Urban lightning climatology and GIS: An analytical framework from the case study of Atlanta, Georgia

There are three underdeveloped components of urban cloud-to-ground lightning studies: (1) the integration of multiple flash descriptors into more informative summary metrics of flash production, (2) the comparison of flash patterns by thunderstorm type, and (3) the correspondence of urban flashes with underlying land use. We used a GIS to integrate these components as part of an analysis of warm season (May-September) flashes for Atlanta, Georgia, a sprawling region in the thunderstorm-prone southeastern US. Our integrated metric of flash counts and flash days demarcated two large contiguous areas of high flash production in northeast Atlanta. Flashes which developed under conditions related to local surface heating and air mass instability more closely corresponded to urban land uses. Frontally-produced lightning was infrequent over the central city. Instead, peaks in production shifted to the periphery of the urban core, an observation suggestive of building barrier effects.