The Propagation, Evolution, and Rotation in Linear Storms (PERiLS) Project

Quasi-linear convective systems (QLCSs) are responsible for approximately a quarter of all tornado events in the United States, but no field campaigns have focused specifically on collecting data to understand QLCS tornadogenesis. The Propagation, Evolution, and Rotation in Linear Storms (PERiLS) project was the first observational study of tornadoes associated with QLCSs ever undertaken. Participants were drawn from more than 10 universities, laboratories, and institutes, with over 100 students participating in field activities. The PERiLS field phases spanned 2 years, late winters and early springs of 2022 and 2023, to increase the probability of intercepting significant tornadic QLCS events in a range of large-scale and local environments. The field phases of PERiLS collected data in nine tornadic and nontornadic QLCSs with unprecedented detail and diversity of measurements. The design and execution of the PERiLS field phase and preliminary data and ongoing analyses are shown. KEYWORDS: Severe storms; Squall lines; Tornadoes; Mesoscale processes; Storm environments; Mesoscale forecasting
1. Introduction Over the past 10 years, ~1400 tornadoes occurred annually in the United States, of which roughly 15%-25% are spawned by quasi-linear convective systems (QLCSs) (e.g., Trapp et al. [...]