Climatology of cloud-to-ground lightning in Georgia, USA, 1992-2003

A 12-year climatology of lightning cloud-to-ground flash activity for Georgia revealed the existence of three primary regions of high lightning activity: the area surrounding the Atlanta Metropolitan Statistical Area, east-central Georgia along the fall line, and along the Atlantic coast. Over 8.2 million ground flashes were identified during the climatology. July was the most active lightning month and December was the least active. Annual, seasonal, and diurnal distributions of cloud-to-ground flashes were also examined. These patterns illustrated the interacting effects of land cover, topography, and convective instability in enhancing lightning activity throughout Georgia. A synoptic analysis of the ten highest lightning days during the summer and winter revealed the importance of frontal boundaries in organizing convection and high lightning activity during both seasons. The prominence of convective instability during the summer and strong dynamical forcing in the winter was also found to lead to outbreaks of high lightning activity.