Over the past few decades, America's tornadoes have been shifting east, a new study has found. Tornadoes have been shifting - decreasing in Oklahoma, Texas and Kansas but spinning up more in states along the Mississippi River and farther east, it revealed - and scientists aren't sure why. Tornado activity is increasing most in Mississippi, Arkansas, Tennessee, Louisiana, Alabama, Kentucky, Missouri, Illinois, Indiana, Wisconsin, Iowa and parts of Ohio and Michigan, according to a study in Wednesday's journal Climate and Atmospheric Science. Tornado Alley remains the top zone for tornadoes in the United States, but other areas, including the so-called Dixie Alley that includes much of the lower Mississippi Valley region, are catching up. Tornado activity is increasing most in Mississippi, Arkansas, Tennessee, Louisiana, Alabama, Kentucky, Missouri, Illinois, Indiana, Wisconsin, Iowa and parts of Ohio and Michigan, according to a study in Wednesday's journal Climate and Atmospheric Science.
Tornados are behaving strangely: The number of tornado outbreaks per year is fairly constant, but the number of tornados per outbreak has skyrocketed. In an effort to learn more, researchers looked at meteorological factors related to tornado outbreaks, and then dug into the data to see whether these factors had changed over time, said study lead researcher Michael Tippett, an associate professor of applied physics and applied mathematics at Columbia University. The analyses did yield a result, but an unexpected one, Tippett said. "The meteorological factors that are related with tornado outbreaks have also become more extreme," Tippett told Live Science in an email. "The surprising finding was that the change in meteorological factors did not have the expected signature of climate change."
Because tornadoes sometimes go undercounted, especially in the past and in less populous areas, scientists don't like to study trends by using counts of tornadoes. Gensini and tornado scientist Harold Brooks of the National Severe Storms Lab looked at "significant tornado parameters," a measurement of the key ingredients of tornado conditions. It looks at differences between wind speed and direction at different altitudes, how unstable the air is and humidity. The more of those three ingredients, the more likely tornadoes will form.
ST. LOUIS – A spring-like storm system spawned tornadoes that destroyed more than 100 homes and killed three people in the Central U.S. before it rumbled eastward Wednesday, putting about 95 million people in its path, forecasters said. The compact but strong storms, known as supercells, moved into the region on Tuesday and raked parts of Arkansas, Iowa, Indiana, Illinois, Michigan and Missouri before moving into Ohio, Kentucky, Tennessee and West Virginia. Forecasters with the Storm Prediction Center said the storm system appeared headed toward the mid-Atlantic states and southern New England, and that New York, Philadelphia, Baltimore, Atlanta and Washington, D.C. could be affected. The National Weather Service Storm Prediction Center in Norman, Oklahoma, received about two dozen reports of possible tornadoes late Tuesday and early Wednesday. Warning coordination meteorologist Patrick Marsh said crews are still determining if damage was from tornadoes or straight-line winds, and how many twisters touched down.