High-Temporal-Resolution Observations of Tornadogenesis and Tornado Decay Using the Atmospheric Imaging Radar

Phased array radars provide flexible scanning strategies and high-temporal resolution data, which is particularly useful for studying rapidly evolving tornado features with advective timescales of 10 s or less. This study uses high-temporal resolution tornado data collected by the Atmospheric Imaging Radar (AIR) to investigate the vertical evolution of rotation during tornadogenesis and tornado decay, a topic of particular interest in recent phased array radar studies. The AIR is particularly well suited to observe the vertical evolution of rotation within tornadoes and mesocyclones because it collects simultaneous RHIs, which minimizes horizontal advection and tornado evolution during the radar volume. The goal of this type of research is to determine if tornadoes form and dissipate simultaneously or directionally in the vertical, or whether there are multiple modes of tornado evolution.

This study includes one dataset of both tornadogenesis and tornado decay. The first dataset is the 23 May 2016 where the AIR documented a slow moving, tornadic supercell near Woodward, OK. This deployment consists of one hour of continuous, 7-s volumetric updates that span the intensification stages of the supercell and includes the entire lifecycle of a tornado, including tornadogenesis, at 18-20 km in range. The second dataset is the 27 May 2015 Canadian, TX, tornado where the AIR documented tornado decay at 5 km in range, with 5.5-s temporal resolution. The vertical evolution of tornado dissipation and mesocyclone processes were captured with 50-m vertical resolution and observations spanning from 50 m to 2 km above radar level.