The Role of Synoptic, Mesoscale, and Urban Forcing on the Historic Atlanta, Georgia Floods of 2009

In September 2009, the metropolitan area of Atlanta, host city for the 2010 American Meteorological Society's Annual Meeting, and surrounding areas in northern Georgia experienced disastrous urban flooding. The United States Geological Survey (USGS) and National Weather Service (NWS) noted record flood levels and cumulative rainfall totals, respectively. The goal of this short communication is to present a brief overview of the synoptic and mesoscale setting leading to the historic Atlanta area flooding, present multiple observational perspectives on cumulative rainfall totals for the event, and consider hypotheses for how the urban land cover affected (1) preferred regions of enhanced rainfall totals around the Atlanta area and (2) the hydrological response. We will also review recent modeling results for Atlanta that support some of the hypotheses discussed.