Collaborative Research: Polarimetric Radar and Modeling Perspectives of Updraft, Cold Pool, and Mesovortex Evolution in Quasi-Linear Convective Systems

Lines of thunderstorms, known in the meteorological community as Quasi-Linear Convective Systems (QLCSs), can be responsible for high-impact weather such as tornadoes and extreme straight-line winds. Numerical weather models have improved their ability over the years to forecast thunderstorms, but they still struggle with the timing of when thunderstorms grow into larger systems and whether these systems will produce tornadoes or extreme winds.

In this project, the research team will create a climatology of QLCS events over the past 10+ years, including advanced weather radar information about drop sizes and shapes, that will be used alongside idealized numerical modeling to answer questions about the structure and impacts of QLCSs. The primary societal impact from the research will be improved understanding, and potentially forecasting, of a significant weather hazard that affects lives and property.

The research team will also train and educate a number of students and provide outreach and educational materials to a variety of groups.

This award intends to make transformative gains in the understanding of QLCS structure, responses to environment, radar signatures, and hazards. The research team will create a new database of QLCS events covering the period after the dual-polarization upgrade of the US national weather radar network. Using a combination of Machine Learning techniques and existing software, QLCS events will be classified, their environments will be described, and polarimetric variables will be determined.

The database will be analyzed and then combined with idealized numerical simulations from Cloud Model 1 to address the hypotheses that mesovortices will be more numerous and longer-lived in high-shear environmental clusters, and that QLCS updrafts will be deeper and more intense when the QLCS environment promotes more intense cold pools via greater evaporative cooling of precipitation.

This project is jointly funded by the Atmosphere Cluster in the Division of Atmospheric and Geospace Sciences and the Established Program to Stimulate Competitive Research (EPSCoR).

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.