Meteorologist Thea Sandmael was on a mission to track down a specific type of tornado known as a squall line tornado. Unlike the more common supercell tornadoes, squall line tornadoes develop along long rows of storms known as quasi-linear convective systems. These tornadoes are generally less intense but can still be dangerous, especially because they are difficult to detect and anticipate.
Sandmael and her team evacuated their post as they watched the tornado approach, highlighting the unpredictable nature of these twisters. Squall line tornadoes are more likely to occur in the southeastern United States, which is already a vulnerable region for tornadoes due to its dense population and high concentration of mobile homes.
Researchers like Karen Kosiba and Thea Sandmael have been working on the PERiLS field campaign to gather more data on squall line tornadoes. Their research has revealed that these tornadoes may be more common and dangerous than previously thought. Squall line tornadoes have been found to form in environments with low convective available potential energy (CAPE) values, suggesting that these twisters can develop in unexpected conditions.
In addition to being more common, squall line tornadoes can also be more complex. Recent observations have shown that these tornadoes can contain multiple vortices, creating subvortices that can increase the intensity of the tornado. These subvortices can be short-lived and difficult to detect, making them a challenge for forecasters.
Researchers like Todd Murphy have been using lidar instruments to monitor changes in the atmosphere before a squall line arrives. They have found that key ingredients for tornado formation, such as wind shear and rotation, can change rapidly before a squall line produces tornadoes. By monitoring these changes, meteorologists may be able to issue warnings more effectively and improve tornado forecasts.
Overall, the research on squall line tornadoes is ongoing, and scientists are continuing to analyze the data collected during campaigns like PERiLS. The goal is to improve our understanding of these tornadoes and develop better forecasting techniques to keep communities safe from these dangerous and unpredictable storms.
