Radar and Lightning Delineation of Urban-enhanced Thunderstorms for Atlanta, Georgia

Preliminary results of a radar-based, warm-season climatology of convection for Atlanta, Georgia are presented. In particular, we examine how the urban heat island augments convection in this thunderstorm-prone area that has seen substantial increases in population over the last two-to-three decades. The research utilizes National Weather Service Doppler radar composite reflectivity data from 1997-2006. We stratify the radar data according to specific “medium” and “high” reflectivity thresholds, which are used to develop radar climatologies that illustrate “hotspots” of thunderstorm activity.

Additionally, we explore how the Atlanta urban region influences warm season (May through September) cloud-to-ground lightning flashes. Eight years (1995-2003) of flashes from the National Lightning Detection Network are mapped under different wind speed and direction combinations derived from cluster analysis. Overlays of these data in comparison to the radar climatology affirmed a consistent coupling of lightning and convective enhancement around Atlanta.