Wet Microburst Events Observed with Phased Array Radar

Phased array radar (PAR) offers an advantage over conventional parabolic-antenna based radar systems in its ability to quickly scan the atmosphere with an electronically steered beam. This gives users of PAR data the opportunity to better observe rapidly evolving hazardous weather. This study focuses on one such phenomenon, the wet microburst, a potential safety hazard to avaition. From PAR data collected at the National Weather Radar Testbed located in Norman, Oklahoma during 2007-2012, 27 microburst-producing storms and 22 storms not producing a microburst were identified and analyzed to determine the potential improvements that PAR offers compared to the current operational WSR-88D system. Based on prior research of microburst precursors, the trends of several parameters measuring vertical reflectivity and convergence characteristics in the storms were selected for analysis. The ability of these selected parameters to discriminate between storms that produce microburst events and those that do not will be presented, along with probability-of-detection and lead times between the identification of these parameters and the initial time of hazardous outflow (divergence) near the surface.