In this paper, results from nearly 50 electric field soundings through convective regions of mesoscale convective systems (MCSs), isolated supercells, and isolated New Mexican mountain storms are compared and synthesized. These three types of thunderstorm convection are found to have a common, basic electrical structure. Within convective updrafts the basic charge structure has four charge regions, alternating in polarity, and the lowest is positive. Outside updrafts of convection there are typically at least six charge regions, alternating in polarity, and the lowest is again positive. Among the three storm types, there are differences in the heights and temperatures at which the basic four charge regions are found in updrafts. The height (temperature) of the center of the main negative charge region averages 6.93 km (-16 ¿C) in MCS convective region updrafts, 9.12 km (-22 ¿C) in supercell updrafts, and 6.05 km (-7 ¿C) in New Mexican mountain storm updrafts. In updraft soundings through all three storm types, the center height of the main negative charge region increases with increasing average balloon ascent rate and updraft speed at a rate of about 0.3 km per 1 m s-1, with a correlation coefficient of 0.94. A schematic illustrates the basic four- and six-charge structure for thunderstorm convective regions, and it is offered as an improved model for thunderstorm charge structure. ¿ 1998 American Geophysical Union