TornadoesLooking in wrong place when predicting tornadoes
Historically, there have been a wide number of conflicting theories about how tornadoes form, but the most widely accepted was that they form from the top down, based on work done from the 1970s through the 1990s. For the first time, new observational evidence shows that they actually form from the ground up, which could have a profound impact on the way tornado warnings are issued in the future. It’s the first time these hypotheses have been able to be evaluated observationally, thanks to a modern radar system that collects data very rapidly.
Weather forecasters may be looking in the wrong place when working to issue tornado warnings, new research led by Ohio University has demonstrated.
Historically, there have been a wide number of conflicting theories about how tornadoes form, but the most widely accepted was that they form from the top down, based on work done from the 1970s through the 1990s. For the first time, new observational evidence shows that they actually form from the ground up, which could have a profound impact on the way tornado warnings are issued in the future. It’s the first time these hypotheses have been able to be evaluated observationally, thanks to a modern radar system that collects data very rapidly.
“We need to reconsider the paradigms that we have to explain tornado formation, and we especially need to communicate this to forecasters who are trying to make and issue warnings,” said Dr. Jana Houser, assistant professor of meteorology at Ohio University and co-author of the new study. “Based on our results, it does not look like you are going to really ever be finding strong evidence of a tornado descending, so we need to stop making that a priority in our forecasting strategies.”
Ohio University says that a team led by Houser demonstrated that tornadoes actually form at the ground and move up rapidly, contrary to the long-held hypothesis that most tornadoes form at cloud level and descend to touch the earth. This evidence, the first of its kind, was gathered after Houser observed an EF5 tornado in May 2011; this work began during her doctoral work at the University of Oklahoma. Those findings were subsequently confirmed through observations from several other tornadoes, including a very compelling visual and radar analysis of the deadly El Reno tornado of May 2013.
“The coupled visual and near-surface radar observations from the El Reno 2013 case enable an analysis of the tornadogenesis process that has never before been obtained, providing a missing link in the story of tornado formation: the rotation associated with the tornado was clearly present at the surface first,” Houser said. She presented the findings to the American Geophysical Union at a conference Dec. 14.
