Electric field measurements have been acquired inside an electrically active cell of a multicelled severe storm in Oklahoma with a free balloon-borne instrument. The electrical measurements are analyzed in conjunction with standard weather radar and Doppler radar observations and standard meteorological measurements of the radiosonde in order to relate the inferred electrical structure with the precipitation and kinematic features of the dell. The precipitation and kinematic characteristics of the storm are consistent with those of the general model for a ''typical'' multicelled severe storm in a mature stage. The cell exhibited a bipolar charge structure with negative charge below positive charge, which was distributed throughout the upper portion of the cloud. The average charge concentrations of the two regions were estimated to be -1.2 and 0.15 nC m-3, respectively. The upper positive charge was approximately 6 km in vertical extent, nonuniformly distributed, and was coincident with generally upward moving air. The lower negative charge was less than 1 km in vertical extent, centered near the -9 ¿C atmospheric temperature level, and coincident with downdraft air in moderate precipitation. Near the top of the negative region, concentrated charge of approximately 17 nC m-3 was measured with a vertical extent of at least 40 m. A screening layer of negative charge was detected at the upper boundary of the cloud. The layer was 200--250 m thick with an average charge concentration of -1.5 nC m-3. ¿ American Geophysical Union 1987