The incoherent scatter radar located at S¿ndre Str¿mfjord, Greenland (67¿N, 51¿W, 74.5¿&Lgr;) and the EISCAT incoherent scatter facility located in northern Scandinavia (69.5¿N, 19¿E, 66.3¿&Lgr;) both obtained E and F region measurements during the first campaign of the Lower thermosphere Coupling Study (LTCS 1, September 21--25, 1987). Neutral winds deduced from these measurements have been analyzed for their mean flow and tidal components. A number of the altitude profiles for the mean winds and the diurnal and semidiurnal wave components at the two radar locations show similar variations with height, indicating that latitudinal rather than longitudinal effects are dominant in determining the observed wind field. Diurnal tidal amplitudes and phases are reasonably well represented by theoretical model results (Forbes, 1982). The semidiurnal amplitudes and phases, although somewhat consistent between the two radars, are not well represented in equinox tidal model results (Forbes and Vial, this issue), Results from both radars indicate a vertical wavelength for the zonal semidiurnal oscillation of approximately 60 km. During a period of impulsive magnetospheric forcing (September 22--23), winds deduced from measurements at both radars show enhanced eastward flows near midnight accompanied by equatorward winds at Sondrestrom. Comparison with the results of a National Center for Atmospheric Research thermosphere-ionosphere general circulation model (TIGCM) simulation of the LTCS 1 interval shows generally better agreement with the observations at EISCAT than at Sondrestrom. During the period of activity on September 22--23 the TIGCM is reasonably successful at simulating the eastward surge near midnight in the EISCAT (but not in Sondrestrom) observations and the equatorward flow after midnight in the Sondrestrom results. The observed winds in magnetic latitude and magnetic local time coordinates indicate the presence of anticyclonic divergent flow near dusk and cyclonic converging flow near dawn. ¿ American Geophysical Union 1991