CU-Boulder Faculty, Students to Participate in National Study on Tornado Formation

Published: April 13, 2009

University of Colorado at Boulder faculty and students will participate in a nationwide project exploring the origins, structure and evolution of tornadoes by probing both the early and late stages of severe storms over the central Great Plains this spring.

The collaborative Verification of the Origins of Rotation in Tornadoes Experiment 2, or VORTEX2, will be conducted from May 10 through June 13. The project is the largest and most ambitious attempt to study tornadoes in history and will involve more than 50 scientists and 40 research vehicles, including 10 mobile radar instruments.

CU-Boulder's College of Engineering and Applied Science will be flying an Unmanned Aerial Vehicle, or UAV, that weighs 12 pounds and has a 10-and-a-half-foot wingspan. The aircraft will be deployed and operated by CU's Research and Engineering Center for Unmanned Vehicles and will make one-hour flights into developing storms to measure air pressure, temperature, relative humidity and wind velocities.

Led by aerospace engineering sciences Professor Brian Argrow, the CU team hopes to fly the aircraft at least three times during the six-week field experiment. The team also includes CU-Boulder Assistant Professor Eric Frew, Research Assistant Thomas Aune and doctoral students Jack Elston and Cory Dixon. The effort also includes collaborators from the University of Nebraska at Lincoln, the University of Oklahoma and Rasmussen Systems of Grand Junction, Colo.

"Our team worked for years to develop the capability to operate unmanned aircraft for such challenging applications in order to extend our reach to places too dangerous for human presence," said Argrow.

The second CU-Boulder experiment involves a laser disdrometer, an instrument that can measure raindrop and hail-size distribution and falling velocity in severe storms. Weighing about 5 pounds, the 2-foot-long instrument features a horizontal laser beam through which precipitation particles pass, said project leader and Assistant Professor Katja Friedrich of the atmospheric and oceanic sciences department.

Friedrich and CU-Boulder doctoral student Rachel Humphrey hope to deploy several disdrometers on the leading edge of severe storms, mounting them on fixed platforms or on mobile, storm-chasing trucks. The instrument also will measure temperature, humidity, pressure and wind velocity.

"A better understanding of severe storm behavior can ultimately lead to better warnings that can save lives and protect property," said Friedrich. "In addition, VORTEX2 will enable graduate students the opportunity to participate in data collection efforts as part of a major field campaign."

The VORTEX2 researchers will sample "supercell" thunderstorms -- violent storms capable of producing damaging winds, large hail and tornadoes. Areas of focus include southern South Dakota, western Iowa, eastern Colorado, Nebraska, Kansas, the Texas Panhandle and western Oklahoma. The operations center will be at the National Weather Center in Norman, Okla.

The CU-Boulder experiments are funded by the Atmospheric Sciences Division of the National Science Foundation. VORTEX2 is a $10.5 million program funded by the National Oceanic and Atmospheric Administration, NSF, 10 universities and three nonprofit organizations.

"Data collected from VORTEX2 will help researchers understand how tornadoes form and how the large-scale environment of thunderstorms is related to tornado formation," said Louis Wicker, a research meteorologist with NOAA's National Severe Storms Laboratory and co-principal investigator on the project.

The original VORTEX program operated in the central Great Plains during 1994 and 1995 and documented the entire life cycle of a tornado for the first time in history. VORTEX2 will build on progress made during VORTEX to further improve tornado warnings and short-term severe weather forecasts.

Scientists and students throughout the United States, Canada and Australia will be working with the Center for Severe Weather Research in Boulder, Rasmussen Systems, the NOAA National Severe Storms Laboratory, the OU/NOAA Cooperative Institute for Mesoscale Meteorological Studies in Norman, Okla., and the National Center for Atmospheric Research in Boulder.

Other collaborators include Penn State University, the University of Oklahoma, Texas Tech University, Lyndon State College, Purdue University, North Carolina State University, the University of Illinois, the University of Massachusetts, the University of Nebraska, Environment Canada and the Australian Bureau of Meteorology.

To learn more about the experiment visit the VORTEX2 site at and the official project Web site at