The Doppler lidar of NOAA/ERL's Wave Propagation Laboratory (WPL) observed a prescribed forest fire that was ignited in the township of Battersby, Ontario, Canada, on 12 August 1988. During the first hour of the fire the lidar saw the smoke column rise nearly straight up to a height of over 1.5 km above ground in response to very light and variable environmental winds below that level. After the first hour of the burn, stronger soutwesterly flow in the boundary layer bent the smoke plume over towards the lidar. During the initial vertical-rise phase of the convective column the lidar observed a strong rotational signature in horizontal scans of the radial velocity. The vorticity of the column is estimated to be 10-2s-1, and this agrees with the rotation rate estimated from a time lapse video cassette recording of the convective column taken from the lidar site. Lidar data were also used to estimate convergence into the column and vertical velocities (w) within the column. Peak w values were estimated to exceed 15 ms-1 at the base of the cumulus congestus cloud that capped the column. We performed Mie backscattering calculations using aircraft-observed size distributions of smoke particles in the smoke plume. The calculations indicated that the major contribution to backscatter came from particles 1.0-3.0 um in diameter, but that the extremely large numbers of small (0.1-1.0 um diameter) particles and a smaller number of larger (3.0-30.0 um diameter) particles also produced strong contributions to the returns. © by the Society of American Foresters. Abstract reproduced by permission.