An Examination of tornadic Signatures Associated with the May 3, 1999 Outbreak Using a New WSR-88D Scaning Strategy

Throughout the afternoon and evening of the May 3, 1999 Central Oklahoma and Southern Kansas experienced a significant tornadic outbreak. Cyclic supercells spawned over 70 tornadoes causing over 40 deaths and extensive property damage.

An unprecedented WSR-88D data set was collected during part of this event. Not only was the operational KTLX dataset archived, new Volume Coverage Patterns (VCPs) were also collected using the OSF testbed KCRI WSR-88D. Two types of new VCPs were used to collect data. The first types are VCPs designed with denser lower and upper- level coverages (through additional tilts) in the vertical for better resolution and cone of silence mitigation. A second type of VCP design uses scans collected at the same elevation angle with different Nyquist velocities. These scans are then merged providing up to three velocity estimates at each gate. This procedure (termed the Multi-PRF Dealiasing Algorithm) can eliminate range folded data while providing cleanly dealiased velocity fields for processes such as the Mesocyclone and Tornado Detection Algorithms (MDA and TDA).

This paper will present an examination of the May 3, 1999 mesocyclone and tornadic signatures using the new scanning strategies compared to data collected operationally. It will be shown the new strategies are clearly superior to the current WSR- 88D scanning strategies.

Presentation: If it is decided to have a special session devoted to May 3, I would like to be part of that. Otherwise, a poster presentation would be fine.