A new paper on the PERiLS (Propagation, Evolution, and Rotation in Linear Storms) project was selected by the American Meteorological Society and the editors of Bulletin of the American Meteorological Society (BAMS)  to be featured as a BAMS highlight. The paper discusses the design, execution and preliminary data of this groundbreaking collaboration project of  VORTEX-USA  and the U.S. National Science Foundation.

Quasi-linear convective systems (QLCSs) are responsible for approximately a quarter of all tornado events in the United States. PERiLS was the first field campaign in nearly 20 years focused specifically on collecting data to understand QLCS tornado formation and was the first large-scale effort  focused on cold-season QLCS tornadoes, which tend to be stronger and more prolific than their warm-season counterparts.

PERiLS participants were drawn from more than 10 universities, laboratories, and institutes, with over 100 students participating in field activities. Spanning two years (late winters and early springs of 2022 and 2023 to increase the probability of intercepting significant tornadic QLCS events) the field phases of PERiLS collected data in nine tornadic and non-tornadic QLCSs with unprecedented detail in a wide range of environments. 

“We collected 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. 

By learning how, when and where these types of tornadoes  form, forecasters can make better predictions and provide the public with more precise and longer-lead time warnings that save lives.

Storms in the Southeast U.S. 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.

PERiLS participants include:

• U.S. National Science Foundation
• NOAA
  • NSSL
  • Physical Sciences Laboratory
  • Global Systems Laboratory
  • NWS Southern Region
• Universities
  • University of Oklahoma (CIWRO)
  • University of Oklahoma
  • University of Alabama in Huntsville
  • University of Louisiana at Monroe
  • Purdue University
  • Texas Tech University
  • Pennsylvania State University
  • Stony Brook University
  • University of Illinois at Urbana-Champaign
  • North Carolina State University