Analyzing Supercell Intensity Changes in a Heterogeneous Environment in the VORTEX2 Supercell Pair in Southeastern Colorado on 11 June 2009

Much of what we understand about supercell thunderstorms comes from idealized simulations containing homogeneous environments. However, determining how a supercell will respond to changes in their environment, such as heterogeneity due to boundaries, the transition from day to night, or interactions with other storms, is much more challenging. Our current understanding of how supercells evolve given those complexities is somewhat limited. The present study seeks to fill this gap by examining the 11 June 2009 VORTEX2 case in southeastern Colorado, wherein two supercells were within proximity of each other and a nearby surface boundary. In conjunction with these complexities, the supercell pair also occurred within a low CAPE, high-shear environment, as well as during the nocturnal transition. This study aims to investigate how this supercell pair evolved in response to these environmental complexities.

A combination of local and mobile radar data will be used to assess intensity changes within the supercell pair, focusing on basic metrics such as maximum reflectivity. Dual-Doppler analyses will be utilized to further quantify changes in storm intensity over time, using updraft speed and vertical vorticity. This analysis will be compared with numerous environmental parameters collected from a series of near-inflow soundings launched within the inflow of the supercell pair. A summary timeline will be presented illustrating the connection between changes in storm intensity and environmental variations. The long-term goal of this study is to provide forecasters with some insight into how a supercell evolves in an environment with more complex features, in hopes of improving false alarm rates in these types of storms.