Measurements of lightning have been made with a vertically pointing, 10 cm wavelength Doppler radar and have shown that the lightning echoes produce identifiable coherent peaks in the Doppler spectrum. We have used the evolution of intensity and position of the spectral peaks in the velocity domain to infer some channel properties. From our analysis of 40 lightning echoes, all of them produced by intracloud flashes, we have determined that (1) the ionized lightning channels remain overdense for 25-200 ms, with a mean of 93¿44 ms, which is in agreement with earlier theoretical studies; (2) the decay of the lightning channel radar cross section is exponential with an average rate of about 0.2 dB ms-1; and (3) lightning channels are accelerated most probably by a combination of buoyancy and the earth's magnetic field acting on the hot plasma channel through which a current flows. The resulting channel velocity is apparently due to acceleration from these forces combined with the velocity of the air in which the lightning is embedded. Using the lightning as a tracer, we infer vertical air velocities of -2.0 to 17.5 m s-1, most of which are positive. Our observations suggest that lightning occurs usually within updraft regions.