Understanding supercell dynamics via a novel "ensemble of ensembles"

Funding source: National Science Foundation

Duration: 2026-2029

Supercells (long-lived rotating thunderstorms) have great impact on our society, accounting for most significant tornadoes and very large hail (in addition to producing intense rainfall and damaging winds). Completed and ongoing work by our group has established connections between supercell structures (particularly low-level mesocyclones) and their environments, and further linked these structures to the likelihood of tornadoes.  Our community has often distilled such linkages into relatively limiting, one-to-one relationships.  To advance our understanding (and thus improve forecasts and warnings), we must grapple with the stochastic nature of supercells by representing the within-storm and between-storm variability of supercell behaviors across the full parameter space.  This project continues our hypothesis-driven research on fundamental supercell processes by exploiting an “ensemble of ensembles”, a large population of high-resolution supercell simulations created during recent studies.  The goal of this project is to explain the volatility in tornado and hail production linked to variations in storm motion and storm structure.  To accomplish this goal, we will pursue three specific objectives: 1) explain the variability in supercell storm motion and how it modulates tornado probability across a large number of simulations; 2) explain the variability in supercell vertical structure and how it modulates tornado probability across a large number of simulations; and, 3) explain the variability in supercell hail production across a large number of simulations.