The main purpose of this study is to show that warnings of cloud-to-ground (CG) lightning based on data provided by VHF total lightning mapping systems are significantly better than those provided by CG lightning detection data alone. Initial findings in this regard (presented in a previous study) are based on over 20 storms observed by the Vaisala Lightning Detection and Ranging (LDAR II) VHF total lightning mapping network in the Dallas-Fort Worth (DFW) metropolitan area in 2005. The present study shows those results and then expands on them in a few ways. First, we present additional analysis using VHF lightning mapping systems both in the DFW and Tucson, Arizona, areas. These additional results are based on VHF interferometry networks, in order to demonstrate that, for the CG warning problem, VHF time-of-arrival and interferometry systems provide equivalent performance. Second, we present an analysis of the warning capabilities of electrostatic field data obtained from a number of months of continuous observations by a pair of electric field mills. To our knowledge, this is the first attempt to analyze continuous field mill observations specifically to determine their impact on warnings of CG lightning.