Polarimetric Characteristics of Tornadic Debris Fallout during the28 May 2019 Lawrence/Kansas City, KS Tornado

During the late afternoon and evening on 28 May 2019, an EF-4 tornado affected areas of Northeast Kansas, including the outskirts of Lawrence, KS and Kansas City metropolitan area. Shortly after EF-3 and EF-4 damage were reported, a large area of lofted debris was evident in the KTWX (Topeka, KS) and KEAX (Kansas City, MO) WSR-88D polarimetric moments. This area of debris drifted northward, resulting in tornadic debris fallout many kilometers north of the tornado. Over 75 km away from the tornado’s track, at Kansas City International Airport, falling debris forced crews to shut down the airfield for over 3 hours while debris was cleared from the taxiways and runways. This study presents a statistical analysis of the polarimetric characteristics of the lofted tornadic debris plume, including distributions of the polarimetric moments, distribution of the plume height, and size and directionality of the plume. Each of these analyses is performed on a space-time grid in order to provide temporal context during debris fallout. Differences between the tornadic debris signature and the lofted debris plume are addressed. The data collection and processing scheme is presented in detail, and applicability of the methodology to other cases is discussed.