Identification of Mesovortexgenesis Mechanisms in QLCSs using PERiLS Radar Data

The Propagation, Evolution, and Rotation in Linear Storms field campaign is a unique project designed to take observations of Quasi-Linear Convective Systems (QLCSs) to better study their environmental and storm-scale processes, topics that have previously garnered limited attention in literature. QLCSs present several challenges to forecasters in the southeastern US including the tendency of such systems to develop in environments with large low-level vertical shear and minimal instability (high shear, low CAPE) as well as the ability of linear storms to produce intense rotation, termed mesovortices, at the leading edge of convection. Mesovortices are well-known to produce severe straight-line winds and weak tornadoes. There are several theories intended to explain mesovortexgenesis including the downward tilting of system generated gust front vorticity by downdrafts, horizontal shearing instability, and convergence and stretching of frictionally generated vorticity. However, there has yet to be agreement by the scientific community on which QLCS mesovortexgenesis mechanism is dominant.

This study incorporates quality controlled radar data from year 1 (March - April 2022) and raw data from year 2 (February - May 2023) of the PERiLS field campaign. Radars used include a mobile C-band as well as multiple mobile X-band radars. We will examine the velocity and reflectivity fields prior to and throughout the life cycle of QLCS mesovortices for each observed case using single and dual/multi-doppler syntheses, the latter of which will allow us to study the system’s 3-dimensional wind field. We hope these analyses will allow us to identify any common features that exist in the mesovortex development process.