Objective Storm Tracking Using Echo Top Height Maxima from High-Resolution Three-Dimensional Radar Observations

Objective tracking of convection has important forecasting and research applications. For example, the U.S. National Weather Service has issued storm-based warnings since 1 October 2007 that seek to improve the specificity and accuracy of tornado, severe thunderstorm, and flood hazards communicated to the public. Accurate objective tracking techniques can enable forecasters to spend less time determining where to define warning areas and more time communicating the hazards associated with each warning. In research, tracking of individual convective cells can facilitate detailed microphysical and dynamical analyses that are only possible in a frame of reference moving with the storm. Prior studies have employed techniques that track radar reflectivity values above some threshold (e.g., 45 dBZ) using only plan view observations or volume estimates. Such algorithms have been shown to identify too few or too many cells, suffer in the presence of merging/splitting storms, and provide conflicting estimates of storm motion. This study will present a novel storm tracking algorithm based on the identification and tracking of echo top height maxima in high-resolution three-dimensional composites of NEXRAD WSR-88D observations in the continental United States. This algorithm is simpler than previous attempts to identify and track convection and improves upon several limitations of low-altitude reflectivity object tracking. Results of the algorithm will be compared to traditional methods for several cases of varying size and organization to demonstrate its performance.