The North Georgia Lightning Mapping Array: July 21, 2016 Damaging Winds Case Study

The Severe Storms Research Center at the Georgia Tech Research Institute has deployed a lightning mapping array (LMA) that is centered on downtown Atlanta.  Named the North Georgia Lightning Mapping Array, it consists of 12 sites that can detect total lightning data, which is the combination of cloud-to-ground and intracloud lighting.  By accurately determining the time of arrival of the VHF emissions from the lightning at the ground stations, a unique position may be determined for the source.  The source data that is collected makes up the individual pieces of the flash, allowing a three dimensional path of the lightning to be plotted. The data is updated every one minute, and it is streamed in real-time to a web site for partners and to the AWIPS II system at the National Weather Service office in Peachtree City.   The goal of this array is to provide real-time data that improves the situational understanding of NWS forecasters and emergency officials, thereby providing increased lead time for warnings and safety actions.

On July 21, 2016, severe storms that contained high winds and frequent lightning impacted the Atlanta metro region. Across several counties, damage from high winds knocked down large trees onto roads and residences, and numerous structural fires resulted from cloud-to-ground lightning strikes.  The NWS office in Peachtree City issued 20 severe thunderstorm warnings throughout the afternoon. This paper will investigate if any trends emerge from the total lightning data from that day that may have aided forecasters during warning operations.