Radar Indicated Precursors to Severe Weather Development in Left-Moving Supercells

Over the past decade, the introduction of dual-polarization (dual-pol) radar technology has enhanced the understanding of right-moving supercells, however, left-moving supercells have not been studied thoroughly using this technology. Left-moving supercells are thought to be disproportionate producers of large hail when compared to their right-moving counterparts which can lead to costly impacts. This study identifies radar indicated precursors to severe weather in left-moving supercells by utilizing a comprehensive dataset of 896 left-moving supercells from 2011-2022 and an analysis of dual-pol signatures 10, 20, and 30 minutes prior to a report of severe weather. The Supercell Polarimetric Observation Research Kit (SPORK) was used to conduct an analysis of each storm. The output was examined to identify corresponding radar signature precursors to severe weather development. These precursors include changes in updraft size and strength, identified using ZDR columns, changes in reflectivity core magnitudes, and changes in ZDR arc size.