Newswise — As some of the nation’s top tornado scientists converge on northern Alabama and the Tennessee Valley this week to kick off a congressionally mandated project to study how and why tornadoes form, researchers from Texas Tech University’s National Wind Institute have already been there for a week.
Associate professors Chris Weiss and Eric Bruning and graduate research assistants Aaron Hill and Vanna Chmielewski – all from the atmospheric science group within the Department of Geosciences – arrived in Alabama early last week to deploy equipment for the second year of the Verification of the Origins of Rotation in Tornadoes Experiment-Southeast (VORTEX-SE), which will run from Wednesday (March 8) through May 8. Team members are now stationed in Huntsville to await signs of potentially dangerous storms.
Their equipment includes lightning mapping array sensors that will be deployed ahead of storms to map characteristics of lightning strikes, including size and channel length; dozens of weather balloons to measure changes in temperature, wind and moisture content at different heights; and 24 StickNet platforms that measure temperature, pressure, humidity and wind to understand how atmospheric states change around developing tornadoes. Sixteen StickNets are already in place to gather long-range data while the other eight will be deployed directly in the path of oncoming storms.
“We’re going to get out ahead of target storms of interest, deploy these probes and try to get out of the way before the storm moves over top of them,” Weiss said. “It’s rather harrowing.”
But the rewards may be worth the risk. VORTEX-SE is organized through the National Severe Storms Laboratory, a branch of the National Oceanic and Atmospheric Administration (NOAA). Collaborators within NOAA are using observations collected in real time from the StickNets to update their hourly predictions. Done for the first time last year, this method actually improved the accuracy of forecasts and predicted a storm that otherwise would have been missed.
“That tells us we’re actually getting something meaningful about the predictability of these phenomena,” Weiss said. “The predictability is pretty poor on this stuff; that’s why we’re doing this.”
The project began in the wake of the April 27, 2011, tornado outbreak that killed more than 200 people in Alabama alone.
“Congress decided we needed to pay some specific attention to the southeastern tornado problem, specifically what features are unique to the Southeast that influence tornadoes,” Weiss said. “Most of our previous projects, including VORTEX and VORTEX-2, were centered out in the Plains, where we see the peak of climatology for tornadoes. VORTEX-SE is a follow-up from VORTEX-2. We’re going to try to apply some of the things we learned about what influences tornado development directly to the Southeast.”
There are many obstacles to tornado prediction in the Southeast, only one of which is the fact that most prior tornado research has been conducted in the High Plains, a geographic region typically known as “Tornado Alley.”
“We’re going to try to learn some new things about the southeastern environment, for example, the role of terrain in the development of tornadoes,” Weiss said. “We’re going to try to understand the types of storms that produce tornadoes out here. In the Plains, we’re well acquainted with the supercell thunderstorm, which is the parent thunderstorm of most of the large tornadoes we see. In the southeastern United States, we do have some of those supercell thunderstorms, but most of the tornadoes actually come from other types of storms; we call them quasi-linear convective systems. They have a very low degree of predictability, they tend not to produce as strong of tornadoes, but the tornadoes they do produce have less lead time in terms of warning. So we’re trying to understand this specific breed of thunderstorm better.”
In many ways, it can be more dangerous to conduct tornado research in the Southeast than on the Plains.
“A supercell usually moves 20 to 30 miles per hour on the Plains, but in the Southeast, storms move a lot faster, and a lot happen at night,” Weiss said. “On top of that, the visibility is low because of all the hills and trees. So I have to really think about it: is it safe? Are we going to get something useful? I’m calibrated for the Plains, because I’ve been doing it here for over 20 years. This really changes the equation and I have to think through each decision a lot more because no one’s really done this before.”
Hill said those involved in the project hope to gain some wider knowledge through its specific lens.
“We’d like to learn more about tornadoes in general,” Hill said. “Yes, we’re focusing on a different area of the country, the differences between tornadic storms in the Southeast and those in the Plains, but more fundamentally, how do tornadoes really form, what are the underlying mechanisms that lead them to form and how do those differ from storms that don’t produce them? That’s what we’re studying.”
Texas Tech’s researchers will be joined in the project by teams from Purdue University, University of Alabama-Huntsville, University of Oklahoma, North Carolina State and University of Louisiana-Monroe.
“We’re really excited to be part of this project,” Weiss said. “Texas Tech is one of a number of universities participating, but in terms of the outlay of field instrumentation, Texas Tech has probably the most platforms out there. It’s great to have the opportunity to use the assets we’ve built here at Texas Tech specifically for this research problem but we also have the opportunity to collaborate with other institutions and federal labs to try to better understand the southeastern tornado problem.”
One of the benefits of Texas Tech’s participation in the project is the national visibility it will gain.
“Not only are we accomplishing something scientifically, but we’re bringing a lot of exposure to the university,” Weiss said. “That has feedback on recruitment, not just for students but also for faculty. They see we have a good research enterprise here at Texas Tech, and these types of projects really put Texas Tech on the map.”
About the National Wind InstituteTexas Tech’s National Wind Institute leads the nation in wind research. The department was created after an F5 tornado killed 26 people and destroyed portions of downtown Lubbock, Texas, on May 11, 1970. Faculty representing the university’s civil engineering department and atmospheric sciences group collaborated on solutions for what could be done to minimize the effects of severe wind events such as tornadoes and hurricanes on lives and structures.
Through NWI, scientists and engineers have collected one of the country’s largest repositories of wind data and helped develop the Enhanced Fujita Scale, implemented in 2007 by the National Weather Service.
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CONTACT: Chris Weiss, associate professor of atmospheric science, Department of Geosciences, Texas Tech University, [email protected]
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