Researchers prepare to launch an experimental weather balloon on April 5, 2022, near a storm in Greenville, Alabama. (NOAA)

This winter has brought multiple rounds of devastating severe weather to the southeastern U.S., with more than 200 reported tornadoes and 14 fatalities. To better understand the deadly storms in this region, scientists will conduct research as they travel through seven states in the second year of one of the largest and most comprehensive severe storm field projects to date.

Funded by the National Science Foundation (NSF) and NOAA, the PERiLS (Propagation, Evolution, and Rotation in Linear Storms) campaign will deploy dozens of instruments to measure the atmosphere near and inside storms. Researchers will focus on quasi-linear convective systems — commonly known as squall lines — that produce tornadoes. They will gather data from February 8-May 8 in predefined areas from the Missouri Bootheel southward to the Gulf Coast, and from the mid-and lower-Mississippi Valley eastward to the foothills of the Appalachian Mountains.

“The rapid evolution of storms in the southeast poses a unique challenge for researchers and forecasters,” said Karen Kosiba, NSF principal investigator and managing director of the University of Illinois Urbana-Champaign’s Flexible Array of Radars and Mesonets Facility offsite link. “PERiLS scientists hope to learn more about the complex ways in which these tornadoes form. If we can learn how, why, when and where they will form, then we can make better predictions, more precise and longer-lead time warnings and save lives.”

Storms in this region can pose a higher risk to people and property than in other parts of the country for two reasons. First, some storms and the tornadoes they produce can be challenging to predict in advance because they often develop and evolve rapidly. Second, the southeast U.S. tends to be more vulnerable because of unique scientific and socioeconomic factors, which previous research has shown include the frequency of nighttime tornadoes, larger population density relative to other tornado-prone areas in the U.S., and the larger amount and distribution of mobile and manufactured homes that pose added risks for residents when tornadoes strike.

The project involves the coordination of about 30 teams in the field using a variety of equipment including mobile radars, uncrewed aerial systems, trucks with instruments attached and different kinds of portable devices designed to measure lightning and the atmosphere within and around storms.

“We are collecting an unprecedented data set to better understand tornadic storms in the Southeast, the environments in which they form and the damage they leave behind,” said Anthony Lyza, PERiLS coordinating scientist and postdoctoral research associate with NOAA’s Cooperative Institute for Severe and High-Impact Weather Research and Operations (CIWRO) offsite linkat the University of Oklahoma.

The researchers will have additional help from about 55 NOAA National Weather Service (NWS) meteorologists who will join them in the field, gathering data ahead of storms and assisting with damage surveys after the storms. In addition, several NWS forecast offices will launch supplemental weather balloons as needed to support the project.

NWS forecasters in the region will have access to the experimental data collected by the scientists to use in real-time.

“Severe storms in the Southeast typically develop and change quickly,” said Brian Carcione, chief of the Science and Training Branch at NOAA’s NWS Southern Region Headquarters. “Access to additional radar and atmospheric data from the PERiLS campaign will be valuable to our forecasters when developing a forecast and issuing life-saving  warnings.”

PERiLS participants include:

• NSF

• NOAA

  • NSSL
  • Physical Sciences Laboratory
  • Global Systems Laboratory
  • NWS Southern Region

• Universities

  • University of Oklahoma (CIWRO)
  • University of Alabama, Huntsville
  • University of Louisiana, Monroe
  • Purdue
  • Texas Tech
  • Pennsylvania State University
  • SUNY Stony Brook
  • University of Illinois, Urbana-Champaign
  • North Carolina State