Sunday, 9 February 2003
Lightning Signatures in Convective Storms on the High Plains
Lightning observations of thunderstorms that occurred during the Severe Thunderstorm Electrification and Precipitation Study (STEPS) stationed on the High Plains in the summer of 2000 are discussed. Detailed radar and lightning datasets were collected during this field project to better understand these sometimes destructive and fatal storms. The research results focus on the characteristics of both in-cloud and cloud-to-ground lightning. Cloud-to-ground lightning flash rates coupled with radar observations, severe storm warnings, and storm damage are presented in order to show how lightning and storm intensity are related. The general structure, evolution, and intensity, of the storms are deduced from the radar echo histories. Of the four cases studied, three of them were dominated by positive cloud-to-ground lightning and had tornado warnings issued. Two of those three cases began with a positive cloud-to-ground strike. In-cloud lightning characteristics for one case show that point charge center distributions vary in height during the production of both positive and negative cloud-to-ground lightning as well as during the decrease in cloud-to-ground lightning activity. An understanding of the association between storm intensity and lightning activity may help more easily distinguish better severe and non-severe convective storms.