The PERiLS Project: Tornado Chasing in the Southeast

The PERiLS (Propagation, Evolution and Rotation in Linear Storms) project is designed to study tornadoes produced by Quasi-Linear Convective Systems (QLCS) in the southeast United States. QLCS-spawned tornadoes pose a significant threat to lives and property, but forecasting QLCS tornado events poses special challenges, more so than forecasting supercell tornadoes. PERiLS is the largest and most ambitious field project focusing on QLCSs tornadoes, combining a dense, adaptable X- and C-band research radar array, including substantial instrumentation from the Flexible Array of Radars and Mesonets (FARM) including the new quickly-assembled C-band On Wheels (COW), two Doppler On Wheels (DOW) a multitude of quickly-deployable surface instruments (PODNET), the UI deployable wind profiler, Mobile Mesonets, and several upper air sounding systems, to provide the sampling necessary to address environmental factors and storm processes that lead to QLCS tornadogenesis. PERiLS was a multi-year field project; the first field phase occurred from 1 March to 1 May 2022; and the second field phase from 8 February to 8 May 2023.

Preliminary data and analyses that address the science objectives of the National Science Foundation research teams, the pre-scouting and design of a radar network for each IOP, and other unique experimental field project design will be discussed. PERiLS conducted four IOPs during the 2022 field phase and five IOPs during the 2023 field phase. Tornado strength circulations were observed during many of the IOPs, but the strongest tornadoes were associated with supercells ahead of the QLCSs. An overview of the radar data collected as well as preliminary analyses of IOPs 1 and 3 from Years 1 and 2 and will be presented.