Analysis of Cloud-to-Ground Lightning in Hurricane Andrew.

In August of 1992, Andrew joined a long list of tropical storms that have caused considerable damage and loss of life as they made landfall near a populated area. However, Andrew was unique in the sense that no previous landfalling tropical storm in the United States has provided such an excellent opportunity to study the cloud-to-ground CG lightning associated with this type of storm. While numerous thunderstorm systems, particularly the severe storms of the Great Plains, have been studied for lightning characteristics, the ability to conduct similar studies on hurricanes has been limited due to the small number which have occurred since the relatively new National Lightning Detection Network has been operational. 17,036 CG strikes over a 77 hour period were attributed to either the eyewall region or the primary spiral rainbands of Andrew. The overall distribution by polarity of the lightning was found to be 2.1 positive and 97.9 negative. As the storm was dissipating over land in Mississippi all lightning observed near the pressure center was positive. Throughout the lifetime of the storm, the negative first stroke peak current decreased while the positive first stroke peak current increased.