3B.6
ARMOR dual-polarimetric radar observations of tornadic debris signatures
Walter A. Petersen, NASA / MSFC, Huntsville, AL ; and L. D. Carey, K. R. Knupp, C. J. Schultz, and E. V. Johnson
During the Super-Tuesday tornado outbreak of 5-6 February 2008, two EF-4 tornadoes occurred in Northern Alabama within 75 km range of the University of Alabama in Huntsville (UAH) Advanced Radar for Meteorological and Operational Research (ARMOR, C-band dual-polarimetric). This study will present an analysis of ARMOR radar-indicated dual-polarimetric tornadic debris signatures. The debris signatures were associated with spatially-confined large decreases in the copolar correlation coefficient (rhoHV) that were embedded within broader mesocyclone “hook” signatures. These debris signatures were most obviously manifest during the F-3 to F-4 intensity stages of the tornado(s) and extended to altitudes of approximately 3 km. The rhoHV signatures of the tornadic debris were the most easily distinguished relative to other polarimetric and radial velocity parameters (e.g., associated with large hail and/or the incipient mesocyclone). Based on our analysis, and consistent with the small number of studies found in the literature, we conclude that dual-polarimetric radar data offer at least the possibility for enhancing specificity and confidence in the process of issuing tornado warnings based only on radar detection of threatening circulation features. Recorded presentation
Session 3B, Polarimetric Radar Observations and Lightning
Monday, 27 October 2008, 1:30 PM-3:00 PM, South Ballroom
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