Lightning stroke occurrences often appear to have been sorted polarity-wise in both space and time, especially in winter storms. This phenomenon raises a number of important questions related to charge separation in meteorological environments which may favor one polarity over the other. If the lightning locating hardware is correctly identifying ground stroke polarities, then additional considerations need be given to charging processes that are operative when the main convective phase of the thunderstorm is over. Clearly, a check on the validity of the network polarity determinations is warranted. We have studied the correctness of the polarity assignments as determined by the LLP hardware used in the SUNYA lightning detection network. From a very limited sample of waveforms recorded during the winters of 1986--1987 and 1987--1988, we conclude that present acceptance criteria are adequate, provided that distances from strokes to stations do not exceed 600 km. Polarity determinations with present algorithms can often be incorrect for strokes beyond 700 km as a result of the misidentification of the ionospheric reflection for the strongly attenuated ground wave. ¿ American Geophysical Union 1989