Thunderstorm Characteristics of Cloud-to-Ground Lightning at the Kennedy Space Center, Florida: A Study of Lightning Initiation Signatures as Indicated by the WSR-88D

Abstract

The operational potential for predicting the onset of cloud-to-ground lightning is examined. WSR-88D reflectivity echoes were analyzed for 39 airmass thunderstorms that developed over the NASA Kennedy Space Center, Florida, to determine the best lightning initiation signature. This study examined thunderstorms in the months of May?September 1992?97. These storms were studied in conjunction with cloud-to-ground (CG) lightning flash locations from the National Lightning Detection Network. From a time series of radar echoes, it was found that the 40-dBZ echo detected at the ?10°C temperature height is the best indicator for predicting the beginning of CG lightning activity. The observed median lag time, or warning time, between this lightning initiation signature and the first CG lightning flashes was 7.5 min. Other lightning initiation signatures examined at ?15° and ?20°C temperature heights yielded shorter warning times.