Atmospheric science faculty members will participate in a national project this spring.
Three Texas Tech University researchers are hitting the road with their equipment this spring to learn more about how unique aspects of the southeastern United States environment affects the development, intensity and path of tornadoes.
Scheduled from March 1 to April 30, the Verification of the Origin of Rotation in Tornadoes EXperiment-Southeast (VORTEX-SE) is designed to study tornadoes in the southeastern United States as a follow-up to earlier projects VORTEX and VORTEX2, which focused on the Central and Southern Plains.
“There is reason to believe there are some unique features in this section of the country that contribute to tornado development,” said Chris Weiss, a Texas Tech associate professor of atmospheric science. “In response to some significant tornado events in the Southeast over recent years, particularly a large outbreak in April 2011, Congress mandated an investigation of tornadoes in this region, which Texas Tech is excited to be part of.
“Specifically, it is suggested that aspects of the environment – terrain, for instance – can influence the development, intensity and path of tornadoes. Also, a significant portion of the tornadoes in this region of the country develop from a specific type of storm complex named the quasi-linear convective system (QLCS), which often develops when instability is limited and vertical wind shear is strong. Just as with supercell thunderstorms, which are responsible for the majority of strong tornadoes nationwide, there is a lot to still learn about how QLCSs work.”
To study the storms, Texas Tech researchers are bringing along three observational platforms:
- StickNet probes: 24 instrumented weather stations, 16 of which will be part of a static network to measure temperature, humidity and wind in the northern Alabama and southern Tennessee environment. The remaining eight will be deployed immediately in the path of potential tornado-producing storms to sample storm-scale details.
- West Texas Lightning Mapping Array stations: Three portable stations, which will yield information on the electrical properties of storms.
- Balloon vehicle: It will launch balloons with an instrumented package attached into the environment surrounding severe thunderstorms to better understand how the vertical profiles of temperature, humidity and wind vary.
A primary goal of the project is to identify and sample environmental features that serve as a precursor for tornadoes, some of which may be tied to the local terrain and land use. Another objective is to assess how downdrafts from thunderstorms in the Southeast compare with storms elsewhere.
“I expect that the research carried out in VORTEX-SE will have an impact on our overall understanding of tornado-producing storms in West Texas,” Weiss said. “One area of crossover I see relates to the false alarm rate for tornadoes. We believe that the thermodynamic signature of thunderstorm downdraft regions has a bearing on the tornado potential. With knowledge of the negative buoyancy associated with these downdrafts, it may be possible to issue more accurate tornado warnings.”
The Texas Tech researchers involved are Weiss, who specializes in severe storm dynamics and tornadogenesis; Eric Bruning, an associate professor of atmospheric sciences who specializes in storm electrification; and Johannes Dahl, an assistant professor of atmospheric science who specializes in convective storm dynamics and supercells and tornadoes. The project is sponsored by the National Oceanic and Atmospheric Administration and organized by the National Severe Storms Laboratory.