90 Using Overshooting Top Area to Discriminate Large, Intense Tornadoes

Tuesday, 23 October 2018
Stowe & Atrium rooms (Stoweflake Mountain Resort )
Geoffrey Marion, Univ. of Illinois at Urbana–Champaign, Urbana, IL; and R. J. Trapp and S. W. Nesbitt

Storm-top features such as convective overshoots have long been used to identify, via satellite data, storms capable of producing various convective hazards. In this study, we further explore the relationship proposed by Trapp et al. (2017, JAS) between overshooting top area (OTA) and the strength of near-ground rotation. Using a new set of idealized model simulations of supercells and QLCSs, and a new method for identifying convective overshoots with several advantages over currently-implemented algorithms, we find that OTA may serve as a discriminator of storms with the greatest potential to produce large, damaging tornadoes. We also find that the peak OTA tends to occur prior to the peak near-ground rotation. Application of this new method to GOES-16 data, and comparison of the OTA quantification to select tornado reports in 2017-2018, will be used to demonstrate the viability of this idea in real storms.
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