A team of nine scientists embarked on a daring mission to study a destructive tornado that tore through southern Iowa at a high speed of nearly 45 mph. The tornado, rated an EF4 by the National Weather Service, left a trail of devastation in its wake, overturning cars, flattening homes, and claiming the lives of five people on May 21. This event marked one of the deadliest tornadoes recorded this year, with 35 individuals injured.

While most people sought shelter in basements, the team of scientists, known as storm chasers, seized the opportunity to gather crucial data on the twisters. They swiftly deployed their radar trucks and scientific instruments, positioning themselves just 10 miles west of the town of Greenfield, where the tornado had struck. Facing challenging circumstances with debris falling around them, the researchers braced themselves to collect valuable information.

This ambitious "intercept," as they call it, allowed the team to measure wind speeds reaching over 300 mph within the tornado, from multiple angles. This data provides a rare and detailed insight into the inner dynamics of such a powerful vortex, shedding light on how wind speeds in the air correspond to ground damage and the factors that can intensify or weaken tornadoes.

Tony Lyza, a physical scientist at the National Severe Storms Laboratory, praised the study, emphasizing the rarity of tornadoes producing such intensity and damage in the United States. He remarked that the researchers' ability to observe and document the twister while it was at its most severe peak estimated damage was of great significance.

Tornado science remains a complex and unsettled field, primarily due to the challenge of obtaining high-quality data. However, these recent findings could potentially unravel essential questions about tornado formation, structure, and the factors that contribute to their intensity or breakdown. By untangling these uncertainties, scientists aim to develop improved tornado prediction systems and assist in the construction of more resilient structures.

Led by University of Illinois researchers Joshua Wurman and Karen Kosiba, the team was supported by the University of Illinois Flexible Array of Radars and Mesonets (FARM) team, partially funded by the National Science Foundation. The researchers started their day in McCook, Nebraska, after a night of storm-chasing in Colorado. Their journey led them to Greenfield, approximately a six-hour drive away.

Chasing tornadoes is not without risks, as demonstrated by the tragic deaths of three tornado chasers in 2013. The FARM researchers faced rapidly moving storms, requiring them to quickly reposition their equipment to capture the best measurements from a safe distance.

The team's efforts were not in vain, as they succeeded in capturing detailed radar data during the intense 45-minute tornado in Greenfield. Winds of approximately 80 mph battered their radar truck, but the scientists remained focused on their screens, analyzing the information streaming in. Their radar beams provided precise measurements of raindrops, debris, and the tornado's destructive path.

As the tornado ravaged Greenfield, displaying multiple swirling vortices at times, the scientists reached wind speeds of over 300 mph for a fraction of a second. This violent event caught the attention of Tim Marshall, a veteran storm chaser based in Texas, who highlighted the significance of the findings.

Despite the tornado's narrowing width when it struck Greenfield, the reasons behind this change remain elusive. The detailed radar data collected by the scientists offers a promising avenue for unraveling this and other mysteries surrounding tornado formation.

Joshua Wurman acknowledged that there is still much to learn from this valuable data, stating that it would be discussed and studied for years to come. The information gathered by the team has the potential to advance tornado science, providing a deeper understanding of these natural disasters and their impact.

Karen Kosiba plans to correlate the wind speed data with ground damage surveys and model the thermodynamics of the event, which could provide insights into the factors that contribute to intense wind speeds. This research could ultimately contribute to the development of more accurate tornado prediction systems and the construction of stronger and more resilient structures.

Storm chasing remains a dangerous pursuit, but for these scientists, the pursuit of knowledge is worth the risks. The destructive power of tornadoes serves as Mother Nature's fingerprint, guiding scientists in evaluating and understanding these catastrophic events.