Warnings of cloud-to-ground lightning hazard based on total lightning and radar information

In a prior study, we showed that total lightning mapping information provided a significant benefit for producing warnings of the threat of cloud-to-ground (CG) lightning in the particularly difficult case of mesoscale convective systems (MCSs) with large stratiform precipitation regions. Because of the relatively low rate and density of CG flashes in MCS stratiform regions, lightning warnings that are based primarily on CG lightning data often expire while there is still a threat of lightning. Subsequent flashes then can trigger new warnings, which amount to failures to warn because of the expiration of previous warnings. In the prior work, we showed that the rate of failures-to-warn (FTW) could be reduced by a factor of 4 with the inclusion of total lightning mapping data alone. The penalty for this improvement was an increase in total warning duration by about 22%. By including composite reflectivity information, we were able to limit the increase in warning duration to 18%. The present study builds upon the original by including non-MCS storm cases and examining the sensitivity of the method's performance to some of its parameters.