Mechanisms Controlling the Probability of Tornadogenesis in Supercell Thunderstorms

North Carolina State University, Raleigh NC

Investigators

Abstract

The characteristics of supercell thunderstorms that form tornadoes are well-known. However, a large fraction of the supercells that exhibit those characteristics do not develop tornadoes. This research award will use high-resolution numerical modeling to investigate why tornadogenesis so frequently fails in environments that are otherwise favorable. The work has the potential to improve forecasting, nowcasting and warnings for tornadoes. The award will also contribute to training and mentoring of early-career research scientists, ensuring a diverse and highly capable workforce. The research team will conduct a numerical modeling study to analyze the within-storm attributes and associated environmental traits that distinguish simulated tornadic from non-tornadic supercells. The researchers suggest that more study needs to happen at the point at which tornadogenesis succeeds or fails, rather than focusing on the origin of the rotation. The Cloud Model 1 (CM1) model will be used in idealized simulation ensembles, multi-storm simulations, and toy model simulations to: 1) Explain why supercells with large surface vertical vorticity often fail to produce significant tornadoes, 2) Establish the environmental proxies that are most directly, physically linked to supercells with a high probability of tornadogenesis, and 3) Explain why multiple supercells within the same environment can differ dramatically in terms of tornado production. 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.