Observations of the total lightning activity inside storms can valuably complement radar as a means of monitoring the location, structure, and severity of convective storms. VHF time-of-arrival measurements from a countywide network of measurement stations can be used to obtain 3-dimensional lightning observations over a 150 to 200 km diameter area and 2-dimensional observations out to a 400 km diameter area. The observations can be made in real time and show the location not only of the storm cores but also the occurrence of strong convective surges in storms. The convective surges have been found to be good indicators of storm intensification and severity. Characteristic lightning-free regions and lightning `holes' (or partial holes) are often observed in conjunction with tornadoes in supercell storms. The structure and inferred polarity of the lightning activity can also provide additional information on the storm nature. Several lightning mapping networks are currently being operated or installed at different locations around the U.S. that will further elucidate on these questions.