RAPID: Preliminary Scientific Assessment of the Monroe, Louisiana Tornado on 12 April 2020

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On April 12th, 2020, a strong tornado impacted Monroe, Louisiana and produced significant damage. The tornado moved within very close range of instrumentation operated by the University of Louisiana at Monroe (ULM), including a weather radar and other instruments that provide measurements of wind and temperature at the surface and aloft. This award will allow the investigator team to perform an enhanced damage survey and initial scientific analysis of the unique storm system that produced the tornado. The broader societal impact of the project is through the identification of the factors that led to this strong tornado, in order to provide better forecasts of severe weather in the future. Several students will be involved in the analysis, ensuring the development of the next generation of scientists.The Monroe tornado of Easter Sunday 2020 moved within 1 km of the S-band, dual-polarimetric radar operated by ULM. Additionally, measurements from a Doppler wind lidar, microwave radiometer, and multiple surface stations were collected. The tornado was embedded in a Quasi-Linear Convective System (QLCS), which traditionally produce mostly weak tornadoes. However, the Monroe tornado was a strong EF-3 tornado, leading to question about how it reached that intensity. Several hypotheses related to Quasi-Linear Convective System (QLCS) tornadogenesis will be addressed using the measurements from this tornado: 1) A surging baroclinic boundary enhances the near-storm QLCS environment, making it more conducive to tornadogenesis by locally increasing low-level (i) wind shear, (ii) instability, and (iii) convergence, 2) A relatively warmer QLCS outflow promotes stretching of surface vorticity, and 3) Observable radar reflectivity structures, such as bowing segments, can be linked the success or failure of QLCS tornadogenesis.Additionally, given the close approach of the tornado to the ULM radar, links between the radar data and damage path can be made, improving our understanding of how remotely sensed radar data correlates to tornadoes in real-time. The project will collect aerial imagery from UASs to address this issue.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.