at least 13 minutes to take cover from an impending tornado, but researchers would like to improve the alarm system to 20 minutes. Some of the difficulty in creating an effective alarm system comes from the fact that most tornadoes occur in sparsely populated areas, mostly in open regions of Oklahoma, Kansas and Nebraska. It is that fact, however, that has saved us from what would otherwise be more devastation and destruction.    “It’s rare that you get one as intense as 150 mph through populated areas,” he said. “Although tornadoes occur in many parts of the world, the most destructive forces of nature are found along the front range of the Rocky Mountains, in the Texas panhandle, and in the southern High Plains.” The most intense tornado Wurman and his team have encountered measured 301 mph in Bridge Creek, Okla., on May 3, 1999. It was the highest on record and killed about three dozen people.  “[On average] tornadoes we’ve researched are about 200 to 300 yards across,” he said. “Larger cores can be a mile wide and 50 miles long. ”    Asked about waterspouts along the West Coast, he said they don’t have all the ingredients to develop into a tornado inland, “but I never like to say never.” For more information on “Tornado Alley” or for movie times, visit www.rhfleet.org or call (619) 238-1233.