During my time with the group, I was the primary driver for a mesonet vehicle, M3. I was joined by Ed Grubb, Matt Grzych, and Paul Samaras.
From 2009-2011, TWISTEX was featured on Discovery Channel’s hit TV series, “Storm Chasers”. We were also featured on multiple other TV specials across multiple networks.
NOTE (MARCH 2025): This section is currently under construction with new content to come! Check back often!
The project normally ran from mid-April through the end of June with a domain that covers the Great Plains and portions of the Midwestern United States. The project was normally at full strength for most of May and June with four vehicles, all equipped with roof-mounted mobile mesonet weather stations. One of the vehicles transported an array of in situ thermodynamic and video probes. Due to graduate and upper-division undergraduate student participant availability, a reduced vehicle compliment consisting of the in-situ probe deployment truck and one support mesonet station vehicle was used in the first few weeks of the project and in any spot chasing through the summer and early fall.
The research objectives were to better understand tornado generation, maintenance and decay processes and to gain insight and knowledge of the seldom sampled near-surface internal tornado environment. Progress on these research fronts was aimed toward increasing tornado warning lead time, while the internal tornado near-surface sampling provided essential ground truth data for structural engineering analysis of the interaction of tornadic winds with homes and buildings.
TWISTEX was one of the featured teams in seasons 3, 4 and 5 of Storm Chasers on the Discovery Channel. The group was also featured on National Geographic Channel’s “Disaster Labs” as well as the subject of several other major TV specials.
TWISTEX 2010: An Overview
For 2010, we will be engaging in field research to collect data of the following:
~ Tornadoes and tornado proximity environments
~ Boundaries associated with supercells
~ Study hail 2″ and larger (Measure impact velocity, magnitude, and provide ’soft-catch’ for later analysis)
The objectives of this research are to better understand tornadogenesis, maintenance and decay processes and to gain insight and knowledge of the seldom sampled near-surface internal tornado environment. Progress on these research fronts is aimed toward increasing tornado warning lead time while the internal tornado near-surface sampling provides essential ground truth data for structural engineering analysis of the interaction of tornadic winds with homes and buildings.
Tornadoes and Tornado Proximity Environments:
Tornado Core Sampling
Several hardened instruments will be deployed in paths of tornadoes to collect the following datasets:
* Pressure
* Temperature
* Humidity
* Wind speed/direction
* Visualization for accurate debris/hydrometeor velocities and for verification of the tornado-relative location of the in situ sampling
The thermodynamic probes are called Hardened In-situ Tornado Pressure Recorders (HITPR). All of the hardened instrumentation can collect/store the datasets. Measurements are recorded at 10 samples/second, and stored on non-volatile flash cards.
HITPR and video probe:
TWISTEX will also have video probes that will provide visualization using 7 cameras each for a total of 14 cameras being deployed into the tornado core. Collectively the two camera probes will be used for photogrammetry purposes to visualize/measure tornado-driven debris and hydrometeors as well as for determining the tornado-relative location of the HITPRs.
New additional technologies will be used by deployment crew members to collect photogrammetric data from tornadoes as close as possible. One technique will be to record close tornado imagery using two digitally synchronized high-resolution high-speed cameras running at 500 frames per second for stereo photogrammetry techniques. This technique will provide excellent time resolution for velocity determination of low-level tornado core winds and lofted debris.
Beginning this season, TWISTEX will be deploying a newly developed instrument into tornado cores. The new instrument will be collecting wind data using different methodologies of anemometry at three different heights up to and including 2 meters AGL. Instrument will also have 6-9 video cameras along with a prototype flow visualization technique.
Samaras will coordinating the in-situ tornado core measurements, as well as the overall TWISTEX mission.
While there are abundant kinematic datasets gathered by mobile radar of the tornadic region of supercells, the number of quality mobile mesonet or sticknet thermodynamic datasets of the flow field proximate to the tornadic region, generally within the supercell rear-flank downdraft (RFD) outflow, are comparatively rare. Even rarer are mesonet datasets reaching within about 1.5 km of tornadoes and datasets sampling the thermodynamic evolution of the RFD outflow. Each of the participating TWISTEX vehicles will have a mobile mesonet (MM) station mounted on the roof including the probe deployment truck. The mobile mesonet will be attempting to gather near-surface thermodynamic and kinematic data in as many quadrants of the RFD as possible. When coupled with the in-situ probe array data which represents another effective mesonet station, it is hoped to obtain thermodynamic and kinematic mapping that will describe characteristics of the flow reaching the tornado. Even if the hardened tornado probes do not take a direct hit, a peripheral tornado sampling is still very worthwhile. Drs. Lee and Finley will be directing the mobile mesonet operations.
Tim Samaras, TWISTEX Director
Paul Samaras, Videographer
Carl Young, Videographer
Dr. Bruce Lee, Mesonet Director
Dr. Cathy Finley, Mesonet Co-Director
Tony Laubach, Mesonet Team Leader
Ed Grubb, Mesonet Navigator, Mechanics
Matt Grzych, Software & Systems Dev.
Chris Karstens, Software Development
Ben McMillan, Team Medic
* Rotation of Iowa State Students
Participants of the TWISTEX research project have contributed to many publications.
Carl Young
Tim Samaras
Paul Samaras
